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%%%%%%%%%%%%%%      Bibliographical database for the book   %%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%                                              %%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%             TRUST REGION  METHODS            %%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%                                              %%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%   by A.R. Conn, N.I.M. Gould and Ph.L. Toint %%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%                                              %%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%         (SIAM, Philadelphia, 2000)           %%%%%%%%%%%%%%%%%
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%
%   Copyright: Andrew R. Conn, Nicholas I. M. Gould and Philippe L. Toint
%
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%
%                     This version: 18 II 2001
%
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%
%   The following works have been cited in the above mentioned book. 
%   Some are general references to background material, while others 
%   are central to the development of the trust-region methods we have 
%   covered. For those references directly relating to trust-region 
%   methods, we have included a short summary of the work's contents. 
%   We have deliberately not included any but the most relevant of the
%   literally thousands of citations to the Levenberg-Morrison-Marquardt
%   method.
%
%   We would be delighted to receive any corrections or updates to this list.
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  STRING definitions
%
%  Journals

@string{AOR = "Annals of Operations Research"}
@string{BIT = "BIT"}
@string{COAP = "Computational Optimization and Applications"}
@string{COMPJ = "Computer Journal"}
@string{CSB = "Chinese Science Bulletin"}
@string{IJNME = "International Journal on Numerical Methods in Engineering"}
@string{IMAJNA = "IMA Journal of Numerical Analysis"}
@string{JIMA = "Journal of the Institute of Mathematics and its Applications"}
@string{JOTA = "Journal of Optimization Theory and Applications"}
@string{JCAM = "Journal of Computational and Applied Mathematics"}
@string{JCM = "Journal of Computational Mathematics"}
@string{LAA = "Linear Algebra and its Applications"}
@string{MC = "Mathematics of Computation"}
@string{MOR = "Mathematics of Operations Research"}
@string{MP = "Mathematical Programming"}
@string{MPA = "Mathematical Programming, Series~A"}
@string{MPB = "Mathematical Programming, Series~B"}
@string{MPS = "Mathematical Programming Studies"}
@string{NUMMATH = "Numerische Mathematik"}
@string{OMS = "Optimization Methods and Software"}
@string{ORSAC = "ORSA Journal on Computing"}
@string{RAIRO-OR = "RAIRO-Recherche Op\'{e}rationnelle---Operations Research"}
@string{RAIRO-MM = "RAIRO-Mathematical Modelling and Numerical
        Analysis---Mod\'{e}lisation Math\'{e}matique et Analyse Num\'{e}rique"}
@string{SIADM = "SIAM Journal on Algebraic and Discrete Methods"}
@string{SINUM = "SIAM Journal on Numerical Analysis"}
@string{SICON = "SIAM Journal on Control and Optimization"}
@string{SIOPT = "SIAM Journal on Optimization"}
@string{SIMAA = "SIAM Journal on Matrix Analysis and Applications"}
@string{SISSC = "SIAM Journal on Scientific and Statistical Computing"}
@string{SISC = "SIAM Journal on Scientific Computing"}
@string{SIAPM = "SIAM Journal on Applied Mathematics"}
@string{SIREV = "SIAM Review"}
@string{TOMS = "Transactions of the ACM on Mathematical Software"}

%  Places

@string{ANL = "Argonne National Laboratory"}
@string{ANL-ADDRESS = "Argonne, Illinois, USA"}
@string{BELLLABS = "Bell Laboratories"}
@string{BELLLABS-ADDRESS = "Murray Hill, New Jersey, USA"}
@string{CAAM = "Department of Computational and Applied Mathematics,
        Rice University"}
@string{CRPC = "Center for Research on Parallel Computers"}
@string{COIMBRA = "Department of Mathematics, University of Coimbra"}
@string{COIMBRA-ADDRESS = "Coimbra, Portugal"}
@string{DAMTP = "Department of Applied Mathematics and Theoretical Physics,
        Cambridge University"}
@string{DAMTP-ADDRESS = "Cambridge, England"}
@string{DUNDEE = "Department of Mathematics, University of Dundee"}
@string{DUNDEE-ADDRESS = "Dundee, Scotland"}
@string{ICMSEC = "Institute of Computational Mathematics and  
                  Scientific/Enginering Computing, Chinese Academy of Sciences"}
@string{ICMSEC-ADDRESS = "Beijing, China"}
@string{RICE = "Department of Mathematical Sciences, Rice University"}
@string{RICE-ADDRESS = "Houston, Texas, USA"}
@string{ACRI-CORNELL = "Advanced Computing Research Institute, Cornell Theory
        Center"}
@string{CS-CORNELL = "Department of Computer Science, Cornell University"}
@string{CORNELL-ADDRESS = "Ithaca, New York, USA"}
@string{FUNDP = "Department of Mathematics, University of Namur"}
@string{FUNDP-ADDRESS = "Namur, Belgium"}
@string{HAMBURG = "Institute of Applied Mathematics, University of Hamburg"}
@string{HAMBURG-ADDRESS = "Hamburg, Germany"}
@string{HARWELL = "{AERE} {H}arwell Laboratory"}
@string{HARWELL-ADDRESS = "Harwell, Oxfordshire, England"}
@string{HATFIELD = "Numerical Optimization Center, Hatfield Polytechnic"}
@string{IBMWATSON = "T. J. Watson Research Center"}
@string{IBMWATSON-ADDRESS = "Yorktown Heights, NY, USA"}
@string{ICASE = "Institute for Computer Applications in Science and
        Engineering"}
@string{ICASE-ADDRESS = "NASA Langley Research Center Hampton, Virginia, USA"}
@string{MADISON = "Computer Sciences Department, University of Wisconsin"}
@string{MADISON-ADDRESS = "Madison, Wisconsin, USA"}
@string{MCCM = "Manchester Centre for Computational Mathematics"}
@string{MCCM-ADDRESS = "Manchester, England"}
@string{NIST = "Applied and Computational Mathematics Division"}
@string{NIST-ADDRESS = "National Institute of Standards and Technology,
        Gaithersburg, Maryland, USA"}
@string{NPL = "National Physical Laboratory"}
@string{NPL-ADDRESS = "London, England"}
@string{NWU = "Department of Electrical Engineering and Computer Science,
        Northwestern University"}
@string{NWU-ADDRESS = "Evanston, Illinois, USA"}
@string{OTC = "Optimization Technology Center, Argonnne National Laboratory"}
@string{RAL = "Rutherford Appleton Laboratory"}
@string{RAL-ADDRESS = "Chilton, Oxfordshire, England"}
@string{STANFORD = "Department of Operations Research, Stanford University"}
@string{STANFORD-ADDRESS = "Stanford, California, USA"}
@string{MATHWATERLOO = "Faculty of Mathematics, University of Waterloo"}
@string{MATHWATERLOO-ADDRESS = "Waterloo, Ontario, Canada"}
@string{UNICAMP = "Department of Applied Mathematics, IMECC-UNICAMP"}
@string{UNICAMP-ADDRESS = "Campinas, Brasil"}

%  Publishers

@string{ADW = "Addison-Wesley Publishing Company"}
@string{ADW-ADDRESS = "Reading, Massachusetts, USA"}
@string{AMS = "American Mathematical Society"}
@string{AMS-ADDRESS = "Providence, Rhode-Island, USA"}
@string{AP = "Academic Press"}
@string{AP-ADDRESS = "London"}
@string{CUP = "Cambridge University Press"}
@string{CUP-ADDRESS = "Cambridge, England"}
@string{FREEMAN = "W. H. Freeman and Company"}, "}
@string{FREEMAN-ADDRESS = "New York and San Francisco"}
@string{KLUWER = "Kluwer Academic Publishers"}
@string{KLUWER-ADDRESS = "Dordrecht, The Netherlands"}
@string{LONGMAN = "Longman Scientific {\&} Technical"}
@string{LONGMAN-ADDRESS = "Harlow, Essex, England"}
@string{MACGH = "McGraw-Hill"}
@string{MACGH-ADDRESS = "New York, USA"}
@string{NH = "North Holland"}
@string{NH-ADDRESS = "Amsterdam, The Netherlands"}
@string{OUP = "Oxford University Press"}
@string{OUP-ADDRESS = "Oxford, England"}
@string{PH = "Prentice-Hall"}
@string{PH-ADDRESS = "Englewood Cliffs, New Jersey, USA"}
@string{WILEY = "J. Wiley and Sons"}
@string{WILEY-ADDRESS = "Chichester, England"}
@string{SIAM = "SIAM"}
@string{SIAM-ADDRESS = "Philadelphia, USA"}
@string{SPRINGER = "Springer Verlag"}
@string{SPRINGER-ADDRESS = "Heidelberg, Berlin, New York"}
@string{WSP = "World Scientific Publishers"}
@string{WSP-ADDRESS = "Singapore"}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% REFERENCES %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%%% A %%%

@misc{Alex98,
 author		= {N. M. Alexandrov},
 title		= {A Trust-Region Algorithm for Bilevel Optimization},
 howpublished	= {Presentation at the Optimization 98 Conference, Coimbra},
 year		= 1998,
 abstract	= {This paper concerns a trust-region method for solving
		   nonlinear bilevel optimization problems. No special
		   assumptions on structure, such as separability or
		   convexity, are made. Approaches to bilevel optimization
		   usually fall into one of three categories. One set converts
		   the bilevel program into a single-level NLP by using the
		   KKT conditions of the lower-level system as constraints for
		   the upper-level problem. Another approximates problems of
		   both levels by series of unconstrained problems resulting
		   in double-penalty methods. The third category consists of
		   descent methods on the upper level problem with the use of
		   some gradient information from the lower-level problem. The
		   first two approaches suffer from a number of difficulties.
		   The algorithm presented here is related to those of the
		   third category and it can be extended to multilevel
		   optimization. The development of the algorithm is motivated
		   by applications in multidisciplinary optimization. The
		   paper presents the algorithm, its analysis, and a number of
		   numerical examples. It also contrasts the algorithm with a
		   representative example of the first class---the
		   collaborative optimization algorithm.},
 summary	= {A trust-region method for solving nonlinear bilevel
		   optimization problems is presented without any special
		   assumptions on structure, such as separability or
		   convexity. The algorithm is related to descent methods on
		   the upper level problem which use some gradient information
		   from the lower-level problem, and can be extended to
		   multilevel optimization. It is motivated by applications in
		   multidisciplinary optimization. The algorithm, its
		   analysis, and a number of numerical examples are discussed
		   and contrasted with the collaborative optimization method.}}
 
@techreport{AlexDenn94a,
 author		= {N. M. Alexandrov and J. E. Dennis},
 title		= {Multilevel algorithms for nonlinear optimization},
 institution	= ICASE, address = ICASE-ADDRESS,
 number		= {94-53}, year = 1994,
 abstract	= {Multidisciplinary design optimization (MDO) gives rise to
		   nonlinear optimization problems characterized by a large
		   number of constraints that naturally occur in blocks. We
		   propose a class of multilevel optimization methods
		   motivated by the structure and number of constraints and by
		   the expense of the derivative computations for MDO. The
		   algorithms are an extension to the nonlinear programming
		   problem of the successful class of local
		   \citebb{Brow69}--\citebb{Bren73} algorithms for nonlinear
		   equations. Our extensions allow the user to partition
		   constraints into arbitrary blocks to fit the application,
		   and they separately process each block and the objective
		   function, restricted to certain subspaces. The methods use
		   trust regions as a globalization strategy, and they have
		   been shown to be globally convergent under reasonable
		   assumptions. The multilevel algorithms can be applied to
		   all classes of MDO formulations. Multilevel algorithms for
		   solving nonlinear systems of equations are a special case
		   of the multilevel optimization methods. In this case, they
		   can be viewed as a trust-region globalization of the
		   Brown-Brent class.},
 summary	= {Multidisciplinary design optimization (MDO) gives rise to
		   nonlinear optimization problems with a large number of
		   constraints that occur in blocks. A class of multilevel
		   optimization methods motivated by their structure and
		   number and by the expense of the derivative computations
		   for MDO is proposed. The algorithms are an extension of the
		   local \citebb{Brow69}--\citebb{Bren73} algorithms for
		   nonlinear equations. They allow the user to partition
		   constraints into arbitrary blocks to fit the application,
		   and they separately process each block and the objective
		   function, restricted to certain subspaces. The methods use
		   trust regions as a globalization strategy, and are globally
		   convergent.}}

@techreport{AlexDenn94b,
 author		= {N. M. Alexandrov and J. E. Dennis},
 title		= {Algorithms for bilevel optimization},
 institution	= ICASE, address = ICASE-ADDRESS,
 number		= {94--77}, year = 1994,
 abstract	= {General multilevel nonlinear optimization problems arise in
		   design of complex systems and can be used as a means of
		   regularization for multicriteria optimization problems.
		   Here for clarity in displaying our ideas, we restrict
		   ourselves to general bilevel optimization problems, and we
		   present two solution approaches. Both approaches use a
		   trust-region globalization strategy, and they can be easily
		   extended to handle the general multilevel problem. We make
		   no convexity assumptions, but we do assume that the problem
		   has a nondegenerate feasible set. We consider necessary
		   optimality conditions for the bilevel problem formulations
		   and discuss results that can be extended to obtain
		   multilevel optimization formulations with constraints at
		   each level.},
 summary	= {Two solution approaches are presented for  general bilevel
		   optimization problems. Both use a trust-region
		   globalization strategy, and can be extended to handle the
		   general multilevel problem. No convexity assumptions are
		   made, but it is assumed that the problem has a
		   non-degenerate feasible set. Necessary optimality conditions
		   for the bilevel problem formulations are considered and the
		   results extended to obtain multilevel optimization
		   formulations with constraints at each level.}}

@techreport{AlexDenn99,
 author		= {N. M. Alexandrov and J. E. Dennis},
 title		= {A Class of General Trust-Region Multilevel Algorithms
		   for Nonlinear Constrained Optimization: Global Convergence
		   Analysis}, 
 institution	= CRPC, address = RICE-ADDRESS,
 number         = {TR99786-S}, year = 1999,
 abstract	= {This paper presents a braod class of trust-region multilevel
		   algorithms for solving large, nonlinear, equality
		   constrained problems, as well as a global convergence
		   analysis for the class.  The work is motivated by 
		   engineering optimization problems with naturally occurring,
		   densely or fully-coupled subproblem structure. The
		   constraints are partitioned into blocks, the number and
		   composition of which are determined by the application.  At
		   every iteration, a multilevel algorithm minimizes models of 
		   the reduced constraint blocks, followed by a reduced model
		   of the objective function, in a sequence of subproblems,
		   each of which yields a substep.  The trial step is the sum
		   of these substeps.  The salient feature of the 
		   multilevel class is that there is no prescription on how
		   the substeps must be computed.  Instead, each substep is
		   required to satisfy mild sufficient decrease and
		   boundedness conditions on the restricted model that it 
		   minimizes.  Within a single trial step computation, all
		   substeps can be computed by different methods appropriate
	           to the nature of each subproblem. This feature is
		   important for the applications of interest in that it allows 
		   for a wide variety of step-choice rules.  The trial step is
		   evaluated via one of two merit functions that take into
		   account the autonomy of subproblem processing.  The
		   multilevel procedure presented in this work is sequential.
		   If a problem exhibits full or partial separability, or if
		   separability is induced by introducing auxiliary variables,
		   then the multilevel algorithms can easily be stated in
		   parallel form.  However, since this work is devaoted to
		   analysis, we consider the most general case, that of a
		   fully coupled problem.}, 
 summary	= {A globally convergent class of trust-region multilevel
		   algorithms for solving equality constrained problems is
		   presented, motivated by engineering optimization problems
		   with densely subproblem structure. The constraints are
		   partitioned into blocks. At every iteration, a multilevel
		   algorithm minimizes models of the reduced constraint
		   blocks, followed by a reduced model of the objective 
		   function, each yielding a substep.  The trial step is the sum
		   of these substeps. Each substep is required to satisfy
		   sufficient decrease and boundedness conditions on its
		   restricted model and can be computed by a specialized method.
		   The trial step is evaluated via one of two merit functions
		   that take into account the autonomy of subproblem
		   processing.}} 

@article{AlexDennLewiTorc98,
 author		= {N. M. Alexandrov and J. E. Dennis and R. M. Lewis and V.
		   Torczon},
 title		= {A Trust Region Framework for Managing the Use of
		   Approximation Models},
 journal	= {Structural Optimization},
 volume		= 15, number = 1, pages = {16--23}, year = 1998,
 abstract	= {This paper presents an analytically robust, globally
		   convergent approach to managing the use of approximation
		   models of various fidelity in optimization. By robust
		   global behavior we mean the mathematical assurance that the
		   iterates produced by the optimization algorithm, started at
		   an arbitrary initial iterate, will converge to a stationary
		   point or local optimizer for the original problem. The
		   approach we present is based on the trust region idea from
		   nonlinear programming and is shown to be provably
		   convergent to a solution of the original high-fidelity
		   problem. The proposed method for managing approximations in
		   engineering optimization suggests ways to decide when the
		   fidelity, and thus the cost, of the approximations might be
		   fruitfully increased or decreased in the course of the
		   optimization iterations. The approach is quite general. We
		   make no assumptions on the structure of the original
		   problem, in particular, no assumptions of convexity and
		   separability, and place only mild requirements on the
		   approximations. The approximations used in the framework
		   can be of any nature appropriate to an application; for
		   instance, they can be represented by analyses, simulations,
		   or simple algebraic models. This paper introduces the
		   approach and outlines the convergence analysis.},
 summary	= {A robust, globally convergent approach to using
		   approximation models of various fidelity is presented. It
		   is based on trust regions and converges to a solution
		   of the original high-fidelity problem. The method suggests
		   ways to decide when the fidelity, and thus the cost, of the
		   approximations might be altered in the course of the
		   iterations. No assumptions on the structure
		   of the original problem, such as convexity and
		   separability, are made, and the requirements on the
		   approximations are mild. These can be of
		   any nature appropriate to an application; for instance,
		   they can be represented by analyses, simulations, or simple
		   algebraic models.}}

@article{Aliz95,
 author		= {F. Alizadeh},
 title		= {Interior point methods in semidefinite programming with
		   applications to combinatorial optimization},
 journal	= SIOPT,
 volume		= 5, number = 1, pages = {13--51}, year = 1995}

@inproceedings{Alle95,
 author         = {D. M. Allen},
 title          = {Tailoring nonlinear least squares algorithms for the 
                   analysis of compartment models},
 booktitle      = {Computationally Intensive Statistical Methods. 
                   Proceedings of the 26th Symposium on the Interface,
                   Fairfax Station, VA, USA},
 editor         = {J. Sall and A. Lehman},
 volume         = 26, pages = {533--535}, year = 1995,
 abstract       = {Compartment models are widely used in
                   pharmacokinetics. Our objective is to fit compartment
                   models to data. General numerical optimization
                   methods frequently perform poorly for this purpose. A
                   good book on numerical optimization, such as by
                   J.E. Dennis and R.B. Schnabel, describes multiple
                   techniques and discusses the advantages and
                   disadvantages of each. In order to implement these
                   methods in a software product, one must make a number
                   of decisions. For example, should a line search
                   method or a trust region method be used? How should
                   variables on widely different scales be handled? In
                   general, these are questions without clear-cut
                   answers. Compartment models are defined by linear
                   differential equations. Consequently, compartment
                   models have a particular structure. We have tailored
                   general optimization methods to exploit this
                   structure. Through study and experimentation we have
                   found workable answers to the questions posed above.},
 summary        = {Compartment models are defined by linear
                   differential equations and are widely used in
                   pharmacokinetics. It is shown how general optimization
		   methods, including linesearch and trust-region methods
		   can be tailored to exploit the special structure of 
		   such models.}}

@article{AllgBohmPotrRhei86,
 author		= {E. L. Allgower and K. B\"{o}hmer and F. A. Potra and W. C.
		   Rheinboldt},
 title		= {A mesh-independence principle for operator equations and
		   their discretizations},
 journal	= SINUM,
 volume		= 23, number = 1, pages = {160--169}, year = 1986}

@article{Amay85,
 author		= {J. Amaya},
 title		= {On the convergence of curvilinear search algorithms in
		   unconstrained optimization},
 journal	= {Operations Research Letters},
 volume		= 4, number = 1, pages = {31--34}, year = 1985,
 abstract	= {The purpose of this paper is to unify the conditions under
		   which curvilinear algorithms for unconstrained optimization
		   converge. Particularly, two gradient path approximation
		   algorithms and a trust-region curvilinear algorithm are
		   examined in this context.},
 summary	= {The conditions under which curvilinear algorithms for
		   unconstrained optimization converge are unified. Two
		   gradient path approximation algorithms and a trust-region
		   curvilinear algorithm are examined in this light.}}

@book{AndeBaiBiscDemmDongDuCrGreeHammMcKeOstrSore95,
 author		= {E. Anderson and Z. Bai and C. Bischof and J. Demmel and J.
		   J. Dongarra and J. DuCroz and A. Greenbaum and S.
		   Hammarling and A. McKenney and S. Ostrouchov and D. C.
		   Sorensen},
 title		= {LAPACK Users' Guide},
 publisher	= SIAM, address = SIAM-ADDRESS,
 edition	= {second}, year = 1995}

@inproceedings{AndeGondMeszXu96,
 author		= {E. D. Andersen and J. Gondzio and C. M\'{e}sz\'{a}ros and
		   X. Xu},
 title		= {Implementation of interior point methods for large scale
		   linear programming},
 crossref	= {Terl96}, pages = {189--252}}

@article{AndrVice99,
 author		= {D. A. Andrews and L. N. Vicente},
 title		= {Characterization of the Smoothness and Curvature of a
		   Marginal Function for Trust-Region Problem},
 journal        = MP,
 volume         = 84, number = 1, pages = {123--137}, year = 1999,
 abstract	= {This paper studies the smoothness and curvature of a
		   marginal function for a trust-region problem. In this
		   problem, a quadratic function is minimized over an
		   ellipsoid. The marginal function considered is obtained by
		   perturbing the trust radius, i.e. by changing the size of
		   the ellipsoid constraint. The values of the marginal
		   function and of its first and second derivatives are
		   explicitly calculated in all possible scenarios. A complete
		   study of the smoothness and curvature of this marginal
		   function is given. The main motivation for this work arises
		   from an application in statistics.},
 summary	= {The smoothness and curvature of a marginal function for a
		   scaled $\ell_2$ trust-region problem are studied. The
		   marginal function is obtained by perturbing the trust
		   radius. The values of the marginal function and of its
		   first and second derivatives are explicitly calculated in
		   all possible cases. A complete study of the smoothness and
		   curvature is given. The work is motivated by an application
		   in statistics.}}

@techreport{AntoGior96,
 author		= {F. Antonio and G. Giorgio},
 title		= {A Bundle type Dual-ascent Approach to Linear
		   Multi-Commodity Min Cost Flow Problems},
 institution	= {Pisa University}, address = {Italy},
 number		= {TR96-01}, year = 1996,
 abstract	= {We present a cost decomposition approach to Linear
		   Multicommodity Min Cost Flow problems, based on dualizing
		   the mutual capacity constraints: the resulting Lagrangian
		   Dual is solved by means of a new, specialized Bundle
		   type-dual ascent algorithm. Although decomposition
		   approaches are generally believed not to be competitive,
		   even for the solution of large-scale network structured
		   problems, we present evidence based on extensive
		   computational comparisons that a careful implementation of
		   a decomposition algorithm can outperform several other
		   approaches, especially on problems where the number of
		   commodities is "large" w.r.t. the size of the graph. Our
		   specialized Bundle algorithm is characterised by a new
		   heuristic for the trust region parameter handling, and
		   embeds a custom, fast Quadratic Programming solver that
		   permits the implementation of a Lagrangian variables
		   generation strategy. The Lagrangian Relaxation solver is
		   capable of exploiting the structural properties of the
		   single-commodity Min Cost Flow subproblems to avoid using a
		   "generic" MCF solver whenever it is possible. The proposed
		   approach can be easily extended to handle extra constraints
		   or variants such as the Nonsimultaneous Multicommodity
		   problem. In our computational experience, we also studied
		   the impact on the relative efficiencies of the different
		   approaches tested of some characteristics, such as the
		   number of commodities w.r.t. the total size of the problem.},
 summary	= {A cost decomposition approach to Linear Multicommodity Min
		   Cost Flow problems, based on dualizing the mutual capacity
		   constraints, is presented: the resulting Lagrangian Dual is
		   solved by means of a specialized Bundle type-dual ascent
		   algorithm. Extensive computational comparisons show that a
		   careful implementation of a decomposition algorithm can
		   outperform several other approaches, especially on problems
		   where the number of commodities is ``large'' with respect to
		   the size of the graph. The specialized Bundle algorithm is
		   characterised by a heuristic for handling the trust region
		   parameter, and embeds a specialized, efficient quadratic
		   programming solver that permits the implementation of a
		   Lagrangian variables generation strategy. Numerical tests
		   illustrate the relative efficiencies of the different
		   approaches.}}

@article{AriyLau92,
 author		= {K. A. Ariyawansa and D. T. M. Lau},
 title		= {On the Updating Scheme in a Class of Collinear Scaling
		   Algorithms for Sparse Minimization},
 journal	= JOTA,
 volume		= 75, number = 1, pages = {183--193}, year = 1992,
 abstract       = {Sorensen has proposed a class of algorithms for
		   sparse unconstrained minimization where the sparsity 
		   pattern of the Cholesky factors of the Hessian is known.
		   His updates at each iteration depend on the choice of a
		   vector, and in this reference the question of choosing this
		   vector is essentially left open.  In this note, we propose
		   a variational problem whose solution may be used to choose
		   that vector.  The major part of the computation of a
		   solution of this variational problem is similar to the 
		   computation of a trust-region step in unconstrained
		   optimization.  Therefore, well-developed techniques
		   available for the latter problem can be used to compute
		   this vector and to perform the updating.}, 
 summary	= {The techniques for solving the trust-region subproblem are
		   used for solving a variational problem arising in the
		   updating of sparse Hessian approximations for large-scale
		   unconstrained optimization.}} 

@techreport{AshcGrimLewi95,
 author		= {C. Ashcraft and R. G. Grimes and J. G. Lewis},
 title		= {Accurate Symmetric Indefinite Linear Equation Solvers},
 institution	= {Boeing Computer Services},
 address	= {Seattle, Washington, USA},
 year		= 1995}

@mastersthesis{Auer93,
 author		= {G. Auer},
 title		= {Numerische {B}ehandlung von {T}rust {R}egion {P}roblemen},
 school		= {Technical University of Graz}, address = {Graz, Austria},
 year		= 1993}

@article{Axel72,
 author		= {O. Axelsson},
 title		= {A generalized {SSOR} method},
 journal	= BIT,
 volume		= 12, pages = {443--467}, year = 1972}

@book{Axel96,
 author		= {O. Axelsson},
 title		= {Iterative Solution Methods},
 publisher	= CUP, address = CUP-ADDRESS,
 year		= 1996}

%%% B %%%

@inproceedings{BandChenMads88,
 author         = {J. W. Bandler and S. H. Chen and K. Madsen},
 title          = {An algorithm for one-sided $\ell_1$ optimization with 
                   application to circuit design centering},
 booktitle      = {Proceedings 1988 IEEE International Symposium on Circuits 
                   and Systems},
 publisher      = {IEEE}, address = {New York, NY, USA}, 
 volume         = 2, pages = {1795--1798}, year = {1988},
 abstract       = {A highly efficient algorithm for one-sided nonlinear
                   $\ell_1$ optimization combines a trust region
                   Gauss-Newton method and a quasi-Newton method. The
                   proposed method is used as an integral part of an
                   approach to design centering and yield enhancement.},
 summary        = {A highly efficient algorithm for one-sided nonlinear
                   $\ell_1$ optimization combines a trust-region
                   Gauss-Newton method and a quasi-Newton method. The
                   proposed method is used as an integral part of an
                   approach to design centering and yield enhancement.}}

@article{Bann94,
 author		= {T. Bannert},
 title		= {A trust region algorithm for nonsmooth optimization},
 journal	= MP,
 volume		= 67, number = 2, pages = {247--264}, year = 1994,
 abstract	= {A trust region algorithm is proposed for minimizing the
		   nonsmooth composite function $F(x)=h(f(x))$, where $f$ is
		   smooth and $h$ is convex. The algorithm employs a smoothing
		   function, which is closely related to \citebb{Flet70b}'s
		   exact differentiable penalty functions. Global and local
		   convergence results are given, considering convergence to a
		   strongly unique minimizer and to a minimizer satisfying
		   second-order sufficiency conditions.},
 summary	= {A trust-region algorithm is proposed for minimizing the
		   non-smooth composite function $F(x)=h(f(x))$, where $f$ is
		   smooth and $h$ is convex. It uses a smoothing function
		   closely related to \citebb{Flet70b}'s exact differentiable
		   penalty function. Global and local convergence to a
		   strongly unique minimizer and to a minimizer satisfying
		   second-order sufficiency conditions is considered.}}
                  
@article{BakrBandBiemChenMads98,
 author         = {M. H. Bakr and J. W. Bandler and R. M. Biemacki and 
                   S. H. Chen and K. Madsen},
 title          = {A trust region aggressive space mapping algorithm for 
                   {EM} optimization},
 journal 	= {IEEE Transactions on Microwave Theory and Techniques},
 volume 	= 46, number = {12, part~2}, pages = {2412--2425}, year = 1998,
 abstract       = {A new robust algorithm for EM optimization of
                   microwave circuits is presented. The algorithm
                   integrates a trust region methodology with aggressive
                   space mapping (ASM). A new automated multipoint
                   parameter extraction process is implemented. EM
                   optimization of a double-folded stub filter and of an
                   HTS filter illustrate our new results.},
 summary        = {A new robust algorithm for EM optimization of
                   microwave circuits is presented. The algorithm
                   integrates a trust region methodology with aggressive
                   space mapping (ASM). A new automated multipoint
                   parameter extraction process is implemented. EM
                   optimization of a double-folded stub filter and of an
                   HTS filter illustrate our new results.}}

@article{BakrBandGeorMads99,
 author         = {M. H. Bakr and J. W. Bandler and N. Georgieva and K. Madsen},
 title          = {A hybrid aggressive space mapping algorithm for {EM} 
                   optimization},
 journal 	= {IEEE MTT-S International Microwave Symposium Digest},
 volume		= 1, pages = {265--268}, year = 1999,
 abstract	= {We present a novel, hybrid aggressive space mapping (HASM) 
                   optimization algorithm.  HASM is a hybrid approach
                   exploiting both the trust region aggressive space
                   mapping (TRASM) algorithm and direct optimization. It
                   does not assume that the final space-mapped design is
                   the true optimal design and is robust against severe
                   misalignment between the coarse and the fine
                   models. The algorithm is based on a novel lemma that
                   enables smooth switching from the TRASM optimization
                   to direct optimization and vice versa. The new
                   algorithm has been tested on several microwave
                   filters and transformers.},
 summary	= {A hybrid aggressive space mapping (HASM) optimization 
                   method, combining the trust region aggressive space
                   mapping (TRASM) algorithm and direct optimization
                   techiniques, is given. No assumption that the final
                   space-mapped design is the true optimal design is
                   made, and the method is robust against severe
                   misalignment between coarse and fine models. The
                   algorithm is based on theoretical results that enable
                   smooth switching from the TRASM optimization to
                   direct optimization and vice versa. The algorithm is
                   tested on several microwave filters and transformers.}}

@article{BaraSand92,
 author		= {R. Barakat and B. H. Sandler},
 title		= {Determination of the wave-front aberration function from
		   measured values of the point-spread function---A
		   2-dimensional phase retrieval problem},
 journal	= {Journal of the Optical Society of America A-Optics Image
		   Science and Vision},
 volume		= 9, number = 10, pages = {1715--1723}, year = 1992,
 abstract	= {We outline a method for the determination of the unknown
		   wave-front aberration function of an optical system from
		   noisy measurements of the corresponding point-spread
		   function. The problem is cast as a nonlinear unconstrained
		   minimization problem, and trust region techniques are
		   employed for its solution in conjunction with analytic
		   evaluations of the Jacobian and Hessian matrices governing
		   slope and curvature information. Some illustrative
		   numerical results are presented and discussed.},
 summary	= {A method for the determination of the unknown wave-front
		   aberration function of an optical system from noisy
		   measurements of the corresponding point-spread function is
		   considered. The problem is cast as a unconstrained
		   nonlinear minimization problem. Trust-region techniques are
		   employed for its solution, using analytic expressions of
		   the Jacobian and Hessian matrices. Illustrative numerical
		   results are discussed.}}

@article{BarlTora95,
 author		= {J. L. Barlow and G. Toraldo},
 title		= {The effect of diagonal scaling on projected gradient
		   methods for bound constrained quadratic programming
		   problems},
 journal	= OMS,
 volume		= 5, number = 3, pages = {235--245}, year = 1995}

@inproceedings{BartGoluSaun70,
 author    	= {R. H. Bartels and G. H. Golub and M. A. Saunders},
 title     	= {Numerical techniques in mathematical programming},
 crossref  	= {RoseMangRitt70}, pages = {123--176}}

@article{BazaGood82,
 author		= {M. S. Bazaraa and J. J. Goode},
 title		= {Sufficient conditions for a globally exact penalty-function
		   without convexity},
 journal	= MPS,
 volume		= 19, pages = {1--15}, year = 1982}

@incollection{Beal67,
 author		= {E. M. L. Beale},
 title		= {Numerical Methods},
 booktitle	= {Nonlinear programming},
 editor		= {J. Abadie},
 publisher	= NH, address = NH-ADDRESS,
 pages		= {135--205}, year = 1967}

@article{Bell90,
 author		= {B. M. Bell},
 title		= {Global convergence of a semi-infinite optimization method},
 journal	= {Applied Mathematics and Optimization},
 volume		= 21, pages = {69--88}, year = 1990,
 abstract	= {A new algorithm for minimizing locally Lipschitz functions
		   using approximate function values is presented. It yields a
		   method for minimizing semi-infinite exact penalty functions
		   that parallels the trust-region methods used in composite
		   nondifferentiable optimization. A finite method for
		   approximating a semi-infinite exact penalty function is
		   developed. A uniform implicit function theorem is
		   established during this development. An implementation and
		   test results for the approximate penalty function are
		   included.},
 summary	= {An algorithm for minimizing locally Lipschitz functions
		   using approximate function values is presented. It yields a
		   method for minimizing semi-infinite exact penalty functions
		   that parallels the trust-region methods used in composite
		   non-differentiable optimization. A finite method for
		   approximating a semi-infinite exact penalty function is
		   developed. A uniform implicit function theorem is
		   established during this development. An implementation and
		   test results for the approximate penalty function are
		   included.}}

@article{BellRoga95,
 author		= {M. Bellare and P. Rogaway},
 title		= {The complexity of approximating a nonlinear program},
 journal	= MP,
 volume		= 69, number = 3, pages = {429--441}, year = 1995}

@article{BenTTebo96,
 author		= {A. Ben{-}Tal and M. Teboulle},
 title		= {Hidden convexity in some nonconvex quadratically
		   constrained quadratic-programming},
 journal	= MP,
 volume		= 72, number = 1, pages = {51--63}, year = 1996,
 abstract	= {We consider the problem of minimizing an indefinite
		   quadratic objective function subject to two-sided
		   indefinite quadratic constraints. Under a suitable
		   simultaneous diagonalization assumption (which trivially
		   holds for a trust-region type problems), we prove that the
		   original problem is equivalent to a convex minimization
		   problem with simple linear constraints. We then consider a
		   special problem of minimizing a concave quadratic function
		   subject to finitely many convex quadratic constraints,
		   which is also shown to be equivalent to a minimax convex
		   problem. In both cases we derive the explicit nonlinear
		   transformations which allow for recovering the optimal
		   solution of the nonconvex problems via their equivalent
		   convex counterparts. Special cases and applications are
		   also discussed. We outline interior-point polynomial-time
		   algorithms for the solution of the equivalent convex
		   programs.},
 summary	= {The minimization of an indefinite quadratic objective
		   function subject to two-sided indefinite quadratic
		   constraints is considered. Under a simultaneous
		   diagonalization assumption (which trivially holds for a
		   trust-region type problems), it is shown that the original
		   problem is equivalent to a convex minimization problem with
		   simple linear constraints. The special problem of
		   minimizing a concave quadratic function subject to finitely
		   many convex quadratic constraints is then considered and
		   shown to be equivalent to a minmax convex problem. In both
		   cases, the explicit nonlinear transformations which allow
		   the recovery of the optimal solution of the non-convex
		   problems via their equivalent convex counterparts is
		   derived. Interior-point polynomial-time algorithms for the
		   solution of the equivalent convex programs are outlined.}}

@article{BenTZibu97,
 author		= {A. Ben{-}Tal and M. Zibulevsky},
 title		= {Penalty/Barrier Multiplier Methods for Convex Programming
		   Problems},
 journal	= SIOPT,
 volume		= 7, number = 2, pages = {347--366}, year = 1997}

@article{BenTNemi97,
 author		= {A. Ben{-}Tal and A. Nemirovskii},
 title		= {Robust Truss Topology Design via Semidefinite Programming},
 journal	= SIOPT,
 volume		= 7, number = 4, pages = {991--1016}, year = 1997}

@article{BereCler97,
 author		= {Y. Bereaux and J. R. Clermont},
 title		= {Numerical simulation of two- and three-dimensional complex
		   flows of viscoelastic fluids using the stream-tube method},
 journal	= {Mathematics and Computers in Simulation},
 volume		= 44, number = 4, pages = {387--400}, year = 1997,
 abstract	= {The present paper examines the stream-tube method in
		   two-and three-dimensional duct flows. The analysis uses the
		   concept of stream-tubes in a mapped computational domain of
		   the physical domain, where streamlines are parallel and
		   straight. The primary unknown of the problem includes the
		   transformation between the two domains, together with the
		   pressure. Mass conservation is automatically verified by
		   the formulation. Memory-integral constitutive equations may
		   be considered without the particle-tracking problem. The
		   method is applied to flows in contractions and a
		   three-dimensional flow involving a threefold rotational
		   symmetry. Viscous and elastic liquids involving
		   memory-integral equations are investigated in the flow
		   simulations. The discretized schemes for the unknowns are
		   presented and the relevant equations solved by using
		   optimization procedures such as the Levenberg-Marquardt and
		   trust-region methods.},
 summary	= {The stream-tube method in two-and three-dimensional duct
		   flows is analyzed using the concept of stream-tubes in a
		   mapped computational domain of the physical domain, where
		   streamlines are parallel and straight. The primary unknown
		   of the problem includes the transformation between the two
		   domains and the pressure. Mass conservation is
		   automatically verified by the formulation. Memory-integral
		   constitutive equations may be considered without the
		   particle-tracking problem. The method is applied to flows
		   in contractions and a three-dimensional flow involving a
		   threefold rotational symmetry. Viscous and elastic liquids
		   involving memory-integral equations are investigated.. The
		   discretized schemes are presented and the relevant
		   equations solved by using optimization procedures such as
		   the Levenberg-Morrison-Marquardt and trust-region methods.}}

@article{Bert76,
 author		= {D. P. Bertsekas},
 title		= {On the {G}oldstein-{L}evitin-{P}oljak gradient projection
		   method},
 journal	= {IEEE Transactions on Automatic Control},
 volume		= {AC-21}, pages = {174--184}, year = 1976}

@article{Bert82a,
 author		= {D. P. Bertsekas},
 title		= {Projected {N}ewton Methods for Optimization Problems with
		   Simple Constraints},
 journal	= SICON,
 volume		= 20, number = 2, pages = {221--246}, year = 1982}

@book{Bert82b,
 author		= {D. P. Bertsekas},
 title		= {Constrained Optimization and {L}agrange Multiplier Methods},
 publisher	= AP, address = AP-ADDRESS,
 year		= 1982}

@article{Best84,
 author 	= {M. J. Best},
 title  	= {Equivalence of some quadratic-programming algorithms},
 journal 	= MP,
 volume 	= 30, number = 1, pages = {71--87}, year = 1984}

@article{BestChak90,
 author		= {M. J. Best and N. Chakravarti},
 title		= {Active set algorithms for isotonic regression; a unifying
		   framework},
 journal	= MP,
 volume		= 47, pages = {425--439}, year = 1990}

@techreport{BestRitt76,
 author  	= {M. J. Best and K. Ritter},
 title   	= {An effective algorithm for quadratic minimization problems},
 institution 	= {University of Wisconsin},
 address 	= {Madison, Wisconsin, U.S.A.},
 type    	= {Technical report}, number = 1691, year = 1976}

@article{BiegNoceSchm95,
 author		= {L. T. Biegler and J. Nocedal and C. Schmid},
 title		= {A Reduced {H}essian Method for Large-Scale Constrained
		   Optimization},
 journal	= SIOPT,
 volume		= 5, number = 2, pages = {314--347}, year = 1995}

@misc{BielGome98,
 author		= {R. H. Bielschowsky and F. A. M. Gomes},
 title		= {Dynamical Control of Infeasibility in Nonlinearly
		   Constrained Optimization},
 howpublished	= {Presentation at the Optimization 98 Conference, Coimbra},
 year		= 1998,
 abstract	= {We present a new algorithm for nonconvex nonlinear
		   programming problems with equality constraints in the form
		   $\min f(x)$ subject to $h(x)=0$. The algorithm keeps some
		   characteristics of feasible point methods, but is concerned
		   with flexibilizing the equality restrictions. Essentially,
		   the idea is to avoid both forcing the iterates to stay too
		   near the feasible set and using a merit function. Each
		   major iteration of the algorithm is divided in two phases.
		   In the first, we seek a vertical step $d_v$ such that the
		   infeasibility $x_c=x_k+d_v$ stays controlled, in the sense
		   that $x_c$ satisfies $\|h(x_c)\|=O(\|g_p(x_c)\|)$, where
		   $g_p(x_c)$ is the orthogonal projection of $\nabla f(x_c)$
		   in the tangent space to the restrictions. Frequently, $x_k$
		   satisfies this condition, so we can make $x_c=x_k$. The aim
		   of the second phase is to find a horizontal step $d_h$ that
		   reduces the Lagrangian and stays approximately tangent to
		   the constraints. This is done by confining $x_c+d_h$ to a
		   cylinder with radius $r=O(\|g_p(x_c)\|)$ around $h(x)=0$.
		   The new algorithm is well-suited for large-scale problems.
		   Implementation details, as well as some preliminary
		   numerical results based on problems from the CUTE
		   collection, are presented. We also prove global convergence
		   results.},
 summary	= {An algorithm is presented for solving non-convex
		   problems of the form $\min f(x)$
		   subject to $h(x)=0$. At each major iteration, one
		   first seeks a normal step $d_v$ such that $x_c$ satisfies
		   $\|h(x_c)\|=O(\|g_p(x_c)\|)$, where $g_p(x_c)$ is the
		   orthogonal projection of $\nabla f(x_c)$ on the tangent
		   space. A tangential step $d_h$ is then computed that
		   reduces the Lagrangian and stays approximately tangent to
		   the constraints. This is done by confining $x_c+d_h$ to a
		   cylinder with radius $r=O(\|g_p(x_c)\|)$ around $h(x)=0$.
		   Implementation details, as well as preliminary numerical
		   results on problems from the {\sf CUTE} collection, are
		   presented. Global convergence results are also proved.}}

@article{Bier94,
 author		= {M. Bierlaire},
 title		= {{HieLoW}: un logiciel d'estimation de mod\`eles Logit
		   embo\^\i t\'es},
 journal	= {Cahiers du MET},
 volume		= 2, pages = {29--43}, month = {Novembre}, year = 1994}

@techreport{Bier95a,
 author		= {M. Bierlaire},
 title		= {A robust algorithm for the simultaneous estimation of
		   hierarchical logit models},
 institution	= FUNDP, address = FUNDP-ADDRESS,
 type		= {GRT Report}, number = {95/3}, year = 1995,
 abstract	= {Estimating simultaneous hierarchical logit models is
		   conditional to the availability of suitable algorithms.
		   Powerful mathematical programs are necessary to maximize
		   the associated non-linear, non-convex, log-likelihood
		   function. Even if classical methods (e.g. Newton-Raphson)
		   can be adapted for relatively simple cases, the need of an
		   efficient and robust algorithm is justified to enable
		   practioners to consider a wider class of models. The
		   purpose of this paper is to analyze and to adapt to this
		   context methodologies available in the optimization
		   literature. An algorithm is proposed based on two major
		   concepts from non-linear programming : \emph{a trust-region
		   method}, that ensures robustness and global convergence,
		   and \emph{a conjugate gradients iteration}, that can be used
		   to solve the quadratic subproblems arising in the
		   estimation process described in this paper. Numerical
		   experiments are finally presented that indicate the power
		   of the proposed algorithm and associated software.},
 summary	= {A trust-region method is proposed for the estimation of
		   simultaneous hierarchical logit models, where the
		   subproblem is solved by a truncated conjugate-gradients
		   technique. Numerical experiments indicate the power of the
		   proposed algorithm and associated software.}}

@inproceedings{Bier98,
 author         = {M. Bierlaire},
 title          = {Discrete Choice Models},
 crossref       = {LabbLapoTancToin98}, pages = {203--227}}

@article{BierToin95,
 author		= {M. Bierlaire and Ph. L. Toint},
 title		= {{MEUSE}: an Origin-Destination Estimator That Exploits
		   Structure},
 journal	= {Transportation Research B},
 volume		= 29, number = 1, pages = {47--60}, year = 1995}

@article{BierToinTuyt91,
 author		= {M. Bierlaire and Ph. L. Toint and D. Tuyttens},
 title		= {On iterative algorithms for linear least squares problems
		   with bound constraints},
 journal	= LAA,
 volume		= 143, pages = {111--143}, year = 1991,
 abstract	= {Three new iterative methods for the solution of the linear
		   least squares problem with bound constraints are presented
		   and their performance analyzed. The first is a modification
		   of a method proposed by \citebb{Lots84}, while the two
		   others are characterized by a technique allowing for fast
		   active set changes, resulting in noticeable improvements in
		   the speed with which constraints active at the solution are
		   identified. The numerical efficiency of these algorithms is
		   studied, with particular emphasis on the dependence on the
		   starting point and the use of preconditioning for
		   ill-conditioned problems.},
 summary	= {Three iterative methods for the solution of the linear
		   least-squares problem with bound constraints are presented
		   and their performance analyzed. The first is a modification
		   of a method proposed by \citebb{Lots84}, while the others
		   two allow fast active set changes. The numerical efficiency
		   of these algorithms is studied.}}

@inproceedings{Bigg72,
 author		= {M. C. Biggs},
 title		= {Constrained Minimization Using Recursive Equality Quadratic
		   Programming},
 crossref	= {Loot72}, pages = {411--428}}

@article{Bigg87,
 author		= {M. C. Bartholomew{-}Biggs},
 title		= {Recursive quadratic-programming methods based on the
		   augmented {L}agrangian},
 journal	= MPS,
 volume		= 31, pages = {21--41}, year = 1987}

@article{BillFerr97,
 author		= {S. C. Billups and M. C. Ferris},
 title		= {{QPCOMP}: A Quadratic Program Based Solver for Mixed
		   Complementarity Problems},
 journal	= MP,
 volume		= 76, number = 3, pages = {533--562}, year = 1997}

@book{Bjor96,
 author		= {{\AA}. Bj{\"o}rck},
 title		= {Numerical Methods for Least Squares Problems},
 publisher	= SIAM, address = SIAM-ADDRESS,
 year		= 1996}

@article{Bock96,
 author		= {C. Bockmann},
 title		= {Curve-fitting and identification of physical spectra},
 journal	= JCAM,
 volume		= 70, number = 2, pages = {207--224}, year = 1996,
 abstract	= {A modification of the trust-region Gauss-Newton method for
		   the identification of physical spectra is described and
		   analysed. Local convergence results are presented.},
 summary	= {A modification of the trust-region Gauss-Newton method for
		   the identification of physical spectra is described and
		   analysed. Local convergence results are presented.}}

@inproceedings{BockSchlSchu95,
 author		= {H. G. Bock and J. P. Schl\"{o}der and V. H. Schulz},
 title		= {Numerik gro\ss er {D}ifferentiell-{A}lgebraischer
		   {G}leichungen---{S}imulation und {O}ptimierung},
 booktitle	= {Proce\ss simulation},
 editor		= {H. Schuler},
 publisher	= {VCH Verlaggesellschaft}, address = {Weinheim, Germany},
 pages		= {35--80}, year = 1995}

@article{Bofi95,
 author		= {J. M. Bofill},
 title		= {A Conjugate-Gradient Algorithm with a Trust Region for
		   Molecular-Geometry Optimization},
 journal	= {Journal of Molecular Modeling},
 volume		= 1, number = 1, pages = {11--17}, year = 1995,
 abstract	= {An algorithm is presented for the optimization of molecular
		   geometries and general non-quadratic functions using the
		   nonlinear conjugate gradient method with a restricted step
		   and a restart procedure. The algorithm only requires the
		   evaluation of the energy function and its gradient and less
		   memory storage is needed than for other conjugate gradient
		   algorithms. Some numerical results are also presented and
		   the efficiency and behaviour of the algorithm is compared
		   with the standard conjugate gradient method. On the other
		   hand we present comparisons of both conjugate gradient and
		   variable metric methods with and without the trust-region
		   technique. One of the main conclusions of the present work
		   is that a trust region always improves the convergence of
		   an optimization method. A sketch of the algorithm is also
		   given.},
 summary	= {An algorithm is presented for the optimization of molecular
		   geometries and general functions using the
		   nonlinear conjugate-gradient method with a restricted step
		   and a restart procedure. The algorithm requires less
		   memory storage than other conjugate-gradient
		   algorithms. Numerical results are presented, and the
		   efficiency of the algorithm is compared with the standard
		   conjugate-gradient method. A comparison of both
		   conjugate-gradient and variable-metric methods with and
		   without the trust-region technique is made. It is concluded
		   that a trust region always improves the convergence.
		   A sketch of the algorithm is given.}}

@article{BoggByrdSchn87,
 author		= {P. T. Boggs and R. H. Byrd and R. B. Schnabel},
 title		= {A stable and efficient algorithm for nonlinear orthogonal
		   distance regression},
 journal	= SISSC,
 volume		= 8, number = 6, pages = {1052--1078}, year = 1987,
 abstract	= {One of the most widely used methodologies in scientific and
		   engineering research is the fitting of equations to data by
		   least squares. In cases where significant observation
		   errors exist in the independent variables as well as the
		   dependent variables, however, the ordinary least squares
		   (OLS) approach, where all the error are attributed to the
		   dependent variable, is often inappropriate. An alternate
		   approach, suggested by several researchers, involves
		   minimizing the sum of squared orthogonal distances between
		   each data point and the curve described by the model
		   equation. We refer to this as orthogonal distance
		   regression (ODR). This paper describes a method for solving
		   the orthogonal distance regression problem that is a direct
		   analog of the trust region Levenberg-Marquardt algorithm.
		   The number of unknowns involved is the number of model
		   parameters plus the number of data points, often a very
		   large number. By exploiting sparsity, however, our
		   algorithm has a computational effort per step which is of
		   the same order as required for the Levenberg-Marquardt
		   method for ordinary least squares. We prove our algorithm
		   to be globally and locally convergent, and perform
		   computational tests that illustrate some differences
		   between ODR and OLS.},
 summary	= {A method for solving the orthogonal distance regression
		   problem is described that is an analog of the trust-region
		   Levenberg-Morrison-Marquardt algorithm. The number of
		   unknowns involved is the number of model parameters plus
		   the number of data points, often a very large number. By
		   exploiting sparsity, the computational effort per step is
		   of the same order as that required for the
		   Levenberg-Morrison-Marquardt method for ordinary
		   least-squares. The algorithm is proved to be globally and
		   locally convergent. Computational tests 
		   illustrate differences between orthogonal distance
		   regression and ordinary least-squares.}}

@article{BoggDonaByrdSchn89,
 author		= {P. T. Boggs and J. R. Donaldson and R. H. Byrd and R. B.
		   Schnabel},
 title		= {{ORDPACK} software for weighted orthogonal distance
		   regression},
 journal	= TOMS,
 volume		= 15, number = 4, pages = {348--364}, year = 1989,
 abstract	= {In this paper, we describe ORDPACK, a software package for
		   the weighted orthogonal distance regression problem. This
		   software is an implementation of the algorithm described in
		   \citebb{BoggByrdSchn87} for finding the parameters that
		   minimize the sum of the squared weighted orthogonal
		   distances from a set of observations to a curve or surface
		   determined by the parameters. It can also be used to solve
		   the ordinary nonlinear least squares problem. The weighted
		   orthogonal distance regression procedure implemented is an
		   efficient and stable trust region (Levenberg-Marquardt)
		   procedure that exploits the structure of the problem so
		   that the computational cost per iteration is equal to that
		   for the same type of algorithm applied to the ordinary
		   least squares problem. The package allows a general
		   weighting scheme, provides for finite difference
		   derivatives, and contains extensive error checking and
		   report generating facilities.},
 summary	= {ORDPACK, a software package for the weighted orthogonal
		   distance regression problem is described. This software is
		   an implementation of the algorithm described in
		   \citebb{BoggByrdSchn87} for finding the parameters that
		   minimize the sum of the squared weighted orthogonal
		   distances from a set of observations to a curve or surface
		   determined by the parameters. It can also be used to solve
		   the ordinary nonlinear least-squares problem. The package
		   allows a general weighting scheme, provides for finite
		   difference derivatives, and contains extensive error
		   checking and report generating facilities.}}

@techreport{BoggDomiRoge95,
 author  	= {P. T. Boggs and P. D. Domich and J. E. Rogers},
 title   	= {An interior point method for general large-scale quadratic
            	   programming problems},
 institution 	= NIST, address = NIST-ADDRESS,
 type    	= {Internal report}, number = {NISTIR 5406}, year = 1995}

@article{BoggToll89,
 author		= {P. T. Boggs and J. W. Tolle},
 title		= {A strategy for global convergence in a sequential quadratic
		   programming algorithm},
 journal	= SINUM,
 volume		= 26, number = 3, pages = {600-623}, year = 1989}

@article{BoggToll95,
 author 	= {P. T. Boggs and J. W. Tolle},
 title  	= {Sequential quadratic programming},
 journal 	= {Acta Numerica},
 volume 	= 4, pages = {1--51}, year = 1995}


@techreport{BoggTollKear91,
 author		= {P. T. Boggs and J. W. Tolle and A. J. Kearsley},
 title		= {A merit function for inequality constrained nonlinear
		   programming problems},
 institution	= NIST, address = NIST-ADDRESS,
 type		= {Internal report}, number = {NISTIR 4702}, year = 1991}

@techreport{BoggTollKear94,
 author		= {P. T. Boggs and J. W. Tolle and A. J. Kearsley},
 title		= {A practical algorithm for general large scale nonlinear
		   optimization problems},
 institution	= NIST, address = NIST-ADDRESS,
 type		= {Internal report}, number = {NISTIR 5407}, year = 1994}

@article{BoggKearToll99,
 author         = {P. T. Boggs and A. J. Kearsley and J. W. Tolle},
 title          = {A Practical Algorithm for General Large Scale Nonlinear 
                   Optimization Problems},
 journal        = SIOPT,
 volume         = 9, number = 3, pages = {755--778}, year = 1999,
 abstract	= {We provide an effective and efficient implementation of 
                   a sequential quadratic programming (SQP) algorithm
                   for the general large scale nonlinear programming
                   problem. In this algorithm the quadratic programming
                   subproblems are solved by an interior point method
                   that can be prematurely halted by a trust region
                   constraint. Numerous computational enhancements to
                   improve the numerical performance are
                   presented. These include a dynamic procedure for
                   adjusting the merit function parameter and procedures
                   for adjusting the trust region radius. Numerical
                   results and comparisons are presented. },
 summary	= {An effective and efficient implementation of 
                   a sequential quadratic programming (SQP) algorithm
                   for the general large scale nonlinear programming
                   problem is given. The quadratic programming
                   subproblems are solved by an interior point method, and
                   can be prematurely halted by a trust region
                   constraint. Numerous computational enhancements to
                   improve the numerical performance are
                   presented. These include a dynamic procedure for
                   adjusting the merit function parameter and procedures
                   for adjusting the trust region radius. Numerical
                   results and comparisons are presented.}}

@article{BongConnGoulToin95,
 author		= {I. Bongartz and A. R. Conn and N. I. M. Gould and Ph. L.
		   Toint},
 title		= {{\sf CUTE}: {C}onstrained and {U}nconstrained {T}esting
		   {E}nvironment},
 journal	= TOMS,
 volume		= 21, number = 1, pages = {123--160}, year = 1995}
%abstract       = {The purpose of this paper is to discuss the scope and
%                  functionality of a versatile environment for testing small
%                  and large-scale nonlinear optimization algorithms.
%                  Although many of these facilities were originally produced
%                  by the authors in conjunction with the software package
%                  {\sf LANCELOT}, we believe that they will be useful in
%                  their own right and should be available to researchers for
%                  their development of optimization software. The tools are
%                  available by anonymous ftp from a number of sources and
%                  may, in many cases, be installed automatically. The scope
%                  of a major collection of test problems written in the
%                  standard input format (SIF) used by the {\sf LANCELOT}
%                  software package is described. Recognising that most
%                  software was not written with the SIF in mind, we provide
%                  tools to assist in building an interface between this
%                  input format and other optimization packages. These tools
%                  already provide a link between the SIF and an number of
%                  existing packages, including MINOS and OSL. In addition,
%                  as each problem includes a specific classification that is
%                  designed to be useful in identifying particular classes of
%                  problems, facilities are provided to build and manage a
%                  database of this information. There is a UNIX and C-shell
%                  bias to many of the descriptions in the paper, since, for
%                  the sake of simplicity, we do not illustrate everything in
%                  its fullest generality. We trust that the majority of
%                  potential users are sufficiently familar with UNIX that
%                  these examples will not lead to undue confusion.}}

@article{BonnBouh95,
 author		= {J. F. Bonnans and M. Bouhtou},
 title		= {The trust region affine interior-point algorithm for convex
		   and nonconvex quadratic-programming},
 journal	= RAIRO-OR,
 volume		= 29, number = 2, pages = {195--217}, year = 1995,
 abstract	= {We study from a theoretical and numerical point of view an
		   interior point algorithm for quadratic QP using a trust
		   region idea, formulated by \citebb{YeTse89}. We show that,
		   under a nondegeneracy hypothesis the algorithm converges
		   globally in the convex case. For a nonconvex problem, under
		   a mild additional hypothesis, the sequence of points
		   converges to a stationary point. We obtain also an
		   asymptotic linear convergence rate for the cost that
		   depends only on the dimension of the problem. Then we show
		   that, provided some modifications are added to the basic
		   algorithm, the method has a good numerical behaviour.},
 summary	= {A theoretical and numerical investigation of an interior
		   point algorithm for quadratic programming using a
		   trust-region scheme formulated by \citebb{YeTse89} is
		   performed. Under a non-degeneracy hypothesis, the algorithm
		   converges globally in the convex case. For a non-convex
		   problem, the sequence of points converges to a stationary
		   point under a mild additional assumption. An asymptotic
		   linear convergence factor that depends only on the
		   dimension of the problem is given. Provided simple
		   modifications are made, the method behaves numerically
		   well.}}

@article{BonnGilbLemaSaga95,
 author		= {J. F. Bonnans and J. Ch. Gilbert and C. Lemar\'{e}chal and
		   C. A. Sagastiz\'{a}bal},
 title		= {A family of variable metric proximal methods},
 journal	= MPA,
 volume		= 68, number = 1, pages = {15--47}, year = 1995}

@techreport{BonnLaun92,
 author         = {J. F. Bonnans and G. Launay},
 title          = {Implicit trust region algorithm for constrained 
                   optimization},
 institution	= {Institute Nationale Recherche Informatique et Automation}, 
 address        = {Le Chesnay, France},
 year           = 1992,
 abstract       = {The authors study the convergence of sequential
                   quadratic programming algorithms for the nonlinear
                   programming problems. Assuming only that the
                   direction is a stationary point of the current
                   quadratic program they study the local convergence
                   properties without strict complementarity. They
                   obtain some global and superlinearly convergent
                   algorithms. As a particular case they formulate an
                   extension of Newton's method that is quadratically
                   convergent to a point satisfying a strong sufficient
                   second order condition.},
 summary        = {Convergence of sequential
                   quadratic programming algorithms for the nonlinear
                   programming problems is studied without assuming strict
		   complementarity and global and superlinearly convergence
		   results are obtained.}}

@article{BonnLaun95,
 author		= {J. F. Bonnans and G. Launay},
 title		= {Sequential Quadratic-Programming with Penalization of the
		   Displacement},
 journal	= SIOPT,
 volume		= 5, number = 4, pages = {792--812}, year = 1995,
 abstract	= {In this paper, we study the convergence of a sequential
		   quadratic programming algorithm for the nonlinear
		   programming problem. The Hessian of the quadratic program
		   is the sum of an approximation of the Lagrangian and of a
		   multiple of the identity that allows us to penalize the
		   displacement. Assuming only that direction is a stationary
		   point of the current quadratic program we study the local
		   convergence properties without strict complementarity. In
		   particular, we use a very weak condition on the
		   approximation of the Hessian to the Lagrangian. We obtain
		   some global and superlinearly convergent algorithm under
		   weak hypotheses. As a particular case we formulate an
		   extension of Newton's method that is quadratically
		   convergent to a point satisfying a strong sufficient
		   second-order condition.},
 summary	= {The convergence of an SQP algorithm for nonlinear
		   programming is considered. The Hessian of the QP is the sum
		   of an approximation of the Lagrangian and of a multiple of
		   the identity that penalizes the displacement. Assuming only
		   that direction is a stationary point for the current QP,
		   the algorithm is globally and superlinearly convergent
		   without strict complementarity. As a particular case, an
		   extension of Newton's method is given that is quadratically
		   convergent to a point satisfying a strong sufficient
		   second-order condition.}}

@article{BonnPaniTitsZhou92,
 author		= {J. F. Bonnans and E. Panier and A. L. Tits and J. L. Zhou},
 title		= {Avoiding the {M}aratos effect by means of a nonmonotone
		   linesearch {II}. Inequality constrained problems---feasible
		   iterates},
 journal	= SINUM,
 volume		= 29, pages = {1187--1202}, year = 1992,
 abstract	= {When solving inequality constrained optimization problems
		   via Sequential Quadratic Programming (SQP), it is
		   potentially advantageous to generate iterates that all
		   satisfy the constraints: all quadratic programs encountered
		   are then feasible and there is no need for a surrogate
		   merit function. (Feasibility of the successive iterates is
		   in fact required in many contexts such as in real-time
		   applications or when the objective function is not defined
		   outside the feasible set.) It has recently been shown that
		   this, indeed, possible, by means of a suitable perturbation
		   of the original SQP iteration, without loosing superlinear
		   convergence. In this context, the well-known
		   \citebb{Mara78} effect is coumpounded by the possible
		   infeasibility of the full step of one even close to the
		   solution. These difficulties have been accomodated by
		   making use of a suitable modification of a "bending"
		   technique proposed by \citebb{MaynPola82}, requiring
		   evaluation of the constraints function at an auxiliary
		   point at each iteration. In Part I of this two-part paper,
		   it was shown that, when feasibility of the successive
		   iterates is not required, the Maratos effect can be avoided
		   by combining Mayne and Polyak's technique with a
		   non-monotone line serach proposed by
		   \citebb{GripLampLuci86} in the context of unconstrained
		   optimization in such a way that, except possibly at a few
		   early iterations, function evaluations are no longer
		   performed at auxiliary points. In this second part, it is
		   shown that feasibility can be restored without resorting to
		   additional constraint evaluations, by adaptively estimating
		   a bound on the second derivatives of the active
		   constraints. Extension to constrained minimax problems is
		   briefly discussed.},
 summary	= {When solving inequality constrained optimization problems
		   via SQP, it may be advantageous to generate iterates that
		   always satisfy the constraints. In this context, the
		   Maratos effect is compounded by the possible
		   infeasibility of a unit step even close to the solution. It
		   is shown that feasibility can be restored without resorting
		   to additional constraint evaluations, by adaptively
		   estimating a bound on the second derivatives of the active
		   constraints. The extension to constrained minimax problems
		   is briefly discussed.}}

@article{BonnPola97,
 author		= {J. F. Bonnans and C. Pola},
 title		= {A Trust Region Interior Point Algorithm for Linearly
		   Constrained Optimization},
 journal	= SIOPT,
 volume		= 7, number = 3, pages = {717--731}, year = 1997,
 abstract	= {We present an extension for nonlinear optimization under
		   linear constraints of an algorithm for quadratic
		   programming using a trust region idea, introduced by
		   \citebb{YeTse89} and extended by \citebb{BonnBouh95}. Due
		   to the nonlinearity of the cost function, we use a
		   linesearch in order to reduce the step if necessary. We
		   prove that, under suitable hypotheses, the algorithm
		   converges to a point satisfying the first-order optimality
		   system, and we analyse under which conditions the unit
		   stepsize will asymptotically be accepted.},
 summary	= {An extension of the trust-region quadratic programming
		   algorithm of \citebb{YeTse89} and \citebb{BonnBouh95} to
		   nonlinear optimization subject to linear constraints is
		   given. A linesearch is used to reduce the step if
		   necessary. Under suitable hypotheses, the algorithm
		   converges to a first-order stationary point. Conditions
		   under which the unit stepsize is asymptotically accepted
		   are analysed.}}

@article{BookDennFranSeraTorcTros99,
 author		= {A. J. Booker and J. E. Dennis and P. D. Frank and D. B.
		   Serafini and V. Torczon and M. W. Trosset},
 title		= {A Rigorous Framework for Optimization of Expensive
		   Functions by Surrogates},
 journal	= {Structural Optimization},
 volume         = 17, number = 1, pages = {1--13}, year = 1999}
% abstract	= {The goal of the research reported on here is to develop
%		   rigourous optimization algorithms to apply to some
%		   engineering design problems for which direct application
%		   of traditional optimization approaches is not practical.
%		   This paper presents and analyzes a framework for
%		   generating and managing a sequence of surrogate objective
%		   functions to obtain convergence to a minimizer of an
%		   expensive objective function subject to simple constraints.
%  		   The approach is widely applicable because it does not
%		   require, or even approximate, derivatives of the objective.
%		   Numerical results are presented for a 31-variable
%		   helicopter rotor design example and for a standard
%		   optimization test example.  This is a brief description
%		   of a portion of the Boeing/IBM/Rice University
%		   collaboration, whose purpose is to develop effective
%		   numerical methods for managing the use of approximation
%		   concepts in design optimization.},
% abstract	= {A framework is presented for generating and managing a
%		   sequence of surrogate objective functions to obtain
%		   convergence to a minimizer of an expensive objective
%		   function subject to simple constraints.  The approach is
%		   widely applicable because it does not require, or even
%		   approximate, derivatives of the objective.  This is
%		   especially useful in the context of engineering design
%		   problems for which direct application of traditional
%		   optimization approaches is not practical.  Numerical
%		   results are presented for a 31-variable helicopter
%		   rotor design example and for a standard optimization
%		   test example.}}

@book{Boot64, 
 author 	= {J. C. Boot},
 title   	= {Quadratic Programming},
 publisher 	= NH, address = NH-ADDRESS,
 year    	= 1964}

@phdthesis{Borg94,
 author		= {J. Borggaard},
 title		= {The sensitivity equation method for optimal design},
 school		= {Department of Mathematics, Virginia Polytechnic Institute
		   and State University},
 address	= {Blackburg, Virginia, USA},
 year		= 1994}

@inproceedings{BorgBurn94,
 author		= {J. Borggaard and J. Burns},
 title		= {A sensitivity equation approach to shape optimization in
		   fluid flows},
 booktitle	= {Proceedings of the IMA Period of Concentration on Flow
		   Control},
 editor		= {M. Gunzburger},
 publisher	= SPRINGER, address = SPRINGER-ADDRESS,
 pages		= {49--78}, year = 1997,
 abstract	= {In this paper we apply a sensitivity equation method to
		   shape optimization problems. An algorithm is developed and
		   tested on a problem of designing optimal forebody
		   simulators for a 2D, inviscid supersonic flow. The
		   algorithm uses a BFGS/Trust Region optimization scheme with
		   sensitivities computed by numerically approximating the
		   linear partial differential equations that determine the
		   flow sensitivities. Numerical examples are presented to
		   illustrate the method.},
 summary	= {A sensitivity equation method is applied to shape
		   optimization problems. An algorithm is developed and tested
		   on a problem of designing optimal forebody simulators for a
		   2D, inviscid supersonic flow. The algorithm uses a
		   BFGS/trust-region optimization scheme, with sensitivities
		   computed by numerically approximating the linear partial
		   differential equations that determine the flow
		   sensitivities. Numerical examples are presented.}}

@article{BorgBurn97,
 author		= {J. Borggaard and J. Burns},
 title		= {A {PDE} sensitivity equation method for optimal aerodynamic
		   design},
 journal	= {Journal of Computational Physics},
 volume		= 136, number = 2, pages = {366--384}, year = 1997,
 abstract	= {The use of gradient based optimization algorithms in
		   inverse design is well established as a practical approach
		   to aerodynamic design. A typical procedure uses a
		   simulation scheme to evaluate the objective function (from
		   the approximate states) and its gradient, then passes this
		   information to an optimization algorithm. Once the
		   simulation scheme (CFD flow solver) has been selected and
		   used to provide approximate function evaluations, there are
		   several possible approaches to the problem of computing
		   gradients. One popular method is to differentiate the
		   simulation scheme and compute design sensitivities that are
		   then used to obtain gradients. Although this black-box
		   approach has many advantages in shape optimization
		   problems, one must compute mesh sensitivities in order to
		   compute the design sensitivity. In this paper, we present
		   an alternative approach using the PDE sensitivity equation
		   to develop algorithms for computing gradients. This
		   approach has the advantage that mesh sensitivities need not
		   be computed. Moreover, when it is possible to use the CFD
		   scheme for both the forward problem and the sensitivity
		   equation, then there are computational advantages. An
		   apparent disadvantage of this approach is that it does not
		   always produce consistent derivatives. However, for a
		   proper combination of discretization schemes, one can show
		   asymptotic consistency under mesh refinement, which is
		   often sufficient to guarantee convergence of the optimal
		   design algorithm. In particular, we show that when
		   asymptotically consistent schemes are combined with a
		   trust-region optimization algorithm, the resulting optimal
		   design method converges. We denote this approach as the
		   sensitivity equation method. The sensitivity equation
		   method is presented, convergence results are given and the
		   approach is illustrated on two optimal design problems
		   involving shocks.},
 summary	= {An approach using the PDE sensitivity equation to develop
		   algorithms for computing gradients in inverse design
		   problems is considered, in which
		   that mesh sensitivities need not be computed. Moreover, it is
		   advantageous when possible to use the CFD scheme for both
		   the forward problem and the sensitivity equation. For a
		   proper combination of discretization schemes, asymptotic
		   consistency under mesh refinement is shown, which is often
		   sufficient to guarantee convergence of the optimal design
		   algorithm. In particular, when asymptotically consistent
		   schemes are combined with a trust-region optimization
		   algorithm, the resulting optimal design method converges.
		   Such a method is described, convergence results are given,
		   and the approach is illustrated on two optimal design
		   problems involving shocks.}}

@article{Borw82,
 author		= {J. M. Borwein},
 title		= {Necessary and sufficient conditions for quadratic
		   minimality},
 journal	= {Numerical Functional Analysis and Optimization},
 volume		= 5, pages = {127--140}, year = 1982}

@article{Boua97,
 author		= {A. Bouaricha},
 title		= {Algorithm 765: {STENMIN}: a software package for large,
		   sparse unconstrained optimization using tensor methods},
 journal	= TOMS,
 volume		= 23, number = 1, pages = {81--90}, year = 1997,
 abstract	= {We describe a new package for minimizing an unconstrained
		   nonlinear function where the Hessian is large and sparse.
		   The software allows the user to select between a tensor
		   method and a standard method based upon a quadratic model.
		   The tensor method models the objective function by a
		   fourth-order model, where the third- and fourth-order terms
		   are chosen such that the extra cost of forming and solving
		   the model is small. The new contribution of this package
		   consists of the incorporation of an entirely new way of
		   minimizing the tensor model that makes it suitable for
		   solving large, sparse optimization problems efficiently.
		   The test results indicate that, in general, the tensor
		   method is often more efficient and more reliable than the
		   standard Newton method for solving large, sparse
		   unconstrained optimization problems.},
 summary	= {A package is presented for minimizing an unconstrained
		   nonlinear function where the Hessian is large and sparse.
		   The software allows the user to select between a tensor
		   method and a standard method based upon a quadratic model.
		   The tensor method models the objective function by a
		   fourth-order model, where the third- and fourth-order terms
		   are chosen such that the extra cost of forming and solving
		   the model is small. The contribution consists of the
		   incorporation of a new way of minimizing the tensor model
		   that is suitable for solving large, sparse problems. The
		   test results indicate that the tensor method is often more
		   efficient and more reliable than the standard Newton
		   method.}}

@article{BouaSchn97,
 author		= {A. Bouaricha and R. B. Schnabel},
 title		= {Algorithm 768: {TENSOLVE}: a software package for
		   solving systems of nonlinear equations and nonlinear
		   least-squares problems using tensor methods},
 journal	= TOMS,
 volume		= 23, number = 2, pages = {174--195}, year = 1997,
 abstract	= {This article describes a modular software package for
		   solving systems of nonlinear equations and nonlinear
		   least-squares problems, using a new class of methods called
		   tensor methods. It is intended for small- to medium-sized
		   problems, say with up to 100 equations and unknowns, in
		   cases where it is reasonable to calculate the Jacobian
		   matrix or to approximate it by finite differences at each
		   iteration. The software allows the user to choose between a
		   tensor method and a standard method based on a linear
		   model. The tensor method approximates $F(x)$ by a quadratic
		   model, where the second-order term is chosen so that the
		   model is hardly more expensive to form, store, or solve
		   than the standard linear model. Moreover, the software
		   provides two different global strategies: a line search
		   approach and a two-dimensional trust region approach. Test
		   results indicate that, in general, tensor methods are
		   significantly more efficient and robust than standard
		   methods on small-and medium-sized problems in iterations
		   and function evaluations.},
 summary	= {A modular software package for solving systems of nonlinear
		   equations and nonlinear least-squares problems, using
		   tensor methods, is described. It is intended for
		   small- to medium-sized problems for which it is
		   reasonable to calculate the Jacobian or to
		   approximate it by finite differences at each iteration. It
		   allows the user to choose between a tensor method
		   and a standard method based on a linear model. The tensor
		   method approximates $F(x)$ by a quadratic model, where the
		   second-order term is chosen so that the model is hardly
		   more expensive to form, store, or solve than the
		   linear model. The software provides both a linesearch and a
		   two-dimensional trust-region approach. Test results
		   indicate that tensor methods are significantly more
		   efficient and robust than standard methods on small-and
		   medium-sized problems in iterations and function
		   evaluations.}}

@article{BouaSchn98,
 author		= {A. Bouaricha and R. B. Schnabel},
 title		= {Tensor methods for large sparse systems of nonlinear
		   equations},
 journal	= MP,
 volume		= 82, number = 3, pages = {377--412}, year = 1998,
 abstract	= {This paper introduces tensor methods for solving large
		   sparse systems of nonlinear equations. Tensor methods for
		   nonlinear equations were developed in the context of
		   solving small to medium-sized dense problems. They base
		   each iteration on a quadratic model of the nonlinear
		   equations, where the second-order term is selected so that
		   the model requires no more derivative or function
		   information per iteration than standard linear model-based
		   methods, and hardly more storage or arithmetic operations
		   per iteration. Computational experiments on small to
		   medium-sized problems have shown tensor methods to be
		   considerably more efficient than standard Newton based
		   methods, with a particularly large advantage on singular
		   problems. This paper considers the extension of this
		   approach to solve large sparse problems. The key issue
		   considered is how to make efficient use of sparsity in
		   forming and solving the tensor model problem at each
		   iteration. Accomplishing this turns out to require an
		   entirely new way of solving the tensor model that
		   successfully exploits the sparsity of the Jacobian, whether
		   the Jacobian is nonsingular or singular. We develop such an
		   approach and, based upon it, an efficient tensor method for
		   solving large sparse systems of nonlinear equations. Test
		   results indicate that this tensor method is significantly
		   more efficient and robust than an efficient sparse
		   Newton-based method, in terms of iterations, function
		   evaluations, and execution time.},
 summary	= {This paper considers the extension of the tensor approach
		   proposed in \citebb{BouaSchn97}. This requires a new way of
		   solving the tensor model that exploits the sparsity of the
		   Jacobian, whether singular or not.}}

@article{BouaSchn99,
 author		= {A. Bouaricha and R. B. Schnabel},
 title		= {Tensor methods for large sparse nonlinear
		   least-squares},
 journal	= SISC,
 volume		= 21, number = 4, pages = {1199--1221}, year = 1999}


@book{BoydElGhFeroBala94,
 author		= {S. Boyd and L. El{-}Ghaoui and E. Feron and V. Balakrishnan},
 title		= {Linear Matrix Inequalities in Systems and Control Theory},
 publisher	= SIAM, address = SIAM-ADDRESS,
 year		= 1994}

@techreport{Bran95,
 author		= {M. A. Branch},
 title		= {Inexact reflective {N}ewton methods for large-scale
		   optimization subject to bound constraints},
 institution	= CS-CORNELL, address = CORNELL-ADDRESS,
 number		= {TR 95-1543}, year = 1995,
 abstract	= {This thesis addresses the problem of minimizing a
		   large-scale nonlinear function subject to simple bound
		   constraints. The most popular methods to handle bound
		   constrained problems, active-set methods, introduce a
		   combinatorial aspect to the problem. For these methods, the
		   number of steps to converge may be related to the number of
		   constraints. For large problems, this behavior is
		   particularly detrimental. Reflective Newton methods avoid
		   this problem by staying strictly within the constrained
		   region. As a result, these methods have strong theoretical
		   properties. Moreover, they behave experimentally like an
		   unconstrained method: the number of steps to a solution is
		   not strongly correlated with problem size. In this thesis,
		   we discuss the reflective Newton approach and how it can be
		   combined with inexact Newton techniques, within a subspace
		   trust-region method, to efficiently solve large problems.
		   Two algorithms are presented. The first uses a line search
		   as its globalizing strategy. The second uses a strictly
		   trust-region approach to globally converge to a local
		   minimizer. Global convergence and rate of convergence
		   results are established for both methods. We present
		   computational evidence that using inexact Newton steps
		   preserves the properties of the reflective Newton methods:
		   the iteration counts are as low as when ``exact'' Newton
		   steps are used. Also, both the inexact and exact methods
		   are robust when the starting point is varied. Furthermore,
		   the inexact reflective Newton methods have fast convergence
		   when negative curvature is encountered, a trait not always
		   shared by similar active-set type methods. The role of
		   negative curvature is further explored by comparing the
		   subspace trust-region approach to other common
		   approximations to the full-space trust-region problem. On
		   problems where only positive curvature is found, these
		   trust-region methods differ little in the number of
		   iterations to converge. However, for problems with negative
		   curvature, the subspace method is more effective in
		   capturing the negative curvature information, resulting in
		   faster convergence. Finally a parallel implementation on
		   the IBM SP2 is described and evaluated; the scalability and
		   efficiency of this implementation are shown to be as good
		   as the matrix-vector multiply routine it depends on.},
 summary	= {The problem of minimizing a large-scale nonlinear function
		   subject to simple bound constraints using the reflective
		   Newton approach is addressed, including how it can be
		   combined with inexact Newton techniques within a subspace
		   trust-region method. A linesearch and a trust-region
		   algorithm are presented, that have fast
		   convergence when negative curvature is encountered. The
		   subspace trust-region approach is compared to other
		   approximations to the trust-region subproblem. On problems
		   where only positive curvature is found, these 
		   methods differ little in efficiency. For problems with
		   negative curvature, the subspace method is more effective
		   in capturing the negative curvature information, resulting
		   in faster convergence. A parallel implementation on
		   the IBM SP2 is evaluated, whose scalability and efficiency
		   of are as good as the matrix-vector multiply
		   routine it depends on.}}

@techreport{BranColeLi95,
 author		= {M. A. Branch and T. F. Coleman and Y. Li},
 title		= {A subspace, interior, and conjugate gradient method for
		   large-scale bound-constrained minimization problems},
 institution	= CS-CORNELL, address = CORNELL-ADDRESS,
 number		= {TR 95-1525}, year = 1995,
 abstract	= {A subspace adaptation of the \citebb{ColeLi96b} trust
		   region and interior method is proposed for solving
		   large-scale bound-constrained minimization problems. This
		   method can be implemented with either sparse Cholesky
		   factorization or conjugate gradient computation. Under
		   reasonable conditions the convergence properties of this
		   subspace trust region method are as strong as those of its
		   full-space version. Computational performance on various
		   large-scale test problems are reported; advantages of our
		   approach are demonstrated. Our experience indicates our
		   proposed method represents an efficient way to solve
		   large-scale bound-constrained minimization problems.},
 summary	= {A subspace adaptation of the method by \citebb{ColeLi96b}
		   is proposed for solving large-scale bound-constrained
		   minimization problems. This method can be implemented with
		   either sparse Cholesky factorization or
		   conjugate-gradients. The convergence properties of this
		   subspace trust-region method are as strong as those of its
		   full-space version. Computational performance on
		   large-scale test problems illustrates its advantages.}}

@book{ColeBranGrac99,
 author         = {T. F. Coleman and M. A. Branch and A. Grace},
 title          = {Optimization Toolbox for Use with Matlab},
 publisher      = {The Math Works Inc.}, address = {Natick, Massuchussets, USA},
 year           = 1999}

@article{Breg67,
 author		= {L. M. Bregman},
 title		= {The relaxation method for finding the common points of
		   convex sets and its applications to the solution of
		   problems in convex programming},
 journal	= {USSR Computational Mathematics and Mathematical Physics},
 volume		= 7, pages = {200--217}, year = 1967}

@inproceedings{BreiShan93,
 author		= {M. G. Breitfeld and D. F. Shanno},
 title		= {Preliminary computational experience with modified
		   log-barrier functions for large-scale nonlinear programming},
 crossref	= {HageHearPard94}, pages = {45--66}}

@article{BreiShan96,
 author		= {M. G. Breitfeld and D. F. Shanno},
 title		= {Computational experience with penalty-barrier methods for
		   nonlinear programming},
 journal	= AOR,
 volume		= 62, pages = {439-463}, year = 1996}

@article{Bren73,
 author		= {R. P. Brent},
 title		= {Some efficient algorithms for solving systems of nonlinear
		   equations},
 journal	= SINUM,
 volume		= 10, number = 2, pages = {327--344}, year = 1973}

@article{BrimLove91,
 author         = {J. Brimberg and R. F. Love},
 title          = {Estimating travel distances by the weighted
                   $\ell_p$ norm},
 journal        = {Naval Research Logistics},
 volume         = 38, pages = {241-259}, year = 1991 }

@inproceedings{BroyAtti84,
 author		= {C. G. Broyden and N. F. Attia},
 title		= {A smooth sequential penalty function method for nonlinear
		   programming},
 crossref	= {BalaThom84}, pages = {237--245}}

@article{BroyAtti88,
 author		= {C. G. Broyden and N. F. Attia},
 title		= {Penalty functions, {N}ewton's method and quadratic
		   programming},
 journal	= JOTA,
 volume		= 58, number = 3, pages = {377--385}, year = 1988}

@article{Brow69,
 author		= {K. M. Brown},
 title		= {A quadratically convergent {N}ewton-like method based on
		   {G}aussian elimination},
 journal	= SINUM,
 volume		= 6, number = 4, pages = {560--569}, year = 1969}

@article{Broy70,
 author		= {C. G. Broyden},
 title		= {The Convergence Of A Class Of Double-rank Minimization
		   Algorithms},
 journal	= JIMA,
 volume		= 6, pages = {76--90}, year = 1970}

@article{Buck78a,
 author		= {A. G. Buckley},
 title		= {A Combined Conjugate-Gradient Quasi-{N}ewton Minimization
		   Algorithm},
 journal	= MP,
 volume		= 15, pages = {200--210}, year = 1978}

@article{Buck78b,
 author		= {A. G. Buckley},
 title		= {Extending the relationship between the conjugate gradient
		   and the {BFGS} algorithms},
 journal	= MP,
 volume		= 15, pages = {343--348}, year = 1978}

@article{BudiLeeSaxeFree96,
 author		= {D. E. Budil and S. Lee and S. Saxena and J. H. Freed},
 title		= {Nonlinear-least-squares analysis of slow-motion
		   {EPR}-spectra in one and 2 dimensions using a modified
		   {L}evenberg-{M}arquardt algorithm},
 journal	= {Journal of Magnetic Resonance, Series A},
 volume		= 120, number = 2, pages = {155--189}, year = 1996,
 abstract	= {The application of the model trust-region modification of
		   the Levenberg-Marquardt minimization algorithm to the
		   analysis of one-dimensional CW EPR and multidimensional
		   Fourier-transform (FT) EPR spectra especially in the
		   slow-motion regime is described. The dynamic parameters
		   describing the slow motion are obtained from least-squares
		   fitting of model calculations based on the stochastic
		   Liouville equation (SLE) to experimental spectra, the
		   trust-region approach is inherently more efficient than the
		   standard Levenberg-Marquardt algorithm, and the efficiency
		   of the procedure may be further increased by a
		   separation-of-variables method in which a subset of fitting
		   parameters is independently minimized at each iteration,
		   thus reducing the number of parameters to be fitted by
		   nonlinear least squares. A particularly useful application
		   of this method occurs in the fitting of multicomponent
		   spectra, for which it is possible to obtain the relative
		   population of each component by the separation-of-variables
		   method. These advantages, combined with recent improvements
		   in the computational methods used to solve the SLE, have
		   led to an order-of-magnitude reduction in computing time,
		   and have made it possible to carry out interactive,
		   real-time fitting on a laboratory workstation with a
		   graphical interface. Examples of fits to experimental data
		   will be given, including multicomponent CW EPR spectra as
		   well as two- and three- dimensional FT EPR spectra,
		   emphasis is placed on the analytic information available
		   from the partial derivatives utilized in the algorithm, and
		   how it may be used to estimate the condition and uniqueness
		   of the fit, as well as to estimate confidence limits for
		   the parameters in certain cases.},
 summary	= {The application of the model trust-region modification of
		   the Levenberg-Morrison-Marquardt algorithm to the analysis
		   of one-dimensional CW EPR and multidimensional
		   Fourier-transform (FT) EPR spectra especially in the
		   slow-motion regime is described. The dynamic parameters
		   describing the motion are obtained from least-squares
		   fitting of model calculations based on the stochastic
		   Liouville equation (SLE) to experimental spectra. The
		   trust-region approach is more efficient than the
		   standard Levenberg-Morrison-Marquardt algorithm, and the
		   efficiency of the procedure may be further increased by a
		   separation-of-variables method in which a subset of fitting
		   parameters is independently minimized at each iteration.
		   An application is the fitting of multicomponent spectra,
		   for which it is possible to obtain the relative population
		   of each component by the separation-of-variables method.
		   These advantages, combined with improvements in the
		   computational solution of the SLE, have led to an
		   order-of-magnitude reduction in computing time, and have
		   made it possible to carry out interactive, real-time
		   fitting on a laboratory workstation. Examples are given,
		   including multicomponent CW EPR spectra as well as two- and
		   three- dimensional FT EPR spectra.}}

@inproceedings{BulsSillSaxe92,
 author         = {A. B. Bulsari and M. Sillanpaa and H. Saxen},
 title          = {An expert system for continuous steel casting using neural 
                   networks},
 booktitle      = {Expert Systems in Mineral and Metal Processing. 
                   Proceedings of the IFAC Workshop},
 editor         = {J. L. Jamsa-Jounela and A. J. Niemi},
 publisher      = {Pergamon}, address = {Oxford, England},
 pages          = {155--159}, year = 1992,
 abstract       = {Developing an expert system is often time consuming
                   even after knowledge acquisition. Artificial neural
                   networks offer an advantageous alternative to coding
                   such knowledge in an expert system shell or writing a
                   program for it. This paper illustrates the
                   feasibility of using a feedforward neural network for
                   knowledge storage and inferencing for an industrial
                   problem. The inputs to the network were information
                   about an incoming ladle of steel, and the output was
                   about its suitability for successful continuous
                   casting, giving an indication on whether problems
                   would be encountered in the beginning and/or at the
                   end of the casting. A trust-region optimisation
                   method was used for training the networks, where the
                   input-output relation of the nodes was given by a
                   sigmoid function. This training method has been used
                   successfully for other neural network problems and
                   was found to be quite reliable and robust. By using a
                   feedforward neural network as an expert system for
                   predicting operational problems in the continuous
                   steel casting process, some inconsistencies in the
                   knowledge base were also revealed.},
 summary        = {A  feedforward neural network for knowledge storage
		   and inferencing is studied for an industrial
                   problem. The inputs to the network receive information
                   about an incoming ladle of steel, and the output predicts
                   its suitability for successful continuous
                   casting. A trust-region optimization
                   method is used for training the network. This training
		   method is found to be  reliable and robust.}}


@techreport{BultVial83,
 author		= {J. P. Bulteau and J. P. Vial},
 title		= {Unconstrained Optimization by Approximation of a Projected
		   Gradient Path},
 institution	= {CORE, UCL}, address = {Louvain-la-Neuve, Belgium},
 type		= {CORE Discussion Paper}, number = 8352, year = 1983,
 abstract	= {In an earlier paper \citebb{BultVial87} discussed a general
		   algorithm based on a one-dimensional search over a
		   curvilinear path according to a trust-region scheme. This
		   paper proposes a particular implementation of the general
		   algorithm using as a particular path an approximation of
		   the projected gradient path on a two dimensional space.
		   This algorithm is endowed with attractive convergence
		   properties. Newton and quasi-Newton like variants are
		   discussed, with corresponding numerical experiments.},
 summary	= {\citebb{BultVial87} discuss a general algorithm based on a
		   one-dimensional search over a curvilinear path according to
		   a trust-region scheme. An implementation using an
		   approximation of the projected gradient path on a 
		   two-dimensional space is given. This algorithm is endowed
		   with attractive convergence properties. Newton and
		   quasi-Newton like variants are discussed, with
		   corresponding numerical experiments.}}

@article{BultVial85,
 author		= {J. P. Bulteau and J. P. Vial},
 title		= {A restricted trust region algorithm for unconstrained
		   optimization},
 journal	= JOTA,
 volume		= 47, number = 4, pages = {413--435}, year = 1985,
 abstract	= {This paper proposes an efficient implementation of a
		   trust-region-like algorithm. The trust region is restricted
		   to an appropriately chosen two-dimensional subspace.
		   Convergence properties are discussed and numerical results
		   are reported.},
 summary	= {An efficient implementation of a trust-region method is
		   proposed, in which the trust region is restricted to an
		   appropriately chosen two-dimensional subspace. Convergence
		   properties are discussed and numerical results are
		   reported.}}

@article{BultVial87,
 author		= {J. P. Bulteau and J. P. Vial},
 title		= {Curvilinear path and trust region in unconstrained
		   optimization---a convergence analysis},
 journal	= MPS,
 volume		= 30, pages = {82--101}, year = 1987,
 abstract	= {In this paper we propose a general algorithm for solving
		   unconstrained optimization problems. The basic step of the
		   algorithm consists in finding a "good" successor point to
		   the current iterate by choosing it along a curvilinear path
		   within a trust region. This scheme is due to
		   \citebb{Powe70c} and has been applied by \citebb{Sore82} to
		   a particular type of path. We give a series of properties
		   that an arbitrary path should satisfy in order to achieve
		   global convergence and fast asymptotical convergence. We
		   review various paths that have been proposed in the
		   literature and study the extent to which they satisfy our
		   properties.},
 summary	= {A general algorithm for unconstrained optimization is
		   proposed. Its basic step consists in finding a "good"
		   successor point to the current iterate by choosing it along
		   a curvilinear path within a trust region. Properties that
		   an arbitrary path should satisfy in order to achieve global
		   convergence and fast asymptotic convergence are given.
		   Various paths that have been proposed in the literature are
		   reviewed in this light.}}

@article{Bunc74,
 author		= {J. R. Bunch},
 title		= {Partial pivoting strategies for symmetric matrices},
 journal	= SINUM,
 volume		= 11, pages = {521--528}, year = 1974}

@article{BuncGayWels93,
 author         = {D. S. Bunch and D. M. Gay and R. E. Welsch},
 title          = {Algorithm 717: subroutines for maximum likelihood and 
                  quasi-likelihood estimation of parameters in nonlinear 
                  regression models},
 journal        = TOMS,
 volume         = 19, number = 1, pages = {109--130}, year = 1993,
 abstract       = {The authors present FORTRAN 77 subroutines that solve
                   statistical parameter estimation problems for general
                   nonlinear models, e.g., nonlinear least-squares,
                   maximum likelihood, maximum quasi-likelihood,
                   generalized nonlinear least-squares, and some robust
                   fitting problems. The accompanying test examples
                   include members of the generalized linear model
                   family, extensions using nonlinear predictors
                   ('nonlinear GLIM'), and probabilistic choice models,
                   such as linear-in-parameter multinomial probit
                   models. The basic method, a generalization of the
                   NL2SOL algorithm for nonlinear least-squares, employs
                   a model/trust-region scheme for computing trial
                   steps, exploits special structure by maintaining a
                   secant approximation to the second-order part of the
                   Hessian, and adaptively switches between a
                   Gauss-Newton and an augmented Hessian
                   approximation. Gauss-Newton steps are computed using
                   a corrected seminormal equations approach. The
                   subroutines include variants that handle simple
                   bounds on the parameters, and that compute
                   approximate regression diagnostics.},
 summary        = {FORTRAN 77 subroutines are presented that solve
                   statistical parameter estimation problems for general
                   nonlinear models, e.g., nonlinear least-squares,
                   maximum likelihood, maximum quasi-likelihood,
                   generalized nonlinear least-squares, and some robust
                   fitting problems. The basic method, a generalization 
                   of the NL2SOL algorithm for nonlinear least-squares,
                   employs a model/trust-region scheme for computing trial
                   steps, maintain a secant approximation to the
		   second-order part of the Hessian, and adaptively switches
		   between Gauss-Newton and full Newton
                   approximations. Gauss-Newton steps are computed using
                   a corrected seminormal equations approach. The
                   subroutines include variants that handle simple
                   bounds on the parameters, and that compute
                   approximate regression diagnostics.}}


@article{BuncKauf77,
 author		= {J. R. Bunch and L. C. Kaufman},
 title		= {Some stable methods for calculating inertia and solving
		   symmetric linear equations},
 journal	= MC,
 volume		= 31, pages = {163--179}, year = 1977}

@article{BuncKauf80,
 author 	= {J. R. Bunch and L. C. Kaufman},
 title  	= {A computational method for the indefinite quadratic
		   programming problem},
 journal 	= LAA,
 volume 	= 34, pages = {341-370}, year = 1980}

@article{BuncParl71,
 author		= {J. R. Bunch and B. N. Parlett},
 title		= {Direct methods for solving symmetric indefinite systems of
		   linear equations},
 journal	= SINUM,
 volume		= 8, number = 4, pages = {639--655}, year = 1971}

@article{Burk90,
 author		= {J. V. Burke},
 title		= {On the identification of active constraints {II}: the
		   nonconvex case},
 journal	= SINUM,
 volume		= 27, number = 4, pages = {1081--1102}, year = 1990,
 abstract	= {In this paper the results of \citebb{BurkMore88} on the
		   identification of active constraints are extended to the
		   nonconvex constrained nonlinear programming problem. The
		   approach is motivated by the geometric structure of certain
		   polyhedral convex ``linearization'' of the constraint
		   region at each iteration. As in \citebb{BurkMore88}
		   questions of constraint identification are couched in
		   termes of the faces of these polyhedra. The main result
		   employs a nondegeneracy condition due to \citebb{Dunn87}
		   and the linear independence condition to obtain a
		   characterization of those algorithms that identify the
		   optimal active constraints in a finite number of
		   iterations. The role of the linear independence condition
		   is carefully examined and it is argued that it is required
		   within the context of the
		   \citebb{Wils63}--\citebb{Han77}--\citebb{Powe78} sequential
		   quadratic programming algorithm and \citebb{Flet87}'s $QL$
		   algorithm.},
 summary	= {The results of \citebb{BurkMore88}, on the identification
		   of active constraints, are extended to non-convex
		   constrained programming. The approach is
		   motivated by the geometric structure of certain polyhedral
		   convex ``linearization'' of the constraint region at each
		   iteration. Questions of constraint identification are
		   couched in termes of the faces of these polyhedra. The main
		   result employs a non-degeneracy condition due to
		   \citebb{Dunn87} and the linear independence condition to
		   obtain a characterization of those algorithms that identify
		   the optimal active constraints in a finite number of
		   iterations. It is argued that the linear independence
		   condition is required for the Wilson--Han--Powell SQP
		   algorithm and for Fletcher's $QL$ algorithm.}}

@article{Burk92,
 author		= {J. V. Burke},
 title		= {A Robust Trust Region Method for Constrained Nonlinear
		   Programming Problems},
 journal	= SIOPT,
 volume		= 2, number = 2, pages = {324--347}, year = 1992,
 abstract	= {Most of the published work on trust region algorithms for
		   constrained optimization is derived from the original work
		   of \citebb{Flet87} on trust region algorithms for
		   nondifferentiable exact penalty functions. These methods
		   are restricted to applications where a reasonable estimate
		   of the magnitude of the optimal Kuhn-Tucker multiplier
		   vector can be given, More recently an effort has been made
		   to extend the trust region methodology to the sequential
		   quadratic programming (SQP) algorithm of \citebb{Wils63},
		   \citebb{Han77} and \citebb{Powe78}. All of these extensions
		   to the Wilson--Han--Powell SQP algorithm consider only the
		   equality-constrained case and require strong global
		   regularity hypotheses. This paper presents a general
		   framework for trust region algorithms for constrained
		   problems that does not require such regularity hypotheses
		   and allows very general constraints. The approach is
		   modeled on the one given by Powell for convex composite
		   optimization problems and is driven by linear subproblems
		   that yield viable estimates for the value of an exact
		   penalty parameter. These results are applied to the
		   Wilson--Han--Powell SQP algorithm and Fletcher's
		   S$\ell_1$QP algorithm. Local convergence results are also
		   given.},
 summary	= {A general framework for trust-region algorithms for
		   constrained problems is presented, that does not require
		   strong regularity hypotheses and allows very general
		   constraints. The approach is modeled on the one given by
		   Powell for convex composite optimization problems and is
		   driven by linear subproblems that yield viable estimates
		   for the value of an exact penalty parameter. These results
		   are applied to the Wilson-Han-Powell SQP algorithm and
		   Fletcher's S$\ell_1$QP algorithm. Local convergence results
		   are given.}}

@article{BurkHan89,
 author		= {J. V. Burke and S. P. Han},
 title		= {A robust sequential quadratic-programming method},
 journal	= MP,
 volume		= 43, number = 3, pages = {277--303}, year = 1989}

@article{BurkMore88,
 author		= {J. V. Burke and J. J. Mor\'{e}},
 title		= {On the identification of active constraints},
 journal	= SINUM,
 volume		= 25, number = 5, pages = {1197--1211}, year = 1988,
 abstract	= {Nondegeneracy conditions that guarantee that the optimal
		   active constraints are identified in a finite number of
		   iterations are studied. Results of this type have only been
		   established for a few algorithms, and then under
		   restrictive hypothesis. The main result is a
		   characterization of those algorithms that identify the
		   optimal constraints in a finite number of iterations. This
		   result is obtained with a non-degeneracy assumption which is
		   equivalent, in the standard nonlinear programming problem,
		   to the assumption that there is a set of strictly
		   complementary Lagrange multipliers. As an important
		   consequence of the authors' results the way that this
		   characterization applies to gradient projection and
		   sequential quadratic programming algorithms is shown.},
 summary	= {Non-degeneracy conditions that guarantee that the optimal
		   active constraints are identified in a finite number of
		   iterations are studied and a characterization of those
		   algorithms that identify the optimal constraints in a
		   finite number of iterations is derived. This result is
		   obtained with a non-degeneracy assumption which is
		   equivalent, in the standard nonlinear programming problem,
		   to the assumption that there is a set of strictly
		   complementary Lagrange multipliers. As an important
		   consequence, the way that this characterization applies to
		   gradient projection and sequential quadratic programming
		   algorithms is shown.}}

@article{BurkMoreTora90,
 author		= {J. V. Burke and J. J. Mor\'{e} and G. Toraldo},
 title		= {Convergence properties of trust region methods for linear
		   and convex constraints},
 journal	= MPA,
 volume		= 47, number = 3, pages = {305--336}, year = 1990,
 abstract	= {We develop a convergence theory for convex and linearly
		   constrained trust region methods which only requires that
		   the step between iterates produce a sufficient reduction in
		   the trust region subproblem. Global convergence is
		   established for a general convex minimization problem while
		   local analysis is for linearly constrained problems. The
		   main local result establishes that if the sequence
		   converges to a nondegenerate stationary point then the
		   active constraints at the solution are identified in a
		   finite number of iterations. As a consequence of the
		   identification properties, we develop rate of convergence
		   results by assuming that the step is a truncated Newton
		   method. Our development is mainly geometrical; this
		   approach allows the development of a convergence theory
		   without any linear independence assumptions.},
 summary	= {A convergence theory is developed for convex and linearly
		   constrained trust-region methods which only requires that
		   the step between iterates produce a sufficient reduction in
		   the subproblem. Global convergence is established for a
		   general convex problem while local analysis is for linearly
		   constrained problems. It is shown that if the sequence
		   converges to a non-degenerate stationary point then the
		   active constraints at the solution are identified in a
		   finite number of iterations. As a consequence, rate of
		   convergence results are developed by assuming that the step
		   is a truncated Newton method. This development is mainly
		   geometrical; such an approach allows the development of a
		   convergence theory without any linear independence
		   assumptions.}}

@article{BurkMore95,
 author		= {J. V. Burke and J. J. Mor\'{e}},
 title		= {Exposing Constraints},
 journal	= SIOPT,
 volume		= 4, number = 3, pages = {573--595}, year = 1994,
 abstract	= {The development of algorithms and software for the solution
		   of large-scale optimization problems has been the main
		   motivation behind the research on the identification
		   properties of optimization algorithms. The aim of an
		   identification result for a linearly constrained problem is
		   to show that if the sequence generated by an optimization
		   algorithm converges to a stationary point, then there is a
		   nontrivial face $F$ of the feasible set such that after a
		   finite number of iterations, the iterates enter and remain
		   in the face $F$. The paper develops the identification
		   properties of linearly constrained optimization algorithms
		   without any nondegeneracy or linear independence
		   assumptions. The main result shows that the projected
		   gradient converges to zero if and only if the iterates
		   enter and remain in the face exposed by the negative
		   gradient. This result generalizes results of
		   \citebb{BurkMore88} for nondegenerate cases.},
 summary	= {The identification properties of linearly constrained
		   optimization algorithms is developed without any
		   non-degeneracy or linear independence assumptions. It shown
		   that the projected gradient converges to zero if and only
		   if the iterates enter and remain in the face exposed by the
		   negative gradient, which generalizes results of
		   \citebb{BurkMore88} for non-degenerate cases.}}

@misc{BurkWeig97,
 author         = {J. V. Burke and A. Weigmann},
 title          = {Notes on Limited Memory BFGS Updating in A Trust-Region
                   Framework},
 institution    = {Department of Mathematics, University of Washington},
 address        = {Seattle, Washington, USA},
 year           = 1997,
 abstract       = {The limited memory BFGS method pioneered by Jorge Nocedal
                   is usually implemented as a line search method where the
                   search direction is computed from a BFGS approximation to
                   the inverse of the Hessian.  the advantage of inverse
                   updating is that the serach directions are obtained by a
                   matrix-vector multiplication.  Furthermore, experience
                   shows that when the BFSG approximation is appropriately
                   re-scaled (or re-sized) at each iteration, the line search
                   stopping criteria are often satisfied for the first trial
                   step.  In this note it is observed that limited memory
                   updates to the Hessian approximations can also be applied
                   in the context of a trust-region algorithm with only modest
                   increase in the linear algebra costs.  This is true even
                   though in the trust-region framework one maintains
                   approximations to the Hessian rather than its inverse.  
                   The key to this observation is the compact form of the
                   limited memory updates derived by Byrd, Nocedal and Schnabel
                   (1994).  Numerical results on a few of the MINPACK-2 test
                   problems indicate that an implementation that incorporates
                   re-scaling directly into the trust-region updating
                   procedure exhibits convergence behavior comparable to a
                   standard implementation of the algorithm by 
                   \citebb{LiuNoce89}.},
 summary        = {A limited-memory BFGS method is described that uses 
                   re-scaling at each iteration and a trust-region technique 
                   to ensure convergence. The effects of a non-monotone 
                   technique as well as that of an implicit scheme for 
                   updating the trust-region radius are dicussed. Numerical 
                   experiments are reported.}}

@article{ButcJackMitt97,
 author		= {J. C. Butcher and Z. Jackiewicz and H. D. Mittelmann},
 title		= {A nonlinear optimization approach to the construction of
		   general linear methods of high order},
 journal	= JCAM,
 volume		= 81, number = 2, pages = {181--196}, year = 1997,
 abstract	= {We describe the construction of diagonally implicit
		   multistage integration methods of order and stage order
		   $p=q=7$ and $p=q=8$ for ordinary differential equations.
		   These methods were obtained using state-of-the-art
		   optimization methods, particularly variable- model
		   trust-region least-squares algorithms.},
 summary	= {The construction of diagonally implicit multistage
		   integration methods of order and stage order $p=q=7$ and
		   $p=q=8$ for ordinary differential equations is described.
		   These methods were obtained using variable-model
		   trust-region least-squares algorithms.}}

@article{Byrd90,
 author		= {R. H. Byrd},
 title		= {On the Convergence of Constrained Optimization Methods with
		   Accurate {H}essian Information on a Subspace},
 journal	= SINUM,
 volume		= 27, number = 1, pages = {141--153}, year = 1990}

@misc{Byrd99,
 author		= {R. H. Byrd},
 title		= {Step Computation in a Trust Region Interior Point Method},
 howpublished   = {Presentation at the First Workshop on Nonlinear
                   Optimization ``Interior-Point and Filter Methods'',
                   Coimbra, Portugal},
 year           = 1999,
 abstract       = {In computing a step on an interior point method for
                   nonlinear inequality constrained optimization, use of
                   a trust region provides a unified structure for dealing
                   with negative curvature and rank deficiency.  However, in
                   an interior point context, exactly solving the complete
                   trust region subproblem step presents us with an
                   intractable subproblem.  Therefore, most practical methods
                   use a cheap approximate solution to the trust region
                   problem.  Here, we consider several of these approximate
                   methods, and point out that methods that are theoretically
                   adequate can have serious drawbacks.  We present some new
                   approaches to this problem and argue that in many cases
                   simpler is better.  We also consider to what extent these
                   approximate approaches provide the benefits promised by
                   trust regions in the cases of negative curvature and rank
                   deficiency.},
 summary        = {Approximate methods for computing a trust-region step in
                   an interior point method for nonlinear inequality constrained
                   optimization are considered, and some new approaches
                   proposed. The extent to which they provide the benefits
                   promised by trust regions in the cases of negative
                   curvature and rank deficiency are also discussed.}} 

@article{ByrdNoce91,
 author		= {R. H. Byrd and J. Nocedal},
 title		= {An analysis of reduced {H}essian methods for constrained
		   optimization},
 journal	= MP,
 volume		= 49, number = 3, pages = {285--323}, year = 1991}

@techreport{ByrdGilbNoce96,
 author		= {R. H. Byrd and J. Ch. Gilbert and J. Nocedal},
 title		= {A Trust Region Method Based on Interior Point Techniques
		   for Nonlinear Programming},
 institution	= {INRIA}, address = {Rocquencourt, France},
 number		= 2896, year = 1996,
 abstract	= {An algorithm for minimizing a nonlinear function subject to
		   nonlinear equality and inequality constraints is described.
		   It can be seen as an extension of primal interior point
		   methods to non-convex optimization. The new algorithm
		   applies sequential quadratic programming techniques to a
		   sequence of barrier problems, and uses trust regions to
		   ensure the robustness of the iteration and to allow the
		   direct use of second order derivatives. An analysis of the
		   convergence of the new method is presented.},
 summary	= {An algorithm for minimizing a nonlinear function subject to
		   nonlinear equality and inequality constraints is described.
		   It can be seen as an extension of primal interior-point
		   methods to non-convex optimization. The algorithm applies
		   SQP techniques to a sequence of barrier problems, and uses
		   trust regions to ensure the robustness of the iteration and
		   to allow the direct use of second order derivatives. A
		   convergence analysis is presented.}}

@article{ByrdHribNoce99,
 author		= {R. H. Byrd and M. E. Hribar and J. Nocedal},
 title		= {An Interior Point Algorithm for Large Scale Nonlinear
		   Programming},
 journal        = SIOPT,
 volume         = 9, number = 4, pages = {877-900}, year = 2000,
 abstract	= {We describe a new algorithm for solving large nonlinear
		   programming problems. It incorporates within the interior
		   point method two powerful tools for solving nonlinear
		   problems: sequential quadratic programming (SQP) and trust
		   region techniques. SQP ideas are used to efficiently handle
		   nonlinearities in the constraints. Trust region strategies
		   allow the algorithm to treat convex and non-convex problems
		   uniformly, permit the direct use of second derivative
		   information and provide a safeguard in the presence of
		   nearly dependent constraint gradients. Both primal and
		   primal-dual versions of the algorithm are developed, and
		   their performance is compared with that of LANCELOT on a
		   set of large and difficult nonlinear problems.},
 summary	= {An algorithm for solving large nonlinear programming
		   problems is described. It incorporates 
		   SQP and trust-region techniques within the
		   interior-point method. SQP ideas are used to efficiently
		   handle nonlinearities in the constraints. Trust-region
		   strategies allow the algorithm to treat convex and
		   non-convex problems uniformly, permit the direct use of
		   second derivative information and provide a safeguard in
		   the presence of nearly dependent constraint gradients. Both
		   primal and primal-dual versions of the algorithm are
		   developed, and their performance is compared with that of
		   {\sf LANCELOT} on a set of large and difficult nonlinear
		   problems.}}

@techreport{ByrdNoceWalt00,
 author		= {R. H. Byrd and J. Nocedal and R. A. Waltz},
 title		= {Feasible Interior Methods Using Slacks for Nonlinear
                   Optimization},
 institution    = OTC, address = OTC-ADDRESS,
 number         = 11, year = 2000,
 abstract       = {A slack-based feasible interior point method is described
                   which can be derived as a modification of infeasible methods.
                   The modification is minor for most line search methods, but
                   trust region methods require special attention.  It is shown
                   how the Cauchy point, which is often computed in trust region
                   methods, must be modified so that the feasible method is
                   effective for problems containing both equality and 
                   inequality constraints.  The relationship between 
                   slack-based methods and traditional feasible methods is 
                   discussed. Numerical results showing the relative performance
                   of feasible versus infeasible interior point methods are 
                   presented.},
 summary        = {A slack-based feasible interior-point method is described
                   which can be derived as a modification of infeasible methods.
                   The modification is minor for most line search methods, but
                   trust-region methods require special attention.  It is shown
                   how the Cauchy point must be modified so that the feasible
                   trust-region method is effective for problems containing 
                   both equality and inequality constraints.  The relationship 
                   between slack-based methods and traditional feasible methods 
                   is discussed. Numerical results showing the relative 
                   performance of feasible versus infeasible interior-point 
                   methods are presented.}}

@article{ByrdKhalSchn96,
 author		= {R. H. Byrd and H. F. Khalfan and R. B. Schnabel},
 title		= {Analysis of a symmetric rank-one trust region method},
 journal	= SIOPT,
 volume		= 6, number = 4, pages = {1025--1039}, year = 1996,
 abstract	= {Several recent computational studies have shown that the
		   symmetric rank-one (SR1) method for unconstrained
		   optimization and shows that the method has an $n+1$ step
		   $q$-superlinear rate of convergence. The analysis makes
		   neither of the assumptions of uniform linear independence
		   of the iterates nor positive definiteness of the Hessian
		   approximations that have been made in other recent analysis
		   of SR1 methods. The trust region method that is analyzed is
		   fairly standard, except that it includes the feature that
		   the Hessian approximation is updated after all steps,
		   including rejected steps. We also present computational
		   results that show that this feature, safeguarded in a way
		   that is consistent with the convergence analysis, does not
		   harm the efficiency of the SR1 trust region method.},
 summary	= {Computational studies have considered the
		   symmetric rank-one (SR1) method for unconstrained
		   optimization and shown that the method has an $n+1$ step
		   $q$-superlinear rate of convergence. The proposed analysis
		   makes neither of the assumptions of uniform linear
		   independence of the iterates nor positive definiteness of
		   the Hessian approximations that have been made in former
		   such analyses. The trust-region method is standard, but
		   requires the Hessian approximation to be updated after
		   all steps, including rejected ones. Computational results
		   indicate that this feature, safeguarded in a way that is
		   consistent with the convergence analysis, does not harm
		   the efficiency of the SR1 trust-region method.}}

@article{ByrdLuNoceZhu95,
 author		= {R. H. Byrd and P. Lu and J. Nocedal and C. Zhu},
 title		= {A limited memory algorithm for bound constrained
optimization}, 
 journal	= SISC,
 volume		= 16, number = 5, pages = {1190--1208}, year = 1995}

@article{ByrdSchn86,
 author		= {R. H. Byrd and R. B. Schnabel},
 title		= {Continuity of the null space basis and constrained
		   optimization},
 journal	= MP,
 volume		= 35, number = 1, pages = {32--41}, year = 1986}

@article{ByrdSchnShul87,
 author		= {R. H. Byrd and R. B. Schnabel and G. A. Shultz},
 title		= {A trust region algorithm for nonlinearly constrained
		   optimization},
 journal	= SINUM,
 volume		= 24, pages = {1152--1170}, year = 1987,
 abstract	= {We present a trust region-based method for the general
		   nonlinearly constrained optimization problem. The method
		   works by iteratively minimizing a quadratic model of the
		   Lagrangian subject to a possibly relaxed linearization of
		   the problem constraints and a trust region constraint. The
		   model minimization may be done approximately with a
		   dogleg-type approach. We show that this method is globally
		   convergent even if singular or indefinite Hessian
		   approximations are made. A second order correction step
		   that brings the iterates closer to the feasible set is
		   described. If sufficiently precise Hessian information is
		   used, this correction step allows us to prove that the
		   method is also locally quadratically convergent, and that
		   the limit satisfies the second order necessary conditions
		   for constrained optimization. An example is given to show
		   that, without this correction, a situation similar to the
		   \citebb{Mara78} effect may occur where the iteration is
		   unable to move away from a saddle point.},
 summary	= {A trust-region-based method is given for general
		   nonlinearly constrained optimization problem. It
		   iteratively minimizes a quadratic model of the Lagrangian
		   subject to a possibly relaxed linearization of the problem
		   constraints and a trust-region constraint. The model
		   minimization may be done approximately with a dogleg-type
		   approach. Global convergence is shown.  A second order
		   correction step is also described. If sufficiently precise
		   Hessian  information is used, this step ensures 
		   locally quadratically convergence and 
		   satisfaction of the second order necessary conditions.
		   An example shows
		   that, without this correction, a situation similar to the
		   \citebb{Mara78} effect may occur where the iteration is
		   unable to move away from a saddle point.}}

@article{ByrdSchnShul88,
 author		= {R. H. Byrd and R. B. Schnabel and G. A. Shultz},
 title		= {Approximate solution of the trust region problem by
		   minimization over two-dimensional subspaces},
 journal	= MP,
 volume		= 40, number = 3, pages = {247--263}, year = 1988,
 abstract	= {The trust region problem, minimization of a quadratic
		   function subject to a spherical trust region constraint,
		   occurs in many optimization algorithms. In a previous
		   paper, the authors introduced an inexpensive approximate
		   solution technique for this problem that involves the
		   solution of a two-dimensional trust region problem. They
		   showed that using this approximation in an unconstrained
		   optimization algorithm leads to the same theoretical global
		   and local convergence properties as are obtained using the
		   exact solution to the trust region problem. This paper
		   reports computational results showing that the
		   two-dimensional minimization approach gives nearly optimal
		   reductions in the $n$-dimension quadratic model over a wide
		   range of test cases. We also show that there is very little
		   difference, in efficiency and reliability, between using
		   the approximate or exact trust region step in solving
		   standard test problems for unconstrained optimization.
		   These results may encourage the application of similar
		   approximate trust region techniques in other contexts.},
 summary	= {Computational results are given, showing that the
		   two-dimensional minimization approach of
		   \citebb{ByrdSchnShul87} gives nearly optimal reductions in
		   the $n$-dimensional quadratic model over a wide range of
		   test cases. It is also shown that there is very little
		   difference, in efficiency and reliability, between using
		   the approximate or exact trust-region step when solving
		   standard test problems for unconstrained optimization.}}

@article{ByrdTapiZhan92,
 author		= {R. H. Byrd and R. A. Tapia and Y. Zhang},
 title		= {An {SQP} Augmented {L}agrangian {BFGS} Algorithm for
		   Constrained Optimization},
 journal	= SIOPT,
 volume		= 2, number = 2, pages = {210--241}, year = 1992}

%%% C %%%

@article{CalaMore87,
 author		= {P. H. Calamai and J. J. Mor\'{e}},
 title		= {Projected gradient methods for linearly constrained
		   problems},
 journal	= MP,
 volume		= 39, pages = {93--116}, year = 1987}

@article{CarpLustMulvShan93,
 author 	= {T. J. Carpenter and I. J. Lustig and J. M. Mulvey
		   and D. F. Shanno},
 title  	= {Higher-Order Predictor-Corrector Interior Point Methods with
          	   Application to Quadratic Objectives},
 journal 	= SIOPT,
 volume 	= 3, number = 4, pages = {696--725}, year = 1993}

@phdthesis{Carr59,
 author		= {C. W. Carrol},
 title		= {An operations research approach to the economic
		   optimization of a kraft pulping process},
 school		= {Institute of Paper Chemistry},
 address	= {Appleton, Wisconsin, USA},
 year		= 1959}

@article{Carr61,
 author		= {C. W. Carrol},
 title		= {The Created Response Surface Technique for Optimizing
		   Nonlinear Restrained Systems},
 journal	= {Operations Research},
 volume		= 9, number = 2, pages = {169--184}, year = 1961}

@techreport{Cart86,
 author		= {R. G. Carter},
 title		= {Multi-Model Algorithms for Optimization},
 institution	= CAAM, address = RICE-ADDRESS,
 number		= {TR86-3}, year = 1986,
 abstract	= {A recent approach for the construction of nonlinear
		   optimization software has been to allow an algorithm to
		   choose between two possible models to the objective
		   function at each iteration. The model switching algorithm
		   NL2SOL of \citebb{DennGayWels81} and the hybrid algorithms
		   of Al-Baali and Fletcher have proven highly effective in
		   practice. Although not explicitly formulated as multi-model
		   methods, many other algorithms implicitly perform a model
		   switch under certain circumstances (e.g., resetting a
		   secant model to the exact value of the Hessian). We present
		   a trust region formulation for multi-model methods which
		   allows the efficient incorporation of an arbitrary number
		   of models. Global convergence can be shown for three
		   classes of algorithms under different assumptions on the
		   models. First, essentially any multi-model algorithm is
		   globally convergent if each of the models is sufficiently
		   well-behaved. Second, algorithms based on the central
		   feature of the NL2SOL switching system are globally
		   convergent if one model is well behaved and each other
		   model obeys a ``sufficient predicted decrease'' condition.
		   No requirement is made that these alternate models be
		   quadratic. Third, algorithms of the second type which
		   directly enforce the ``sufficient predicted decrease''
		   condition are globally convergent if a single model is
		   sufficiently well behaved.},
 summary	= {A trust-region formulation for multi-model methods is
		   presented which allows the efficient incorporation of an
		   arbitrary number of models. Global convergence is
		   established for three classes of algorithms under different
		   assumptions on the models. Firstly, essentially any
		   multi-model algorithm is globally convergent if each of the
		   models is sufficiently well-behaved. Secondly, algorithms
		   based on the central feature of the NL2SOL switching system
		   are globally convergent if one model is well behaved and
		   each other model obeys a ``sufficient predicted decrease''
		   condition. No requirement is made that these alternate
		   models be quadratic. Finally, algorithms of the second type
		   which directly enforce the ``sufficient predicted
		   decrease'' condition are globally convergent if a single
		   model is sufficiently well behaved.}}

@techreport{Cart87,
 author		= {R. G. Carter},
 title		= {Safeguarding {H}essian Approximations in Trust Region
		   Algorithms},
 institution	= CAAM, address = RICE-ADDRESS,
 number		= {TR87-12}, year = 1987,
 abstract	= {In establishing global convergence results for trust region
		   algorithms applied to unconstrained optimization, it is
		   customary to assume either a uniform upper bound on the
		   sequence of Hessian approximations or an upper bound linear
		   in the iteration count. The former property has not been
		   established for most commonly used secant updates, and the
		   latter has only been established for some updates under the
		   highly restrictive assumption of convexity. One purpose of
		   the uniform upper bound assumption is to establish a
		   technical condition we refer to as the \emph{uniform
		   predicted decrease condition}. We show that this condition
		   can also be obtained by milder assumptions, the simplest of
		   which is a uniform upper bound on the sequence of Rayleigh
		   quotients of the Hessian approximations \emph{in the
		   gradient directions}. This in turn suggests both a simple
		   procedure for detecting questionable Hessian
		   approximations, and several natural procedures for {\em
		   correcting} them when detected. In numerical testing, one
		   of these procedures increased the reliability of the
		   popular BFGS method by a factor of two (i.e., the procedure
		   halved the number of test cases to fail to converge to a
		   critical point in a reasonable number of iterations).
		   Further, for those problems where both methods were
		   successful, this safeguarding procedure actually improved
		   the average efficiency of the BFGS by ten to twenty
		   percent.},
 summary	= {It is shown that the assumptions on the Hessian
		   approximations in a trust-region method for unconstrained
		   optimization can be replaced by a uniform upper bound on
		   the sequence of Rayleigh quotients of the Hessian
		   approximations in the gradient directions. This suggests
		   both a simple procedure for detecting questionable
		   approximations, and several natural procedures for
		   correcting them when detected. In numerical tests, one of
		   these procedures increased the reliability of the BFGS
		   method by a factor of two. For those problems where both
		   the safeguarded and original methods were successful, this
		   safeguarding procedure improved the average efficiency of
		   the BFGS by ten to twenty percent.}}

@article{Cart91,
 author		= {R. G. Carter},
 title		= {On the global convergence of trust region methods using
		   inexact gradient information},
 journal	= SINUM,
 volume		= 28, number = 1, pages = {251--265}, year = 1991,
 abstract	= {Trust region algorithms are an important class of methods
		   that can be used to solve unconstrained optimization
		   problems. Strong global convergence results are
		   demonstrated for a class of methods where the gradient
		   values are approximated rather than computed exactly,
		   provided they obey a simple relative error condition. No
		   requirement is made that gradients be recomputed to
		   successively greater accuracy after unsuccessful
		   iterations.},
 summary	= {Strong global convergence results are demonstrated for
		   trust-region methods for unconstrained minimization where
		   the gradient values are approximated rather than computed
		   exactly, provided they obey a simple relative error
		   condition. No requirement is made that gradients be
		   recomputed to successively greater accuracy after
		   unsuccessful iterations.}}

@article{Cart93,
 author		= {R. G. Carter},
 title		= {Numerical Experience with a class of Algorithms for
		   nonlinear Optimization using inexact function and gradient
		   information},
 journal	= SISSC,
 volume		= 14, number = 2, pages = {368--388}, year = 1993,
 abstract       = {For optimization problems associated with engineering
                   design, parameter estimation, image reconstruction,
                   and other optimization/simulation applications, low
                   accuracy function and gradient values are frequently
                   much less expensive to obtain than high accuracy
                   values. The computational performance of trust region
                   methods for nonlinear optimization is investigated
                   for cases when high accuracy evaluations are
                   unavailable or prohibitively expensive, and earlier
                   theoretical predictions that such methods are
                   convergent even with relative gradient errors of 0.5
                   or more is confirmed. The proper choice of the amount
                   of accuracy to use in function and gradient
                   evaluations can result in orders-of-magnitude savings
                   in computational cost.},
 summary        = {The computational performance of trust-region
                   methods for nonlinear optimization is investigated
                   for cases when high accuracy evaluations of function and
		   gradient are unavailable or prohibitively expensive, and
                   theoretical predictions that such methods are
                   convergent even with relative gradient errors of 0.5
                   or more is confirmed. The proper choice of the amount
                   of accuracy to use in function and gradient
                   evaluations can result in orders-of-magnitude savings
                   in computational cost.}}

@phdthesis{Case97,
 author		= {L. Case},
 title		= {An $\ell_1$ penalty function approach to the nonlinear
		   bilevel programming problem},
 school		= {University of Waterloo}, address = {Waterloo, Canada},
 year		= 1997,
 summary        = {The nonlinear bilevel problem is a difficult constrained 
                   optimization problem where the variables are partitioned
                   into two sets, $z$ and $y$.
                   The feasibility conditions require that y is the solution
                   of a separate optimization problem.
                   The approach of this thesis replaces the original problem
                   by stating the necessary conditions for a solution and 
                   determining a one level programming problem by using
                   an exact penalty function to attempt to satisfy these 
                   conditions. The resulting non-convex, non-smooth problems
		   are solved by a trust-region approach and specialized 
		   techniques are used to overcome difficulties arising from 
		   the non-differentiability. A unique method is developed
		   to handle degeneracy. Proof of convergence to a minimum
		   of the penalty function is given. Test results and an 
		   analysis of the solutions are included.
                   }}

@article{Cauc47,
 author		= {A. Cauchy},
 title		= {M\'{e}thode g\'{e}n\'{e}rale pour la r\'{e}solution des
		   syst\`{e}mes d'\'{e}quations simultan\'{e}es},
 journal	= {Comptes Rendus de l'Acad\'{e}mie des Sciences},
 pages		= {536--538}, year = 1847}

@techreport{Celi85,
 author		= {M. R. Celis},
 title		= {A Trust Region Strategy for Nonlinear Equality Constrained
		   Optimization.},
 institution	= CAAM, address = RICE-ADDRESS,
 number		= {TR85-4}, year = 1985,
 abstract	= {Many current algorithms for nonlinear constrained
		   optimization problems determine a search direction by
		   solving a quadratic programming subproblem. The global
		   convergence properties are addressed by using a line search
		   technique and a merit function to modify the length of the
		   step obtained from the quadratic program. In unconstrained
		   optimization, trust region strategies have been very
		   successful. In this thesis we present a new approach for
		   equality constrained optimization problems based on a trust
		   region strategy. The direction selected is not necessarily
		   the solution of the standard quadratic programming
		   subproblem.},
 summary	= {An approach for equality constrained optimization problems
		   based on a trust-region strategy is presented. The
		   direction selected is not necessarily the solution of the
		   standard quadratic programming subproblem.}}

@inproceedings{CeliDennTapi85,
 author		= {M. R. Celis and J. E. Dennis and R. A. Tapia},
 title		= {A trust region strategy for nonlinear equality constrained
		   optimization},
 crossref	= {BoggByrdSchn85}, pages = {71--82},
 abstract	= {Many current algorithms for nonlinear constrained
		   optimization problems determine a direction by solving a
		   quadratic programming subproblem. The global convergence
		   properties are addressed by using a line search technique
		   and a merit function to modify the length of the step
		   obtained from the quadratic program. In unconstrained
		   optimization, trust regions strategies have been very
		   successful. In this paper, we present a new approach for
		   equality constrained optimization problems based on a trust
		   region strategy. The direction selected is not necessarily
		   the solution of the standard quadratic programming
		   subproblem.},
 summary	= {As for \citebb{Celi85}.}}

@article{CesaAgreHelgJorgJens91,
 author		= {A. Cesar and H. Agren and T. Helgaker and P. Jorgensen and
		   H. J. A. Jensen},
 title		= {Excited-State Structures and Vibronic Spectra of
		   {H}$_2${CO}$_+$, {HDCO}$_+$, and {D}$_2${CO}$_+$ Using
		   Molecular Gradient and {H}essian Techniques},
 journal	= {Journal of Chemical Physics},
 volume		= 95, number = 8, pages = {5906--5917}, year = 1991,
 abstract	= {We choose H$_2$CO$_+$ and its deuterated species to
		   demonstrate the potential for using second-order
		   multiconfigurational self-consistent field theory to
		   optimize structures and calculate properties of ionized and
		   excited states. We focus on the calculation of
		   multidimensional vibronic spectra using only the local
		   information of the potential hypersurface, viz. the
		   molecular energy, gradient, and Hessian. Second-order
		   multiconfigurational self-consistent field optimization on
		   lowest excited states using the trust radius algorithm is
		   found to give the same stable convergence as for neutral
		   ground states, while for higher lying states, the problem
		   of multidimensional potential crossings renders the
		   calculations more difficult.},
 summary	= {H$_2$CO$_+$ and its deuterated species are chosen to
		   demonstrate the potential for using second-order
		   multiconfigurational self-consistent field theory to
		   optimize structures and calculate properties of ionized and
		   excited states. The focus is on calculation of
		   multidimensional vibronic spectra using only the
		   molecular energy, gradient, and Hessian of the potential
		   hypersurface. Second-order multiconfigurational
		   self-consistent field optimization on lowest excited states
		   using the trust-region algorithm is found to give the same
		   stable convergence as for neutral ground states. For higher
		   lying states, the problem of multidimensional potential
		   crossings renders the calculations more difficult.}}

@article{ChabCrou84,
 author		= {Y. Chabrillac and J.-P. Crouzeix},
 title		= {Definiteness and semidefiniteness of quadratic forms
		   revisited},
 journal	= LAA,
 volume		= 63, pages = {283--292}, year = 1984}

@article{ChamPoweLemaPede82,
 author		= {R. M. Chamberlain and M. J. D. Powell and C. Lemar\'{e}chal
		   and H. C. Pedersen},
 title		= {The watchdog technique for forcing convergence in
		   algorithms for constrained optimization},
 journal	= MPS,
 volume		= 16, number = {MAR}, pages = {1--17}, year = 1982}
% abstract	= {Han proves that a line search objective function, which is
%		   of a form that occurs in many algorithms for constrained
%		   optimization, can be used to force convergence to a
%		   Kuhn-Tucker point. We give an example, however, to show
%		   that this line search objective function can prevent a
%		   superlinear rate of convergence. If this situation occurs,
%		   we find that it is advantageous to replace the line search
%		   objective function by an estimate of the Lagrangian
%		   function. Therefore a technique is proposed, which chooses
%		   automatically between Han's line search function and the
%		   Lagrangian function, in a way that gives superlinear
%		   convergence. We call it the ``watchdog technique'', because
%		   the conditions on the step-length of a line search are
%		   restricted on some iterations by a monitor, in order to
%		   retain global convergence to a Kuhn-Tucker point from a
%		   poor initial estimate of the solution.},
% summary	= {\citebb{Han77} proved that a line search objective
%		   function, which is of a form that occurs in many algorithms
%		   for constrained optimization, can be used to force
%		   convergence to a Kuhn-Tucker point. An example is given
%		   which shows that this linesearch objective function can
%		   prevent a superlinear rate of convergence. If this
%		   situation occurs, it is advantageous to replace the line
%		   search objective function by an estimate of the Lagrangian
%		   function. Therefore a technique is proposed, which chooses
%		   automatically between Han's linesearch function and the
%		   Lagrangian function, in a way that gives superlinear
%		   convergence. This technique is known as the ``watchdog
%		   technique'', because the conditions on the step-length of a
%		   linesearch are restricted on some iterations by a monitor,
%		   in order to retain global convergence to a Kuhn-Tucker
%		   point from a poor initial estimate of the solution.}}

@article{ChanOlkiCool92,
 author  	= {T. F. Chan and J. A. Olkin and D. W. Cooley},
 title  	= {Solving quadratically constrained least squares using 
                   black box solvers},
 journal 	= BIT,
 volume  	= 32, pages = {481-495}, year = 1992}


@phdthesis{Chan78,
 author		= {R. Chandra},
 title		= {Conjugate gradient methods for partial differential
		   equations},
 school		= {Yale University}, address = {New Haven, USA},
 year		= 1978}

@article{ChanCott80,
 author 	= {Y. Y. Chang and R. W. Cottle},
 title  	= {Least-index resolution of degeneracy in quadratic
		   programming},
 journal 	= MP,
 volume 	= 18, number = 2, pages = {127--137}, year = 1980}

@article{Char78,
 author		= {C. Charalambous},
 title		= {A lower bound for the controlling parameter of the exact
		   penalty functions},
 journal	= MP,
 volume		= 15, number = 3, pages = {278--290}, year = 1978}

@article{Char79,
 author         = {C. Charalambous},
 title          = {Acceleration of the least $p$-th algorithm for minimax
                   optimization with engineering applications},
 journal        = MP, 
 volume         = 17, number = 1, pages = {270--297}, year = 1979}

@article{CharConn75,
 author         = {A. R. Conn and C. Charalambous},
 title          = {Optimization of Microwave Networks},
 journal        = {IEEE Transactions on Microwave Theory and Techniques},
 volume         = 23, number = 10, pages = {834--838}, year = 1975}

@inproceedings{Chen95,
 author         = {Z. Chen},
 title          = {A new trust region algorithm for optimization with 
                   simple bounds},
 booktitle      = {Operations Research and Its Applications. Proceedings of the
                   First International Symposium, ISORA '95}, 
 editor         = {D. Z. Du and X. S. Zhang and K. Cheng},
 publisher      = {Beijing World Publishing}, address = {Beijing, China},
 pages          = {49--58}, year = 1995,
 abstract       = {We present an algorithm of trust region type for
                   minimizing a differentiable function of many
                   variables with simple bounds. Under milder
                   conditions, we prove the global convergence of the
                   main algorithm. It is also proved that the correct
                   active set is identified in a finite number of
                   iterations with a strict complementarity condition,
                   and so the proposed algorithm reduces to an
                   unconstrained minimization method in a finite number
                   of iterations, allowing a fast asymptotic rate of
                   convergence.},
 summary        = {A globally convergent trust-region algorithm is presented for
                   minimizing a differentiable function of many
                   variables with simple bounds.It is proved that the correct
                   active set is identified in a finite number of
                   iterations under a strict complementarity condition,
                   allowing a fast asymptotic rate of convergence.}}

@incollection{Chen96,
 author         = {Z. Chen},
 title          = {Some algorithms for a class of CDT subproblems},
 booktitle      = {Lecture Notes in Operations Research},
 editor         = {D. Du and X. Zhang and W. Wang},
 publisher      = {Beijing World Publishing}, address = {Beijing, China},
 pages          = {108--114}, year = 1996}

@inproceedings{ChenDengZhan95,
 author         = {L. Chen and N. Deng and J. Zhang},
 title          = {A trust region method with partial-update technique for 
                   unary optimization},
 booktitle      = {Operations Research and Its Applications. Proceedings of the
                   First International Symposium, ISORA '95}, 
 editor         = {D. Z. Du and X. S. Zhang and K. Cheng},
 publisher      = {Beijing World Publishing}, address = {Beijing, China},
 pages          = {40--46}, year = 1995,
 abstract       = {We propose a modified partial-update algorithm for
                   solving unconstrained unary optimization problems
                   based on trust region stabilization via indefinite
                   dogleg curves. This algorithm only partially updates
                   an approximation to the Hessian matrix in each
                   iteration by utilizing limited times of rank-one
                   updating of Bunch-Parlett factorization. In contrast
                   with the original algorithms in \citebb{GoldWang93},
                   the algorithm not only converges globally,
                   but also possesses a locally quadratic convergence
                   rate. Furthermore, our numerical experiments show
                   that the new algorithm outperforms the trust region
                   method which uses the partial update criteria
                   suggested in the above paper.},
 summary        = {A modified partial-update algorithm for
                   solving unconstrained unary optimization problems
                   is proposed, based on trust-region stabilization via
		   indefinite dogleg curves. This algorithm only partially
		   updates an approximation to the Hessian matrix in each
                   iteration by applying a limited number of rank-one
                   updates to its  Bunch-Parlett factorization. In contrast
                   with the original algorithms proposed by \citebb{GoldWang93},
                   the algorithm not only converges globally,
                   but also possesses a locally quadratic convergence
                   rate. Furthermore,  numerical experiments show
		   improved performance.}}

@techreport{ChenChenKanz97,
 author		= {B. Chen and X. Chen and Ch. Kanzow},
 title		= {A penalized {F}ischer-{B}urmeister {NCP}-Function:
		   theoretical Investigation and Numerical Results },
 institution	= HAMBURG, address = HAMBURG-ADDRESS,
 number		= {A-126}, year = 1997}

@article{ChenDengZhan98,
 author		= {L. Chen and N. Deng and J. Zhang},
 title		= {Modified partial-update {N}ewton-type algorithms for unary
		   optimization},
 journal	= JOTA,
 volume		= 97, number = 2, pages = {385--406}, year = 1998,
 abstract	= {In this paper, we propose two modified partial-update
		   algorithms for solving unconstrained unary optimization
		   problems based on trust-region stabilization via indefinite
		   dogleg curves. The two algorithms partially update an
		   approximation to the Hessian matrix in each iteration by
		   utilizing a number of times the rank-one updating of the
		   Bunch-Parlett factorization. In contrast with earlier
		   algorithms, the two algorithms not only converge
		   globally, but possess also a locally quadratic or
		   superlinear convergence rate. Furthermore, our numerical
		   experiments show that the new algorithms outperform the
		   trust-region method which uses the partial update criteria
		   suggested in Ref. 1.},
 summary	= {Two modified partial-update algorithms for solving
		   unconstrained unary optimization problems based on
		   trust-region stabilization via indefinite dogleg curves are
		   proposed. They both partially update an approximation to
		   the Hessian matrix in each iteration by using 
		   the SR1 updating of the Bunch-Parlett factorization.
		   They converge globally with a locally quadratic or
		   superlinear convergence rate. Numerical experiments
		   indicate that they outperform the trust-region method which
		   uses some other partial update criteria.}}

@article{ChenHigh98,
 author		= {S. H. Cheng and N. J. Higham},
 title		= {A Modified {Cholesky} Algorithm Based on a Symmetric
		   Indefinite Factorization},
 journal	= SIMAA,
 volume		= 19, number = 4, pages = {1097--1110}, year = 1998}

 institution	= MCCM, address = MCCM-ADDRESS,
 type		= {Numerical Analysis Report}, number = {No. 289},
 year		= 1996}

@article{ChenHan96,
 author		= {Z. W. Chen and J. Y. Han},
 title		= {A trust region algorithm for optimization with nonlinear
		   equality and linear inequality constraints},
 journal	= {Science in China Series A --- Mathematics Physics Astronomy},
 volume		= 39, number = 8, pages = {799--806}, year = 1996,
 abstract	= {A new algorithm of trust region type is presented to
		   minimize a differentiable function of many variables with
		   nonlinear equality and linear inequality constraints. Under
		   the milder conditions, the global convergence of the main
		   algorithm is proved. Moreover, since any nonlinear
		   inequality constraint can be converted into an equation by
		   introducing a slack variable, the trust region method can
		   be used in solving general nonlinear programming problems.},
 summary	= {A globally convergent trust-region algorithm is presented
		   to minimize a smooth function of many variables with
		   nonlinear equality and linear inequality constraints.}}

@article{ChenMang96,
 author		= {C. Chen and O. L. Mangasarian},
 title		= {A class of smoothing functions for nonlinear and mixed
		   complementarity problems},
 journal	= COAP,
 volume		= 5, number = 2, pages = {97--138}, year = 1996}

@article{ChenSyku96,
 author		= {Y. B. Cheng and J. K. Sykulski},
 title		= {Automated design and optimization of electromechanical
		   actuators},
 journal	= {International Journal of Numerical Modelling-Electronic
		   Networks Devices and Fields},
 volume		= 9, number = {1--2}, pages = {59--69}, year = 1996,
 abstract	= {The paper investigates various optmization techniques and
		   their suitability for the magnetic design of
		   electromechanical actuators. Selected algorithms, including
		   Gauss-Newton, \citebb{Leve44}--\citebb{Marq63} and Trust
		   region, are examined and compared using 18 test functions.
		   The Levenberg-Marquardt method is chosen for its robustness
		   and fast convergence, and incorporated into an automated
		   CAD optimization system (EAMON), which interfaces an
		   external optimizer to a general purpose finite element
		   package; The EAMON program, which is user friendly with
		   pull-down menus, searches for constrained shape design
		   variables that fulfill prescribed performance criteria. The
		   electromagnetic field analysis forms part of the
		   optimization iterative cycle. Finally, two application
		   examples are described. First, a DC solenoid actuator with
		   truncated cone pole face is optimized to produce a user
		   specified force-displacement characteristic. Secondly, an
		   actuator solenoid is optimized to produce maximum energy
		   per stroke.},
 summary	= {The suitability of various optimization techniques for the
		   magnetic design of electromechanical actuators is examined.
		   The Gauss-Newton, Levenberg-Morrison-Marquardt and
		   trust-region algorithms are compared using 18 test
		   functions. The Levenberg-Morrison-Marquardt method is
		   chosen for its robustness and fast convergence, and
		   incorporated into an automated CAD optimization system
		   (EAMON), which interfaces an external optimizer to a
		   general purpose finite element package. The user-friendly
		   EAMON program searches for constrained shape design
		   variables that fulfill prescribed performance criteria. The
		   electromagnetic field analysis forms part of the
		   optimization iterative cycle. As examples, a DC solenoid
		   actuator with truncated cone pole face is optimized to
		   produce a user-specified force-displacement characteristic,
		   and an actuator solenoid is optimized to produce maximum
		   energy per stroke.}}

@article{ChenYuan99,
 author         = {X. D. Chen and Y. Yuan},
 title          = {On local solutions of the CDT subproblem},
 journal        = SIOPT,
 note           = {To appear.}, year = 1999,
 abstract       = {In this paper, we discuss the distribution of the local
                   solutions of the CDT subproblem which appears in some
                   trust region algorithms for nonlinear optimization.   We
                   also give some examples to show the differences between the
                   CDT subproblem and the single-ball constraint subproblem.
                   These results show that the complexity of the CDT subproblem
                   does not depend on the complexity of the structure of the
                   dual plane, thus they provide the possibility to search the
                   global minimizer in the dual plane.},
 summary        = {The distribution of the local solutions of the CDT
                   subproblem which appears in some trust region algorithms for
                   nonlinear optimization is discussed.  Examples illustrate the
                   differences between the CDT subproblem and the single-ball
                   constraint subproblem. The complexity of the CDT subproblem
                   is shown not to depend on the complexity of the structure
                   of the dual plane, which opens the possibility of searching
                   the global minimizer in this plane.}}

@techreport{ChinFlet99,
 author         = {C. M. Chin and R. Fletcher},
 title          = {Convergence Properties of SLP-filter Algorithms that
                   use EQP steps},
 institution    = DUNDEE, address = DUNDEE-ADDRESS,
 type           = {Numerical Analysis Report},
 number         = {(in preparation)}, year = 1999}

@inproceedings{ChowChen94,
 author         = {T. T. Chow and P. K. Chen},
 title          = {A new trust region global strategy for unconstrained 
                   optimization},
 booktitle      = {1994 International Computer Symposium Conference Proceedings.
                   National Chiao Tung University, Hsinchu, Taiwan},
 volume         = 1, pages = {394--401}, year = 1994,
 abstract       = {This paper introduces a new global strategy, the
                   tensor dogleg method, for solving unconstrained
                   optimization problems, especially using tensor
                   methods. Tensor methods for unconstrained
                   optimization were first introduced by R.B. Schnabel
                   and T.T. Chow (1991). They adopted line search method
                   and two trust region methods as global strategies,
                   but these trust region methods were either
                   inefficient or too complicated. Therefore, the
                   software package, TENMIN, developed by T.T. Chow et
                   al. employed only the line search method as the
                   global strategy for the tensor methods. We tested
                   several different versions of our tensor dogleg
                   algorithm. Although the performance of each version
                   of the algorithm differed slightly, most of them
                   performed better than TENMIN. The final version of
                   the tensor dogleg algorithm comprises eleven
                   states. During our tests we found that the candidate
                   steps generated by our algorithm were in the tensor
                   step directions more often than in other
                   directions. The test results indicate that our tensor
                   dogleg algorithm performs better than not only the
                   standard double dogleg algorithm with Newton steps
                   but also the conventional line search method using
                   tensor steps.},
 summary        = {This paper introduces the tensor dogleg method, a
		   trust-region technique for solving unconstrained
                   optimization problems, which seems to outperform the 
		   linesearch based TENMIN package.}}

@book{Chva83, 
 author  	= {V. Chv\'{a}tal},
 title   	= {Linear Programming},
 publisher 	= FREEMAN, address = FREEMAN-ADDRESS,
 year    	= 1983}

@book{Clar83,
 author		= {F. H. Clarke},
 title		= {Optimization and Nonsmooth Analysis},
 publisher	= WILEY, address = WILEY-ADDRESS,
 series		= {Canadian Mathematical Society series in mathematics},
 year		= 1983,
 note           = {Reprinted as \emph{Classics in Applied Mathematics 5}, SIAM,
		   Philadelphia, USA, 1990}}

@article{ClerDelaPhamYass91,
 author		= {J. R. Clermont and M. E. Delalande and Pham Dinh, T. and A.
		   Yassine},
 title		= {Analysis of Plane and Axisymmetrical Flows of
		   Incompressible Fluids with the Steam Tube 
                   Method---Numerical-Simulation by Trust-Region Optimization
                   Algorithm},
 journal	= {International Journal for Numerical Methods in Fluids},
 volume		= 13, number = 3, pages = {371--399}, year = 1991,
 abstract	= {New concepts for the study of incompressible plane or
		   axisymmetric flows are analysed by the stream tube method.
		   Flows without eddies and pure vortex flows are considered
		   in a transformed domain where the mapped streamlines are
		   rectilinear or circular. The transformation between the
		   physical domain and the computational domain is an unknown
		   of the problem. In order to solve the non-linear set of
		   relevant equations, we present a new algorithm based on a
		   trust region technique which is effective for non-convex
		   optimization problems. Experimental results show that the
		   new algorithm is more robust compared to the Newton-Raphson
		   method.},
 summary	= {Concepts for the study of incompressible plane or
		   axisymmetric flows are analysed by the stream tube method.
		   Flows without eddies and pure vortex flows are considered
		   in a transformed domain where the mapped streamlines are
		   rectilinear or circular. The transformation between the
		   physical domain and the computational domain is an unknown
		   of the problem. A trust-region algorithm is given for
		   solving the relevant nonlinear set of equations,
		   Experimental results show that it is more robust than the
		   Newton-Raphson method.}}

@inproceedings{ClinConnVanL82,
 author		= {A. K. Cline and A. R. Conn and Van Loan, C. F.},
 title		= {Generalizing the {LINPACK} condition estimator},
 crossref	= {Henn82}, pages = {73--83}}

@article{ClinMoleStewWilk79,
 author		= {A. K. Cline and C. B. Moler and G. W. Stewart and J. H.
		   Wilkinson},
 title		= {An estimate for the condition number of a matrix},
 journal	= SINUM,
 volume		= 16, pages = {368-375}, year = 1979}

@inproceedings{Cole94,
 author		= {T. F. Coleman},
 title		= {Linearly Constrained Optimization and Projected
		   Preconditioned Conjugate Gradients},
 booktitle	= {Proceedings of the Fifth SIAM Conference on Applied Linear
		   Algebra},
 editor		= {J. Lewis},
 publisher	= SIAM, address = SIAM-ADDRESS,
 pages		= {118--122}, year = 1994}

@article{ColeConn80,
 author		= {T. F. Coleman and A. R. Conn},
 title		= {Second-order conditions for an exact penalty function},
 journal	= MP,
 volume		= 19, number = 2, pages = {178--185}, year = 1980}

@article{ColeConn82,
 author		= {T. F. Coleman and A. R. Conn},
 title		= {Non-linear programming via an exact penalty-function:
		   asymptotic analysis},
 journal	= MP,
 volume		= 24, number = 2, pages = {123--136}, year = 1982}
 

@article{ColeConn82b,
 author		= {T. F. Coleman and A. R. Conn},
 title		= {Non-linear programming via an exact penalty-function:
		   global analysis},
 journal	= MP,
 volume		= 24, number = 2, pages = {137--161}, year = 1982}

@article{ColeFeny92,
 author		= {T. F. Coleman and P. A. Fenyes},
 title		= {Partitioned quasi-{N}ewton methods for nonlinear equality
		   constrained optimization},
 journal	= MP,
 volume		= 53, number = 1, pages = {17--44}, year = 1992}
 
@article{ColeHemp90,
 author		= {T. F. Coleman and C. Hempel},
 title		= {Computing a trust region step for a penalty function},
 journal	= SISSC,
 volume		= 11, number = 1, pages = {180--201}, year = 1990,
 abstract	= {The problem of minimizing a quadratic function subject to
		   an ellipsoidal constraint when the matrix involved is the
		   Hessian of a penalty function (i.e., a function of the form
		   $p(x)=f(x)+(1/2\mu)c(x)^Tc(x)$) is considered. Most
		   applications of penalty functions require $p(x)$ to be
		   minimized for values of $\mu$ decreasing to zero. In
		   general, as $\mu$ tends to zero the nature of finite
		   precision arithmetic causes a considerable loss of
		   information about the null space of the constraint
		   gradients when $\nabla^2p(x)$ is formed. This loss of
		   information renders ordinary trust region Newton's method
		   unstable and degrades the accuracy of the solution to the
		   trust region problem. The algorithm of \citebb{MoreSore83}
		   is modified so as to be more stable and less sensitive to
		   the nature of finite precision arithmetic in this
		   situation. Numerical experiments clearly demonstrate the
		   stability of the proposed algorithm.},
 summary	= {The minimization of a quadratic function subject to
		   an ellipsoidal constraint is considered in the case when
		   the matrix involved is the Hessian of a penalty function
		   $p(x)=f(x)+(1/2\mu)c(x)^Tc(x)$. Most applications
		   require $p(x)$ to be minimized for values
		   of $\mu$ decreasing to zero. The algorithm of
		   \citebb{MoreSore83} is modified so as to be less sensitive
		   to the nature of finite precision arithmetic in this
		   situation. Numerical experiments illustrate the stability
		   of the modified algorithm.}}

@article{ColeHulb89,
 author		= {T. F. Coleman and L. A. Hulbert},
 title		= {A direct active set algorithm for large sparse quadratic
		   programs with simple bounds},
 journal	= MPB,
 volume		= 45, number = 3, pages = {373--406}, year = 1989}

@article{ColeHulb93,
 author		= {T. F. Coleman and L. A. Hulbert},
 title		= {A Globally and Superlinearly Convergent Algorithm for
		   Convex Quadratic Programs with Simple Bounds},
 journal	= SIOPT,
 volume		= 3, number = 2, pages = {298--321}, year = 1993}
 abstract	= {We present a globally and superlinearly convergent
		   algorithm for solving convex quadratic programs with simple
		   bounds. We develop our algorithm using a new formulation of
		   the problem: the minimization of an unconstrained piecewise
		   quadratic function that has the same optimality conditions
		   as the original problem. The major work at each iteration
		   is the Cholesky factorization of a positive definite matrix
		   with the size and structure of the Hessian of the
		   quadratic. Hence our algorithm is suitable for solving
		   large-scale problems and for implementation on parallel
		   computers. We implemented our algorithm and tested it on a
		   sequential computer on a variety of dense problems, and we
		   present numerical results which show that our algorithm
		   solves many problems quickly.},
 summary	= {A globally and superlinearly convergent algorithm for
		   solving convex quadratic programs with simple bounds is
		   given. It uses the minimization
		   of an unconstrained piecewise quadratic function that has
		   the same optimality conditions as the original problem.
		   The major work at each iteration is the Cholesky
		   factorization
		   of a positive definite matrix with the size and structure of
		   the Hessian of the quadratic. Hence the algorithm is suitable
		   for solving large-scale problems and for implementation on
		   parallel computers. An implementation of the algorithm is
		   tested on a sequential computer using a variety of dense
		   problems. Numerical results are presented.}}

@article{ColeLi94,
 author		= {T. F. Coleman and Y. Li},
 title		= {On the convergence of interior-reflective {N}ewton methods
		   for nonlinear minimization subject to bounds},
 journal	= MP,
 volume		= 67, number = 2, pages = {189--224}, year = 1994}
 
@article{ColeLi96,
 author		= {T. F. Coleman and Y. Li},
 title		= {A Reflective {N}ewton Method for Minimizing a Quadratic
		   Function Subject to Bounds on Some of the Variables},
 journal	= SIOPT,
 volume		= 6, number = 4, pages = {1040--1058}, year = 1996,
 abstract	= {We propose a new algorithm, a reflective Newton method, for
		   the minimization of a quadratic function of many variables
		   subject to upper and lower bounds on some of the variables.
		   The method applies to a general (indefinite) quadratic
		   function for which a local minimum subject to bounds is
		   required and is particularly suitable for the large-scale
		   problem. Our new method exhibits strong convergence
		   properties and global and second-order convergence and
		   appears to have significant practical potential. Strictly
		   feasible points are generated. We provide experimental
		   results on moderately large and sparse problems based on
		   both sparse Cholesky and preconditioned conjugate gradient
		   linear solvers.},
 summary	= {A reflective Newton method is proposed for the minimization
		   of a quadratic function of many variables subject to upper
		   and lower bounds on some of the variables. It applies to a
		   general (indefinite) quadratic function for which a local
		   minimum subject to bounds is required and is particularly
		   suitable for the large-scale problem. The method is
		   globally and asymptotically quadratically convergent.
		   generates strictly feasible points. Experimental results
		   are presented for moderately large and sparse problems
		   based on both sparse Cholesky and preconditioned
		   conjugate-gradient linear solvers.}}

@article{ColeLi96b,
 author		= {T. F. Coleman and Y. Li},
 title		= {An Interior Trust Region Approach for Nonlinear
		   Minimization Subject to Bounds},
 journal	= SIOPT,
 volume		= 6, number = 2, pages = {418--445}, year = 1996,
 abstract	= {We propose a new trust region approach for minimizing a
		   nonlinear function subject to simple bounds. Unlike most
		   existing methods, our proposed method does not require that
		   a quadratic programming subproblem, with inequality
		   constraints, be solved each iteration. Instead, a solution
		   to a trust region subproblem is defined by minimizing a
		   quadratic function subject only to an ellipsoidal
		   constraint. The iterates generated are strictly feasible.
		   Our proposed method reduces to a standard trust region
		   approach for the unconstrained problem when there are no
		   upper or lower bounds on the variables. Global and local
		   quadratic convergence is established. Preliminary numerical
		   experiments are reported indicating the practical viability
		   of this approach.},
 summary	= {A trust-region approach for minimizing a nonlinear function
		   subject to simple bounds is proposed, that does not require
		   that a quadratic programming subproblem with inequality
		   constraints be solved every iteration. Instead, a solution
		   to a trust-region subproblem is sought. The iterates
		   generated are strictly feasible. The proposed method reduces
		   to a standard trust-region approach for the unconstrained
		   problem. Global and locally quadratic convergence is
		   established. Preliminary numerical experiments are reported.}}

@techreport{ColeLi97b,
 author		= {T. F. Coleman and Y. Li},
 title		= {A trust region and affine scaling interior point method for
		   nonconvex minimization with linear inequality constraints},
 institution	= CS-CORNELL, address = CORNELL-ADDRESS,
 number		= {TR 97-1642}, year = 1997,
 abstract	= {A trust region and affine scaling interior point method
		   (TRAM) is proposed for a general nonlinear minimization
		   with linear inequality constraints by \citebb{ColeLi98}. In
		   the proposed approach, a Newton step is derived from the
		   complementarity conditions. Based on this Newton step, a
		   trust region subproblem is formed, and the original
		   objective function is monotonically decreased. Explicit
		   sufficient decrease conditions are proposed for satisfying
		   complementarity, dual feasibility and second order
		   optimality. The objective of this paper is to establish
		   global and local convergence properties of the proposed
		   trust region and affine scaling interior point method. It
		   is shown that the proposed decrease conditions are
		   sufficient for achieving complementarity, dual feasibility
		   and second order optimality respectively. It is also
		   established that a trust region solution is asymptotically
		   in the interior of the proposed trust region subproblem and
		   a damped trust region step can achieve quadratic
		   convergence.},
 summary	= {Global and local convergence properties of the trust-region
		   and affine-scaling interior-point method (TRAM) by
		   \citebb{ColeLi98} are established. It is shown that a
		   trust-region solution is asymptotically in the interior of
		   the trust region subproblem and a damped trust-region step
		   can achieve quadratic convergence.}}

@inproceedings{ColeLi98,
 author		= {T. F. Coleman and Y. Li},
 title		= {Combining trust region and affine scaling for linearly
		   constrained nonconvex minimization},
 crossref	= {Yuan98}, pages = {219--250},
 abstract	= {An interior point method is proposed for a general
		   nonlinear (non-convex) minimization with linear inequality
		   constraints. This method is a combination of the trust
		   region idea for nonlinearity and affine scaling technique
		   for constraints. Using this method, the original objective
		   function is monotonically decreased. In the proposed
		   approach, a Newton step is derived directly from the
		   complementarity conditions. A trust region subproblem is
		   formed which yields an approximate Newton step as its
		   solution asymptotically. The objective function of the
		   trust region subproblem is the quadratic approximation to
		   the original objective function plus an augmented quadratic
		   convex term. Similar to an augmented Lagrangian function,
		   this augmentation adds positive curvature in the range
		   space of the constraint normals. The global convergence is
		   achieved by possibly using trust regions with different
		   shapes. A reflection technique, which accelerates
		   convergence, is described. Explicit sufficient decrease
		   conditions are proposed. Computational results of a
		   two-dimensional trust region implementation are reported
		   for large-scale problems. Preliminary experiments suggest
		   that this method can be effective; a relatively small
		   number of function evaluations are required for some medium
		   and large test problems.},
 summary	= {An interior-point method is proposed for
		   non-convex minimization with linear inequality
		   constraints. It combines the trust-region idea for
		   nonlinearity and affine-scaling technique for constraints,
		   and ensures that the original objective function is
		   monotonically decreased. A subproblem is formed which
		   asymptotically yields an approximate Newton step, directly
		   derived from the complementarity conditions. Global
		   convergence is achieved by possibly using trust regions
		   with different shapes. A reflection technique accelerates
		   convergence. Explicit sufficient decrease conditions are
		   proposed. Computational results of a two-dimensional
		   implementation are reported for large-scale problems.}}

@misc{ColeLi98b,
 author		= {T. F. Coleman and Y. Li},
 title		= {A primal-dual Trust Region Algorithm for Nonconvex
		   Programming using a $\ell_1$ Penalty Function},
 howpublished	= {Presentation at the Optimization 98 Conference, Coimbra},
 year		= 1998,
 abstract	= {A primal and dual algorithm is proposed for nonconvex
		   programming. Primal and dual steps are derived directly
		   from the complementarity conditions. A primal step is used
		   to yield decrease for the $\ell_1$ penalty function. In
		   addition, a dual step yields decrease for an appropriate
		   function of dual variables. Reflection procedures are used
		   to accelerate convergence and preliminary computational
		   results are reported.},
 summary	= {A primal-dual algorithm is proposed for non-convex
		   programming. Primal and dual steps are derived directly
		   from the complementarity conditions. A primal trust-region
		   step is used to yield decrease for the $\ell_1$ penalty
		   function, and a dual constrained least-squares step yields
		   decrease for an appropriate function of dual variables.
		   Reflection procedures are used to accelerate convergence
		   and preliminary computational results are reported.}}

@article{ColeLiao95,
 author         = {T. F. Coleman and A. Liao},
 title          = {An efficient trust region method for unconstrained 
                   discrete-time optimal control problem},
 journal        = COAP,
 volume         = 4, number = 1, pages = {47--66}, year = 1995,
 abstract	= {Discrete-time optimal control (DTOC) problems are
		   large-scale optimization problems with a dynamic structure.
		   In previous work this structure has been exploited to
		   provide very fast and efficient local procedures. Two
		   examples are the differential dynamic programming algorithm
		   (DDP) and the stagewise Newton procedure---both require
		   only $O(N)$ operations, where $N$ is the number of
		   timesteps. Both exhibit a quadratic convergence rate.
		   However, most algorithms in this category do not have a
		   satisfactory global convergence strategy. The most popular
		   global strategy is shifting: this sometimes works poorly
		   due to the lack of automatic adjustment to the shifting
		   element. In this paper we propose a method that
		   incorporates the trust region idea with the local stagewise
		   Newton's method. This method possesses advantages of both
		   the trust region idea and the stagewise Newton's method,
		   i.e., our proposed method has strong global and local
		   convergence properties yet remains economical. Preliminary
		   numerical results are presented to illustrate the behavior
		   of the proposed algorithm. We also collect in the Appendix
		   some DTOC problems that have appeared in the literature.},
 summary	= {A method is proposed that incorporates the trust-region
		   idea with the local stagewise Newton's method for
		   discrete-time optimal control (DTOC) problems. This method
		   has strong global and local convergence properties yet
		   remains economical. Preliminary numerical results
		   illustrate the behaviour of the algorithm. Some DTOC
		   problems that have appeared in the literature are collected
		   in appendix.}}

@article{ColeLiu99,
 author         = {T. F. Coleman and J. Liu},
 title          = {An interior {N}ewton method for quadratic programming},
 journal        = MPA,
 volume         = 85, number = 3, pages = {491--524}, year = 1999,
 abstract       = {We propose a new (interior) approach for the general
                   quadratic programming problem.  We establish that the
                   new method has strong convergence properties: the
                   generated sequence converges globally to a point
                   satisfying the second-order necessary optimality
                   conditions, and the rate of convergence is 2-step
                   quadratic if the limit point is a strong minimizer.
                   Published alternative interior approaches do not share
                   such strong convergence properties for the nonconvex case.
                   We also report on the results of preliminary numerical
                   experiments: the results indicate that the proposed method
                   has considerable practical potential.},
 summary        = {An interior point method is proposed for the general 
                   quadratic programming problem. The method converges
                   globally to a point satisfying the second-order necessary
                   optimality conditions, and the rate of convergence is
                   2-step quadratic if the limit point is a strong minimizer.
                   Preliminary numerical experiments indicate that the method
                   has practical potential.}}

@article{ColeMore83,
 author		= {T. F. Coleman and J. J. Mor\'{e}},
 title		= {Estimation of sparse {J}acobian matrices and graph coloring
		   problems},
 journal	= SINUM,
 volume		= 20, pages = {187--209}, year = 1983}

@article{ColeMore84,
 author		= {T. F. Coleman and J. J. Mor\'{e}},
 title		= {Estimation of sparse {H}essian matrices and graph coloring
		   problems},
 journal	= MP,
 volume		= 28, pages = {243--270}, year = 1984}

@article{ColePlas92,
 author		= {T. F. Coleman and P. E. Plassman},
 title		= {A Parallel Nonlinear Least-Squares Solver--Theoretical
		   Analysis and Numerical Results},
 journal	= SISSC,
 volume		= 13, number = 3, pages = {771--793}, year = 1992,
 abstract       = {The authors (1989) proposed a parallel algorithm,
                   based on the sequential Levenberg-Marquardt method
                   for the nonlinear least-squares problem. The
                   algorithm is suitable for message-passing
                   multiprocessor computers. A parallel efficiency
                   analysis is provided and computational results are
                   reported. The experiments were performed on an Intel
                   iPSC/2 multiprocessor with 32 nodes: the paper
                   presents experimental results comparing the given
                   parallel algorithm with sequential MINPACK code
                   executed on a single processor. These experimental
                   results show that essentially full efficiency is
                   obtained for problems where the row size is
                   sufficiently larger than the number of processors.},
 summary	= {The paper presents experimental results comparing a
                   parallel version of the Levenberg-Morrison-Marquardt
		   algorithm on  an Intel iPSC/2 multiprocessor with 32
		   nodes with sequential MINPACK code executed on a single
		   processor. These experimental results show that essentially
		   full efficiency is obtained for problems where the row 
                   size is sufficiently larger than the number of processors.}}

@article{ColePoth86a,
 author		= {T. F. Coleman and A. Pothen},
 title		= {The Null Space Problem {I}: complexity},
 journal	= SIADM,
 volume		= 7, number = 4, pages = {527-537}, year = 1986}

@article{ColePoth87,
 author		= {T. F. Coleman and A. Pothen},
 title		= {The Null Space Problem {II}: algorithms},
 journal	= SIADM,
 volume		= 8, number = 4, pages = {544-563}, year = 1987}

@article{ColeSore84,
 author		= {T. F. Coleman and D. C. Sorensen},
 title		= {A note on the computation of an orthonormal basis for the
		   null space of a matrix},
 journal	= MP,
 volume		= 29, number = 2, pages = {234--242}, year = 1984}
 
@techreport{ColeYuan95,
 author		= {T. F. Coleman and W. Yuan},
 title		= {A New Trust Region Algorithm for Equality Constrained
		   Optimization},
 institution	= CS-CORNELL, address = CORNELL-ADDRESS,
 number		= {TR95-1477}, year = 1995,
 abstract	= {We present a new trust region algorithm for solving
		   nonlinear equality constrained optimization problems. At
		   each iterate a change of variables is performed to improve
		   the ability of the algorithm to follow the constraint level
		   sets. The algorithm employs $L_2$ penalty functions for
		   obtaining global convergence. Under certain assumptions we
		   prove that this algorithm globally converges to a point
		   satisfying the second order necessary conditions; the local
		   convergence rate is quadratic. Results of preliminary
		   numerical experiments are presented.},
 summary	= {A trust-region algorithm for solving nonlinear equality
		   constrained problems is presented. At each
		   iterate a change of variables improves the
		   ability of the algorithm to follow the constraint level
		   sets. The algorithm employs quadratic penalty functions to
		   obtain global convergence. It converges globally and 
		   Q-quadratically to a point satisfying second-order
		   necessary optimality conditions. Preliminary numerical
		   experiments are presented.}}

@book{Coll66,
 author		= {L. Collatz},
 title		= {Functional Analysis and Numerical Mathematics},
 publisher	= AP, address = AP-ADDRESS,
 year		= 1966}

@mastersthesis{Cols99,
 author         = {B. Colson},
 title          = {Mathematical Programs with Equilibrium Constraints and
                   Nonlinear Bilevel Programming Problems},
 school         = FUNDP, address = FUNDP-ADDRESS,
 year           = 1999}

@inproceedings{ConcGoluOLea76,
 author		= {P. Concus and G. H. Golub and D. P. O'Leary},
 title		= {Numerical Solution of Nonlinear Elliptic Partial
		   Differential Equations by a Generalized Conjugate Gradient
		   Method},
 booktitle	= {Sparse Matrix Computations},
 editor		= {J. Bunch and D. Rose},
 publisher	= AP, address = AP-ADDRESS,
 pages		= {309--332}, year = 1976}

@article{Conn73,
 author		= {A. R. Conn},
 title		= {Constrained optimization via a nondifferentiable penalty
		   function},
 journal	= SINUM,
 volume		= 10, number = 4, pages = {760--779}, year = 1973}

@inproceedings{ConnCoulHariMoriVisw96,
 author		= {A. R. Conn and P. K. Coulman and R. A. Haring and G. L.
		   Morrill and C. Visweswariah},
 title		= {Optimization of custom {MOS} circuits by transistor sizing},
 booktitle	= {IEEE/ACM International Conference on Computer-Aided Design.
		   Digest of Technical Papers (Cat. No.96CB35991)},
 publisher	= {IEEE},
 address	= {IEEE Comput. Soc. Press, Los Alamitos, USA},
 pages		= {p.174--180}, year = 1996,
 abstract	= {Optimization of a circuit by transistor sizing is often a
		   slow, tedious and iterative manual process which relies on
		   designer intuition. Circuit simulation is carried out in
		   the inner loop of this tuning procedure. Automating the
		   transistor sizing process is an important step towards
		   being able to rapidly design high-performance, custom
		   circuits. JiffyTune is a new circuit optimization tool that
		   automates the tuning task. Delay, rise/fall time, area and
		   power targets are accommodated. Each (weighted) target can
		   be either a constraint or an objective function. Minimax
		   optimization is supported. Transistors can be ratioed and
		   similar structures grouped to ensure regular layouts.
		   Bounds on transistor widths are supported. JiffyTune uses
		   {\sf LANCELOT}, a large-scale nonlinear optimization
		   package with an augmented Lagrangian formulation. Simple
		   bounds are handled explicitly and trust region methods are
		   applied to minimize a composite objective function. In the
		   inner loop of the optimization, the fast circuit simulator
		   SPECS is used to evaluate the circuit. SPECS is unique in
		   its ability to efficiently provide time-domain
		   sensitivities, thereby enabling gradient-based
		   optimization. Both the adjoint and direct methods of
		   sensitivity computation have been implemented in SPECS. To
		   assist the user, interfaces in the Cadence and SLED design
		   systems have been constructed.},
 summary	= {JiffyTune is a circuit optimization tool that automates the
		   tuning task. Delay, rise/fall time, area and power targets
		   are accommodated. Each (weighted) target can be either a
		   constraint or an objective function. Minimax optimization
		   is supported. Transistors can be ratioed and similar
		   structures grouped to ensure regular layouts. Bounds on
		   transistor widths are supported. JiffyTune uses {\sf
		   LANCELOT}. In the inner loop of the optimization, the fast
		   circuit simulator SPECS is used to evaluate the circuit.
		   SPECS is unique in its ability to provide time-domain
		   sensitivities, thereby enabling gradient-based
		   optimization. Both the adjoint and direct methods of
		   sensitivity computation have been implemented in SPECS.
		   Interfaces in the Cadence and SLED design systems have been
		   constructed.}}

@inproceedings{ConnGoulLescToin94,
 author		= {A. R. Conn and N. I. M. Gould and M. Lescrenier and Ph. L.
		   Toint},
 title		= {Performance of a multifrontal scheme for partially
		   separable optimization},
 crossref	= {GomeHenn94}, pages = {79--96}}
%abstract       = {We consider the solution of partially separable
%                  minimization problems subject to simple bounds
%                  constraints. At each iteration, a quadratic model is used
%                  to approximate the objective function within a trust
%                  region. To minimize this model, the iterative method of
%                  conjugate gradients has usually been used. The aim of this
%                  paper is to compare the performance of a direct method, a
%                  multifrontal scheme, with the conjugate gradient method
%                  (with and without preconditioning). To assess our
%                  conclusions, a set of numerical experiments, including
%                  large-dimensional problems, is presented.}
        
@article{ConnGoulToin88a,
 author		= {A. R. Conn and N. I. M. Gould and Ph. L. Toint},
 title		= {Global convergence of a class of trust region algorithms
		   for optimization with simple bounds},
 journal	= SINUM,
 volume		= 25, number = 182, pages = {433--460}, year = 1988,
 note		= {See also same journal 26:764--767, 1989.},
 abstract	= {This paper extends the known excellent global convergence
		   properties of trust-region algorithms for unconstrained
		   optimization to the case where bounds on the variables are
		   present. Weak conditions on the accuracy of the Hessian
		   approximations are considered. It is also shown that, when
		   the strict complementarity condition holds, the proposed
		   algorithms reduce to an unconstrained calculation after
		   finitely many iterations, allowing a fast rate of
		   convergence.},
 summary	= {The global convergence properties of trust-region
		   algorithms for unconstrained optimization are extended to
		   the case where bounds on the variables are present. Weak
		   conditions on the accuracy of the Hessian approximations
		   are considered. When the strict complementarity condition
		   holds, the proposed algorithms reduce to an unconstrained
		   calculation after finitely many iterations, allowing fast
		   convergence.}}

@article{ConnGoulToin88b,
 author		= {A. R. Conn and N. I. M. Gould and Ph. L. Toint},
 title		= {Testing a class of methods for solving minimization
		   problems with simple bounds on the variables},
 journal	= MC,
 volume		= 50, pages = {399--430}, year = 1988,
 abstract	= {We describe the results of a series of tests upon a class
		   of new methods of trust region type for solving the simple
		   bound constrained minimization problem. The results are
		   encouraging and lead us to believe that the method will
		   prove useful in solving large problems.},
 summary	= {The results of tests on the trust-region methods proposed by
                   \citebb{ConnGoulToin88a} for solving the bound constrained
		   minimization problem are discussed.}}

@inproceedings{ConnGoulToin89b,
 author		= {A. R. Conn and N. I. M. Gould and Ph. L. Toint},
 title		= {An introduction to the structure of large scale nonlinear
		   optimization problems and the {{\sf LANCELOT}} project},
 booktitle	= {Computing Methods in Applied Sciences and Engineering},
 editor		= {R. Glowinski and A. Lichnewsky},
 publisher	= SIAM, address = SIAM-ADDRESS,
 pages		= {42--51}, year = 1990}
%abstract       = {This paper presents the authors' personal views on two
%                  fundamental aspects amongst the recent developments in the
%                  growing field of large-scale nonlinear mathematical
%                  programming. Important concepts for the description of
%                  problem structure are discussed in detail. A systematic
%                  approach to software development for this class of
%                  problems is also presented. The approach incorporates both
%                  suitable numerical algorithms and user oriented standard
%                  format for problem specification in a modular and coherent
%                  system.}

@article{ConnGoulToin91,
 author		= {A. R. Conn and N. I. M. Gould and Ph. L. Toint},
 title		= {A Globally Convergent Augmented {L}agrangian Algorithm for
		   Optimization with General Constraints and Simple Bounds},
 journal	= SINUM,
 volume		= 28, number = 2, pages = {545--572}, year = 1991}

@article{ConnGoulToin91a,
 author		= {A. R. Conn and N. I. M. Gould and Ph. L. Toint},
 title		= {Convergence of quasi-{N}ewton matrices generated by the
		   Symmetric Rank One update},
 journal	= MP,
 volume		= 50, number = 2, pages = {177--196}, year = 1991}

@inproceedings{ConnGoulToin91e,
 author		= {A. R. Conn and N. I. M. Gould and Ph. L. Toint},
 title		= {On the number of inner iterations per outer iteration of a
		   globally convergent algorithm for optimization with general
		   nonlinear equality constraints and simple bounds},
 crossref	= {GrifWats92}, pages = {49--68}}

@book{ConnGoulToin92,
 author		= {A. R. Conn and N. I. M. Gould and Ph. L. Toint},
 title		= {{\sf LANCELOT}: a {F}ortran package for Large-scale
		   Nonlinear Optimization ({R}elease {A})},
 publisher	= SPRINGER, address = SPRINGER-ADDRESS,
 series		= {Springer Series in Computational Mathematics}, year = 1992}

@techreport{ConnGoulToin92g,
 author		= {A. R. Conn and N. I. M. Gould and Ph. L. Toint},
 title		= {Intensive numerical tests with {{\sf LANCELOT}} ({R}elease
		   {A}): the complete results},
 institution	= FUNDP, address = FUNDP-ADDRESS,
 number		= {92/15}, year = 1992,
 note		= {Also issued as Research Report RC 18750, IBM T.J. Watson
		   Center, Yorktown Heights, USA, and as Research Report
		   92-069, RAL, Chilton, Oxfordshire, England},
 abstract	= {This report contains the detailed results of the numerical
		   experiments on the {\sf LANCELOT} package for nonlinear
		   optimization (Release A). These results constitute the
		   basis of the discussion and analysis presented by the
		   authors in \citebb{ConnGoulToin96a}.},
 summary	= {The detailed results for the tests reported by
		   \citebb{ConnGoulToin96a} are presented.}}

  
@article{ConnGoulToin94a,
 author		= {A. R. Conn and N. I. M. Gould and Ph. L. Toint},
 title		= {A note on using alternative second-order models for the
		   subproblems arising in barrier function methods for
		   minimization},
 journal	= NUMMATH,
 volume		= 68, pages = {17--33}, year = 1994}

@article{ConnGoulToin96a,
 author		= {A. R. Conn and N. I. M. Gould and Ph. L. Toint},
 title		= {Numerical experiments with the {{\sf LANCELOT}} package
		   ({R}elease {A}) for large-scale nonlinear optimization},
 journal	= MPA,
 volume		= 73, number = 1, pages = {73--110}, year = 1996,
 abstract	= {In this paper, we describe the algorithmic options of
		   Release A of {\sf LANCELOT}, a Fortran package for
		   large-scale nonlinear optimization. We then present the
		   results of intensive numerical tests and discuss the
		   relative merits of the options. The experiments described
		   involve both academic and applied problems. Finally, we
		   propose conclusions, both specific to {\sf LANCELOT} and of
		   more general scope.},
 summary	= {The algorithmic options available within Release A of {\sf
		   LANCELOT}, a Fortran package for large-scale nonlinear
		   optimization, are presented. The results of intensive
		   numerical tests are described, and the relative merits of
		   the options discussed. The experiments described involve
		   both academic and applied problems. Conclusions specific to
		   {\sf LANCELOT} and of more general scope are made.}}

@inproceedings{ConnGoulToin97,
 author		= {A. R. Conn and N. I. M. Gould and Ph. L. Toint},
 title		= {Methods for Nonlinear Constraints in Optimization
		   Calculations},
 crossref	= {DuffWats97}, pages = {363--390}}
%abstract       = {Ten years ago, the broad consensus among researchers in
%                  constrained optimization was that sequential quadratic
%                  programming (SQP) methods were the methods of choice.
%                  While, in the long term, this position may be justified,
%                  the past ten years have exposed a number of difficulties
%                  with the SQP approach. Moreover, alternative methods have
%                  shown themselves capable of solving large-scale problems.
%                  In this paper, we shall outline the defects with SQP
%                  methods, and discuss the alternatives. In particular, we
%                  shall indicate how our understanding of the subproblems
%                  which inevitably arise in constrained optimization
%                  calculations has improved. We shall also consider the
%                  impact of interior-point methods for inequality
%                  constrained problems, described elsewhere in this volume,
%                  and argue that these methods likely provide a more useful
%                  Newton model for such problems than do traditional SQP
%                  methods. Finally, we shall consider trust-region methods
%                  for constrained problems, and the impact of automatic
%                  differentiation on algorithm design. }

@article{ConnGoulToin97a,
 author		= {A. R. Conn and N. I. M. Gould and Ph. L. Toint},
 title		= {A globally convergent {L}agrangian barrier algorithm for
		   optimization with general inequality constraints and simple
		   bounds},
 journal	= MC,
 volume		= 66, pages = {261--288}, year = 1997}

@article{ConnGoulToin97z,
 author		= {A. R. Conn and N. I. M. Gould and Ph. L. Toint},
 title		= {On the number of inner iterations per outer iteration of a
		   globally convergent algorithm for optimization with general
		   nonlinear inequality constraints and simple bounds},
 journal	= COAP,
 volume		= 7, number = 1, pages = {41--70}, year = 1997}

@inproceedings{ConnGoulToin99,
 author		= {A. R. Conn and N. I. M. Gould and Ph. L. Toint},
 title		= {A Primal-Dual Algorithm for Minimizing a Nonconvex Function 
		   Subject to Bound and Linear Equality Constraints},
 crossref       = {DiPiGian99}, pages = {15--30}}

@article{ConnGoulSartToin93,
 author		= {A. R. Conn and N. I. M. Gould and A. Sartenaer and Ph. L.
		   Toint},
 title		= {Global convergence of a class of trust region algorithms
		   for optimization using inexact projections on convex
		   constraints},
 journal	= SIOPT,
 volume		= 3, number = 1, pages = {164--221}, year = 1993,
 abstract	= {A class of trust region based algorithms is presented for
		   the solution of nonlinear optimization problems with a
		   convex feasible set. At variance with previously published
		   analysis of this type, the theory presented allows for the
		   use of general norms. Furthermore, the proposed algorithms
		   do not require the explicit computation of the projected
		   gradient, and can therefore be adapted to cases where the
		   projection onto the feasible domain may be expensive to
		   calculate. Strong global convergence results are derived
		   for the class. It is also shown that the set of linear and
		   nonlinear constraints that are binding at the solution are
		   identified by the algorithms of the class in a finite
		   number of iterations.},
 summary	= {Trust-region algorithms for the solution
		   of nonlinear optimization problems with a convex feasible
		   set are presented. The theory given allows for the use of
		   general norms. Furthermore, the proposed algorithms do not
		   require the explicit computation of the projected gradient,
		   and can therefore be adapted to cases where the projection
		   onto the feasible domain may be expensive to calculate.
		   Strong global convergence results are derived. The set of
		   linear and nonlinear constraints that are binding at the
		   solution are identified by the algorithms in a finite
		   number of iterations.}}

@article{ConnGoulSartToin96,
 author		= {A. R. Conn and N. I. M. Gould and A. Sartenaer and Ph. L.
		   Toint},
 title		= {Convergence properties of an Augmented {L}agrangian
		   Algorithm for Optimization with a Combination of General
		   Equality and Linear Constraints},
 journal	= SIOPT,
 volume		= 6, number = 3, pages = {674--703}, year = 1996}

@article{ConnGoulSartToin96a,
 author		= {A. R. Conn and N. I. M. Gould and A. Sartenaer and Ph. L.
		   Toint},
 title		= {Convergence properties of minimization algorithms for
		   convex constraints using a structured trust region},
 journal	= SIOPT,
 volume		= 6, number = 4, pages = {1059--1086}, year = 1996,
 abstract	= {In this paper, we present a class of trust region
		   algorithms for minimization problems within convex feasible
		   regions in which the structure of the problem is explicitly
		   used in the definition of the trust region. This
		   development is intended to reflect the possibility that
		   some parts of the problem may be more accurately modelled
		   than others, a common occurrence in large-scale nonlinear
		   applications. After describing the structured trust region
		   mechanism, we prove global convergence for all algorithms
		   in our class.},
 summary	= {A class of structured trust-region algorithms is presented
		   for minimization problems within convex feasible regions,
		   in which the structure of the problem is explicitly used in
		   the definition of the trust region. Global convergence is
		   established.}}

@techreport{ConnGoulOrbaToin99,
 author		= {A. R. Conn and N. I. M. Gould and D. Orban and Ph. L. Toint},
 title		= {A primal-dual trust-region algorithm for minimizing a
		   non-convex function subject to bound and linear equality
		   constraints},
 institution	= FUNDP, address = FUNDP-ADDRESS,
 number		= {TR99-04}, year = 1999,
 abstract	= {A new primal-dual algorithm is proposed for the
		   minimization of non-convex objective functions subject to
		   simple bounds and linear equality constraints. The method
		   uses a primal-dual trust-region model to ensure descent on
		   a suitable merit function. Convergence of a well-defined
		   subsequence of iterates is proved to a second-order
		   critical point from arbitrary starting points. Algorithmic
		   variants are discussed and preliminary numerical results
		   presented.},
 summary	= {A primal-dual algorithm is proposed for the minimization of
		   non-convex objective functions subject to simple bounds and
		   linear equality constraints. The method uses a primal-dual
		   trust-region model to ensure descent on a suitable merit
		   function. Convergence of a well-defined subsequence of
		   iterates is proved to a second-order critical point from
		   arbitrary starting points. Algorithmic variants are
		   discussed and preliminary numerical results presented.}}

@article{ConnLi92,
 author         = {A. R. Conn and Y. Li},
 title          = {A structure-exploiting algorithm for nonlinear minimax
                   problems},
 journal        = SIOPT,
 volume         = 2, number = 2, pages = {242-263}, year = 1992}

@techreport{ConnSinc75,
 author         = {A. R. Conn and J. W. Sinclair},
 title          = {Quadratic programming via a non-differentiable
                      penalty function},
 institution    = {Faculty of Mathematics, University of Waterloo},
 number         = {CORR 75/15}, year = 1975}

@inproceedings{ConnToin96,
 author		= {A. R. Conn and Ph. L. Toint},
 title		= {An algorithm using quadratic interpolation for
		   unconstrained derivative free optimization},
 crossref	= {DiPiGian96}, pages = {27--47},
 abstract	= {This paper explores the use of multivariate interpolation
		   techniques in the context of method for unconstrained
		   optimization that do not require derivatives of the
		   objective function. A new algorithm is proposed that uses
		   quadratic models in a trust region framework. The algorithm
		   is constructed to require few evaluations of the objective
		   function and to be relatively insensitive to noise in the
		   objective function values. Its performance is analyzed on a
		   set of 20 examples, both with and without noise.},
 summary	= {The use of multivariate interpolation techniques is
		   explored in the context of method for unconstrained
		   optimization that do not require derivatives. An algorithm
		   is proposed that uses quadratic models in a trust-region
		   framework. It requires few evaluations of
		   the objective function and is relatively
		   insensitive to noise in the objective function values. Its
		   performance is analyzed on a set of 20 examples, both with
		   and without noise.}}

@article{ConnPiet77,
 author		= {A. R. Conn and T. Pietrzykowski},
 title		= {A penalty function method converging directly to a
		   constrained optimum},
 journal	= SINUM,
 volume		= 14, number = 2, pages = {348--375}, year = 1977}

@inproceedings{ConnScheToin97,
 author		= {A. R. Conn and K. Scheinberg and Ph. L. Toint},
 title		= {On the convergence of derivative-free methods for
		   unconstrained optimization},
 booktitle	= {Approximation Theory and Optimization: Tributes to M. J. D.
		   Powell},
 editor		= {A. Iserles and M. Buhmann},
 publisher	= CUP, address = CUP-ADDRESS,
 pages		= {83--108}, year = 1997,
 abstract	= {The purpose of this paper is to examine a broad class of
		   derivative-free trust-region methods for unconstrained
		   optimization inspired by the proposals of \citebb{Powe94b}
		   and to derive a general framework in which reasonable
		   global convergence results can be obtained. The
		   developments make extensive use of an interpolation error
		   bound derived by \citebb{SaueXu95} in the context of
		   multivariate polynomial interpolation.},
 summary	= {Derivative-free trust-region methods for
		   unconstrained optimization, inspired by \citebb{Powe94b},
		   are discussed and global convergence results obtained. The
		   developments make extensive use of an interpolation error
		   bound derived by \citebb{SaueXu95} in the context of
		   multivariate polynomial interpolation.}}

@article{ConnScheToin97b,
 author		= {A. R. Conn and K. Scheinberg and Ph. L. Toint},
 title		= {Recent progress in unconstrained nonlinear optimization
		   without derivatives},
 journal	= MPB,
 volume		= 79, number = 3, pages = {397--414}, year = 1997,
 abstract	= {We present an introduction to a new class of derivative
		   free methods for unconstrained optimization. We start by
		   discussing the motivation for such methods and why they are
		   in high demand by practitioners. We then review the past
		   developments in this field, before introducing the features
		   that characterize the newer algorithms. In the context of a
		   trust region framework, we focus on techniques that ensure
		   a suitable ``geometric quality'' of the considered models.
		   We then outline the class of algorithms based on these
		   techniques, as well as their respective merits. We finally
		   conclude the paper with a discussion of open questions and
		   perspectives.},
 summary	= {Derivative-free trust-region methods for unconstrained
		   optimization are introduced. Motivation is given, and past
		   developments in the field reviewed.
		   Techniques that ensure a suitable ``geometric quality'' of
		   the models are considered. A discussion of open
		   questions and perspectives is given.}}

@techreport{ConnScheToin98,
 author		= {A. R. Conn and K. Scheinberg and Ph. L. Toint},
 title		= {A Derivative Free Optimization Algorithm in Practice},
 institution	= FUNDP, address = FUNDP-ADDRESS,
 number		= {TR98/11}, year = 1998,
 abstract	= {We consider an algorithm for optimizing, at first without
		   constraints, a nonlinear function whose first-order
		   derivatives exist but are unavailable. The algorithm is
		   based on approximating the objective function by a
		   quadratic polynomial interpolation model and using this
		   model within a trust-region framework. We study some
		   practical properties of the algorithm and show how it can
		   be extended to solve certain constrained optimization
		   problems. We present computational results for analytical
		   and for real-life problems from the aeronautical industry.},
 summary	= {An algorithm is presented for optimizing, at first without
		   constraints, a nonlinear function whose first-order
		   derivatives exist but are unavailable. It is based on
		   approximating the objective function by a quadratic
		   polynomial interpolation model and using this model within
		   a trust-region framework. Some practical properties of the
		   algorithm are studied, including how it can be extended to
		   solve certain constrained optimization problems.
		   Computational results are presented for analytical and for
		   real-life problems from the aeronautical industry.}}

@article{ConnViceVisw99,
 author		= {A. R. Conn and L. N. Vicente and C. Visweswariah},
 title		= {Two-step algorithms for nonlinear optimization with
		   structured applications},
 journal        = SIOPT,
 volume         = 9, number = 4, pages = {924--947}, year = 1999,
 abstract	= {In this paper we propose extensions to trust-region and
		   line-search algorithms in which the classical step is
		   augmented with a second step that is required to yield a
		   decrease in the value of the objective function. The
		   classical convergence theory for trust-region and
		   line-search algorithms is adapted to this class of two-step
		   algorithms. It is shown that the algorithms are globally
		   convergent to a stationary point under the ``classical''
		   assumptions. The algorithms can be applied to any problem
		   with variable(s) whose contribution to the objective
		   function is a known functional form. In the nonlinear
		   programming package {\sf LANCELOT}, they have been applied
		   to update slack variables and variables introduced to solve
		   minimax problems, leading to enhanced optimization
		   efficiency. Numerical results are presented to show the
		   effectiveness of these techniques.},
 summary	= {Extensions to trust-region and line-search algorithms are
		   proposed in which the classical step is augmented with a
		   second step that yields a decrease of the
		   objective function. The convergence theory for
		   trust-region and linesearch algorithms is adapted to this
		   class of two-step algorithms. It is shown that the
		   algorithms are globally convergent. The
		   algorithms can be applied to any problem with variable(s)
		   whose contribution to the objective function is a known
		   functional form. In the nonlinear programming package {\sf
		   LANCELOT}, they have been applied to update slack variables
		   and variables introduced to solve minimax problems, leading
		   to enhanced optimization efficiency. Numerical results are
		   presented.}}

@article{ContTapi93,
 author         = {M. Contreras and R. A. Tapia},
 title          = {Sizing the {BFGS} and {DFP} updates: numerical study},
 journal        = JOTA,
 volume         = 78, number = 1, pages = {93--108}, year = 1993,
 abstract       = {The authors develop and test a strategy for
                   selectively sizing (multiplying by an appropriate
                   scalar) the approximate Hessian matrix before it is
                   updated in the BFGS and DFP trust-region methods for
                   unconstrained optimization. The numerical results
                   imply that, for use with the DFP update, the
                   Oren-Luenberger sizing factor is completely
                   satisfactory and selective sizing is vastly superior
                   to the alternatives of never sizing or
                   first-iteration sizing and is slightly better than
                   the alternative of always sizing. Numerical
                   experimentation showed that the Oren-Luenberger
                   sizing factor is not a satisfactory sizing factor for
                   use with the BFGS update. Therefore, based on the
                   newly acquired understanding of the situation, the
                   authors propose a centered Oren-Luenberger sizing
                   factor to be used with the BFGS update. The numerical
                   experimentation implies that selectively sizing the
                   BFGS update with the centered Oren-Luenberger sizing
                   factor is superior to the alternatives. These results
                   contradict the folk axiom that sizing should be done
                   only at the first iteration. They also show that,
                   without sufficient sizing, DFP is vastly inferior to
                   BFGS and however, when selectively sized, DFP is
                   competitive with BFGS.},
 summary        = {A strategy is developed for selectively sizing the 
		   approximate Hessian matrix before it is
                   updated in the BFGS and DFP trust-region methods for
                   unconstrained optimization. The numerical results
                   suggest that sizing should be done not
                   only at the first iteration. They also show that,
                   without sufficient sizing, DFP is vastly inferior to
                   BFGS and however, when selectively sized, DFP is
                   competitive with BFGS.}}


@article{Cont80,
 author		= {L. B. Contesse},
 title		= {Une caract\'{e}risation compl\`{e}te des minima locaux en
		   programmation quadratique},
 journal	= NUMMATH,
 volume		= 34, pages = {315--332}, year = 1980}

@article{Corr97,
 author		= {G. Corradi},
 title		= {A trust region algorithm for unconstrained optimization},
 journal	= {International Journal of Computer Mathematics},
 volume		= 65, number = {1-2}, pages = {109--119}, year = 1997,
 abstract	= {In this paper a trust region method, based on approximation
		   of $f(\cdot)$ and $f'(\cdot)$ of higher order, is
		   presented. A convergence analysis for the method is
		   considered too. Numerical results are reported.},
 summary	= {A trust region method is proposed which is based on
		   approximation of $f(\cdot)$ and $f'(\cdot)$ of higher
		   order. A convergence analysis for the method is also
		   presented. Numerical results are reported.}}

@inproceedings{CostStanSnym96,
 author		= {J. E. Coster and N. Stander and J. A. Snyman},
 title		= {Trust region augmented {L}agrangian methods with secant
		   {H}essian updating applied to structural optimization},
 booktitle	= {Proceedings of the ASME Design Engineering Technical
		   Conference and Computers in Engineering Conference, August
		   18-22, 1996, Irvine, California},
 year		= 1996,
 abstract	= {The problem of determining the optimal sizing design of
		   truss structures is considered. An augmented Lagrangian
		   optimization algorithm which uses a quadratic penalty term
		   is formulated. The implementation uses a first-order
		   Lagrange multiplier update and a strategy for progressively
		   increasing the accuracy with which the bound constrained
		   minimizations are performed. The allowed constraint
		   violation is also progressively decreased but at a slower
		   rate so as to prevent ill-conditioning due to large penalty
		   values. Individual constraint penalties are used and only
		   the penalties of the worst violated constraints are
		   increased. The scheme is globally convergent. The bound
		   constrained minimizations are performed using the {\em
		   SBMIN} algorithm where a sophisticated trust-region
		   strategy is employed. The Hessian of the augmented
		   Lagrangian function is approximated using partitioned
		   secant updating. Each function contributing to the
		   Lagrangian is individually approximated by a secant update
		   and the augmented Lagrangian Hessian is formed by
		   appropriate accumulation. The performance of the algorithm
		   is evaluated for a number of different secant updates on
		   standard explicit and truss sizing optimization problems.
		   The results show the formulation to be superior to other
		   implementations of augmented Lagrangian methods reported in
		   the literature and that, under certain conditions, the
		   method approaches the performance of the state-of-the-art
		   SQP and SAM methods. Of the secant updates, the symmetric
		   rank one update is superior to the other updates including
		   the BFGS scheme. It is suggested that the individual
		   function, secant updating employed may be usefully applied
		   in contexts where structural analysis and optimization are
		   performed simultaneously, as in the simultaneous analysis
		   and design method. In such cases the functions are
		   partially separable and the associated Hessians are of low
		   rank.},
 summary	= {An augmented Lagrangian algorithm is formulated for the
		   optimal sizing design of
		   truss structures. The scheme is globally convergent. The
		   bound constrained minimizations are performed using the
		   {\sf SBMIN} trust-region algorithm. The Hessian of the
		   augmented Lagrangian is approximated using partitioned
		   secant updating. The performance of the algorithm is
		   evaluated for different secant updates on standard explicit
		   and truss sizing optimization problems. The results show
		   the formulation to be superior to other implementations of
		   augmented Lagrangian methods and that the method may
		   approach the performance of the state-of-the-art SQP and
		   SAM methods. Of the secant updates, the SR1 update is
		   superior to the other updates including the BFGS scheme. 
		   Secant updating may be usefully applied in contexts where
		   structural analysis and optimization are performed
		   simultaneously, as in the simultaneous analysis and design
		   method. In such cases the functions are partially
		   separable.}}

@book{CottPangSton92,
 author  	= {R. W. Cottle and J.-S. Pang and R. E. Stone},
 title   	= {The Linear Complementarity Problem},
 publisher 	= AP, address = AP-ADDRESS,
 year    	= 1992}

@article{Cour43,
 author		= {R. Courant},
 title		= {Variational methods for the solution of problems of
		   equilibrium and vibrations},
 journal	= {Bulletin of the American Mathematical Society},
 volume		= 49, pages = {1--23}, year = 1943}

@manual{CPLEX98,
 author      	= {{CPLEX 6.0}},
 title       	= {High-performance linear, integer and quadratic programming 
                   software},
 organization	= {ILOG SA}, address = {Gentilly, France},
 year        	= 1998}

@book{Crye82,
 author		= {C. W. Cryer},
 title		= {Numerical Functional Analysis},
 publisher	= OUP, address = OUP-ADDRESS,
 year		= 1982}

@article{CullWill80,
 author		= {J. Cullum and R. A. Willoughby},
 title		= {The {L}anczos phenomenon---an interpretation based upon
		   conjugate gradient optimization},
 journal	= LAA,
 volume		= 29, pages = {63--90}, year = 1980}
% abstract       = {The equivalence in exact arithmetic of the Lanczos 
%                  tridiagonalization procedure and the conjugate gradient 
%                  optimization procedure for solving Ax=b, where A is a real 
%                  symmetric, positive definite matrix, is well known.  
%                  We demonstrate that a relaxed equivalence is valid in the 
%                  presence of errors.  Specifically we demonstrate that local 
%                  $\epsilon$-orthonormality of the Lanczos vectors guarantees 
%                  local $\epsilon$-A-conjugacy of the direction vectors in the 
%                  associated conjugate gradient procedure. Moreover we 
%                  demonstrate that all the conjugate gradient relationships 
%                  are satisfied approximately. Therefore, any statements valid 
%                  for the conjugate gradient optimization procedure, which we 
%                  show converges under very weak conditions, apply directly to 
%                  the Lanczos procedures.  We then use this equivalence to 
%                  obtain an explanation of the Lanczos phenomenon:  the 
%                  empirically observed "convergence" of Lanczos eigenvalue 
%                  procedures despite total loss of the global orthogonality of 
%                  the Lanczos vectors.},
% summary        = {It is demonstrated that there is a one sided 
%                  $\epsilon$-equivalence relationship between the practical
%		  Lanczos tridiagonalizarion procedure and the conjugate
%		  gradient optimization procedure for solving Ax=b.  This
%		  equivalence allows the exploitation of properties of the
%		  optimization procedure to provide a plausible mechanism for
%		  explaining the observed Lanczos phenomenon.  The arguments
%		  required an assumption on the variation in the ratios of the
%		  norms of the residuals that seems to occur in practice,
%		  although no proof that it occurs in general was presented.
%		  This equivalence was also used to provide, for positive
%		  definite matrices, a convergence argument for the SYMMLQ
%		  Lanczos procedure for solving systems of equations developed
%		  in \citebb{PaigSaun75} and for the related procedure for
%		  computing elements of A-1 used in \citebb{KaplGray76}}

@article{CurtPoweReid74,
 author		= {A. R. Curtis and M. J. D. Powell and J. K. Reid},
 title		= {On The Estimation of Sparse {J}acobian Matrices},
 journal	= JIMA,
 volume		= 13, pages = {117--119}, year = 1974}

%%% D %%%

@article{Dafe80,
 author		= {S. Dafermos},
 title		= {Traffic equilibrium and variational inequalities},
 journal	= {Transportation Science},
 volume		= 14, pages = {42--54}, year = 1980}

@article{Dani67a,
 author		= {J. W. Daniel},
 title		= {The conjugate gradient method for linear and nonlinear
		   operator equations},
 journal	= SINUM,
 volume		= 4, pages = {10--25}, year = 1967}

@article{Dani67b,
 author		= {J. W. Daniel},
 title		= {Convergence of the conjugate gradient method with
		   computationally convenient modifications},
 journal	= NUMMATH,
 volume		= 10, pages = {125--131}, year = 1967}

@book{Dant63,
 author  	= {G. B. Dantzig},
 title   	= {Linear Programming and Extensions},
 publisher 	= {Princeton Uiversity Press}, address = {Princeton, USA},
 year    	= 1963}

@techreport{Das96,
 author		= {I. Das},
 title		= {An interior point algorithm for the general nonlinear
		   programming problem with trust region globalization},
 institution	= ICASE, address = ICASE-ADDRESS,
 number		= {96--61}, year = 1996,
 abstract	= {This paper presents an SQP-based interior point technique
		   for solving the general nonlinear programming problem using
		   trust region globalization and the \citebb{ColeLi96b}
		   scaling. The SQP subproblem is decomposed into a normal and
		   a reduced tangential subproblem in the tradition of
		   numerous works on equality constrained optimization, and
		   strict feasibility is maintained with respect to the
		   bounds. This is intended to be an extension of previous
		   work by \citebb{ColeLi96b} and \citebb{Vice96}. Though no
		   theoretical proofs of convergence are provided, some
		   computational results are presented which indicate that
		   this algorithm holds promise. The computational experiments
		   have been geared towards improving the semi-local
		   convergence of the algorithm; in particular high
		   sensitivity of the speed of convergence with respect to the
		   fraction of the trust region radius allowed for the normal
		   step and with respect to the initial trust region radius
		   are observed. The chief advantages of this algorithm over
		   primal-dual interior point algorithms are better handling
		   of the `sticking problem' and a reduction in the number of
		   variables by elimination of the multipliers of bound
		   constraints.},
 summary	= {An SQP-based interior-point technique is presented for
		   solving the general nonlinear programming problem using
		   trust-region globalization and the \citebb{ColeLi96b}
		   scaling. The SQP subproblem is decomposed into a normal
		   and a reduced tangential subproblem, and strict feasibility
		   is maintained with respect to the bounds. Computational
		   experiments have been geared towards improving the
		   semi-local convergence of the algorithm; in particular high
		   sensitivity of the speed of convergence with respect to the
		   fraction of the trust region radius allowed for the normal
		   step and with respect to the initial trust region radius
		   are observed. The chief advantages of this algorithm over
		   primal-dual interior-point algorithms are better handling
		   of the `sticking problem' and a reduction in the number of
		   variables by elimination of the multipliers of bound
		   constraints.}}

@article{Davi68,
 author		= {W. C. Davidon},
 title		= {Variance algorithms for minimization},
 journal	= COMPJ,
 volume		= 10, pages = {406--410}, year = 1968}

@article{Davi75,
 author		= {W. C. Davidon},
 title		= {Optimally Conditioned Optimization Algorithms Without Line
		   Searches},
 journal	= MP,
 volume		= 9, number = 1, pages = {1--30}, year = 1975}

@article{Dean92,
 author		= {E. J. Dean},
 title		= {A Model Trust-Region Modification of {N}ewton Method for
		   Nonlinear 2-Point Boundary-Value-Problems},
 journal	= {Journal of Optimization Theory and Applications},
 volume		= 75, number = 2, pages = {297--312}, year = 1992,
 abstract	= {The method of quasilinearization for nonlinear two-point
		   boundary-value problems is Newton's method for a nonlinear
		   differential operator equation. A model trust-region
		   approach to globalizing the quasilinearization algorithm is
		   presented. A double-dogleg implementation yields a globally
		   convergent algorithm that is robust in solving difficult
		   problems.},
 summary	= {The method of quasilinearization for nonlinear two-point
		   boundary- value problems is Newton's method for a nonlinear
		   differential operator equation. A model trust-region
		   approach to globalizing the quasilinearization algorithm is
		   presented. A double-dogleg implementation yields a globally
		   convergent algorithm that is robust in solving difficult
		   problems.}}

@article{DeBoRon92,
 author		= {De Boor, C. and A. Ron},
 title		= {Computational aspects of polynomial interpolation in
		   several variables},
 journal	= MC,
 volume		= 58, number = 198, pages = {705--727}, year = 1992}

@techreport{DeLuFaccKanz95,
 author		= {De Luca, T. and F. Facchinei and Ch. Kanzow},
 title		= {A semismooth approach to the solution of nonlinear
		   complementarity problems},
 institution	= HAMBURG, address = HAMBURG-ADDRESS,
 number		= 93, year = 1995}

@article{DembEiseStei82,
 author		= {R. S. Dembo and S. C. Eisenstat and T. Steihaug},
 title		= {Inexact-{N}ewton Methods},
 journal	= SINUM,
 volume		= 19, number = 2, pages = {400--408}, year = 1982}

@article{DembStei83,
 author		= {R. S. Dembo and T. Steihaug},
 title		= {Truncated-{N}ewton Algorithms for Large-Scale Unconstrained
		   Optimization},
 journal	= MP,
 volume		= 26, pages = {190--212}, year = 1983}

@techreport{DembTulo83,
 author		= {R. S. Dembo and U. Tulowitzki},
 title		= {On the minimization of quadratic functions subject to box
		   constraints},
 institution	= {Yale University}, address = {Yale, USA},
 type		= {School of Organization and Management Working paper },
 number		= {Series B no. 71}, year = 1983}

@book{DemyMalo74,
 author         = {V. F. Dem'yanov and V. N. Malozemov},
 title          = {Introduction to Minmax},
 publisher      = WILEY, address = WILEY-ADDRESS,
 year           = 1974}

@article{DengXiaoZhou93,
 author		= {N. Deng and Y. Xiao and F. Zhou},
 title		= {Nonmonotonic Trust Region Algorithms},
 journal	= JOTA,
 volume		= 76, number = 2, pages = {259--285}, year = 1993,
 abstract	= {A non-monotonic trust region method for unconstrained
		   optimization problems is presented. Although the method
		   allows the sequence of values of the objective function to
		   be non-monotonic, convergence properties similar to those
		   for the usual trust region method are proved under certain
		   conditions, including conditions on the approximate
		   solutions to the subproblem. To make the solution satisfy
		   these conditions, an algorithm to solve the subproblem is
		   also established. Finally, some numerical results are
		   reported which show that the non-monotonic trust region
		   method is superior to the usual trust region method
		   according to both the number of gradient evaluations and
		   the number of function evaluations.},
 summary	= {A non-monotonic trust-region method for unconstrained
		   optimization is presented, whose convergence
		   properties are similar to those for the usual trust-region
		   method under conditions including requirements
		   on the approximate solutions to the subproblem. An
		   algorithm to solve the subproblem is also presented and
		   numerical results discussed.}}

@inproceedings{Denn78,
 author		= {J. E. Dennis},
 title		= {A brief introduction to quasi-{N}ewton methods},
 booktitle	= {Numerical Analysis},
 editor		= {G. H. Golub and J. Oliger},
 publisher	= AMS, address = AMS-ADDRESS,
 series		= {Proceedings of Symposia in Applied Mathematics},
 number		= 22, pages = {19--52}, year = 1978}

@article{DennElAlMaci97,
 author		= {J. E. Dennis and M. El{-}Alem and M. C. Maciel},
 title		= {A global convergence theory for general Trust-Region based
		   algorithms for equality constrained optimization},
 journal	= SIOPT,
 volume		= 7, number = 1, pages = {177--207}, year = 1997,
 abstract	= {A class of algorithms based on the successive quadratic
		   programming method for solving the general nonlinear
		   programming problem is presented. The objective function
		   and the constraints of the problem are only required to be
		   differentiable and their gradients to satisfy a Lipschitz
		   condition. The strategy for obtaining global convergence is
		   based on the trust-region approach. The merit function is
		   an augmented Lagrangian. A new updating technique is
		   introduced for the penalty parameter, by means of which
		   monotone increase is not necessary. Global convergence
		   results are proved and numerical experiments are presented.},
 summary	= {A class of algorithms based on the SQP method for general
		   nonlinear programming is presented. The objective function
		   and the constraints of the problem are only required to be
		   differentiable and their gradients to satisfy a Lipschitz
		   condition. Global convergence is obtained by using a
		   trust-region approach. The merit function is an augmented
		   Lagrangian. A possibly non-monotone updating technique is
		   introduced for the penalty parameter. Global convergence
		   results are proved and numerical experiments presented.}}

@article{DennElAlWill99,
 author		= {J. E. Dennis and M. El{-}Alem and K. A. Williamson},
 title		= {A trust-region approach to nonlinear systems of equalities
		   and inequalities},
 journal        = SIOPT,
 volume 	= 9, number = 2, pages = {291--315}, year = 1999,
 abstract	= {In this paper, two new trust-region algorithms for the
		   numerical solution of systems of nonlinear equalities and
		   inequalities are introduced. The formulation is free of
		   arbitrary parameters and possesses sufficient smoothness to
		   exploit the robustness of the trust-region approach. The
		   proposed algorithms are one-sided least-squares
		   trust-region algorithms. The first algorithm is a single
		   model algorithm, and the second one is a multi-model
		   algorithm where the Cauchy point computation is a model
		   selection procedure. Global convergence analysis for the
		   two algorithms are presented. Our analysis generalizes to
		   nonlinear systems of equalities and inequalities the
		   well-developed theory for nonlinear least-squares problems.
		   Numerical experiments on the two algorithms are also
		   presented. The performance of the two algorithm are
		   reported. The numerical results validate the effectiveness
		   of our approach.},
 summary	= {Two one-sided trust-region algorithms for the numerical
		   solution of systems of nonlinear equalities and
		   inequalities are introduced. The first is a single model
		   algorithm, while the second uses multiple models with
		   the Cauchy point computation being used a model selection
		   procedure. Global convergence analysis is presented for
		   both algorithms, and numerical experiments show their
		   effectiveness.}}

@article{DennEcheGuarMartScolVacc91,
 author         = {J. E. Dennis and N. Echebest and M. T. Guardarucci and 
                   J. M. Mart\'{\i}nez and H. D. Scolnik and C. Vacchino},
 title          = {A Curvilinear Search using Tridiagonal Secant Updates for 
                   Unconstrained Optimization},
 journal        = SIOPT,
 volume         = 1, number = 3, pages = {333--357}, year = 1991}

@article{DennGayWels81,
 author		= {J. E. Dennis and D. M. Gay and R. E. Welsh},
 title		= {An adaptive nonlinear least squares algorithm},
 journal	= TOMS,
 volume		= 7, number = 3, pages = {348--368}, year = 1981}
 abstract       = {NL2SOL is a modular program for solving nonlinear
                   least-squares problems that incorporates a number of
                   novel features. It maintains a secant approximation S
                   to the second-order part of the least-squares Hessian
                   and adaptively decides when to use this
                   approximation. S is 'sized' before updating,
                   something that is similar to Oren-Luenberger
                   scaling. The step choice algorithm is based on
                   minimizing a local quadratic model of the sum of
                   squares function constrained to an elliptical trust
                   region centered at the current approximate
                   minimizer. This is accomplished using ideas discussed
                   by More (1978) together with a special module for
                   assessing the quality of the step thus
                   computed. These and other ideas behind NL2SOL are
                   discussed, and its evolution and current
                   implementation are also described briefly.},
 summary        = {NL2SOL is a modular program for solving nonlinear
                   least-squares problems. It maintains a sized 
		   secant approximation to the second-order part of
		   the least-squares Hessian and adaptively decides when
		   to use this approximation. The step choice algorithm
		   is based on minimizing a local quadratic model of the
		   sum of squares function constrained to an elliptical trust
                   region.}}


@article{DennHeinVice98,
 author		= {J. E. Dennis and M. Heinkenschloss and L. N. Vicente},
 title		= {Trust-region interior-point {SQP} algorithms for a class of
		   nonlinear programming problems},
 journal	= SICON,
 volume		= 36, number = 5, pages = {1750--1794}, year = 1998,
 abstract	= {In this paper, a family of trust-region interior-point
		   sequential quadratic programming (SQP) algorithms for the
		   solution of a class of minimization problems with nonlinear
		   equality constraints and simple bounds on some of the
		   variables is described and analyzed. Such nonlinear
		   programs arise, e.g., from the discretization of optimal
		   control problems. The algorithms treat states and controls
		   as independent variables. They are designed to take
		   advantage of the structure of the problem. In particular
		   they do not rely on matrix factorizations of the linearized
		   constraints but use solutions of the linearized state
		   equation and the adjoint equation. They are well suited for
		   large scale problems arising from optimal control problems
		   governed by partial differential equations. The algorithms
		   keep strict feasibility with respect to the bound
		   constraints by using an affine scaling method proposed, for
		   a different class of problems, by \citebb{ColeLi96b} and
		   they exploit trust-region techniques for
		   equality-constrained optimization. Thus, they allow the
		   computation of the steps using a variety of methods,
		   including many iterative techniques. Global convergence of
		   these algorithms to a first-order Karush- Kuhn-Tucker (KKT)
		   limit point is proved under very mild conditions on the
		   trial steps. Under reasonable, but more stringent,
		   conditions on the quadratic model and on the trial steps,
		   the sequence of iterates generated by the algorithms is
		   shown to have a limit point satisfying the second-order
		   necessary KKT conditions. The local rate of convergence to
		   a nondegenerate strict local minimizer is q-quadratic. The
		   results given here include, as special cases, current
		   results for only equality constraints and for only simple
		   bounds. Numerical results for the solution of an optimal
		   control problem governed by a nonlinear heat equation are
		   reported.},
 summary	= {Trust-region interior-point  SQP algorithms are presented
		   for solving minimization problems with nonlinear equality
		   constraints and simple bounds. The algorithms treat states
		   and controls as independent variables and take advantage of
		   the structure of the problem. In particular they do not rely
		   on matrix factorizations of the linearized constraints but
		   use solutions of the linearized state equation and the
		   adjoint equation. They are suited for large-scale problems
		   arising from optimal control problems governed by partial
		   differential equations. They keep strict feasibility with
		   respect to the bound constraints by using an affine-scaling
		   method inspired by \citebb{ColeLi96b} and they exploit
		   trust-region techniques for equality-constrained
		   optimization. They allow the computation of the steps using
		   a variety of methods, including many iterative techniques.
		   Global convergence is proved under very mild conditions on
		   the trial steps. Under more stringent
		   conditions on the quadratic model and on the trial steps,
		   the iterates converge Q-quadratically to a 
		   limit point satisfying the second-order necessary
		   conditions. Numerical results are reported for an optimal
		   control problem governed by a nonlinear heat equation.}}

@article{DennLiTapi95,
 author		= {J. E. Dennis and S. B. B. Li and R. A. Tapia},
 title		= {A unified approach to global convergence of trust region
		   methods for nonsmooth optimization},
 journal	= MP,
 volume		= 68, number = 3, pages = {319--346}, year = 1995,
 abstract	= {This paper investigates the global convergence of
		   trust-region (TR) mthods for solving nonsmooth minimization
		   problems. For a class of nonsmooth objective functions
		   called regular functions, conditions are found on the TR
		   local models that imply three fundamental convergence
		   properties. These conditions are shown to be satisfied by
		   appropriate forms of \citebb{Flet87}'s TR method for
		   solving constrained optimization problems, \citebb{Powe83}
		   and \citebb{Yuan83}'s TR method for solving nonlinear
		   fitting problems, \citebb{DuffNoceReid87}'s TR method for
		   solving systems of nonlinear equations, and
		   \citebb{ElHaTapi93}'s TR method for solving systems of
		   nonlinear equations. Thus our results can be viewed as a
		   unified convergence theory for TR methods for nonsmooth
		   problems.},
 summary	= {The global convergence of trust-region methods for
		   non-smooth minimization is investigated. Conditions are
		   found on the local models that imply three convergence
		   properties for regular problems. These conditions are
		   satisfied by appropriate forms of \citebb{Flet87}'s method
		   for constrained optimization, \citebb{Powe83} and
		   \citebb{Yuan83}'s method for solving nonlinear fitting
		   problems, and \citebb{DuffNoceReid87}'s and
		   \citebb{ElHaTapi93}'s methods for solving systems of
		   nonlinear equations. The results may thus be viewed as a
		   unified convergence theory for trust-region methods for
		   non-smooth problems.}}
 
@article{DennMei79,
 author		= {J. E. Dennis and H. H. W. Mei},
 title		= {Two New Unconstrained Optimization Algorithms Which Use
		   Function and Gradient Values},
 journal	= JOTA,
 volume		= 28, number = 4, pages = {453--482}, year = 1979,
 abstract	= {Two new methods for unconstrained optimization are
		   presented. Both methods employ a hybrid direction strategy
		   which is a modification of \citebb{Powe70c}'s dogleg
		   strategy. They also employ a projection technique
		   introduced by \citebb{Davi75} which uses projection images
		   of $\Delta x$ and $\Delta g$ in updating the approximate
		   Hessian. The first method uses Davidon's optimally
		   conditioned update formula, while the second uses only the
		   BFGS update. Both methods performed well without Powell's
		   special iterations and singularity safeguards, and the
		   numerical results are very promising.},
 summary	= {Two methods for unconstrained optimization are presented.
		   They employ a hybrid direction strategy, which is a
		   modification of \citebb{Powe70c}'s dogleg strategy, and a
		   projection technique introduced by \citebb{Davi75} which
		   uses projection images of $\Delta x$ and $\Delta g$ in
		   updating the approximate Hessian. The first method uses
		   Davidon's optimally conditioned update formula, while the
		   second uses only the BFGS update. Both methods performed
		   well without Powell's special iterations and singularity
		   safeguards.}}

@book{DennSchn83,
 author		= {J. E. Dennis and R. B. Schnabel},
 title		= {Numerical Methods for Unconstrained Optimization and
		   Nonlinear Equations},
 publisher	= PH, address = PH-ADDRESS,
 year		= 1983,
 note           = {Reprinted as \emph{Classics in Applied Mathematics 16}, SIAM,
		   Philadelphia, USA, 1996}}

@article{DennTorc91,
 author		= {J. E. Dennis and V. Torczon},
 title		= {Direct Search Methods on Parallel Machines},
 journal	= SIOPT,
 volume		= 1, number = 4, pages = {448--474}, year = 1991}

@inproceedings{DennTorc97,
 author		= {J. E. Dennis and V. Torczon},
 title		= {Managing Approximation Models in Optimization},
 booktitle	= {Multidisciplinary Design Optimization},
 editor		= {N. M. Alexandrov and M. Y. Hussaini},
 publisher	= SIAM, address = SIAM-ADDRESS,
 pages		= {330--347}, year = 1997,
 abstract	= {It is standard engineering practice to use approximation
		   models in place of expensive simulations to drive an
		   optimal design process based on nonlinear programming
		   algorithms. This paper uses well-established notions from
		   the literature on trust-region methods and a powerful
		   global convergence theory for pattern search methods to
		   manage the interplay between optimization and the fidelity
		   of the approximation models to insure that the process
		   converges to a reasonable solution of the original design
		   problem. We present a specific example from the class of
		   algorithms outlined here, but many other interesting
		   options exist that we will explore in later work. The
		   algorithm we present as an example of the management
		   strategies we propose is based on a family of pattern
		   search algorithms developed by the authors. Pattern search
		   methods can be successfully applied when only ranking
		   (ordinal) information is available and when derivatives are
		   either unavailable or unreliable. Since we are interested
		   here in using approximations to provide arguments for the
		   objective function, our choice seems relevant. This work is
		   in support of the Rice effort in collaboration with Boeing
		   and IBM to look at the problem of designing helicopter
		   rotor blades.},
 summary	= {It is standard engineering practice to use approximation
		   models in place of expensive simulations to drive an
		   optimal design process based on nonlinear programming
		   algorithms. Known notions on trust-region methods and a
		   global convergence theory for pattern search methods are
		   used to manage the interplay between optimization and the
		   fidelity of the approximation models to insure that the
		   process converges to a reasonable solution of the original
		   problem. The algorithm given as an example is based on the
		   family of pattern search algorithms by \citebb{DennTorc91},
		   which can be successfully applied when only ranking (ordinal)
		   information is available and when derivatives are either
		   unavailable or unreliable.}}

@inproceedings{DennVice96,
 author		= {J. E. Dennis and L. N. Vicente},
 title		= {Trust Region Interior-Point Algorithms for minimization
		   problems with simple bounds},
 booktitle      = {Applied Mathematics and Parallel Computing, 
                   Festschrift for  Klaus Ritter},
 editor         = {H. Fisher and B. Riedm\u{u}ller and S. Sch\u{a}ffler},
 publisher      = {Physica-Verlag, Springer-Verlag},
 address        = SPRINGER-ADDRESS,
 pages          = {97--107}, year = 1996,
 abstract	= {Two trust-region interior-point algorithms for the solution
		   of minimization problems with simple bounds are presented.
		   The algorithms scale the local model in a way proposed by
		   \citebb{ColeLi96b}, but they are new otherwise. The first
		   algorithm is more usual in that the trust region and the
		   local quadratic model are consistently scaled. The second
		   algorithm proposed here uses an unscaled trust region. A
		   first-order convergence result for these algorithms is
		   given and dogleg and conjugate-gradient algorithms to
		   compute trial steps are introduced. Some numerical examples
		   that show the advantages of the second algorithm are
		   presented.},
 summary	= {Two trust-region interior-point algorithms for the solution
		   of minimization problems with simple bounds are presented,
		   that scale the local model as proposed by
		   \citebb{ColeLi96b}. In the first, the
		   trust region and the local quadratic model are consistently
		   scaled. The second uses an unscaled trust region. A
		   first-order convergence result is
		   given and dogleg and conjugate-gradient algorithms to
		   compute trial steps introduced. Numerical examples
		   illustrate the advantages of the second algorithm.}}
%also 
%institution = CAAM, address = RICE-ADDRESS,
%number         = {TR94-42}, year = 1994,

@article{DennVice97,
 author		= {J. E. Dennis and L. N. Vicente},
 title		= {On the Convergence Theory of Trust-Region Based Algorithms
		   for Equality-Constrained Optimization},
 journal	= SIOPT,
 volume		= 7, number = 4, pages = {927--950}, year = 1997,
 abstract	= {In a recent paper, \citebb{DennElAlMaci97} developed a
		   global first-order convergence theory for a general
		   trust-region-based algorithm for equality-constrained
		   optimization. This general algorithm is based on
		   appropriate choices of trust-region subproblems and seems
		   particularly suitable for large problems. This paper
		   presents the global second-order convergence theory for the
		   same general trust-region-based algorithm. The results
		   given here can be seen as a generalization of the
		   second-order convergence results for trust-region methods
		   for unconstrained optimization obtained by
		   \citebb{MoreSore83}. The behavior of the trust region
		   radius and the local rate of convergence are analyzed. Some
		   interesting facts concerning the trust-region subproblem
		   for the linearized constraints, the quasi-normal component
		   of the step and the hard case are presented. It is shown
		   how these results can be applied to a class of discretized
		   optimal control problems.},
 summary	= {A global second-order convergence theory is given
		   for the algorithm of \citebb{DennElAlMaci97}, that
		   generalizes second-order
		   convergence results of \citebb{MoreSore83}. The behaviour
		   of the trust-region radius and the local rate of
		   convergence are analyzed. Some results concerning
		   the trust-region subproblem for the linearized constraints,
		   the quasi-normal component of the step and the hard case
		   are presented. It is shown how these results can be applied
		   to some discretized optimal control problems.}}
%also 
%institution = CAAM, address = RICE-ADDRESS,
%number         = {TR94-36}, year = 1994,

@inproceedings{DennWill88,
 author         = {J. E. Dennis and K. A. Williamson},
 title          = {A new parallel optimization algorithm for parameter 
                   identification in ordinary differential equations},
 booktitle      = {Proceedings of the 27th IEEE Conference on Decision and 
                   Control},
 publisher      = {IEEE}, address = {New York, NY, USA}, 
 volume         = 3, pages = {1836--1840}, year = 1988,
 abstract       = {Standard approaches to the solution of the parameter
                   identification problem in systems of ordinary
                   differential equations are reviewed. An algorithm
                   that is based on the \citebb{CeliDennTapi85}
                   trust region algorithm for
                   equality-constrained optimization problems is
                   described. This algorithm should be both more
                   efficient and more stable than standard solution
                   techniques, and it also provides a flexible framework
                   for introducing parallelism into the parameter
                   identification problem.},
 summary        = {A variant of the \citebb{CeliDennTapi85} trust-region
		   algorithm for equality-constrained optimization problems is
                   described in the context of parameter identification
		   in  ordinary differential equations}}

@article{deSaYuanSun97,
 author		= {de Sampaio, R. J. B. and J. Yuan and W. Sun},
 title		= {Trust region algorithm for nonsmooth optimization},
 journal	= {Applied Mathematics and Computation},
 volume		= 85, number = {2-3}, pages = {109--116}, year = 1997,
 abstract	= {Minimization of a composite function $h(f(x))$ is
		   considered here, where $f: \Re^n \leftarrow \Re^m$ is a
		   locally Lipschitzian function, and $h: \Re^m \leftarrow
		   \Re$ is a continuously differentiable convex function.
		   Theory of trust region algorithm for nonsmooth optimization
		   given by \citebb{Flet87}, and \citebb{PoweYuan90} is
		   extended to this case. Trust region algorithm and its
		   global convergence are studied. Finally, some applications
		   on nonlinear and nonsmooth least squares problems are also
		   given.},
 summary	= {Minimization of a composite function $h(f(x))$ is
		   considered, where $f:\Re^n \leftarrow \Re^m$ is a locally
		   Lipschitzian function, and $h: \Re^m \leftarrow \Re$ is a
		   continuously differentiable convex function. The theory of
		   trust region algorithms for non-smooth optimization given
		   by \citebb{Flet87}, and \citebb{PoweYuan90} is extended to
		   this case. A trust-region algorithm and its global
		   convergence are studied. Some applications to nonlinear and
		   non-smooth least-squares problems are given.}}

@inproceedings{DeScDeMo97,
 author		= {De Schutter, B. and De Moor, B.},
 title		= {The Extended Linear Complementarity Problem and Its
		   Applications in the Max-Plus Algebra},
 crossref	= {FerrPang97}, pages = {22--39}}

@article{DeufPotr92,
 author		= {P. Deuflhard and F. A. Potra},
 title		= {Asymptotic Mesh Independence for {N}ewton--{G}alerkin
		   Methods via a Refined {M}ysovskii Theorem},
 journal	= SINUM,
 volume		= 29, number = 5, pages = {1395--1412}, year = 1992}

@article{DiSun96,
 author		= {S. Di and W. Sun},
 title		= {A trust region method for conic model to solve
		   unconstrained optimization},
 journal	= OMS,
 volume		= 6, number = 4, pages = {237--263}, year = 1996,
 abstract	= {A trust region method for conic models to solve
		   unconstrained optimization problems is proposed. We analyze
		   the trust region approach for conic models and present
		   necessary and sufficient conditions for the solution of the
		   associated trust region subproblems. A corresponding
		   numerical algorithm is developed and has been tested for 19
		   standard test functions in unconstrained optimization. The
		   numerical results show that this method is superior to some
		   advanced methods in the current software libraries.
		   Finally, we prove that the proposed method has global
		   convergence and Q-superlinear convergence properties.},
 summary	= {A trust-region method using conic models is proposed for
		   solving unconstrained optimization problems. Necessary and
		   sufficient conditions for the solution of the associated
		   subproblems are given. The method is globally
		   and Q-superlinearly convergent. Numerical experiments are
		   reported.}}

@techreport{DiniGomeSant98,
 author		= {M. A. Diniz{-}Ehrhardt and M. A. Gomes{-}Ruggiero and S. A.
		   Santos},
 title		= {Numerical analysis of leaving-face parameters in
		   bound-constrained quadratic minimization},
 institution	= UNICAMP, address = UNICAMP-ADDRESS,
 number		= {52/98}, year = 1998,
 abstract	= {In this work, we focus our attention on the quadratic
		   subproblem of trust-region algorithms for large-scale
		   bound-constrained minimization. An approach that combines a
		   mild active set strategy with gradient projection
		   techniques is employed in the solution of large-scale
		   bound-constrained quadratic problems. To fill in some gaps
		   that have appeared in previous work, we propose, test and
		   analyze heuristics which dynamically choose the parameters
		   in charge of the decision of leaving or not the current
		   face of the feasible set. The numerical analysis is based
		   on problems from CUTE collection and randomly generated
		   convex problems with controlled conditioning and
		   degeneracy. The practical consequences of an appropriate
		   decision of such parameters are shown to be crucial,
		   particularly when dual degenerate and ill-conditioned
		   problems are solved.},
 summary	= {The problem of leaving the current face of the feasible
		   domain in a combined active-set and gradient-projection
		   method for large-scale bound-constrained quadratic problems
		   is considered. Heuristics which dynamically choose the
		   parameters in charge of the decision are proposed, tested
		   and analyzed. The practical consequences of an appropriate
		   choice of such parameters are crucial for
		   dual-degenerate and ill-conditioned problems.}}

@article{DiniGomeSant98b,
 author		= {M. A. Diniz{-}Ehrhardt and M. A. Gomes{-}Ruggiero and S. A.
		   Santos},
 title		= {Comparing the numerical performance of two trust-region
		   algorithms for large-scale bound-constrained minimization},
 journal	= {Investigaci\'{o}n Operativa},
 note		= {To appear.}, year = 1998,
 abstract	= {In this work we compare the numerical performance of the
		   software BOX-QUACAN with the package LANCELOT. We put
		   BOX-QUACAN in a context by means of solving an extensive
		   set of problems, so that specific features of both
		   approaches are compared. Through the computational tests,
		   conclusions are made about the classes of problems for
		   which each algorithm suits better and ideas for future
		   research are devised.},
 summary	= {The numerical performance of the BOX-QUACAN and {\sf
		   LANCELOT} software packages are compared on an extensive set 
		   of problems. Conclusions are drawn about the classes of
		   problems for which each package performs better.}}

@article{DiPiFaccGrip92,
 author		= {Di Pillo, G. and F. Facchinei and L. Grippo},
 title		= {An {RQP} algorithm using a differentiable exact penalty
		   function for inequality constrained problems},
 journal	= MP,
 volume		= 55, number = 1, pages = {49--68}, year = 1992}

@article{DipiGrip85,
 author		= {Di Pillo, G. and L. Grippo},
 title		= {A continuously differentiable exact penalty-function method
		   for nonlinear programming with inequality constraints},
 journal	= SICON,
 volume		= 23, number = 1, pages = {72--84}, year = 1985}
 
@article{DipiGrip86,
 author		= {Di Pillo, G. and L. Grippo},
 title		= {An exact penalty-function method with global convergence
		   properties for nonlinear programming problems},
 journal	= MP,
 volume		= 36, number = 1, pages = {1--18}, year = 1986}

@article{Diki67,
 author		= {I. I. Dikin},
 title		= {Iterative solution of problems of linear and quadratic
		   programming},
 journal	= {Doklady Akademiia Nauk USSR},
 volume		= 174, pages = {747--748}, year = 1967}

@book{DikiZork80,
 author		= {I. I. Dikin and V. I. Zorkaltsev},
 title		= {Iterative Solutions of Mathematical Programming Problems},
 publisher	= {Nauka}, address = {Novosibirsk},
 year		= 1980}

@article{DirkFerr95,
 author		= {S. P. Dirkse and M. C. Ferris},
 title		= {The {PATH} Solver: a Non-Monotone Stabilization Scheme
		   for Mixed Complementarity Problems},
 journal	= OMS,
 volume		= 5, number = 2, pages = {123--156}, year = 1995}
 
@phdthesis{Djan79,
 author  	= {A. Djang},
 title   	= {Algorithmic equivalence in quadratic programming},
 school 	= STANFORD, address = STANFORD-ADDRESS,
 year    	= 1979}

@book{DongBuncMoleStew79,
 author		= {J. J. Dongarra and J. R. Bunch and C. B. Moler and G. W.
		   Stewart},
 title		= {{LINPACK} Users's guide},
 publisher	= SIAM, address = SIAM-ADDRESS,
 year		= 1979}

@book{DongDuffSoreVors98,
 author		= {J. J. Dongarra and I. S. Duff and D. C. Sorensen and van
		   der Vorst, H. A.},
 title		= {Numerical Linear Algebra for High-Performance Computers},
 publisher	= SIAM, address = SIAM-ADDRESS,
 year		= 1998}

@article{Dost97,
 author		= {Z. Dost\'{a}l},
 title		= {Box Constrained Quadratic Programming with Proportioning
		   and Projections },
 journal	= SIOPT,
 volume		= 7, number = 3, pages = {871--887}, year = 1997}

@article{DrusGreeKniz98,
 author		= {V. Druskin and A. Greenbaum and L. Knizherman},
 title		= {Using nonorthogonal {L}anczos vectors in the computation of
		   matrix functions},
 journal	= SISC,
 volume		= 19, number = 1, pages = {38--54}, year = 1998}

@book{DuffErisReid86,
 author		= {I. S. Duff and A. M. Erisman and J. K. Reid},
 title		= {Direct Methods for Sparse Matrices},
 publisher	= OUP, address = OUP-ADDRESS,
 year		= 1986}

@article{DuffNoceReid87,
 author		= {I. S. Duff and J. Nocedal and J. K. Reid},
 title		= {The use of linear programming for the solution of sparse
		   sets of nonlinear equations},
 journal	= SISSC,
 volume		= 8, number = 2, pages = {99--108}, year = 1987,
 abstract	= {In this paper, we propose a trust region algorithm for
		   solving sparse sets of nonlinear equations. It is based on
		   minimizing the $\ell_1$-norm of the linearized residual
		   within an $\ell_{\infty}$-norm trust region, thereby
		   permitting linear programming techniques to be easily
		   applied. The new algorithm has sparsity advantages over the
		   \citebb{Leve44}--\citebb{Marq63} algorithm},
 summary	= {A trust-region algorithm for solving sparse sets of
		   nonlinear equations is proposed. It is based on minimizing
		   the $\ell_1$-norm of the linearized residual within an
		   $\ell_{\infty}$-norm trust region, thereby permitting
		   linear programming techniques to be applied. The algorithm
		   has sparsity advantages over the
		   Levenberg-Morrison-Marquardt algorithm}}

@inproceedings{Duff97,
 author		= {I. S. Duff},
 title		= {Sparse numerical linear algebra: direct methods and
		   preconditioning},
 crossref	= {DuffWats97}, pages = {27--62}}

@article{DuffReid83b,
 author		= {I. S. Duff and J. K. Reid},
 title		= {The multifrontal solution of indefinite sparse symmetric
		   linear equations},
 journal	= TOMS,
 volume		= 9, number = 3, pages = {302--325}, year = 1983}

@article{DuffReid96b,
 author		= {I. S. Duff and J. K. Reid},
 title		= {Exploiting zeros on the diagonal in the direct solution of
		   indefinite sparse symmetric linear systems},
 journal	= TOMS,
 volume		= 22, number = 2, pages = {227--257}, year = 1996}
                                                         
@article{DuffReidMunkNeil79,
 author		= {I. S. Duff and J. K. Reid and N. Munksgaard and H. B.
		   Neilsen},
 title		= {Direct solution of sets of linear equations whose matrix is
		   sparse, symmetric and indefinite},
 journal	= JIMA,
 volume		= 23, pages = {235--250}, year = 1979}

@article{Dunn80,
 author		= {J. C. Dunn},
 title		= {{N}ewton's method and the {G}oldstein step-length rule for
		   constrained minimization problems},
 journal	= SICON,
 volume		= 6, pages = {659--674}, year = 1980}

@article{Dunn87,
 author		= {J. C. Dunn},
 title		= {On the convergence of projected gradient processes to
		   singular critical points},
 journal	= JOTA,
 volume		= 55, pages = {203--216}, year = 1987}

@article{DussFerlLema86,
 author		= {J. P. Dussault and J. A. Ferland and B. Lemaire},
 title		= {Convex quadratic programming with one constraint and
		   bounded variables},
 journal	= MP,
 volume		= 36, number = 1, pages = {90--104}, year = 1986}

%%% E %%%

@article{EckeNiem75,
 author         = {J. G. Ecker and R. D. Niemi},
 title          = {A dual method for quadratic programs with quadratic
                   constraints},
 journal        = SIAPM,
 volume         = 28, number = 3, pages = {568--576}, year = 1975,
 abstract       = {A dual method is developed for minimizing a convex
                   quadratic function of several variables subject to
                   inequality constraints on the same type of function. The
                   dual program is a concave maximization problem with
                   constraints that are essentially linear.
                   However, the dual objective function is not differentiable
                   over the dual constraint region. The numerical
                   difficulties associated with this nondifferentiability are
                   circumvented by considering a sequence of dual programs via
                   a modified penalty function technique that does not
                   eliminate the dual constraints but does insure that they
                   will all be active at optimality. A numerical example is
                   included.},
 summary        = {A dual method is developed for minimizing a convex
                   quadratic function of several variables subject to
                   inequality constraints on the same type of function. The
                   method solves a sequence of dual programs via
                   a modified penalty function technique that does not
                   eliminate the dual constraints but ensures that they
                   will be active at optimality. A numerical example is
                   included.}}

@article{Ecks93,
 author		= {J. Eckstein},
 title		= {Nonlinear Proximal Point Algorithms Using {B}regman
		   Functions with Applications to Convex Programming},
 journal	= MOR,
 volume		= 18, number = 1, pages = {202--226}, year = 1993}

@article{Edlu97,
 author		= {O. Edlund},
 title		= {Linear {M}-estimation with bounded variables},
 journal	= {BIT},
 volume		= 37, number = 1, pages = {13--23}, year = 1997,
 abstract	= {A subproblem in the trust region algorithm for non-linear
		   M-estimation by \citebb{EkblMads89} is to find the
		   restricted step. It is found by calculating the M-estimator
		   of the linearized model, subject to an $\ell_2$-norm bound
		   on the variables. In this paper it is shown that this
		   subproblem can be solved by applying \citebb{Hebd73}
		   iterations to the minimizer of the Lagrangian function. The
		   new method is compared with an Augmented Lagrange
		   implementation.},
 summary	= {A subproblem in the trust-region algorithm for nonlinear
		   M-estimation by \citebb{EkblMads89} is to find the
		   restricted step, by calculating the M-estimator of the
		   linearized model, subject to an $\ell_2$-norm bound on the
		   variables. It is shown that this subproblem can be solved
		   by applying \citebb{Hebd73} iterations to the minimizer of
		   the Lagrangian function. The method is compared with an
		   Augmented Lagrange implementation.}}

@article{EdluEkblMads97,
 author		= {O. Edlund and H. Ekblom and K. Madsen},
 title		= {Algorithms for non-linear {M}-estimation},
 journal	= {Computational Statistics},
 volume		= 12, number = 3, pages = {373--383}, year = 1997,
 abstract	= {In non-linear regression, the least squares method is most
		   often used. Since this estimator is highly sensitive to
		   outliers in the data, alternatives have become increasingly
		   popular during the last decades. We present algorithms for
		   non-linear M-estimation. A trust region approach is used,
		   where a sequence of estimation problems for linearized
		   models is solved. In the testing we apply four estimators
		   to ten non-linear data fitting problems. The test problems
		   are also solved by the Generalized
		   \citebb{Leve44}--\citebb{Marq63} method and standard
		   optimization BFGS method. It turns out that the new method
		   is in general more reliable and efficient.},
 summary	= {Algorithms for nonlinear M-estimation are presented. A
		   trust-region approach is used, where a sequence of
		   estimation problems for linearized models is solved.
		   Numerical tests involving four estimators and ten
		   non-linear data fitting problems are performed.}}

@article{EdsbWedi95,
 author		= {L. Edsberg and P. A. Wedin},
 title		= {Numerical tools for parameter-estimation in {ODE} systems},
 journal	= {Optimization Methods and Software},
 volume		= 6, number = 3, pages = {193--217}, year = 1995,
 abstract	= {The numerical problem of estimating unknown parameters in
		   systems of ordinary differential equations from complete or
		   incomplete data is treated. A new numerical method for the
		   optimization part, based on the Gauss-Newton method with a
		   trust region approach to subspace minimization for the
		   weighted nonlinear least squares problem, is presented. The
		   method is implemented in the framework of a toolbox (called
		   diffpar) in Matlab and several test problems from
		   applications, giving non-stiff and stiff ODE-systems, are
		   treated.},
 summary	= {The numerical problem of estimating unknown parameters in
		   systems of ordinary differential equations from complete or
		   incomplete data is treated. A numerical method for the
		   optimization part is presented, based on the Gauss-Newton
		   method with a trust-region approach to subspace
		   minimization for the weighted nonlinear least-squares
		   problem. The method is implemented in Matlab and several
		   test problems from applications, giving non-stiff and stiff
		   ODE-systems, are treated.}}

@misc{EinaMads98,
 author         = {H. Einarsson and K. Madsen},
 title          = {Cutting planes and trust-regions for nondifferentiable
                   optimization},
 howpublished	= {Presentation at the International Conference on Nonlinear
                   Programming and Variational Inequalities, Hong Kong},
 year		= 1998,
 abstract       = {We discuss the problem of minimizing a nonsmooth function
                   $f:\Re^n \righarrow \Re$. $f$ is assumed to be continuous
                   and piecewise smooth, and the number of sooth pieces is
                   assumed to be finite.  The bundle trust region method of
                   \citebb{SchrZowe92}, is discussed.  it is shown that in 
                   the neighbourhood of a minimizer the general function $f$
                   may be considered as a minimax function, and the relation
                   between the cutting plane methods of \citebb{SchrZowe92}
                   and the minimax trust region method of \citebb{Mads75} is
                   discussed. Based on these ideas an iterative method for
                   minimizing $f$ is proposed. The basic principles are the
                   following.  At each iteration $f$ is approximated by a
                   piecewise linear minimax function which is intended to
                   model the set of generalized gradients in the neighbourhood
                   of the current iterate.  Two trust regions are used: an
                   inner $R_i$ in which the piecewise linear approximation to
                   $f$ is found, and an outer $R_o$ in which the next tentative
                   step is calculated.  Initially the two trust regions are
                   equal, but if the iterate is close to a kink (i.e.\ the
                   intersection between two or more smooth pieces) then the
                   inner trust region radius may be smaller.  The method has
                   been tested on a number of convex as well as nonconvex test
                   problems, and the results are compared with those of
                   \citebb{SchrZowe92}.  Some of the test problems are of the
                   minimax or $L_1$ type, and in these cases the new algorithm
                   is compared with the dedicated methods of \citebb{Mads75}
                   and Hald and Madsen (1985).},
 summary        = {A bundle trust-region method is proposed for the
                   minimization of piecewise smooth functions. At each
                   iteration $f$ is approximated by a piecewise linear minimax
                   function that models the set of generalized gradients in
                   the neighbourhood of the current iterate.  Two trust regions
                   are used: an inner one in which the piecewise linear
                   approximation to the objective function is found, and an
                   outer one in which the trial step is calculated.  Initially
                   the two radii are equal, but the inner radius may be smaller
                   if the iterate is close to a the intersection between
                   smooth pieces. The method is tested on convex and non-convex
                   test problems}}

@techreport{EiseWalk94,
 author		= {S. C. Eisenstat and H. F. Walker},
 title		= {Choosing the forcing terms in an inexact {N}ewton method},
 institution	= {Dept of Mathematics and Statistics, Utah State University},
 address	= {Logan, USA},
 number		= {6/94/75}, year = 1994}

@book{Eispack76,
 author		= {B. T. Smith and J. M. Boyle and J. J. Dongarra and B. S.
		   Garbow and Y. Ikebe and V. C. Klema and C. B. Moler},
 title		= {Matrix Eigensystem Routine---EISPACK Guide},
 publisher	= SPRINGER, address = SPRINGER-ADDRESS,
 year		= 1976}

@article{EkblMads89,
 author		= {H. Ekblom and K. Madsen},
 title		= {Algorithms for non-linear {H}uber estimation},
 journal	= BIT,
 volume		= 29, number = 1, pages = {60--76}, year = 1989,
 abstract       = {The Huber criterion for data fitting is a combination
                   of the $\ell_1$ and the $\ell_2$ criteria which is
                   robust in the sense that the influence of ``wild'' data
                   points can be reduced. The authors present a trust
                   region and a Marquardt algorithm for Huber estimation
                   in the case where the functions used in the fit are
                   nonlinear. It is demonstrated that the algorithms
                   converge under the usual conditions.},
 summary        = {A converfent Levenberg-Morrison-Marquardt method for
		   nonlinear Huber estimation is presented.}}

@techreport{ElAl88,
 author		= {M. El{-}Alem},
 title		= {A Global Convergence Theory for a Class of Trust Region
		   Algorithms for Constrained Optimization},
 institution	= CAAM, address = RICE-ADDRESS,
 number		= {TR88-5}, year = 1988,
 abstract	= {In this research, we present a trust region algorithm for
		   solving the equality constrained optimization problem. This
		   algorithm is a variant of the \citebb{CeliDennTapi85}
		   algorithm. The augmented Lagrangian function is used as a
		   merit function. A scheme for updating the penalty parameter
		   is presented. The behavior of the penalty parameter is
		   discussed. We present a global and local convergence
		   analysis for this algorithm. We also show that under mild
		   assumptions, in a neighborhood of the minimizer, the
		   algorithm will reduce to the standard SQP algorithm; hence
		   the local rate of convergence of SQP is maintained. Our
		   global convergence theory is sufficiently general that it
		   holds for any algorithm that generates steps that give at
		   least a fraction of Cauchy decrease in the quadratic model
		   of constraints.},
 summary	= {A variant of the \citebb{CeliDennTapi85} trust-region
		   algorithm for equality constrained optimization is given.
		   An augmented Lagrangian merit function is used, and a
		   scheme for updating the penalty parameter presented.
		   A global and local convergence
		   analysis is given, showing that
		   the algorithm reduces to the standard SQP algorithm in a
		   neighborhood of the minimizer. The global convergence
		   theory is sufficiently general that it holds for any
		   algorithm that generates steps giving at least a
		   fraction of Cauchy decrease in the quadratic model of
		   constraints.}}

@article{ElAl91,
 author		= {M. El{-}Alem},
 title		= {A global convergence theory for the
		   {D}ennis-{C}elis-{T}apia trust-region algorithm for
		   constrained optimization},
 journal	= SINUM,
 volume		= 28, number = 1, pages = {266--290}, year = 1991,
 abstract	= {A global convergence theory for a class of trust-region
		   algorithms for solving the equality constrained
		   optimization problem is presented. This theory is
		   sufficiently general that it holds for any algorithm that
		   generates steps giving at least a fraction of Cauchy
		   decrease in the quadratic model of the constraints, and
		   that uses the augmented Lagrangian as a merit function.
		   This theory is used to establish global convergence of the
		   \citebb{CeliDennTapi85} algorithm with a different scheme
		   for updating the penalty parameter. The behaviour of the
		   penalty parameter is also discussed.},
 summary	= {A global convergence theory for a class of trust-region
		   algorithms for equality constrained optimization is
		   presented, that holds for any algorithm that generates
		   steps giving at least a fraction of Cauchy decrease in the
		   quadratic model of the constraints, and that uses the
		   augmented Lagrangian as a merit function. This theory is
		   used to establish global convergence of the
		   \citebb{CeliDennTapi85} algorithm with a different scheme
		   for updating the penalty parameter. The behaviour of the
		   penalty parameter is also discussed.}}

@article{ElAl95,
 author		= {M. El{-}Alem},
 title		= {A Robust Trust-Region Algorithm with a Nonmonotonic Penalty
		   Parameter Scheme for Constrained Optimization},
 journal	= SIOPT,
 volume		= 5, number = 2, pages = {348--378}, year = 1995,
 abstract	= {An algorithm for solving the problem of minimizing a
		   non-linear function subject to equality constraints is
		   introduced. This algorithm is a trust-region algorithm. In
		   computing the trial step, a projected-Hessian technique is
		   used that converts the trust-region subproblem to a one
		   similar to that of the unconstrained case. To force global
		   convergence, the augmented Lagrangian is empoyed as a merit
		   function. One of the main advantages of this algorithm is
		   the way that the penalty parameter is updated. We introduce
		   an updating scheme that allows (for the first time to the
		   best of our knowledge) the penalty parameter to be
		   decreased whenever it is warranted. The behaviour of this
		   penalty parameter is studied. A convergence theory for this
		   algorithm is presented. It is shown that this algorithm is
		   globally convergent and that the globalization strategy
		   will not disrupt fast local convergence. The local rate of
		   convergence is also discussed. This theory is sufficiently
		   general that it holds for any algorithm that generates
		   steps whose normal component give at least a fraction of
		   the Cauchy decrease in the quadratic model of the
		   constraints and uses \citebb{Flet70b}'s exact penalty
		   function as a merit function.},
 summary	= {A trust-region algorithm for nonlinear optimization subject
		   to equality constraints is introduced. In computing the
		   trial step, a projected-Hessian technique converts the
		   trust-region subproblem to one similar to that of the
		   unconstrained case. To force global convergence, the
		   augmented Lagrangian is employed as a merit function. An
		   updating scheme that allows the penalty parameter to be
		   decreased whenever it is warranted is proposed, and the its
		   behaviour is studied. It is shown that this algorithm is
		   globally convergent and that the globalization strategy
		   does not disrupt fast local convergence. The local rate of
		   convergence is also discussed. This theory is sufficiently
		   general that it holds for any algorithm that generates
		   steps whose normal component give at least a fraction of
		   the Cauchy decrease in the quadratic model of the
		   constraints and uses \citebb{Flet70b}'s exact penalty
		   function as a merit function.}}

@article{ElAl95b,
 author		= {M. El{-}Alem},
 title		= {Global convergence without the assumption of linear
		   independence for a trust-region algorithm for constrained
		   optimization},
 journal	= JOTA,
 volume		= 87, number = 3, pages = {563--577}, year = 1995,
 abstract	= {A trust-region algorithm for solving the equality
		   constrained optimization problem is presented. This
		   algorithm uses the Byrd and \citebb{Omoj89} way of
		   computing the trial steps, but it differs from the Byrd and
		   Omojokun algorithm in the way steps are evaluated. A global
		   convergence theory for this new algorithm is presented. The
		   main feature of this theory is that the linear independence
		   assumption on the gradients of the constraints is not
		   assumed.},
 summary	= {A trust-region algorithm for solving the equality
		   constrained optimization problem is presented. This
		   algorithm uses the Byrd and \citebb{Omoj89} mechanism for
		   computing the trial steps, but it differs from this
		   algorithm in the way steps are evaluated. Global
		   convergence is proved without assuming linear independence
		   of the constraints' gradients.}}

@article{ElAl96,
 author		= {M. El{-}Alem},
 title		= {Convergence to a 2nd order point of a trust-region
		   algorithm with nonmonotonic penatly parameter for
		   constrained optimization},
 journal	= JOTA,
 volume		= 91, number = 1, pages = {61--79}, year = 1996,
 abstract	= {In a recent paper, the author proposed a trust-region
		   algorithm for solving the problem of minimizing a nonlinear
		   function subject to a set of equality constraints. The main
		   feature of the algorithm is that the penalty parameter in
		   the merit function can be decreased whenever it is
		   warranted. He studied the behavior of the penalty parameter
		   and proved several global and local convergence results.
		   One of these results is that there exists a subsequence of
		   the iterates generated by the algorithm that converges to a
		   point that satisfies the first-order necessary conditions.
		   In the current paper, we show that, for this algorithm,
		   there exists a subsequence of iterates that converges to a
		   point that satisfies both the first-order and the
		   second-order necessary conditions.},
 summary	= {It is shown that a subsequence of iterates produced by the
		   trust-region algorithm of \citebb{ElAl95} converges to a
		   point that satisfies both the first- and second-order
		   necessary conditions.}}
%also 
%institution = CRPC, address = RICE-ADDRESS,
%number         = {CRPC-TR96654}, year = 1996,

@article{ElAl99,
 author		= {M. El{-}Alem},
 title		= {A Global Convergence Theory for a General Class of
		   Trust-Region-Based Algorithms for Constrained Optimization
		   Without Assuming Regularity},
 journal        = SIOPT,
 volume         = 9, number = 4, pages = {965--990}, year = 1999,
 abstract	= {This work presents a convergence theory for a general class
		   of trust-region-based algorithms for solving the smooth
		   nonlinear programming problem with equality constraints.
		   The results are proved under very mild conditions on the
		   quasi-normal and tangential components of the trial steps.
		   The Lagrange multiplier estimates and the Hessian estimates
		   are assumed to be bounded. In addition, the regularity
		   assumption is not made. In particular, the linear
		   independence of the gradients of the constraints is not
		   assumed. The theory proves global convergence to one of
		   four different types of Mayer-Bliss stationary points. The
		   theory holds for any algorithm that uses the augmented
		   Lagrangian as a merit function, the \citebb{ElAl95} scheme
		   for updating the penalty parameter, and bounded multiplier
		   and Hessian estimates.},
 summary	= {A convergence theory is presented for a general class of
		   trust-region algorithms for solving the smooth nonlinear
		   programming problem with equality constraints. The results
		   are proved under very mild conditions on the quasi-normal
		   and tangential components of the trial steps. The Lagrange
		   multiplier estimates and the Hessian estimates are assumed
		   to be bounded. In addition, no regularity assumption, such
		   as linear independence of the constraints' gradients, is
		   made. The theory proves global convergence to one of four
		   different types of Mayer-Bliss stationary points, and holds
		   for any algorithm that uses the augmented Lagrangian as a
		   merit function, the \citebb{ElAl95} scheme for updating the
		   penalty parameter, and bounded multiplier and Hessian
		   estimates.}}
%also 
%institution = CRPC, address = RICE-ADDRESS,
%number         = {CRPC-TR96655}, year = 1996,

@techreport{ElAl96c,
 author		= {M. El{-}Alem},
 title		= {A Strong Global Convergence Result for {D}ennis,
		   {E}l-{A}lem, and {M}aciel's Class of Trust Region
		   Algorithms},
 institution	= CAAM, address = RICE-ADDRESS,
 number		= {TR96-15}, year = 1996,
 abstract	= {In a recent paper, \citebb{DennElAlMaci97} suggested a
		   class of trust-region-based algorithms for solving the
		   equality constrained optimization problem. They established
		   a global convergence result that is analogous to
		   \citebb{Powe75}'s result for the unconstrained optimization
		   problem. In this paper, a global convergence theory for
		   \citebbs{DennElAlMaci97} class of algorithms is presented.
		   The theory is analogous to \citebb{Thom75}'s result for
		   unconstrained optimization. In particular, it proves that
		   every accumulation point of the sequence of iterates
		   generated by any member of \citebbs{DennElAlMaci97} class
		   of algorithms is a first-order point. In other words, the
		   sequence of iterates converges to the set of first-order
		   points of the problem. To the best of our knowledge, the
		   global convergence result presented in this paper
		   generalizes all existing global convergence theories for
		   trust region algorithms that are suggested for solving the
		   equality constrained optimization problem and use the
		   augmented Lagrangian as a merit function.},
 summary	= {A global convergence theory for \citebb{DennElAlMaci97}'s
		   class of algorithms is presented, which is analogous to
		   \citebb{Thom75}'s result for unconstrained optimization. In
		   particular, every accumulation point of the sequence of
		   iterates is a first-order stationary point. This
		   result generalize all current global convergence theories
		   for trust-region algorithms that have been suggested for
		   solving the equality constrained optimization problem and
		   use the augmented Lagrangian as a merit function.}}
%also 
%institution = CRPC, address = RICE-ADDRESS,
%number         = {CRPC-TR96656}, year = 1996,

@article{ElAlTapi95,
 author		= {M. El{-}Alem and R. A. Tapia},
 title		= {Numerical Experience with a polyhedral-norm {CDT}
		   trust-region algorithm},
 journal	= JOTA,
 volume		= 85, number = 3, pages = {575--591}, year = 1995,
 abstract	= {In this paper, we study a modification of the
		   \citebb{CeliDennTapi85} trust-region subproblem, which is
		   obtained by replacing the $l_2$-norm with a polyhedral
		   norm. The polyhedral norm Celis-Dennis-Tapia (CDT)
		   subproblem can be solved using a standard quadratic
		   programming code. We include computational results which
		   compare the performance of the polyhedral-norm CDT
		   trust-region algorithm with the performance of existing
		   codes. The numerical results validate the effectiveness of
		   the approach. These results show that there is not much
		   loss of robustness or speed and suggest that the
		   polyhedral-norm CDT algorithm may be a viable alternative.
		   The topic merits further investigation.},
 summary	= {A modification of the \citebb{CeliDennTapi85} (CDT)
		   trust-region subproblem, which is obtained by replacing the
		   $l_2$-norm with a polyhedral norm, is studied. The
		   polyhedral norm CDT subproblem can be solved using a
		   standard quadratic programming code. Computational results
		   which compare the performance of the polyhedral-norm CDT
		   trust-region algorithm with the performance of existing
		   codes are given.}}

@article{ElBa98,
 author		= {A. S. El{-}Bakry},
 title		= {Convergence rate of primal-dual reciprocal barrier {N}ewton
		   interior-point methods},
 journal	= OMS,
 volume         = 9, number = {1--3}, pages = {37--44}, year = 1998}

@techreport{ElHa87,
 author		= {M. El{-}Hallabi},
 title		= {A Global Convergence Theory for Arbitrary Norm Trust Region
		   Methods for Nonlinear Equations},
 institution	= CAAM, address = RICE-ADDRESS,
 number		= {TR87-5}, year = 1987,
 abstract	= {In this research we extend the
		   \citebb{Leve44}--\citebb{Marq63} algorithm for
		   approximating zeros of the nonlinear system $F(x)=0$, where
		   $F$ is continuously differentiable from $\Re^n$ to $\Re^n$.
		   Instead of the $\ell_2$-norm, arbitrary norms can be used
		   in the objective function and in the trust region
		   constraint. The algorithm is shown to be globally
		   convergent. This research was motivated by the recent work
		   of \citebb{DuffNoceReid87}. A key point in our analysis is
		   that the tools from nonsmooth analysis, namely locally
		   Lipschitz analysis, allow us to establish essentially the
		   same properties for our algorithm that have been
		   established for the \citebb{Leve44}--\citebb{Marq63}
		   algorithm using the tools from smooth optimization. In our
		   analysis, the sequence generated by the algorithm is the
		   couple $(x_k, \delta_k)$ where $x_k$ is the iterate and
		   $\delta_k$ the trust region radius. Since the successor
		   $(x_{k+1}, \delta_{k+1})$ of $(x_k,\delta_k)$ is not unique
		   we model our algorithm by a point-to-set map and then apply
		   Zangwill's theorem of convergence to our case. It is shown
		   that our algorithm reduces locally to Newton's method.},
 summary	= {The Levenberg-Morrison-Marquardt algorithm for
		   approximating zeros of the nonlinear system $F(x)=0$ is
		   generalized to allow the use of arbitrary norms
		   n the objective function and in the trust
		   region constraint. The algorithm, which is motivated by
		   that of \citebb{DuffNoceReid87}, is globally
		   convergent. Essentially the same properties apply for the
		   general and for the Levenberg-Morrison-Marquardt algorithm. 
		   In this analysis, the sequence generated is
		   the couple $(x_k, \Delta_k)$ where $x_k$ is the iterate and
		   $\Delta_k$ the trust region radius. Since the successor
		   $(x_{k+1}, \Delta_{k+1})$ of $(x_k,\Delta_k)$ is not unique
		   the algorithm is modelled by a point-to-set map and then
		   Zangwill's convergence theorem is applied. The algorithm
		   locally reduces to Newton's method.}}

@techreport{ElHa90,
 author		= {M. El{-}Hallabi},
 title		= {A Global Convergence Theory for A Class of Trust-Region
		   Methods for Nonsmooth Optimization.},
 institution	= CAAM, address = RICE-ADDRESS,
 number		= {TR90-10}, year = 1990,
 abstract	= {In this work we define a class of trust-region algorithms
		   for approximating a minimizer of the function $f=h(F)$
		   where $F: \Re^n \rightarrow \Re^m$ is continuously
		   differentiable and $h=\Re^m \rightarrow \Re$ is regular
		   locally Lipschitz. We show that algorithms from this class
		   are globally convergent. Our analysis is a generalization
		   of the recent work of \citebb{ElHaTapi93} and can be
		   applied to most algorithms in the literature. Our
		   algorithms are a natural generalization of those for smooth
		   minimization to nonsmooth optimization.},
 summary	= {A class of trust-region algorithms is defined for
		   approximating a minimizer of the function $f=h(F)$ where
		   $F: \Re^n \rightarrow \Re^m$ is continuously differentiable
		   and $h=\Re^m \rightarrow \Re$ is regular locally Lipschitz.
		   Algorithms from this class are globally
		   convergent. The analysis is a generalization of that given
		   by \citebb{ElHaTapi93} and can be applied to most
		   algorithms in the literature. The algorithms are a natural
		   generalization of those for smooth minimization to
		   non-smooth optimization.}}

@techreport{ElHa93,
 author		= {M. El{-}Hallabi},
 title		= {An Inexact Minimization Trust-Region Algorithm:
		   globalization of {N}ewton's Method},
 institution	= CAAM, address = RICE-ADDRESS,
 number		= {TR93-43}, year = 1993,
 abstract	= {In this work we define a trust region algorithm for
		   approximating zeros of the nonlinear system $F(x)=0$, where
		   $F: \Re^n \rightarrow \Re^n$ is continuously
		   differentiable. We are concerned with the fact that $n$ may
		   be large. So we replace the $\ell_2$ norm with arbitrary
		   norms in the objective function and in the trust region
		   constraint. In particular, if polyhedral norms are used,
		   then the algorithm can be viewed as a sequential linear
		   programming algorithm. At each iteration, the local
		   trust-region model is only solved within some tolerance.
		   This research is an extension of \citebb{ElHaTapi93} for
		   nonlinear equations, where an exact solution of the local
		   model was required. We demonstrate that the algorithm under
		   consideration is globally convergent, and that, under mild
		   assumptions, the iteration sequence generated by the
		   algorithm converges to a solution of the nonliner system.
		   We also demonstrate that, under the standard assumptions
		   for Newton's method theory, the rate of convergence is
		   $q$-superlinear. Moreover, quadratic convergence can be
		   obtained by requiring sufficient accuracy in the solution
		   of the local model.},
 summary	= {A trust-region algorithm generalizing that of
		   \citebb{ElHaTapi93} is given, in which the trust-region
		   subproblem can be solved approximately. The algorithm
		   considered is globally convergent and its
		   rate of convergence is $Q$-superlinear. Quadratic
		   convergence can be obtained by requiring sufficient
		   accuracy in the solution of the local model.}}

@techreport{ElHa99,
 author		= {M. El{-}Hallabi},
 title          = {Globally Convergent Multi-Level Inexact Hybrid Algorithm
                   for Equality Constrained Optimization},
 institution    = {D\'{e}partement Informatique et Optimisation, Institut 
                   National des Postes et T\'{e}l\'{e}communications},
 address        = {Rabat, Morocco},
 number         = {RT11-98(revised)}, year = 1999,
 abstract       = {Trust-region globalization strategies have proved to be
                   powerful tools to design globally convergent algorithms, 
                   but at the cost of allowing the local model to be solved
                   more than once at each iteration.  On the other hand,
                   beside their poor global convergence properties, linesearch
                   strategies are quite popular for their low cost of
                   obtaining an acceptable steplength whenever a search
                   direction is provided.  In this paper we aim to combine
                   both strategies in a globally convergent multi-level
                   inexact hybrid algorithm to minimize a contunuouly
                   differentiable nonlinear function $f: \Re^n \rightarrow \Re$
                   subject to equality constraint $h_i(x)=0$, $i=1,\ldots,m$
                   where $h_i:\Re^n \rightarrow \Re$ are continuously
                   differentiable.  First, the trust-region approach is used
                   to determine a trial step that is shown to ne a descent
                   direction of the merit function, and second, linesearch
                   techniques are used to obtain an acceptable steplength
                   in such a direction.  We prove that the hybrid algorithm
                   is globally convergent in the sense that any accumulation
                   point of the iteration sequence is a Karush-Kuhn-Tucker
                   point of the minimization problem.  In our algorithm, the
                   curvature of the local model is taken into account first,
                   to obtain the trial step direction and second, to accept
                   or reject the steplength.  Both tests are less conservative
                   than the usual ones.  Also, we prove that the penalty
                   parameter is uniformly bounded away from zero at
                   nonstationary points, instead of forcing the trust-region
                   radius to be initialized, at each iteration, as large as
                   some given positive $\delta_{\min}$, we show that the
                   internal trust-region increasing strategy, a technique
                   quite popular for preventing large numbers of gradient and
                   Hessian evaluations, yields the same important property.
                   Furthermore, we show that the steplength is bounded away
                   from zero at nonstaionary points.  We do not use the
                   regularity assumption of linear independent gradients. 
                   On the other hand, we assume that $h(x_k)$ does not belong
                   to the nullspace of $\nabla h(x_k)$ for non feasible
                   iterates.  Moreover, we assume that if 
                   $\{x_k\mid k \in N\subset\calN\}$ is a subsequence
                   converging to some accumulation point of the iteration
                   sequence, say $x_*$, then the normalized constraint vector
                   is uniformly bounded away from the nullspace of
                   $\nabla h(x_k)$.},
 summary        = {The combination of linesearch and trust-region techniques
                   is investigated in the context of problems with equality
                   constraints. Beneficial effects of internal doubling in
                   this context are also discussed, together with an
                   alternative expression of constraint qualification.}}

@techreport{ElHaTapi93,
 author		= {M. El{-}Hallabi and R. A. Tapia},
 title		= {A Global Convergence Theory for Arbitrary Norm Trust-Region
		   Methods for Nonlinear Equations},
 institution	= CAAM, address = RICE-ADDRESS,
 number		= {TR93-41}, year = 1993,
 abstract	= {In this work, we extend the Levenberg-Marquardt algorithm
		   for approximating zeros of the nonlinear system $F(x)=0$,
		   where $F: \Re^n \rightarrow \Re^n$ is continuously
		   differentiable. Instead of the $\ell_2$ norm, arbitrary
		   norms can be used in the trust-region constraint. The
		   algorithm is shown to be globally convergent. This research
		   is motivated by the recent work of \citebb{DuffNoceReid87}.
		   A key point in our analysis is that the tools from
		   nonsmooth analysis and the Zangwill convergence theory
		   allow us to establish essentially the same properties for
		   an arbitrary trust-region algorithm that have been
		   established for the Levenberg-Marquardt algorithm using the
		   tools from smooth optimization. It is shown that all
		   members of this class of algorithms locally reduce to
		   Newton's method and that the iteration sequence actually
		   converges to a solution.},
 summary	= {The Levenberg-Morrison-Marquardt algorithm for
		   approximating zeros of the nonlinear system $F(x)=0$, where
		   $F: \Re^n \rightarrow \Re^n$ is continuously
		   differentiable, is extended. Arbitrary norms can be used in
		   place of the $\ell_2$-norm for the trust-region constraint.
		   The algorithm is  globally convergent. This
		   algorithm is motivated by the work of
		   \citebb{DuffNoceReid87}. It locally reduce to Newton's
		   method and the iteration sequence converges to a
		   solution.}}

@techreport{ElHaTapi95,
 author		= {M. El{-}Hallabi and R. A. Tapia},
 title		= {An Inexact Trust-Region Feasible-Point Algorithm for
		   Nonlinear Systems of Equalities and Inequalities},
 institution	= CAAM, address = RICE-ADDRESS,
 number		= {TR95-09}, year = 1995,
 abstract	= {In this work we define a trust-region feasible-point
		   algorithm for approximating solutions of the nonlinear
		   system of equalities and inequalities $F(x, y)=0, y \ge 0$,
		   where $F: { \Re^n \times \Re^m } \rightarrow \Re^p$ is
		   continuously differentiable. This formulation is quite
		   general; the Karush-Kuhn-Tucker conditions of a general
		   nonlinear programming problem are an obvious example, and a
		   set of equalities and inequalities can be transformed,
		   using slack variables, into such form. We will be concerned
		   with the possibility that $n$, $m$ and $p$ may be large and
		   that the Jacobian matrix may be sparse and rank deficient.
		   Exploiting the convex structure of the local model
		   trust-region subproblem, we propose a globally convergent
		   inexact trust-region feasible-point algorithm to minimize
		   an arbitrary norm of the residual, say $\| F(x, y)\|_a$,
		   subject to the nonnegativity constraints. This algorithm
		   uses a trust-region globalization strategy to determine a
		   descent direction as an inexact solution of the local model
		   trust-region subproblem and then, it uses linesearch
		   techniques to obtain an acceptable steplength. We
		   demonstrate that, under rather weak hypotheses, any
		   accumulation point of the iteration sequence is a
		   constrained stationary point for $f=\|F\|_a$, and that the
		   sequence of constrained residuals converges to zero.},
 summary	= {A feasible-point trust-region algorithm for approximating
		   solutions of the nonlinear system of equalities and
		   inequalities $F(x, y)=0, y \ge 0$, where $F: { \Re^n \times
		   \Re^m } \rightarrow \Re^p$ is continuously differentiable,
		   is considered. By exploiting the convex structure of the
		   local trust-region subproblem, a globally convergent
		   inexact trust-region feasible-point algorithm is suggested
		   for minimizing an arbitrary norm of the residual, 
		   $\| F(x, y)\|_a$, subject to non-negativity constraints. This
		   algorithm uses a descent direction which is an inexact
		   solution of the trust-region subproblem and then uses
		   linesearch techniques to obtain an acceptable steplength.
		   It is shown that, under weak hypotheses, any accumulation
		   point of the iteration sequence is a constrained stationary
		   point for $f=\|F\|_a$, and that the sequence of constrained
		   residuals converges to zero.}}

@article{ElstNeum97,
 author		= {C. Elster and A. Neumaier},
 title		= {A method of trust region type for minimizing noisy
		   functions},
 journal	= {Computing},
 volume		= 58, number = 1, pages = {31--46}, year = 1997,
 abstract	= {The optimization of noisy functions in a few variables only
		   is a common problem occurring in various applications, for
		   instance in finding the optimal choice of a few control
		   parameters in chemical experiments. The traditional tool
		   for the treatment of such problems is the method of
		   \citebb{NeldMead65} (NM). In this paper, an alternative
		   method based on a trust region approach (TR) is offered and
		   compared to NM. On the standard collection of test
		   functions for unconstrained optimization by
		   \citebb{MoreGarbHill81}, TR performs substantially more
		   robust than NM. If performance is measured by the number of
		   function evaluations, TR is on the average twice as fast as
		   NM.},
 summary	= {The optimization of noisy functions of a few variables is a
		   commonly occurring problem in application areas such as
		   finding the optimal choice of a few control parameters in
		   chemical experiments. The traditional tool for the
		   treatment of such problems is the method of
		   \citebb{NeldMead65} (NM). An alternative method based on a
		   trust-region approach (TR) is proposed and compared to NM.
		   On a standard collection of test functions for
		   unconstrained optimization by \citebb{MoreGarbHill81}, TR
		   is substantially more robust than NM. If performance is
		   measured by the number of function evaluations, TR is seen
		   to be, on average, twice as fast as NM.}}

@article{EskoSchn91,
 author		= {E. Eskow and R. B. Schnabel},
 title		= {Algorithm 695: software for a new modified {C}holesky
		   factorization},
 journal	= TOMS,
 volume		= 17, number = 3, pages = {306--312}, year = 1991}

@article{Evan68,
 author		= {D. J. Evans},
 title		= {The use of pre-conditioning in iterative methods for
		   solving linear equations with positive definite matrices},
 journal	= JIMA,
 volume		= 4, pages = {295--314}, year = 1968}

%%% F %%%

@article{FaccLuci93,
 author		= {F. Facchinei and S. Lucidi},
 title		= {Nonmonotone Bundle-Type Scheme for Convex Nonsmooth
		   Minimization},
 journal	= JOTA,
 volume		= 76, number = 2, pages = {241--257}, year = 1993}

@inproceedings{FaccFiscKanz97,
 author		= {F. Facchinei and A. Fischer and Ch. Kanzow},
 title		= {A Semismooth {N}ewton Method for Variational Inequalities:
		   the Case of Box Constraints},
 crossref	= {FerrPang97}, pages = {76--90}}

@article{FaccKanz97,
 author		= {F. Facchinei and Ch. Kanzow},
 title		= {On unconstrained and constrained stationary points of the
		   implicit {L}agrangian},
 journal	= JOTA,
 volume		= 92, number = 1, pages = {99--115}, year = 1997}

@article{FaccSoar97,
 author		= {F. Facchinei and J. Soares},
 title		= {A new merit function for nonlinear complementarity problems
		   and a related algorithm},
 journal	= SIOPT,
 volume		= 7, number = 1, pages = {225--247}, year = 1997}

@article{FaccJudiSoar98,
 author		= {F. Facchinei and J. Judice and J. Soares},
 title		= {An active set {N}ewton algorithm for large-scale nonlinear
		   programs with box constraints},
 journal	= SIOPT,
 volume		= 8, number = 1, pages = { 158--186}, year = 1998,
 abstract	= {A new algorithm for large-scale nonlinear programs with box
		   constraints is introduced. The algorithm is based on an
		   efficient identification technique of the active set at the
		   solution and on a nonmonotone stabilization technique. It
		   possesses global and superlinear convergence properties
		   under standard assumptions. A new technique for generating
		   test problems with known characteristics is also
		   introduced. The implementation of the method is described
		   along with computational results for large-scale problems.},
 summary	= {An algorithm for large-scale nonlinear programs with box
		   constraints is introduced. The algorithm is based on an
		   efficient identification technique of the active set at the
		   solution and on a non-monotone stabilization technique. It
		   possesses global and superlinear convergence properties.
		   A technique for generating
		   test problems with known characteristics is also
		   introduced. The implementation of the method is described
		   along with computational results for large-scale problems.}}

@article{FanSarkLasd88,
 author         = {Y. Fan and S. Sarkar and L. S. Lasdon},
 title          = {Experiments with successive quadratic programming 
                   algorithms},
 journal        = JOTA,
 volume         = 56, number = 3, pages = {359--383}, year = 1988,
 abstract       = {There are many variants of successive quadratic
                   programming (SQP) algorithms. Important issues
                   include: the choice of either line search or trust
                   region strategies and the QP formulation to be used and
                   how the QP is to be solved. The authors consider the
                   QPs proposed by Fletcher and Powell and discuss a
                   specialized reduced-gradient procedure for solving
                   them. A computer implementation is described, and the
                   various options are compared on some well-known test
                   problems. Factors influencing robustness and speed
                   are identified.},
 summary        = {Important issues in SQP methods include the choice
		   of either linesearch or trust-region strategies and the
		   QP formulation to be used and how the QP is to be solved.
		   The QPs proposed by Fletcher and Powell are considered 
		   and a specialized reduced-gradient procedure discussed for
		   solving them. The various options are compared on some
		   well-known test problems.}}

@article{FeiHuan98,
 author		= {X. Fei and W. Huanchen},
 title		= {Integrated algorithm for bilevel nonsmooth 
                   optimization problems},
 journal	= {Journal of Shanghai Jiaotong University},
 volume		= 32, number = 12, pages = {115--119}, year = 1998,
 note		= {(in Chinese)},
 abstract	= {This paper is concerned with a kind of 1 leader-$N$ 
                   followers bilevel nonsmooth optimization problems.
                   An integrated algorithm is proposed which embeds
                   adaptively DFP into the inner iteration of the trust
                   region bundle method and makes the best use of the
                   global convergence of the bundle method and the local
                   fast convergence of the DFP. The Lipschitzian
                   property of functions involved is researched. An
                   approach of computing a subgradient of the objective
                   functions of the problems is investigated. The basic
                   idea and steps of the algorithm are
                   discussed. Finally, the convergence analysis is
                   given.},
 summary	= {A 1 leader-$N$ followers bilevel nonsmooth optimization 
                   problems is considered. A trust-region based bundle 
                   in which appropriate generailized second derivatives are 
                   obtained using a DFP-like formula is given, which
                   combines the global convergence properties of the 
                   bundle method with the fast local convergence properties
                   resulting from the use of approximate second derivatives.}}

@inproceedings{Felg97,
 author		= {U. Felgenhauer},
 title		= {Algorithmic stability analysis for certain trust region
		   methods},
 booktitle	= {Mathematical Programming with Data Perturbations},
 editor		= {A. V. Fiacco},
 publisher	= {Marcel Dekker, Inc.}, address = {New York and Basel},
 series		= {Lecture Notes in Pure and Applied Mathematics},
 number		= 195, pages = {109--131}, year = 1997,
 summary	= {Quasi-Newton trust-region methods for unconstrained and
		   bound-constrained optimization are proven to be robust
		   with respect to errors in the gradient. Global convergence
		   and active constraint identifications are proved under the
		   assumption that this error is bounded by a multiple of the
		   trust-region radius and that the model's Hessians are 
		   bounded and non-zero.}}

@techreport{Feng98,
 author         = {G. Feng},
 title          = {Trust-region method with simplicial decomposition for
                   linearly constrained problems}, 
 institution    = {Department of Applied Mathematics, Tongji University},
 address        = {Shanghai, China},
 number         = {December, 17}, year = 1998,
 abstract       = {For the nonlinear programming problems, in which the 
                   objective function is continuously differentiable,
                   pseudo-convex and the feasible set is a nonempty polyhedron,
                   we develop an algorithm of trust region method using 
                   simplicial decomposition. The algorithm solves a linearly
                   constrained problem in the subprogram and a master program
                   iteratively. The subprogram is a linear programming similar
                   to Frank-Wolfe linearization technique, but with a
                   restricted stepsize, and produces feasible points defining
                   simplices.  the produced simplices are only subsets of the
                   feasible region of the original programming.  The master
                   program is a trust region method on the produced simplex.
                   According to the ratio of the actual and predicted reduction
                   in the master program, we change the stepsize in the
                   subproblem adaptively per iteration. The resulting
                   algorithm is proved to be globally convergent.  The
                   advantage of the algorithm over the original trust region
                   method is that the feasible region under consideration of
                   the former is only a subset of the latter.  But the
                   algorithm must solve an additional linear programming
                   problem which is relatively simpler.},
 summary        = {A trust-region method is presented for the solution of
                   pseudoconvex optimization problems subject to linear
                   constraints. The method uses restricted simplicial
                   decomposition to produce successive simplices that are
                   included in the feasible domain and a trust-region method
                   is then employed to minimize the objective function on
                   those simplices. }}

@techreport{Feng99,
 author         = {G. Feng},
 title          = {Combination of trust region method and simplicial
                   decomposition for linearly constrained problems},
 institution    = {Department of Applied mathematics, Tongji University},
 address        = {Shanghai, China},
 number         = {March}, year = 1999,
 abstract       = {The algorithm given here incorporates the restricted
                   decomposition algorithm (RSD) into the trust-region method
                   (TR).  The global convergence is proved.  The advantage of
                   the presented algorithm over RSD is that the former is exact
                   and finite in every iteration.  In comparison with TR the
                   feasible set of the master problem in the presented
                   algorithm is only the subset of that in TR and has no
                   restriction on step.  Thus the former is much easier to
                   solve than the latter.},
 summary        = {A variant of the method developed in \citebb{Feng98} is
                   presented, where no restriction on the steplength is
                   imposed on the master problem.}}

@article{FerrPang97b,
 author		= {M. C. Ferris and J. S. Pang},
 title		= {Engineering and Economic Applications of Complementarity
		   Problems},
 journal	= SIREV,
 volume		= 39, number = 4, pages = {669--713}, year = 1997}

@techreport{FerrKanzMuns98,
 author		= {M. C. Ferris and C. Kanzow and T. S. Munson},
 title		= {Feasible Descent Algorithms for Mixed Complementarity
		   Problems},
 institution	= MADISON, address = MADISON-ADDRESS,
 type		= {Mathematical Programming Technical Report},
 number		= {MP-TR-98-04}, year = 1998}

@techreport{FerrZavr96,
 author		= {M. C. Ferris and S. K. Zavriev},
 title		= {The linear convergence of a successive linear programming
		   algorithm},
 institution	= MADISON, address = MADISON-ADDRESS,
 type		= {Mathematical Programming Technical Report},
 number		= {MP-TR-96-12}, year = 1996,
 abstract	= {We present a successive linear programming algorithm for
		   solving constrained nonlinear optimization problems. The
		   algorithm employs an Armijo procedure for updating a trust
		   region radius. We prove the linear convergence of the
		   method by relating the solutions of our subproblems to
		   standard trust region and gradient projection subproblems
		   and adapting an error bound analysis due to
		   \citebb{LuoTsen93}. Computational results are provided for
		   polyhedrally constrained nonlinear programs.},
 summary	= {A successive linear programming algorithm for solving
		   constrained nonlinear optimization problems is presented.
		   that usess an Armijo procedure for updating a
		   trust region radius. Linear convergence of the method is
		   proved by relating the solutions of the subproblems to
		   standard trust-region and gradient projection subproblems
		   and adapting an error bound analysis of
		   \citebb{LuoTsen93}. Computational results are provided for
		   polyhedrally constrained nonlinear programs.}}

@article{Fiac76,
 author		= {A. V. Fiacco},
 title		= {Sensitivity analysis for nonlinear programming using
		   penalty methods},
 journal	= MP,
 volume		= 10, number = 3, pages = {287--311}, year = 1976}

@book{Fiac83,
 author		= {A. V. Fiacco},
 title		= {Introduction to Sensitivity and Stability Analysis in
		   Nonlinear Programming},
 publisher	= AP, address = AP-ADDRESS,
 series		= {Mathematics in Science and Engineering}, volume = 165,
 year		= 1983}

@techreport{FiacMcCo63,
 author		= {A. V. Fiacco and G. P. McCormick},
 title		= {Programming under Nonlinear Constraints by Unconstrained
		   Optimization: a Primal-Dual Method},
 institution	= {Research Analysis Corporation},
 address	= {McLean, Virginia, USA},
 number		= {RAC-TP-96}, year = 1963}

@article{FiacMcCo64a,
 author		= {A. V. Fiacco and G. P. McCormick},
 title		= {The Sequential Unconstrained Minimization Technique for
		   Nonlinear Programming: a Primal-Dual Method},
 journal	= {Management Science},
 volume		= 10, number = 2, pages = {360--366}, year = 1964}

@article{FiacMcCo64b,
 author		= {A. V. Fiacco and G. P. McCormick},
 title		= {Computational Algorithm for the Sequential Unconstrained
		   Minimization Technique for Nonlinear Programming},
 journal	= {Management Science},
 volume		= 10, number = 4, pages = {601--617}, year = 1964}

@book{FiacMcCo68,
 author		= {A. V. Fiacco and G. P. McCormick},
 title		= {Nonlinear Programming: Sequential Unconstrained
		   Minimization Techniques},
 publisher	= WILEY, address = WILEY-ADDRESS,
 year		= 1968,
 note		= {Reprinted as \emph{Classics in Applied Mathematics 4}, SIAM,
		   Philadelphia, USA, 1990}}

@article{Fisc92,
 author		= {A. Fischer},
 title		= {A special {N}ewton-type optimization method},
 journal	= {Optimization},
 volume		= 24, number = {3--4}, pages = {269--284}, year = 1992}

@inproceedings{Fisc95,
 author		= {A. Fischer},
 title		= {An {NCP}-function and its use for the solution of
		   complementarity problems},
 crossref	= {DuQiWome95}, pages = {88--105}}

@article{Flet70,
 author		= {R. Fletcher},
 title		= {A New Approach to Variable Metric Algorithms},
 journal	= COMPJ,
 volume		= 13, pages = {317--322}, year = 1970}

@incollection{Flet70b,
 author		= {R. Fletcher},
 title		= {A class of methods for nonlinear programming with
		   termination and convergence properties},
 booktitle	= {Integer and nonlinear programming},
 editor		= {J. Abadie},
 publisher	= NH, address = NH-ADDRESS,
 pages		= {157--175}, year = 1970}

@techreport{Flet70c,
 author		= {R. Fletcher},
 title          = {An efficient, globally convergent, algorithm for
                   unconstrained and linearly constrained optimization
                   problems},
 institution    = HARWELL, address = HARWELL-ADDRESS,
 number         = {TP 431}, year = 1970,
 abstract       = {An algorithm for minimization of functions of many
                   variables, subject possibly to linear constraints on the
                   variables, is described.  In it a subproblem is solved in
                   which a quadratic approximation is made to the object
                   function and minimized over a region in which the
                   approximation is valid. A strategy for deciding when this
                   region should be expanded or contracted is given.  The
                   quadratic approximation involves estimating the hessian
                   of the object function by a matrix which is updated at
                   each iteration by a formula recently reported by
                   \citebb{Powe70a}.  This formula enables global convergence
                   of the algorithm to be proved.  Use of such an
                   approximation, as against using exact second derivatives,
                   also enables a reduction of about 60\%\ to be made in the
                   number of operations to solve the subproblem.  Numerical
                   evidence is reported showing that the algorithm is
                   efficient in the number of function evaluations required
                   to solve well known test problems.},
 summary        = {An algorithm is described for minimization of nonlinear
                   functions, subject possibly to linear constraints on the
                   variables.  At each iteration, a quasi-Newton (PSB)
                   quadratic approximation of the objective function is
                   minimized over a region in which the approximation is valid.
                   A strategy for deciding when this region should be expanded
                   or contracted is given.  Global convergence is proved and
                   numerical tests show that the algorithm is efficient
                   in the number of function evaluations.}}

@article{Flet71,
 author 	= {R. Fletcher},
 title  	= {A general quadratic programming algorithm},
 journal 	= JIMA,
 volume 	= 7, pages = {76--91}, year = 1971}

@techreport{Flet71b,
 author		= {R. Fletcher},
 title		= {A modified {M}arquardt subroutine for nonlinear
		   least-squares},
 institution	= HARWELL, address = HARWELL-ADDRESS,
 number		= {AERE-R 6799}, year = 1971,
 abstract	= {A Fortran subroutine is described for minimizing a sum of
		   squares of functions of many variables. Such problems arise
		   in nonlinear data fitting, and in the solution of nonlinear
		   algebraic equations. The subroutine is based on an
		   algorithm due to \citebb{Marq63}, but with modifications
		   which improve the performance of the method in certain
		   circumstances, yet which require negligible extra computer
		   time and storage.},
 summary	= {A Fortran subroutine is described for minimizing a sum of
		   squares of functions of many variables. Such problems arise
		   in nonlinear data fitting, and in the solution of nonlinear
		   algebraic equations. The subroutine is based on an
		   algorithm due to \citebb{Marq63}, but with modifications
		   which improve the performance of the method, yet which
		   require negligible extra computer time and storage.}}
 
@article{Flet73,
 author		= {R. Fletcher},
 title		= {An exact penalty function for nonlinear programming with
		   inequalities},
 journal	= MP,
 volume		= 5, number = 2, pages = {129--150}, year = 1973}

@article{Flet76,
 author		= {R. Fletcher},
 title		= {Factorizing symmetric indefinite matrices},
 journal	= LAA,
 volume		= 14, pages = {257--272}, year = 1976}

@book{Flet80,
 author		= {R. Fletcher},
 title		= {Practical Methods of Optimization: Unconstrained
		   Optimization},
 publisher	= WILEY, address = WILEY-ADDRESS,
 year		= 1980}

@book{Flet81,
 author		= {R. Fletcher},
 title		= {Practical Methods of Optimization: Constrained Optimization},
 publisher	= WILEY, address = WILEY-ADDRESS,
 year		= 1981}

@inproceedings{Flet82,
 author		= {R. Fletcher},
 title		= {Second-order corrections for non-differentiable
		   optimization},
 booktitle	= {Numerical Analysis, Proceedings Dundee 1981},
 editor		= {G. A. Watson},
 publisher	= SPRINGER, address = SPRINGER-ADDRESS,
 pages		= {85--114}, year = 1982,
 note		= {Lecture Notes in Mathematics 912}}

@article{Flet82b,
 author		= {R. Fletcher},
 title		= {A model algorithm for composite nondifferentiable
		   optimization problems},
 journal	= MPS,
 volume		= 17, pages = {67--76}, year = 1982,
 abstract	= {Composite functions $\phi(x)=f(x) + h(c(x))$, where $f$ and
		   $c$ are smooth and $h$ is convex, encompass many
		   nondifferentiable optimization problems of interest
		   including exact penalty functions in nonlinear programming,
		   nonlinear min-max problems, best nonlinear $L_1$, $L_2$ and
		   $L_\infty$ approximation and finding feasible points of
		   nonlinear inequalities. The idea is used of making a linear
		   approximation to $c(x)$ whilst including second order terms
		   in a quadratic approximation to $f(x)$. This is used to
		   determine a composite function $\psi$ which approximates
		   $\phi(x)$ and a basic algorithm is proposed in which $\psi$
		   is minimized on each iteration. If the technique of step
		   restriction (or trust region) is incorporated into the
		   algorithm, then it is shown that global convergence can be
		   proved. It is also described briefly how the above
		   approximations ensure that a second order rate of
		   convergence is achieved by the basic algorithm. },
 summary	= {Composite functions $\phi(x)=f(x) + h(c(x))$, where $f$ and
		   $c$ are smooth and $h$ is convex, encompass many
		   non-differentiable optimization problems of interest. Making
		   a linear approximation to $c(x)$ whilst including
		   second-order terms in a quadratic approximation to $f(x)$
		   is used to determine a composite function $\psi$ which
		   approximates $\phi(x)$ , and an algorithm is proposed in
		   which $\psi$ is minimized on each iteration. If the trust
		   region technique is incorporated into the algorithm, then
		   global convergence can be proved. It is also described how
		   the above approximations ensure that a second-order rate of
		   convergence is achieved.}}

@inproceedings{Flet85,
 author		= {R. Fletcher},
 title		= {An $\ell_1$ penalty method for nonlinear constraints},
 crossref	= {BoggByrdSchn85}, pages = {26--40}}

@book{Flet87,
 author		= {R. Fletcher},
 title		= {Practical Methods of Optimization},
 publisher	= WILEY, address = WILEY-ADDRESS,
 edition	= {second}, year = 1987}

@inproceedings{Flet87b,
 author		= {R. Fletcher},
 title		= {Recent developments in linear and quadratic programming},
 crossref	= {IserPowe87}, pages = {213--243}}

@article{Flet95,
 author		= {R. Fletcher},
 title		= {An Optimal Positive Definite Update for Sparse {H}essian
		   Matrices},
 journal	= SIOPT,
 volume		= 5, number = 1, pages = {192--217}, year = 1995}

@article{FletJack74,
 author		= {R. Fletcher and M. P. Jackson},
 title		= {Minimization of a quadratic function of many variables
		   subject only to lower and upper bounds},
 journal	= JIMA,
 volume		= 14, number = 2, pages = {159--174}, year = 1974}

@article{FletSain89,
 author		= {R. Fletcher and Sainz de la Maza, E.},
 title		= {Nonlinear programming and nonsmooth optimization by
		   successive linear programming},
 journal	= MP,
 volume		= 43, number = 3, pages = {235--256}, year = 1989,
 abstract	= {Methods are considered for solving nonlinear programming
		   problems using an exact $\ell_1$ penalty function. LP-like
		   subproblems incorporating a trust region constraint are
		   solved successively both to estimate the active set and to
		   provide a foundation for proving global convergence. In one
		   particular method, second-order information is represented
		   by approximating the reduced Hessian matrix, and
		   \citebb{ColeConn82b} steps are taken. A criterion for
		   accepting these steps is given which enables the
		   superlinear convergence properties of the Coleman-Conn
		   method to be retained whilst preserving global convergence
		   and avoiding the \citebb{Mara78} effect. The methods
		   generalize to solve a wide range of composite nonsmooth
		   optimization problems and the theory is presented in this
		   general setting. A range of numerical experiments on small
		   test problems is described.},
 summary	= {Methods are considered for solving nonlinear programming
		   problems using an exact $\ell_1$ penalty function. LP-like
		   subproblems incorporating a trust-region constraint are
		   solved successively both to estimate the active set and to
		   provide a foundation for proving global convergence. In one
		   particular method, second-order information is represented
		   by approximating the reduced Hessian matrix, and
		   \citebb{ColeConn82b} steps are taken. A criterion for
		   accepting these steps is given which enables the
		   superlinear convergence properties of the Coleman-Conn
		   method to be retained whilst preserving global convergence
		   and avoiding the \citebb{Mara78} effect. The methods
		   generalize to solve a wide range of composite non-smooth
		   optimization problems and the theory is presented in this
		   general setting. A range of numerical experiments on small
		   test problems is described.}}

@techreport{FletLeyf97,
 author		= {R. Fletcher and S. Leyffer},
 title		= {Nonlinear Programming without a penalty function},
 institution	= DUNDEE, address = DUNDEE-ADDRESS,
 type           = {Numerical Analysis Report}, number = {NA/171}, year = 1997,
 abstract	= {In this paper the solution of nonlinear programming
		   problems by a Sequential Quadratic Programming (SQP)
		   trust--region algorithm is considered. The aim of the
		   present work is to promote global convergence without the
		   need to use a penalty function. Instead, a new concept of a
		   ``filter'' is introduced which allows a step to be accepted
		   if it reduces either the objective function or the
		   constraint violation function. Numerical tests on a wide
		   range of test problems are very encouraging and the new
		   algorithm compares favourably with LANCELOT and an
		   implementation of S$l_1$QP.},
 summary	= {A Sequential Quadratic Programming (SQP) trust-region
		   algorithm for nonlinear programming is considered, which is
		   globally convergent without the need to use a penalty
		   function. Instead, the concept of a ``filter'' is
		   introduced which allows a step to be accepted if it reduces
		   either the objective function or the constraint violation
		   function. Numerical tests on a wide range of test problems
		   are very encouraging and the new algorithm compares
		   favourably with {\sf LANCELOT} and an implementation of
		   S$l_1$QP.}}

@techreport{FletLeyf98,
 author         = {R. Fletcher and S. Leyffer},
 title          = {User Manual for filter{SQP}},
 institution    = DUNDEE, address = DUNDEE-ADDRESS,
 type           = {Numerical Analysis Report}, number = {NA/181}, year = 1998}

@techreport{FletLeyfToin98,
 author		= {R. Fletcher and S. Leyffer and Ph. L. Toint},
 title		= {On the Global Convergence of an {SLP}-Filter Algorithm},
 institution	= FUNDP, address = FUNDP-ADDRESS,
 number		= {98/13}, year = 1998,
 abstract	= {A mechanism for proving global convergence in filter-type
		   methods for nonlinear programming is described. Such
		   methods are characterized by their use of the dominance
		   concept of multiobjective optimization, instead of a
		   penalty parameter whose adjustment can be problematic. The
		   main interest is to demonstrate how convergence for NLP can
		   be induced without forcing sufficient descent in a
		   penalty-type merit function. The proof technique is
		   presented in a fairly basic context, but the ideas involved
		   are likely to be more widely applicable. The technique
		   allows a wide range of specific algorithmic choices
		   associated with updating the trust-region radius and with
		   feasibility restoration.},
 summary	= {A mechanism for proving global convergence in filter-type
		   trust-region methods for nonlinear programming is
		   described. The main interest is to demonstrate how global
		   convergence can be induced without forcing sufficient
		   descent in a penalty-type merit function. The technique of
		   proof allows a wide range of specific algorithmic choices
		   associated with updating the trust-region radius and with
		   feasibility restoration.}}

@techreport{FletLeyfToin00,
 author		= {R. Fletcher and S. Leyffer and Ph. L. Toint},
 title		= {On the Global Convergence of an {SQP}-Filter Algorithm},
 institution	= FUNDP, address = FUNDP-ADDRESS,
 number		= {???}, year = 2000,
 abstract	= {A mechanism for proving global convergence in filter-type
		   methods for nonlinear programming is described. Such
		   methods are characterized by their use of the dominance
		   concept of multiobjective optimization, instead of a
		   penalty parameter whose adjustment can be problematic. The
		   main interest is to demonstrate how convergence for NLP can
		   be induced without forcing sufficient descent in a
		   penalty-type merit function. The proof technique is
		   presented in a fairly basic context, but the ideas involved
		   are likely to be more widely applicable. The technique
		   allows a wide range of specific algorithmic choices
		   associated with updating the trust-region radius and with
		   feasibility restoration.},
 summary	= {A mechanism for proving global convergence in filter-type
		   trust-region methods for nonlinear programming is
		   described. The main interest is to demonstrate how global
		   convergence can be induced without forcing sufficient
		   descent in a penalty-type merit function. The technique of
		   proof allows a wide range of specific algorithmic choices
		   associated with updating the trust-region radius and with
		   feasibility restoration.}}

@techreport{FletGoulLeyfToin99,
 author		= {R. Fletcher and N. I. M. Gould and
                   S. Leyffer and Ph. L. Toint},
 title		= {Global Convergence of Trust-Region {SQP}-Filter Algorithms
                   for Nonlinear Programming}, 
 institution	= FUNDP, address = FUNDP-ADDRESS,
 number		= {99/03}, year = 1999,
 abstract       = {Global convergence to first-order critical points is
                   proved for two trust-region SQP-filter algorithms of
                   the type introduced by \citebb{FletLeyf97}. The algorithms
                   allow for an approximate solution of the quadratic
                   subproblem and incorporate the safeguarding tests
                   described in \citebb{FletLeyfToin98}. The first algorithm
                   decomposes the step into its normal and tangential
                   components, while the second replaces this decomposition
                   by a stronger condition on the associated model decrease.},
 summary        = {Global convergence to first-order critical points is
                   proved for two trust-region SQP-filter algorithms of
                   the type introduced by \citebb{FletLeyf97}. The algorithms
                   allow for an approximate solution of the quadratic
                   subproblem and incorporate the safeguarding tests
                   described in \citebb{FletLeyfToin98}. The first algorithm
                   decomposes the step into its normal and tangential
                   components, while the second replaces this decomposition
                   by a stronger condition on the associated model decrease.}}

@article{FletWats80,
 author		= {R. Fletcher and G. A. Watson},
 title		= {First and second order conditions for a class of
		   nondifferentiable optimization problems},
 journal	= MP,
 volume		= 18, number = 3, pages = {291--307}, year = 1980}

@article{FlipJans96,
 author		= {O. E. Flippo and B. Jansen},
 title		= {Duality and Sensitivity in nonconvex quadratic Optimization
		   over an Ellipsoid},
 journal	= {European Journal of Operational Research},
 volume		= 94, number = 1, pages = {167--178}, year = 1996,
 abstract	= {In this paper, a duality framework is discussed for the
		   problem of optimizing a nonconvex quadratic function over
		   an ellipsoid. Additional insight is obtained from the
		   observation that this nonconvex problem is in a sense
		   equivalent to a convex problem of the same type, from which
		   known necessary and sufficient conditions for optimality
		   readily follow. Based on the duality results, some existing
		   solution procedures are interpreted as in fact solving the
		   dual. The duality relations are also shown to provide a
		   natural framework for sensitivity analysis.},
 summary	= {A duality framework for the problem of optimizing a
		   non-convex quadratic function over an ellipsoid is
		   described. Additional insight is obtained by observing that
		   this non-convex problem is in a sense equivalent to a convex
		   problem of the same type, from which known necessary and
		   sufficient conditions for optimality readily follow. Based
		   on the duality results, some existing solution procedures
		   are interpreted as in fact solving the dual. The duality
		   relations also provide a natural framework for
		   sensitivity analysis.}}

@article{Font90,
 author		= {R. Fontecilla},
 title		= {Inexact Secant Methods for Nonlinear Constrained
		   Optimization},
 journal	= SINUM,
 volume		= 27, number = 1, pages = {154--165}, year = 1990}

@article{FontSteiTapi87,
 author		= {R. Fontecilla and T. Steihaug and R. A. Tapia},
 title		= {A convergence theory for a class of quasi-{N}ewton methods
		   for constrained optimization},
 journal	= SINUM,
 volume		= 24, number = 5, pages = {1133--1151}, year = 1987}

@book{FortGlow82,
 author		= {M. Fortin and R. Glowinski},
 title		= {M\'ethodes de {L}agrangien Augment\'e},
 publisher	= {Dunod}, address = {Paris, France},
 number		= 9,
 series		= {M\'{e}thodes math\'{e}matiques de l'informatique},
 year		= 1982}

@phdthesis{Fort00,
 author         = {Ch. Fortin},
 title          = {A Survey of the Trust-Region Subproblem within a
                   Semidefinite Framework},
 school         = {University of Waterloo},
 address        = {Waterloo, Ontario, Canada},
 year           = 2000,
 abstract        ={Trust region subproblems arise within a class of
                   unconstrained methods called trust region methods. The
                   subproblems consist of minimizing a quadratic function
                   subject to a norm constraint.  This thesis is a survey of
                   different methods developed to find an approximate solution
                   to the subproblem.  We study the well-known method of
                   \citebb{MoreSore83} and two recent methods for large sparse
                   problems: the so-called Lanczos method of
                   \citebb{GoulLuciRomaToin99} and the \citebb{RendWolk97}
                   algorithm.  The common ground to explore these methods will
                   be semi-definite programming.  This approach has been used
                   by \citebb{RendWolk97} to explain their method and the
                   Mor\'{e}-Sorensen algorithm; we extend this work to the
                   Lanczos method.  The last chapter of this thesis is
                   dedicated to some improvements done to the Rendl-Wolkowicz
                   algorithm and the comparisons between the Lanczos method 
                   and the Rendl and Wolkowicz algorithm.  In particular, we
                   show some weakness of the Lanczos method and show that the
                   Rendl-Wolkowicz algorithm is more robust.},
 summary        = {A survey of different methods developed to find an
                   approximate solution to the trust-region subproblem is
                   presented.  The well-known method of \citebb{MoreSore83}
                   and two recent methods for large sparse problems, namely
                   the so-called Lanczos method of \citebb{GoulLuciRomaToin99}
                   and the \citebb{RendWolk97} algorithm, are studied.  The
                   common ground to explore these methods is semi-definite
                   programming.  This approach has been used by
                   \citebb{RendWolk97} to explain their method and the
                   Mor\'{e}-Sorensen algorithm; this work is extended to the
                   Lanczos method.  Some improvements to the Rendl-Wolkowicz
                   algorithm are also described and the Lanczos method and
                   the Rendl and Wolkowicz algorithm compared.  Some weakness
                   of the Lanczos method is discussed and the Rendl-Wolkowicz
                   algorithm is argued to be more robust.}}

@article{FourMehr93,
 author		= {R. Fourer and S. Mehrotra},
 title		= {Solving symmetrical indefinite systems for an
		   interior-point method for linear programming},
 journal	= MPA,
 volume		= 62, number = 1, pages = {15--39}, year = 1993}

@article{FoxHallSchr78,
 author		= {P. A. Fox and A. D. Hall and N. L. Schryer},
 title		= {The {PORT} mathematical subroutine library},
 journal	= TOMS,
 volume		= 4, number = 2, pages = {104--126}, year = 1978}

@techreport{Fral89,
 author		= {C. Fraley},
 title		= {Software Performance on Nonlinear Least-Squares Problems},
 institution	= STANFORD, address = STANFORD-ADDRESS,
 number		= {CS-TR-89-1244}, year = 1989,
 abstract	= {This paper presents numerical results for a large and
		   varied set of problems using software that is widely
		   available and has undergone extensive testing. The
		   algorithms implemented in this software include
		   Newton-based linesearch and trust-region methods for
		   unconstrained optimization, as well as Gauss-Newton,
		   Levenberg-Marquardt, and special quasi-Newton methods for
		   nonlinear least squares. Rather than give a critical
		   assessment of the software itself, our original purpose was
		   to use the best available software to compare the
		   underlying algorithms, to identify classes of problems for
		   each method on which the performance is either very good or
		   very poor and to provide benchmarks for future work in
		   nonlinear least squares and unconstrained optimization. The
		   variability in the results made it impossible to meet
		   either of the first two goals; however the results are
		   significant as a step toward explaining why these aims are
		   so difficult to accomplish.},
 summary	= {Numerical results are presented for a large set of problems
		   using software that is widely available and has undergone
		   extensive testing. The algorithms implemented include
		   Newton-based linesearch and trust-region methods for
		   unconstrained optimization, as well as Gauss-Newton,
		   Levenberg-Morrison-Marquardt, and special quasi-Newton
		   methods for nonlinear least-squares. Rather than give a
		   critical assessment of the software itself, the original
		   intention was to use the best available software to compare
		   the underlying algorithms, to identify classes of problems
		   for each method on which the performance is either very
		   good or very poor and to provide benchmarks for future work
		   in nonlinear least-squares and unconstrained optimization.
		   The variability in the results makes it impossible to meet
		   either of the first two goals; however the results are
		   significant as a step toward explaining why these aims are
		   so difficult to accomplish.}}

@article{FranWolf56,
 author		= {M. Frank and P. Wolfe},
 title  	= {An algorithm for quadratic programming},
 journal 	= {Naval Research Logistics Quarterly},
 volume 	= 3, pages = {95--110}, year = 1956}

@article{Freu91,
 author		= {R. M. Freund},
 title		= {Theoretical efficiency of a shifted-barrier-function
		   algorithm for linear programming},
 journal	= LAA,
 volume		= 152, pages = {19--41}, year = 1991}

@article{FrieMart94,
 author		= {A. Friedlander and J. M. Mart\'{\i}nez},
 title		= {On the Maximization of a Concave Quadratic Function with
		   Box Constraints},
 journal	= SIOPT,
 volume		= 4, number = 1, pages = {177--192}, year = 1994}

@article{FrieMartRayd95,
 author		= {A. Friedlander and J. M. Mart\'{\i}nez and M. Raydan},
 title		= {A new method for large-scale box constrained convex
		   quadratic minimization problems},
 journal	= OMS,
 volume		= 5, number = 1, pages = {57--74}, year = 1995}

@article{FrieMartSant94,
 author		= {A. Friedlander and J. M. Mart\'{\i}nez and S. A. Santos},
 title		= {A new Trust Region Algorithm for Bound Constrained
		   Minimization},
 journal	= {Applied Mathematics and Optimization},
 volume		= 30, number = 3, pages = {235--266}, year = 1994,
 abstract	= {A new method for maximizing a concave quadratic function
		   with bounds on the variables is described. The new
		   algorithm combines conjugate gradients with gradient
		   projection techniques, as the algorithm of
		   \citebb{MoreTora91} and other well-known method do. A new
		   strategy for the decision of leaving the current face is
		   introduced that makes it possible to obtain finite
		   convergence even for a singular Hessian and in the presence
		   of dual degeneracy. Numerical experiments are presented.},
 summary	= {A method for maximizing a concave quadratic function with
		   bounds on the variables is described, which combines
		   conjugate gradients with gradient projection techniques, as
		   in \citebb{MoreTora91}. A strategy for the decision of
		   leaving the current face is introduced that ensures finite
		   convergence even for a singular Hessian and in the presence
		   of dual degeneracy. Numerical experiments are presented.}}

@article{FrieMartSant94b,
 author		= {A. Friedlander and J. M. Mart\'{\i}nez and S. A. Santos},
 title		= {On the resolution of linearly constrained convex
		   minimization problems},
 journal	= SIOPT,
 volume		= 4, number = 2, pages = {331--339}, year = 1994,
 abstract	= {The problem of minimizing a twice continuously
		   differentiable convex function $f$ is considered, subject
		   to $Ax=b$, $x \geq 0$, where $A \in \Re^{m \times n}$, $m$,
		   $n$ are large and the feasible region is bounded. It is
		   proven that this problem is equivalent to a ``primal-dual''
		   box-constrained problem with $2n+m$ variables. This problem
		   is solved using an algorithm for bound constrained
		   minimization that can deal with many variables. Numerical
		   experiments are presented.},
 summary	= {The problem of minimizing a twice continuously
		   differentiable convex function $f$ is considered, subject
		   to $Ax=b$, $x \geq 0$, where $A \in \Re^{m \times n}$, $m$,
		   $n$ are large and the feasible region is bounded. It is
		   proven that this problem is equivalent to a ``primal-dual''
		   box-constrained problem with $2n+m$ variables. This problem
		   is solved using an algorithm for bound constrained
		   minimization that can deal with many variables. Numerical
		   experiments are presented.}}

@techreport{Fris54,
 author		= {K. R. Frisch},
 title		= {Principles of Linear Programming---With Particular
		   Reference to the Double Gradient Form of the Logarithmic
		   Potential Method},
 institution	= {University Institute for Economics}, address = {Oslo},
 type		= {Memorandum of October 18}, year = 1954}

@techreport{Fris55,
 author		= {K. R. Frisch},
 title		= {The Logarithmic Potential Function for Convex Programming},
 institution	= {University Institute for Economics}, address = {Oslo},
 type		= {Memorandum of May 13}, year = 1955}

@mastersthesis{Fugg96,
 author		= {P. Fugger},
 title		= {Trust region subproblems and comparison with quasi-{N}ewton
		   methods},
 school		= {Technical University of Graz}, address = {Graz, Austria},
 year		= 1996,
 abstract	= {In the field of unconstrained nonlinear optimization
		   Quasi-Newton methods (e.g. the DFP and BFGS formulae) are
		   well-known and extensively studied in the literature.
		   Another approach to the minimization of nonlinear problems
		   is done by the so-called restricted step or trust region
		   methods. One possibility for solving the Trust Region
		   subproblem (TRS) is to apply a parametric eigenvalue
		   problem (Rendl's method). The choice of the parameter of
		   Rendl's method is decisive for the number of iterations
		   needed to obtain a minimizer. The computational amount of
		   the method is compared with the costs of the DFP algorithm},
 summary	= {One possibility for solving the trust-region subproblem is
		   to apply a parametric eigenvalue problem (Rendl's method).
		   The choice of the parameter of Rendl's method is decisive
		   for the number of iterations needed to obtain a minimizer.
		   The computational efficiency of this method is compared
		   with that of the DFP algorithm}}

@article{FujiKojiNaka97,
 author		= {K. Fujisawa and M. Kojima and K. Nakata},
 title		= {Exploiting sparsity in primal-dual interior-point methods
		   for semidefinite programming},
 journal	= MPB,
 volume		= 79, number = {1--3}, pages = {235--253}, year = 1997}

@article{Fuku86b,
 author		= {M. Fukushima},
 title		= {A successive quadratic-programming algorithm with global
		   and superlinear convergence properties},
 journal	= MP,
 volume		= 35, number = 3, pages = {253--264}, year = 1986}

@article{Fuku92,
 author		= {M. Fukushima},
 title		= {Equivalent differentiable optimization problems and descent
		   methods for asymmetric variational inequality problems},
 journal	= MPA,
 volume		= 53, number = 1, pages = {99--110}, year = 1992}

@inproceedings{Fuku96,
 author		= {M. Fukushima},
 title		= {Merit functions for variational inequality and
		   complementarity problems},
 crossref	= {DiPiGian96}, pages = {155--170}}

@article{FukuHaddvanStroSugiYama96,
 author         = {M. Fukushima and M. Haddou and Nguyen, H. v. and 
                   J. J. Strodiot and T. Sugimoto and E. Yamakawa},
 title          = {A parallel descent algorithm for convex programming},
 journal        = COAP,
 volume         = 5, number = 1, pages = {5--37}, year = 1996,
 abstract       = {In this paper, we propose a parallel decomposition
                   algorithm for solving a class of convex optimization
                   problems, which is broad enough to contain ordinary
                   convex programming problems with a strongly convex
                   objective function. The algorithm is a variant of the
                   trust region method applied to the Fenchel dual of
                   the given problem. We prove global convergence of the
                   algorithm and report some computational experience
                   with the proposed algorithm on the Connection Machine
                   Model CM-5.},
 summary        = {A parallel decomposition algorithm for solving a class
		   of convex optimization problem is proposed that contains
		   convex programming problems with a strongly convex
		   objective function. The algorithm is a variant of the
		   trust-region method applied to the Fenchel dual of the
		   problem. We prove global convergence and report
		   computational experience on the Connection Machine Model
		   CM-5.}} 


@article{FukuYama86,
 author         = {M. Fukushima and Y. Yamamoto},
 title          = {A second-order algorithm for continuous-time nonlinear 
                   optimal control problems},
 journal        = {IEEE Transactions on Automatic Control},
 volume         = {AC-31}, number = 7, pages = {673--676}, year = 1986,
 abstract       = {A second-order algorithm is presented for the
                   solution of continuous-time nonlinear optimal control
                   problems. The algorithm is an adaptation of the trust
                   region modifications of Newton's method and solves at
                   each iteration a linear-quadratic control problem
                   with an additional constraint. Under some
                   assumptions, the proposed algorithm is shown to
                   possess a global convergence property. A numerical
                   example illustrates the method.},
 summary        = {A second-order algorithm is presented for the
                   solution of continuous-time nonlinear optimal control
                   problems. The algorithm is a trust-region variant of
		   Newton's method and solves at each iteration a
		   linear-quadratic control problem with an additional
		   constraint. The algorithm is globally convergent. A
		   numerical example illustrates the method.}}


@techreport{FuLuoYe96,
 author		= {M. Fu and Z. Q. Luo and Y. Ye},
 title		= {Approximation algorithms for quadratic programming},
 institution	= {Department of Management Science, University of Iowa},
 year		= 1996,
 abstract	= {We consider the problem of approximating the global minimum
		   of a general quadratic program (QP) with $n$ variables
		   subject to $m$ ellipsoidal constraints. For $m=1$, we
		   rigorously show that and $\epsilon$-minimizer, where error
		   $\epsilon \in (0,1)$, can be obtained in polynomial time,
		   meaning that the number of arithmetic operations is a
		   polynomial in $n$, $m$ and $\log(1/\epsilon)$. For $m \geq
		   2$, we present a polynomial-time $(1-
		   \frac{1}{m^2})$-approximation algorithm as well as a
		   semidefinite programming relaxation for this problem. In
		   addition, we present approximation algorithms for solving
		   QP under the box constraints and the assignment polytope
		   constraints.},
 summary	= {The problem of approximating the global minimum of a
		   general quadratic program (QP) with $n$ variables subject
		   to $m$ ellipsoidal constraints is considered. For $m=1$, it
		   is shown that and $\epsilon$-minimizer, where error
		   $\epsilon \in (0,1)$, can be obtained in polynomial time,
		   meaning that the number of arithmetic operations is a
		   polynomial in $n$, $m$ and $\log(1/\epsilon)$. For $m \geq
		   2$, a polynomial-time $(1- \frac{1}{m^2})$-approximation
		   algorithm is presented, as well as a semidefinite
		   programming relaxation for this problem. In addition,
		   approximation algorithms for solving QP under the box
		   constraints and the assignment polytope constraints are
		   given.}}

@article{Fure93,
 author         = {B. P. Furey},
 title          = {A sequential quadratic programming-based algorithm for 
                   optimization of gas networks},
 journal        = {Automatica},
 volume         = 29, number = 6, pages = {1439-1450}, year = 1993,
 abstract       = {British Gas uses a complex, heavily looped network of
                   pipes and controllable units (compressors and
                   regulators) to transmit gas from coastal supply
                   terminals to regional demand points. Computer
                   algorithms are required for efficient management of
                   the system. This paper describes an algorithm for
                   optimal control over periods of up to a day. The
                   problem is large scale and highly nonlinear in both
                   objective function and constraints. The method is
                   based on sequential quadratic programming and takes
                   account of the structure of the pipeflow equations by
                   means of a reduced gradient technique which
                   eliminates most of the variables from the quadratic
                   subproblems. The latter involve only simple bound
                   constraints, which are handled efficiently by a
                   conjugate gradient-active set algorithm. Trust region
                   techniques permit use of the exact Hessian,
                   preserving sparsity. More general constraints are
                   handled at an outer level by a truncated augmented
                   Lagrangian method. Results are included for some
                   realistic problems. The algorithm is generally
                   applicable to problems with a control structure.},
 summary        = {An algorithm for optimal control of the British Gas
		   network of pipes and controllable units over periods
		   of up to a day is described. The
                   problem is large-scale and highly nonlinear in both
                   objective function and constraints. The method is
                   based on sequential quadratic programming and takes
                   account of the structure of the pipeflow equations by
                   means of a reduced gradient technique. which
                   eliminates most of the variables from the quadratic
                   subproblems. The latter involve only simple bound
                   constraints, which are handled efficiently by a
                   conjugate gradient-active set algorithm. Trust-region
                   techniques permit use of the exact Hessian,
                   preserving sparsity. More general constraints are
                   handled at an outer level by a truncated augmented
                   Lagrangian method. Results are included for some
                   realistic problems.}}


%%% G %%%

@techreport{GabrMore95,
 author		= {S. A. Gabriel and J. J. Mor\'{e}},
 title		= {Smoothing of mixed complementarity problems},
 institution	= ANL, address = ANL-ADDRESS,
 number		= {MCS-P541-00995}, year = 1995}

@inproceedings{GabrPang94,
 author		= {S. A. Gabriel and J. S. Pang},
 title		= {A trust region method for constrained nonsmooth equations},
 crossref	= {HageHearPard94}, pages = {155--181},
 abstract	= {In this paper, we develop and analyze the convergence of a
		   fairly general trust region method for solving a system of
		   nonsmooth equations subject to some linear constraints. The
		   method is based on the existence of an iteration function
		   for the nonsmooth equations and involves the solution of a
		   sequence of subproblems defined by this function. A
		   particular realization of the method leads to an
		   arbitrary-norm trust region method. Applications of the
		   latter method to the nonlinear complementarity and related
		   problems are discussed. Sequential convergence of the
		   method and its rate of convergence are established under
		   certain regularity conditions similar to those used in the
		   NE/SQP method and its generalization. Some computational
		   results are reported.},
 summary	= {The convergence of a trust-region method for solving a
		   system of non-smooth equations subject to linear
		   constraints is considered. The method is based on the
		   existence of an iteration function for the non-smooth
		   equations and involves the solution of a sequence of
		   subproblems defined by this function. A particular
		   realization of the method leads to an arbitrary-norm
		   trust-region method. Applications of the latter method to
		   the nonlinear complementarity and related problems are
		   discussed. Global convergence of the method and its rate of
		   convergence are established under certain regularity
		   conditions similar to those used in the NE/SQP method and
		   its generalization. Computational results are reported.}}

@phdthesis{Gand78,
 author         = {W. Gander},
 title          = {On the linear least squares problem with a quadratic
                   constraint},
 school         = {Computer Science Department, Stanford University},
 address        = {Stanford, California, USA},
 number         = {STAN-CS-78-697}, year = 1978}

@article{Gand81,
 author  	= {W. Gander},
 title  	= {Least squares with a quadratic constraint},
 journal 	= NUMMATH,
 volume  	= 36, pages = {291--307}, year = 1981,
 abstract       = {We present the theory of the linear least squares problem
                   with a quadratic constraint.  New theorems characterizing
                   properties of the solutions are given.  A numerical
                   application is discussed.},
 summary        = {Properties of the solutions of the linear least-squares
                   problem with a quadratic constraint are given and a
                   numerical applcation discussed. The paper summarizes
                   \citebb{Gand78}}}

@inproceedings{Gao98,
 author		= {L. Gao},
 title		= {Using {H}uber Method to solve $L_1$-norm problem},
 crossref	= {Yuan98}, pages = {263--272},
 abstract	= {The nondifferentiable $L_1$ function is approximated by the
		   Huber function, such that the original $L_1$ estimation
		   problem is transformed to a sequence of unconstrained
		   minimization problems. An algorithm is consider for the
		   Huber problem. Numerical experiments are reported and
		   comparisons within different methods are made},
 summary	= {The non-differentiable $\ell_1$ estimation problem is
		   replaced by a sequence of smooth minimization problems
		   using the Huber function to approximate the absolute value.
		   An algorithm is proposed that uses a trust-region method
		   to solve each of the subproblems. Numerical comparisons are
		   made with competing approaches.}}

@book{GareJohn79,
 author		= {M. R. Garey and D. S. Johnson},
 title		= {Computers and Intractibility},
 publisher	= FREEMAN, address = FREEMAN-ADDRESS,
 year		= 1979}

@article{Garf90,
 author		= {E. Garfield},
 title		= {The most cited papers of all time, {SCI} 1945--1988. 
                   {P}art 3.
		   {A}nother 100 from the Citation Classics Hall of Fame},
 journal	= {Current Contents},
 volume		= 34, pages = {3--13}, year = 1990}

@article{Gay81,
 author		= {D. M. Gay},
 title		= {Computing optimal locally constrained steps},
 journal	= SISSC,
 volume		= 2, pages = {186--197}, year = 1981,
 abstract	= {In seeking to solve an unconstrained minimization problem,
		   one often computes steps based on a quadratic approximation
		   $q$ to the objective function. A reasonable way to choose
		   such steps is by minimizing $q$ constrained to a
		   neighbourhood of the current iterate. This paper considers
		   ellipsoidal neighbourhoods and presents a new way to handle
		   certain computational details when the Hessian of $q$ is
		   indefinite, paying particular attention to a special case
		   which may then arise. The proposed step computing algorithm
		   provides an attractive way to deal with negative curvature.
		   Implementations of this algorithm have proved very
		   satisfactory in the nonlinear least-squares solver NL2SOL.},
 summary	= {The solution of the trust-region subproblem with
		   ellipsoidal norms is considered and a way to handle
		   certain computational details when the Hessian of $q$ is
		   indefinite is presented, paying particular attention to the
		   hard case. The proposed step computing algorithm provides
		   an attractive way to deal with negative curvature.
		   Implementations of the algorithm have proved very
		   satisfactory in the nonlinear least-squares solver NL2SOL.}}

@techreport{Gay82,
 author		= {D. M. Gay},
 title		= {On the convergence in Model/Trust-Region Algorithms for
		   Unconstrained Optimization},
 institution	= BELLLABS,  address = BELLLABS-ADDRESS,
 type		= {Computing Science Technical Report}, number = 104,
 year		= 1982,
 abstract	= {This paper discusses convergence tests in the context of
		   model/trust-region algorithms for solving unconstrained
		   optimization problems. It presents a general theorem that
		   supports a diagnostic test for possible convergence to a
		   minimizer at which the Hessian of the objective function is
		   singular. (This is an event with which one must be prepared
		   to deal in problems that arise from fitting a mathematical
		   model to data.) Given just continuity of the objective
		   function's gradient, the theorem assures that either the
		   ``singular convergence'' test is satisfied infinitely often
		   for any positive convergence tolerance, or else the lengths
		   of the steps taken tend to zero; moreover, if the model
		   Hessians are locally bounded, then any limit point of the
		   iterates is a critical point. One can use this information
		   in a suite of convergence tests that in my opinion involve
		   easily understood tolerances and provide helpful
		   diagnostics.},
 summary	= {Convergence tests in the context of model/trust-region
		   algorithms for solving unconstrained optimization problems
		   are discussed. A general theorem that supports a diagnostic
		   test for possible convergence to a minimizer at which the
		   Hessian of the objective function is singular is given. If
		   the gradient of the objective function is continuous, the
		   theorem assures that either the ``singular convergence''
		   test is satisfied infinitely often for any positive
		   convergence tolerance, or else the lengths of the steps
		   taken tend to zero; moreover, if the model Hessians are
		   locally bounded, then any limit point of the iterates is a
		   critical point. This information can be used in a suite of
		   convergence tests that involve easily understood tolerances
		   and which provide helpful diagnostics.}}

@article{Gay83b,
 author		= {D. M. Gay},
 title		= {Algorithm 611: subroutines for unconstrained minimization
		   using a model/trust-region approach},
 journal	= TOMS,
 volume		= 9, number = 4, pages = {503--524}, year = 1983,
 summary	= {A set of subroutines for the minimization of a smooth
		   function are provided.  These codes work with exact or
		   finite-difference gradients, and exact or secant
		   approximations to Hessians, using the reverse-communication
		   paradigm.  An approximation to the trust-region subproblem
		   is computed using the double-dogleg technique of 
		   \citebb{DennMei79}.}}

@inproceedings{Gay84,
 author		= {D. M. Gay},
 title		= {A trust region approach to linearly constrained
		   optimization},
 booktitle	= {Numerical Analysis: Proceedings Dundee 1983},
 editor		= {D. F. Griffiths},
 publisher	= SPRINGER, address = SPRINGER-ADDRESS,
 pages		= {72--105}, year = 1984,
 note		= {Lecture Notes in Mathematics 1066},
 abstract	= {This paper suggests a class of trust-region algorithms for
		   solving linearly constrained optimization problems. The
		   algorithms use a ``local'' active-set strategy to select
		   the steps they try. This strategy is such that degeneracy
		   and zero Lagrange multipliers do not slow convergence (to a
		   first-order stationary point) and that no anti-zigzagging
		   precautions are necessary. (Unfortunately, when there are
		   zero Lagrange multipliers, convergence to a point failing
		   to satisfy second-order necessary conditions remains
		   possible.) We discuss specialization of the algorithms to
		   the case of simple bounds on the variables and report
		   preliminary computational experience.},
 summary	= {A class of trust-region algorithms for solving linearly
		   constrained optimization problems is suggested. The
		   algorithms use a ``local'' active-set strategy to select
		   their steps. This strategy is such that degeneracy and zero
		   Lagrange multipliers do not slow convergence (to a
		   first-order stationary point) and that no anti-zigzagging
		   precautions are necessary---when there are zero Lagrange
		   multipliers, convergence to a point failing to satisfy
		   second-order necessary conditions remains possible.
		   Specialization of the algorithms to the case of simple
		   bounds on the variables are discussed, and preliminary
		   computational experience reported.}}

@inproceedings{GayOverWrig98,
 author		= {D. M. Gay and M. L. Overton and M. H. Wright},
 title		= {A Primal-Dual Interior Method for Nonconvex Nonlinear
		   Programming},
 crossref	= {Yuan98}, pages = {31--56}}

@article{GermToin99,
 author         = {M. Germain and Ph. L. Toint},
 title          = {An Iterative Process for International Negotiations
                   on Acid Rain in Northern Europe Using a General Convex
                   Formulations},
 journal        = {Environmental and Resource Economics},
 note           = {To appear.}, year = 1999,
 abstract       = {This paper proposes a game theoretical approach of
		   international negotiations on transboundary pollution. 
		   This approach is distinguished by a discrete time
		   formulation and by a suitable formulation of the local
		   information assumption on cost and damage functions: at
		   each stage of the negotiation, the parties assign the best
		   possible cooperative state, given the available information,
		   as an objective for the next stage.  It is shown that the
		   resulting sequences of states converges from a
		   non-cooperative situation to an international optimum in a
		   finite number of stages.  Furthermore, a financial transfer
		   structure is also presented that makes the desired sequence 
		   of states individually rational and strategically stable. 
		   The concepts are applied in a numerical simulation of the 
		   $SO_2$ transboundary pollution problem related to
		   acid rain in Northern Europe.},
 summary	= {A game theoretical approach of international negotiations
		   on transboundary pollution is proposed, that uses
		   a discrete time formulation. The resulting sequences of
		   states is shown to converge from a non-cooperative
		   situation to an international optimum in a finite number 
		   of stages.  A financial transfer structure is also presented
		   that makes the desired sequence of states individually
		   rational and strategically stable. The concepts are applied
		   in a numerical simulation of the  $SO_2$ transboundary 
		   pollution problem related to acid rain in Northern Europe,
		   using a trust-region method to calculate the optimum at
		   each negotiation stage.}}

@article{GeorLiu79,
 author		= {A. George and J. W. H. Liu},
 title		= {The design of a user interface for a sparse matrix package},
 journal	= TOMS,
 volume		= 5, number = 2, pages = {139--162}, year = 1979}

@book{GeorLiu81,
 author		= {A. George and J. W. H. Liu},
 title		= {Computer Solution of Large Sparse Positive Definite Systems},
 publisher	= PH, address = PH-ADDRESS,
 year		= 1981}

@phdthesis{Gert99,
 author         = {E. M. Gertz},
 title          = {Combination Trust-Region Line-Search Methods for 
                   Unconstrained Optimization},
 school         = {Department of Mathematics, University of California},
 address        = {San Diego, California, USA},
 year           = 1999,
 abstract       = {Many important problems may be expressed in terms of
                   nonlinear multivariate unconstrained optimization.  The 
                   basic unconstrained optimization problem is to minimize a
                   real-valued function $f(x)$ over all vectors $x \in \Re^n$.
                   Many techniques for solving these types of problems are
                   available if $f$ is twice continuously differentiable.  
                   Two broad classes of algorithms for the unconstrained
                   minimization problem are trst-region algorithms and 
                   line-search algorithms.  These two classes may be combined
                   by performing a line search in the direction proposed by the
                   solution to the trust-region subproblem.  We develop three
                   combination methods which require that a sufficient
                   decrease condition is met at each step.  The first of the
                   new algorithms uses a backtracking line search based on the
                   Armijo condition.  In all these algorithms the line search
                   is used to control the trust-region radius.  We present
                   strong first and second order convergence theorems for
                   these new methods, an analysis of their asymptotic
                   convergence properties and the results of numerical
                   experiments using the new algorithms. It is possible to
                   use the Wolfe-condition based algorithms to define
                   quasi-Newton methods which use the BFGS update.  The
                   quasi-Newton methods are robust and efficient.},
 summary        = {Three unconstrained minimization methods are presented that
                   combine trust-region and linesearch techniques, in the
                   sense that a linesearch is performed in the direction
                   obtained from the solution of the trust-region subproblem.
                   The linesearch is also used to control the trust-region 
                   radius. Strong global convergence to first- and second-order
                   points is proved and the asymptotic convergence properties
                   of the algorithms analyzed. Numerical results are presented,
                   that include a quasi-Newton BFGS variant of the algorithms.}}

@article{Gilb91,
 author		= {J. Ch. Gilbert},
 title		= {Maintaining the positive definiteness of the matrices in
		   reduced secant methods for equality constrained
		   optimization},
 journal	= MP,
 volume		= 50, number = 1, pages = {1--28}, year = 1991}

@article{GillGoulMurrSaunWrig84,
 author 	= {P. E. Gill and N. I. M. Gould and W. Murray
		   and M. A. Saunders and M. H. Wright},
 title  	= {A weighted {G}ram-{S}chmidt method for convex 
           	   quadratic programming},
 journal 	= MP,
 volume 	= 30, number = 2, pages = {176--195}, year = 1984}

@article{GillMurr74,
 author		= {P. E. Gill and W. Murray},
 title		= {{N}ewton-type methods for unconstrained and linearly
		   constrained optimization},
 journal	= MP,
 volume		= 7, number = 3, pages = {311--350}, year = 1974}

@techreport{GillMurr76,
 author		= {P. E. Gill and W. Murray},
 title		= {Minimization subject to bounds on the variables},
 institution	= NPL, address = NPL-ADDRESS,
 type		= {NPL Report}, number = {NAC 72}, year = 1976}

@article{GillMurr78,
 author 	= {P. E. Gill and W. Murray},
 title  	= {Numerically stable methods for quadratic programming},
 journal 	= MP,
 volume 	= 14, number = 3, pages = {349--372}, year = 1978}

@article{GillMurrPoncSaun92,
 author		= {P. E. Gill and W. Murray and D. B. Poncele\'{o}n and M. A.
		   Saunders},
 title		= {Preconditioners for indefinite systems arising in
		   optimization},
 journal	= SIMAA,
 volume		= 13, number = 1, pages = {292--311}, year = 1992}

@article{GillMurrSaunWrig83, 
 author 	= {P. E. Gill and W. Murray and M. A. Saunders 
		   and M. H. Wright},
 title  	= {Computing forward-difference intervals for numerical
		   optimization},
 journal 	= SISSC,
 volume 	= 4, number = 2, pages = {310-321}, year = 1983}

@article{GillMurrSaunWrig85, 
 author 	= {P. E. Gill and W. Murray and M. A. Saunders 
		   and M. H. Wright},
 title          = {Some issues in implementing a sequential quadratic 
                   programming algorithm}, 
 journal        = {SIGNUM Newsletter},
 volume         = 20, number = 2, pages = {13--19}, year = 1985}

@article{GillMurrSaunStewWrig85,
 author		= {P. E. Gill and W. Murray and M. A. Saunders and G. W.
		   Stewart and M. H. Wright},
 title		= {Properties of a representation of a basis for the null
		   space},
 journal	= MP,
 volume		= 33, number = 2, pages = {172--186}, year = 1985}

@article{GillMurrSaunTomlWrig86,
 author		= {P. E. Gill and W. Murray and M. A. Saunders and J. A.
		   Tomlin and M. H. Wright},
 title		= {On projected {N}ewton barrier methods for linear
		   programming and an equivalence to {K}armarkar's projective
		   method},
 journal	= MP,
 volume		= 36, number = 2, pages = {183--209}, year = 1986}

@techreport{GillMurrSaunWrig88,
 author		= {P. E. Gill and W. Murray and M. A. Saunders and M. H.
		   Wright},
 title		= {Shifted barrier methods for linear programming},
 institution	= STANFORD, address = STANFORD-ADDRESS,
 type		= {Technical Report}, number = {SOL88-9}, year = 1988}

@inproceedings{GillMurrSaunWrig90,
 author 	= {P. E. Gill and W. Murray and M. A. Saunders
		   and M. H. Wright},
 title  	= {A {S}chur-complement method for sparse
		   quadratic programming},
 crossref 	= {CoxHamm90}, pages  = {113--138}}

@article{GillMurrSaunWrig91,
 author 	= {P. E. Gill and W. Murray and M. A. Saunders 
		   and M. H. Wright},
 title  	= {Inertia-controlling methods for general quadratic
		   programming},
 journal 	= SIREV,
 volume 	= 33, number = 1, pages = {1--36}, year = 1991}

@inproceedings{GillMurrSaunWrig92,
 author		= {P. E. Gill and W. Murray and M. A. Saunders and M. H.
		   Wright},
 title		= {Some theoretical properties of an augmented {L}agrangian
		   merit function},
 booktitle	= {Advances in Optimizations and Parallel Computing},
 editor		= {P. M. Pardalos},
 publisher	= {Elsevier}, address = {Amsterdam},
 pages		= {127--143}, year = 1992}

@book{GillMurrWrig81,
 author		= {P. E. Gill and W. Murray and M. H. Wright},
 title		= {Practical Optimization},
 publisher	= AP, address = AP-ADDRESS,
 year		= 1981}

@article{GladPola79,
 author		= {T. Glad and E. Polak},
 title		= {A multiplier method with automatic limitation of penalty
		   growth},
 journal	= MP,
 volume		= 17, number = 2, pages = {140--155}, year = 1979}

@article{Goem97,
 author		= {M. X. Goemans},
 title		= {Semidefinite programming in combinatorial optimization},
 journal	= MPB,
 volume		= 79, number = {1--3}, pages = {143--161}, year = 1997}

@article{Gold70,
 author		= {D. Goldfarb},
 title		= {A Family of Variable Metric Methods Derived by Variational
		   Means},
 journal	= MC,
 volume		= 24, pages = {23--26}, year = 1970}

@techreport{Gold80,
 author		= {D. Goldfarb},
 title		= {The Use of Negative Curvature in Minimization Algorithms},
 institution	= CS-CORNELL, address = CORNELL-ADDRESS,
 number		= {TR80-412}, year = 1980,
 abstract	= {In this paper we examine existing algorithms for
		   minimizing a nonlinear function of many variables which
		   make use of negative curvature. These algorithms can all be
		   viewed as modified versions of Newton's method and their
		   merits and drawbacks are discussed to help identify new and
		   more promising methods. The algorithms considered include
		   ones which compute and search along nonascent directions of
		   negative curvature and ones which search along curvi-linear
		   paths generated by these directions and descent directions.
		   Versions of the \citebb{GoldQuanTrot66}, or equivalently,
		   methods based upon a trust region strategy, and gradient
		   path methods are also considered. When combined with the
		   numerically stable \citebb{BuncParl71} factorization of a
		   symmetric indefinite matrix the latter two approaches give
		   rise to new, and what appears to be, efficient and robust
		   minimization methods which can take advantage of negative
		   curvature when it is encountered. Several suggestions are
		   made for further research in this area.},
 summary	= {Algorithms for minimizing a nonlinear function of many
		   variables which make use of negative curvature are
		   examined. These algorithms can all be viewed as modified
		   versions of Newton's method and their merits and drawbacks
		   are discussed to help identify new and more promising
		   methods. The algorithms considered include ones which
		   compute and search along non-ascent directions of negative
		   curvature and ones which search along curvilinear paths
		   generated by these directions and descent directions.
		   Versions of the \citebb{GoldQuanTrot66}, or equivalently,
		   methods based upon a trust-region strategy, and gradient
		   path methods are also considered. When combined with the
		   numerically stable \citebb{BuncParl71} factorization of a
		   symmetric indefinite matrix the latter two approaches give
		   rise to efficient and robust minimization methods
		   which can take advantage of negative curvature.}}

@article{GoldLiuWang91,
 author		= {D. Goldfarb and S. C. Liu and S. Wang},
 title 		= {A Logarithmic Barrier Function Algorithm for Quadratically
           	   Constrained Convex Quadratic Programs},
 journal 	= SIOPT,
 volume 	= 1, number = 2, pages = {252--267}, year = 1991}

@article{GoldWang93,
 author		= {D. Goldfarb and S. Wang},
 title 		= {Partial-update {N}ewton methods for unary, factorable 
                   and partially separable optimization},
 journal     	= SIOPT,
 volume    	= 3, number = 2, pages = {383--397}, year = 1993}

@article{GoldIdna83,
 author 	= {D. Goldfarb and A. Idnani},
 title  	= {A numerically stable dual method for solving strictly convex
          	   quadratic programs},
 journal 	= MP,
 volume 	= 27, number = 1, pages = {1--33}, year = 1983}

@article{GoldLiu93,
 author 	= {D. Goldfarb and S. C. Liu},
 title  	= {An $O(n^3 {L})$ primal dual potential reduction algorithm for
          	   solving convex quadratic programs},
 journal 	= MP,
 volume 	= 61, number = 2, pages = {161--170}, year = 1993}

@article{GoldToin84,
 author		= {D. Goldfarb and Ph. L. Toint},
 title		= {Optimal Estimation of {J}acobian and {H}essian Matrices
		   That Arise in Finite Difference Calculations},
 journal	= MC,
 volume		= 43, number = 167, pages = {69--88}, year = 1984}

@article{GoldQuanTrot66,
 author		= {S. M. Goldfeldt and R. E. Quandt and H. F. Trotter},
 title		= {Maximization by quadratic hill-climbing},
 journal	= {Econometrica},
 volume		= 34, pages = {541--551}, year = 1966,
 abstract	= {The purpose of this paper is to describe a new gradient
		   method for maximizing general functions. After a brief
		   discussion of various known gradient methods the
		   mathematical foundation is laid for the new algorithm which
		   rests on maximizing a quadratic approximation to the
		   function on a suitably chosen spherical region. The method
		   requires no assumptions about the concavity of the function
		   to be maximized and automatically modifies the step size in
		   the light of the success of the quadratic approximation to
		   the function. The paper further discusses some practical
		   problems of implementing the algorithm and presents recent
		   computational experience with it.},
 summary	= {A gradient method for maximizing general functions is
		   discussed. After a brief discussion of various known
		   gradient methods the mathematical foundation is laid for
		   the algorithm which rests on maximizing a quadratic
		   approximation to the function on a suitably chosen
		   spherical region. The method requires no assumptions about
		   the concavity of the function to be maximized and
		   automatically modifies the step size in the light of the
		   success of the quadratic approximation to the function.
		   Practical problems of implementing the algorithm are
		   discussed, and computational experience presented.}}

@article{Gold64,
 author		= {A. A. Goldstein},
 title		= {Convex programming in {H}ilbert space},
 journal	= {Bull. Amer. Math. Soc.},
 volume		= 70, pages = {709--710}, year = 1964}

@article{GoluOLea89,
 author		= {G. H. Golub and D. P. O'Leary},
 title		= {Some history of the conjugate gradient and {L}anczos
		   methods},
 journal	= SIREV,
 volume		= 31, number = 1, pages = {50--102}, year = 1989}

@book{GoluvanL89,
 author		= {G. H. Golub and Van Loan, C. F.},
 title		= {Matrix Computations},
 publisher	= {Johns Hopkins University Press}, address = {Baltimore},
 edition	= {second}, year = 1989}

@article{GoluvonM91,
 author  	= {G. H. Golub and U. von Matt},
 title  	= {Quadratically constrained least squares and quadratic 
                   problems},
 journal 	= NUMMATH,
 volume  	= 59, pages = {561--580}, year = 1991}

@article{GomeMaciMart99,
 author		= {F. A. M. Gomes and M. C. Maciel and J. M. Mart\'{\i}nez},
 title		= {Nonlinear Programming algorithms using trust regions and
		   augmented {L}agrangians with nonmonotone penalty parameters},
 journal        = MP,
 volume         = 84, number = 1, pages = {161--200}, year = 1999,
 abstract	= {A model algorithm based on the successive quadratic
		   programming method for solving the general nonlinear
		   programming problem is presented. The objective function
		   and the constraints of the problem are only required to be
		   differentiable and their gradients to satisfy a Lipschitz
		   condition. The strategy for obtaining global convergence is
		   based on the trust region approach. The merit function is a
		   type of augmented Lagrangian. A new updating scheme is
		   introduced for the penalty parameter, by means of which
		   monotone increase is not necessary. Global convergence
		   results are proved and numerical experiments are presented.},
 summary	= {An algorithm based on the SQP method for solving the
		   general nonlinear programming problem is presented. The
		   objective function and the constraints of the problem are
		   only required to be differentiable and their gradients to
		   satisfy a Lipschitz condition. The strategy for obtaining
		   global convergence is based on a trust-region.
		   The merit function is a type of augmented Lagrangian. An
		   updating scheme is introduced for the penalty parameter, by
		   means of which monotone increase is not necessary. Global
		   convergence results are proved and numerical experiments
		   are presented.}}

@article{Gonz91,
 author		= {C. C. Gonzaga},
 title		= {An interior trust region method for linearly constrained
		   optimization},
 journal	= {COAL Newsletter},
 volume		= 19, pages = {55--66}, year = 1991,
 summary	= {The link between the ellipsoids associated with
		   interior-point methods scaling and trust regions is
		   exposed.}}

@article{GonzTapiPotr98,
 author		= {M. D. Gonzalez{-}Lima and R. A. Tapia and F. A. Potra},
 title		= {On Effectively Computing the Analytic Center of the
		   Solution Set by Primal-Dual Interior-Point Methods},
 journal	= SIOPT,
 volume		= 8, number = 1, pages = {1--25}, year = 1998}

@article{GopaBieg97,
 author		= {V. Gopal and L. T. Biegler},
 title		= {Nonsmooth dynamic simulation with linear programming based
		   methods},
 journal	= {Computers and Chemical Engineering},
 volume		= 21, number = 7, pages = {675--689}, year = 1997,
 abstract	= {Process simulation has emerged as a valuable tool for
		   process design, analysis and operation. In this work, we
		   extend the capabilities of iterated linear programming (LP)
		   for dealing with problems encountered in dynamic nonsmooth
		   process simulation. A previously developed LP method is
		   refined with the addition of a new descent strategy which
		   combines line search with a trust region approach. This
		   adds more stability and efficiency to the method. The LP
		   method has the advantage of naturally dealing with profile
		   bounds as well. This is demonstrated to avoid the
		   computational difficulties which arise from the iterates
		   going into physically unrealistic regions. A new method for
		   the treatment of discontinuities occurring in dynamic
		   simulation problems is also presented in this paper. The
		   method ensures that any event which has occurred within the
		   time interval in consideration is detected and if more than
		   one event occurs, the detected one is indeed the earliest
		   one. A specific class of implicitly discontinuous process
		   simulation problems, phase equilibrium calculations, is
		   also examined. A new formulation is introduced to solve
		   multiphase problems.},
 summary	= {A previously developed LP method is refined with the
		   addition of a descent strategy which combines line
		   search with a trust-region approach.  The LP method has
		   the advantage of naturally dealing with additional profile
		   bounds. A method for the treatment of discontinuities
		   occurring in dynamic simulation problems is also presented.
		   The method ensures that any event which has occurred within
		   the time interval in consideration is detected and if more
		   than one event occurs, the detected one is indeed the
		   earliest one. A specific class of implicitly discontinuous
		   process simulation problems, phase equilibrium
		   calculations, is also examined. A formulation is
		   introduced to solve multiphase problems.}}

@article{GopaBieg98,
 author		= {V. Gopal and L. T. Biegler},
 title		= {A successive linear programming approach for initialization 
                   and reinitialization after discontinuities of 
                   differential-algebraic equations },
 journal	= SISC,
 volume		= 20, number = 2, pages = {447--467}, year = 1998,
 abstract	= {Determination of consistent initial conditions is an 
                   important aspect of the solution of differential-algebraic 
                   equations (DAEs). Specification of inconsistent initial
                   conditions, even if they are only slightly
                   inconsistent, often leads to a failure in the
                   initialization problem. We present a successive
                   linear programming (SLP) approach for the solution of
                   the DAE derivative array equations for the
                   initialization problem. The SLP formulation handles
                   roundoff errors and inconsistent user specifications,
                   among other things, and allows for reliable
                   convergence strategies that incorporate variable
                   bounds and trust region concepts. A new consistent
                   set of initial conditions is obtained by minimizing
                   the deviation of the variable values from the
                   specified ones. For problems with discontinuities
                   caused by a step change in the input functions, a new
                   criterion is presented for identifying the subset of
                   variables which are continuous across the
                   discontinuity. The SLP formulation is then applied to
                   determine a consistent set of initial conditions for
                   further solution of the problem in the domain after
                   the discontinuity. Numerous example problems are
                   solved to illustrate these concepts.},
 summary	= {Determination of consistent initial conditions is an 
                   important aspect of the solution of differential-algebraic 
                   equations (DAEs). Specification of inconsistent initial
                   conditions, even if they are only slightly
                   inconsistent, often leads to a failure in the
                   initialization problem. A successive linear
                   programming (SLP) approach for the solution of the
                   DAE derivative array equations for the initialization
                   problem is proposed. The SLP formulation handles
                   roundoff errors and inconsistent user specifications,
                   among other things, and allows for reliable
                   convergence strategies that incorporate variable
                   bounds and trust region concepts. A new consistent
                   set of initial conditions is obtained by minimizing
                   the deviation of the variable values from the
                   specified ones. For problems with discontinuities
                   caused by a step change in the input functions, a new
                   criterion is presented for identifying the subset of
                   variables which are continuous across the
                   discontinuity. The SLP formulation is then applied to
                   determine a consistent set of initial conditions for
                   further solution of the problem in the domain after
                   the discontinuity. Numerous example problems are
                   solved to illustrate these concepts.}}

@article{Goul85,
 author		= {N. I. M. Gould},
 title		= {On practical conditions for the existence and uniqueness of
		   solutions to the general equality quadratic-programming
		   problem},
 journal	= MP,
 volume		= 32, number = 1, pages = {90--99}, year = 1985}

@article{Goul86,
 author		= {N. I. M. Gould},
 title		= {On the accurate determination of search directions for
		   simple differentiable penalty functions},
 journal	= IMAJNA,
 volume		= 6, pages = {357--372}, year = 1986}
 
@article{Goul89,
 author		= {N. I. M. Gould},
 title		= {On the convergence of a sequential penalty function method
		   for constrained minimization},
 journal	= SINUM,
 volume		= 26, number = 1, pages = {107--128}, year = 1989}

@article{Goul91,
 author		= {N. I. M. Gould},
 title		= {An algorithm for large-scale quadratic programming},
 journal	= IMAJNA,
 volume		= 11, number = 3, pages = {299--324}, year = 1991}

@article{Goul99,
 author		= {N. I. M. Gould},
 title		= {On modified factorizations for large-scale
                   linearly-constrained optimization}, 
 journal        = SIOPT,
 volume         = 9, number = 4, pages = {1041--1063}, year = 1999}

@inproceedings{Goul99b,
 author         = {N. I. M. Gould},
 title          = {Iterative methods for ill-conditioned linear systems from 
                   optimization},
 crossref       = {DiPiGian99}, pages = {123--142}}

@inproceedings{GoulLuciRomaToin98,
 author		= {N. I. M. Gould and S. Lucidi and M. Roma and Ph. L. Toint},
 title		= {A linesearch algorithm with memory for unconstrained
		   optimization},
 crossref       = {DeLeMurlPardTora98}, pages = {207--223}}

@article{GoulLuciRomaToin99,
 author		= {N. I. M. Gould and S. Lucidi and M. Roma and Ph. L. Toint},
 title		= {Solving the trust-region subproblem using the {L}anczos
		   method},
 journal	= SIOPT,
 volume		= 9, number = 2, pages = {504--525}, year = 1999,
 abstract	= {The approximate minimization of a quadratic function within
		   an ellipsoidal trust region is an important subproblem for
		   many nonlinear programming methods. When the number of
		   variables is large, the most widely-used strategy is to
		   trace the path of conjugate gradient iterates either to
		   convergence or until it reaches the trust-region boundary.
		   In this paper, we investigate ways of continuing the
		   process once the boundary has been encountered. The key is
		   to observe that the trust-region problem within the
		   currently generated Krylov subspace has very special
		   structure which enables it to be solved very efficiently.
		   We compare the new strategy with existing methods. The
		   resulting software package is available as {\tt HSL\_VF05}
		   within the \citebb{HSL00}.},
 summary	= {When the number of variables is large, the most widely-used
		   strategy for solving the trust-region subproblem is to
		   trace the path of conjugate gradient iterates either to
		   convergence or until it reaches the trust-region boundary.
		   Means of continuing the process once the boundary has been
		   encountered are investigated. One observes that the
		   trust-region problem within the currently generated Krylov
		   subspace has very special structure which enables it to be
		   solved efficiently. The proposed strategy is compared with
		   existing methods.}}

@inproceedings{GoulNoce98,
 author		= {N. I. M. Gould and J. Nocedal},
 title		= {The modified absolute-value factorization norm for
		   trust-region minimization},
 crossref       = {DeLeMurlPardTora98}, pages = {225--241},
 abstract	= {A trust-region method for unconstrained minimization, using
		   a trust-region norm based upon a modified absolute-value
		   factorization of the model Hessian, is proposed. It is
		   shown that the resulting trust-region subproblem may be
		   solved using a single factorization. In the convex case,
		   the method reduces to a backtracking Newton linesearch
		   procedure. The resulting software package is available as
		   {\tt HSL\_VF06} within the \citebb{HSL00}. Numerical
		   evidence shows that the approach is effective in the
		   nonconvex case.},
 summary        = {A trust-region method for unconstrained minimization,
                   using a trust-region norm based upon a modified
                   absolute-value factorization of the model Hessian, is
                   proposed. It is shown that the resulting trust-region
                   subproblem may be solved using a single
                   factorization. In the convex case, the method reduces
                   to a backtracking Newton linesearch procedure. Numerical
                   experience suggests that the approach is effective in the
                   non-convex case.}}

@techreport{GoulOrbaSartToin99,
 author		= {N. I. M. Gould and D. Orban and A. Sartenaer 
		   and Ph. L. Toint},
 title		= {On the Practical Dependency of a Trust-Region Algorithm
		   on its Parameters},
 institution	= FUNDP, address = FUNDP-ADDRESS,
 number		= {(in preparation)}, year = 1999,
 abstract       = {In this paper, it is shown through numerical tests that
		   commonly accepted values for the parameters of a
		   trust-region algorithm might not be the best ones.  Better
		   ranges of values for these parameters are exhibited on a
		   statistical basis.  It is also shown what improvements can
		   be hoped for when using a band preconditioner.},
 summary	= {An extensive numerical study of the statistically best 
		   ranges for the trust-region algorithm parameters is
		   described, whose conclusions differ from folklore
		   knowledge. The impact of preconditioning on parameter
		   choice and performance is also discussed.}} 

@techreport{GoulOrbaSartToin99b,
 author		= {N. I. M. Gould and D. Orban and A. Sartenaer 
		   and Ph. L. Toint},
 title          = {On the Local Convergenve of a Primal-Dual Trust-Region
                   Interior-Point Algorithm for Constrained Nonlinear
                    Programming},
 institution	= FUNDP, address = FUNDP-ADDRESS,
 number		= {(in preparation)}, year = 1999,
 abstract       = {The local convergence properties of the trust-region
                   interior-point method described in
                   \citebb{ConnGoulOrbaToin99} are analyzed. It is shown that
                   the method asymptotically require a single inner iteration
                   per outer iteration and converges 2-step supercubically.},
 summary        = {The local convergence properties of the trust-region
                   interior-point method described in
                   \citebb{ConnGoulOrbaToin99} are analyzed. It is shown that
                   the method asymptotically require a single inner iteration
                   per outer iteration and converges 2-step supercubically.}}

@article{GoulToin99,
 author		= {N. I. M. Gould and Ph. L. Toint},
 title		= {A Note on the Second-Order Convergence of Optimization
		   Algorithms Using Barrier Functions},
 journal        = MP,
 volume         = 85, number = 2, pages = {433--438}, year = 1999}

@inproceedings{GoulToin99b,
 author         = {N. I. M. Gould and Ph. L. Toint},
 title          = {{SQP} methods for large-scale nonlinear programming},
 booktitle      = {System Modelling and Optimization, 
                   Methods, Theory and Applications},
 editor         = {M. J. D. Powell and S. Scholtes},
 publisher      = KLUWER, address = KLUWER-ADDRESS,
 pages          = {149--178}, year = 2000,
 abstract       = {We compare and contrast a number of recent sequential
                   quadratic programming (SQP) methods that have been proposed 
                   for the solution of large-scale nonlinear programming
                   problems. Both line-search and trust-region approaches
                   are considered, as are the implications of interior-point
                   and quadratic programming methods.},
 summary        = {A comparison is proposed of a number of recent SQP methods
                   for the solution of large-scale nonlinear programming
                   problems. Both linesearch and trust-region approaches
                   are considered, as are the implications of interior-point
                   and quadratic programming methods.}}

@techreport{GoulHribNoce98,
 author		= {N. I. M. Gould and M. E. Hribar and J. Nocedal},
 title		= {On the solution of equality constrained quadratic problems
		   arising in optimization},
 institution	= RAL, address = RAL-ADDRESS,
 number		= {RAL-TR-98-069}, year = 1998}

@article{GoulToll72,
 author		= {F. J. Gould and J. W. Tolle},
 title		= {Geometry of optimality conditions and constraint
		   qualifications},
 journal	= MP,
 volume		= 2, number = 1, pages = {1--18}, year = 1972}

@article{GowGuoLiuLuci97,
 author		= {A. S. Gow and X. Z. Guo and D. L. Liu and A. Lucia},
 title		= {Simulation of refrigerant phase equilibria},
 journal	= {Industrial and Engineering Chemistry Research},
 volume		= 36, number = 7, pages = {2841--2848}, year = 1997,
 abstract	= {Vapor-liquid equilibria for refrigerant mixtures modeled by
		   an equation of state are studied. Phase behavior calculated
		   by the Soave-Redlich-Kwong (SRK) equation with a single
		   adjustable binary interaction parameter is compared with
		   experimental data for binary refrigerant mixtures, two with
		   a supercritical component and one that exhibits azeotropic
		   behavior. It is shown that the SRK equation gives an
		   adequate description of the-phase envelope for binary
		   refrigerant systems. The complex domain trust region
		   methods of Lucia and co- workers (\bciteb{LuciGuoWang93},
		   \bciteb{LuciXu94}) are applied to fixed vapor, isothermal
		   flash model equations, with particular attention to root
		   finding and root assignment at the equation of state (EOS)
		   level of the calculations, and convergence in the
		   retrograde and azeotropic regions of the phase diagram.
		   Rules far assigning roots to the vapor and liquid phases in
		   the case where all roots to the EOS are complex- valued are
		   proposed and shown to yield correct results, even in
		   retrograde regions. Convergence of the flash model
		   equations is also studied. It is shown that the complex
		   domain trust region algorithms outperform Newton's method
		   in singular regions of the phase diagram (i.e., at near
		   azeotropic conditions and in the retrograde loop),
		   primarily due to the eigenvalue-eigenvector decomposition
		   strategy given in Sridhar and Lucia (1995). A variety of
		   geometric figures are used to illustrate salient points.},
 summary	= {Vapor-liquid equilibria for refrigerant mixtures modeled by
		   an equation of state are studied. Phase behaviour
		   calculated by the Soave-Redlich-Kwong (SRK) equation with a
		   single adjustable binary interaction parameter is compared
		   with experimental data for binary refrigerant mixtures, two
		   with a supercritical component and one that exhibits
		   azeotropic behaviour. It is shown that the SRK equation
		   gives an adequate description of the-phase envelope for
		   binary refrigerant systems. The complex domain trust-region
		   methods of \citebb{LuciGuoWang93} and \citebb{LuciXu94} are
		   applied to fixed vapor, isothermal flash model equations,
		   with particular attention to root finding and root
		   assignment at the equation of state (EOS) level of the
		   calculations, and convergence in the retrograde and
		   azeotropic regions of the phase diagram. Rules for
		   assigning roots to the vapor and liquid phases in the case
		   where all roots to the EOS are complex- valued 
		   yield correct results, even in retrograde
		   regions. Convergence of the flash model equations is also
		   studied. It is shown that the complex domain trust-region
		   algorithms outperform Newton's method in singular regions
		   of the phase diagram. A variety of geometric figures are
		   used to illustrate salient points.}}

@article{GreeStra92,
 author		= {A. Greenbaum and Z. Strako\v{s}},
 title		= {Predicting the behaviour of finite precision {L}anczos and
		   conjugate gradient computations},
 journal	= SIMAA,
 volume		= 13, number = 1, pages = {121--137}, year = 1992}

@article{Gree67,
 author		= {J. Greenstadt},
 title		= {On the relative efficiencies of gradient methods},
 journal	= MC,
 volume		= 21, pages = {360--367}, year = 1967}

@book{Gree97,
 author		= {A. Greenbaum},
 title		= {Iterative Methods for Solving Linear Systems},
 publisher	= SIAM, address = SIAM-ADDRESS,
 year		= 1997}

@inproceedings{Grie89,
 author		= {A. Griewank},
 title		= {On automatic differentiation},
 crossref	= {IriTana89}, pages = {83--108}}

@inproceedings{Grie94,
 author		= {A. Griewank},
 title		= {Computational Differentiation and Optimization},
 booktitle	= {Mathematical Programming: State of the Art 1994},
 editor		= {J. R. Birge and K. G. Murty},
 publisher	= {The University of Michigan}, address = {Ann Arbor, USA},
 pages		= {102--131}, year = 1994}

@book{GrieCorl91,
 author		= {A. Griewank and G. Corliss},
 title		= {Automatic Differentiation of Algorithms: Theory,
		   Implementation and Application},
 publisher	= SIAM, address = SIAM-ADDRESS,
 year		= 1991}

@inproceedings{GrieToin82a,
 author		= {A. Griewank and Ph. L. Toint},
 title		= {On the unconstrained optimization of partially separable
		   functions},
 crossref	= {Powe82}, pages = {301--312}}

@article{GrieToin82b,
 author		= {A. Griewank and Ph. L. Toint},
 title		= {Partitioned variable metric updates for large structured
		   optimization problems},
 journal	= NUMMATH,
 volume		= 39, pages = {119--137}, year = 1982}

@article{GrifStew61,
 author		= {R. E. Griffith and R. A. Stewart},
 title		= {A nonlinear programming technique for the optimization of
		   continuous processing systems},
 journal	= {Management Science},
 volume		= 7, pages = {379--392}, year = 1961,
 abstract	= {A description is given of a method for solving some
		   nonlinear programming problems. The mathematics of this
		   method are quite simple and are easy to apply to electronic
		   computation. A numerical example, a model construction
		   example, and a description of a particular existing
		   computer system are included in order to clarify the mode
		   of operation of the method.},
 summary	= {A simple method for solving nonlinear programming problems
		   is given. A numerical example, a model construction
		   example, and a description of a particular existing
		   computer system are included in order to clarify the mode
		   of operation of the method.}}

@article{GripLampLuci86,
 author		= {L. Grippo and F. Lampariello and S. Lucidi},
 title		= {A nonmonotone line search technique for {N}ewton's method},
 journal	= SINUM,
 volume		= 23, number = 4, pages = {707--716}, year = 1986}

@article{GripLampLuci89,
 author		= {L. Grippo and F. Lampariello and S. Lucidi},
 title		= {A Truncated {N}ewton Method with Nonmonotone Line Search
		   for Unconstrained Optimization},
 journal	= JOTA,
 volume		= 60, number = 3, pages = {401--419}, year = 1989}

@article{GripLampLuci91,
 author		= {L. Grippo and F. Lampariello and S. Lucidi},
 title		= {A class of nonmonotone stabilization methods in
		   unconstrained optimization},
 journal	= NUMMATH,
 volume		= 59, pages = {779--805}, year = 1991}

@techreport{GrotMcKi98,
 author		= {A. Grothey and K. McKinnon},
 title		= {A Superlinearly Convergent Trust Region Bundle Method},
 institution	= {Department of Mathematics and Statistics},
 address        = {Univeristy of Edinburgh, Scotland},
 number		= {MS 98-015}, year = 1998,
 abstract	= {Bundle methods for the minimization of non-smooth 
                   functions have been around for almost 20 years. 
                   Numerous variations have been proposed. But until very
                   recently they all suffered from the drawback of only
                   linear convergence. The aim of this paper is to show
                   how exploiting an analogy with SQP gives rise to a
                   superlinearly convergent bundle method. Our algorithm
                   features a trust region philosophy and is expected to
                   converge superlinearly even for non-convex problems.},
 summary	= {Current bundle methods for the minimization of non-smooth 
                   functions converge at a linear rate. A superlinearly
                   convergent bundle method, using a trust region, is
                   proposed for nonconvex problems. Numerical experience
                   on a power-generation problem is reported.}}

@article{Gurw94,
 author		= {C. Gurwitz},
 title		= {Local Convergence of a Two-Piece Update of a Projected
		   {H}essian Matrix},
 journal	= SIOPT,
 volume		= 4, number = 3, pages = {461--485}, year = 1994}


@book{GruvSach80,
 author		= {W. A. Gruver and E. W. Sachs},
 title		= {Algorithmic Methods in Optimal Control},
 publisher	= {Pitman}, address = {Boston, USA},
 year		= 1980}

%%% H %%%

@book{Hack94,
 author		= {W. Hackbusch},
 title		= {Iterative Solution of Large Sparse Systems of Equations},
 publisher	= SPRINGER, address = SPRINGER-ADDRESS,
 series		= {Springer Series in Applied Mathematical Sciences},
 year		= 1994}

@article{Hage87,
 author		= {W. W. Hager},
 title		= {Dual techniques for constrained optimization},
 journal	= JOTA,
 volume		= 55, pages = {37--71}, year = 1987}

@article{Hage99,
 author		= {W. W. Hager},
 title		= {Stabilized sequential quadratic programming},
 journal        = COAP,
 volume         = 12, number = {1--2}, pages = {253--273}, year = 1999}

@techreport{Hage99b,
 author		= {W. W. Hager},
 title		= {Minimizing a Quadratic Over a Sphere},
 institution	= {Mathematics Department, University of Florida}, 
 address        = {Gainesville, Florida, USA},
 month          = {May}, year = 1999,
 abstract       = {A new method, the sequential subspace method (SSM), 
                   is developed for minimizing a quadratic over a
                   sphere. In each iteration of the scheme, the
                   quadratic is minimized over a subspace that contains
                   the prior iterate, a sequential quadratic programming
                   iterate, and a projected gradient. A low dimensional
                   subspace with these properties is obtained using the
                   transformed minimal residual algorithm (TMRES). We
                   prove that the SSM is locally quadratically
                   convergent. Numerical experiments indicate that the
                   SSM requires far fewer matrix-vector operations than
                   other recently developed algorithms.},
 summary        = {A sequential subspace method (SSM),  is developed for
                   minimizing a quadratic over a sphere. In each iteration,
                   the quadratic is minimized over a subspace that contains
                   the prior iterate, a sequential quadratic programming
                   iterate, and a projected gradient. A low dimensional
                   subspace with these properties is obtained using the
                   transformed minimal residual algorithm (TMRES).
                   The SSM is proved to be locally quadratically
                   convergent. Numerical experiments indicate that the
                   SSM requires few matrix-vector operations.}}

@article{Han77,
 author		= {S. P. Han},
 title		= {A Globally Convergent Method for Nonlinear Programming},
 journal	= JOTA,
 volume		= 22, number = 3, pages = {297--309}, year = 1977}

@article{HanMang79,
 author		= {S. P. Han and O. L. Mangasarian},
 title		= {Exact penalty functions in nonlinear programming},
 journal	= MP,
 volume		= 17, number = 3, pages = {251--269}, year = 1979}

@article{HanMang83,
 author		= {S. P. Han and O. L. Mangasarian},
 title		= {A dual differentiable exact penalty-function},
 journal	= MP,
 volume		= 25, number = 3, pages = {293--306}, year = 1983}

@article{HanPardYe92,
 author		= {C. Han and P. Pardalos and Y. Ye},
 title		= {On the solution of indefinite quadratic problems using an
		   interior point method},
 journal	= {Informatica},
 volume		= 3, pages = {474--496}, year = 1992}

@techreport{HanHan99,
 author         = {Q. Han and J. Han},
 title          = {Modified Quasi-{N}ewton Method with Collinear Scaling for
		   Unconstrained Optimization}, 
 institution    = {Institute of Computational Mathematics and 
                   Scientific/Engineering Computing, 
                   Chinese Academy of Sciences},
 address        = {Beijing},
 number         = {February}, year = 1999,
 abstract       = {It is well known that among the current methods for
		   unconstrained optimization problems, Newton or quasi-Newton
		   method with global strategy may be the most efficient
	 	   method, which have local quadratic or superlinear
		   convergence.  However, when the iterate point is far away
		   from the a solution of the problem, Newton or quasi-Newton
		   method may proceed slowly for the general nonlinear
		   objective function.  In the paper, we present a modified 
		   quasi-Newton method with trust region using the collinear
		   scaling for unconstrained optimization.  Not only the
		   gradient information but the values of the objective
		   function are used to construct the local model at the 
		   current iteration point.  Moreover, the information about
		   the super steepest descent direction is embedded into the
		   local model.  the amount of computation in each iteration
		   of the modified quasi-Newton method algorithm with trust 
		   region is the same as that of the standard quasi-Newton
		   method with trust region. And some numerical results show
	 	   that the modified method needs very fewer iterations to
		   reach the solution of the optimization problem.  Global 
		   and local convergence of the method is also analyzed.},
 summary        = {A trust-region method is proposed for unconstrained
                   minimization, where the model is obtained by a conic
                   quasi-Newton update.  The trust region is defined not in
                   the original space but in the space of collinearly scaled
                   variables. Limited numerical experience illustrates the
                   practical potential of the method.}}

@article{Hank97,
 author		= {M. Hanke},
 title		= {A regularizing {L}evenberg-{M}arquardt scheme, with
		   applications to inverse groundwater filtration problems},
 journal	= {Inverse Problems},
 volume		= 13, number = 1, pages = {79--95}, year = 1997,
 abstract	= {The first part of this paper studies a Levenberg-Marquardt
		   scheme for nonlinear inverse problems where the
		   corresponding Lagrange (or regularization) parameter is
		   chosen from an inexact Newton strategy. While the
		   convergence analysis of standard implementations based on
		   trust region strategies always requires the invertibility
		   of the Frechet derivative of the nonlinear operator at the
		   exact solution, the new Levenberg-Marquardt scheme is
		   suitable for ill-posed problems as long as the Taylor
		   remainder is of second order in the interpolating metric
		   between the range and domain topologies. Estimates of this
		   type are established in the second part of the paper for
		   ill-posed parameter identification problems arising in
		   inverse groundwater hydrology. Both transient and
		   steady-state data are investigated. Finally, the numerical
		   performance of the new Levenberg-Marquardt scheme is
		   studied and compared to a usual implementation on a
		   realistic but synthetic two-dimensional model problem from
		   the engineering literature.},
 summary	= {A Levenberg-Morrison-Marquardt scheme for nonlinear
		   inverse problems is considered, where the corresponding
		   Lagrange parameter is chosen from an inexact Newton
		   strategy. This scheme is suitable for ill-posed problems as
		   long as the Taylor remainder is of second order in the
		   interpolating metric between the range and domain
		   topologies. Estimates of this type are established for
		   ill-posed parameter identification problems arising in
		   inverse groundwater hydrology. Both transient and
		   steady-state data are investigated. The performance of the
		   scheme is compared to a usual implementation on a 
		   two-dimensional engineering model problem.}}

@article{HansKrog92,
 author		= {R. J. Hanson and F. T. Krogh},
 title		= {A Quadratic-Tensor Model Algorithm for Nonlinear
		   Least-Squares Problems with Linear Constraints},
 journal	= TOMS,
 volume		= 18, number = 2, pages = {115--133}, year = 1992,
 abstract       = {A new algorithm is presented for solving nonlinear
                   least-squares and nonlinear equation problems. The
                   algorithm is based on approximating the nonlinear
                   functions using the quadratic-tensor model proposed
                   by Schnabel and Frank (1984). The problem statement
                   may include simple bounds or more general linear
                   constraints on the unknowns. The algorithm uses a
                   trust-region defined by a box containing the current
                   values of the unknowns. The objective function
                   (Euclidean length of the functions) is allowed to
                   increase at intermediate steps. These increases are
                   allowed as long as the predictor indicates that a new
                   set of best values exists in the trust-region. There
                   is logic provided to retreat to the current best
                   values, should that be required. The computations for
                   the model-problem require a constrained nonlinear
                   least-squares solver. This is done using a simpler
                   version of the algorithm. In its present form the
                   algorithm is effective for problems with linear
                   constraints and dense Jacobian matrices. Results on
                   standard test problems are presented in the
                   Appendix. The new algorithm appears to be efficient
                   in terms of function and Jacobian evaluations.},
 summary        = {A new algorithm is presented for solving linearly
		   constrained nonlinear least-squares and nonlinear equation
		   problems, based on approximating the nonlinear
                   functions using the quadratic-tensor model.
                   The algorithm uses a box-shaped
                   trust-region. The objective function
                   is allowed to increase at intermediate steps,
                   as long as the predictor indicates that a new
                   set of best values exists in the trust-region. There
                   is logic provided to retreat to the current best
                   values, if necessary. The algorithm is effective for
		   problems with linear constraints and dense Jacobian
		   matrices and appears to be efficient
                   in terms of function and Jacobian evaluations.}}

@article{HarkPang90,
 author		= {P. T. Harker and J. S. Pang},
 title		= {Finite-dimensional variational inequality and nonlinear
		   complementarity problems: a survey of theory, algorithms
		   and applications},
 journal	= MPB,
 volume		= 48, number = 2, pages = {161--220}, year = 1990}

@article{HarkXiao90,
 author		= {P. T. Harker and B. Xiao},
 title		= {{N}ewton's method for the nonlinear complementarity
		   problem: a {B}-differentiable equation approach},
 journal	= MPB,
 volume		= 48, number = 3, pages = {339--358}, year = 1990}

@article{HeDiaoGao97,
 author		= {G. He and B. Diao and Z. Gao},
 title		= {An {SQP} algorithm with nonmonotone line search for general
		   nonlinear constrained optimization problem},
 journal	= JCM,
 volume		= 15, number = 2, pages = {179--192}, year = 1997}

@techreport{Hebd73,
 author		= {M. D. Hebden},
 title		= {An Algorithm for Minimization Using Exact Second
		   Derivatives},
 institution	= HARWELL, address = HARWELL-ADDRESS,
 number		= {T.P. 515}, year = 1973,
 abstract	= {A review of the methods currently available for the
		   minimization of a function whose first and second
		   derivatives can be calculated shows either that the method
		   requires the eigensolution of the Hessian, or with one
		   exception that a simple example can be found which causes
		   the method to fail. In this paper one of the successful
		   methods that requires the eigensolution is modified so that
		   at each iteration the solution of a number (approximately
		   two) of systems of linear equations is required, instead of
		   the eigenvalue calculation.},
 summary	= {A method for the solution of the $\ell_2$ trust-region
		   subproblem is proposed so that at each iteration the
		   solution of a number (roughly two) of systems of linear
		   equations is required, instead of the eigenvalue
		   calculation.}}

@article{Hein93,
 author		= {M. Heinkenschloss},
 title		= {Mesh Independence for Nonlinear Least Squares Problems with
		   Norm Constraints},
 journal	= SIOPT,
 volume		= 3, number = 1, pages = {81--117}, year = 1993}

@article{Hein94,
 author		= {M. Heinkenschloss},
 title		= {On the solution of a two ball trust region subproblem},
 journal	= MP,
 volume		= 64, number = 3, pages = {249--276}, year = 1994,
 abstract	= {In this paper we investigate the structure of a two ball
		   trust region subproblem arising in nonlinear parameter
		   identification problems and propose a method for its
		   solution. The method decomposes the subproblem and allows
		   the application of efficient, well studied methods for the
		   solution of the trust region subproblems arising in
		   unconstrained optimization. In the discussion of the
		   structure we focus on the case where both constraints are
		   active and on the treatment of the unconstrained problem.},
 summary	= {The structure of a two-ball trust-region subproblem arising
		   in nonlinear parameter identification problems is
		   investigated, and a method for its solution is proposed.
		   The method decomposes the subproblem, and allows the
		   application of efficient methods for the
		   solution of the trust-region subproblems. The discussion 
		   of the structure 
		   focuses on the case where both constraints are active and
		   on the treatment of the unconstrained problem.}}

@article{Hein98,
 author		= {M. Heinkenschloss},
 title		= {A Trust-Region Method for Norm Constrained Problems},
 journal	= SINUM,
 volume		= 35, number = 4, pages = {1594--1620}, year = 1998,
 abstract	= {In this paper a trust region method for the solution of
		   nonlinear optimization problems with norm constraints is
		   presented and analyzed. Such problems often arise in
		   parameter identification or nonlinear eigenvalue problems.
		   The algorithms studied here allow for inexact gradient
		   information and the use of subspace methods for the
		   approximate solution of subproblems. Characterizations and
		   the descent properties of trust region steps are given,
		   criteria for the existence of successful iterations under
		   inexact gradient information and under the use of subspace
		   methods are established, and global convergence of the
		   method is proven.},
 summary	= {A trust-region method for the solution of nonlinear
		   optimization problems with norm constraints is presented
		   and analyzed. Such problems often arise in parameter
		   identification or nonlinear eigenvalue problems. The
		   algorithms studied allow for inexact gradient information
		   and the use of subspace methods for the approximate
		   solution of subproblems. Characterizations and the descent
		   properties of trust-region steps are given, criteria for
		   the existence of successful iterations under inexact
		   gradient information and under the use of subspace methods
		   are established, and global convergence of the method is
		   proven.}}

@techreport{HeinUlbrUlbr97,
 author		= {M. Heinkenschloss and M. Ulbrich and S. Ulbrich},
 title		= {Superlinear and quadratic convergence of affine-scaling
		   interior-point {N}ewton methods for problems with simple
		   bounds without strict complementarity},
 institution	= CAAM, address = RICE-ADDRESS,
 number		= {TR97-30}, year = 1997,
 abstract	= {A class of affine-scaling interior-point methods for bound
		   constrained optimization problems is introduced which are
		   locally q-superlinearly or q-quadratically convergent. It
		   is assumed that the strong second order sufficient
		   optimality conditions at the solution are satisfied, but
		   strict complementarity is not required. The methods are
		   modifications of the affine-scaling interior-point Newton
		   methods introduced by \citebb{ColeLi94}. There are two
		   modifications. One is a modification of the scaling matrix,
		   the other one is the use of a projection of the step to
		   maintain strict feasibility rather than a simple scaling of
		   this step. A comprehensive local convergence analysis is
		   given. A few simple examples are presented to illustrate
		   the pitfalls of the original approach of
		   \citeauthor{ColeLi94} in the degenerate case and to
		   demonstrate the performance of the fast converging
		   modifications developed in this paper.},
 summary	= {A class of affine-scaling interior-point methods for
		   bound-constrained optimization problems is introduced which
		   are locally Q-superlinearly or Q-quadratically convergent,
		   even without assuming strict complementarity. The methods
		   are derived from \citebb{ColeLi94} but use a different
		   scaling matrix and a projection of the step to maintain
		   strict feasibility. Simple examples are presented to
		   illustrate the pitfalls of \citeauthor{ColeLi94}'s approach
		   in the degenerate case and to demonstrate the performance
		   of the fast converging modifications.}}

@techreport{HeinVice95,
 author		= {M. Heinkenschloss and L. N. Vicente},
 title		= {Analysis of Inexact Trust Region Interior-Point {SQP}
		   Algorithms},
 institution	= CRPC, address = RICE-ADDRESS,
 type		= {Technical Report}, number = {CRPC-TR95546}, year = 1995,
 abstract	= {In this paper we analyze inexact trust-region
		   interior-point (TRIP) sequential quadratic programming
		   (SQP) algorithms for the solution of optimization problems
		   with nonlinear equality constraints and simple bound
		   constraints on some of the variables. Such problems arise
		   in many engineering applications, in particular in optimal
		   control problems with bounds on the control. The nonlinear
		   constraints often come from the discretization of partial
		   differential equations. In such cases the calculation of
		   derivative information and the solution of the linearized
		   equations is expensive. Often, the solution of linear
		   systems and directional derivatives are computed inexactly
		   yielding nonzero residuals. This paper analyzes the effect
		   of the inexactness onto the convergence of TRIP SQP and
		   gives practical rules to control the size of the residuals
		   of these inexact calculations. It is shown that if the size
		   of the residuals is of the order of both the size of the
		   constraints and the trust region radius, then the TRIP SQP
		   algorithms are globally first-order convergent. Numerical
		   experiments with two optimal control problems governed by
		   nonlinear partial differential equations are reported.},
 summary	= {Inexact trust-region interior-point (TRIP) sequential
		   quadratic programming (SQP) algorithms for the solution of
		   optimization problems with nonlinear equality constraints
		   and simple bound constraints are analysed. The effect of
		   the inexactness in the computation of derivative
		   information on the convergence of TRIP SQP is analysed, and
		   practical rules to control the size of the associated
		   residuals are given. It is shown that if the size of the
		   residuals is of the order of both the size of the
		   constraints and the trust region radius, then the TRIP SQP
		   algorithms are globally first-order convergent. Numerical
		   experiments with two optimal control problems governed by
		   nonlinear partial differential equations are reported.}}
%also
%institution = CAAM, address = RICE-ADDRESS, 
%number = {TR95-18}, year = 1995,

@techreport{HeinVice99,
 author		= {M. Heinkenschloss and L. N. Vicente},
 title		= {Analysis of Inexact Trust Region {SQP} Algorithms},
 institution    = COIMBRA, address = COIMBRA-ADDRESS,
 number         = {99-15}, year = 1999,
 abstract       = {In this paper we study the global convergence behavior of
                   a class of composite-step trust-region SQP methods that
                   allow inexact problem information.  The inexact problem
                   information can result from iterative linear systems
                   solves within the trust-region SQP method or from
                   approximations of first-order derivatives.  Accuracy 
                   requirements in our trust-region SQP methods are adjusted
                   based on feasibility and optimality of the iterates. In
                   the absence of inexactness, our global convregence theory
                   is equal to that of \citebb{DennElAlMaci97}.  If all
                   iterates are feasible, i.e.\ if all iterates satisfy the
                   equality constraints, then our results are related to the
                   known convergence analyses for trust-region methods with
                   inexact gradient information for unconstrained
                   optimization.},
 summary        = {The global convergence behaviour of a class of 
                   composite-step trust-region SQP methods that allow inexact
                   problem information is studied.  This inexact
                   information can result from iterative linear systems
                   solves within the trust-region SQP method or from
                   approximations of first-order derivatives.  Accuracy 
                   requirements are based on feasibility and optimality of
                   the iterates. In the absence of inexactness, the analysis
                   reduces to that of \citebb{DennElAlMaci97}. If all iterates
                   satisfy the equality constraints, then the results are
                   related to the known convergence properties for trust-region
                   methods with inexact gradient information in unconstrained
                   optimization.}}

@article{HeinSpel94,
 author		= {J. Heinz and P. Spellucci},
 title		= {A successful implementation of the {P}antoja-{M}ayne {SQP}
		   method},
 journal	= OMS,
 volume		= 4, number = 1, pages = {1--28}, year = 1994}


@article{HelfZwic95,
 author         = {H.-P. Helfrich and D. Zwick},
 title          = {Trust region algorithms for the nonlinear least distance 
                   problem},
 journal        = {Numerical Algorithms},
 volume         = 9, number = {1-2}, pages = {171--179}, year = 1995,
 abstract       = {The nonlinear least distance problem is a special
                   case of equality constrained optimization. Let a
                   curve or surface be given in implicit form via the
                   equation $f(x)=0$, $x \in \Re^d$, and let $z
                   \in $R^d$ be a fixed data point. We discuss
                   two algorithms for solving the following problem:
                   Find a point $x^*$ such that $f(x^*)=0$ and
                   $\|z-x^*\|_2$ is minimal among all such
                   $x$. The algorithms presented use the trust region
                   approach in which, at each iteration, an
                   approximation to the objective function or merit
                   function is minimized in a given neighborhood (the
                   trust region) of the current iterate. Among other
                   things, this allows one to prove global convergence
                   of the algorithm.},
 summary        = {Trust-region algorithms are presented for the nonlinearly
		   constrained least-distance problem.  Global convergence is
		   proved.}}

@article{HelfZwic96,
 author		= {H. P. Helfrich and D. Zwick},
 title		= {A trust region algorithm for parametric curve and surface
		   fitting},
 journal	= JCAM,
 volume		= 73, number = {1--2}, pages = {119--134}, year = 1996,
 abstract	= {Let a family of curves or surfaces be given in parametric
		   form via the model equation $x=f(s,\beta)$ where $x \in
		   \Re^n$, $\beta \in \Re^m$, and $s \in S \subset \Re^d$,
		   $d<n$. We present an algorithm for solving the problem:
		   \emph{Find a shape vector $\beta_*$ such that the manifold
		   $M^*$ is a best fit to scattered data $\{z_i\}_{i=1}^N
		   \subset \Re^n$ in the sense that, for some
		   $\{s_i^*\}_{i=1}^N$, the sum of the squared least distances
		   ` $\sum_{i=1}^N \| z_i - f(s_i^*,\beta^*) \||_2^2$ from the
		   data points to the manifold $M^*$ is minimal among all such
		   manifolds.} For robustness, our algorithm uses a globally
		   convergent trust region approach in which, at each
		   iteration, an approximation to the objective function is
		   minimized in a given neighborhood of the current iterate.
		   The set $S$ may be all of $\Re^d$ or a closed, convex
		   subset. In particular, it may be chosen so that our theory
		   is applicable to splines.},
 summary	= {An algorithm is presented for solving the problem of
		   finding a parameter (shape) vector such that the associated
		   manifold is a best least-squares fit to scattered data.
		   For robustness, the algorithm uses a globally convergent
		   trust-region approach. The support set for the manifold may
		   be all of $\Re^d$ or a closed, convex subset. In
		   particular, it may be chosen so that our theory is
		   applicable to splines.}}

@article{Helg91,
 author		= {T. Helgaker},
 title		= {Transition-State Optimizations by Trust-Region Image
		   Minimization},
 journal	= {Chemical Physics Letters},
 volume		= 182, number = 5, pages = {503--510}, year = 1991,
 abstract	= {A new method for optimizing transition states is presented.
		   The method combines Smith's image function with
		   trust-region minimization. Calculations on HCN and
		   C$_2$H$_6$ illustrate the usefulness of the method for ab
		   initio potential energy surfaces. It is found that
		   second-order image optimizations of transition states are
		   as fast as conventional minimizations.},
 summary	= {A method for optimizing transition states is presented.
		   The method combines Smith's image function with
		   trust-region minimization. Calculations on HCN and C2H6
		   illustrate the usefulness of the method for ab-initio
		   potential energy surfaces. It is found that second-order
		   image optimizations of transition states are as fast as
		   conventional minimizations.}}

@article{HelgAlml88,
 author         = {T. Helgaker and J. Almlof},
 title          = {Molecular wave functions and properties calculated using 
                   floating Gaussian orbitals},
 journal        = {Journal of Chemical Physics},
 volume         = 89, number = 8, pages = {4889-4902}, year = {1988},
 abstract       = {The calculation of molecular electronic wave
                   functions and properties using floating Gaussian
                   orbitals (i.e., orbitals whose positions are
                   optimized in space) is described. The wave function
                   is optimized using a second-order convergent scheme
                   (the trust-region method), and molecular properties
                   up to second order are calculated analytically. The
                   method is applied to a series of small molecules (HF,
                   H/sub 2/O, NH/sub 3/, CH/sub 4/, CO, H/sub 2/CO, and
                   C/sub 2/H/sub 4/) at the Hartree-Fock level using
                   four different floating basis sets (double zeta,
                   double zeta plus polarization, double zeta plus
                   diffuse, and double zeta plus polarization and
                   diffuse). Geometries are fully optimized, and dipole
                   moments, static polarizabilities, harmonic
                   frequencies, and double-harmonic infrared intensities
                   are calculated at the optimized geometries. The
                   results are compared with those obtained using the
                   corresponding fixed basis sets, and also with the
                   results from a large basis of near-Hartree-Fock
                   quality (6-311++G(3df,3pd)). Floating produces only
                   minor changes in the electronic energy, but other
                   properties are often significantly improved. In
                   particular, properties involving external field
                   variations (dipole moments, polarizabilities, and
                   intensities) converge considerably faster to the
                   Hartree-Fock limit when floating is
                   allowed. Properties calculated using the floating
                   double-zeta basis set augmented with one set of
                   polarization functions and one set of diffuse
                   orbitals are close to the Hartree-Fock limit.},
 summary        = {The calculation of molecular electronic wave
                   functions and properties using floating Gaussian
                   orbitals (i.e., orbitals whose positions are
                   optimized in space) is described. The wave function
                   is optimized using a second-order convergent trust-region
		   method and molecular properties
                   up to second order are calculated analytically. The
                   method is applied to a series of small molecules 
		   at the Hartree-Fock level using four different floating
		   basis sets. Properties calculated using the floating
                   double-zeta basis set augmented with one set of
                   polarization functions and one set of diffuse
                   orbitals are close to the Hartree-Fock limit.}}

@article{Hest69,
 author		= {M. R. Hestenes},
 title		= {Multiplier and gradient methods},
 journal	= JOTA,
 volume		= 4, pages = {303--320}, year = 1969}

@book{Hest80,
 author		= {M. R. Hestenes},
 title		= {Conjugate Direction Methods in Optimization},
 publisher	= SPRINGER, address = SPRINGER-ADDRESS,
 year		= 1980}

@article{HestStie52,
 author		= {M. R. Hestenes and E. Stiefel},
 title		= {Methods of conjugate gradients for solving linear systems},
 journal	= {J. Res. N.B.S.},
 volume		= 49, pages = {409--436}, year = 1952}

@article{High87,
 author		= {N. J. Higham},
 title		= {A survey of condition number estimation for triangular
		   matrices},
 journal	= SIREV,
 volume		= 29, number = 4, pages = {575--596}, year = 1987}

@book{High93,
 author		= {N. J. Higham},
 title		= {Writing for the Mathematical Sciences},
 publisher	= SIAM, address = SIAM-ADDRESS,
 year		= 1993}

@article{High95a,
 author		= {N. J. Higham},
 title		= {Stability of the diagonal pivoting method with partial
		   pivoting},
 journal        = SIMAA,
 volume         = 18, number = 1, pages = {52--65}, year = 1997}

@book{High96,
 author		= {N. J. Higham},
 title		= {Accuracy and Stability of Numerical Algorithms},
 publisher	= SIAM, address = SIAM-ADDRESS,
 year		= 1996}

@techreport{High98,
 author		= {D. J. Higham},
 title		= {Trust Region Algorithms and Timestep Selection},
 institution	= {Department of Mathematics},
 address	= {University of Strathclyde, Glasgow, Scotland},
 type		= {Research Report}, number = 3, year = 1998,
 abstract	= {Unconstrained optimization problems are closely related to
		   systems of ordinary differential equations (ODEs) with
		   gradient structure. In this work, we prove results that
		   apply to both areas. We analyze the convergence properties
		   of a trust region, or Levenberg-Marquadt, algorithm for
		   optimization. The algorithm may also be regarded as a
		   linearized implicit Euler method with adaptive timestep for
		   gradient ODEs. We establish global convergence, and show
		   that the rate of convergence is superlinear, but not
		   quadratic. The precise form of superlinear convergence is
		   exhibited---the ratio of successive displacements from
		   the limit point is bounded above and below by geometrically
		   decreasing sequences. In the gradient ODE context this
		   result contributes to the theory of \emph{gradient
		   stability}. The result also introduces the notion of
		   adapting the timestep in order to control the rate at which
		   equilibrium is approached. A related timestepping algorithm
		   is developed for general ODEs that guarantees fast
		   superlinear local convergence to a stable equilibrium. This
		   algorithm has many applications to ODEs and
		   semi-discretized partial differential equations where a
		   steady state solution is required.},
 summary	= {The close relation between unconstrained optimization and
		   systems of ordinary differential equations (ODEs) with
		   gradient structure is exploited. The convergence properties
		   of a trust region, or Levenberg-Morrison-Marquardt,
		   algorithm are examined. The algorithm may also be regarded
		   as a linearized implicit Euler method with adaptive
		   timestep for gradient ODEs. Global convergence is
		   established and the rate of convergence is superlinear, but
		   not quadratic. The precise form of superlinear convergence
		   is exhibited. In the gradient ODE context this
		   result contributes to the theory of ``gradient stability''.
		   It also introduces the notion of adapting the
		   timestep in order to control the rate at which equilibrium
		   is approached. A related timestepping algorithm
		   for general ODEs  guarantees fast superlinear
		   local convergence to a stable equilibrium. This algorithm
		   has many applications to ODEs and semi-discretized partial
		   differential equations where a steady state solution is
		   required.}}

@article{HighChen98,
 author		= {N. J. Higham and S. Cheng},
 title		= {Modifying the Inertia of Matrices Arising in Optimization},
 journal	= LAA,
 volume		= {275--276}, pages = {261--279}, year = 1998}

@book{HiriLema93,
 author		= {J.-B. Hiriart-Urruty and C. Lemar\'{e}chal},
 title		= {Convex Analysis and Minimization Algorithms. {P}art 1:
		   {F}undamentals},
 publisher	= SPRINGER, address = SPRINGER-ADDRESS,
 year		= 1993}

@book{HiriLema93b,
 author		= {J.-B. Hiriart-Urruty and C. Lemar\'{e}chal},
 title		= {Convex Analysis and Minimization Algorithms. {P}art 2:
		   {A}dvanced Theory and Bundle Methods},
 publisher	= SPRINGER, address = SPRINGER-ADDRESS,
 year		= 1993}

@misc{LeTh97,
 author		= {Le Thi, H. A.},
 title		= {Contribution \`{a} \l'optimisation non convexe et
		   l'optimisation globale},
 howpublished	= {Habilitation thesis, University of Rouen, Rouen, France},
 year		= 1997}

@article{LeTh99,
 author		= {Le Thi, H. A.},
 title          = {An efficient algorithm for globally minimizing a quadratic
                   function under convex quadratic constraints},
 journal        = MP,
 note           = {To appear.}, year = 1999,
 abstract       = {In this paper, we investigate two approaches to minimizing
		   a quadratic form subject to the intersection of finitely
		   many ellipsoids.  The first approach is the
		   d.c. (difference of convex functions) optimization
		   algorithm (DCA) whose main tools are the proximal
		   point algorithm and/or the projection subgradient method
		   in convex optimization.  The second is a branch-and-bound
		   scheme using Lagrangian duality for bounding and
		   ellipsoidal bisection in branching.  The DCA was
		   first introduced by Pham Dinh Tao in 1986 for general
		   d.c. program and later developed by our various work is
		   a local method but, from a good starting point, it often
		   provides a global solution.  This motivates us to combine
		   the DCA and our branch and bound algorithm in order to
		   obtain a good initial point for the DCA and to prove the
		   globality of the DCA.  In both two approaches we
		   attempt to use the ellipsoidal constrained quadratic
		   programs as the main subproblems.  The idea is based upon
		   the fact that these programs can be efficiently solved by
		   the procedure recently proposed by Pham Dinh Tao and Le
		   Thi H. An, which has been shown to be robust and fast to
		   large-scale problems. Several numerical experiments with
		   dimension up to 200 are given which show the effectiveness
		   and the robustness of the DCA and the combined 
		   DCA-branch-and-bound algorithm.}, 
 summary        = {A combination of the DCA (algorithm for the difference of
		   convex functions) and branch-and-bound is developed to
		   globally solve the problem of minimizing a quadratic
		   function subject to a finite set of convex quadratic 
		   constraints. The trust-region subproblem is used as the
		   main subproblem of the new algorithm. Numerical experiments
		   illustrate the proposal.}}

@article{HuanNg94,
 author		= {L. R. Huang and K. F. Ng},
 title		= {2nd-order necessary and sufficient conditions in nonsmooth
		   optimization},
 journal	= MP,
 volume		= 66, number = 3, pages = {379--402}, year = 1994}

@manual{HSL00,
 author		= {{H}arwell {S}ubroutine {L}ibrary},
 title		= {A catalogue of subroutines (release 2000)},
 organization	= HARWELL, address = HARWELL-ADDRESS,
 year		= 2000}


%%% I %%%

@manual{IMSL99,
 author		= {{IMSL}},
 title 		= {Fortran Numerical Library},
 organization	= {Visual Numerics, Inc.}, address = {Houston, Texas, USA},
 year       	= 1999}

@article{Iron70,
 author		= {B. M. Irons},
 title		= {A frontal solution program for finite-element analysis},
 journal	= IJNME,
 volume		= 2, pages = {5--32}, year = 1970}

@article{Iuse91,
 author		= {A. N. Iusem},
 title		= {On the dual convergence and the rate of primal convergence
		   of {B}regman's convex programming method},
 journal	= SIOPT,
 volume		= 1, number = 3, pages = {401--423}, year = 1991}

%%% J %%%

@inproceedings{Jage95,
 author		= {M. Jagersand},
 title		= {Visual servoing using trust region methods and estimation 
                   of the full coupled visual-motor {J}acobian},
 booktitle      = {Proceedings of the IASTED International Conference. 
                   Applications of Control and Robotics},
 publisher      = {IASTED-ACTA Press}, address = {Anaheim, California, USA}, 
 pages          = {105-108}, year = 1995,
 abstract	= {We present an algorithm for visual servoing, capable of 
                   learning the robot kinematics and camera calibration.
                   The approach differs from previous work in that a
                   full coupled Jacobian is estimated online without
                   prior models, and that a trust region method is used,
                   improving stability and convergence of the
                   controller. We present experimental results on the
                   positioning accuracy and convergence of this
                   controller showing an up to 5 fold improvement in
                   repeatability on PUMA 761 and 762 robots and
                   successful estimation of the Jacobian for 3, 6 and 12
                   controlled DOF with highly non-linear transfer
                   functions.},
 summary	= {An algorithm for visual servoing, capable of 
                   learning the robot kinematics and camera calibration,
                   is presented.  The approach differs from previous
                   work in that a full coupled Jacobian is estimated
                   online without prior models, and that a trust region
                   method is used, improving stability and convergence
                   of the controller. Experimental results on the
                   positioning accuracy and convergence of this
                   controller, showing an up to 5 fold improvement in
                   repeatability on PUMA 761 and 762 robots and
                   successful estimation of the Jacobian for 3, 6 and 12
                   controlled DOF with highly non-linear transfer
                   functions, are prsented.}}

@inproceedings{JageFuenNels96,
 author         = {M. Jagersand and O. Fuentes and R. Nelson},
 title          = {Acquiring visual-motor models for precision manipulation 
                   with robot hands},
 editor         = {B. Buxton and R. Cipolla},
 booktitle      = {Computer Vision -- ECCV `96. 4th Eurpean Conference on 
                   Computer Proceedings},
 publisher     	= SPRINGER, address = SPRINGER-ADDRESS,
 volume         = 2, pages = {603--612}, year = 1996,
 abstract       = {Dextrous high degree of freedom (DOF) robotic hands
                   provide versatile motions for fine manipulation of
                   potentially very different objects. However, fine
                   manipulation of an object grasped by a multifinger
                   hand is much more complex than if the object is
                   rigidly attached to a robot arm. Creating an accurate
                   model is difficult if not impossible. We instead
                   propose a combination of two techniques: the use of
                   an approximate estimated motor model, based on the
                   grasp tetrahedron acquired when grasping an object,
                   and the use of visual feedback to achieve accurate
                   fine manipulation. We present a novel active vision
                   based algorithm for visual serving, capable of
                   learning the manipulator kinematics and camera
                   calibration online while executing a manipulation
                   task. The approach differs from previous work in that
                   a full, coupled image Jacobian is estimated online
                   without prior models, and that a trust region control
                   method is used, improving stability and
                   convergence. We present an extensive experimental
                   evaluation of visual model acquisition and visual
                   serving in 3, 4 and 6 DOF.},
 summary        = {Dextrous high degree of freedom (DOF) robotic hands
                   provide versatile motions for fine manipulation of
                   potentially very different objects. However, fine
                   manipulation of an object grasped by a multifinger
                   hand is much more complex than if the object is
                   rigidly attached to a robot arm. Creating an accurate
                   model is difficult if not impossible. We instead
                   propose a combination of two techniques: the use of
                   an approximate estimated motor model, based on the
                   grasp tetrahedron acquired when grasping an object,
                   and the use of visual feedback to achieve accurate
                   fine manipulation. A novel active vision
                   based algorithm for visual serving is presented, capable of
                   learning the manipulator kinematics and camera
                   calibration online while executing a manipulation
                   task. The approach differs from previous work in that
                   a full, coupled image Jacobian is estimated online
                   without prior models, and that a trust-region control
                   method is used, improving stability and
                   convergence. Extensive experimental
                   evaluation of visual model acquisition and visual
                   serving in 3, 4 and 6 DOF. is presented}}

@inproceedings{JageFuenNels97,
 author         = {M. Jagersand and O. Fuentes and R. Nelson},
 title          = {Experimental evaluation of uncalibrated visual servoing 
                   for precision manipulation},
 booktitle      = {Proceedings 1997 IEEE International Conference on Robotics 
                   and Automation}, 
 publisher      = {IEEE}, address = {New York, NY, USA}, 
 volume         = 4, pages = {2874--2880}, year = 1997,
 abstract       = {We present an experimental evaluation of adaptive and
                   non-adaptive visual servoing in 3, 6 and 12 degrees
                   of freedom (DOF), comparing it to traditional joint
                   feedback control. While the purpose of experiments in
                   most other work has been to show that the particular
                   algorithm presented indeed also works in practice, we
                   do not focus on the algorithm but rather on
                   properties important to visual servoing in
                   general. Our main results are: positioning of a 6
                   axis PUMA 762 arm is up to 5 times more precise under
                   visual control than under joint control and positioning
                   of a Utah/MIT dextrous hand is better under visual
                   control than under joint control by a factor of 2 and
                   and a trust-region-based adaptive visual feedback
                   controller is very robust. For m tracked visual
                   features the algorithm can successfully estimate
                   online the m*3 (m>or=3) image Jacobian (J) without
                   any prior information, while carrying out a 3 DOF
                   manipulation task. For 6 and higher DOF manipulation,
                   a rough initial estimate of J is beneficial. We also
                   verified that redundant visual information is
                   valuable. Errors due to imprecise tracking and goal
                   specification were reduced as the number of visual
                   features, m, was increased. Furthermore highly
                   redundant systems allow us to detect outliers in the
                   feature vector and deal with partial occlusion.},
 summary        = {An experimental evaluation of adaptive and
                   non-adaptive visual servoing in 3, 6 and 12 degrees
                   of freedom (DOF) is compared to traditional joint
                   feedback control. The main results are: positioning of a 6
                   axis PUMA 762 arm is up to 5 times more precise under
                   visual control than under joint control and positioning
                   of a Utah/MIT dextrous hand is better under visual
                   control than under joint control by a factor of 2 and
                   and a trust-region-based adaptive visual feedback
                   controller is very robust. For $m$ tracked visual
                   features, the algorithm can successfully estimate
                   online the $3m$ ($m \geq 3$) image Jacobian ($J$) without
                   any prior information, while carrying out a 3 DOF
                   manipulation task. For 6 and higher DOF manipulation,
                   a rough initial estimate of $J$ is beneficial. 
                   Redundant visual information is also shown to be
                   valuable. Errors due to imprecise tracking and goal
                   specification were reduced as the number of visual
                   features, $m$, was increased. Furthermore highly
                   redundant systems allow the detection of outliers in the
                   feature vector and dealing with partial occlusion.}}

@inproceedings{JainMcClSark86,
 author         = {V. K. Jain and T. E. McClellan and T. K. Sarkar},
 title          = {Half-{F}ourier transform and application to radar signals},
 booktitle      = {ICASSP 86 Proceedings. IEEE-IECEJ-ASJ International 
                   Conference on Acoustics, Speech and Signal Processing},
 publisher      = {IEEE}, address = {New York, NY, USA}, 
 volume         = 1, pages = {241--244}, year = {1986},
 abstract       = {The authors discuss the half Fourier transform (HFT)
                   and explore its application to radar-return signals
                   with specular components. It is shown that this
                   transform enables the desired part to be separated
                   from the specular impulsive components. The
                   effectiveness of this technique and the computer
                   program developed is demonstrated by simulation
                   examples. The program uses an optimization package
                   which minimizes a nonlinear sum-of-squares functional
                   with a model trust region strategy.},
 summary        = {The half Fourier transform is discussed
                   and its application to radar-return signals
                   with specular components examined. This
                   transform enables the desired part to be separated
                   from the specular impulsive components. The
		   problem is numerically solved by applying a trust-region
		   algorithm to a nonlinear least-squares formulation.}} 

@article{JaraMack87,
 author         = {H. Jarausch and W. Mackens},
 title          = {Solving large nonlinear systems of equations by an adaptive 
                   condensation process},
 journal        = NUMMATH,
 volume         = 50, number = 6, pages = {633--653}, year = 1987,
 abstract       = {The authors present an algorithm which efficiently
                   solves large nonlinear systems of the form $Au=F(u)$, $u \in
                   \Re^n$ whenever an (iterative) solver '$A^{-1}$' 
                   for the symmetric positive definite matrix $A$ is
                   available and $F'(u)$ is symmetric. Such problems arise
                   from the discretization of nonlinear elliptic partial
                   differential equations. By means of an adaptive
                   decomposition process the authors split the original
                   system into a low dimensional system-to be treated by
                   any sophisticated solver-and a remaining
                   high-dimensional system, which can easily be solved
                   by fixed point iteration. Specifically the authors
                   choose a Newton-type trust region algorithm for the
                   treatment of the small system. They show global
                   convergence under natural assumptions on the
                   nonlinearity. The convergence results typical for
                   trust-region algorithms carry over to the full
                   iteration process. The only large systems to be
                   solved are linear ones with the fixed matrix $A$. Thus
                   existing software for positive definite sparse linear
                   systems can be used.},
 summary        = {The authors present an algorithm which efficiently
                   solves large nonlinear systems of the form $Au=F(u)$, $u \in
                   \Re^n$ whenever an (iterative) solver '$A^{-1}$' 
                   for the symmetric positive definite matrix $A$ is
                   available and $F'(u)$ is symmetric. Such problems arise
                   from the discretization of nonlinear elliptic partial
                   differential equations. By means of an adaptive
                   decomposition process the original
                   system is split into a low-dimensional system-to and a
	    	   remaining high-dimensional system, which can easily
		   be solved by fixed point iteration.
                   A Newton-type trust-region algorithm is chosen for the
                   treatment of the small system. Convergence results typical for
                   trust-region algorithms carry over to the full
                   iteration process.}}
@article{Jarr91,
 author 	= {F. Jarre},
 title  	= {On the convergence of the method of analytic centers when
        	   applied to convex quadratic programs},
 journal 	= MP,
 volume 	= 49, number = 3, pages = {341--358}, year = 1991}
 
@misc{Jarr98,
 author		= {F. Jarre},
 title		= {An {QQP}-Minimization Method for Semidefinite and Smooth
		   nonconvex programs},
 howpublished	= {Presentation at the Optimization 98 Conference, Coimbra},
 year		= 1998,
 abstract	= {Recent international research has focussed on semidefinite
		   programs where the entries of an unknown matrix $X$ need to
		   be chosen in a certain optimal way under the constraint
		   that $X$ be symmetric and positive semi-definite. The
		   present frameworks for solving semidefinite programs allow
		   further convex constraints on the matrix entries. In many
		   real world applications, however, also smooth nonconvex
		   constraints occur. For such problems the standard approach
		   still often used to date is to impose an equality
		   constraint $X=LL^T$ where $L$ is lower tringular. It is not
		   surprising that standard nonlinear optimization software
		   fails for such a formulation; the Cholesky factor $L$ is
		   not unique when $X$ is singular; it lies in a nonlinear
		   nonconvex manifold, and methods based on linearizing the
		   equation $=LL^T$ perform very poorly in this situation. We
		   present an interior-point approach for solving such
		   problems, discuss local convergence properties, and present
		   some preliminary numerical results.},
 summary	= {An interior-point approach is presented for problems where
		   the entries of a positive semidefinite matrix $X$ have to
		   be optimally determined in the presence of non-convex
		   constraints on the entries of $X$. The method combines
		   ideas of a predictor-corrector interior-point method, of
		   the SQP method and of trust-region methods. Some
		   convergence results are given and very preliminary
		   numerical experiments discussed.}}

@article{JarrSaun95,
 author		= {F. Jarre and M. A. Saunders},
 title		= {A practical interior-point method for convex programming},
 journal	= SIOPT,
 volume		= 5, number = 1, pages = {149--171}, year = 1995}

@article{JensAgre86,
 author         = {J. J. A. Jensen and H. Agren},
 title          = {A direct, restricted-step, second-order {MC} {SCF} program 
                   for large scale \emph{ab initio} calculations},
 journal        = {Chemical Physics},
 volume         = 104, number = 2, pages = {229--250}, year = 1986,
 abstract       = {A general purpose MC SCF program with a direct, fully
                   second-order and step-restricted algorithm is
                   presented. The direct character refers to the
                   solution of an MC SCF eigenvalue equation by means of
                   successive linear transformations where the
                   norm-extended hessian matrix is multiplicated onto a
                   trial vector without explicitly constructing the
                   hessian. This allows for applications to large
                   wavefunctions. In the iterative solution of the
                   eigenvalue equation a norm-extended optimization
                   algorithm is utilized in which the number of negative
                   eigenvalues of the Hessian is monitored. The step
                   control is based on the trust region concept and is
                   accomplished by means of a simple modification of the
                   Davidson-Liu simultaneous expansion method (1978) for
                   iterative calculation of an eigenvector. Convergence
                   to the lowest state of a symmetry is thereby
                   guaranteed, and test calculations also show reliable
                   convergence for excited states. The authors outline
                   the theory and describe in detail an efficient
                   implementation, illustrated with sample
                   calculations.},
 summary        = {A general purpose MC SCF program with a direct, fully
                   second-order and step-restricted algorithm is
                   presented. The step control is based on the trust-region
		   concept. Convergence to the lowest state of a symmetry is
                   guaranteed, and test calculations also show reliable
                   convergence for excited states. }}

@article{JensPoly94,
 author		= {D. Jensen and R. Polyak},
 title		= {On the convergence of a modified barrier method for convex
		   programming},
 journal	= {IBM J. Res. Develop.},
 volume		= 38, number = 3, pages = {307--320}, year = 1994}

@techreport{JensPolySchn92,
 author		= {D. Jensen and R. Polyak and R. Schneur},
 title		= {Numerical experience with modified barrier functions method
		   for linear programming},
 institution	= IBMWATSON, address = IBMWATSON-ADDRESS,
 type		= {Research Report}, number = {RC 18415}, year = 1992}

@article{JiKritAbouTont99,
 author		= {X. S. Ji and W. Kritpiphat and A. Aboudheir and 
                   P. Tontiwachwuthikul},
 title		= {Mass transfer parameter estimation using optimization 
                   technique: Case study in {CO}2 absorption with chemical 
                   reaction},
 journal	= {Canadian Journal of Chemical Engineering},
 volume		= 77, number = 1, pages = {69--73}, year = 1999,
 abstract	= {This paper proposes a new approach of applying an 
                   optimization technique to simultaneously determine a
                   physical liquid-film mass transfer coefficient
                   ($k(L)(o)$) and effective interfacial area ($a(v)$) from
                   a pilot plant data. The mass transfer mechanism of
                   the CO2-NaOH system was modeled using the two-film
                   theory to represent the behaviors of packed
                   absorbers. The model presents an overall absorption
                   rate (R-v) as a function of $k(L)(o)$ and $a(v)$. The
                   optimization algorithm used in this study follows a
                   modified Levenberg-Marquardt method with a trust
                   region approach. The R-v predictions from the model
                   are in good agreement with the experimental data,
                   with an average error of 6.5\%.},
 summary	= {A new approach of applying an optimization technique 
                   to simultaneously determine a physical liquid-film
                   mass transfer coefficient ($k(L)(o)$) and effective
                   interfacial area ($a(v)$) from a pilot plant data is
                   considered. The mass transfer mechanism of the
                   CO2-NaOH system is modeled using the two-film theory
                   to represent the behaviors of packed absorbers. The
                   model presents an overall absorption rate (R-v) as a
                   function of $k(L)(o)$ and $a(v)$. The optimization
                   algorithm used in this study follows a modified
                   Levenberg-Morrison-Marquardt method with a trust
                   region approach. The R-v predictions from the model
                   are in good agreement with the experimental data,
                   with an average error of 6.5\%.}}
               
@article{JianQi96,
 author		= {H. Jiang and L. Qi},
 title		= {Globally and superlinearly convergent trust-region
		   algorithms for convex {SC$^1$}-minimization problems and
		   its application to stochastic programs},
 journal	= JOTA,
 volume		= 90, number = 3, pages = {649--669}, year = 1996,
 abstract	= {A function mapping from R(n) to R is called an SC1-function
		   if it is differentiable and its derivative is semismooth. A
		   convex SC1-minimization problem is a convex minimization
		   problem with an SC objective function and linear
		   constraints. Applications of such minimization problems
		   include stochastic quadratic programming and minimax
		   problems. In this paper, we present a globally and
		   superlinearly convergent trust-region algorithm for solving
		   such a problem. Numerical examples are given on the
		   application of this algorithm to stochastic quadratic
		   programs.},
 summary	= {A globally and superlinearly convergent trust-region
		   algorithm for solving SC1 problems is presented.
		   Numerical examples are given on the application of this
		   algorithm to stochastic quadratic programs.}}

@article{JianQi97,
 author		= {H. Jiang and L. Qi},
 title		= {A new nonsmooth equations approach to nonlinear
		   complementarity problems},
 journal	= SICON,
 volume		= 35, number = 1, pages = {178--193}, year = 1997}

@article{JianFukuQiSun98,
 author		= {H. Jiang and M. Fukushima and L. Qi and D. Sun},
 title		= {A trust region method for solving generalized
		   complementarity problems},
 journal	= SIOPT,
 volume		= 8, number = 1, pages = {140--158}, year = 1998,
 abstract	= {Based on a semismooth equation reformulation using
		   Fischer's function, a trust region algorithm is proposed
		   for solving the generalized complementarity problem (GCP).
		   The algorithm uses a generalized Jacobian of the function
		   involved in the semismooth equation and adopts the squared
		   natural residual of the semismooth equation as a merit
		   function. The proposed algorithm is applicable to the
		   nonlinear complementarity problem, because the latter
		   problem is a special case of the GCP. Global convergence
		   and, under a nonsingularity assumption, local Q-superlinear
		   (or quadratic) convergence of the algorithm are
		   established. Moreover, calculation of a generalized
		   Jacobian is discussed and numerical results are presented.},
 summary	= {Based on a semi-smooth equation reformulation using
		   Fischer's function, a trust-region algorithm is proposed
		   for solving the generalized complementarity problem (GCP).
		   It uses a generalized Jacobian of the function
		   involved in the semi-smooth equation and adopts the squared
		   natural residual of the semi-smooth equation as a merit
		   function. Global convergence and, under a nonsingularity
		   assumption, a local Q-superlinear (or quadratic) rate of
		   convergence are established. Calculation of a generalized
		   Jacobian is discussed and numerical results presented.}}

@article{JittOsbo80,
 author		= {K. Jittorntrum and M. R. Osborne},
 title		= {A modified barrier function method with improved rate of
		   convergence for degenerate problems},
 journal	= {Journal of the Australian Mathematical Society (Series B)},
 volume		= 21, pages = {305--329}, year = 1980}

@article{JonsLars90,
 author         = {O. Jonsson and T. Larsson},
 title          = {A note on step-size restrictions in approximation procedures
                   for structural optimization},
 journal        = {Computers and Structures},
 volume         = 37, number = 3, pages = {259--263}, year = 1990,
 abstract       = {Different possibilities are discussed for the
                   restriction of the step size in the well known
                   iterative approximation concept for solving
                   structural optimization problems. Such restrictions
                   might for some problem instances be necessary to
                   stabilize the behaviour of the solution procedure and
                   to ensure convergence. There are two basic means to
                   achieve such a restriction: either by using trust
                   region constraints or by inducting a penalty on
                   getting remote from the approximation point. In
                   structural optimization solution procedures, the
                   first of these possibilities is commonly used. It is
                   demonstrated how a penalty term can be used instead,
                   still making it possible to use the efficient dual
                   concept. Relations to other mathematical programming
                   methods are outlined and a small numerical example is
                   presented.},
 summary        = {Different possibilities are discussed for the
                   restriction of the step size in 
                   iterative approximation methods for
                   structural optimization problems: by using either
		   trust-region constraints or a penalty on
                   the distance from the approximation point. The
                   first approach is commonly used. It is
                   demonstrated how a penalty term can be used instead.}}

@article{JudiPire89,
 author		= {J. J. J\'{u}dice and F. M. Pires},
 title		= {Direct methods for convex quadratic programs subject to box
		   constraints},
 journal	= {Investigaci\'{o}n Operacional},
 volume		= 9, pages = {23--56}, year = 1989}

%%% K %%%

@article{Kani66,
 author		= {S. Kaniel},
 title		= {Estimates for some computational techniques in linear
		   algebra},
 journal	= MC,
 volume		= 20, number = 95, pages = {369--378}, year = 1966}

@article{Kant48,
 author		= {L. Kantorovich},
 title		= {Functional analysis and applied mathematics},
 journal	= {Uspehi Matematicheskih Nauk},
 volume		= 3, pages = {89--185}, year = 1948}

@article{KanzYamaFuku97,
 author		= {Ch. Kanzow and N. Yamashita and M. Fukushima},
 title		= {New {NCP}-Functions and Their Properties},
 journal	= JOTA,
 volume		= 94, number = 1, pages = {115--135}, year = 1997}

@inproceedings{KanzZupk98,
 author		= {Ch. Kanzow and M. Zupke},
 title		= {Inexact Trust-Region Methods for Nonlinear Complementarity
		   Problems},
 crossref	= {FukuQi98}, pages = {211--235},
 abstract	= {In order to solve the nonlinear complementarity problem, we
		   first reformulate it as a nonsmooth system of equations by
		   using a recently introduced NCP-function. We then apply a
		   trust-region-type method to this system of equations. Our
		   trust-region method allows an inexact solution of the
		   trust-region-subproblem. We show that the algorithm is
		   well-defined for a general nonlinear complementarity
		   problem and that it has some nice global and local
		   convergence properties. Numerical results indicate that the
		   new method is quite promising.},
 summary	= {The nonlinear complementarity problem is reformulated as a
		   non-smooth system of equations by using a recently
		   introduced NCP-function. A trust-region-type method is then
		   applied to the resulting system of equations, that allows
		   an inexact solution of the trust-region subproblem. 
		   The algorithm is well-defined for a general
		   nonlinear complementarity problem and  has 
		   global and local convergence properties. Numerical results
		   are discussed.}}

@inproceedings{KariRendWolk94,
 author         = {S. E. Karisch and F. Rendl and H. Wolkowicz},
 title          = {Trust regions and relaxations for the quadratic assignment 
                   problem},
 editor         = {P. M. Pardalos and H. Wolkowicz},
 booktitle      = {Quadratic Assignment and Related Problems. DIMACS Workshop.},
 publisher      = AMS, address = AMS-ADDRESS,
 pages          = {199--219},  year = 1994,
 abstract       = {General quadratic matrix minimization problems, with
                   orthogonal constraints, arise in continuous
                   relaxations for the (discrete) quadratic assignment
                   problem (QAP). Currently, bounds for QAP are obtained
                   by treating the quadratic and linear parts of the
                   objective function, of the relaxations,
                   separately. This paper handles general objectives as
                   one function. The objectives can be both
                   nonhomogeneous and nonconvex. The constraints are
                   orthogonal or Loewner partial order (positive
                   semidefinite) constraints. Comparisons are made to
                   standard trust region subproblems. Numerical results
                   are obtained using a parametric eigenvalue
                   technique.},
 summary        = {General quadratic matrix minimization problems, with
                   orthogonal constraints, arise in continuous
                   relaxations for the (discrete) quadratic assignment
                   problem (QAP). Currently, bounds for QAP are obtained
                   by treating the quadratic and linear parts of the
                   objective function, of the relaxations,
                   separately. It is shown how to handle general objectives as
                   one function. The objectives can be both
                   non-homogeneous and non-convex. The constraints are
                   orthogonal or Loewner partial order (positive
                   semidefinite) constraints. Comparisons are made with
                   standard trust-region subproblems. Numerical results
                   are obtained using a parametric eigenvalue
                   technique.}}

@article{Karm84,
 author		= {N. Karmarkar},
 title		= {A new polynomial-time algorithm for linear programming},
 journal	= {Combinatorica},
 volume		= 4, pages = {373--395}, year = 1984}

@mastersthesis{Karu39,
 author		= {W. Karush},
 title		= {Minima of functions of several variables with inequalities
		   as side conditions},
 school		= {Department of Mathematics},
 address	= {University of Chicago, Illinois, USA},
 year		= 1939}

@article{Kauf00,
 author         = {L. Kaufman},
 title          = {A reduced storage, quasi-{N}ewton trust region approach to
                   function optimization},
 journal        = SIOPT,
 volume         = 10, number = 1, pages = {56--69}, year = 2000,
 abstract       = {In this paper we consider several algorithms for reducing
                   the storage when using a quasi-Newton method in a dogleg
                   trust region setting for minimizing functions of many
                   variables.  Secant methods  require 0 (n 2 ) locations to
                   store an approximate Hessian and 0 (n 2 ) operations per
                   iteration when minimizing  a function of n variables. This
                   storage requirement  becomes  worrisome  when n becomes
                   large.  Our  algorithms  use  a  BFGS update and require
                   kn storage and 4kn + 0 (k 2 ) operations per iteration,
                   but may require more iterations than the standard
                   trust region techniques.  Typically k is between 10 and
                   100.  Our  dogleg  trust region  strategies  involve
                   expressions  with  matrix  products  with both the inverse
                   of this Hessian and with the Hessian itself.  Our techniques
                   for updating expressions  for  the  Hessian  and  its 
                   inverse  can  be  used  to  improve the  performance  of 
                   line search, limited memory algorithms.},
 summary        = {A limited-memory quasi-Newton BFGS algorithm for
                   unconstrained optimization is described that uses a dogleg
                   trust-region scheme. This technique uses products both with
                   the approximate Hessian and its inverse.}}

@article{KeHan95a,
 author		= {X. Ke and J. Han},
 title		= {A class of nonmonotone trust region algorithms for
		   constrained optimizations},
 journal	= CSB,
 volume		= 40, number = 16, pages = {1321--1324}, year = 1995,
 abstract	= {In this note, we consider the following constrained
		   optimization problem (CQP), where $f: R''. R$ is
		   continuously differentiable function on a closed convex set
		   $\Omega$. For the constrained optimization problem (CQP), a
		   class of nonmonotone trust region algorithms is proposed in
		   sec. 1. In sec.2, the global convergence of this class of
		   algorithms is proved. In sec. 3, some results about the
		   Cauchy point are provided. The nonmonotone technique in
		   this algorithm differs from those in existing nonmonotone
		   algorithms, i.e. nonmonotone algorithms with linear search
		   for unconstrained and constrained optimizations , and the
		   nonmonotone trust region algorithm for unconstrained
		   optimization.},
 summary	= {The constrained optimization problem of minimizing a
		   continuously differentiable function over a closed convex
		   set is considered. A class of globally convergent 
		   non-monotone trust-region algorithms is proposed for this
		   problem.}}

@article{KeHan95b,
 author		= {X. Ke and J. Han},
 title		= {A nonmonotone trust region algorithm for equality
		   constrained optimization},
 journal	= {Science in China Series A-Mathematics Physics Astronomy and
		   Technological Sciences},
 volume		= 38, number = 6, pages = {683--695}, year = 1995,
 abstract	= {A trust region algorithm for equality constrained
		   optimization is proposed, which is a nonmonotone one in a
		   certain sense. The augmented Lagrangian function is used as
		   a merit function. Under certain conditions, the global
		   convergenece theorems of the algorithm are proved.},
 summary	= {A non-monotone trust region algorithm is proposed for the
		   minimization of smooth functions subject to nonlinear
		   equality constraints. It handles feasibility as
		   \citebb{CeliDennTapi85} and allows non-monotonicity in the
		   augmented Lagrangian which is used as a merit function.}}


@article{KeHan96,
 author		= {X. Ke and J. Han},
 title		= {A nonmonotone trust region algorithm for unconstrained
		   nonsmooth optimization},
 journal	= CSB,
 volume		= 41, number = 3, pages = {197--201}, year = 1996,
 summary	= {A non-monotone trust-region method is presented for the
		   solution of non-smooth unconstrained problems. This
		   algorithm uses the concept of ``iteration functions'' of
		   \icitebb{QiSun94}. Global convergence to a Dini stationary
		   point is proved.}}

@inproceedings{KehtWinMull87,
 author         = {N. Kehtarnavaz and M. Z. Win and N. Mullani},
 title          = {Estimation of diastole to systole changes from cardiac 
                   {PET} images},
 booktitle      = {Proceedings of the Ninth Annual Conference of the IEEE 
                   Engineering in Medicine and Biology Society},
 publisher      = {IEEE}, address = {New York, NY, USA}, 
 volume         = 2, pages = {850--851}, year = {1987},
 abstract       = {The changes in the myocardium thickness, left
                   ventricle diameter and tracer activity between
                   diastole and systole are estimated from cardiac
                   positron-emission-tomography (PET) images. A
                   comparative study has been carried out between the
                   widely used international mathematical subroutine
                   library (IMSL) and the model-trust-region (MTR)
                   parameter estimation algorithm. It has been shown
                   that the MTR algorithm converges regardless of the
                   initial parameter values (IPV) chosen. To reduce the
                   number of iterations, a preprocessor has been
                   developed to provide close IPV to the true parameter
                   values (TPV). Myocardial, left ventricular and tracer
                   activity changes are plotted as functions of bipolar
                   angle. The graphs can be used as a diagnostic tool
                   for abnormal heart conditions.},
 summary        = {The changes in the myocardium thickness, left
                   ventricle diameter and tracer activity between
                   diastole and systole are estimated from cardiac
                   positron-emission-tomography (PET) images. A
                   comparative study is carried out between the IMSL
                   mathematical subroutine library and the model-trust-region
		   (MTR) parameter estimation algorithm. It is shown
                   that the MTR algorithm converges regardless of the
                   initial parameter values chosen. To reduce the
                   number of iterations, a preprocessor has been
                   developed to provide better starting values.
		   The method is used as a diagnostic tool
                   for abnormal heart conditions.}}


@article{Kell73,
 author 	= {E. L. Keller},
 title  	= {The general quadratic programming problem},
 journal 	= MP,
 volume 	= 5, number = 3, pages = {311--337}, year = 1973}

@article{KellSach87,
 author		= {C. T. Kelley and E. W. Sachs},
 title		= {Quasi-{N}ewton methods and unconstrained optimal control
		   problems},
 journal	= SICON,
 volume		= 25, number = 6, pages = {1503--1517}, year = 1987}

@article{KellSach99,
 author		= {C. T. Kelley and E. W. Sachs},
 title		= {A trust region method for parabolic boundary control
		   problems},
 journal        = SIOPT,
 volume         = 9, number = 4, pages = {1064--1081}, year = 1999,
 abstract	= {In this paper, we develop a trust region algorithm for
		   constrained parabolic boundary control problems. The method
		   is a projected form of the Steihaug trust-region CG method
		   with a smoothing step added at each iteration to improve
		   performance in the global phase and provide
		   mesh-independent sup-norm convergence in the terminal
		   phase.},
 summary	= {A trust-region algorithm for constrained parabolic boundary
		   control problems is developed. The method is a projected
		   form of the Steihaug-Toint  method with a
		   smoothing step added at each iteration to improve
		   performance in the global phase and provide
		   mesh-independent sup-norm convergence in the terminal
		   phase.}}

@article{KellKeye98,
 author		= {C. T. Kelley and D. E. Keyes},
 title		= {Convergence analysis of pseudo-transient continuation},
 journal	= SINUM,
 volume		= 35, number = 2, pages = {508--523}, year = 1998,
 abstract	= {Pseudo-transient continuation is a well-known and
		   physically motivated technique for computation of
		   steady-state solutions of time-dependent partial
		   differential equations. Standard globalization strategies
		   such as line search or trust-region methods often stagnate
		   at local minima. Pseudo-transient continuation succeeds in
		   many of these cases by taking advantage of the underlying
		   PDE structure of the problem. Though widely employed, the
		   convergence of this scheme is rarely discussed. In this
		   paper we prove convergence for a generic form of
		   pseudo-transient continuation and illustrate it with two
		   practical strategies.},
 summary	= {Pseudo-transient continuation is a well-known and
		   physically motivated technique for computation of
		   steady-state solutions of time-dependent partial
		   differential equations. Standard globalization strategies
		   such as linesearch or trust-region methods often stagnate
		   at local minima. Pseudo-transient continuation succeeds in
		   many of these cases by taking advantage of the underlying
		   PDE structure of the problem. Convergence
		   for a generic form of pseudo-transient continuation is
		   proved, and illustrated with two practical strategies.}}

@article{KeLiuXu96,
 author		= {X. Ke and G. Liu and D. Xu},
 title		= {A nonmonotone trust region algorithm for unconstrained
		   nonsmooth optimization},
 journal	= CSB,
 volume		= 41, number = 3, pages = {197--201}, year = 1996,
 summary	= {A globally convergent trust-region algorithm is proposed
		   for unconstrained minimization of locally Lipschitzian
		   functions, that generalizes the approach of
		   \citebb{QiSun94}  by allowing a non-monotone
		   sequence of objective function values.}} 

@techreport{KhalByrdSchn99,
 author		= {H. F. Khalfan and R. H. Byrd and R. B. Schnabel},
 title		= {Retaining Convergence Properties of Trust Region Methods
		   Without Extra Gradient Evaluations},
 institution 	= {Department of Mathematics and Computer Science,
		   University of Colorado},
 address	= {Boulder, Colorado, USA},
 year		= 1999,
 abstract	= {Several recent computational studies have shown that
		   trust-region quasi-Newton methods using the SR1, PSB,
		   and BFGS updates are effective methods for solving
		   unconstrained optimization problems.  In addition, the
		   analyses in \citebb{Powe75} and \citebb{ByrdKhalSchn96} 
		   demonstrate strong convergence properties for some
		   trust-region quasi-Newton methods.  A computational
		   disadvantage of the methods analyzed in these papers, for
		   which the strongest convergence properties among
		   trust-region quasi-Newton methods have been shown, is that
		   the update at rejected points requires a gradient
		   evaluation that would not otherwise be made.  In this 
		   paper, we propose a modification of the PSB method that
		   uses only the function value at rejected points to make the
		   update at those points.  We then show how to modify
		   Powell's analysis of the PSB method to prove the same 
		   $q$-superlinear convergence result for the new method.
		   Finally, we discuss the issues and difficulties involved in
		   extending this approach to trust region methods using
		   updates in the Broyden class, such as the BFGS, SR1 and
		   DFP.},  
 summary	= {A modification of a trust-region method  based on the PSB
		   quasi-Newton update is proposed method that uses only the
		   function value at rejected points to make the update at
		   those points.  The same $q$-superlinear convergence result
		   as for the original algorithm holds for the new method.}}


@inproceedings{Kiwi89,
 author		= {K. C. Kiwiel},
 title		= {A survey of bundle methods for non-differentiable
		   optimization},
 crossref	= {IriTana89}, pages = {263-282}}

@article{Kiwi89b,
 author         = {K. C. Kiwiel},
 title          = {An ellipsoid trust region bundle method for nonsmooth 
                   convex minimization},
 journal        = SICON,
 volume         = 27, number = 4, pages = {737--757}, year = 1989,
 abstract       = {This paper presents a bundle method of descent for 
                   minimizing a convex (possibly nonsmooth) function f
                   of several variables. At each iteration the algorithm
                   finds a trial point by minimizing a polyhedral model
                   of f subject to an ellipsoid trust region
                   constraint. The quadratic matrix of the constraint,
                   which is updated as in the ellipsoid method, is
                   intended to serve as a generalized 'Hessian' to
                   account for 'second-order' effects, thus enabling
                   faster convergence. The interpretation of generalized
                   Hessians is largely heuristic, since so far this
                   notion has been made precise by J.L. Goffin only in
                   the solution of linear inequalities. Global
                   convergence of the method is established and
                   numerical results are given.}, 
 summary        = {A bundle method of descent for 
                   minimizing a convex (possibly non-smooth) function
                   of several variables. At each iteration the algorithm
                   finds a trial point by minimizing a polyhedral model
                   subject to an ellipsoid trust-region
                   constraint. The quadratic matrix of the constraint,
                   which is updated as in the ellipsoid method, is
                   interpreted as a generalized 'Hessian' to
                   account for 'second-order' effects, thus enabling
                   faster convergence. Global
                   convergence of the method is established and
                   numerical results are given.}}


@article{Kiwi96,
 author		= {K. C. Kiwiel},
 title		= {Restricted step and {L}evenberg-{M}arquardt techniques in
		   proximal Bundle Methods for nonconvex nondifferentiable
		   optimization},
 journal	= SIOPT,
 volume		= 6, number = 1, pages = {227--249}, year = 1996,
 abstract	= {Two methods are given for minimizing locally Lipschitzian
		   upper semidifferentiable functions. They employ extensions
		   of restricted step (trust region) and Levenberg-Marquardt
		   techniques that are widely used in other contexts.
		   Extensions to linearly constrained optimization are
		   discussed. Preliminary numerical experience is reported.},
 summary	= {Two methods are given for minimizing locally Lipschitzian
		   upper semidifferentiable functions. They employ extensions
		   of restricted step (trust region) and
		   Levenberg-Morrison-Marquardt techniques. Extensions to 
		   linearly constrained optimization are discussed. Preliminary
		   numerical experience is reported.}}

@phdthesis{Knot83,
 author		= {O. Knoth},
 title		= {{M}arquardt-\"{a}hnliche {V}erfahren zur {M}inimierung
		   nichtlinearer {F}unktionen},
 school		= {Martin-Luther University},
 address	= {Halle-Wittenberg, Germany},
 year		= 1983,
 note		= {(in German)},
 summary	= {Accumulation points of the
		   trust-region Newton method for unconstrained optimization
		   are proved to satisfy second order optimality
		   conditions. The use of negative curvature in a
		   ``projected'' Marquardt algorithm is also introduced.
		   Finally, the characterization of local minima for the
		   $\ell_2$ trust-region subproblem is considered together
		   with the use of an exact penalty function for this
		   subproblem.}}

@book{Knut73,
 author	 	= {D. E. Knuth},
 title   	= {The Art of Computer Programming, Volume 3,
		   Sorting and Searching},
 publisher 	= ADW, address = ADW-ADDRESS,
 year    	= 1973}

@article{Knut76,
 author		= {D. E. Knuth},
 title		= {Big {O}micron and {B}ig {O}mega and {B}ig {T}heta},
 journal	= {ACM SIGACT News},
 volume		= 8, number = 2, pages = {18--24}, year = 1976}

@article{Koji93,
 author		= {F. Kojima},
 title		= {Back-propagation learning using the trust region algorithm
		   and application to nondestructive testing in applied
		   electromagnetics},
 journal	= {International Journal of Applied Electromagnetics in
		   Materials},
 volume		= 4, number = 7, pages = {27--33}, year = 1993,
 abstract	= {An artificial neural network is applied by nondestructive
		   inspections in aerospace materials. The use of an
		   artificial neural network is presented for classifying
		   testing data as corresponding to sample materials with
		   defect and without defect. The back-propagation learning
		   for a multi-layer feed-forward neural network is applied to
		   this classification. The trust region method is adopted to
		   the back-propagation learning problem. Results of numerical
		   tests are summarized.},
 summary	= {An artificial neural network is applied by non-destructive
		   inspections in aerospace materials. The back-propagation
		   learning for a multi-layer feed-forward neural network is
		   applied to the resulting classification problem. The
		   trust-region method is adapted to the back-propagation
		   learning problem. Numerical tests are discussed.}}

@inproceedings{KojiKawa93,
 author         = {F. Kojima and H. Kawaguchi},
 title          = {Backpropagation learning algorithm for nondestructive 
                   testing by thermal imager (aerospace materials)},
 booktitle      = {IJCNN '93-Nagoya. Proceedings of 1993 International Joint 
                   Conference on Neural Networks},
 publisher      = {IEEE}, address = {New York, NY, USA}, 
 volume         = 1, pages = {955--958}, year = 1993,
 abstract       = {An artificial neural network is applied to
                   nondestructive inspections using thermal imager. The
                   use of an artificial neural network is presented for
                   classifying test data as corresponding to bonded and
                   disbonded regions in sample materials. The
                   backpropagation learning for a multi-layer
                   feedforward neural network is applied to this
                   classification. The trust region method is adopted to
                   the backpropagation learning problem. Results of
                   numerical tests are summarized.},
 summary        = {An artificial neural network is applied to
                   non-destructive inspections using thermal imager. The
                   use of an artificial neural network is presented for
                   classifying test data as corresponding to bonded and
                   disbonded regions in sample materials. The
                   backpropagation learning for a multi-layer
                   feedforward neural network is applied to this
                   classification. The trust-region method is adopted to
                   the backpropagation learning problem. Numerical results
                   are summarized.}}


@inproceedings{KrukWolk98,
 author		= {S. Kruk and H. Wolkowicz},
 title		= {{SQ}${}^2${P}, Sequential Quadratic Constrained Quadratic
		   Programming},
 crossref	= {Yuan98}, pages = {177--204},
 abstract	= {We follow the popular approach for unconstrained
		   minimization, i.e. we develop a local quadratic model at a
		   current approximate minimizer in conjunction with a trust
		   region. We then minimize this local model in order to find
		   the next approximate minimizer. Asymptotically, finding the
		   local minimizer of the quadratic model is equivalent to
		   applying Newton's method to the stationarity condition. For
		   constrained problems, the local quadratic model corresponds
		   to minimizing a quadratic expression of the objective
		   subject to quadratic approximations of the constraints
		   (Q${}^2$P), with an additional trust region. This quadratic
		   model is intractable in general and is usually handled by
		   using linear approximations of the constraints and
		   modifying the Hessian of the objective function using the
		   Hessian of the Lagrangian, i.e. a SQP approach. Instead, we
		   solve the Lagrangian relaxation of Q${}^2$P using
		   semi-definite programming. We develop this framework and
		   present an example which illustrates the advantages over
		   the standard SQP approach.},
 summary	= {An algorithm is proposed for constrained nonlinear
		   programming in which a quadratic model of the
		   objective function is minimized, at each iteration, subject
		   to quadratic approximations of the constraints (Q${}^2$P)
		   and an additional trust region. As this subproblem is in
		   general intractable, the Lagrangian relaxation of Q${}^2$P
		   is instead solved using semi-definite programming. An
		   example illustrates the advantages over the standard SQP
		   approach.}}

@inproceedings{KuhnTuck51,
 author		= {H. W. Kuhn and A. W. Tucker},
 title		= {Nonlinear Programming},
 booktitle	= {Proceedings of the second Berkeley symposium on
		   mathematical statistics and probability},
 editor		= {J. Neyman},
 publisher	= {University of Berkeley Press}, address = {California, USA},
 year		= 1951}

@article{KwokKamaWats85,
 author		= {H. H. Kwok and M. P. Kamat and L. T. Watson},
 title		= {Location of stable and unstable equilibrium-configurations
		   using a model trust region quasi-{N}ewton method and
		   tunnelling},
 journal	= {Computers and Structures},
 volume		= 21, number = 5, pages = {909--916}, year = 1985,
 abstract	= {A hybrid method for locating multipole equilibrium
		   configurations has been proposed recently. The hybrid
		   method combined the efficiency of a quasi-Newton method
		   capable of locating stable and unstable equilibrium
		   solutions with a robust homotopy method capable of tracking
		   equilibrium paths, with turning points and exploiting
		   sparsity of the Jacobian matrix at the same time. A
		   quasi-Newton method in conjunction with a deflation
		   technique is proposed here as an alternative to the hybrid
		   method. The proposed method not only exploits sparsity and
		   symmetry, but also represents an improvement in efficiency},
 summary	= {The conjunction of a quasi-Newton method with a deflation
		   technique is proposed as an alternative to the hybrid
		   method for locating multipole equilibrium configurations.
		   The proposed method not only exploits sparsity and
		   symmetry, but also represents an improvement in efficiency.
		   It uses a double dogleg globalization strategy.}}

%%% L %%%

@article{LaleNocePlan98,
 author		= {M. Lalee and J. Nocedal and T. D. Plantenga},
 title		= {On the implementation of an algorithm for large-scale
		   equality constrained optimization},
 journal	= SIOPT,
 volume		= 8, number = 3, pages = {682--706}, year = 1998,
 abstract	= {This paper describes a software implementation of Byrd and
		   \citebb{Omoj89}'s trust-region algorithm for solving
		   nonlinear equality constrained optimization problems. The
		   code is designed for the efficient solution of large
		   problems and provides the user with a variety of linear
		   algebra techniques for solving the subproblems occurring in
		   the algorithm. Second derivative information can be used,
		   but when it is not available, limited memory quasi-Newton
		   approximations are made. The performance of the code is
		   studied using a set of difficult test problems from the
		   {\sf CUTE} collection.},
 summary	= {A software implementation of Byrd and \citebb{Omoj89}'s
		   trust-region algorithm for nonlinear equality constrained
		   optimization is described. The
		   code is designed for the efficient solution of large
		   problems and provides the user with a variety of linear
		   algebra techniques for solving the subproblems occurring in
		   the algorithm. Second derivative information can be used,
		   as well as limited memory quasi-Newton approximations. The
		   performance of the code is studied using a set of difficult
		   test problems from the {\sf CUTE} collection.}}

@book{LancTism85,
 author		= {P. Lancaster and M. Tismenetsky},
 title		= {The Theory of Matrices},
 publisher	= AP, address = AP-ADDRESS,
 edition	= {second}, year = 1985}

@article{Lanc50,
 author		= {C. Lanczos},
 title		= {An iteration method for the solution of the eigenvalue
		   problem of linear differential and integral operators},
 journal	= {Journal of research of the National Bureau of Standards B},
 volume		= 45, pages = {225--280}, year = 1950}

@article{Lann97,
 author		= {A. Lannes},
 title		= {Phase-closure imaging in algebraic graph theory: a new
		   class of phase-calibration algorithms},
 journal	= {Journal of the Optical Society of America A-Optics Image
		   Science and Vision},
 volume		= 15, number = 2, pages = {419--429}, year = 1997,
 abstract	= {A new class of phase-calibration algorithms is presented.
		   The originality of these algorithms, as well as their
		   efficiency, results from certain particular structures, the
		   analysis of which calls on algebraic graph theory. The
		   corresponding optimization process, which is based on the
		   principle of the trust-region methods, proves to be well
		   suited to these structures. The main message that emerges
		   from the study is very clear: the traditional notions of
		   phase closure imaging can be understood and refined in a
		   wider framework. The implications of this research
		   therefore concern all the fields in which the notion of
		   phase closure plays a key role: weak-phase imaging in
		   optical interferometry, radio imaging, remote sensing by
		   aperture synthesis, etc.},
 summary	= {A class of phase-calibration algorithms is presented.
		   Their originality, as well as their efficiency, results
		   from certain particular structures, the analysis of which
		   calls on algebraic graph theory. The corresponding
		   optimization process, which is based on the principle of
		   the trust-region methods, proves to be well suited to these
		   structures. The main result is that the traditional notions
		   of phase closure imaging can be understood and refined in a
		   wider framework. This has implications in all the fields
		   where the notion of phase closure plays a key role, such as
		   weak-phase imaging in optical interferometry, radio imaging
		   and remote sensing by aperture synthesis.}}

@article{Lann98,
 author		= {A. Lannes},
 title		= {Weak-phase imaging in optical interferometry},
 journal	= {Journal of the Optical Society of America A-Optics Image
		   Science and Vision},
 volume		= 15, number = 4, pages = {811--824}, year = 1998,
 abstract	= {The first imaging devices of optical interferometry are
		   likely to be of weak phase, typically: a set of
		   three-element arrays independently observing the same
		   object. The study of their imaging capabilities refers to
		   appropriate optimization methods, which essentially address
		   the self-calibration process and its stability. A general
		   survey of these techniques is given, and it is shown, in
		   particular, how the related algorithms can be used for
		   examining the imaging capabilities of weak-phase
		   interferometric devices. The phase-calibration algorithm
		   involved in the self-calibration cycles is based on the
		   principle underlying the trust-region methods. It benefits
		   from certain remarkable properties, the analysis of which
		   appeals to algebraic graph theory. The Fourier synthesis
		   operation, which is also involved in these cycles, is
		   performed by means of WIPE, a methodology recently
		   introduced in radio imaging and optical interferometry.
		   (WIPE is reminiscent Of CLEAN, a widely used technique in
		   astronomy). In the related theoretical framework the
		   stability of the image-reconstruction process is controlled
		   by considering certain elements of the singular-value
		   decomposition of the derivative of the self- calibration
		   operator. For example, the largest singular value of this
		   derivative, which depends on the interferometric
		   configuration and on the object thus imaged, provides a key
		   indication of the observational limits of these
		   experimental devices.},
 summary	= {The first imaging devices of optical interferometry are
		   likely to be of weak phase, typically: a set of
		   three-element arrays independently observing the same
		   object. The study of their imaging capabilities refers to
		   appropriate optimization methods, which essentially address
		   the self-calibration process and its stability. A general
		   survey of these techniques is given, and it is shown, in
		   particular, how the related algorithms can be used for
		   examining the imaging capabilities of weak-phase
		   interferometric devices. The phase-calibration algorithm
		   involved in the self-calibration cycles is based on the
		   principle underlying the trust-region methods. Its
		   remarkable properties are shown using
		   the algebraic graph theory. The Fourier synthesis
		   operation, which is also involved in these cycles, is
		   performed by means of WIPE, a methodology 
		   introduced in radio imaging and optical interferometry.
		   In the related theoretical framework the
		   stability of the image-reconstruction process is controlled
		   by considering certain elements of the singular-value
		   decomposition of the derivative of the self- calibration
		   operator. For example, the largest singular value of this
		   derivative, which depends on the interferometric
		   configuration and on the object thus imaged, provides a key
		   indication of the observational limits of these
		   experimental devices.}}

@article{LasdPlumYu95,
 author         = {L. S. Lasdon and J. Plummer and G. Yu},
 title          = {Primal-dual and primal interior point algorithms for 
                   general nonlinear programs},
 journal        = ORSAC,
 volume         = 7, number = 3, pages = {321--332}, year = 1995,
 abstract       = {An interior point algorithm for general nonlinear
                   programs is presented. Inequality constraints are
                   converted to equalities with slack variables. All
                   bounds are handled with a barrier term in the
                   objective. The Kuhn-Tucker system of the resulting
                   equality constrained barrier problem is solved
                   directly by Newton's method. Primal-dual, primal, and
                   primal-dual with trust region variants are developed
                   and evaluated. An implementation which utilizes the
                   true Lagrangian Hessian and exploits Jacobian and
                   Hessian sparsity is described. Computational results
                   are presented and discussed.},
 summary        = {An interior point algorithm for general nonlinear
                   programs is presented. Inequality constraints are
                   converted to equalities with slack variables. All
                   bounds are handled with a barrier term in the
                   objective. The Kuhn-Tucker system of the resulting
                   equality constrained barrier problem is solved
                   directly by Newton's method. Primal-dual, primal, and
                   primal-dual with trust-region variants are developed
                   and evaluated. An implementation which utilizes the
                   true Lagrangian Hessian and exploits Jacobian and
                   Hessian sparsity is described. Computational results
                   are presented and discussed.}}


@book{LawsHans74,
 author		= {C. L. Lawson and R. J. Hanson},
 title		= {Solving Least Squares Problems},
 publisher	= PH, address = PH-ADDRESS,
 year		= 1974,
 note           = {Reprinted as \emph{Classics in Applied Mathematics 15}, SIAM,
		   Philadelphia, USA, 1995}}

@misc{LeibSach99,
 author         = {F. Leibfritz and E. W. Sachs},
 title          = {Optimal Static Output Feedback Design using a Trust Region
                   Interior Point Method},
 howpublished   = {Presentation at the First Workshop on Nonlinear
                   Optimization ``Interior-Point and Filter Methods'',
                   Coimbra, Portugal},
 year           = 1999,
 abstract       = {We consider the problem of designing feedback control laws
                   when a complete set of state variables is not available. 
                   The resulting nonlinear and nonconvex matrix optimization
                   problem including SDP-constraints for determining the
                   optimal feedback gain will be solved by a trust region
                   interior point approach.  The algorithm will be discussed
                   in some details.  Finally, using test examples from optimal
                   output feedback design we demonstrate the usefulness of
                   this approach numerically.},
 summary        = {The problem of designing feedback control laws is considered
                   when a complete set of state variables is not available.
                   The resulting nonlinear and non-convex matrix optimization
                   problem including semi-definiteness constraints for
                   determining the optimal feedback gain is solved by a
                   trust-region interior-point approach. Test examples from
                   optimal output feedback design numerically demonstrate the
                   usefulness of the approach.}}

@inproceedings{LemaZowe94,
 author		= {C. Lemar\'{e}chal and J. Zowe},
 title		= {A condensed introduction to bundle methods in nonsmooth
		   optimizations},
 crossref	= {Sped94}, pages = {357--382}}

@article{Lesc91,
 author		= {M. Lescrenier},
 title		= {Convergence of trust region algorithms for optimization
		   with bounds when strict complementarity does not hold},
 journal	= SINUM,
 volume		= 28, number = 2, pages = {476--495}, year = 1991,
 abstract	= {\citebb{ConnGoulToin88a} have proposed a class of trust
		   region algorithms for minimizing nonlinear functions whose
		   variables are subjected to simple bound constraints. In
		   their convergence analysis, they show that if the strict
		   complementarity condition holds, the considered algorithms
		   reduce to an unconstrained calculation after finitely many
		   iterations, allowing fast asymptotic rates of convergence.
		   This paper analyzes the behaviour of these iterative
		   processes in the case where the strict complementarity
		   condition is violated. It is proved that inexact Newton
		   methods lead to superlinear or quadratic rates of
		   convergence, even if the set of active bounds at the
		   solution is not entirely detected. Practical criteria for
		   stopping the inner iterations of the algorithms are
		   deduced, ensuring these rates of convergence.},
 summary	= {The behaviour of the trust-region algorithms of
		   \citebb{ConnGoulToin88a} for optimization with simple
		   bounds is analyzed in the case where the strict
		   complementarity condition is violated. It is proved that
		   inexact Newton methods lead to superlinear or quadratic
		   rates of convergence, even if the set of active bounds at
		   the solution is not entirely detected. Practical criteria
		   for stopping the inner iterations of the algorithms are
		   deduced.}}

@book{LeTaGlow89,
 author		= {Le Tallec, P. and Glowinski, R.},
 title		= {Augmented Lagrangian and Operator-Splitting Methods in
		   Nonlinear Mechanics},
 publisher	= SIAM, address = SIAM-ADDRESS,
 year		= 1989}

@article{Leve44,
 author		= {K. Levenberg},
 title		= {A Method For The Solution Of Certain Problems In Least
		   Squares},
 journal	= {Quarterly Journal on Applied Mathematics},
 volume		= 2, pages = {164--168}, year = 1944,
 summary	= {The standard method for solving least-squares problems
		   which leads to nonlinear normal equations depends on a
		   reduction of the residuals to linear form by first-order
		   Taylor approximations. taken about a trial solution for the
		   parameters. If the usual least-squares procedure with these
		   linear approximations yields new values for the parameters
		   which are not sufficiently close to the trial values, the
		   neglect of second and higher order terms may invalidate the
		   process. This difficulty may be alleviated by limiting the
		   absolute values of the parameters and to simultaneously
		   minimize the sum of squares of the approximating residuals
		   under these ``damped'' conditions.}}

@article{LeviPoly66,
 author		= {E. S. Levitin and B. T. Polyak},
 title		= {Constrained minimization problems},
 journal	= {U.S.S.R. Comput. Math. Math. Phys.},
 volume		= 6, pages = {1--50}, year = 1966}
 
@misc{Lewi96,
 author		= {R. M. Lewis},
 title		= {A trust region framework for managing approximation models
		   in engineering optimization},
 howpublished	= {AIAA paper 96-4101, presented at the Sixth AIAA/NASA/ISSMO
		   Symposium on Multidisplinary Analysis and Design, Bellevue,
		   Washington},
 year		= 1996,
 summary	= {Non-quadratic models are proposed for the trust-region
		   minimization of expensive functions from engineering
		   applications.}}

@techreport{Li93,
 author		= {Y. Li},
 title		= {Centering, trust region, reflective techniques for
		   nonlinear minimization subject to bounds},
 institution	= CS-CORNELL, address = CORNELL-ADDRESS,
 number		= {TR93-1385}, year = 1993,
 abstract	= {Bound-constrained nonlinear minimization problems occur
		   frequently in practice. Most existing methods belong to an
		   active set type which can be slow for large scale problems.
		   Recently, we proposed a new approach (\citebb{ColeLi94},
		   \citebb{ColeLi96} \citebb{ColeLi96b}) which generates
		   iterates within the strictly feasible region. The method in
		   \citebb{ColeLi96b} is a trust region type and, unlike the
		   existing trust region method for bound-constrained
		   problems, the conditions for its strong convergence
		   properties are consistent with algorithm implementation. A
		   reflective technique can be included in the method. In this
		   paper, we motivate techniques which are important for our
		   new approach. Numerical experience on some medium size
		   problems is included.},
 summary	= {Motivation is  provided for techniques which are important
		   for the method of \citebb{ColeLi96b}. Numerical experience
		   on some medium size problems is included.}}

@techreport{Li94a,
 author		= {Y. Li},
 title		= {A Trust-Region and Affine Scaling Method for Nonlinearly
		   Constrained Minimization},
 institution	= CS-CORNELL, address = CORNELL-ADDRESS,
 number		= {TR94-1463}, year = 1994,
 abstract	= {A nonlinearly constrained minimization problem can be
		   solved by the exact penalty approach involving
		   nondifferentiable functions $\sum_i|c_i(x)|$ and $\sum_i
		   \max(0,c_i(x))$. In this paper, a trust region approach
		   based on a 2-norm subproblem is proposed for solving a
		   nonlinear $\ell_1$ problem. The (quadratic) approximation
		   and the trust region subproblem are defined using affine
		   scaling techniques. Explicit sufficient decrease conditions
		   based on the approximations are suggested for obtaining a
		   limit point satisfying complementarity, Kuhn-Tucker
		   conditions, and the second order necessary conditions. The
		   global convergence of the method is presented in
		   \citebb{Li94b}.},
 summary	= {A trust-region approach based on a $\ell_2$ norm subproblem
		   is proposed for solving a nonlinear $\ell_1$ problem. The
		   (quadratic) approximation and the trust-region subproblem
		   are defined using affine scaling techniques. Explicit
		   sufficient decrease conditions based on the approximations
		   are suggested for obtaining a limit point satisfying
		   complementarity, Kuhn-Tucker conditions, and the second
		   order necessary conditions.}}

@techreport{Li94b,
 author		= {Y. Li},
 title		= {On Global Convergence of a Trust-Region and Affine Scaling
		   Method for Nonlinearly Constrained Minimization},
 institution	= CS-CORNELL, address = CORNELL-ADDRESS,
 number		= {TR94-1462}, year = 1994,
 abstract	= {A nonlinearly constrained minimization problem can be
		   solved by the exact penalty approach involving
		   non-differentiable functions $\sum_i|c_i(x)|$ and $\sum_i
		   \max(0,c_i(x))$. In \citebb{Li94a}, a trust region affine
		   scaling approach based on a 2-norm subproblem is proposed
		   for solving a nonlinear $\ell_1$ problem. The (quadratic)
		   approximation and the trust region subproblem are defined
		   using affine scaling techniques. Explicit sufficient
		   decrease conditions based on the approximations are
		   proposed to obtain a limit point satisfying
		   complementarity, Kuhn-Tucker conditions, and the second
		   order necessary conditions. In this paper, we present the
		   global convergence properties of this new approach.},
 summary	= {Global convergence properties of the method by
		   \citebb{Li94a} are presented.}}

@article{Li96,
 author		= {W. Li},
 title		= {Differentiable Piecewise Quadratic Exact Penalty Functions
		   for Quadratic Programs With Simple Bound Constraints},
 journal	= SIOPT,
 volume		= 6, number = 2, pages = {299--315}, year = 1996}

@inproceedings{Li97,
 author		= {W. Li},
 title		= {A Merit Function and a {N}ewton-Type Method for Symmetric
		   Linear Complementarity Problems},
 crossref	= {FerrPang97}, pages = {181--203}}

@article{LianXu97,
 author		= {X. Liang and C. Xu},
 title		= {A trust region algorithm for bound constrained minimization},
 journal	= {Optimization},
 volume		= 41, number = 3, pages = {279--289}, year = 1997,
 abstract	= {A trust region algorithm is proposed for box constrained
		   nonlinear optimization. At each step of the algorithm a
		   quadratic model problem in box is minimized. Global
		   convergence and quadratic convergence rate to a strong
		   local minimizer are given. Computational results are
		   presented to show the efficiency of the algorithm.},
 summary	= {A trust region algorithm is proposed for box constrained
		   nonlinear optimization. At each step of the algorithm a
		   quadratic model problem is minimized in a box. Global
		   convergence and quadratic convergence rate to a strong
		   local minimizer are given. Computational results are
		   presented to show the efficiency of the algorithm.}}

@techreport{Liao95,
 author		= {A. Liao},
 title		= {Solving unconstrained discrete-time
		   optimal-control-problems using trust method},
 institution	= ACRI-CORNELL, address = CORNELL-ADDRESS,
 number		= {CTC95TR230}, year = 1995,
 abstract	= {trust-region method for a class of large-scale minimization
		   problems, the unconstrained discrete-time optimal control
		   (DTOC) problems, is considered. We show that the
		   trust-region subproblem can be solved within an acceptable
		   accuracy without forming the Hessian explicitly. The new
		   approach is based on the inverse power method for
		   eigenvalue problem and possesses the ability to handle the
		   hard case. Our proposed approach leads to more efficient
		   algorithms for DTOC problems.},
 summary	= {A trust-region method is considered for solving
		   unconstrained discrete-time optimal control (DTOC)
		   problems, in which the trust-region subproblem can be
		   solved within an acceptable accuracy without forming the
		   Hessian explicitly. The approach is based on the inverse
		   power method for eigenvalue problem and can handle the hard
		   case. It leads to more efficient algorithms for DTOC
		   problems.}}

@article{Liao97,
 author		= {A. Liao},
 title		= {Some efficient algorithms for unconstrained discrete-time
		   optimal control problems},
 journal	= {Applied Mathematics and Computation},
 volume		= 87, number = {2-3}, pages = {175--198}, year = 1997,
 abstract	= {The differential dynamic programming algorithm (DDP) and
		   the stagewise Newton procedure are two typical examples of
		   efficient local procedures for discrete-time optimal
		   control (DTOC) problems. It is desirable to generalize
		   these local procedures to globally convergent methods. One
		   successful globalization was recently proposed by
		   \citebb{ColeLiao95} which combines the trust region idea
		   with \citebb{Pant88}'s stagewise Newton procedure. In this
		   paper we propose several algorithms for DTOC problems which
		   combine a modified ''dogleg'' algorithm with DDP or
		   Pantoja's Newton procedure. These algorithms possess
		   advantages of both the dogleg algorithm and the DDP or the
		   stagewise procedure, i.e., they have strong global and
		   local convergence properties yet remain economical.
		   Numerical results are presented to compare these algorithms
		   and the Coleman-Liao algorithm.},
 summary	= {Several algorithms for discrete time optimal control
		   problems are proposed, which combine a modified dogleg
		   algorithm with the differential dynamic programming method
		   or \citebb{Pant88}'s Newton procedure. These algorithms
		   possess advantages of both the dogleg algorithm and the DDP
		   or the stagewise procedure, i.e., they have strong global
		   and local convergence properties yet remain economical.
		   Numerical results are presented to compare these algorithms
		   and the \citebb{ColeLiao95} algorithm.}}

@article{LinMore99,
 author		= {C. Lin and J. J. Mor\'{e}},
 title		= {{N}ewton's Method for Large Bound-Constrained Optimization
		   Problems},
 journal        = SIOPT,
 volume         = 9, number = 4, pages = {1100--1127}, year = 1999,
 abstract	= {We analyze a trust region version of Newton's method for
		   bound-constrained problems. Our approach relies on the
		   geometry of the feasible set, not on the particular
		   representation in terms of constraints. The convergence
		   theory holds for linearly-constrained problems, and yields
		   global and superlinear convergence theory without assuming
		   neither strict complementarity nor linear independence of
		   the active constraints. We also show that the convergence
		   theory leads to an efficient implementation for large
		   bound-constrained problems.},
 summary	= {A trust region version of Newton's method for
		   bound-constrained problems is proposed, that relies on the
		   geometry of the feasible set, not on the particular
		   representation in terms of constraints. The convergence
		   theory holds for linearly-constrained problems, and yields
		   global and superlinear convergence theory without assuming
		   neither strict complementarity nor linear independence of
		   the active constraints. The theory also leads to an
		   efficient implementation for large bound-constrained
		   problems.}}
%institution	= ANL, address = ANL-ADDRESS,
%number		= {MCS-P724-0898}, year = 1998,

@article{LiuHanWang98,
 author		= {G. Liu and J. Han and S. Wang},
 title		= {A trust region algorithm for bilevel programming problems},
 journal	= {Chinese Science Bulletin},
 volume		= 43, number = 10, pages = {820--824}, year = 1998,
 abstract	= {A trust region algorithm is proposed for solving bilevel
		   programming problems where the lower level programming
		   problem is a strongly convex programming problem with
		   linear constraints. This algorithm is based on a trust
		   region algorithm for nonsmooth unconstrained optimization
		   problems, and its global convergence is also proved.},
 summary	= {A trust region algorithm is proposed for solving bilevel
		   programming problems where the lower level programming
		   problem is a strongly convex programming problem with
		   linear constraints. This algorithm is based on a trust
		   region algorithm for non-smooth unconstrained optimization
		   problems, and its global convergence is also proved.}}

@article{LiuNoce89,
 author		= {D. Liu and J. Nocedal},
 title		= {On the limited memory {BFGS} method for large scale
		   optimization},
 journal	= MPB,
 volume		= 45, number = 3, pages = {503--528}, year = 1989}

@misc{LiuYuan98,
 author         = {X. Liu and Y. Yuan},
 title          = {A robust trust-region algorithm for solving general
                   nonlinear programming problems},
 howpublished	= {Presentation at the International Conference on Nonlinear
                   Programming and Variational Inequalities, Hong Kong},
 year		= 1998,
 abstract       = {The trust-region approach has been extended to solving
                   nonlinear constrained optimization.  Most of these
                   extensions consider only equality constraints and require
                   strong global regularity assumptions.  In this report, a
                   trust-region algorithm for solving general nonlinear
                   programming is presented, which solves a trust-region
                   subproblem and a quadratic programming trust-region
                   subproblem at each iteration.  The algorithm is similar
                   to the methods presented by \citebb{Burk92} and 
                   \citebb{Yuan95}.  For the equality constrained case, our
                   algorithm is similar to the methods of 
                   \citebb{DennElAlMaci97} and \citebb{DennVice97}.  A new
                   penalty parameter updating procedure is introduced.  Under
                   very milds conditions, the global convergence results are
                   proved.  Some local convergence results are also proved. 
                   The preliminary numerical results show that our algorithm
                   is comparable to {\tt VF02AD}.},
 summary        = {A trust-region methods for general constrained optimization
                   is discussed, that uses a composite step technique.  The 
                   normal step is obtained by solving an ordinary trust-region
                   subproblem, while the tangential step results from a
                   trust-region constrained quadratic program.  The method has
                   similarities with those of \citebb{Burk92}, \citebb{Yuan95},
                   \citebb{DennElAlMaci97} and \citebb{DennVice97}, but
                   features a new updating rule for the penalty parameter.
                   It is globally convergent.  Numerical results indicate that
                   its efficiency is comparable to that of {\tt VF02AD}.}}

@article{LiSwet93,
 author		= {W. Li and J. Swetits},
 title		= {A {N}ewton Method for Convex Regression, Data Smoothing,
		   and Quadratic Programming with Bounded Constraints},
 journal	= SIOPT,
 volume		= 3, number = 3, pages = {466--488}, year = 1993}

@article{Loot69,
 author		= {F. A. Lootsma},
 title		= {Hessian matrices of penalty functions for solving
		   constrained optimization problems},
 journal	= {Philips Research Reports},
 volume		= 24, pages = {322--331}, year = 1969}

@article{Lots84,
 author		= {P. L\"{o}tstedt},
 title		= {Solving the minimal least squares problem subject to bounds
		   on the variables},
 journal	= BIT,
 volume		= 24, pages = {206--224}, year = 1984}

@article{LuciGuoWang93,
 author		= {A. Lucia and X. Z. Guo and X. Wang},
 title		= {Process Simulation in the complex-domain},
 journal	= {Aiche Journal},
 volume		= 39, number = 3, pages = {461--470}, year = 1993,
 abstract	= {The asymptotic behavior of fixed-point methods in the
		   complex domain is studied. Both direct substitution and
		   Newton's method exhibit stable periodic and aperiodic
		   behavior from real- or complex-valued starting points.
		   Moreover, multiple stable periodic orbits can exist for
		   direct substitution. Traditional trust region (or dogleg)
		   methods, on the other hand, often terminate at singular
		   points, which correspond to nonzero-valued saddlepoints in
		   the least-squares function that can be arbitrarily far from
		   a solution. Furthermore, the basins of attraction of these
		   singular points are usually dispersed throughout the basin
		   boundaries in the complex domain, clearly illustrating that
		   singular points (via the dogleg strategy) also attract
		   either real- or complex-valued starting points. In light of
		   this, an extension of the dogleg strategy to the complex
		   domain, based on a simple norm-reducing, singular point
		   perturbation, is proposed. This extended trust region
		   method removes all forms of nonconvergent behavior and
		   always terminates at a fixed point, even from critical
		   point (worst-case) initial values. Many numerical results
		   and geometric illustrations using chemical process
		   simulation examples are presented.},
 summary	= {The asymptotic behaviour of fixed-point methods in the
		   complex domain is studied. Both direct substitution and
		   Newton's method exhibit stable periodic and aperiodic
		   behaviour from real- or complex-valued starting points.
		   Moreover, multiple stable periodic orbits can exist for
		   direct substitution. Traditional trust-region (or dogleg)
		   methods, on the other hand, often terminate at singular
		   points, which correspond to non-zero-valued saddlepoints in
		   the least-squares function that can be arbitrarily far from
		   a solution. Furthermore, the basins of attraction of these
		   singular points are usually dispersed throughout the basin
		   boundaries in the complex domain, clearly illustrating that
		   singular points (via the dogleg strategy) also attract
		   either real- or complex-valued starting points. In this
		   light, an extension of the dogleg strategy to the complex
		   domain, based on a simple norm-reducing, singular point
		   perturbation, is proposed. This extended trust-region
		   method always terminates at a fixed point, even from
		   critical point (worst-case) initial values. Numerical
		   results and geometric illustrations using chemical process
		   simulation examples are presented.}}

@article{LuciXu90,
 author         = {A. Lucia and J. Xu},
 title          = {Chemical process optimization using {N}ewton-like methods},
 journal        = {Computers and Chemical Engineering},
 volume         = 14, number = 2, pages = {119--138}, year = 1990,
 abstract       = {Various interrelated issues that effect the
                   reliability and efficiency of Newton-like methods for
                   chemical process optimization are studied. An
                   algorithm for solving large, sparse quadratic
                   programming (QP) problems that is based on an active
                   set strategy and a symmetric, indefinite
                   factorization is presented. The QP algorithm is fast
                   and reliable. A simple asymmetric trust region method
                   is proposed for improving the reliability of
                   successive QP methods. Ill-defined QP subproblems are
                   avoided by adjusting the size of the trust region in
                   an automatic way. Finally, it is shown that reliable
                   initial values of the unknown variables and
                   multipliers can be generated automatically using
                   generic problem information, short-cut techniques and
                   simulation tools. Many relevant numerical results and
                   illustrations are presented.},
 summary        = {An  algorithm for solving large, sparse quadratic
                   programming (QP) problems that is based on an active
                   set strategy and a symmetric, indefinite
                   factorization is presented. A simple asymmetric 
                   trust-region method is proposed for improving the
                   reliability of successive QP methods. Ill-defined QP
                   subproblems are avoided by adjusting the size of the
                   trust region in an automatic way. Finally, it is shown
		   that reliable initial values of the unknown variables
		   and multipliers can be generated automatically using
                   generic problem information, short-cut techniques and
                   simulation tools. Relevant numerical results and
                   illustrations are presented.}}


@article{LuciXu94,
 author         = {A. Lucia and J. Xu},
 title          = {Methods of successive quadratic programming},
 journal        = {Computers and Chemical Engineering},
 volume         = 18, pages = {S211-215}, year = 1994,
 abstract       = {The occurrence of nondescent directions in successive
                   quadratic programming is studied. It is shown that
                   simple chemical process examples can be constructed
                   that exhibit nondescent as a consequence of the
                   projected indefiniteness of the Hessian matrix of the
                   Lagrangian function. Moreover, in situations where
                   multiple Kuhn-Tucker points for the quadratic
                   programming sub-problems exist, the global optimum
                   need not necessarily provide a direction of
                   descent. Thus search for a global solution is
                   unjustified. To circumvent these difficulties, a
                   linear programming-based trust region method is
                   proposed to guarantee descent for any arbitrary merit
                   function, provided such a direction exists. Geometric
                   illustrations are used to elucidate the main ideas.},
 summary        = {Simple chemical process examples are constructed
                   that exhibit non-descent in successive
                   quadratic programming as a consequence of the
                   projected indefiniteness of the Hessian matrix of the
                   Lagrangian function. Moreover, in situations where
                   multiple Kuhn-Tucker points for the quadratic
                   programming sub-problems exist, the global optimum
                   need not necessarily provide a direction of
                   descent. Thus search for a global solution is
                   unjustified. To circumvent these difficulties, a
                   linear programming-based trust region method is
                   proposed to guarantee descent for any arbitrary merit
                   function, provided such a direction exists. Geometric
                   illustrations are used to elucidate the main ideas.}}

@article{Luci92,
 author		= {S. Lucidi},
 title		= {New Results on a Continuously Differentiable Exact Penalty
		   Function},
 journal	= SIOPT,
 volume		= 2, number = 4, pages = {558--574}, year = 1992}

@techreport{LuciPalaRoma94,
 author		= {S. Lucidi and L. Palagi and M. Roma},
 title		= {Quadratic programs with a quadratic constraint:
		   characterisation of {KKT} points and equivalence with an
		   unconstrained problem},
 institution	= {University of Rome "La Sapienza"}, address = {Rome},
 type		= {Technical Report}, number = {24-94}, year = 1994,
 abstract	= {In this paper, we consider the problem of minimizing a
		   quadratic function with a quadratic constraint. We point
		   out some new properties of the problem. In particular, in
		   the first part of the paper, we show that (i) the number of
		   values of the objective function at KKT points is bounded
		   by $3n+1$ where $n$ is the dimension of the problem; (ii)
		   given a KKT point that is not global minimizer, it is easy
		   to find a ``better'' feasible point; (iii) strict
		   complementarity holds at the local-nonglobal minimum point.
		   In the second part, we show that the original constrained
		   problem is equivalent to the unconstrained minimization of
		   a piecewise quartic merit function. Using the unconstrained
		   formulation, we give, in the nonconvex case, a new second
		   order necessary condition for global minimum points. A
		   possible algorithmic application of the preceding results
		   is briefly outlined.},
 summary	= {The technical report associated with
		   \citebb{LuciPalaRoma98}, but containing more technical
		   detail.}}

@article{LuciPalaRoma98,
 author		= {S. Lucidi and L. Palagi and M. Roma},
 title		= {On some properties of quadratic programs with a convex
		   quadratic constraint},
 journal	= SIOPT,
 volume		= 8, number = 1, pages = {105--123}, year = 1998,
 abstract	= {In this paper, we consider the problem of minimizing a
		   (possibly nonconvex) quadratic function with a quadratic
		   constraint. We point out some new properties of the
		   problem. In particular, in the first part of the paper, we
		   show that (i) given a KKT point that is not global
		   minimizer, it is easy to find a ``better'' feasible point;
		   (ii) strict complementarity holds at the local-nonglobal
		   minimum point. In the second part, we show that the
		   original constrained problem is equivalent to the
		   unconstrained minimization of a piecewise quartic merit
		   function. Using the unconstrained formulation, we give, in
		   the nonconvex case, a new second order necessary condition
		   for global minimum points. In the third part, algorithmic
		   applications of the preceding results are briefly outlined,
		   and some preliminary numerical experiments are reported.},
 summary	= {The problem of minimizing a non-convex quadratic function
		   with a quadratic constraint is considered, and
		   properties of the problem identified. In particular, (i)
		   given a KKT point that is not global minimizer, it is easy
		   to find a ``better'' feasible point; and (ii) strict
		   complementarity holds at the local-non-global minimum point.
		   It is also shown that the original constrained problem is
		   equivalent to the unconstrained minimization of a piecewise
		   quartic merit function. Using this
		   formulation, a second order necessary condition for global
		   minimum points is given in the non-convex case. Algorithmic
		   applications are outlined, and preliminary numerical
		   experiments reported.}}

@article{LuciXuLayn96,
 author		= {A. Lucia and J. Xu and K. M. Layn},
 title		= {Nonconvex Process Optimization},
 journal	= {Computers and Chemical Engineering},
 volume		= 20, number = 12, pages = {1375--1398}, year = 1996,
 abstract	= {Difficulties associated with nonconvexity in successive
		   quadratic programming (SPQ) methods are studied. It is
		   shown that projected indefiniteness of the Hessian matrix
		   of the Lagrangian function can (i) place restrictions on
		   the order in which inequalities can be added or deleted
		   from the active set, (ii) generate redundant active sets
		   whose resolution is nontrivial, (iii) give rise to
		   quadratic programming (QP) subproblems that have multiple
		   Kuhn-Tucker points, and (iv) produce nondescent directions
		   in the SQP method that can lead to failure. Related issues
		   concerned with the use of feasible or infeasible starting
		   points for the iterative quadratic programs, forcing
		   positive definiteness to ensure convexity and using
		   iterative methods to solve the linear Kuhn-Tucker
		   conditions associated with the QP subproblems are also
		   studied. A new active set strategy that (i) monitors
		   projected indefiniteness to guide the addition of
		   constraints to the active set, (ii) permits line searching
		   for negative values of the line search parameter, and (iii)
		   does not necessarily delete active constraints with
		   incorrect Kuhn-Tucker multipliers is proposed. Constraint
		   redundancy is circumvented using an algorithm that
		   identifies all nontrivial redundant subsets of smallest
		   size and determines which, if any, exchanges are justified.
		   Nondescent in the NLP's is resolved using a linear
		   programming (LP)-based trust region method that guarantees
		   descent regardless of merit function. It is also shown that
		   there is no justification for using feasible starting
		   points at the QP level of the calculations, that forcing
		   positive definiteness to ensure convexity can cause
		   termination at undesired solutions, and that the use of
		   iterative methods to solve the linear Kuhn-Tucker equations
		   for the QP's can cause a deterioration in numerical
		   performance. Many small chemical process examples are used
		   to highlight difficulties so that geometric illustrations
		   can be used while heat exchange network design and
		   distillation operations examples are used to show that
		   these same difficulties carry over the larger problems.},
 summary	= {Difficulties associated with non-convexity in successive
		   quadratic programming (SPQ) methods are studied. It is
		   shown that projected indefiniteness of the Hessian matrix
		   of the Lagrangian function can (i) place restrictions on
		   the order in which inequalities can be added or deleted
		   from the active set, (ii) generate redundant active sets
		   whose resolution is non-trivial, (iii) give rise to
		   quadratic programming (QP) subproblems that have multiple
		   Kuhn-Tucker points, and (iv) produce non-descent directions
		   in the SQP method that can lead to failure. Related issues
		   concerned with the use of feasible or infeasible starting
		   points for the iterative quadratic programs, forcing
		   positive definiteness to ensure convexity and using
		   iterative methods to solve the linear Kuhn-Tucker
		   conditions associated with the QP subproblems are also
		   studied. An active set strategy that (i) monitors
		   projected indefiniteness to guide the addition of
		   constraints to the active set, (ii) permits line searching
		   for negative values of the linesearch parameter, and (iii)
		   does not necessarily delete active constraints with
		   incorrect Kuhn-Tucker multipliers is proposed. Constraint
		   redundancy is circumvented using an algorithm that
		   identifies all non-trivial redundant subsets of smallest
		   size and determines which, if any, exchanges are justified.
		   Non-descent in the NLP's is resolved using a linear
		   programming (LP)-based trust-region method that guarantees
		   descent regardless of merit function. It is also shown that
		   there is no justification for using feasible starting
		   points at the QP level of the calculations, that forcing
		   positive definiteness to ensure convexity can cause
		   termination at undesired solutions, and that the use of
		   iterative methods to solve the linear Kuhn-Tucker equations
		   for the QP's can cause a deterioration in numerical
		   performance. Many small chemical process examples are used
		   to highlight difficulties so that geometric illustrations
		   can be used while heat exchange network design and
		   distillation operations examples are used to show that
		   these same difficulties carry over the larger problems.}}

@book{Luen69,
 author		= {D. G. Luenberger},
 title		= {Optimization by Vector Space Methods},
 publisher	= WILEY, address = WILEY-ADDRESS,
 year		= 1969}

@book{Luen84,
 author		= {D. G. Luenberger},
 title		= {Linear and Nonlinear Programming},
 publisher	= ADW, address = ADW-ADDRESS,
 edition	= {second}, year = 1984}

@article{Luks93,
 author		= {L. Luk\v{s}an},
 title		= {Inexact Trust Region Method for Large Sparse Nonlinear
		   Least-Squares},
 journal	= {Kybernetica},
 volume		= 29, number = 4, pages = {305--324}, year = 1993,
 abstract	= {The main purpose of this paper is to show that linear least
		   squares methods based on bidiagonalization, namely the LSQR
		   algorithm, can be used for generation of trust region path.
		   This property is a basis for an inexact trust region method
		   which uses the LSQR algorithm for direction determination.
		   This method is very efficient for large sparse nonlinear
		   least squares as it is supported by numerical experiments.},
 summary	= {It is shown that linear least-squares methods based on the
		   LSQR algorithm can be used for generation of trust-region
		   path. This property is a basis for an inexact trust-region
		   method. Numerical experiments suggest that this
		   method is efficient for large sparse nonlinear
		   least-squares.}}

@article{Luks94,
 author		= {L. Luk\v{s}an},
 title		= {Inexact Trust Region Method for Large Sparse Systems of
		   Nonlinear Equations},
 journal	= {Journal of Optimization Theory and Applications},
 volume		= 81, number = 3, pages = {569--590}, year = 1994,
 abstract	= {The main purpose of this paper is to prove the global
		   convergence of the new trust region method based on the
		   smoothed CGS algorithm. This method is surprisingly
		   convenient for the numerical solution of large sparse
		   systems of nonlinear equations, as is demonstrated by
		   numerical experiments. A modification of the proposed trust
		   region method does not use matrices, so it can be used for
		   large dense systems of nonlinear equations.},
 summary	= {The global convergence of the a trust-region method based
		   on the smoothed CGS algorithm is proved. Numerical
		   experiments indicate that the method is surprisingly
		   convenient for the numerical solution of large sparse
		   systems of nonlinear equations. A modification of the
		   method does not use matrices, and can be used for large
		   dense systems of nonlinear equations.}}

@article{Luks96a,
 author		= {L. Luk\v{s}an},
 title		= {Hybrid methods for large sparse nonlinear least-squares},
 journal	= JOTA,
 volume		= 89, number = 3, pages = {575--595}, year = 1996,
 abstract	= {Hybrid methods are developed for improving the Gauss-Newton
		   method in the case of large residual or ill-conditioned
		   nonlinear least-square problems. These methods are used
		   usually in a form suitable for dense problems. But some
		   standard approaches are unsuitable, and some new
		   possibilities appear in the sparse case. We propose
		   efficient hybrid methods for various representations of the
		   sparse problems. After describing the basic ideas that help
		   deriving new hybrid methods, we are concerned with
		   designing hybrid methods for sparse Jacobian and sparse
		   Hessian representations of the least-square problems. The
		   efficiency of hybrid methods is demonstrated by extensive
		   numerical experiments.},
 summary	= {Hybrid methods are developed for improving the Gauss-Newton
		   method in the case of large residual or ill-conditioned
		   nonlinear least-square problems. Hybrid methods for sparse
                   Jacobian and sparse Hessian representations of the 
                   least-square problems are considered. The efficiency of
                   these methods is illustrated by extensive numerical
                   experiments. }}

@article{Luks96b,
 author		= {L. Luk\v{s}an},
 title		= {Combined Trust Region Methods for Nonlinear Least-Squares},
 journal	= {Kybernetica},
 volume		= 32, number = 2, pages = {121--138}, year = 1996,
 abstract	= {Trust region realizations of the Gauss-Newton method are
		   commonly used for obtaining solution of nonlinear least
		   squares problems. We propose three efficient algorithms
		   which improve standard trust region techniques : multiple
		   dog-leg strategy for dense problems and two combined
		   conjugate gradient Lanczos strategies for sparse problem.
		   Efficiency of these methods is demonstrated by extensive
		   numerical experiments.},
 summary	= {Trust-region realizations of the Gauss-Newton method are
		   commonly used for obtaining solution of nonlinear
		   least-squares problems. Three algorithms which improve
		   standard trust-region techniques are proposed, comprising a
		   multiple dog-leg strategy for dense problems and two
		   combined conjugate-gradient Lanczos strategies for sparse
		   problem. Efficiency of these methods is illustrated by
		   extensive numerical experiments.}}

@article{Luks96c,
 author		= {L. Luk\v{s}an},
 title		= {Efficient Trust Region Method for nonlinear least-squares},
 journal	= {Kybernetica},
 volume		= 32, number = 2, pages = {105--120}, year = 1996,
 abstract	= {The main purpose of this paper is to show that suitable
		   transformations and decompositions lead to an efficient
		   trust region method that uses one decomposition in each
		   iteration only. Convergence properties of the trust region
		   method with optimal locally constrained step (OLCS) that
		   uses more than one decomposition in each iteration and,
		   therefore, that needs a longer time for obtaining results.
		   This fact is demonstrated by numerical experiments.},
 summary	= {Suitable transformations and decompositions 
		   lead to an efficient trust-region method that uses a single
		   factorization at each iteration. This is compared to the
		   optimal locally constrained step that uses more than one
		   decomposition per iteration. Numerical experiments suggest
		   that the former approach is more efficient.}}

@article{LuksVlce96,
 author		= {L. Luk\v{s}an and J. Vl\v{c}ek},
 title		= {Optimization of dynamical-systems},
 journal	= {Kybernetica},
 volume		= 32, number = 5, pages = {465--482}, year = 1996,
 abstract	= {Consider an optimization problem where the objective
		   function is an integral containing the solution of a system
		   of ordinary differential equations. Suppose we have
		   efficient optimization methods available as well as
		   efficient methods for initial value problems for ordinary
		   differential equations. The main purpose of this paper is
		   to show how these methods can be efficiently applied to a
		   considered problem. First, the general procedures for the
		   evaluation of gradients and Hessian matrices are described.
		   Furthermore, the new efficient Gauss-Newton-like
		   approximation of the Hessian matrix is derived for the
		   special case when the objective function is an integral of
		   squares. This approximation is used for deriving the
		   Gauss-Newton-like trust region method, with which global
		   and superlinear convergence properties are proved. Finally
		   several optimization methods are proposed and computational
		   experiments illustrating their efficiency are shown.},
 summary	= {Optimization problems where the objective function is an
		   integral containing the solution of a system of ordinary
		   differential equations are considered. It is shown that
		   optimization methods and methods for initial value problems
		   for ordinary differential equations can be efficiently
		   combined. General procedures for the evaluation of
		   gradients and Hessian matrices are described. An
		   efficient Gauss-Newton-like approximation of the Hessian
		   matrix is derived for the special case when the objective
		   function is an integral of squares. This approximation is
		   used to derive a Gauss-Newton-like trust-region method, for
		   which global and superlinear convergence properties are
		   proved. Finally several methods are proposed and
		   illustrated by computational experiments.}}

@article{LuksVlce97,
 author		= {L. Luk\v{s}an and J. Vl\v{c}ek},
 title		= {Truncated trust region methods based on preconditioned
		   iterative subalgorithms for large sparse systems of
		   nonlinear equations},
 journal	= JOTA,
 volume		= 95, number = 3, pages = {637--658}, year = 1997,
 abstract	= {This paper is devoted to globally convergent methods for
		   solving large sparse systems of nonlinear equations with an
		   inexact approximation of the Jacobian matrix. These methods
		   include difference versions of the Newton method and
		   various quasi-Newton methods. We propose a class of trust
		   region methods together with a proof of their global
		   convergence and describe an implementable globally
		   convergent algorithm which can be used as a realization of
		   these methods. Considerable attention is concentrated on
		   the application of conjugate gradient-type iterative
		   methods to the solution of linear subproblems. We prove
		   that both the GMRES and the smoothed CGS
		   well-preconditioned methods can be used for the
		   construction of globally convergent trust region methods.
		   The efficiency of our algorithm is demonstrated
		   computationally by using a large collection of sparse test
		   problems.},
 summary	= {Globally convergent methods for solving large sparse
		   systems of nonlinear equations with an inexact
		   approximation of the Jacobian matrix are studied. These
		   methods include difference versions of the Newton method
		   and various quasi-Newton methods. A class of trust region
		   methods is proposed together with a proof of their global
		   convergence and an implementable globally convergent
		   algorithm described which can be used as a realization of
		   these methods. Emphasis is put on the application of
		   conjugate gradient-type iterative methods to the solution
		   of linear subproblems. We prove that both the GMRES and the
		   smoothed CGS well-preconditioned methods can be used for
		   the construction of globally convergent trust region
		   methods. The efficiency of our algorithm is demonstrated
		   computationally by using a large collection of sparse test
		   problems.}}

@article{LuoTsen93,
 author		= {Z. Q. Luo and P. Tseng},
 title		= {Error bounds and convergence analysis of feasible direction
		   methods: a general approach},
 journal	= AOR,
 volume		= 46, pages = {157--178}, year = 1993}

@inproceedings{LuoTsen97,
 author		= {Z. Q. Luo and P. Tseng},
 title		= {A New Class of Merit Functions for the Nonlinear
		   Complemetarity Problem},
 crossref	= {FerrPang97}, pages = {204--225}}

@article{LyleSzul94,
 author		= {S. Lyle and M. Szularz},
 title		= {Local Minima of the Trust Region Problem},
 journal	= JOTA,
 volume		= 80, number = 1, pages = {117--134}, year = 1994,
 abstract	= {We consider the minimization of a quadratic form $z^TVz +
		   2z^Tq$ subject to the two-norm constraint parallel to
		   $||z||=\alpha$. The problem received considerable attention
		   in the literature, notably due to its applications to a
		   class of trust region methods in nonlinear optimization.
		   While the previous studies were concerned with just the
		   global minimum of the problem, we investigate the existence
		   of all local minima. The problem is approached via the dual
		   Lagrangian, and the necessary and sufficient conditions for
		   the existence of all local minima are derived. We also
		   examine the suitability of the conventional numerical
		   techniques used to solve the problem to a class of
		   single-instruction multiple-data computers known as
		   processor arrays (in our case, AMT DAP 610).
		   Simultaneously, we introduce certain hardware-oriented
		   multisection algorithms, showing their efficiency in the
		   case of small to medium size problems.},
 summary	= {The minimization of a quadratic form subject to the
		   two-norm constraint is considered. The existence of local
		   minima is investigated. The problem is approached via the
		   dual Lagrangian, and necessary and sufficient conditions
		   for the existence of all local minima are derived. The
		   suitability of the conventional numerical techniques used
		   to solve the problem on processor arrays is
		   examined. Hardware-oriented multisection algorithms are
		   considered, and their efficiency demonstrated on small
		   to medium size problems.}}

%%% M %%%

@article{Maan87,
 author		= {Z. A. Maany},
 title		= {A new algorithm for highly curved constrained optimization},
 journal	= MPS,
 volume		= 31, pages = {139--154}, year = 1987,
 abstract	= {This paper describes a new algorithm for highly curved
		   constrained optimisation. The algorithm under discussion
		   makes use of the second derivatives of both the objective
		   function and constraints. At every iteration a subproblem
		   based on the second order approximation of the objective
		   and constraints functions is solved. Three strategies to
		   solve the subproblem are used. Some computational results
		   are given. Although the performance of the subroutine is
		   very promising a number of areas are still under
		   development and further improvement is expected.},
 summary	= {An algorithm for highly curved constrained optimisation is
		   considered, which makes use of the second derivatives of
		   both the objective function and constraints. At every
		   iteration a subproblem based on the second order
		   approximation of the objective and constraints functions is
		   solved. Three strategies to solve the subproblem are used.
		   Some computational results are given.}}

@article{Mads75,
 author		= {K. Madsen},
 title		= {An algorithm for the minimax solution of overdetermined
		   systems of nonlinear equations},
 journal	= JIMA,
 volume		= 16, number = 3, pages = {321--328}, year = 1975,
 abstract       = {The problem of minimising the maximum residual of a
                   system of non-linear equations is studied in the
                   case where the number of equations is larger than
                   the number of unknowns. It is supposed that the
                   functions defining the problem have continuous first
                   derivatives and the algorithm is based on successive
                   linear approximations to these functions. The
                   resulting linear systems are solved in the minimax
                   sense, subject to bounds on the solutions, the
                   bounds being adjusted automatically, depending on
                   the goodness of the linear approximations.  It is
                   proved that the method always has sure convergence
                   properties. Some numerical examples are given.},
 summary        = {A method for nonlinear minimax in which linear models
	           are considered subject to an $\ell_{\infty}$ trust
		   region.}}
 
@article{MadyAazh94,
 author         = {R. K. Madyastha and B. Aazhang},
 title          = {An algorithm for training multilayer perceptrons for 
                   data classification and function interpolation},
 journal        = {IEEE Transactions on Circuits and Systems I: 
                   Fundamental Theory and Applications},
 volume         = 41, number = 12, pages = {866--875}, year = 1994,
 abstract       = {This paper addresses the issue of employing a
                   parametric class of nonlinear models to describe
                   nonlinear systems. This model class consists of a
                   subclass of artificial neural networks, multilayer
                   perceptrons. Specifically, we discuss the application
                   of a "globally" convergent optimization scheme to the
                   training of the multilayer perceptron. The algorithm
                   discussed is termed the conjugate gradients-trust
                   regions algorithm (CGTR) and combines the merits of
                   two well known "global" algorithms-the conjugate
                   gradients and the trust region algorithms. In this
                   paper we investigate the potential of the multilayer
                   perceptron, trained using the CGTR algorithm, towards
                   function approximation in two diverse scenarios: i)
                   signal classification in a multiuser communication
                   system, and ii) approximating the inverse kinematics
                   of a robotic manipulator. Until recently, the most
                   widely used training algorithm has been the
                   backpropagation algorithm, which is based on the
                   linearly convergent steepest descent algorithm. It is
                   seen that the multilayer perceptron trained with the
                   CGTR algorithm is able to approximate the desired
                   functions to a greater accuracy than when trained
                   using backpropagation. Specifically, in the case of
                   the multiuser communication problem, we obtain lower
                   probabilities of error in demodulating a given user's
                   signal and in the robotics problem, we observe lower
                   root mean square errors in approximating the inverse
                   kinematics function.},
 summary        = {The application of a globally convergent optimization
		   scheme to the training of the multilayer perceptron is
		   discussed. The algorithm combines the conjugate-gradients
		   and the trust-region algorithms. The potential of the
		   multilayer perceptron, trained using the algorithm, is
		   considered in signal classification in a multiuser
		   communication system, and in approximating the inverse
		   kinematics of a robotic manipulator. It is
                   seen that the multilayer perceptron trained with the
                   trust-region algorithm is able to approximate the desired
                   functions to a greater accuracy than when trained
                   using backpropagation. Specifically, in the case of
                   the multiuser communication problem, lower
                   probabilities of error in demodulating a given user's
                   signal, and, in the robotics problem, lower
                   root mean square errors in approximating the inverse
                   kinematics function, are obtained.}}


@inproceedings{Mall97,
 author		= {M. K. Mallick},
 title		= {Applications of Nonlinear Orthogonal Distance Regression in
		   3D Motion Estimation},
 crossref	= {VanH97}, pages = {273--282}}

@book{Mang69,
 author		= {O. L. Mangasarian},
 title		= {Nonlinear Programming},
 publisher	= MACGH, address = MACGH-ADDRESS,
 year		= 1969,
 note           = {Reprinted as \emph{Classics in Applied Mathematics 10}, SIAM,
		   Philadelphia, USA, 1994}}

@article{Mang80,
 author 	= {O. L. Mangasarian},
 title  	= {Locally unique solutions of quadratic programs, linear and
          	   non-linear complementarity problems},
 journal 	= MP,
 volume 	= 19, number = 2, pages = {200--212}, year = 1980}


@article{MangFrom67,
 author		= {O. L. Mangasarian and S. Fromovitz},
 title		= {The {F}ritz {J}ohn necessary optimality conditions in the
		   presence of equality and inequality constraints},
 journal	= {Journal of Mathematical Analysis and Applications},
 volume		= 17, pages = {37--47}, year = 1967}

@article{MangSolo93,
 author		= {O. L. Mangasarian and M. V. Solodov},
 title		= {Nonlinear complementarity as unconstrained and constrained
		   minimization},
 journal	= MPB,
 volume		= 62, number = 2, pages = {277--297}, year = 1993}

@phdthesis{Mara78,
 author		= {N. Maratos},
 title		= {Exact penalty function algorithms for finite-dimensional
		   and control optimization problems},
 school		= {University of London}, address = {London, England},
 year		= 1978}

@article{Marq63,
 author		= {D. Marquardt},
 title		= {An Algorithm For Least-Squares Estimation Of Nonlinear
		   Parameters},
 journal	= {SIAM Journal on Applied Mathematics},
 volume		= 11, pages = {431--441}, year = 1963,
 summary	= {Taylor-series and steepest-descent methods are sometimes
		   ineffective as algorithms for the least-squares estimation
		   of nonlinear parameters. A maximum neighbourhood method is
		   developed which, in effect, performs an optimum
		   interpolation between Taylor-series and steepest-descent
		   methods. The interpolation is based upon the maximum
		   neighbourhood in which the truncated Taylor series gives an
		   adequate representation of the nonlinear model.}}

@article{Mart70,
 author		= {B. Martinet},
 title		= {R\'{e}gularisation d'in\'{e}quations variationnelles par
		   approximations successives},
 journal	= {Revue Fran\c{c}aise d'Informatique et de Recherche
		   Op\'{e}rationnelle},
 volume		= 4, pages = {154--159}, year = 1970}

@article{Mart87,
 author		= {J. M. Mart\'{\i}nez},
 title		= {An algorithm for solving sparse nonlinear least squares
		   problems},
 journal	= {Computing},
 volume		= 39, number = 4, pages = {307--325}, year = 1997,
 abstract	= {We introduce a new method for solving Nonlinear Least
		   Squares problems when the Jacobian matrix of the system is
		   large and sparse. The main features of the new method are
		   the following: 1) the Gauss-Newton equation is
		   ``partially'' solved at each iteration using a
		   preconditioned Conjugate Gradient algorithm, 2) the new
		   point is obtained using a two-dimensional trust region
		   scheme, similar to the one introduced by
		   \citebb{BultVial87}. We prove global convergence results
		   and we present some numerical results.},
 summary	= {A method is given for solving nonlinear least-squares
		   problems, when the Jacobian matrix of the system is large
		   and sparse. The main features of the method are that
		   the Gauss-Newton equation is ``partially'' solved at each
		   iteration using a preconditioned conjugate-gradient
		   algorithm, and that the new point is obtained using a
		   two-dimensional trust region scheme, similar to the one
		   introduced by \citebb{BultVial87}. Global convergence
		   results and numerical results are presented.}}

@article{Mart94,
 author		= {J. M. Mart\'{\i}nez},
 title		= {Local minimizers of quadratic functions on {E}uclidean
		   balls and spheres},
 journal	= SIOPT,
 volume		= 4, number = 1, pages = {159--176}, year = 1994,
 abstract	= {In this paper a characterization of the local-nonglobal
		   minimizer of a quadratic function defined on a Euclidean
		   ball or sphere is given. It is proven that there exists at
		   most one local-nonglobal minimizer and that the Lagrange
		   multiplier that corresponds to this minimizer is the
		   largest solution of a nonlinear scalar equation. An
		   algorithm is proposed for computing the local-nonglobal
		   minimizer.},
 summary	= {A characterization of the local-non-global minimizers of a
		   quadratic function defined on a Euclidean ball or sphere is
		   given. It is proven that there exists at most one
		   local-non-global minimizer and that the Lagrange multiplier
		   that corresponds to this minimizer is the largest solution
		   of a nonlinear scalar equation. An algorithm is proposed
		   for computing the local-non-global minimizer.}}

@article{Mart95,
 author		= {J. M. Mart\'{\i}nez},
 title		= {Discrimination by Means of a Trust Region Method},
 journal	= {International Journal of Computer Mathematics},
 volume		= 55, number = {1--2}, pages = {91--103}, year = 1995,
 abstract	= {Suppose that the individuals of a population are divided
		   into two groups according to some unknown merit criterion.
		   It is required to determine weights for a set of variables
		   which should be positively correlated with merit, in such a
		   way that scores of the individuals in the superior group
		   are above some level, and vice-versa. This may be modelled
		   as an easily-solvable convex optimization problem. Examples
		   are given.},
 summary	= {The individuals of a population are divided in two groups
		   according to some unknown merit criterion and the problem
		   is considered to determine weights for a set of variables
		   which should be positively correlated with merit, in such a
		   way that scores of the individuals in the superior group
		   are above some level, and vice-versa. This situation is
		   modeled as an easy convex optimization problem.}}

@article{MartSant97,
 author		= {J. M. Mart\'{\i}nez and S. A. Santos},
 title		= {New convergence results on an algorithm for norm
		   constrained regularization and related problems},
 journal	= RAIRO-OR,
 volume		= 31, number = 3, pages = {269--294}, year = 1997,
 abstract	= {The constrained least-squares regularization of nonlinear
		   ill-posed problems is a nonlinear programming problem for
		   which trust-region methods have been developed. In this
		   paper we complement the convergence theory of one of those
		   methods showing that, under suitable hypotheses, local
		   (superlinear or quadratic) convergence holds and every
		   accumulation point is second-order stationary.},
 summary	= {The constrained least-squares regularization of nonlinear
		   ill-posed problems is a nonlinear programming problem for
		   which trust-region methods have been developed. It is shown
		   that for one such method, under suitable hypotheses, local
		   (superlinear or quadratic) convergence occurs and every
		   accumulation point is second-order stationary.}}

@article{MartMore97,
 author		= {J. M. Mart\'{\i}nez and A. C. Moretti},
 title		= {A trust region method for minimization of nonsmooth
		   functions with linear constraints},
 journal	= MP,
 volume		= 76, number = 3, pages = {431--449}, year = 1997,
 abstract	= {We introduce a trust region algorithm for minimization of
		   nonsmooth functions with linear constraints. At each
		   iteration, the objective function is approximated by a
		   model function that satisfies a set of assumptions stated
		   recently by \citebb{QiSun94} in the context of
		   unconstrained nonsmooth optimization. The trust region
		   iteration begins with the resolution of an ``easy
		   problem'', as in the recent works of \citebb{MartSant95}
		   and \citebb{FrieMartSant94}, for smooth constrained
		   optimization. In practical implementations we use the
		   infinity norm for defining the trust-region, which fits
		   well with the domain of the problem. We prove global
		   convergence and report numerical experiments related to the
		   parameter estimation problem.},
 summary	= {A trust-region algorithm for minimization of non-smooth
		   functions with linear constraints is introduced. At each
		   iteration, the objective function is approximated by a
		   model that satisfies assumptions stated by \citebb{QiSun94}
		   for unconstrained non-smooth optimization. The trust-region
		   iteration begins with the solution of an ``easy problem'',
		   as in \citebb{MartSant95} and \citebb{FrieMartSant94}. In
		   practical implementations, the infinity norm is used to
		   define the trust region. Global convergence is established,
		   and numerical experiments for the parameter estimation
		   problem reported.}}

@article{MartSant95,
 author		= {J. M. Mart\'{\i}nez and S. A. Santos},
 title		= {A trust-region strategy for minimization on arbitrary
		   domains},
 journal	= MP,
 volume		= 68, number = 3, pages = {267--301}, year = 1995,
 abstract	= {We present a trust-region method for minimizing a general
		   differentiable function restricted to an arbitrary closed
		   set. We prove a global convergence theorem. The
		   trust-region method defines difficult subproblems that are
		   solvable in some particular cases. We analyze in detail the
		   case where the domain is a Euclidean ball. For this case we
		   present numerical experiments where we consider different
		   Hessian approximations.},
 summary	= {A trust-region method for minimizing a general
		   differentiable function restricted to an arbitrary closed
		   set is presented, and global convergence is proved. The
		   case where the domain is a Euclidean ball is analysed in
		   detail. For this case, numerical experiments which consider
		   a variety of Hessian approximations are presented.}}
 
@article{MaurZowe79,
 author		= {H. Maurer and J. Zowe},
 title		= {First and second-order necessary and sufficient optimality
		   conditions for infinite-dimensional programming problems},
 journal	= MP,
 volume		= 16, pages = {98--110}, year = 1979}

@article{MaurMacu97,
 author		= {D. Mauricio and N. Maculan},
 title		= {A trust region method for zero-one nonlinear programming},
 journal	= RAIRO-OR,
 volume		= 31, number = 4, pages = {331--341}, year = 1997,
 abstract	= {An $O(n \log n)$ trust region approximation method to solve
		   $0-1$ non-linear programming is presented. Optimality
		   conditions and numerical results are reported.},
 summary	= {An $O(n \log n)$ trust region approximation method to solve
		   $0-1$ nonlinear programming is presented. Optimality
		   conditions and numerical results are reported.}}

@article{MaynMara79,
 author		= {D. Q. Mayne and N. Maratos},
 title		= {A first-order, exact penalty function algorithm for
		   equality constrained optimization problems},
 journal	= MP,
 volume		= 16, number = 3, pages = {303--324}, year = 1979}

@article{MaynPola82,
 author		= {D. Q. Mayne and E. Polak},
 title		= {A superlinearly convergent algorithm for constrained
		   optimization problems},
 journal	= MPS,
 volume		= 16, pages = {45--61}, year = 1982}

@article{McAfGayHozaLaudSchwSund86,
 author         = {K. B. McAfee and D. M. Gay and R. S. Hozack and 
                   R. A. Laudise and G. Schwartz and W. A. Sunder},
 title          = {Thermodynamic considerations in the synthesis and crystal 
                   growth of GaSb},
 journal        = {Journal of Crystal Growth},
 volume         = 76, number = 2, pages = {263--271}, year = 1986,
 abstract       = {A newly developed optimization algorithm, the 'sticky
                   trust region technique', for Gibbs energy
                   minimization is used to determine the gaseous species
                   and liquid and solid phases present during the
                   synthesis and crystal growth of GaSb. The growth
                   system involves almost thirty species comprising a
                   gaseous phase and nine condensed species. The system
                   is modelled as a function of temperature, oxygen and
                   hydrogen pressure in the presence of an SiO/sub 2/
                   crucible. Ga/sub 2/O/sub 3/ is identified as the most
                   stable contaminant compound and is seen as a phase
                   that floats on the liquid melt during growth. This
                   oxide often prevents the growth of high quality
                   crystals.},
 summary        = {The ``sticky trust region technique'' for Gibbs energy
                   minimization is used to determine the gaseous species
                   and liquid and solid phases present during the
                   synthesis and crystal growth of GaSb. The growth
                   system involves almost thirty species comprising a
                   gaseous phase and nine condensed species. }}


@article{McAfGayHozaLaudSund88,
 author         = {K. B. McAfee and D. M. Gay and R. S. Hozack and 
                   R. A. Laudise and W. A. Sunder},
 title          = {Thermodynamic stability and reactivity of {A}l{S}b and their 
                   relationship to crystal growth},
 journal        = {Journal of Crystal Growth},
 volume         = 88, number = 4, pages = {488--498}, year = 1988,
 abstract       = {The vapor pressure, species concentration and
                   reactivity of AlSb is modeled thermodynamically using
                   the newly-described sticky trust region technique,
                   STRT, for free energy minimization. The conditions
                   chosen include oxygen and hydrogen concentrations
                   appropriate to Czochralski crystal growth in SiO/sub
                   2/, C, BN, Al/sub 2/O/sub 3/ and BeO crucibles and
                   growth in the absence of a crucible. Results are
                   compared with crystal growth experiments where
                   appropriate. At the melting point the principal vapor
                   species is Sb/sub 2/ with a total vapor pressure of
                   approximately 10/sup -3/ atm, which is about 10/sup
                   2/ larger than for GaSb.},
 summary        = {The vapor pressure, species concentration and
                   reactivity of AlSb is modeled thermodynamically using
                   the newly-described sticky trust-region technique,
                   STRT, for free energy minimization. The conditions
                   chosen include oxygen and hydrogen concentrations
                   appropriate to Czochralski crystal growth.}}

@article{McCa98,
 author		= {McCartin, B. J.},
 title		= {A model-trust region algorithm utilizing a quadratic
		   interpolant},
 journal	= JCAM,
 volume		= 91, number = 2, pages = {249--259}, year = 1998,
 abstract	= {A new model-trust region algorithm for problems in
		   unconstrained optimization and nonlinear equations
		   utilizing a quadratic interpolant for step selection is
		   presented and analyzed. This is offered as an alternative
		   to the piecewise-linear interpolant employed in the widely
		   used ''double dogleg'' step selection strategy. After the
		   new step selection algorithm has been presented, we offer a
		   summary, with proofs, of its desirable mathematical
		   properties. Numerical results illustrating the efficacy of
		   this new approach are presented.},
 summary	= {A model-trust region algorithm for problems in
		   unconstrained optimization and nonlinear equations
		   utilizing a quadratic interpolant is presented and
		   analyzed. This is offered as an alternative to the
		   piecewise-linear interpolant employed in the double dogleg
		   strategy. A step selection algorithm is presented, along
		   with a summary, with proofs, of its desirable mathematical
		   properties. Numerical results are presented.}}

@article{McCo69,
 author		= {G. P. McCormick},
 title		= {Anti-zig-zagging by bending},
 journal	= {Management Science},
 volume		= 15, pages = {315--319}, year = 1969}

@techreport{McCo91,
 author		= {G. P. McCormick},
 title		= {The superlinear convergence of a nonlinear primal-dual
		   algorithm},
 institution	= {Department of Operations Research, George Washington
		   University, Washington},
 type		= {Technical Report}, number = {OR T-550/91}, year = 1991}

@article{McKeMesiZeni95,
 author		= {M. P. McKenna and J. P. Mesirov and S. A. Zenios},
 title		= {Data Parallel Quadratic Programming on Box-Constrained
		   Problems},
 journal	= SIOPT,
 volume		= 5, number = 3, pages = {570--589}, year = 1995}

@article{MehrSun91,
 author 	= {S. Mehrotra and J. Sun},
 title  	= {A method of analytic centers for quadratically constrained 
       		   convex quadratic programs},
 journal 	= SINUM,
 volume 	= 28, number = {}, pages = {529--544}, year = 1991}

@article{MentAnde91,
 author		= {J. Mentel and H. Anderson},
 title		= {A new Kind of Parameter-Estimation of Reactions Under
		   Dynamic Temperature Program},
 journal	= {Thermochimica Acta},
 volume		= 187, number = {SEP}, pages = {121--132}, year = 1991,
 abstract	= {For kinetic evaluation of TG, DTA and DSC of simple and
		   complex reactions we tried to apply a parameter adjustment
		   by means of non- linear optimization (trust-region method
		   with Marquardt-routine). Including all experimental data
		   and using the differential equation systems, we found many
		   advantages over the usual linearizing methods. The problems
		   of consecutive and competing reactions as well as those
		   with steady states (enzyme kinetics) were solved
		   satisfactorily if two or more data sets with different
		   heating rates are known. Supplementary use of other
		   analytical methods are recommendable.},
 summary	= {A trust-region method is applied a parameter estimation
		   related to kinetic evaluation of TG, DTA and DSC of simple
		   and complex reactions. When all experimental data is
		   included and the differential equation systems used, this
		   proves advantageous compared to usual linearizing methods.
		   The problems of consecutive and competing reactions as well
		   as those with steady states (enzyme kinetics) are solved
		   satisfactorily if two or more data sets with different
		   heating rates are known. Supplementary use of other
		   analytical methods are recommended.}}

@article{MentTillMollHabe92,
 author		= {J. Mentel and V. Tiller and E. Moller and D. Haberland},
 title		= {Estimation of Parameters in Systems of Ordinary
		   Differential-Equations to the Determination of
		   Kinetic-Parameters},
 journal	= {Chemische Technik},
 volume		= 44, number = 9, pages = {300--303}, year = 1992,
 abstract	= {The integral determination of kinetic constants in complex
		   systems was handled as a special case of parameter
		   estimation in systems of differential equations. The
		   program for parameter estimation is written in Turbo-Pasca.
		   A Trust-Region method with Levenberg- Marquardt routine was
		   used. Especially with the use of the stable BDF-integration
		   routine it is possible that the start values differ some
		   magnitudes from the solution. Simulations of different
		   models Prove the efficiency of the evaluation also with
		   non-smooth data. In these cases it is not allowed to
		   calculate concentrations needed for the evaluation with the
		   help of stoichiometric relations.},
 summary	= {The integral determination of kinetic constants in complex
		   systems is handled as a special case of parameter
		   estimation in systems of differential equations. A
		   trust-region method is used. A stable
		   BDF-integration routine allows the use of bad initial
		   values. Simulations of
		   different models prove the efficiency of the method even
		   with non-smooth data. In these cases it is not possible to
		   calculate concentrations needed for the evaluation with the
		   help of stoichiometric relations.}}

@article{Miff75,
 author		= {R. Mifflin},
 title		= {A superlinearly convergent algorithm for minimization
		   without evaluating derivatives},
 journal	= MP,
 volume		= 9, number = 1, pages = {100--117}, year = 1975}

@article{Miff75b,
 author		= {R. Mifflin},
 title		= {Convergence bounds for nonlinear programming algorithms},
 journal	= MP,
 volume		= 8, number = 3, pages = {251--271}, year = 1975}

@article{MineFukuTana84,
 author         = {H. Mine and M. Fukushima and Y. Tanaka},
 title          = {On the use of epsilon -most-active constraints in an exact 
                   penalty function method for nonlinear optimization},
 journal        = {IEEE Transactions on Automatic Control},
 volume         = {AC-29}, number = 11, pages = {1040--1042}, year = {1984},
 abstract       = {An algorithm for nonlinear programming problems is
                   presented which utilizes the epsilon -most-active
                   constraint strategy in an exact penalty function
                   method with trust region. The algorithm is
                   particularly suitable for problems containing a large
                   number of constraints. The global convergence of the
                   proposed algorithm is proved. The results of limited
                   computational experiments on discretized
                   semi-infinite programming problems are reported to
                   demonstrate the effectiveness of the present
                   approach.},
 summary        = {An globally convergent algorithm for nonlinear
		   programming problems is presented which utilizes
		   the epsilon -most-active constraint strategy in an
		   exact penalty function method with trust region. The
		   algorithm is particularly suitable for problems
		   containing a large number of constraints. Some
                   computational experiments are reported.}}

@article{MongSart95,
 author		= {M. Mongeau and A. Sartenaer},
 title		= {Automatic decrease of the penalty parameter in exact
		   penalty function methods},
 journal	= {European Journal of Operational Research},
 volume		= 83, number = 3, pages = {686--699}, year = 1995}

@article{MontAdle89,
 author 	= {R. D. C. Monteiro and I. Adler},
 title  	= {Interior path following primal-dual algorithms. 2. {C}onvex
         	   quadratic programming},
 journal 	= MP,
 volume 	= 44, number = 1, pages = {43--66}, year = 1989}

@article{MontWang98,
 author		= {R. D. C. Monteiro and Y. Wang},
 title		= {Trust region affine scaling algorithms for linearly
		   constrained convex and concave programs},
 journal	= MP,
 volume		= 80, number = 3, pages = {283--310}, year = 1998,
 abstract	= {We study a trust region affine scaling algorithm for
		   solving the linearly constrained convex or concave
		   programming problem. Under primal nondegeneracy assumption,
		   we prove that every accumulation point of the sequence
		   generated by the algorithm satisfies the first order
		   necessary condition for optimality of the problem. For a
		   special class of convex or concave functions satisfying a
		   certain invariance condition on their Hessians, it is shown
		   that the sequence of iterates and objective function values
		   generated by the algorithm converge R-linearly and
		   Q-linearly, respectively. Moreover, under primal
		   nondegeneracy and for this class of objective functions, it
		   is shown that the limit point of the sequence of iterates
		   satisfies the first and second order necessary conditions
		   for optimality of the problem.},
 summary	= {A trust region affine scaling algorithm for solving the
		   linearly constrained convex or concave programming problem
		   is presented. Under primal non-degeneracy assumption, every
		   accumulation point of the sequence generated by the
		   algorithm satisfies the first order necessary condition.
		   For a special class of convex or concave
		   functions satisfying a certain invariance condition on
		   their Hessians, the sequence of iterates and objective
		   function values converge R-linearly and Q-linearly,
		   respectively. Moreover, under primal non-degeneracy and for
		   this class of objective functions, the limit point of the
		   sequence of iterates satisfies the first and second-order
		   necessary conditions.}}

@article{MontTsuc98,
 author		= {R. D. C. Monteiro and T. Tsuchiya},
 title		= {Global convergence of the affine scaling algorithm for
		   convex quadratic programming},
 journal	= SIOPT,
 volume		= 8, number = 1, pages = {26--58}, year = 1998,
 summary	= {A global convergence proof of the second-order affine
		   scaling algorithm for convex quadratic programming problems
		   is given, where the new iterate is the point that minimizes
		   the objective function over the intersection of the
		   feasible region with the ellipsoid centered at the current
		   point and whose radius is a fixed fraction $\beta \in
		   (0,1)]$ of the radius of the largest ``scaled'' ellipsoid
		   inscribed in the nonnegative orthant. The analysis is based
		   on the local Karmarkar potential function introduced by
		   Tsuchiya. For any $\beta \in (0,1)$ and without making any
		   nondegeneracy assumption on the problem, the sequences of
		   primal iterates and dual estimates converge to
		   optimal solutions of the quadratic program and its dual.}}

@inproceedings{More78,
 author		= {J. J. Mor\'{e}},
 title		= {The {L}evenberg-{M}arquardt algorithm: implementation and
		   theory},
 crossref	= {Wats78}, pages = {105--116},
 summary        = {A robust implementation of the
                   Levenberg-Morrison-Marquardt algorithm for nonlinear
                   least squares is discussed. The proposed method is shown
                   to have strong convergence properties. In addition to
                   robustness, the main features are the proper use of
                   implicitly scaled variables and the choice of the
                   Levenberg-Morrison-Marquardt parameter via a scheme due to
                   \citebb{Hebd73}. Numericial results illustrating the
                   behaviour of this implementation are presented.}}

@inproceedings{More83,
 author		= {J. J. Mor\'{e}},
 title		= {Recent developments in algorithms and software for trust
		   region methods},
 crossref	= {BachGrotKort83}, pages = {258--287},
 abstract	= {Trust region methods are an important class of iterative
		   methods for the solution of systems of nonlinear equations,
		   nonlinear estimation problems and large-scale optimization.
		   Interest in trust region methods derives, in part, from the
		   availability of strong convergence results and from the
		   development of software for these methods which is
		   reliable, efficient, and amazingly free of ad-hoc
		   decisions. In this paper we survey the theoretical and
		   practical results available for trust region methods and
		   discuss the relevance of these results to the
		   implementation of trust region methods},
 summary	= {The theoretical and practical results available for
		   trust-region methods in systems of nonlinear equations,
		   nonlinear estimation problems and large-scale optimization
		   are surveyed, and their relevance to the implementation
		   of trust-region methods discussed.}}

@inproceedings{More88,
 author		= {J. J. Mor\'{e}},
 title		= {Trust regions and projected gradients},
 booktitle	= {System Modelling and Optimization},
 editor		= {M. Iri and K. Yajima},
 publisher	= SPRINGER, address = SPRINGER-ADDRESS,
 volume		= 113, pages = {1--13}, year = 1988,
 note		= {Lecture Notes in Control and Information Sciences},
 abstract	= {The numerical solution of large scale linearly constrained
		   problems by algorithms which use the gradient projection
		   method is a promising research area. Algorithms based on
		   the gradient projection method are able to drop and add
		   many constraints at each iteration, and this ability gives
		   them an important advantage in large scale problems. In
		   this paper we show how the ideas from the gradient
		   projection method combine with trust region methods, and we
		   give an indication of the powerful convergence results that
		   are available for algorithms of this type.},
 summary	= {It is shown how the ideas from the gradient projection
		   method combine with trust-region methods, and an indication
		   of the powerful convergence results that are available for
		   gradient-projection algorithms is given.}}

@article{More93,
 author		= {J. J. Mor\'{e}},
 title		= {Generalizations of the trust region problem},
 journal	= OMS,
 volume		= 2, number = 3, pages = {189--209}, year = 1993,
 abstract	= {The trust region problem requires the global minimum of a
		   general quadratic function subject to an ellipsoidal
		   constraint. The development of algorithms for the solution
		   of this problem has found applications in nonlinear and
		   combinatorial optimization. In this paper we generalize the
		   trust region problem by allowing a general quadratic
		   constraint. The main results are a characterization of the
		   global minimizer of the generalized trust region problem,
		   and the development of an algorithm that finds an
		   approximate global minimizer in a finite number of
		   iterations.},
 summary	= {The trust region subproblem is generalized by allowing a
		   general quadratic constraint. The main results are a
		   characterization of the global minimizer of the generalized
		   trust-region problem, and the development of an algorithm
		   that finds an approximate global minimizer in a finite
		   number of iterations.}}

@techreport{MoreGarbHill80,
 author		= {J. J. Mor\'{e} and B. S. Garbow and K. E. Hillstrom},
 title		= {User guide for {MINPACK-1}},
 institution	= ANL, address = ANL-ADDRESS,
 number		= {80--74}, year = 1980}

@article{MoreGarbHill81,
 author		= {J. J. Mor\'{e} and B. S. Garbow and K. E. Hillstrom},
 title		= {Testing Unconstrained Optimization Software},
 journal	= TOMS,
 volume		= 7, number = 1, pages = {17--41}, year = 1981}

@article{MoreSore83,
 author		= {J. J. Mor\'{e} and D. C. Sorensen},
 title		= {Computing A Trust Region Step},
 journal	= SISSC,
 volume		= 4, number = 3, pages = {553--572}, year = 1983,
 abstract	= {We propose an algorithm for the problem of minimizing a
		   quadratic function subject to an ellipsoidal constraint and
		   show that this algorithm is guaranteed to produce a nearly
		   optimal solution in a finite number of iterations. We also
		   consider the use of this algorithm in a trust region
		   Newton's method. In particular, we prove that under
		   reasonable assumptions the sequence generated by Newton's
		   method has a limit point which satisfies the first and
		   second order necessary conditions for a minimizer of the
		   objective function. Numerical results for GQTPAR, which is
		   a Fortran implementation of our algorithm, show that GQTPAR
		   is quite successful in a trust region method. In our tests
		   a call to GQTPAR only required $1.6$ iterations on the
		   average.},
 summary	= {An algorithm for minimizing a quadratic function subject to
		   an ellipsoidal constraint is proposed. This algorithm is
		   guaranteed to produce a nearly optimal solution in a finite
		   number of iterations. The use of this algorithm in a
		   trust-region Newton's method is also considered. In
		   particular, it is shown that, under reasonable assumptions
		   the sequence generated by Newton's method has a limit point
		   which satisfies first and second order necessary conditions
		   for a minimizer. Numerical results for GQTPAR, a Fortran
		   implementation of the algorithm, show that it is quite
		   successful in a trust-region method. In these tests, a call
		   to GQTPAR only required $1.6$ iterations on the average.}}

@inproceedings{MoreSore84,
 author		= {J. J. Mor\'{e} and D. C. Sorensen},
 title		= {{N}ewton's method},
 booktitle	= {Studies in Numerical Analysis},
 editor		= {G. H. Golub},
 publisher	= AMS, address = AMS-ADDRESS,
 series		= {MAA Studies in Mathematics}, number = 24, pages = {29--82},
 year		= 1984,
 abstract	= {Newton's method plays a central role in the development of
		   numerical techniques for optimization. In fact, most of the
		   current practical methods for optimization can be viewed as
		   variations on {N}ewton's method. It is therefore important
		   to understand {N}ewton's method as an algorithm in its own
		   right and as a key introduction to the mot recent ideas in
		   this area. One of the aims of this expository paper is to
		   present and analyze two main approaches to {N}ewton's
		   method for unconstrained optimization: the line search
		   approach and the trust region approach. The other aim is to
		   present some of the recent developments in the optimization
		   field which are related to {N}ewton's method. In
		   particular, we explore several variations on {N}ewton's
		   method which are appropriate for large scale problems, and
		   we also show how quasi-{N}ewton methods can be derived
		   quite naturally from {N}ewton's method.},
 summary	= {The linesearch and trust region approaches for unconstrained
		   optimization are discussed, and some of the recent 
		   developments related to Newton's method are presented.
		   In particular, several variations on {N}ewton's method
		   which are appropriate for large-scale problems are explored,
		   and it is shown how quasi-Newton methods can be derived
		   quite naturally from Newton's method.}}

@article{MoreTora91,
 author		= {J. J. Mor\'{e} and G. Toraldo},
 title		= {On the Solution of Large Quadratic Programming Problems
		   with Bound Constraints},
 journal	= SIOPT,
 volume		= 1, number = 1, pages = {93--113}, year = 1991}

@book{MoreWrig93,
 author		= {J. J. Mor\'{e} and S. J. Wright},
 title		= {Optimization Software Guide},
 publisher	= SIAM, address = SIAM-ADDRESS,
 number		= 14, series = {Frontiers in Applied Mathematics},
 year		= 1993}

@article{More62,
 author		= {J. J. Moreau},
 title		= {D\'{e}composition orthogonale d'un espace {H}ilbertien
		   selon deux c\^{o}nes mutuellement polaires},
 journal	= {Comptes-Rendus de l'Acad\'{e}mie des Sciences (Paris)},
 volume		= 255, pages = {238--240}, year = 1962}

@inproceedings{Morr60,
 author		= {D. D. Morrison},
 title		= {Methods for nonlinear least squares problems and
		   convergence proofs},
 booktitle	= {Proceedings of the Seminar on Tracking Programs and Orbit
		   Determination},
 editor		= {J. Lorell and F. Yagi},
 publisher	= {Jet Propulsion Laboratory}, address = {Pasadena, USA},
 pages		= {1--9}, year = 1960,
 abstract	= {The STL tracking programs are designed o compute by least
		   squares the most probable trajectory of a missile, fom
		   observed radar or optical data. These data can be any
		   combination of range, azimuth, elevation, range rate, hour
		   angle and declination, or direction cosines, with respect
		   to a given location. A differential correction method is
		   used, starting from an initial estimate, and the iteration
		   continues until the residuals (observed minus computed
		   values) are either all within specified limits, or until
		   there is no further improvement. Errors above a certain
		   absolute value are automatically eliminated. One program
		   has been prepared primarily for lunar and interplanetary
		   flights. In this, Cowell's method of trajectory computation
		   is used. The partial derivatives used in the least squares
		   solution are found by solving the related variational
		   equations. Here, the trajectory elements, to which the
		   corrections are applied, are the componenets of position
		   and velocity of the missile at a particular point in the
		   trajectory (expressed in speherical coordinates). For
		   earth-satellite tracking, the elliptic elements of the
		   osculating ellipse are used to specify the trajectory.
		   Herricks' variation of elements method is used to compute
		   the trajectory, and the partial derivatives are computed
		   analytically. For these two programs a special least square
		   subroutine has been prepared in which convergence can be
		   assumed by limiting the amount any variable can change in
		   one iteration. The standard deviation of each variable is
		   printed out. After a trajectory has been fitted to a
		   ceratin set of data, additional data can be added without
		   the necessity of reprocessing the original set, a feature
		   which is especially valuable in regard to computing time.},
 summary	= {Least-squares estimation of missile trajectory is
		   considered in the context of lunar and interplanetary
		   flights as well as earthbound satellite tracking. A
		   least-square subroutine is described in which convergence
		   can be assumed by limiting the amount any variable can
		   change in one iteration. A method is given that allows the
		   computation of a quadratic model of the objective function
		   within a sphere using a single linear system depending on a
		   parameter. Monotonicity of the optimal model value as a
		   function of this parameter is proved.}}

@article{MukaPola75,
 author		= {H. Mukai and E. Polak},
 title		= {A quadratically convergent primal-dual algorithm with
		   global convergence properties for solving optimization
		   problems with inequality constraints},
 journal	= MP,
 volume		= 9, number = 3, pages = {336--349}, year = 1975}

@article{MukaTatsFuku98,
 author         = {K. Mukai and K. Tatsumi and M. Fukushima},
 title          = {An approximation algorithm for quadratic cost 0-1 mixed 
                   integer programming problems},
 journal        = {Transactions of the Institute of Electronics, Information 
                   and Communication Engineers A},
 volume         = {J81-A}, number = 4, pages = {649--657}, year = 1998,
 abstract       = {In this paper, we focus on the quadratic cost 0-1
                   mixed integer programming problem. First, we
                   formulate the problem as a two-level programming
                   problem that consists of the lower level continuous
                   quadratic programming problem with 0-1 variables
                   being fixed and the upper level nonlinear 0-1
                   programming problem. We propose an approximation
                   algorithm for solving the upper level 0-1 programming
                   problem. This algorithm approximately solves a
                   subproblem obtained by linearizing the objective
                   function at a current point. To guarantee the descent
                   property of the generated sequence, we use a trust
                   region technique that adaptively controls a penalty
                   constant in the objective function of the
                   subproblem. To solve subproblems, we apply a Hopfield
                   network with a new transition rule that allows a
                   temporary state transition based on the variable
                   depth method. Some numerical experiments for a
                   location-transportation problem with quadratic costs
                   indicate that the proposed algorithm is practically
                   effective.},
 summary        = {The quadratic cost 0-1 mixed integer programming problem 
		   is formulated as a two-level programming
                   problem that consists of the lower level continuous
                   quadratic programming problem with 0-1 variables
                   being fixed and the upper level nonlinear 0-1
                   programming problem. An approximation
                   algorithm for solving the upper level 0-1 programming
                   problem is proposed that approximately solves a
                   subproblem obtained by linearizing the objective
                   function at a current point. To guarantee the descent
                   property of the generated sequence, a trust-region
		   technique adaptively controls a penalty 
                   constant in the objective function of the
                   subproblem. To solve subproblems, a Hopfield
                   network is applied with a new transition rule that allows a
                   temporary state transition based on the variable
                   depth method. Some numerical experiments for a
                   location-transportation problem with quadratic costs
                   indicate that the proposed algorithm is practically
                   effective.}}


@inproceedings{Murr69,
 author		= {W. Murray},
 title		= {An algorithm for constrained minimization},
 crossref	= {Flet69}, pages = {189--196}}

@article{Murr71,
 author		= {W. Murray},
 title		= {Analytical expressions for eigenvalues and eigenvectors of
		   the {H}essian matrices of barrier and penalty functions},
 journal	= JOTA,
 volume		= 7, pages = {189--196}, year = 1971}

@techreport{Murr71b,
 author  	= {W. Murray},
 title   	= {An algorithm for finding a local minimum of an indefinite
            	   quadratic program},
 institution 	= NPL, address = NPL-ADDRESS,
 number 	= {NAC 1}, year = 1971}

@inproceedings{Murr92,
 author		= {W. Murray},
 title		= {Ill-conditioning in Barrier Methods},
 booktitle	= {Advances in numerical partial differential equations and
		   optimization, Proceedings of the Sixth Mexico-United States
		   Workshop},
 publisher	= SIAM, address = SIAM-ADDRESS,
 year		= 1992}

@techreport{MurrWrig78,
 author		= {W. Murray and M. H. Wright},
 title		= {Project {L}agrangian methods based on the trajectories of
		   penalty and barrier functions},
 institution	= STANFORD, address = STANFORD-ADDRESS,
 type		= {Technical Report}, number = {SOL78-23}, year = 1978}

@article{MurrPrie95,
 author		= {W. Murray and F. J. Prieto},
 title		= {A Sequential Quadratic Programming Algorithm Using an
		   Incomplete Solution of the Subproblem},
 journal	= SIOPT,
 volume		= 5, number = 3, pages = {590--640}, year = 1995}

@article{MurrWrig82,
 author		= {W. Murray and M. H. Wright},
 title		= {Computation of the search direction in constrained
		   optimization algorithms},
 journal	= MPS,
 volume		= 16, number = {MAR}, pages = {62--83}, year = 1982}
 
@book{Murt81,
 author  	= {B. A. Murtagh},
 title   	= {Advanced Linear Programming},
 publisher 	= MACGH, address = MACGH-ADDRESS,
 year    	= 1981}

@article{MurtKaba87,
 author		= {K. G. Murty and S. N. Kabadi},
 title		= {Some {NP}-complete problems in quadratic and nonlinear
		   programming},
 journal	= MP,
 volume		= 39, number = 2, pages = {117--129}, year = 1987}
 
%%% N %%%

@inproceedings{Nabo87,
 author		= {N. Nabona},
 title		= {Computational results of {N}ewton's method with search along
		   an approximate hook step curve for unconstrained
		   minimization},
 booktitle	= {Actas I Seminario Internacional de Investigacion Operativa
		   del Pais Vasco},
 editor		= {J. P. Vilaplana and L. F. Escudero},
 publisher	= {Argitaparen Zerbitzua Euskal Herriko Unibersitatea},
 address	= {Bilbao, Spain},
 pages		= {21--54}, year = 1987,
 summary	= {Numerical experience is presented for an unconstrained
		   optimization method in which a trust-region step is
		   computed by minimizing the model along a Bezier curve that
		   approximates the trajectory of exact minimizers as a
		   function of the trust-region radius.}}

@manual{NAG98,
 author      	= {{NAG}},
 title       	= {Fortran Library Mark 18},
 organization	= {NAG Ltd.}, address = {Oxford, England},
 year        	= 1998}

@book{Nagu93,
 author		= {A. Nagurney},
 title		= {Network Economics: a Variational Inequality Approach},
 publisher	= KLUWER, address = KLUWER-ADDRESS,
 series		= {Advances in Computational Economics}, year = 1993}

@article{Nash84,
 author		= {S. G. Nash},
 title		= {{N}ewton-type Minimization via the {L}anczos Method},
 journal	= SINUM,
 volume		= 21, number = 4, year = 1984}

@article{Nash85a,
 author		= {S. G. Nash},
 title		= {Preconditioning of truncated {N}ewton methods},
 journal	= SISSC,
 volume		= 6, number = 3, pages = {599--618}, year = 1985}

@article{NashNoce91,
 author		= {S. G. Nash and J. Nocedal},
 title		= {A Numerical Study of the Limited Memory {BFGS} Method and
		   the Truncated-{N}ewton Method for Large-Scale Optimization},
 journal	= SIOPT,
 volume		= 1, number = 3, pages = {358--372}, year = 1991}

@article{NashSofe90,
 author		= {S. G. Nash and A. Sofer},
 title		= {Assessing a search direction within a truncated-{N}ewton
		   method},
 journal	= {Operations Research Letters},
 volume		= 9, number = 4, pages = {219--221}, year = 1990}

@article{NashSofe93,
 author		= {S. G. Nash and A. Sofer},
 title		= {A barrier method for large-scale constrained optimization},
 journal	= ORSAC,
 volume		= 5, number = 1, pages = {40--53}, year = 1993}

@techreport{NashSofe98,
 author		= {S. G. Nash and A. Sofer},
 title		= {Why Extrapolation Helps in Barrier Methods},
 institution	= {Operations Research and Engineering Department, George
		   Mason University},
 address	= {Fairfax, USA},
 month		= {September}, year = 1998}

@article{NeldMead65,
 author		= {J. A. Nelder and R. Mead},
 title		= {A simplex method for function minimization},
 journal	= COMPJ,
 volume		= 7, pages = {308--313}, year = 1965}

@article{NelsPapa98,
 author		= {S. A. Nelson and P. Y. Papalambros},
 title		= {A modified trust region algorithm for hierarchical NLP},
 journal	= {Structural Optimization},
 volume		= 16, number = 1, pages = {19--28}, year = 1998,
 abstract	= {Large-scale optimization problems frequently require the
		   exploitation of structure in order to obtain efficient and
		   reliable solutions. Successful algorithms for general
		   nonlinear programming problems with theoretical
		   underpinnings do not usually accommodate any additional
		   properties of the original algorithm.},
 summary	= {Modifications are made to a trust-region algorithm to take
		   advantage of the hierarchical structure in large-scale
		   optimization problems without compromising the theoretical
		   properties of the original algorithm.}}

@article{NemiSche96,
 author 	= {A. Nemirovskii and K. Scheinberg},
 title  	= {Extension of {K}armarkar's algorithm onto convex 
        	   quadratically constrained quadratic problems},
 journal 	= MPA,
 volume 	= 72, number = 3, pages = {273--289}, year = 1996}
		
@book{NestNemi94,
 author		= {Y. Nesterov and A. Nemirovskii},
 title		= {Interior-Point Polynomial Algorithms in Convex Programming},
 publisher	= SIAM, address = SIAM-ADDRESS,
 year		= 1994}

@book{NobeDani77, 
 author  	= {B. Noble and J. W. Daniel},
 title   	= {Applied Linear Algebra},
 publisher 	= PH, address = PH-ADDRESS,
 edition 	= {second}, year = 1977}

@article{NestTodd98,
 author		= {Y. Nesterov and M. J. Todd},
 title		= {Primal-Dual Interior-Point Methods for Self-Scaled Cones},
 journal	= SIOPT,
 volume		= 8, number = 2, year = 1998}

@article{Noce80,
 author		= {J. Nocedal},
 title		= {Updating quasi-{N}ewton matrices with limited storage},
 journal	= MC,
 volume		= 35, pages = {773--782}, year = 1980}

@inproceedings{Noce84,
 author		= {J. Nocedal},
 title		= {Trust Region Algorithms for Solving Large Systems of
		   Nonlinear Equations},
 booktitle	= {Innovative Methods for Nonlinear Problems},
 editor		= {W. Liu and T. Belytschko and K. C. Park},
 publisher	= {Pineridge Press},
 pages		= {93--102}, year = 1984,
 abstract	= {We review various algorithms for solving large sparse
		   systems of nonlinear equations, with emphasis in those
		   methods based on trust regions. We consider only those
		   cases when derivatives are available, either analytically
		   or by finite differences. We describe a new algorithm,
		   which is based on minimizing the $\ell_1$-norm of the
		   linearized equations within an $\ell_{\infty}$-norm trust
		   region. The resulting problems are solved by means of
		   sparse linear programming techniques},
 summary	= {Algorithms for solving large sparse systems of
		   nonlinear equations are reviewed, with emphasis on
		   trust-region methods. An algorithm is described in which
		   the $\ell_1$ norm of the linearized
		   equations is minimized within an $\ell_{\infty}$ norm trust
		   region. The resulting subproblems are solved by means of
		   sparse linear programming techniques}}

@inproceedings{Noce86,
 author		= {J. Nocedal},
 title		= {Viewing the Conjugate-Gradient Algorithm as a Trust Region
		   Method},
 booktitle	= {Numerical Analysis},
 editor		= {J. P. Hennart},
 publisher	= SPRINGER, address = SPRINGER-ADDRESS,
 series		= {Lecture Notes in Mathematics}, volume = 1230,
 pages		= {118--126}, year = 1986,
 summary	= {It is shown how a trust-region subproblem, based upon a
		   memoryless secant-updating formula, may be solved very
		   efficiently. A connection is made between such subproblems
		   and the conjugate-gradient method.}}

@article{NoceOver85,
 author		= {J. Nocedal and M. L. Overton},
 title		= {Projected {H}essian updating algorithms for nonlinearly
		   constrained optimization},
 journal	= SINUM,
 volume		= 22, pages = {821--850}, year = 1985}

@inproceedings{NoceYuan98,
 author		= {J. Nocedal and Y. Yuan},
 title		= {Combining trust region and line search techniques},
 crossref	= {Yuan98}, pages = {153--176},
 abstract	= {We propose an algorithm for nonlinear optimization that
		   employs both trust region techniques and line searches.
		   Unlike traditional trust region methods, our algorithm does
		   not resolve the subproblem if the trial step results in an
		   increase in the objective function, but instead performs a
		   backtracking line search from the failed point.
		   Backtracking can be done along a straight line or along a
		   curved path. We show that the new algorithm preserves the
		   strong convergence properties of trust region methods.
		   Numerical results are also presented.},
 summary	= {An algorithm for nonlinear optimization that employs both
		   trust-region techniques and linesearches is proposed. This
		   algorithm does not resolve the subproblem if the trial step
		   results in an increase in the objective function, but
		   instead performs a backtracking linesearch from the failed
		   point. Backtracking can be done along a straight line or
		   along a curved path. It is shown that the algorithm
		   preserves the strong convergence properties of trust-region
		   methods. Numerical results are presented.}}

@article{Nota93,
 author		= {Y. Notay},
 title		= {On the convergence rate of the conjugate gradients in
		   presence of rounding errors},
 journal	= NUMMATH,
 volume		= 65, number = 3, pages = {301--317}, year = 1993}

%%% O %%%

@article{OLea80,
 author		= {D. P. O'Leary},
 title		= {A generalized conjugate gradient algorithm for solving a
		   class of quadratic programming problems},
 journal	= LAA,
 volume		= 34, pages = {371--399}, year = 1980}

@phdthesis{Omoj89,
 author		= {E. O. Omojokun},
 title		= {Trust region algorithms for optimization with nonlinear
		   equality and inequality constraints},
 school		= {University of Colorado},
 address	= {Boulder, Colorado, USA},
 year		= 1989,
 abstract	= {We consider the general nonlinear optimization problem
		   defined as, minimize a nonlinear real-valued function of
		   several variables, subject to a set of nonlinear equality 
		   and inequality constraints.  This class of problems arise
		   in many real life applications, for example in engineering
		   design, chemical equilibrium, simulation and data fitting.
		   In this research, we present algorithms that use the trust
		   region technique to solve these problems.  First, we
		   develop an algorithm for solving the nonlinear equality
		   constrained optimization, then we generalize the algorithm
		   to handle the inclusion of nonlinear inequality constraints
		   in the problem.  The algorithms use the successive
		   quadratic programming (SQP) approach and trust region
		   technique. We define a model subproblem which minimizes 
		   a quadratic approximation of the Lagrangian subject to
		   modified relaxed linearizations of the problem nonlinear
		   constraints and a trust region constraint.  Inequality
		   constraints are handled by a compromise between an active
		   set strategy and IQP subproblem solution technique.  An
		   analysis which describes the local convergence properties of
		   our algorithms is presented.  The algorithms are
		   implemented and the model minimization is done
		   approximately by using the dogleg approach.  Numerical
		   results are presented and compared with the results of a
		   popular linesearch method.  Some examples are presented in
		   which the ability of our method to use directions of
		   negative curvature results in greater reliability.  Results
		   of the numerical experiments indicate that our method is
		   very robust and reasonably efficient.},
 summary	= {Trust-region algorithms for the general nonlinear
		   optimization problem are presented. These handle both the
		   equality and inequality constrained cases. The algorithms
		   use the SQP approach combined with the trust-region
		   technique. A model subproblem is defined in which 
		   a quadratic approximation of the Lagrangian is minimized
		   subject to modified relaxed linearizations of the problem
		   nonlinear constraints and a trust-region constraint.
		   Inequality constraints are handled by a compromise
		   between an active set strategy and IQP subproblem solution
		   techniques.  A local convergence analysis is presented.
		   Numerical tests indicate that the proposed methods are
		   very robust and reasonably efficient.}}

@book{OrteRhei70,
 author		= {J. M. Ortega and W. C. Rheinboldt},
 title		= {Iterative Solution of Nonlinear Equations in Several
		   Variables},
 publisher	= AP, address = AP-ADDRESS,
 year		= 1970}

@article{Osbo76,
 author		= {M. R. Osborne},
 title		= {Nonlinear least squares---the {L}evenberg-{M}arquardt
		   algorithm revisited},
 journal	= {Journal of the Australian Mathematical Society, Series B},
 volume		= 19, pages = {343--357}, year = 1976,
 summary	= {A rule for choosing the Levenberg-Morrison-Marquardt
		   parameter is described, which permits a satisfactory
		   convergence theorem to be proved, and is capable of
		   satisfactory computer implementation.}}

@book{Osbo85,
 author		= {M. R. Osborne},
 title		= {Finite Algorithms for Optimization and Data Analysis},
 publisher	= WILEY, address = WILEY-ADDRESS,
 year		= 1985}

@article{Osbo87,
 author		= {M. R. Osborne},
 title		= {Estimating nonlinear models by maximum likelihood for the
		   exponential family},
 journal	= SISSC,
 volume		= 8, number = 3, pages = {446--456}, year = 1987,
 abstract	= {Many but not all attractive properties of generalized
		   linear models associated with the exponential family of
		   distributions are destroyed by nonlinearity. A consequence
		   is that ensuring the stability of a computational process
		   for maximizing the likelihood becomes relatively more
		   important. Here it is shown that trust region methods for
		   solving nonlinear least squares problems are readily
		   adapted to maximize likelihoods based on the exponential
		   family, and that the nice theoretical results available for
		   the nonlinear least squares problem also generalize.},
 summary	= {Trust-region methods for solving nonlinear
		   least-squares problems are  adapted to maximize
		   likelihoods based on the exponential family, while
		   preserving their theoretical properties.}}

@techreport{Osbo98,
 author		= {M. R. Osborne},
 title		= {Variable selection and control in least squares problems},
 institution	= {Centre for Mathematics and its Applications,
                   School of Mathematical Sciences, 
                   Australian National University},
 address	= {Canberra, Australia},
 number		= {MRR 047-98}, year = 1998,
 abstract	= {The classical technique of stepwise regression provides a
		   paradigm for variable selection in the linear least squares
		   problem. Trust region method which control the size of the
		   correction to the current solution estimate prove
		   attractive for nonlinear least squares problems because of
		   their good global convergence behaviour. Recently there has
		   been a convergence of these techniques with the realisation
		   that the $\ell_1$ trust region method also provides a form
		   of variable selection. These results are reviewed here, and
		   computational methods discussed.},
 summary	= {Results are reviewed showing that the $\ell_1$ trust-region
		   method provides a form of variable selection for
		   least-squares problems and computational methods are
		   discussed.}}

@techreport{OutrZoweSchr91,
 author		= {J. Outrata and J. Zowe and H. Schramm},
 title		= {Bundle trust methods: {F}ortran codes for nondifferentiable
		   optimization},
 institution	= {DFG}, address = {Germany},
 number		= 269, year = 1991}

%%% P %%%

@phdthesis{Paig71,
 author		= {C. C. Paige},
 title		= {The computation of eigenvalues and eigenvectors of very
		   large sparse matrices},
 school		= {University of London},
 year		= 1971}

@article{PaigSaun75,
 author		= {C. C. Paige and M. A. Saunders},
 title		= {Solution of sparse indefinite systems of linear equations},
 journal	= SINUM,
 volume		= 12, number = 4, pages = {617--629}, year = 1975}

@article{PaigSaun82a,
 author		= {C. C. Paige and M. A. Saunders},
 title		= {{LSQR}: an algorithm for sparse linear equations and sparse
		   least squares},
 journal	= TOMS,
 volume		= 8, pages = {43--71}, year = 1982}

@article{Pang81,
 author 	= {J. S. Pang},
 title  	= {An equivalence between two algorithms for quadratic
		   programming},
 journal 	= MP,
 volume 	= 20, number = 2, pages = {152--165}, year = 1981}

@inproceedings{Pang95,
 author		= {J. S. Pang},
 title		= {Complementarity problems},
 booktitle	= {Handbook of Global Optimization},
 editor		= {R. Horst and P. Pardalos},
 publisher	= KLUWER, address = KLUWER-ADDRESS,
 pages		= {271--338}, year = 1995}

@article{PaniTits91,
 author		= {E. Panier and A. L. Tits},
 title		= {Avoiding the {M}aratos effect by means of a nonmonotone
		   linesearch {I}. General constrained problems},
 journal	= SINUM,
 volume		= 28, pages = {1183--1195}, year = 1991}

@article{Pant88,
 author		= {J. F. A. Pantoja},
 title		= {Differential dynamic-programming and {N}ewton method},
 journal	= {International Journal of Control},
 volume		= 47, number = 5, pages = {1539-1553}, year = 1988}

@article{PantMayn91,
 author		= {J. F. A. Pantoja and D. Q. Mayne},
 title		= {Exact penalty functions with simple updating of the penalty
		   parameter},
 journal	= JOTA,
 volume		= 69, pages = {441--467}, year = 1991}

@book{PapaStei82,
 author		= {C. H. Papadimitriou and K. Steiglitz},
 title		= {Combinatorial Optimization},
 publisher	= PH, address = PH-ADDRESS,
 year		= 1982}

@book{Parl80,
 author		= {B. N. Parlett},
 title		= {The Symmetric Eigenvalue Problem},
 publisher	= PH, address = PH-ADDRESS,
 year		= 1980,
 note           = {Reprinted as \emph{Classics in Applied Mathematics 20}, SIAM,
		   Philadelphia, USA, 1998}}

@article{ParlReid81,
 author		= {B. N. Parlett and J. K. Reid},
 title		= {Tracking the progress of the {L}anczos algorithm for large
		   symmetric eigenproblems},
 journal	= JIMA,
 volume		= 1, pages = {135--155}, year = 1981}

@book{Patr94,
 author		= {M. Patriksson},
 title		= {The Traffic Assignment Problem: Models and Methods},
 publisher	= {VSP}, address = {Utrecht, The Netherlands},
 year		= 1994}

@book{Patr98,
 author		= {M. Patriksson},
 title		= {Nonlinear Programming and Variational Inequality Problems,
		   a Unified Approach},
 publisher	= KLUWER, address = KLUWER-ADDRESS,
 year		= 1998}

@article{Peng96,
 author		= {J. Peng},
 title		= {Unconstrained Methods for generalized nonlinear
		   complementarity and variational inequality problems},
 journal	= JCM,
 volume		= 14, number = 2, pages = {99--107}, year = 1996,
 abstract	= {In this paper, we construct unconstrained methods for the
		   generalized nonlinear complementarity problem and
		   variational inequalities. Properties of the correspondent
		   unconstrained optimization problem are studied. We apply
		   these methods to the subproblems in trust region method,
		   and study their interrelationships. Numerical results are
		   also presented.},
 summary	= {Unconstrained methods for the generalized nonlinear
		   complementarity problem and variational inequalities are
		   constructed. Properties of the corresponding unconstrained
		   optimization problem are studied. These methods are applied
		   to the subproblems in trust-region methods, and their
		   interrelationships studied. Numerical results are
		   presented.}}

@inproceedings{Peng98,
 author		= {J. Peng},
 title		= {A Smoothing Function and Its Applications},
 crossref	= {FukuQi98}, pages = {293--316}}

@article{PengYuan97,
 author		= {J. Peng and Y. Yuan},
 title		= {Optimality conditions for the minimization of a quadratic
		   with two quadratic constraints},
 journal	= SIOPT,
 volume		= 7, number = 3, pages = {579--594}, year = 1997,
 abstract	= {The trust region method has been proven to be very
		   successful in both unconstrained and constrained
		   optimization. It requires the global minimum of a general
		   quadratic function subject to ellipsoid constraints. In
		   this paper, we generalize the trust region subproblem by
		   allowing two general quadratic constraints. Conditions and
		   properties of its solution are discussed.},
 summary	= {The trust region subproblem is generalized by allowing two
		   general quadratic constraints. Conditions and properties of
		   its solution are discussed.}}

@techreport{Perr76,
 author		= {A. Perry},
 title		= {A modified conjugate gradient algorithm},
 institution	= {Center for Mathematical Studies in Economics and Management
		   Science, Northwestern University},
 address	= NWU-ADDRESS,
 number		= 229, year = 1976}

@article{PetzRenMaly97,
 author		= {L. R. Petzold and Y. H. Ren and T. Maly},
 title		= {Regularization of higher-index differential-algebraic
		   equations with rank-deficient constraints},
 journal	= SISC,
 volume		= 18, number = 3, pages = {753--774}, year = 1997,
 abstract	= {In this paper we present several regularizations for
		   higher-index differential-algebraic equations with
		   rank-deficient or singular constraints. These types of
		   problems arise, for example, in the solution of constrained
		   mechanical systems, when a mechanism's trajectory passes
		   through or near a kinematic singularity. We derive a class
		   of regularizations for these problems which is based on
		   minimization of the norm of the constraints. The new
		   regularizations are analogous to trust-region methods of
		   numerical optimization. We give convergence results for the
		   regularizations and present some numerical experiments
		   which illustrate their effectiveness.},
 summary	= {Several regularizations for higher-index
		   differential-algebraic equations with rank-deficient or
		   singular constraints are presented. These types of problems
		   arise in the solution of constrained mechanical systems,
		   when a mechanism's trajectory passes through or near a
		   kinematic singularity. Regularizations for these
		   problems are derived which are based on minimization of the
		   norm of the constraints. They are analogous to trust-region
		   methods. Convergence results are given and numerical
		   experiments are presented.}}

@article{PhamWangYass90,
 author		= {Pham Dinh, T. and S. Wang},
 title		= {Training multi-layered neural network with a trust-region
		   based algorithm},
 journal	= RAIRO-MM,
 volume		= 24, number = 4, pages = {523--553}, year = 1990,
 abstract	= {In this paper, we first show how the problem of training a
		   neural network is modelized as an optimization problem; and
		   the generally used training algorithm. Then we propose a
		   new algorithm based on a trust-region technique which is
		   very efficient for non-convex optimization problems.
		   Experimental results show that the new algorithm is much
		   faster and robust compared with GBP. It makes the design of
		   neural net architecture much less problem-dependent.},
 summary	= {The problem of training a neural network is modelled as an
		   optimization problem and gradient backpropagation, the most
		   commonly used training method, is described. A 
		   trust-region algorithm is then proposed. Experimental
		   results show that the algorithm is much faster and
		   robust compared with gradient backpropagation. It makes the
		   design of neural net architecture much less
		   problem-dependent.}}

@article{PhamHoai95,
 author		= {Pham Dinh, T. and Le Thi, H. A.},
 title		= {{L}agrangian stability and global optimality on nonconvex
		   quadratic minimization over {E}uclidean balls and spheres},
 journal	= {Journal of Convex Analysis},
 volume		= 2, number = {1--2}, pages = {263--276}, year = 1995,
 abstract	= {We prove in this paper the stability of the Lagrangian
		   duality in nonconvex quadratic minimization over Euclidean
		   balls and spheres. As direct consequences we state both
		   global optimality conditions in these problems and detailed
		   descriptions of the structure of their solution sets. These
		   results are essential for devising solution algorithms.},
 summary	= {Stability of the Lagrangian duality in non-convex quadratic
		   minimization over Euclidean balls and spheres is proved.
		   Global optimality conditions for these problems are deduced
		   together with the detailed descriptions of the structure of
		   their solution sets.}}

@article{PhamHoai98,
 author		= {Pham Dinh, T. and Le Thi, H. A.},
 title		= {{D.C.} optimization algorithm for solving the trust-region
		   subproblem},
 journal	= SIOPT,
 volume		= 8, number = 2, pages = {476--505}, year = 1998,
 abstract	= {This paper is devoted to the framework of d.c. (difference
		   of convex functions) optimization: d.c. duality, local and
		   global optimalities in d.c. programming, the d.c. algorithm
		   (DCA) and its application to solving the trust-region
		   problem. The DCA is an iterative method which is quite
		   different from well-known related algorithms. Thanks to the
		   particular structure of the problem, the DCA becomes very
		   simple (it requires only matrix-vector products) and, in
		   practice, converges to a global solution. For checking the
		   global optimality of solutions provided by the DCA the
		   quite inexpensive Implicitly Restarted Lanczos method of
		   Sorensen has been used. A simple numerical procedure has
		   been introduced (in the case of nonglobal solutions) in
		   order to find a feasible point having a smaller objective
		   value and to restart the DCA with this point. It has been
		   stated that in the nonconvex case (problem ($Q_1$) with $A$
		   being nonpositive semidefinite) the DCA with at most $2m+2$
		   restartings ($m$ is the number of distinct negative
		   eigenvalues of $A$) requires only matrix-vector products
		   too and converges to a global solution. Numerical
		   simulations proved the robustness and the efficiency of the
		   DCA with respect to related standard methods, especially in
		   large scale problems.},
 summary	= {The framework of d.c. (difference of convex functions)
		   optimization is presented, including d.c. duality, local
		   and global optimality, the d.c. algorithm (DCA) and its
		   application to solving the trust-region problem, which only
		   requires matrix-vector products. In practice, it converges
		   to a global solution, which is checked by using the
		   Implicitly Restarted Lanczos method of Sorensen. If a
		   nonglobal solution is found, a procedure is proposed, that
		   finds a feasible point having a smaller objective value at
		   which the DCA may then be restarted. It is proved that, in
		   the non-convex case, the DCA needs at most $2m+2$ restarts
		   to converge to a global solution, where $m$ is the number
		   of distinct negative eigenvalues of the Hessian. The
		   robustness and efficiency of the DCA is illustrated by
		   numerical experiments.}}

@article{PhamPhonHoraQuan97,
 author		= {Pham Dinh, T. and T. Q. Phong and R. Horaud and L. Quan},
 title		= {Stability of {L}agrangian duality for nonconvex quadratic
		   programming. Solution methods and applications in computer
		   vision},
 journal	= RAIRO-MM,
 volume		= 31, number = 1, pages = {57--90}, year = 1997,
 abstract	= {The problem of minimizing a quadratic form over a ball
		   centered at the origin is considered. The stability of
		   Lagrangian duality is established and complete
		   characterizations of a global optimal solution are given.
		   On the basis of this theoretical study, two principal
		   solution methods are presented. An important application of
		   nonconvex quadratic programming is the computation of rite
		   step to a new iterate in the Trust Region (TR) approach
		   methods which are known to be efficient for nonlinear
		   optimization problems. Also, we discuss the mathematical
		   models of some important problems encountered in Computer
		   Vision. Most of them can be formulated as a minimization of
		   a sum of squares of nonlinear functions. A practical
		   TR-based algorithm is proposed for nonlinear least squares
		   problem which seems to be well suited for our applications.},
 summary	= {The problem of minimizing a quadratic form over a ball is
		   considered. The stability of Lagrangian duality is
		   established and complete characterizations of a global
		   optimal solution are given. Two solution methods
		   are deduced, with application to the trust-region
		   subproblem. Mathematical models of some important problems
		   encountered in computer vision are discussed, which
		   can be formulated as a minimization of a sum of squares of
		   nonlinear functions. A practical trust-region based
		   algorithm is proposed for the nonlinear least-squares problem
		   which seems to be well suited to the computer vision
		   applications.}}

@article{Phan82,
 author         = {Phan huy Hao, E.},
 title          = {Quadratically constrained quadratic programming: some
                   applications and a method for solution},
 journal        = {Zeitschrift f\"{u}r Operations Research},
 volume         = 26, number = 3, pages = {105--119}, year = 1982,
 abstract       = {(no abstract)},
 summary        = {A method is proposed for the solution of quadratically
                   constrained quadratic programming.}}

@inproceedings{PhonHoraYassPham93,
 author         = {T. Q. Phong and R. Horaud and A. Yassine and Pham Dinh, T.},
 title          = {Optimal estimation of object pose from a single perspective 
                   view},
 booktitle      = {1993 Proceedings Fourth International Conference on 
                   Computer Vision},
 publisher      = {IEEE Computer Society Press}, 
 address        = {Los Alamitos, CA, USA},
 pages          = {534--539}, year = 1993,
 abstract       = {The authors present a method for robustly and
                   accurately estimating the rotation and translation
                   between a camera and a 3-D object from point and line
                   correspondences. First they devise an error function
                   and then show how to minimize this error
                   function. The quadratic nature of this function is
                   made possible by representing rotation and
                   translation with a dual number quaternion. A detailed
                   account is provided of the computational aspects of a
                   trust-region optimization method. This method
                   compares favourably with Newton's method, which has
                   extensively been used to solve the problem, and with
                   Faugeras-Toscani's linear method (1986) for
                   calibrating a camera. Some experimental results are
                   presented which demonstrate the robustness of the
                   method with respect to image noise and matching
                   errors.},
 summary        = {A method for robustly and
                   accurately estimating the rotation and translation
                   between a camera and a 3-D object from point and line
                   correspondences. An error function is defined
                   and then minimized. The quadratic nature of this function is
                   made possible by representing rotation and
                   translation with a dual number quaternion. A detailed
                   account is provided of the computational aspects of a
                   trust-region optimization method. This method
                   compares favourably with Newton's method, which has
                   extensively been used to solve the problem, and with
                   Faugeras-Toscani's linear method (1986) for
                   calibrating a camera. Experimental results are
                   presented which demonstrate the robustness of the
                   method with respect to image noise and matching
                   errors.}}


@article{PhonHoraYassPham95,
 author		= {T. Q. Phong and R. Horaud and A. Yassine and Pham Dinh, T.},
 title		= {Object pose from 2-D to 3-D Point and Line Correspondences},
 journal	= {International Journal of Computer Vision},
 volume		= 15, number = 3, pages = {225--243}, year = 1995,
 abstract	= {In this paper we present a method for optimally estimating
		   the rotation and translation between a camera and a 3-D
		   object from point and/or line correspondences. First we
		   devise an error function and second we show how to minimize
		   this error function. The quadratic nature of this function
		   is made possible by representing rotation and translation
		   with a dual number quaternion. We provide a detailed
		   account of the computational aspects of a trust-region
		   optimization method. This method compares favourably with
		   Newton's method which has extensively been used to solve
		   the problem at hand, with the Faugeras-Toscani linear
		   method for calibrating a camera, and with the
		   Levenberg-Marquardt non-linear optimization method. Finally
		   we present some experimental results which demonstrate the
		   robustness of our method with respect to image noise and
		   matching errors.},
 summary	= {A method for optimally estimating the rotation and
		   translation between a camera and a 3-D object from point
		   and/or line correspondences is presented. An error function
		   is devised. The quadratic nature of the error function is
		   obatined by representing rotation and translation with a
		   dual number quaternion. We provide a detailed account of
		   the computational aspects of a trust-region optimization
		   method to minimize the error. This method compares
		   favourably with Newton's method, with the Faugeras-Toscani
		   linear method for calibrating a camera, and with the
		   Levenberg-Morrison-Marquardt nonlinear optimization method.
		   Experimental results demonstrate the robustness of the
		   method with respect to image noise and matching errors.}}

@inproceedings{PiepMcMuLipk98,
 author         = {J. A. Piepmeier and G. V. McMurray and H. Lipkin},
 title          = {Tracking a moving target with model independent visual 
                   servoing: a predictive estimation approach},
 booktitle      = {Proceedings 1998 IEEE International Conference on Robotics 
                   and Automation},
 publisher      = {IEEE}, address = {New York, NY, USA}, 
 volume         = 3, pages = {2652--2657}, year = 1998,
 abstract       = {Target tracking by model independent visual servo
                   control is achieved by augmenting quasi-Newton trust
                   region control with target prediction. Model
                   independent visual servo control is defined using
                   visual feedback to control the robot without precise
                   kinematic and camera models. While a majority of the
                   research assumes a known robot and camera model,
                   there is a paucity of literature addressing model
                   independent control. In addition, most researches
                   have focused primarily on static targets. The work
                   presented here demonstrates the use of predictive
                   filters to improve the performance of the control
                   algorithm for linear and circular target motions. The
                   results show a performance of the same order of
                   magnitude as compared to some model based visual
                   servo control research. Certain limitations to the
                   algorithm are also discussed.},
 summary        = {Target tracking by model independent visual servo
                   control is achieved by augmenting quasi-Newton trust-region
		   control with target prediction. Model independent visual
		   servo control is defined using visual feedback to control
		   the robot without precise kinematic and camera models.  The
		   use of predictive filters to improve the performance of the
		   control algorithm for linear and circular target motions is
		   demonstrated. The results show a performance of the same
		   order of magnitude as compared to some model based visual
                   servo control research. Certain limitations to the
                   algorithm are also discussed.}}

@article{Piet69,
 author		= {T. Pietrzykowski},
 title		= {An Exact Potential Method for Constrained Maxima},
 journal	= SINUM,
 volume		= 6, number = 2, pages = {299--304}, year = 1969}
%abstract 	= {The main result of the paper consists of the theorem that
%            	   under certain, natural assumptions the local conditional
%           	   maximum $x_0$ of the function $f$ on the set \[A = \{x\in
%           	   \Re^n | \phi_i(x)\geq 0, \psi_j(x) = 0, i=1,\ldots,
%           	   k,j=1,\ldots,l\}\] is identical with the unconditional
%        	   maximum of the potential function \[p(x,\mu) = \mu f(x) +
%        	   \sum_{i=1}^k \neg(\phi_i(x))- \sum_{j=1}^l | \psi(x)|,
%        	   x\in \Re^n, \mu \geq 0,\] for $\mu$ sufficiently small.
%                  There is also provided a draft of a modified gradient
%                  procedure for maximizing the potential $p(x,\mu)$ since
%                  it is generally nonsmooth even for differentiable 
%                  $f, \phi_i$ and $\psi_j$.},
%summary  	= {This paper  presents a theorem that under certain, natural 
%                  assumptions the local conditional maximum $x_0$ of the
%          	   function $f$ on the set $A = \{x\in \Re^n | \phi_i(x)\geq 0,
%       	   \psi_j(x) = 0, i=1,\ldots, k,j=1,\ldots,l\}$ is identical
%        	   with the unconditional maximum of the potential function
%         	   $p(x,\mu) = \mu f(x) + \sum_{i=1}^k \neg(\phi_i(x))-
%          	   \sum_{j=1}^l | \psi(x)|, x\in \Re^n, \mu \geq 0,$ for $\mu$
%          	   sufficiently small.  In addition an outline of a modified
%          	   gradient procedure for maximizing the potential $p(x,\mu)$
%          	   is given.  The modification is necessary since the
%          	   potential function is generally non-smooth even for
%          	   differentiable $f, \phi_i$ and $\psi_j$.}}

@article{Plan99,
 author		= {T. D. Plantenga},
 title		= {A trust-region method for nonlinear programming based on
		   primal interior point techniques},
 journal	= SISC,
 volume		= 20, number = 1, pages = {282--305}, year = 1999,
 abstract	= {This paper describes a new trust region method for solving
		   large-scale optimization problems with nonlinear equality
		   and inequality constraints. The new algorithm employs
		   interior-point techniques from linear programming, adapting
		   them for more general nonlinear problems. A software
		   implementation based entirely on sparse matrix methods is
		   described. The software handles infeasible start points,
		   identifies the active set of constraints at a solution, and
		   can use second derivative information to solve problems.
		   Numerical results are reported for large and small
		   problems, and a comparison made with other large-scale
		   codes.},
 summary	= {A trust region method for large-scale optimization
		   problems with nonlinear equality and inequality constraints
		   is described. The algorithm employs interior-point
		   techniques from linear programming, adapting them for more
		   general nonlinear problems. A software implementation based
		   entirely on sparse matrix methods is described. The
		   software handles infeasible start points, identifies the
		   active set of constraints at a solution, and can use second
		   derivative information. Numerical results are reported for
		   large and small problems, and a comparison made with other
		   large-scale codes.}}

@book{Pola97,
 author         = {E. Polak},
 title          = {Optimization. Algorithms and Consistent Approximations},
 publisher      = SPRINGER, address = SPRINGER-ADDRESS,
 series         = {Applied Mathematical Sciences, Volume 124},
 year           = 1997}

@article{PolaTits80,
 author		= {E. Polak and A. L. Tits},
 title		= {A globally convergent implementable multiplier method with
		   automatic penalty limitation},
 journal	= {Applied Mathematics and Optimization},
 volume		= 6, pages = {335--360}, year = 1980}

@article{PoliQi95,
 author		= {R. Poliquin and L. Qi},
 title		= {Iteration Functions in some nonsmooth optimization
		   algorithms},
 journal	= MOR,
 volume		= 20, number = 2, pages = {479--496}, year = 1995,
 abstract	= {Recently, several globally convergent model algorithms
		   based on iteration functions have been proposed for solving
		   nonsmooth optimization problems. In particular,
		   \citebb{PangHanRang91} proposed such an algorithm for
		   minimizing a locally Lipschitzian function. We determine
		   properties of iteration functions (calculus, existence); we
		   also identify characteristics of functions that possess
		   iteration functions. We show that a locally Lipschitzian
		   function has a Pang-Han-Rangaraj iteration function only
		   when the function is pseudo-regular (in the sense of
		   Borwein), and that a subsmooth (lower-C-1)function always
		   has a Pang-Han-Rangaraj iteration function.},
 summary	= {Properties of iteration functions (calculus, existence)
		   arising in model trust-region algorithms for non-smooth
		   problems are analyzed. It is shown that a locally
		   Lipschitzian function has a Pang-Han-Rangaraj iteration
		   function only when the function is pseudo-regular (in the
		   sense of Borwein), and that a sub-smooth (lower-C-1)
		   function always has a Pang-Han-Rangaraj iteration function.}}

@article{PoljWolk95,
 author		= {S. Poljack and H. Wolkowicz},
 title		= {Convex relaxations of (0, 1)--Quadratic Programming},
 journal	= MOR,
 volume		= 20, number = 3, pages = {550--561}, year = 1995}

@article{PoljRendWolk95,
 author		= {S. Poljack and F. Rendl and H. Wolkowicz},
 title		= {A recipe for semidefinite relaxation for (0,1)--quadratic
		   programming},
 journal	= {Journal of Global Optimization},
 volume		= 7, number = 1, pages = {51--73}, year = 1995,
 abstract	= {We review various relaxations of (0,1)-quadratic
		   programming problems. These include semidefinite programs,
		   parametric trust region problems and concave quadratic
		   maximization. All relaxations that we consider lead to
		   efficiently solvable problems. The main contributions of
		   the paper are the following. Using Lagrangian duality, we
		   prove equivalence of the relaxations in a unified and
		   simple way. Some of these equivalences have been known
		   previously, but our approach leads to short and transparent
		   proofs. Moreover we extend the approach to the case of
		   equality constraints into the objective function. We show
		   how this technique can be applied to the Quadratic
		   Assignment Problem, the Graph Partition Problem and the
		   Max-Clique Problem. Finally, we show our relaxation to be
		   best possible among all quadratic majorants with zero
		   trace.},
 summary	= {Various relaxations of (0,1)-quadratic programming problems
		   are reviewed, including semidefinite programs, parametric
		   trust-region problems and concave quadratic maximization.
		   All lead to efficiently solvable problems. Using Lagrangian
		   duality, equivalence of the relaxations is proved in a
		   unified way. The approach is extended to the case where
		   equality constraints are present. It is shown how this
		   technique can be applied to the Quadratic Assignment
		   Problem, the Graph Partition Problem and the Max-Clique
		   Problem. The relaxation is the best possible
		   among all quadratic majorants with zero trace.}}

@article{Poly69,
 author		= {B. T. Polyak},
 title		= {The conjugate gradient method in extremal problems},
 journal	= {U.S.S.R. Computational Mathematics and Mathematical Physics},
 volume		= 9, pages = {94--112}, year = 1969}

@misc{Poly82,
 author		= {R. Polyak},
 title		= {Smooth optimization methods for solving nonlinear extremal
		   and equilibrium problems with constraints},
 howpublished	= {Presentation at the IXth International Symposium on
		   Mathematical Programming, Bonn},
 month		= {August}, year = 1982}

@article{Poly90,
 author		= {R. Polyak},
 title		= {Modified barrier functions (theory and methods)},
 journal	= MP,
 volume		= 54, number = 2, pages = {177--222}, year = 1992}

@phdthesis{Ponc90,
 author		= {D. B. Poncele\'{o}n},
 title		= {Barrier methods for large-scale quadratic programming},
 school		= STANFORD, address = STANFORD-ADDRESS,
 year		= 1990}

@inproceedings{PornFichMullZapf90,
 author         = {F. Pornbacher and U. Fichter and G. Muller-Liebler
                   and H. Zapf},
 title          = {A new method for an efficient optimization of MOS 
                   transistor models},
 booktitle      = {1990 IEEE International Symposium on Circuits
		    and Systems},
 publisher      = {IEEE}, address = {New York, USA}, 
 volume         = 1, pages = {81--84}, year = 1990,
 abstract       = {Two methods that are especially useful for an
                   accurate optimization of complex transistor models
                   are presented. The first method focuses on sample
                   reduction before the optimization process. An
                   algorithm is described which allows a reduction of
                   the number of samples by a factor of 10 to 20 in an
                   efficient way. The second method is a
                   trust-region-type optimization algorithm which is
                   especially designed for this application. A
                   substantial part of it is a new algorithm for the
                   calculation of the step length. Industrial examples
                   demonstrating the quality of the algorithms are
                   given.},
 summary        = {Two methods are described for accurate
                   optimization of complex transistor models.
                   The first focuses on sample reduction before the
		   optimization process. An algorithm is described which
		   allows a reduction of the number of samples by a factor
		   of 10 to 20. The second method is a trust-region-type
		   optimization algorithm which is especially designed for
		   this application. Industrial examples
                   demonstrate the quality of the algorithms.}}


@inproceedings{Powe69,
 author		= {M. J. D. Powell},
 title		= {A method for nonlinear constraints in minimization problems},
 crossref	= {Flet69}, pages = {283--298}}

@inproceedings{Powe70a,
 author		= {M. J. D. Powell},
 title		= {A New Algorithm for Unconstrained Optimization},
 crossref	= {RoseMangRitt70}, pages = {31--65},
 abstract	= {A new algorithm is described for calculating the least
		   value of a given differentiable function of several
		   variables. The user must program the evaluation of the
		   function and its first derivatives. Some convergence
		   theorems are given that impose very mild conditions on the
		   objective function. These theorems, together with some
		   numerical results, indicate that the new method may be
		   preferable to current algorithms for solving many
		   unconstrained minimization problems.},
 summary	= {A trust-region algorithm is described for unconstrained
		   smooth minimization. Convergence theorems are given that
		   impose very mild conditions on the objective function.
		   These theorems, together with some numerical results,
		   indicate that the method may be preferable to then current
		   algorithms for solving unconstrained minimization problems.}}

@techreport{Powe70b,
 author		= {M. J. D. Powell},
 title		= {A {F}ortran Subroutine for Unconstrained Minimization
		   Requiring First Derivatives of The Objective Function},
 institution	= HARWELL, address = HARWELL-ADDRESS,
 number		= {R-6469}, year = 1970,
 summary	= {Details of the implementation of the algorithm described in
		   \citebb{Powe70a} are provided and numerical experiments are
		   discussed. The Fortran code is given in appendix.}}

@inproceedings{Powe70c,
 author		= {M. J. D. Powell},
 title		= {A hybrid method for nonlinear equations},
 crossref	= {Rabi70}, pages = {87--114},
 summary	= {An algorithm for solving systems of nonlinear equations is
		   described that does not require the evaluation of the
		   Jacobian of the system. Instead, the derivatives are
		   approximated by Broyden's quasi-Newton formula. The
		   algorithm uses a Levenberg-Morrison-Marquardt procedure for
		   computing a new iterate, together with a safeguarding
		   technique that prevents any tendencies towards linear
		   independence of steps. Convergence of the algorithm is
		   proved to either a solution of the system or a local
		   minimum of the norm of its residual. }}

@inproceedings{Powe70d,
 author		= {M. J. D. Powell},
 title		= {A {F}ortran subroutine for solving systems of nonlinear
		   algebraic equations},
 crossref	= {Rabi70}, pages = {115--161},
 summary	= {Details of the implementation of the algorithm described in
		   \citebb{Powe70c} are provided and numerical experiments are
		   discussed. The Fortran code is given in appendix.}}

@inproceedings{Powe75,
 author		= {M. J. D. Powell},
 title		= {Convergence Properties of a Class of Minimization
		   Algorithms},
 crossref	= {MangMeyeRobi75}, pages = {1--27}}
 abstract	= {Many iterative algorithms for minimizing a function
		   $F(x)=F(x_1,x_2\ldots,x_n)$ require first derivatives of
		   $F(x)$ to be calculated, but they maintain an approximation
		   to the second derivative matrix automatically. In order
		   that the approximation is useful, the change in $x$ made by
		   each iteration is subject to a bound that is also revised
		   automatically. Some convergence theorems for a class of
		   minimization algorithms of this type are presented, which
		   apply to methods proposed by \citebb{Powe70a} and
		   \citebb{Flet72}. This theory has the following three
		   valuable features which are rather uncommon. There is no
		   need for the starting vector $x_1$ to be close to the
		   solution. The function $F(x)$ need not be convex.
		   Superlinear convergence is proved even though the second
		   derivative approximations may not converge to the true
		   second derivatives at the solution.},
 summary	= {Some convergence theorems are presented for a class of
                   minimization algorithms including methods proposed by
		   \citebb{Powe70a} and \citebb{Flet72}.
		   There is no need for the starting vector $x_1$ to
		   be close to the solution. The function $f$ need not be
		   convex. Superlinear convergence is proved even though the
		   second derivative approximations may not converge to the
		   true second derivatives at the solution.}}

@inproceedings{Powe78,
 author		= {M. J. D. Powell},
 title		= {A Fast Algorithm For Nonlinearly Constrained Optimization
		   Calculations},
 crossref	= {Wats78}, pages = {144--157}}

@inproceedings{Powe81,
 author    	= {M. J. D. Powell},
 title     	= {An upper triangular matrix method for quadratic programming},
 editor    	= {O. L. Mangasarian and R. R. Meyer and S. M. Robinson},
 booktitle 	= {Nonlinear Programming, 2},
 publisher 	= AP, address   = AP-ADDRESS,
 year      	= 1981}

@book{Powe81b,
 author		= {M. J. D. Powell},
 title		= {Approximation Theory and Methods},
 publisher	= CUP, address = CUP-ADDRESS,
 year		= 1981}

@techreport{Powe83,
 author		= {M. J. D. Powell},
 title		= {General algorithms for discrete nonlinear approximation
		   calculations},
 institution	= DAMTP, address = DAMTP-ADDRESS,
 number		= {DAMTP/NA2}, year = 1983}

@article{Powe84,
 author		= {M. J. D. Powell},
 title		= {On the global convergence of trust region algorithms for
		   unconstrained minimization},
 journal	= MP,
 volume		= 29, number = 3, pages = {297--303}, year = 1984,
 abstract	= {Many trust region algorithms for unconstrained optimization
		   have excellent global convergence properties if their
		   second derivative approximations are not too large
		   (\bciteb{Powe75}). We consider how large these
		   approximations have to be, if they prevent convergence when
		   the objective function is bounded below and continuously
		   differentiable. Thus we obtain a useful convergence result
		   in the case when there is a bound on the second derivative
		   approximations that depends linearly on the iteration
		   number.},
 summary	= {Global convergence for trust-region methods in
		   unconstrained optimization is obtained in the case when
		   there is a bound on the Hessian approximations that depends
		   linearly on the iteration number.}}

@article{Powe85,
 author 	= {M. J. D. Powell},
 title  	= {On the quadratic-programming algorithm of
		   {G}oldfarb and {I}dnani},
 journal 	= MPS,
 volume 	= 25, pages = {46--61}, year = 1985}

@inproceedings{Powe87,
 author		= {M. J. D. Powell},
 title		= {Methods for Nonlinear Constraints in Optimization
		   Calculations},
 crossref	= {IserPowe87}, pages = {325--358}}

@inproceedings{Powe93,
 author		= {M. J. D. Powell},
 title		= {Log barrier methods for semi-infinite programming
		   calculations},
 booktitle	= {Advances on Computer Mathematics and its Applications},
 editor		= {E. A. Lipitakis},
 publisher	= WSP, address = WSP-ADDRESS,
 pages		= {1--21}, year = 1993}

@inproceedings{Powe94a,
 author		= {M. J. D. Powell},
 title		= {A direct search optimization method that models the
		   objective and constraint functions by linear interpolation},
 crossref	= {GomeHenn94}, pages = {51--67}}

@misc{Powe94b,
 author		= {M. J. D. Powell},
 title		= {A direct search optimization method that models the
		   objective by quadratic interpolation},
 howpublished	= {Presentation at the 5th Stockholm Optimization Days,
		   Stockholm},
 year		= 1994}

@misc{Powe96,
 author		= {M. J. D. Powell},
 title		= {Trust region methods that employ quadratic interpolation to
		   the objective function},
 howpublished	= {Presentation at the 5th SIAM Conference on Optimization,
		   Victoria},
 year		= 1996}
                   
@inproceedings{Powe98,
 author		= {M. J. D. Powell},
 title		= {The use of band matrices for second derivative
		   approximations in trust region algorithms},
 crossref	= {Yuan98}, pages = {3--28},
 abstract	= {In many trust region algorithms for optimization
		   calculations, each iteration seeks a vector $d \in \Re^n$
		   that solves the linear system of equations $(B+\lambda I)
		   d=- g$, where $B$ is a symmetric estimate of a second
		   derivative matrix, $I$ is the unit matrix, $g$ is a known
		   gradient vector, and $\lambda$ is a parameter that controls
		   the length of $d$. Several values of $\lambda$ may be tried
		   on each iteration, and, when there is no helpful sparsity
		   in $B$, it is usual for each solution to require $O(n^3)$
		   operations. However, if an orthogonal matrix $\Omega$ is
		   available such that $M=\Omega^T B \Omega$ is an $n \times
		   n$ matrix of bandwidth $2s+1$, then $\Omega^Td$ can be
		   calculated in only $O(ns^2)$ operations for each new
		   $\lambda$ by writing the system in the form $(M + \lambda
		   I)(\Omega^Td=- \Omega^Tg$. We find unfortunately, that the
		   construction of $M$ and $\Omega$ from $B$ is usually more
		   expensive than the solution of the original system, but in
		   variable metric and quasi-Newton algorithms for
		   unconstrained optimization, each iteration changes $B$ by a
		   matrix whose rank is at most two, and then updating
		   techniques can be applied to $\Omega$. Thus it is possible
		   to reduce the average work per iteration from $O(n^3)$ to
		   $O(n^{7/3})$ operations. Here the elements of each
		   orthogonal matrix are calculated explicitly, but instead
		   one can express the orthogonal matrix updates as products
		   of Givens rotations, which allows the average work per
		   iteration to be only $O(n^{11/5})$ operations. Details of
		   procedures that achieve these savings are described, and
		   the $O(n^{7/3})$ complexity is confirmed by numerical
		   results.},
 summary	= {In many trust-region algorithms, each iteration seeks a
		   vector $d \in \Re^n$ that solves the linear system of
		   equations $(B + \lambda I) d=- g$, where $B$ is a symmetric
		   estimate of a second derivative matrix, $g$ is a known
		   gradient vector, and $\lambda$ is a parameter that controls
		   the length of $d$. Several values of $\lambda$ may be tried
		   on each iteration, and, when there is no helpful sparsity
		   in $B$, it is usual for each solution to require $O(n^3)$
		   operations. However, if an orthogonal matrix $\Omega$ is
		   available such that $M=\Omega^T B \Omega$ is an $n \times
		   n$ matrix of bandwidth $2s+1$, then $\Omega^Td$ can be
		   calculated in only $O(ns^2)$ operations for each new
		   $\lambda$ by writing the system in the form $(M + \lambda
		   I)(\Omega^Td=- \Omega^Tg$. Unfortunately, it is found that
		   the construction of $M$ and $\Omega$ from $B$ is usually
		   more expensive than the solution of the original system,
		   but in variable metric and quasi-Newton algorithms for
		   unconstrained optimization, each iteration changes $B$ by a
		   matrix whose rank is at most two, and then updating
		   techniques can be applied to $\Omega$. Thus it is possible
		   to reduce the average work per iteration from $O(n^3)$ to
		   $O(n^{7/3})$ operations. Here the elements of each
		   orthogonal matrix are calculated explicitly, but instead
		   one can express the orthogonal matrix updates as products
		   of Givens rotations, which allows the average work per
		   iteration to be only $O(n^{11/5})$ operations. Details of
		   procedures that achieve these savings are described, and
		   the $O(n^{7/3})$ complexity is confirmed by numerical
		   results.}}

@article{Powe98b,
 author		= {M. J. D. Powell},
 title		= {Direct search algorithms for optimization calculations},
 journal	= {Acta Numerica},
 volume		= 7, pages = {287--336}, year = 1998}

@misc{Powe98c,
 author         = {M. J. D. Powell},
 title          = {A quadratic model trust region method for unconstrained
                   minimization without derivatives},
 howpublished	= {Presentation at the International Conference on Nonlinear
                   Programming and Variational Inequalities, Hong Kong},
 year           = 1998,
 abstract       = {A trust region method for unconstrained minimization
                   calculates a trial change in the variables by minimizing
                   an approximation to the objective function subject to a
                   bound on the length of the trial step.  The author has
                   developed an easy-to-use algorithm of this kind by letting
                   each approximation be a linear polynomial, but the rate of
                   convergence is usually very slow because second derivatives
                   are ignored.  Therefore we will consider the use of
                   quadratic approximations that are quadratic polynomials. 
                   They are constructed by interpolation to values of the
                   objective function, so one has to ensure that the positions
                   of the interpolation points are suitable. recent work on
                   this important question will be reviewed.  Attention will
                   be given to the adjustment of the trust region radius,
                   including the idea of having a separate radius for
                   controlling the distance between interpolation points.},
 summary        = {A derivative-free trust-region method for unconstrained 
                   optimization is described that uses quadratic
                   interpolation models.  These are chosen to be linear
                   combination of the Lagrange fundamental polynomials
                   associated with the interpolation problem. It is shown
                   that the coefficients of these polynomials can be updated
                   from iteration to iteration in a numerically stable way.
                   The method also uses a separate radius for controlling the
                   distance between interpolation points.}}

@article{PoweToin79,
 author		= {M. J. D. Powell and Ph. L. Toint},
 title		= {On The Estimation of Sparse {H}essian Matrices},
 journal	= SINUM,
 volume		= 16, number = 6, pages = {1060--1074}, year = 1979}

@article{PoweYuan86,
 author		= {M. J. D. Powell and Y. Yuan},
 title          = {A recursive quadratic-programming algorithm that uses
                   differentiable exact penalty-functions},
 journal        = MP,
 volume         = 35, number = 3, pages = {265--278}, year = 1986}

@article{PoweYuan90,
 author		= {M. J. D. Powell and Y. Yuan},
 title		= {A trust region algorithm for equality constrained
		   optimization},
 journal	= MP,
 volume		= 49, number = 2, pages = {189--213}, year = 1990,
 abstract	= {A trust region algorithm for equality constrained
		   optimization is proposed that employs a differentiable
		   exact penalty function. Under certain conditions global
		   convergence and local superlinear convergence results are
		   proved.},
 summary	= {A trust-region algorithm for equality constrained
		   optimization is proposed that employs a differentiable
		   exact penalty function. Under certain conditions global
		   convergence and local superlinear convergence results are
		   proved.}}

@misc{PrieMogu99,
 author         = {F. Prieto and J. M. Moguerza},
 title          = {Interior-Point Methods using Negative Curvature},
 howpublished   = {Presentation at the First Workshop on Nonlinear
                   Optimization ``Interior-Point and Filter Methods'',
                   Coimbra, Portugal},
 year           = 1999,
 abstract       = {Interior-point methods are very promising for the solution
                   of large-scale nonlinear problems.  In the nonconvex case,
                   the use of negative curvature information may allow
                   additional improvements in the behaviour of these methods
                   without any significant increase in their computational
                   costs.  However, the efficient implementation of such a
                   method requires addressing several issues; for example,
                   how to guarantee the convergence of the method, and how
                   to compute and use the negative-curvature information
                   without incussring in excessive costs.  We describe the
                   implementation of two variants of an interior-point method
                   using negative curvature.  Particular attention is paid to
                   the conditions under which the negative curvature
                   information is used, the way in which the descent and
                   negative curvature directions are combined, and to the
                   updating of the barrier parameter.  The convergence
                   properties of the method are analyzed, and the conditions
                   under which the methods are globally convergent and may
                   attain quadratic convergence are discussed.  Finally,
                   computational results on a set of small and medium-sized
                   problems are presented and compared with those obtained
                   using other interior-point implementations, and with the
                   results obtained by the proposed method when negative
                   curvature information is not used.},
 summary        = {The implementation of two variants of an interior-point
                   method using negative curvature is discussed.  Particular
                   attention is paid to the conditions under which the negative
                   curvature information is used, the way in which the descent
                   and negative curvature directions are combined, and to the
                   updating of the barrier parameter.  The conditions under
                   which the methods are globally convergent and may attain
                   quadratic convergence are discussed.  Computational results
                   on a set of small and medium-sized problems are compared 
                   with those obtained using other interior-point
                   implementations, and with those obtained by the proposed
                   method when negative curvature information is not used.}}

@article{PropPukh93,
 author		= {A. I. Propoi and A. V. Pukhlikov},
 title		= {{N}ewton Stochastic Method in nonlinear extremal problems},
 journal	= {Automation and Remote Control},
 volume		= 54, number = {4--Part 1}, pages = {605--613}, year = 1993, 
 abstract       = {This paper is concerned with the construction of
                   consistent model-trust region pairs for optimization
                   procedures of the Newtonian type. A problem of random
                   extremal search in the class of normal distributions
                   is studied. Two "training" and "improvement"
                   components of optimization motion are singled out and
                   analyzed.},
 summary        = {A random search procedure are explored in the context
		   of trust-region methods.}}

@article{Psch70,
 author		= {B. N. Pschenichny},
 title		= {Algorithms for general problems of mathematical programming},
 journal	= {Kibernetica},
 volume		= 6, pages = {120--125}, year = 1970}

@article{PsiaPark95,
 author		= {M. Psiaki and K. Park},
 title		= {Augmented {L}agrangian Nonlinear-Programming algorithm that
		   uses {SQP} and trust region techniques},
 journal	= JOTA,
 volume		= 86, number = 2, pages = {311--325}, year = 1995,
 abstract	= {An augmented Lagrangian nonlinear programming algorithm has
		   been developed. Its goals are to achieve robust global
		   convergence and fast local convergence. Several unique
		   strategies help the algorithm achieve these dual goals. The
		   algorithm consists of three nested loops. The outer loop
		   estimates the Kuhn-Tucker multipliers at a rapid linear
		   rate of convergence. The middle loop minimizes the
		   augmented Lagrangian function for fixed multipliers. This
		   loop uses the sequential quadratic programming technique
		   with a box trust region stepsize restriction. The inner
		   loop solves a single quadratic program. Slack variables and
		   a constrained form of the fixed-multiplier middle-loop
		   problem work together with curved line searches in the
		   inner-loop problem to allow large penalty weights for rapid
		   outer-loop convergence. The inner-loop quadratic programs
		   include quadratic constraint terms, which complicate the
		   inner loop, but speed the middle-loop progress when the
		   constraint curvature is large. The new algorithm compares
		   favorably with a commercial sequential quadratic
		   programming algorithm on five low-order test problems. Its
		   convergence is more robust, and its speed is not much
		   slower.},
 summary	= {An augmented Lagrangian nonlinear programming algorithm is
		   developed. The algorithm consists of three nested loops.
		   The outer loop estimates the Kuhn-Tucker multipliers at a
		   rapid linear rate of convergence. The middle loop minimizes
		   the augmented Lagrangian function for fixed multipliers.
		   This loop uses the sequential quadratic programming
		   technique with a box trust-region stepsize restriction. The
		   inner loop solves a single quadratic program. Slack
		   variables and a constrained form of the fixed-multiplier
		   middle-loop problem work together with curved linesearches
		   in the inner-loop problem to allow large penalty weights
		   for rapid outer-loop convergence. The inner-loop quadratic
		   programs include quadratic constraint terms, which
		   complicate the inner loop, but speed the middle-loop
		   progress when the constraint curvature is large.}}

%%% Q %%%

@article{QiSun94,
 author		= {L. Qi and J. Sun},
 title		= {A trust region algorithm for minimization of locally
		   {L}ipschitzian functions},
 journal	= MP,
 volume		= 66, number = 1, pages = {25--43}, year = 1994,
 abstract	= {The classical trust region algorithm for smooth nonlinear
		   programs is extended to the nonsmooth case where the
		   objective function is only locally Lipschitzian. At each
		   iteration, an objective function that carries both first
		   and second order information is minimized over a trust
		   region. The term that carries the first order information
		   is an iteration function that may not explicitly depend on
		   subgradients or directional derivatives. We prove that the
		   algorithm is globally convergent. This convergence result
		   extends the result of \citebb{Powe84} for minimization of
		   smooth functions, the result of \citebb{Yuan85b} for
		   minimization of composite convex functions, and the result
		   of \citebb{DennLiTapi95} for minimization of regular
		   functions. In addition, compared with the recent model of
		   \citebb{PangHanRang91} for minimization of locally
		   Lipschitzian functions using a linesearch, this algorithm
		   has the same convergence property without assuming positive
		   definiteness and uniform boundedness of the second order
		   term. Applications of the algorithm to various nonsmooth
		   optimization problems are discussed.},
 summary	= {The classical trust-region algorithm for smooth nonlinear
		   programs is extended to the non-smooth case where the
		   objective function is only locally Lipschitzian. At each
		   iteration, an objective function that uses both first and
		   second order information is minimized over a trust region.
		   The term that carries the first order information is an
		   iteration function that may not explicitly depend on
		   subgradients or directional derivatives. It is proved that
		   the algorithm is globally convergent. Applications of the
		   algorithm to various non-smooth optimization problems are
		   discussed.}}
 
@article{Qi95,
 author		= {L. Qi},
 title		= {Trust Region Algorithms for Solving Nonsmooth Equations},
 journal	= SIOPT,
 volume		= 5, number = 1, pages = {219--230}, year = 1995,
 abstract	= {Two globally convergent trust region algorithms are
		   presented for solving nonsmooth equations, where the
		   functions are only locally Lipschitzian. The first
		   algorithm is an extension of the classic
		   Levenberg-Marquardt method by approximating the locally
		   Lipschitzian function with a smooth function and using the
		   derivative of the smooth function in the algorithm wherever
		   a derivative is needed. Global convergence for this
		   algorithm is established under a regular condition. In the
		   second algorithm, successive smooth approximation functions
		   and their derivatives are used. Global convergence for the
		   second algorithm is established under mild assumptions.
		   Both objective functions of subproblems of these two
		   algorithms are quadratic functions.},
 summary	= {Two globally convergent trust-region algorithms are
		   presented for solving non-smooth equations, for the case
		   where the functions are only locally Lipschitzian. The
		   first algorithm is an extension of the classic
		   Levenberg-Morrison-Marquardt method, obtained by
		   approximating the locally Lipschitzian function with a
		   smooth function and using the derivative of the smooth
		   function in the algorithm wherever a derivative is needed.
		   Global convergence is established under a regularity
		   condition. In the second algorithm, successive smooth
		   approximation functions and their derivatives are used.
		   Global convergence for the second algorithm is established
		   under mild assumptions. Both objective functions of
		   subproblems of these two algorithms are quadratic
		   functions.}}

@techreport{QiQiSun99,
 author         = {H. Qi and L. Qi and D. Sun},
 title          = {Solving {KKT} Systems via the Trust Region and the 
                   Conjugate Gradient Methods},
 institution    = {School of Mathematics, The university of New South Wales},
 address        = {Sydney, Australia},
 number         = {15-09-99}, year = 1999,
 abstract       = {In this paper, we propose a trust region method for
                   solving KKT systems arising from the variational inequality
                   problem and the constrained optimization problem.  The
                   trust region subproblem is derived from the reformulation
                   of the KKT system as a constrained optimization problem and
                   is solved by the truncated conjugate gradient method;
                   meanwhile the variables remain feasible with respect to
                   the constrained optimization problem.  Global and
                   superlinear convergence are established.  Some preliminary
                   numerical experiments show that the method is quite 
                   promising.},
 summary        = {A trust-region method is proposed for solving KKT systems
                   arising from the variational inequality and the constrained
                   optimization problems.  The trust-region subproblem is
                   derived from the reformulation of the KKT system as a
                   constrained optimization problem and is solved by the 
                   truncated conjugate gradient method while maintaining
                   feasibility. Global and superlinear convergence is
                   established.  Preliminary numerical experiments illustrate
                   the method.}}

%%% R %%%

@inproceedings{Reid71,
 author		= {J. K. Reid},
 title		= {On the method of conjugate gradients for the solution of
		   large sparse linear equations},
 booktitle	= {Large sparse sets of linear equations},
 editor		= {J. K. Reid},
 publisher	= AP, address = AP-ADDRESS,
 pages		= {231--254}, year = 1971}

@inproceedings{Reid73,
 author		= {J. K. Reid},
 title		= {Least squares solution of sparse systems of non-linear
		   equations by a modified {M}arquardt algorithm},
 booktitle	= {Decomposition of Large-Scale Problems},
 editor		= {D. M. Himmelblau},
 publisher	= NH, address = NH-ADDRESS,
 pages		= {437--445}, year = 1973,
 abstract	= {Marquardt's algorithm is adapted to exploit sparsity in
		   non-linear least squares problem that may or may not be
		   overdetermined. Consideration is given to cases when
		   derivatives are available analytically and where they have
		   to be estimated. The results of numerical experiments are
		   presented.},
 summary	= {The Levenberg-Morrison-Marquardt algorithm is compared to
		   the dogleg method for sparse least-squares problems.
		   Approximation scheme for the Jacobian are also considered.}}

@article{Rein71,
 author		= {C. Reinsch},
 title		= {Smoothing by spline functions {II}},
 journal	= NUMMATH,
 volume		= 16, pages = {451--454}, year = 1971}

@article{RendWolk97,
 author		= {F. Rendl and H. Wolkowicz},
 title		= {A Semidefinite Framework for Trust Region Subproblems with
		   Applications to Large Scale Minimization},
 journal	= MP,
 volume		= 77, number = 2, pages = {273--299}, year = 1997,
 abstract	= {A primal-dual pair of semidefinite programs provides a
		   general framework for the theory and algorithms for the
		   trust region subproblem (TRS). This problem consists in
		   minimizing a general quadratic function subject to a convex
		   quadratic constraint and, therefore, it is a generalization
		   of the minimum eigenvalue problem. The importance of TRS is
		   due to the fact that it provides the step in trust region
		   minimization algorithms. The semidefinite framework is
		   studied as an interesting instance of semidefinite
		   programming as well as a tool for viewing known algorithms
		   and deriving new algorithms for TRS. In particular, a dual
		   simplex type method is studied that solves TRS as a
		   parametric eigenvalue problem. This method uses the Lanczos
		   algorithm for the smallest eigenvalue as a black box.
		   Therefore, the essential cost of the algorithm is the
		   matrix-vector multiplication and, thus, sparsity can be
		   exploited. A primal simplex type method provides steps for
		   the so-called hard case. Extensive numerical tests for
		   large sparse problems are discussed. These tests show that
		   the cost of the algorithm is $1+\alpha(n)$ times the cost
		   of finding a minimum eigenvalue using the Lanczos
		   algorithm, where $0<\alpha(n)<1$ is a fraction which
		   decreases as the dimension increases.},
 summary	= {A primal-dual pair of semidefinite programs provides a
		   general framework for the theory and algorithms for the
		   trust region subproblem (TRS). This problem is a
		   generalization of the minimum eigenvalue problem. The
		   semidefinite framework is studied as an instance of
		   semidefinite programming as well as a tool for viewing
		   known algorithms and deriving new algorithms for TRS. In
		   particular, a dual simplex type method is studied that
		   solves TRS as a parametric eigenvalue problem. This method
		   uses the Lanczos algorithm for the smallest eigenvalue as a
		   black box. Therefore, the essential cost of the algorithm
		   is the matrix-vector multiplication and, thus, sparsity can
		   be exploited. A primal simplex type method provides steps
		   for the so-called hard case. Numerical tests for large
		   sparse problems show that the cost of the algorithm is
		   $1+\alpha(n)$ times the cost of finding a minimum
		   eigenvalue using the Lanczos algorithm, where
		   $0<\alpha(n)<1$ is a fraction which decreases as the
		   dimension increases.}}

@article{RendVandWolk95,
 author		= {F. Rendl and R. J. Vanderbei and H. Wolkowicz},
 title		= {Max-min eigenvalue problems, primal-dual interior point
		   algorithms, and trust region subproblems},
 journal	= OMS,
 volume		= 5, number = 1, pages = {1--16}, year = 1995,
 abstract	= {Two Primal-dual interior point algorithms are presented for
		   the problem of maximizing the smallest eigenvalue of a
		   symmetric matrix over diagonal perturbations. These
		   algorithms prove to be simple, robust, and efficient. Both
		   algorithms are based on transforming the problem to one
		   with constraints over the cone of positive semidefinite
		   matrices, i.e. L\"{o}wner order constraints. One of the
		   algorithms does this transformation through an intermediate
		   transformation to a trust region subproblem. This allows
		   the removal of a dense row.},
 summary	= {Two primal-dual interior-point algorithms are presented for
		   maximizing the smallest eigenvalue of a symmetric matrix
		   over diagonal perturbations. These algorithms prove to be
		   simple, robust, and efficient. Both algorithms are based on
		   transforming the problem to one with constraints over the
		   cone of positive semidefinite matrices. One of the
		   algorithms does this transformation through an intermediate
		   transformation to a trust-region subproblem. This allows
		   the removal of a dense row.}}

@article{Robi74,
 author		= {S. M. Robinson},
 title		= {Perturbed {K}uhn-{T}ucker points and rates of convergence
		   for a class of nonlinear programming algorithms},
 journal	= MP,
 volume		= 7, number = 1, pages = {1--16}, year = 1974}

@inproceedings{Robi83,
 author		= {S. M. Robinson},
 title		= {Generalized equations},
 crossref	= {BachGrotKort83}, pages = {346--367}}

@book{Rock70,
 author		= {R. T. Rockafellar},
 title		= {Convex Analysis},
 publisher	= {Princeton University Press}, address = {Princeton, USA},
 year		= 1970}

@article{Rock74,
 author		= {R. T. Rockafellar},
 title		= {Augmented {L}agrangian multiplier functions and duality in
		   nonconvex programming},
 journal	= SICON,
 volume		= 12, number = 2, pages = {268--285}, year = 1974}

@article{Rock76,
 author		= {R. T. Rockafellar},
 title		= {Augmented {L}agrangians and applications of the proximal
		   point algorithm in convex programming},
 journal	= MOR,
 volume		= 1, pages = {97--116}, year = 1976}

@article{Rock76b,
 author		= {R. T. Rockafellar},
 title		= {Monotone Operators and the Proximal Point Algorithm},
 journal	= SICON,
 volume		= 14, pages = {877--898}, year = 1976}

@inproceedings{Rock83,
 author		= {R. T. Rockafellar},
 title		= {Generalized subgradients in mathematical programming},
 crossref	= {BachGrotKort83}, pages = {368--390}}

@article{RodrRenaWats99,
 author		= {J. F. Rodr\`{\i}guez and J. E. Renaud and L. T. Watson},
 title		= {Convergence of Trust Region Augmented {L}agrangian Methods
		   Using Variable Fidelity Approximation Data},
 journal	= {Structural Optimization},
 volume         = 15, number = {3--4}, pages = {141--156}, year = 1999,
 abstract	= {To date the primary focus of most constrained approximate
		   optimization strategies is that application of the method
		   should lead to improved designs. Few researchers have
		   focused on the development of constrained approximate
		   optimization strategies that are assured of converging to a
		   Karush-Kuhn-Tucker (KKT) point for the problem. Recent work
		   by the authors based on a trust region model management
		   strategy has shown promise in managing the convergence of
		   constrained approximate optimization in application to a
		   suite of single level optimization test problems. Using a
		   trust-region model management strategy, coupled with an
		   augmented Lagrangian approach for constrained approximate
		   optimization, the authors have shown in application studies
		   that the approximate optimization process converges to a
		   KKT point for the problem. The approximate optimization
		   strategy sequentially builds a cumulative response surface
		   approximation of the augmented Lagrangian which is then
		   optimized subject to a trust region constraint. In this
		   research the authors develop a formal proof of convergence
		   for the response surface approximation based optimization
		   algorithm. Previous application studies were conducted on
		   single level optimization problems for which response
		   surface approximations were developed using conventional
		   statistical response sampling techniques such as central
		   composite design to query a high fidelity model over the
		   design space. In this research the authors extend the scope
		   of application studies to include the class of
		   multidisciplinary design optimization (MDO) test problems.
		   More importantly the authors show that response surface
		   approximations constructed from variable fidelity data
		   generated during concurrent subspace optimizations (CSSOs)
		   can be effectively managed by the trust region model
		   management strategy.},
 summary	= {An augmented Lagrangian trust-region method is given, that
		   converges to a Karush-Kuhn-Tucker point for constrained
		   optimization. The method behaves well on single level
		   optimization test problems. Applications include
		   multidisciplinary design optimization test problems. It is
		   shown that response surface approximations constructed from
		   variable fidelity data generated during concurrent subspace
		   optimizations can be effectively managed by the
		   trust-region model management strategy.}}

@article{RodrRenaWats98b,
 author		= {J. F. Rodr\`{\i}guez and J. E. Renaud and L. T. Watson},
 title		= {Trust-region augmented {L}agrangian methods for sequential
		   response surface approximation and optimization},
 journal	= {Journal of Mechanical Design},
 volume		= 120, number = 1, pages = {58--66}, year = 1998,
 abstract	= {A common engineering practice is the use of approximation
		   models in place of expensive computer simulations to drive
		   a multidisciplinary design process based on nonlinear
		   programming techniques. The use of approximation strategies
		   is designed to reduce the number of detailed, costly
		   computer simulations required during optimization while
		   maintaining the pertinent features of the design problem.
		   To date the primary focus of most approximate optimization
		   strategies is that application of the method should lead to
		   improved designs. This is a laudable attribute and
		   certainly relevant for practicing designers. However to
		   date few researchers have focused on the development of
		   approximate optimization strategies that are assured of
		   converging to a solution of the original problem. Recent
		   works based on trust region model management strategies
		   have shown promise in managing convergence in unconstrained
		   approximate minimization. In this research we extend these
		   well established notions from the literature on
		   trust-region methods to manage the convergence of the more
		   general approximate optimization problem where equality,
		   inequality and variable bound constraints are present. The
		   primary concern addressed in this study is how to manage
		   the interaction between the optimization and the fidelity
		   of the approximation models to ensure that the process
		   converges to a solution of the original constrained design
		   problem. Using a trust-region model management strategy
		   coupled with an augmented Lagrangian approach for
		   constrained approximate optimization, one can show that the
		   optimization process converges to a solution of the
		   original problem. In this research an approximate
		   optimization strategy is developed in which a cumulative
		   response surface approximation of the augmented Lagrangian
		   is sequentially optimized subject to a trust region
		   constraint. Results for several test problems are presented
		   in which convergence to a Karush-Kuhn-Tucker (KKT) point is
		   observed.},
 summary	= {A common engineering practice is the use of approximation
		   models in place of expensive computer simulations to drive
		   a multidisciplinary design process based on nonlinear
		   programming techniques. Well established notions on
		   trust-region methods are extended to manage the convergence
		   of the general approximate problem where equality,
		   inequality and variable bound constraints are present. The
		   primary concern is to manage the interaction between the
		   optimization and the fidelity of the approximation models
		   to ensure that the process converges to a solution of the
		   original constrained design problem. This is achieved by
		   using a trust-region model management strategy coupled with
		   an augmented Lagrangian approach for constrained
		   approximate optimization. An approximate optimization
		   strategy is developed in which a cumulative response
		   surface approximation of the augmented Lagrangian is
		   sequentially optimized subject to a trust region
		   constraint. Results for several test problems are presented
		   in which convergence to a Karush-Kuhn-Tucker (KKT) point is
		   observed.}}

@inproceedings{RogeTerpGoss88,
 author         = {A. Roger and P. Terpolilli and O. Gosselin},
 title          = {Trust region methods for seismic inverse problems},
 booktitle      = {Proceedings of the XVIth Workshop on Interdisciplinary 
                   Study of Inverse Problems: Some Topics on Inverse Problems},
 editor         = {P. C. Sabatier},
 publisher      = {World Scientific}, address = {Singapore},
 pages          = {93--103}, year = 1988,
 abstract       = {The authors present a class of optimization
                   algorithms, called trust region algorithms which
                   exhibit attractive theoretical convergence
                   properties. They outline the main features of trust
                   region algorithms, give a few classical properties
                   without demonstration, and present numerical results
                   which show that this class of algorithm actually fits
                   the required features.},
 summary        = {Trust-region methods are presented in the context of
		   seismic inversion problems.}}

@phdthesis{Roja98,
 author         = {M. Rojas},
 title          = {A large-scale trust-region approach to the regularization 
		   of discrete ill-posed problems},
 school         = {Rice University}, address = RICE-ADDRESS,
 year		= 1998,
 abstract	= {We consider the problem of computing the solution of
		   large-scale discrete ill-posed problems when there is noise
		   in the data. These problems arise in important areas such
		   as seismic inversion, medical imaging and signal
		   processing.  We pose the problem as a quadratically 
		   constrained least squares problem and develop a method for
		   the solution of such problem.  Our method does not require
		   factorization of the coefficient matrix, it has very low
		   storage requirements and handles the high degree of 
		   singularities arising in discrete ill-posed problems.  We
		   present numerical results on test problems and an
		   application of the method to a practical problem with real
		   data.}, 
 summary	= {A algorithm based on the proposals by \citebb{Sore97} and
		   \citebb{SantSore95} is described for the solution of
		   large-scale linear least-squares problems subject to a
		   quadratic constraint. It is applied to regularize
		   large discrete ill-posed problems. Numerical experiments 
		   on test cases and a real inverse interpolation problem
		   illustrate the method.}}

@techreport{RojaSantSore99,
 author		= {M. Rojas and S. A. Santos and D. C. Sorensen},
 title		= {A new matrix-free algorithm for the large-scale
		   trust-region subproblem},
 institution	= CAAM, address = RICE-ADDRESS,
 number		= {TR99-19}, year = 1999,
 abstract	= {We present a matrix-free algorithm for the large-scale 
                   trust-region subproblem.  Our algorithm relies on
                   matrix-vector products only and does not require
                   matrix factorizations. We recast the trust-region
                   subproblem as a parametrized eigenvalue problem and
                   compute an optimal value for the parameter. We then
                   find the optimal solution of the trust-region
                   subproblem from the eigenvectors associated with two
                   of the smallest eigenvalues of the parameterized
                   eigenvalue problem corresponding to the optimal
                   parameter. The new algorithm uses a different
                   interpolating scheme than existent methods and
                   introduces a unified iteration that naturally
                   includes the so-called hard case. We show that the
                   new iteration is well defined and convergent at a
                   superlinear rate. We present computational results to
                   illustrate convergence properties and robustness of
                   the method.},
 summary        = {A matrix-free algorithm for the large-scale 
                   trust-region subproblem is presented, that relies on
                   matrix-vector products only and does not require
                   matrix factorizations. the trust-region subproblem
                   is recast as a parametrized eigenvalue problem and
                   an optimal value for the parameter computed. 
                   The optimal solution of the trust-region subproblem
                   is then found from the eigenvectors associated with two
                   of the smallest eigenvalues of the parameterized
                   eigenvalue problem corresponding to the optimal
                   parameter. The new algorithm uses a unified iteration
                   that naturally includes the hard case, and is superlinearly
                   convergent. Computational results illustrate convergence
                   properties and robustness of the method.}}

@article{Rose60,
 author		= {H. H. Rosenbrock},
 title		= {An automatic method for finding the greatest or least value
		   of a function},
 journal	= COMPJ,
 volume		= 3, pages = {175--184}, year = 1960}

@article{RoyServ99,
 author		= {R. Roy and Sevick Muraca, E. M.},
 title		= {Truncated {N}ewton's optimization scheme for absorption 
                   and fluorescence optical tomography: {P}art {I} 
                   theory and formulation },
 journal	= {Optics Express},
 volume		= 4, number = 10, pages = {353--371}, year = 1999,
 abstract	= {The development of non-invasive, biomedical optical 
                   imaging from time-dependent measurements of
                   near-infrared (NIR) light propagation in tissues
                   depends upon two crucial advances: (i) the
                   instrumental tools to enable photon
                   ''time-of-flight'' measurement within rapid and
                   clinically realistic times, and (ii) the
                   computational tools enabling the reconstruction of
                   interior tissue optical property maps from exterior
                   measurements of photon ''time-of-flight'' or photon
                   migration. In this contribution, the image
                   reconstruction algorithm is formulated as an
                   optimization problem in which an interior map of
                   tissue optical properties of absorption and
                   fluorescence lifetime is reconstructed from
                   synthetically generated exterior measurements of
                   frequency-domain photon migration (FDPM). The inverse
                   solution is accomplished using a truncated Newton's
                   method with trust region to match synthetic
                   fluorescence FDPM measurements with that predicted by
                   the finite element prediction. The computational
                   overhead and error associated with computing the
                   gradient numerically is minimized upon using modified
                   techniques of reverse automatic differentiation.},
 summary	= {The development of non-invasive, biomedical optical 
                   imaging from time-dependent measurements of
                   near-infrared (NIR) light propagation in tissues
                   depends upon two crucial advances: (i) the
                   instrumental tools to enable photon
                   ''time-of-flight'' measurement within rapid and
                   clinically realistic times, and (ii) the
                   computational tools enabling the reconstruction of
                   interior tissue optical property maps from exterior
                   measurements of photon ''time-of-flight'' or photon
                   migration. The image reconstruction algorithm is
                   formulated as an optimization problem in which an
                   interior map of tissue optical properties of
                   absorption and fluorescence lifetime is reconstructed
                   from synthetically generated exterior measurements of
                   frequency-domain photon migration (FDPM). The inverse
                   solution is accomplished using a truncated Newton's
                   method with trust region to match synthetic
                   fluorescence FDPM measurements with that predicted by
                   the finite element prediction. The computational
                   overhead and error associated with computing the
                   gradient numerically is minimized upon using modified
                   techniques of reverse automatic differentiation.}}

@article{Rudn94,
 author         = {M. Rudnicki},
 title          = {Smoothing strategies in solving inverse electromagnetic 
                   problems},
 journal        = {International Journal of Applied Electromagnetics in 
                   Materials},
 volume         = 4, number = 3, pages = {239-264}, year = 1994,
 abstract       = {Many inverse and optimal design problems of
                   electrical engineering are formulated in terms of
                   least squares methodology (linear and nonlinear least
                   squares). The objective function used makes a
                   square-root deviation between prescribed and actual
                   field distribution in a controlled subregion. In the
                   paper some numerical methods that proved to be
                   particularly useful in solving such problems of
                   electrical engineering are presented. The common
                   feature of these methods is the need of choosing a
                   smoothing parameter controlling the solution
                   quality. It is shown how this parameter may be chosen
                   when using the linear least squares (regularization)
                   approach and the trust-region approach in the
                   nonlinear least squares method. For completeness the
                   author presents the zeroth-order stochastic methods
                   of optimization as well. As opposed to the least
                   squares approach, the latter do not require
                   restrictive a priori assumptions about convexity and
                   smoothness. Some electromagnetic optimal design
                   problems solved by means of the above techniques are
                   referred.},
 summary        = {It is shown how the regularization parameter may
		   be chosen when using the linear least-squares 
		   approach and the trust-region approach
		   in the nonlinear least squares method for solving inverse
		   and optimal design problems of electrical engineering. The
		   zeroth-order stochastic methods of optimization is also
		   discussed, because it does not require 
                   restrictive a priori assumptions about convexity and
                   smoothness. Some electromagnetic optimal design
                   problems solved by means of these techniques.}}

%%% S %%%

@book{Saad91,
 author		= {Y. Saad},
 title		= {Numerical Methods for Large Eigenvalue Problems},
 publisher	= {Manchester University Press},
 year		= 1991}

@book{Saad96,
 author		= {Y. Saad},
 title		= {Iterative Methods for Sparse Linear Systems},
 publisher	= {PWS Publishing Company}, address = {Boston, USA},
 year		= 1996}

@techreport{SachSart99,
 author		= {E. W. Sachs and A. Sartenaer},
 title		= {A Class of Augmented {L}agrangian Algorithms for Infinite
		   Dimensional Optimization with Equality Constraints},
 institution	= FUNDP, address = FUNDP-ADDRESS,
 number		= {(in preparation)}, year = 1999}

@article{SadjPonn99, 
 author         = {S. J. Sadjadi and K. Ponnambalam},
 title          = {Advances in trust region algorithms for constrained 
                   optimization},
 journal        = {Applied Numerical Mathematics},
 volume         = 29, number = 3, pages = {423--443}, year = 1999,
 abstract       = {Constrained optimization problems occur in many applications 
                   of engineering, science and medicine. Much attention
                   has recently been devoted to solving this class of
                   problems using trust region algorithms with strong
                   convergence properties, in part because of the
                   availability of reliable software. This paper
                   presents a survey of recent advances in trust region
                   algorithms. We then explain the different choices of
                   penalty function, Lagrange function and expanded
                   Lagrangian function used for modeling constrained
                   optimization problems and solving these equations
                   using trust region algorithms. Finally, some
                   numerical results for the implementation of our
                   proposed method on different test problems with
                   various sizes are presented.},
 summary        = {A survey of recent advances in trust-region methods
                   for constrained minimization is given.  Different
                   choices for the penalty function, Lagrange function
                   and expanded Lagrangian functions which are used are
                   compared.  Some numerical results for an
                   implementation of a recommended method on different
                   test problems with various sizes are presented.}}

@article{Sahb87,
 author		= {M. Sahba},
 title		= {Globally convergent algorithm for nonlinearly constrained
		   optimization problems},
 journal	= JOTA,
 volume		= 52, number = 2, pages = {291--309}, year = 1987}

@misc{SachSchuFrom98,
 author		= {E. W. Sachs and M. Schulze and S. Fromme},
 title		= {Neural Networks---An application of numerical optimization
		   in the financial markets},
 howpublished	= {Presentation at the Optimization 98 Conference, Coimbra},
 year		= 1998,
 abstract	= {We present results from a joint research project between a
		   research group of a bank and an optimization group of a
		   university. The goal was to develop an efficient code to
		   train neural networks and to use this software too to
		   forecast some economic indicators. We show how fully
		   interactive methods exploit the structure of the neural
		   networks and give theoretical and numerical results. The
		   software is applied to forecasting the German stock index
		   DAX using various input parameters. The success of the
		   forecast is measured in the development of the value of a
		   portfolio.},
 summary	= {The development of an efficient code to train neural
		   networks and the use of this software to forecast some
		   economic indicators is discussed. The proposed method
		   exploits the underdetermined nature of the application and
		   uses a Steihaug-Toint truncated conjugate gradient
		   trust-region method. The software is applied to forecasting
		   the German stock DAX index. The success of the forecast is
		   measured in the development of the value of a portfolio.}}

@article{SagaFuku91,
 author		= {N. Sagara and M. Fukushima},
 title		= {A Hybrid Method for the nonlinear least-squares problem
		   with simple bounds},
 journal	= JCAM,
 volume		= 36, number = 2, pages = {149--157}, year = 1991,
 abstract	= {This paper presents a new method with trust region
		   technique for solving the nonlinear least-squares problem
		   with lower and upper bounds on the variables. The proposed
		   method constructs trust region constraints that are
		   ellipses centered at the iterative points in such a way
		   that they lie in the interior of the feasible region. Thus
		   the method belongs to the class of interior point methods,
		   and hence we may expect that the generated sequence
		   approaches a solution smoothly without the combinatorial
		   complications inherent to traditional active set methods.
		   We establish a convergence theorem for the proposed method
		   and show its practical efficiency by numerical experiments.},
 summary	= {An interior trust-region method is presented for solving
		   the nonlinear least-squares problem with lower and upper
		   bounds on the variables. Convergence is established and the
		   practical efficiency of the method is illustrated by
		   numerical experiments.}}

@article{SagaFuku95,
 author		= {N. Sagara and M. Fukushima},
 title		= {A Hybrid Method for solving the nonlinear least-squares
		   problem with linear inequality constraints},
 journal	= {Journal of the Operations Research Society of Japan},
 volume		= 38, number = 1, pages = {55--69}, year = 1995,
 abstract	= {This paper presents a new method with trust region
		   technique for solving the nonlinear least squares problem
		   with linear inequality constraints. The method proposed in
		   this paper stems from the one presented in a recent paper
		   by the authors. The method successively constructs trust
		   region constraints, which are ellipsoids centered at the
		   iterative points, in such a way that they lie in the
		   relative interior of the feasible region. Thus the method
		   belongs to the class of interior point methods, and hence
		   we may expect that the generated sequences approaches a
		   solution smoothly without the combinatorial complications
		   inherent to traditional active set methods. We establish a
		   convergence theorem for the proposed method and show its
		   practical efficiency by numerical experiments.},
 summary	= {A trust-region method is presented for solving the
		   nonlinear least-squares problem with linear inequality
		   constraints. It is an adaptation of the method by
		   \citebb{SagaFuku91} to this more general case, and enjoy
		   similar properties.}}

@article{Sala87,
 author         = {D. E. Salane},
 title          = {A continuation approach for solving large-residual 
                   nonlinear least squares problems},
 journal        = SISSC,
 volume         = 8, number = 4, pages = {655--671}, year = {1987},
 abstract       = {This paper is concerned with the solution of the
                   nonlinear least squares problem. A continuation
                   method is used to develop a new framework for the
                   model trust region approach for solving nonlinear
                   least squares problem. This framework gives a
                   motivation for the direct selection of the trust
                   region parameter. It also provides a natural
                   safeguard for trust region methods and leads to a
                   very robust algorithm. A class of algorithms based on
                   the continuation method is presented. In addition,
                   the implementation details for one member of the new
                   class are examined. The convergence and descent
                   properties of this algorithm are also
                   discussed. Numerical evidence is given showing that
                   the new algorithms are competitive with existing
                   model trust region algorithms. For large-residual
                   problems or problems in which a good initial starting
                   guess is not available, the performance of the new
                   algorithm is very promising.},
 summary        = {A continuation method is used to develop a new framework
		   for the model trust-region approach for solving nonlinear
                   least squares problem,  which motivates
                   the direct selection of the trust-region parameter. It
		   also provides a safeguard for trust-region methods
		   and leads to a very robust algorithm. A class of algorithms
		   based on the continuation method is presented. In addition,
                   the implementation details for one member of the new
                   class are examined. Convergence and descent
                   properties of this algorithm are also
                   discussed. Numerical evidence is given showing that
                   the new algorithms are competitive with existing
                   trust-region algorithms. }}

@article{Salz60,
 author		= {H. E. Salzer},
 title		= {A note on the solution of quartic equations},
 journal	= MC,
 volume		= 14, number = 71, pages = {279--281}, year = 1960}

@techreport{SantSore95,
 author		= {S. A. Santos and D. C. Sorensen},
 title		= {A new matrix-free algorithm for the large-scale
		   trust-region subproblem},
 institution	= CAAM, address = RICE-ADDRESS,
 number		= {TR95-20}, year = 1995,
 abstract	= {The trust-region subproblem arises frequently in linear
		   algebra and optimization applications. Recently,
		   matrix-free methods have been introduced to solve
		   large-scale trust-region subproblems. These methods only
		   require a matrix-vector product and do not rely on matrix
		   factorizations (\bciteb{RendWolk97}, \bciteb{Sore97}).
		   These approaches recast the trust-region subproblem in
		   terms of a parameterized eigenvalue problem and then adjust
		   the parameter to find the optimal solution from the
		   eigenvector corresponding to the smallest eigenvalue of the
		   parameterized eigenvalue problem. This paper presents a new
		   matrix-free algorithm for the large-scale trust-region
		   subproblem. The new algorithm improves upon the previous
		   algorithms by introducing a unified iteration that
		   naturally includes the so called hard case. The new
		   iteration is shown to be superlinearly convergent in all
		   cases. Computational results are presented to illustrate
		   convergence properties and robustness of the method.},
 summary	= {A matrix-free algorithm for the large-scale trust-region
		   subproblem is presented, which improves upon the previous
		   algorithms by introducing a unified iteration that
		   naturally includes the hard case. The iteration is
		   superlinearly convergent in all cases. Computational
		   results are presented to illustrate its convergence
		   properties and robustness.}}

@inproceedings{Sarg74,
 author		= {R. W. H. Sargent},
 title		= {Reduced-gradient and projection methods for nonlinear
		   programming},
 crossref	= {GillMurr74a}, pages = {149--174}}

@misc{SargZhan98,
 author		= {R. W. H. Sargent and X. Zhang},
 title		= {An Interior-point Algorithm for Solving General Variational
		   Inequalities and Nonlinear Programs},
 howpublished	= {Presentation at the Optimization 98 Conference, Coimbra},
 year		= 1998}
% abstract	= {The paper describes a new algorithm for finding local
%		   solutions of general variational inequalities or
%		   nonlinear programs.  It applies the interior-point
%		   approach directly to the necessary conditions for the
%		   nonlinear problem, which can then be degenerate.  It
%	 	   is proved that the algorithm always has finite
%		   termination, and that the rate of convergence is
%		   globally linear, and under a certain regularity condition
%		   ultimately Q-subquadratic.  The regularity condition
%		   does not necessarily imply an isolated solution point.
%		   Numerical results are given for a selection of nonlinear
%		   programming problems from the CUTE package.}, 
% abstract	= {An algorithm for finding local solutions of general
%		   variational inequalities or nonlinear programs is described.
%		   It applies the interior-point approach directly to the
%		   necessary conditions for the nonlinear problem, which can
%		   then be degenerate.  It is proved that the algorithm always
%		   has finite termination, and that the rate of convergence
%		   is globally linear, and under a certain regularity
%		   condition ultimately Q-subquadratic.  The regularity
%		   condition does not necessarily imply an isolated solution
%		   point.  Numerical results are given for a selection of
%		   nonlinear programming problems from the {\sf CUTE} package.}}

@phdthesis{Sart91,
 author		= {A. Sartenaer},
 title		= {On some strategies for handling constraints in nonlinear
		   optimization},
 school		= FUNDP, address = FUNDP-ADDRESS,
 year		= 1991}

@article{Sart93b,
 author		= {A. Sartenaer},
 title		= {Armijo-type condition for the determination of a
		   generalized {C}auchy point in trust region algorithms using
		   exact or inexact projections on convex constraints},
 journal	= {Belgian Journal of Operations Research, Statistics and
		   Computer Science},
 volume		= 33, number = 4, pages = {61--75}, year = 1993,
 abstract	= {This paper considers some aspects of two classes of trust
		   region methods for solving constrained optimization
		   problems. The first class proposed by \citebb{Toin88} uses
		   techniques based on the explicitly calculated projected
		   gradient, while the second class proposed by
		   \citebb{ConnGoulSartToin96a} allows for inexact projections
		   on the constraints. We propose and analyze for each class a
		   step-size rule in the spirit of the Armijo rule for the
		   determination of a Generalized Cauchy Point. We then prove
		   under mild assumptions that, in both cases, the classes
		   preserve their theoretical properties of global convergence
		   and identification of the correct active set in a finite
		   number of iterations. Numerical issues are also discussed
		   for both classes.},
 summary	= {An Armijo step-size rule is proposed for the determination
		   of a Generalized Cauchy Point and analyzed for the
		   trust-region methods proposed by \citebb{Toin88} and
		   \citebb{ConnGoulSartToin96a}. It is proved under mild
		   assumptions that both classes preserve their theoretical
		   properties of global convergence and identification of the
		   correct active set in a finite number of iterations.
		   Numerical issues are also discussed for both classes.}}

@article{Sart95,
 author		= {A. Sartenaer},
 title		= {A class of trust region methods for nonlinear network
		   optimization problems},
 journal	= SIOPT,
 volume		= 5, number = 2, pages = {379--407}, year = 1995,
 abstract	= {We describe the results of a series of tests upon a class
		   of new methods of trust region type for solving the
		   nonlinear network optimization problem. The trust region
		   technique considered is characterized by the use of the
		   infinity norm and of inexact projections on the network
		   constraints. The results are encouraging and show that this
		   approach is particularly useful in solving large-scale
		   nonlinear network optimization problems, especially when
		   many bound constraints are expected to be active at the
		   solution.},
 summary	= {The results of a series of tests upon a class of
		   methods of trust-region type for solving the nonlinear
		   network optimization problem are described. The
		   trust-region technique considered is characterized by the
		   use of the infinity norm and of inexact projections on the
		   network constraints. The results are encouraging and show
		   that this approach is particularly useful in solving
		   large-scale nonlinear network optimization problems,
		   especially when many bound constraints are expected to be
		   active at the solution.}}

@article{Sart97,
 author		= {A. Sartenaer},
 title		= {Automatic determination of an initial trust region in
		   nonlinear programming},
 journal	= SISC,
 volume		= 18, number = 6, pages = {1788--1803}, year = 1997,
 abstract	= {This paper presents a simple but efficient way to find a
		   good initial trust region radius in trust region methods
		   for nonlinear optimization. The method consists of
		   monitoring the agreement between the model and the
		   objective function along the steepest descent direction,
		   computed at the starting point. Further improvements for
		   the starting point are also derived from the information
		   gleaned during the initializing phase. Numerical results
		   on a large set of problems show the impact the initial
		   trust region radius may have on trust region methods
		   behaviour and the usefulness of the proposed strategy.},
 summary	= {A simple but efficient way to find a good initial trust
		   region radius in trust-region methods for nonlinear
		   optimization consists of monitoring the agreement between
		   the model and the objective function along the 
		   steepest-descent direction at the starting point. Further
		   improvements for the starting point are also derived from
		   the information gleaned during the initializing phase.
		   Numerical results on a large set of problems show the
		   impact the initial trust region radius may have on
		   trust-region methods behaviour.}}

@article{Saue95,
 author		= {Th. Sauer},
 title		= {Computational aspects of multivariate polynomial
		   interpolation},
 journal	= {Advances in Computational Mathematics},
 volume		= 3, pages = {219--238}, year = 1995}

@misc{Saue96,
 author		= {Th. Sauer},
 title		= {Notes on polynomial interpolation},
 howpublished	= {Private communication},
 month		= {February}, year = 1996}


@article{SaueXu95,
 author		= {Th. Sauer and Y. Xu},
 title		= {On multivariate {L}agrange interpolation},
 journal	= MC,
 volume		= 64, pages = {1147--1170}, year = 1995}

@inproceedings{SchaLude94,
 author         = {J. Schaepperle and E. Luder},
 title          = {Optimization of distributed parameter systems with a 
                   combined statistical-deterministic method},
 booktitle      = {1994 IEEE International Symposium on Circuits and Systems},
 publisher      = {IEEE}, address = {New York, NY, USA}, 
 volume         = 6, pages = {141--144}, year = 1994,
 abstract       = {This paper describes an optimization method for
                   nonlinear systems with properties that depend on
                   functions instead of discrete parameters. The method
                   is applied to the design of systems with spatially
                   distributed parameters. The underlying mathematical
                   problem of the calculus of variations is approximated
                   by a finite dimensional constrained nonlinear
                   minimax-problem. This is solved with a method that
                   combines a deterministic algorithm for local
                   optimisation with a statistical method for global
                   optimization. The former is based on linearization
                   and linear programming with adaptive trust region,
                   while the latter uses elements from genetic methods
                   and pattern recognition. An example with a
                   nonlinearly loaded nonuniform transmission line shows
                   the capability of the algorithm to determine the
                   unknown optimum function with high precision.},
 summary        = {An optimization method is described for
                   nonlinear systems with properties that depend on
                   functions instead of discrete parameters. The method
                   is applied to the design of systems with spatially
                   distributed parameters. The underlying mathematical
                   problem of the calculus of variations is approximated
                   by a finite-dimensional constrained nonlinear
                   minimax-problem. This is solved with a method that
                   combines a deterministic algorithm for local
                   optimization with a statistical method for global
                   optimization. The former is based on linearization
                   and linear programming with adaptive trust region,
                   while the latter uses elements from genetic methods
                   and pattern recognition. An example with a
                   nonlinearly loaded non-uniform transmission line shows
                   the capability of the algorithm to determine the
                   unknown optimum function with high precision.}}

@article{Shii99,
 author		= {T. Shiina},
 title		= {Numerical solution technique for joint chance-constrained 
                   programming problem---an application to electric power 
                   capacity expansion },
 journal	= {Journal of the Operations Research Society of Japan},
 volume		= 42, number = 2, pages = {128--140}, year = 1999,
 abstract	= {We consider a joint chance-constrained linear programming 
                   problem with random right hand side vector. The
                   deterministic equivalent of the joint
                   chance-constraint is already known in the case that
                   the right hand side vector is statistically
                   independent. But if the right hand side vector is
                   correlative, it is difficult to derive the
                   deterministic equivalent of the joint
                   chance-constraint. We discuss two methods for
                   calculating the joint chance-constraint. For the case
                   of uncorrelated right hand side, we try a direct
                   method different from the usual deterministic
                   equivalent, for the correlative right hand side case,
                   we apply numerical integration. In this paper a
                   chance-constrained programming problem is developed
                   for electric power capacity expansion, where the
                   error of forecasted electricity demand is defined by
                   a random variable. Finally we show that this problem
                   can be solved numerically using the trust region
                   method and numerical integration, and we present the
                   results of our computational experiments.},
 summary	= {A joint chance-constrained linear programming 
                   problem with random right hand side vector is
                   considered.  The deterministic equivalent of the
                   joint chance-constraint is already known in the case
                   that the right hand side vector is statistically
                   independent. But if the right hand side vector is
                   correlated, it is difficult to derive the
                   deterministic equivalent of the joint
                   chance-constraint. Two methods for calculating the
                   joint chance-constraint are discussed.  For the case
                   of uncorrelated right hand side, a direct method
                   different from the usual deterministic equivalent is
                   tried, while for the correlated right hand side
                   case, numerical integration is applied. A
                   chance-constrained programming problem is developed
                   for electric power capacity expansion, where the
                   error of forecasted electricity demand is defined by
                   a random variable. This problem is solved numerically
                   using a trust region method, and numerical
                   integration, and results of computational experiments
                   are presented.}}

@article{Schi81,
 author		= {K. Schittkowski},
 title		= {The nonlinear programming method of {W}ilson, {H}an and
		   {P}owell with an augmented {L}agrangian type line search
		   function},
 journal	= NUMMATH,
 volume		= 38, pages = {83--114}, year = 1981}

@phdthesis{Schl95,
 author		= {S. Schleiff},
 title		= {Parametersch\"{a}tzung in nichtlinearen {M}odellen unter
		   besonderer {B}er\-\"{u}cks\-ichtigung kritischer {P}unkte},
 school		= {Martin-Luther-Universit\"{a}t},
 address	= {Halle-Wittenberg, Germany},
 year		= 1995}

@article{Schl93,
 author		= {T. Schlick},
 title		= {Modified {C}holesky factorizations for sparse
		   preconditioners},
 journal	= SISC,
 volume		= 14, number = 2, pages = {424--445}, year = 1993}

@article{SchnEsko91,
 author		= {R. B. Schnabel and E. Eskow},
 title		= {A new modified {C}holesky factorization},
 journal	= SISC,
 volume		= 11, number = 6, pages = {1136--1158}, year = 1991}

@article{SchnEsko99,
 author		= {R. B. Schnabel and E. Eskow},
 title		= {A revised modified {C}holesky factorization},
 journal        = SIOPT,
 number         = 9, volume = 4, pages = {1064--1081}, year = 1999}

@article{SchnKoonWeis85,
 author		= {R. B. Schnabel and J. E. Koontz and B. E. Weiss},
 title		= {A modular system of algorithms for unconstrained
		   minimization},
 journal	= {ACM Transactions on Mathematical Software},
 volume		= 11, number = 4, pages = {419--440}, year = 1985,
 abstract	= {We describe a new package, UNCMIN, for finding a local
		   minimizer of a real valued function of more than one
		   variable. The novel feature of UNCMIN is that it is a
		   modular system of algorithms, containing three different
		   step selection strategies (line search, dogleg, and optimal
		   step) that may be combined with either analytic or finite
		   difference gradient evaluation and with either analytic,
		   finite difference, or BFGS Hessian approximation. We
		   present the results of a comparison of the three step
		   selection strategies on the problems in
		   \citebb{MoreGarbHill81} in two separate cases: using finite
		   difference gradients and Hessians, and using finite
		   difference gradients with BFGS Hessian approximations. We
		   also describe a second package, REVMIN, that uses
		   optimization algorithms identical to UNCMIN but obtains
		   values of user-supplied functions by reverse communication.},
 summary	= {UNCMIN is a modular system of algorithms for optimization
		   containing three different step selection strategies
		   (linesearch, dogleg, and optimal step) that may be combined
		   with either analytic or finite difference gradient
		   evaluation and with either analytic, finite difference, or
		   BFGS Hessian approximation. The results of a comparison of
		   the three step selection strategies on the problems in
		   \citebb{MoreGarbHill81} are compared when using finite
		   difference gradients and Hessians, or finite difference
		   gradients with BFGS Hessian approximations. A second
		   package, REVMIN, that uses optimization algorithms
		   identical to UNCMIN but obtains values of user-supplied
		   functions by reverse communication is also described.}}

@article{SchoStoh99,
 author		= {S. Scholtes and M. St\"{o}hr},
 title		= {Exact penalization of mathematical programs with
		   equilibrium constraints},
 journal	= SICON,
 volume		= 37, number = 2, pages = {617--652}, year = 1999,
 abstract	= {We study theoretical and computational aspects of an exact
		   penalization approach to mathematical programs with
		   equilibrium constraints (MPEC). In the first part, we prove
		   that a Mangasarian-Fromowitz type condition ensures the
		   existence of a stable local error bound at the root of a
		   real-valued nonnegative piecewise smooth function. A
		   specification to nonsmooth formulations of equilibrium
		   constraints, e.g. complementarity conditions or normal
		   equations, provides conditions which guarantee the
		   existence of a nonsmooth exact penalty function for MPECs.
		   In the second part, we study a trust region minimization
		   method for a class of composite nonsmooth functions which
		   comprises exact penalty functions arising from MPECs. We
		   prove a global convergence result for the general method
		   and incorporate a penalty update rule. A further
		   specification results in an SQP trust region method for
		   MPECs based on an $\ell_1$ penalty function.},
 summary	= {Theoretical and computational aspects of an exact
		   penalization approach to mathematical programs with
		   equilibrium constraints (MPEC) are studied. It is 
		   shown that a Mangasarian-Fromowitz type condition ensures
		   the existence of a stable local error bound at the root of
		   a real-valued non-negative piecewise smooth function. A
		   specification to non-smooth formulations of equilibrium
		   constraints, e.g. complementarity conditions or normal
		   equations, then provides conditions which guarantee the
		   existence of a non-smooth exact penalty function for MPECs.
		   A trust-region minimization method for a class of composite
		   non-smooth functions is then presented, which comprises
		   exact penalty functions arising from MPECs. Global
		   convergence is proved and a penalty update rule is
		   described. A further specification results in an SQP
		   trust-region method for MPECs based on an $\ell_1$
		   penalty function.}}
		   
@article{SchrZowe92,
 author		= {H. Schramm and J. Zowe},
 title		= {A version of the bundle idea for minimizing a nonsmooth
		   function: conceptual idea, convergence analysis, numerical
		   results},
 journal	= SIOPT,
 volume		= 2, number = 1, pages = {121--152}, year = 1992,
 abstract	= {During recent years various proposals for the minimization
		   of a nonsmooth functional have been made. Amongst these,
		   the bundle concept turned out to be an especially fruitful
		   idea. Based on this concept, a number of authors have
		   developed codes that can successfully deal with nonsmooth
		   problems. The aim of the paper is to show that, by adding
		   some features of the trust-region philosophy to the bundle
		   concept, the end result is a distinguished member of the
		   bundle family with a more stable behaviour than some other
		   versions. The reliability and efficiency of this code is
		   demonstrated on the standard academic examples and on some
		   real-life problems},
 summary	= {An stable algorithm of the bundle family is obtained for
		   solving non-smooth minimization problems by adding some
		   features of the trust-region philosophy to the bundle
		   concept. The reliability and efficiency of the
		   corresponding code is demonstrated on the standard academic
		   examples and on some real-life problems.}}
 
@article{SchwTill89,
 author		= {H. Schwetlick and V. Tiller},
 title		= {Nonstandard Scaling Matrices for Trust Region
		   {G}auss-{N}ewton Methods},
 journal	= SISSC,
 volume		= 10, number = 4, pages = {654--670}, year = 1989,
 abstract	= {For solving large nonlinear problems via the trust-region
		   Gauss-Newton methods, nonstandard scaling matrices are
		   proposed for scaling the norm of the step. The scaling
		   matrices are rectangular, of full rank, and contain a block
		   of the Jacobian matrix of the residual function. Three
		   types of such matrices are investigated. The corresponding
		   trust region methods are shown to have qualitatively the
		   same convergence properties as the standard method.
		   Nonstandard scaling matrices are especially intended for
		   solving large and structured problems such as orthogonal
		   distance regression or surface fitting. Initial
		   computational experience suggests that for such problems
		   the proposed scaling implies sometimes a modest increase in
		   the number of iterations but reduces overall computational
		   cost.},
 summary	= {Non-standard scaling matrices are proposed for scaling the
		   norm of the step in the solution of large nonlinear
		   problems via the trust-region Gauss-Newton methods. The
		   scaling matrices are rectangular, of full rank, and contain
		   a block of the Jacobian matrix of the residual function.
		   Three types of such matrices are investigated. The
		   corresponding trust-region methods have
		   qualitatively the same convergence properties as the
		   standard method. Non-standard scaling matrices are
		   especially intended for solving large and structured
		   problems such as orthogonal distance regression or surface
		   fitting. Initial computational experience suggests that for
		   such problems the proposed scaling sometimes implies a
		   modest increase in the number of iterations but reduces
		   overall computational cost.}}

@phdthesis{Sebu92b,
 author		= {Ch. Sebudandi},
 title		= {Algorithmic developments in seismic tomography},
 school		= FUNDP, address = FUNDP-ADDRESS,
 year		= 1992}

@article{SebuToin92,
 author		= {Ch. Sebudandi and Ph. L. Toint},
 title		= {Nonlinear optimization for seismic travel time tomography},
 journal	= {Geophysical Journal International},
 volume		= 115, pages = {929--940}, year = 1993,
 abstract	= {This paper presents a non-linear algorithmic approach for
		   seismic traveltime. It is based on large-scale optimization
		   using non-linear least-squares and trust-region methods.
		   These methods provide a natural way to stabilize algorithms
		   based on Newton's iteration for non-linear minimization.
		   They also correspond to an alternative (and often more
		   efficient) view of the Levenberg-Marquardt method.
		   Numerical experience on synthetic data and on real
		   borehole-to-borehole problems are presented. In particular,
		   results produced by the algorithms are compared with those
		   of Ivansson (1985) for the Kr\aa m\aa la experiment.},
 summary	= {A nonlinear algorithm for seismic traveltime analysis is
		   presented, based on large-scale nonlinear least-squares
		   and trust-region methods. Numerical experience on synthetic
		   data and on real borehole-to-borehole problems is
		   presented. Results produced by the algorithms are compared
		   with those of Ivansson (1985) for the Kr\aa m\aa la
		   experiment.}}

@article{Semp97,
 author		= {J. Semple},
 title		= {Optimality conditions and solution procedures for
		   nondegenerate dual-response systems},
 journal	= {IIE Transactions},
 volume		= 29, number = 9, pages = {743-752}, year = 1997,
 abstract	= {This paper investigates the dual-response problem in the
		   case where the response functions are nonconvex
		   (nonconcave) quadratics and the independent variables
		   satisfy a radial bound. Sufficient conditions for a global
		   optimum are established and shown to generalize to the
		   multi-response case. It is then demonstrated that the
		   sufficient conditions may not hold if the problem is
		   'degenerate'. However, if the problem is nondegenerate, it
		   is shown that the sufficient conditions are necessarily
		   satisfied by some stationary point. In this case, a
		   specialized algorithm (DRSALG) is shown to locate the
		   global optimum in a finite number of steps. DRSALG will
		   also identify the degenerate case and pinpoint the location
		   where degeneracy occurs. The algorithm is easy to implement
		   from the standpoint of code development, and we illustrate
		   our elementary version on a well-studied dual-response
		   example from quality control.},
 summary	= {The dual-response problem in the case where the response
		   functions are non-convex (non-concave) quadratics and the
		   independent variables satisfy a radial bound is
		   investigated. Sufficient conditions for a global optimum
		   are established and generalized to the multi-response case.
		   It is demonstrated that the sufficient conditions may not
		   hold if the problem is ``degenerate''. However, if the
		   problem is non-degenerate, the sufficient conditions are
		   necessarily satisfied by some stationary point. In this
		   case, a specialized algorithm (DRSALG) locates
		   the global optimum in a finite number of steps. DRSALG also
		   identifies the degenerate case and pinpoints the location
		   where degeneracy occurs. The algorithm is easy to implement,
		   and is illustrated  on a well-studied dual-response 
                   example from quality control.}}

@phdthesis{Shah96,
 author		= {J. S. Shahabuddin},
 title		= {Structured trust-region algorithms for the minimization of
		   nonlinear functions},
 school		= CS-CORNELL, address = CORNELL-ADDRESS,
 year		= 1996,
 summary	= {Trust-region algorithms are a popular and successful class
		   of tools for the solution of nonlinear, non-convex
		   optimization problems. The basic trust-region algorithm is
		   extended so that it takes advantage of partial separability
		   to solve such large-scale problems in an efficient way. It
		   aims at simplifying the proposal of
		   \citebb{ConnGoulSartToin96a} in the case where no
		   constraints are imposed in the problem. Three related
		   approaches of ``multiple''or ``structured'' trust regions
		   are proposed. Convergence results are presented for them in
		   the unconstrained case. Some computational results are also
		   discussed, in which the three approaches are compared.}}

@article{Shan70,
 author		= {D. F. Shanno},
 title		= {Conditioning of Quasi-{N}ewton Methods For Function
		   Minimization},
 journal	= MC,
 volume		= 24, pages = {647--657}, year = 1970}

@article{Shan78b,
 author		= {D. F. Shanno},
 title		= {Conjugate gradient methods with inexact searches},
 journal	= MOR,
 volume		= 3, pages = {244--256}, year = 1978}

@misc{Shan99,
 author         = {D. F. Shanno},
 title          = {Topics in Implementing an Interior Point Method for
                   Nonconvex Nonlinear Programming}, 
 howpublished   = {Presentation at the First Workshop on Nonlinear
                   Optimization ``Interior-Point and Filter Methods'',
                   Coimbra, Portugal},
 year           = 1999}

@book{Shef85,
 author		= {Y. Sheffi},
 title		= {Urban Transportation Networks},
 publisher	= PH, address = PH-ADDRESS,
 year		= 1985}

@article{ShulSchnByrd85,
 author		= {G. A. Shultz and R. B. Schnabel and R. H. Byrd},
 title		= {A family of trust-region-based algorithms for unconstrained
		   minimization with strong global convergence properties},
 journal	= SINUM,
 volume		= 22, number = 1, pages = {47--67}, year = 1985,
 abstract	= {This paper has two aims: to exhibit very general conditions
		   under which members of a broad class of unconstrained
		   minimization algorithms are globally convergent in a strong
		   sense, and to propose several new algorithms that use
		   second derivative information and achieve such convergence.
		   In the first part of the paper, we present a general
		   trust-region-based algorithm schema that includes an
		   undefined step selection strategy. We give general
		   conditions on the step selection strategy under which limit
		   points of the algorithm will satisfy first and second order
		   necessary conditions for unconstrained minimization. Our
		   algorithm schema is sufficiently broad to include line
		   search algorithms as well. Next, we show that a wide range
		   of step selection strategies satisfy the requirements of
		   our convergence theory. This leads us to propose several
		   new algorithms that use second derivative information and
		   achieve strong global convergence, including an indefinite
		   line search algorithm, several indefinite dogleg algorithms
		   and a modified ``optimal-step'' algorithm. Finally, we
		   propose an implementation of one such indefinite dogleg
		   algorithm.},
 summary	= {A general trust-region-based algorithm schema that includes
		   an undefined step selection strategy is presented. General
		   conditions on the step selection strategy under which limit
		   points  will satisfy first and second order
		   necessary conditions are
		   given. The algorithm schema is sufficiently broad to
		   include linesearch methods as well. It is shown that a wide
		   range of step selection strategies satisfy the requirements
		   of the convergence theory, and several algorithms that use
		   second derivative information and achieve strong global
		   convergence are proposed. These include an indefinite
		   linesearch algorithm, several indefinite dogleg algorithms
		   and a modified ``optimal-step'' algorithm. An
		   implementation of one such indefinite dogleg algorithm is
		   proposed.}}

@inproceedings{SimaShan97,
 author      	= {E. M. Simantiraki and D. F. Shanno},
 title		= {An Infeasible-Interior-Point Method for Linear
                   Complementarity Problems},
 crossref       = {DuffWats97}, pages = {339--362}}

@article{Smal83,
 author		= {S. Smale},
 title		= {On the average number of steps of the simplex method of
		   linear programming},
 journal	= MP,
 volume		= 27, number = 3, pages = {241--262}, year = 1983}

@article{SmitBowe93,
 author		= {R. C. Smith and K. L. Bowers},
 title		= {{S}inc-{G}alerkin Estimation of Diffusivity in Parabolic
		   Problems},
 journal	= {Inverse Problems},
 volume		= 9, number = 1, pages = {113--135}, year = 1993,
 abstract	= {A fully Sinc-Galerkin method for the numerical recovery of
		   spatially varying diffusion coefficients in linear
		   parabolic partial differential equations is presented.
		   Because the parameter recovery problems are inherently
		   ill-posed, an output error criterion in' conjunction with
		   Tikhonov regularization is used to formulate them as
		   infinite-dimensional minimization problems. The forward
		   problems are discretized with a sinc basis in both the
		   spatial and temporal domains thus yielding an approximate
		   solution which displays an exponential convergence rate and
		   is valid on the infinite time interval. The minimization
		   problems are then solved via a quasi-Newton/trust region
		   algorithm. The L-curve technique for determining an
		   appropriate value of the regularization parameter is
		   briefly discussed, and numerical examples are given which
		   demonstrate the applicability of the method both for
		   problems with noise-free data as well as for those whose
		   data contain white noise.},
 summary	= {A fully Sinc-Galerkin method for the numerical recovery of
		   spatially varying diffusion coefficients in linear
		   parabolic partial differential equations is presented.
		   Because the parameter recovery problems are inherently
		   ill-posed, an output error criterion in conjunction with
		   Tikhonov regularization is used to formulate them as
		   infinite-dimensional minimization problems. The forward
		   problems are discretized with a sinc basis in both the
		   spatial and temporal domains thus yielding an approximate
		   solution which displays an exponential convergence rate and
		   is valid on the infinite time interval. The minimization
		   problems are then solved via a quasi-Newton/trust-region
		   algorithm. The L-curve technique for determining an
		   appropriate value of the regularization parameter is
		   briefly discussed, and numerical examples illustrate the
		   applicability of the method both for problems with
		   noise-free data as well as for those whose data contain
		   white noise.}}

@article{Sore82,
 author		= {D. C. Sorensen},
 title		= {{N}ewton's Method with a Model Trust-Region Modification},
 journal	= SINUM,
 volume		= 19, number = 2, pages = {409--426}, year = 1982,
 abstract	= {A modified Netwon method for unconstrained minimization is
		   presented and analyzed. The modification is based upon the
		   model trust region approach. This report contains a
		   thorough analysis of the locally constrained quadratic
		   minimizations that arise as subproblems in the modified
		   Newton iteration. Several promising alternatives are
		   presented for solving these subproblems in ways that
		   overcome certain theoretical difficulties exposed by the
		   analysis. Very strong convergence results are presented
		   concerning the minimization algorithm. In particular, the
		   explicit use of second order information is justified by
		   demonstrating that the iterates converge to a point which
		   satisfies the second order necessary conditions for
		   minimization. With the exception of very pathological cases
		   this occurs whenever the algorithm is applied to problems
		   with continuous second partial derivatives.},
 summary	= {A modified Netwon method for unconstrained minimization is
		   presented and analyzed. The modification is based upon the
		   model trust-region approach. A thorough analysis of the
		   locally constrained quadratic minimizations that arise as
		   subproblems in the modified Newton iteration is given.
		   Several promising alternatives are presented for solving
		   these subproblems in ways that overcome certain theoretical
		   difficulties exposed by the analysis. Very strong
		   convergence results are presented concerning the
		   minimization algorithm. In particular, the explicit use of
		   second order information is justified by demonstrating that
		   the iterates converge to a point which satisfies the second
		   order necessary conditions for minimization. With the
		   exception of very pathological cases this occurs whenever
		   the algorithm is applied to problems with continuous second
		   partial derivatives.}}

@inproceedings{Sore82b,
 author		= {D. C. Sorensen},
 title		= {Trust Region Methods for Unconstrained Optimization},
 crossref	= {Powe82}, pages = {29--39},
 summary	= {The basic trust-region approach to safeguarding Newton-like
		   methods for unconstrained optimization is discussed.}}

@article{Sore97,
 author		= {D. C. Sorensen},
 title		= {Minimization of a Large-Scale Quadratic Function subject to
		   a Spherical Constraint},
 journal	= SIOPT,
 volume		= 7, number = 1, pages = {141--161}, year = 1997,
 abstract	= {An important problem in linear algebra and optimization is
		   the Trust-Region Subproblem: Minimize a quadratic function
		   subject to an ellipsoidal or spherical constraint. This
		   basic problem has several important large scale
		   applications including seismic inversion and forcing
		   convergence in optimization methods. Existing methods to
		   solve the trust-region subproblem require matrix
		   factorizations, which are not feasible in large scale
		   setting. This paper presents an algorithm for solving the
		   large scale trust-region subproblem that requires a fixed
		   size limited storage proportional to order of the quadratic
		   and that relies only on matrix-vector products. The
		   algorithm recasts the trust-region subproblem in terms of a
		   parametrized eigenvalue problem and adjusts the parameter
		   with a superlinearly convergent iteration to find the
		   optimal solution from the eigenvector of the parametrized
		   problem. Only the smallest eigenvalue and corresponding
		   eigenvector of the parametrized problem needs to be
		   computed. The Implicitly Restarted Lanczos Method is
		   well-suited to this subproblem.},
 summary	= {An algorithm is presented for solving the large scale
		   trust-region subproblem that requires a fixed size limited
		   storage proportional to order of the quadratic and that
		   relies only on matrix-vector products. The algorithm
		   recasts the trust-region subproblem in terms of a
		   parametrized eigenvalue problem and adjusts the parameter
		   with a superlinearly convergent iteration to find the
		   optimal solution from the eigenvector of the parametrized
		   problem. Only the smallest eigenvalue and corresponding
		   eigenvector of the parametrized problem needs to be
		   computed. The Implicitly Restarted Lanczos Method is
		   well-suited to this subproblem.}}

@article{StanSnym93,
 author		= {N. Stander and J. A. Snyman},
 title		= {A new first-order interior feasible direction method for
		   structural optimization},
 journal	= {International Journal for Numerical Methods in Engineering},
 volume		= 36, number = 23, pages = {4009--4025}, year = 1993}

@article{Stei83a,
 author		= {T. Steihaug},
 title		= {The conjugate gradient method and trust regions in large
		   scale optimization},
 journal	= SINUM,
 volume		= 20, number = 3, pages = {626--637}, year = 1983,
 abstract	= {Algorithms based on trust regions have been shown to be
		   robust methods for unconstrained optimization problems. All
		   existing methods, either based on the dogleg strategy or
		   \citebb{Hebd73}--\citebb{More78} iterations, require the
		   solution of system of linear equations. In large scale
		   optimization this may be prohibitively expensive. It is
		   shown in this paper that an approximate solution of the
		   trust region problem may be found by the preconditioned
		   conjugate gradient method. This may be regarded as a
		   generalized dogleg technique where we asymptotically take
		   the inexact quasi-Newton step. We also show that we have
		   the same properties as existing methods based on the dogleg
		   strategy using an approximate Hessian.},
 summary	= {It is shown that an approximate solution of the
		   trust-region problem may be found by the preconditioned
		   conjugate gradient method. This may be regarded as a
		   generalized dogleg technique where asymptotically the
		   inexact quasi-Newton step is taken. The resulting algorithm
		   has the same properties as existing methods 
		   based on the dogleg strategy using an approximate Hessian.}}

@article{SterWolk94,
 author		= {R. J. Stern and H. Wolkowicz},
 title		= {Trust region problems and nonsymetric eigenvalue
		   perturbations},
 journal	= SIMAA,
 volume		= 15, number = 3, pages = {775--778}, year = 1994,
 abstract	= {A characterization is given for the spectrum of a symmetric
		   matrix to remain real after a nonsymmetric sign-restricted
		   border perturbation, including the case where the
		   perturbation is skew-symmetric. The characterization is in
		   terms of the stationary points of a quadratic function on
		   the unit sphere. This yields interlacing relationships
		   between the eigenvalues of the original matrix and those of
		   the perturbed matrix. As a result of the linkage between
		   the perturbation and stationarity problems, new theoretical
		   insights are gained for each. Applications of the main
		   results include a characterization of those matrices that
		   are exponentially nonnegative with respect to the
		   n-dimensional ice-cream cone, which in turn leads to a
		   decomposition theorem for such matrices. In addition,
		   results are obtained for nonsymmetric matrices regarding
		   interlacing and majorization.},
 summary	= {A characterization is given for the spectrum of a symmetric
		   matrix to remain real after a non-symmetric sign-restricted
		   border perturbation, including the case where the
		   perturbation is skew-symmetric. The characterization is in
		   terms of the stationary points of a quadratic function on
		   the unit sphere. This yields interlacing relationships
		   between the eigenvalues of the original matrix and those of
		   the perturbed matrix. Applications include a
		   characterization of matrices that are exponentially
		   non-negative with respect to the $n$-dimensional ice-cream
		   cone, which leads to a decomposition theorem for
		   such matrices. Results are obtained for
		   non-symmetric matrices regarding interlacing and
		   majorization.}}

@article{SterWolk95,
 author		= {R. J. Stern and H. Wolkowicz},
 title		= {Indefinite Trust Region Subproblems and Nonsymmetric
		   Eigenvalue Perturbations},
 journal	= SIOPT,
 volume		= 5, number = 2, pages = {286--313}, year = 1995,
 abstract	= {This paper extends the theory of trust region subproblems
		   in two ways: (i) it allows indefinite inner products in the
		   quadratic constraint, and (ii) it uses a two-sided (upper
		   and lower bound) quadratic constraint. Characterizations of
		   optimality are presented that have no gap between necessity
		   and sufficiency. Conditions for the existence of solutions
		   are given in terms of the definiteness of a matrix pencil.
		   A simple dual program is introduced that involves the
		   maximization of a strictly concave function on an interval.
		   The dual program simplifies the theory and algorithms for
		   trust region subproblems. It also illustrates that the
		   trust region subproblems are implicit convex programming
		   problems, and thus explains why they are so tractable. The
		   duality theory also provides connections to eigenvalue
		   perturbation theory. Trust region subproblems with zero
		   linear term in the objective function correspond to
		   eigenvalue problems, and adding a linear term in the
		   objective function is seen to correspond to a perturbed
		   eigenvalue problem. Some eigenvalue interlacing results are
		   presented.},
 summary	= {The theory of trust-region subproblems is extended in two
		   ways: (i) indefinite inner products in the quadratic
		   constraint are allowed, and (ii) a two-sided (upper and
		   lower bound) quadratic constraint is used.
		   Characterizations of optimality are presented that have no
		   gap between necessity and sufficiency. Conditions for the
		   existence of solutions are given in terms of the
		   definiteness of a matrix pencil. A simple dual program is
		   introduced that involves the maximization of a strictly
		   concave function on an interval. The dual program
		   simplifies the theory and algorithms for trust-region
		   subproblems. It also illustrates that they are implicit
		   convex programming problems, and thus explains why they are
		   so tractable. The duality theory provides connections to
		   eigenvalue perturbation theory. Trust-region subproblems
		   with zero linear term in the objective function correspond
		   to eigenvalue problems, and adding a linear term in the
		   objective function is seen to correspond to a perturbed
		   eigenvalue problem. Some eigenvalue interlacing results are
		   presented.}}

@article{Stew67,
 author		= {G. W. Stewart},
 title		= {A Modification of {D}avidon's Minimization Method to Accept
		   Difference Approximations of Derivatives},
 journal	= {Journal of the ACM},
 volume		= 14, year = 1967}

@inproceedings{Stoe83,
 author		= {J. Stoer},
 title		= {Solution of Large Linear Systems of Equations by Conjugate
		   Gradient Type Methods},
 crossref	= {BachGrotKort83}, pages = {540--565}}

@phdthesis{Stoh99,
 author         = {M. St\"{o}hr},
 title          = {Nonsmooth trust-region methods and their applications to 
                   mathematical programs with equilibrium constraints},
 school         = {Faculty of Mathematics, University of Karlsruhe},
 address        = {Karlsruhe, Germany},
 year           = 1999,
 abstract       = {(none)},
 summary        = {A trust-region method for the solution of mathematical 
                   programs with equilibrium constraints (MPEC) is proposed 
                   and analyzed. It makes use of exact penalty functions 
                   arising from the MPECs formulation. A variant of the
                   algorithm by \citebb{SchoStoh99} is discussed that
                   uses the concept of Cauchy point rather than requiring
                   a model decrease proportional to that obtained at the
                   global solution of the trust-region subproblem. Global
		   convergence is proved and some numerical tests illustrate
                   the method.}}

@inproceedings{StudLuth97,
 author         = {G. Studer and H.-J. L\"{u}thi},
 title          = {Maximum loss for risk measurement of portfolios},
 booktitle      = {Operations Research Proceedings 1996: Selected Papers of 
                   the Symposium on Operations Research (SOR 96)}, 
 editor         = {U. Zimmermann and U. Derigs and W. Gaul and 
		   R. H. Mohring and K. P. Schuster},
 publisher     	= SPRINGER, address = SPRINGER-ADDRESS,
 pages          = {386--391}, year = 1997,
 abstract	= {Effective risk management requires adequate risk
		   measurement. A basic problem herein is the quantification
		   of market risks: what is the overall effect on a portfolio
		   if market rates change? The first chapter gives a brief
		   review of the standard risk measure "Value-At-Risk" (VAR)
		   and introduces the concept of "Maximum Loss" (ML) as a
		   method for identifying the worst case in a given scenario
		   space, called "Trust Region". Next, a technique for
		   calculating efficiently ML for quadratic functions is
		   described; the algorithm is based on the
		   Levenberg-Marquardt theorem, which reduces the high
		   dimensional optimization problem to a one dimensional root
		   finding. Following this, the idea of the "Maximum Loss
		   Path" is presented: repetitive calculation of ML for a
		   growing trust region leads to a sequence of worst cases,
		   which form a complete path. Similarly, the paths of
		   "Maximum Profit" (MP) and "Expected Value" (EV) can be
		   determined; the comparison of them permits judgments on
		   the quality of portfolios. These concepts are also
		   applicable to non-quadratic portfolios by using "Dynamic
		   Approximations", which replace arbitrary profit and loss
		   functions with a sequence of quadratic functions. Finally,
		   the idea of "Maximum Loss Distribution" is explained. The
		   distributions of ML and MP can be obtained directly from
		   the ML and MP paths. They lead to lower and upper bounds of
		   VAR and allow statements about the spread of ML and MP.},
 summary	= {A brief review of the standard risk measure "Value-At-Risk"
		   (VAR) is given and the concept of "Maximum Loss" (ML) for
		   identifying the worst case in a given scenario space, a
		   trust region, introduced. A technique for calculating
		   efficiently ML for quadratic functions is described; the
		   algorithm is based on the Levenberg-Morrison-Marquardt
		   theorem. The idea of the "Maximum Loss Path" is presented.
		   Repetitive calculation of ML for a growing trust region
		   leads to a sequence of worst cases, which form a complete
		   path. Similarly, the paths of "Maximum Profit" (MP) and
		   "Expected Value" (EV) can be determined; the comparison of
		   them permits judgments on the quality of portfolios. These
		   concepts are applicable to non-quadratic portfolios by
		   using "Dynamic Approximations", which replace arbitrary
		   profit and loss functions with a sequence of quadratic
		   functions. The idea of "Maximum Loss Distribution" is
		   explained. The distributions of ML and MP can be obtained
		   directly from the ML and MP paths, lead to lower and upper
		   bounds of VAR and allow statements about the spread of ML
		   and MP.}}

@article{Stra91,
 author		= {Z. Strako\v{s}},
 title		= {On the real convergence rate of the conjugate gradient
		   method},
 journal	= LAA,
 volume		= {154-156}, pages = {535--549}, year = 1991}

@article{Sun96,
 author		= {L. P. Sun},
 title		= {A restricted trust region method with supermemory for
		   unconstrained optimization},
 journal	= JCM,
 volume		= 14, number = 3, pages = {195--202}, year = 1996,
 abstract	= {A new method for unconstrained optimization problems is
		   presented. It belongs to the class of trust-region method,
		   in which the descent direction is sought by using the trust
		   region steps within the restricted subspace. Because this
		   subspace can be specified to include information about
		   previous steps, the method is also related to a supermemory
		   descent method without performing multiple dimensional
		   searches. Trust region methods have attractive global
		   convergence property. Since the method possesses the
		   characteristics of both the trust region methods and the
		   supermemory descent methods, it is endowed with rapidly
		   convergence. Numerical tests illustrate this point.},
 summary	= {A trust-region method for unconstrained optimization
		   problems is presented, in which the descent direction is
		   sought by using the trust-region steps within a
		   restricted subspace. Because this subspace can be specified
		   to include information about previous steps, the method is
		   also related to a supermemory descent methods. It is endowed
		   with rapidly convergence, as illustrated by numerical
		   tests.}}

@article{Sun96b,
 author		= {W. Sun},
 title		= {Optimization methods for nonquadratic model},
 journal	= {Asia-Pacific Journal of Operational Research},
 volume		= 13, number = 1, pages = {43--63}, year = 1996}
% abstract	= {In this paper we review the state of the art and future
%		   development on non-quadratic model optimization (NQMO).
%		   Optimization methods based on the non-quadratic model are
%		   more interesting than ones based on the quadratic model
%		   because they have more interpolation information and better
%		   approximation effect, especially for ill-conditioned
%		   functions or functions with strong non-quadratic behaviour.
%		   The main non-quadratic model methods include conic model
%		   methods, homogeneous model methods, nonlinear scaling model
%		   methods, tensor model methods and trust region model
%		   methods. We think that further study of NQMO is necessary,
%		   the area shows great potential and it is interesting.},
% summary	= {The state of the art and future development on
%		   non-quadratic model optimization (NQMO) is reviewed.
%		   Optimization methods based on the non-quadratic model are
%		   more interesting than ones based on the quadratic model
%		   because they have more interpolation information and better
%		   approximation effect, especially for ill-conditioned
%		   functions or functions with strong non-quadratic behaviour.
%		   The main non-quadratic models include conic models,
%		   homogeneous models, nonlinear scaling models,
%		   tensor models and trust-region models.}

@article{Sun93,
 author		= {J. Sun},
 title		= {A convergence proof for an affine-scaling algorithm for
		   convex quadratic programming without nondegeneracy
		   assumptions},
 journal	= MP,
 volume		= 60, number = 1, pages = {69--79}, year = 1993}

@article{Sun97,
 author		= {J. Sun},
 title		= {On piecewise quadratic {N}ewton and trust-region problems},
 journal	= MP,
 volume		= 76, number = 3, pages = {451--468}, year = 1997,
 abstract	= {Some recent algorithms for nonsmooth optimization require
		   solutions to certain piecewise quadratic programming
		   subproblems. Two types of subproblems are considered in
		   this paper. The first type seeks the minimization of a
		   continuously differentiable and strictly convex piecewise
		   quadratic function subject to linear equality constraints.
		   We prove that a nonsmooth version of Newton's method is
		   globally and finitely convergent in this case. The second
		   type involves the minimization of a possibly nonconvex and
		   nondifferentiable piecewise quadratic function over a
		   Euclidean ball. Characterizations of the global minimizer
		   are studied under various conditions. The results extend a
		   classical result on the trust region problem.},
 summary	= {Some algorithms for non-smooth optimization require the
		   solutions to certain piecewise quadratic programming
		   subproblems. Two types of subproblems are considered. The
		   first uses the minimization of a continuously
		   differentiable and strictly convex piecewise quadratic
		   function subject to linear equality constraints. 
		   A non-smooth version of Newton's method is
		   globally and finitely convergent in this case. The second
		   type involves the minimization of a possibly non-convex and
		   non-differentiable piecewise quadratic function over a
		   Euclidean ball. Characterizations of the global minimizer
		   are studied under various conditions.}}

@article{SunRued93,
 author         = {J.-Q. Sun and K. Ruedenberg},
 title          = {Quadratic steepest descent on potential energy surfaces. 
                   {I}. {B}asic formalism and quantitative assessment},
 journal        = {Journal of Chemical Physics},
 volume         = 99, number = 7, pages = {5257--5268}, year = 1993,
 abstract       = {A novel second-order algorithm is formulated for
                   determining steepest-descent lines on potential
                   energy surfaces. The reaction path is deduced from
                   successive exact steepest-descent lines of local
                   quadratic approximations to the surface. At each
                   step, a distinction is made between three points: the
                   center for the local quadratic Taylor expansion of
                   the surface, the junction of the two adjacent local
                   steepest-descent line approximations, and the
                   predicted approximation to the true steepest-descent
                   line. This flexibility returns a more efficient yield
                   from the calculated information and increases the
                   accuracy of the local quadratic approximations by
                   almost an order of magnitude. In addition, the step
                   size is varied with the curvature and, if desired,
                   can be readjusted by a trust region
                   assessment. Applications to the Gonzalez-Schlegel and
                   the Muller-Brown surfaces show the method to compare
                   favorably with existing methods. Several measures are
                   given for assessing the accuracy achieved without
                   knowledge of the exact steepest-descent line. The
                   optimal evaluation of the predicted gradient and
                   curvature for dynamical applications is discussed.},
 summary        = {A second-order algorithm is formulated for
                   determining steepest-descent lines on potential
                   energy surfaces, in which the step size is varied with the
		   curvature and, if desired, readjusted by a trust region
                   assessment. Applications to the Gonzalez-Schlegel and
                   the Muller-Brown surfaces show the method to behave well.
                   Several measures are given for assessing the accuracy
		   achieved without knowledge of the exact steepest-descent
		   line. The optimal evaluation of the predicted gradient and
                   curvature for dynamical applications is discussed.}}


@misc{SunYuan98,
 author         = {W. Sun and Y. Yuan},
 title          = {A Conic Model Trust Region Method for Nonlinearly
                   Constrained Optimization},
 howpublished	= {Presentation at the International Conference on Nonlinear
                   Programming and Variational Inequalities, Hong Kong},
 year           = 1998,
 abstract       = {In this paper we present conic trust region methods for
                   constrained optimization problems. We give necessary and
                   sufficient conditions for the solution of the associated
                   trust region subproblems.  Several equivalent variations
                   and their properties are discussed.  Some conic trust
                   region algorithms are constructed.  Finally, we establish
                   the global and local convergence of our algorithms},
 summary        = {Trust-region methods for constrained optimization using
                   conic models are considered, and necessary and sufficient
                   conditions given for the solution of several equivalent
                   formulations of the associated subproblems.  Convergence
                   properties of the resulting algorithm are established.}}

@article{SunaBele91,
 author		= {M. Sunar and A. D. Belegundu},
 title		= {Trust Region Methods for Structural Optimization Using
		   Exact 2nd-Order Sensitivity},
 journal	= {International Journal for Numerical Methods in Engineering},
 volume		= 32, number = 2, pages = {275--293}, year = 1991,
 abstract	= {The performance of multiplier algorithms for structural
		   optimization has been significantly improved by using trust
		   regions. The trust regions are constructed using analytical
		   second order sensitivity, and within this region, the
		   augmented Lagrangian $\phi$ is minimized subject to bounds.
		   Evaluation of first and second derivatives of $\phi$ by the
		   adjoint method does not require derivations of individual
		   (implicit) constraint functions, which makes the method
		   economical. Eight test problems are considered and a vast
		   improvement over previously used multiplier algorithms has
		   been noted. Also, the algorithm is robust with respect to
		   scaling, input parameters and starting designs.},
 summary	= {A trust-region method for structural
		   optimization is constructed using analytical
		   second order sensitivity. The augmented Lagrangian $\phi$
		   is minimized in this region subject to bounds. 
		   Evaluation of first and second derivatives of $\phi$ by the
		   adjoint method does not require derivations of individual
		   (implicit) constraint functions, which makes the method
		   economical. The algorithm is robust with respect to
		   scaling, input parameters and starting designs.}}

@book{Suth75,
 author		= {W. A. Sutherland},
 title		= {Introduction to Metric and Topological Spaces},
 publisher	= OUP, address = OUP-ADDRESS,
 year		= 1975}


%%% T %%%

@article{Tapi77,
 author		= {R. A. Tapia},
 title		= {Diagonalized multiplier methods and quasi-{N}ewton methods
		   for constrained optimization},
 journal	= JOTA,
 volume		= 22, pages = {135--194}, year = 1977}

@inproceedings{TappJala90,
 author         = {C. Tappayuthpijarn and J. Jalali},
 title          = {Loadflow solution by applying hybrid algorithm to the 
                   {N}ewton-{R}aphson method},
 booktitle      = {Proceedings of the American Power Conference, 
                   Illinois Institute of Technology, Chicago, IL, USA},
 pages          = {234--238}, year = 1990,
 abstract       = {The purpose of the hybrid method in solving power
                   flow problems is to improve the efficiency in
                   convergence of the existing Newton-Raphson method
                   (NR) when its close initial estimates are not
                   available. The method is based on interpolating
                   between the fast convergence standard Newton-Raphson
                   iteration and the method of steepest descent applied
                   to the sum of the square of mismatch $f_i(x)$. The
                   balance between these two methods is governed by
                   introducing the concept of the trust region to
                   restrict the step predicted by the classical method
                   to be in the quadratic region and to switch to the
                   steepest decent method that is better when the
                   initial starts are far from the solution. The concept
                   of trust radius and switching policies are given by
                   the author. Digital computer results and their
                   comparison of the 10 bus system, with different
                   initial starts, by the proposed method and by the
                   classical method are also given.},
 summary        = {A trust-region based method is described for enforcing
		   global convergence in solving power flow problems.}}


@article{Tana99,
 author		= {Y. Tanaka},
 title		= {A trust region method for semi-infinite programming 
                   problems },
 journal	= {International Journal of Systems Science},
 volume		= 30, number = 2, pages = {199--204}, year = 1999,
 abstract	= {We present a new successive quadratic programming (SQP) 
                   approach for semi-infinite programming problems with
                   a trust region technique. Numerical methods for
                   solving semi-infinite programming problems can be
                   divided into continuous methods and discretization
                   methods. We begin with a trust region method for
                   nonlinear programming problems which possesses a fast
                   and global convergence property and obviates the
                   Maratos effect which is an unfavourable phenomenon
                   that sometimes occurs for general SQP-type
                   approaches. Then we apply the method to discretized
                   semi-infinite programming problems by utilizing an
                   $L_{\infty}$-exact penalty function and
                   $\epsilon$-most-active constraints. The
                   $L_{\infty}$-exact penalty function is, in fact,
                   essential for continuity methods for semi-infinite
                   programming problems so as to maintain continuity, of
                   the exact penalty function, and enables the use of
                   epsilon-most-active constraints in discretized
                   semi-infinite programming problems. The results of
                   preliminary computational experiments demonstrate the
                   effectiveness of our approach for discretized
                   semi-infinite programming problems.},
 summary	= {A trust region SQP method, using second-order 
                   corrections, is applied to discretized
                   semi-infinite programming problems, using an
                   $L_{\infty}$-exact penalty function and
                   $\epsilon$-most-active constraints. 
                   Preliminary computational experiments demonstrate the
                   viability of this approach.}}
 
@article{TanaFukuHase87,
 author         = {Y. Tanaka and M. Fukushima and T. Hasegawa},
 title          = {Implementable $L_{\infty}$ penalty-function method 
                   for semi-infinite optimization},
 journal        = {International Journal of Systems Science},
 volume         = 18, number = 8, pages = {1563--1568}, year = 1987,
 abstract       = {This paper considers general nonlinear semi-infinite
                   programming problems and presents an implementable
                   method which employs an exact $L_{\infty}$
                   penalty function. Since the $L_{\infty}$ penalty
                   function is continuous even if the number of
                   representative constraints changes, trust-region
                   techniques may effectively be adopted to obtain
                   global convergence. Numerical results are given to
                   show the efficiency of the proposed algorithm.},
 summary        = {An implementable method for general nonlinear
		   semi-infinite programming problems is described, which
		   employs an exact $L_{\infty}$ penalty function. Since
	 	   this function is continuous even if the number of
                   representative constraints changes, trust-region
                   techniques may effectively be adopted to obtain
                   global convergence. Numerical results are given to
                   show the efficiency of the proposed algorithm.}}


@article{TanaFukuIbar88,
 author         = {Y. Tanaka and M. Fukushima and T. Ibaraki},
 title          = {A globally convergent SQP method for semi-infinite 
                   nonlinear optimization},
 journal        = JCAM,
 volume         = 23, number = 2, pages = {141--153}, year = 1988,
 abstract       = {A new approach for semi-infinite programming problems
                   is presented, which belongs to the class of
                   successive quadratic programming (SQP) methods with
                   trust region technique. The proposed algorithm
                   employs the exact L/sub infinity / penalty function
                   as a criterion function and incorporates an
                   appropriate scheme for estimating active
                   constraints. It is proved that the algorithm is
                   globally convergent under some assumptions. Numerical
                   experiments show that the algorithm is very promising
                   in practice.},
 summary        = {A trust-region SQP method for semi-infinite programming
                   is presented. The proposed algorithm
                   employs the exact $L_{\infty}$ penalty function
                   and incorporates a scheme for estimating active
                   constraints. It is proved to be
                   globally convergent. Numerical
                   experiments show that the algorithm is promising.}}

@article{Tebo97,
 author		= {M. Teboulle},
 title		= {Convergence of proximal-like algorithms},
 journal	= SIOPT,
 volume		= 6, number = 3, pages = {617--625}, year = 1997}

@article{Terp95,
 author		= {P. Terpolilli},
 title		= {Trust region method in nonsmooth optimization},
 journal	= {Comptes rendus de l'{A}cad\'{e}mie des {S}ciences,
		   s\'{e}rie {M}ath\'{e}matique},
 volume		= 321, number = 7, pages = {945--948}, year = 1995,
 abstract	= {In this note, a new framework for nonsmooth optimization is
		   introduced. We consider then an algorithm using trust
		   region stategy and prove some global convergence results.
		   We pay particular attention to the use of inexact local
		   models : actually, we give a convergence result in a
		   situation where local models are computed by a numerical
		   procedure.},
 summary	= {A framework for non-smooth optimization is introduced.
		   An algorithm using trust-region stategy is considered and
		   global convergence results are established. Particular
		   attention is paid to the use of inexact local models. A
		   convergence result is given in the situation where local
		   models are computed by a numerical procedure.}}

@phdthesis{Tern94,
 author		= {D. J. Ternet},
 title		= {A trust region algorithm for reduced {H}essian successive
		   quadratic programming},
 school		= {Department of Chemical Engineering, Carnegie Mellon
		   University},
 address	= {Pittsburgh, USA},
 year		= 1994,
 abstract	= {Successive Quadratic Programming (SQP) has become a powerful
		   tool for solving large-scale process optimization problems.
		   An SQP code has recently been developed at CMU to solve
		   nonlinear programming problems. Some areas of improvement
		   in the current algorithm include the introduction of a
		   barrier function to reduce the constraints, the development
		   of a sparse matrix version of the code for larger problems,
		   and the solution of a trust region constraint to the
		   solution of the quadratic programming (QP) subproblem. Of
		   these possible improvements, the trust region
		   implementation was chosen as the focus of this paper. The
		   Successive Quadratic Programming method of solving
		   nonlinear programming problems is reviewed, as well as the
		   role of line search and trust region methods within this
		   framework. A trust region was added to the current
		   algorithm to increase the algorithms robustness while
		   maintaining its superlinear convergence properties. The
		   benefits of combining a line search method with a trust
		   region method are also explained. A set of test problems
		   for the new algorithm are explained which motivates the need
		   for the addition of the trust region.},
 summary	= {An SQP algorithm for solving nonlinear programming problems
		   is reviewed, as well as the role of linesearch and
		   trust-region methods within this framework. A trust region
		   is added to the current algorithm to increase the
		   algorithms robustness while maintaining its superlinear
		   convergence properties. The benefits of combining a
		   linesearch method with a trust-region method are also
		   explained. A set of test problems are described which
		   motivate the need for the trust region.}}

@phdthesis{Thom75,
 author		= {S. Thomas},
 title		= {Sequential estimation techniques for quasi-{N}ewton
		   algorithms},
 school		= {Cornell University}, address = CORNELL-ADDRESS,
 year		= 1975}

@article{Tibs96,
 author		= {R. Tibshirani},
 title		= {Regression shrinkage and selection via the lasso},
 journal	= {Journal of the Royal Statistical Society B},
 volume		= 58, number = 1, pages = {267--288}, year = 1996}

@article{TinnWalk67,
 author		= {W. F. Tinney and J. W. Walker},
 title		= {Direct solution of sparse network equations by optimally
		   ordered triangular factorization},
 journal	= {Proceedings of the IEEE},
 volume		= 55, pages = {1801--1809}, year = 1967}

@article{Toin77a,
 author		= {Ph. L. Toint},
 title		= {On sparse and symmetric matrix updating subject to a linear
		   equation},
 journal	= MC,
 volume		= 31, number = 140, pages = {954--961}, year = 1977}

@article{Toin78,
 author		= {Ph. L. Toint},
 title		= {Some Numerical Result Using a Sparse Matrix Updating
		   Formula in Unconstrained Optimization},
 journal	= MC,
 volume		= 32, number = 143, pages = {839--851}, year = 1978}
%abstract       = {This paper presents a numerical comparison between
%                  algorithms for unconstrained optimization that take account
%                  of sparsity in the second derivative matrix of the
%                  objective function.  Some of the methods
%                  included in the comparison use difference approximation 
%                  schemes to evaluate the second derivative matrix and 
%                  other use an approximation to it which is updated regularly
%                  using the changes in the gradient.  These results show what
%                  method to use in what circumstances and also suggest 
%                  interesting future developments.}}

@article{Toin79,
 author		= {Ph. L. Toint},
 title		= {On the Superlinear Convergence of an Algorithm for Solving
		   a Sparse Minimization Problem},
 journal	= SINUM,
 volume		= 16, pages = {1036--1045}, year = 1979}

@inproceedings{Toin80a,
 author		= {Ph. L. Toint},
 title		= {Sparsity Exploiting Quasi-{N}ewton Methods for
		   Unconstrained Optimization},
 crossref	= {DixoSpedSzeg80}, pages = {65--90}}

@inproceedings{Toin81b,
 author		= {Ph. L. Toint},
 title		= {Towards an Efficient Sparsity Exploiting {N}ewton Method
		   for Minimization},
 booktitle	= {Sparse Matrices and Their Uses},
 editor		= {I. S. Duff},
 publisher	= AP, address = AP-ADDRESS,
 pages		= {57--88}, year = 1981,
 abstract	= {The paper surveys some recently proposed algorithms for
		   unconstrained minimization when second derivative of the
		   objective function is sparse. Updating and estimation
		   procedures are considered from the efficiency point of
		   view. Special attention is given to the case where the
		   Hessian has a band structure. A new strategy for the choice
		   of the step is also discussed and some numerical results on
		   a specially designed test function are presented.},
 summary	= {Recently proposed algorithms for unconstrained minimization
		   when second derivative of the objective function is sparse
		   are surveyed. Updating and estimation procedures are
		   considered from the efficiency point of view. Special
		   attention is given to the case where the Hessian has a band
		   structure. A strategy for the choice of the step using
		   truncated conjugate-gradients is also discussed and some
		   numerical results on a specially designed test function
		   are presented.}}

@techreport{Toin81f,
 author		= {Ph. L. Toint},
 title		= {Convergence properties of a class of minimization
		   algorithms that use a possibly unbounded sequence of
		   quadratic approximations},
 institution	= FUNDP, address = FUNDP-ADDRESS,
 number		= {81/1}, year = 1981,
 abstract	= {Global convergence results are established for a
		   trust-region like algorithm. At variance with previous
		   contributions, this theory does not make assumptions the
		   norm of the Hessian approximations, but rather on the
		   Rayleigh quotients of this approximation in certain
		   specific directions. This allows for the case where Hessian
		   approximations may become arbitrarily large provided they
		   remain reasonable in these directions.},
 summary	= {Global convergence results are established for a
		   trust-region algorithm without assumptions on the
		   norm of the Hessian approximations, but rather on the
		   Rayleigh quotients of this approximation in certain
		   directions. This allows for the case where Hessian
		   approximations may become arbitrarily large provided they
		   remain reasonable in these directions.}}

@techreport{Toin83b,
 author		= {Ph. L. Toint},
 title		= {User's Guide to the Routine {PSPMIN} for Solving Partially
		   Separable Bounded Optimization Problems},
 institution	= FUNDP, address = FUNDP-ADDRESS,
 number		= {83/1}, year = 1983}

@article{Toin83e,
 author		= {Ph. L. Toint},
 title		= {{VE08AD}, a routine for partially separable optimization
		   with bounded variables},
 journal	= {Harwell Subroutine Library},
 volume		= 2, year = 1983}

@article{Toin86b,
 author		= {Ph. L. Toint},
 title		= {On large scale nonlinear least squares calculations},
 journal	= SISSC,
 volume		= 8, number = 3, pages = {416--435}, year = 1987,
 abstract	= {The nonlinear model fitting problem is analyzed in this
		   paper, with special emphasis on the practical solution
		   techniques when the number of parameters in the model is
		   large. Classical approaches to small dimensional least
		   squares are reviewed and an extension of them to problems
		   involving many variables is proposed. This extension uses
		   the concept of partially separable structures, which has
		   already proved its applicability for large scale
		   optimization. An adaptable algorithm is discussed, which
		   chooses between various possible models of the objective
		   function. Preliminary numerical experience is also
		   presented, which shows that actual solution of a large
		   class of fitting problems involving several hundreds of
		   nonlinear parameters is possible at a reasonable cost.},
 summary	= {The nonlinear model fitting problem is analyzed, with
		   special emphasis on the practical solution techniques when
		   the number of parameters in the model is large. An
		   extension of classical approaches to problems involving
		   many variables is proposed, that uses the concept of
		   partially separable structures. An adaptable algorithm is
		   discussed, which chooses between various possible models of
		   the objective function. Preliminary numerical experience
		   shows that the solution of a large class of fitting
		   problems involving several hundreds of nonlinear parameters
		   is possible at a reasonable cost.}}

@article{Toin87d,
 author		= {Ph. L. Toint},
 title		= {{VE10AD}, a routine for large scale nonlinear least squares},
 journal	= {Harwell Subroutine Library},
 volume		= 2, year = 1987}

@article{Toin88,
 author		= {Ph. L. Toint},
 title		= {Global convergence of a class of trust region methods for
		   nonconvex minimization in {H}ilbert space},
 journal	= IMAJNA,
 volume		= 8, number = 2, pages = {231--252}, year = 1988,
 abstract	= {A class of trust-region methods for solving constrained
		   optimization problems in Hilbert space is described. The
		   algorithms of the class use, at every iteration, a local
		   model of the objective, on which very weak conditions are
		   imposed. Global convergence results are then derived for
		   the class without assuming convexity of the objective
		   functional. It is also shown that convergence of the
		   classical projected-gradient method can be viewed as a
		   special case of this theory. An example is finally given
		   that points out some difficulties appearing when using
		   active-set strategies in infinite-dimensional spaces.},
 summary	= {A trust-region method for solving constrained optimization
		   problems in Hilbert space is described. Global convergence
		   results are derived without assuming convexity of the
		   objective functional. It is also shown that convergence of
		   the classical projected-gradient method can be viewed as a
		   special case of this theory. An example is given that
		   points out some difficulties appearing when using
		   active-set strategies in infinite-dimensional spaces.}}

@techreport{Toin94d,
 author		= {Ph. L. Toint},
 title		= {A non-monotone trust-region algorithm for nonlinear
		   optimization subject to convex constraints: the complete
		   numerical results},
 institution	= FUNDP, address = FUNDP-ADDRESS,
 number		= {94/26}, year = 1994}
%abstract       = {The purpose of this paper is to detail the complete
%                  results of all test runs reported on in the companion
%                  paper \citebb{Toin96b}.},


@article{Toin96a,
 author		= {Ph. L. Toint},
 title		= {An assessment of non-monotone linesearch techniques for
		   unconstrained optimization},
 journal	= SISSC,
 volume		= 17, number = 3, pages = {725--739}, year = 1996}
%abstract       = {The purpose of this paper is to discuss the potential of
%                  nonmonotone techniques for enforcing convergence of
%                  unconstrained minimization algorithms from starting points
%                  distant from the solution. Linesearch-based algorithms are
%                  considered for both small and large problems, and
%                  extensive numerical experiments show that this potential
%                  is sometimes considerable. A new variant is introduced in
%                  order to limit some of the identified drawbacks of the
%                  existing techniques. This variant is again numerically
%                  tested and appears to be competitive. Finally, the impact
%                  of preconditioning on the considered methods is examined.},

@article{Toin96b,
 author		= {Ph. L. Toint},
 title		= {A non-monotone trust-region algorithm for nonlinear
		   optimization subject to convex constraints},
 journal	= MP,
 volume		= 77, number = 1, pages = {69--94}, year = 1997,
 abstract	= {This paper presents two new trust-region methods for
		   solving nonlinear optimization problems over convex
		   feasible domains. These methods are distinguished by the
		   fact that they do not enforce strict monotonicity of the
		   objective function values at successive iterates. The
		   algorithms are proved to be convergent to critical points
		   of the problem from any starting point. Extensive numerical
		   experiments show that this approach is competitive with the
		   {\sf LANCELOT} package.},
 summary	= {Two trust-region methods for nonlinear optimization over
		   convex feasible domains are presented. These methods are
		   distinguished by the fact that they do not enforce strict
		   monotonicity of the objective function values at successive
		   iterates. The algorithms are proved to be convergent to
		   critical points of the problem from any starting point.
		   Extensive numerical experiments show that this approach is
		   competitive with {\sf LANCELOT}.}}

@techreport{TongZhou99,
 author         = {X. Tong and S. Zhou},
 title          = {A trust-region algorithm for nonlinear inequality 
                   constrained optimization},
 institution    = {Department of Mathematics, Hunan University},
 address        = {Changsha, China},
 number         = {July}, year = 1999,
 abstract       = {This paper presents a new trust-region algorithm for 
                   nonlinear optimization subject to nonlinear
                   inequality constraints. An equivalent KKT condition
                   is derived, which is the base of constructing the new
                   algorithm. A global convergence of the algorithm to a
                   first-order KKT point is established under mild
                   conditions on the trial step, and a local quadratic
                   convergence theorem is proved for nondegenerate
                   minimizer point.},
 summary        = {A trust-region algorithm for 
                   nonlinear optimization subject to nonlinear
                   inequality constraints, based on an equivalent 
                   reformulations of the KKT conditions, is presented.
                   Global convergence of the algorithm to a
                   first-order KKT point is established under mild
                   conditions on the trial step, and a local Q-quadratic
                   convergence rate is attainable at a nondegenerate
                   minimizer.}}

@misc{Tsen98,
 author         = {P. Tseng},
 howpublished   = {(private communication)},
 month          = {September}, year = 1998}

@techreport{Tsen99,
 author         = {P. Tseng},
 title          = {A Convergent Infeasible Interior-Point Trust-Region Method 
                   for Constrained Optimization},
 institution    = {Department of Mathematics, University of Washington},
 address        = {Seattle, USA},
 month          = {May}, year = 1999,
 abstract       = {We study an infeasible interior-point trust-region method
                   for constrained optimization.  This method uses a 
                   logarithmic-barrier function for the slack variables and
                   updates the slack variables using a second-order correction.
                   We show that if a certain set containing the iterates is
                   bounded and the origin is not in the convex hull of the
                   nearly active constraint gradients everywhere on this set,
                   then any cluster point of the iterates is a 1st-order
                   stationary point.  If the cluster point satisfies an
                   additional assumption (which holds when the constraints
                   are linear or when the cluster point satisfies strict
                   complementarity and a local error bound holds), then it is
                   a 2nd-order stationary point.},
 summary        = {A primal interior-point method is presented for the 
                   inequality constrained nonlinear programming problem, 
                   that allows for infeasible points. The method uses a 
                   logarithmic barrier term for the slack variables and uses a 
                   trust-region to find a step.  The associated subproblem is 
                   solved exactly. Convergence to first-order critical points
                   is proved, as well as convergence to second-order ones under
                   additional assumptions.}}

@article{TsenYamaFuku96,
 author		= {P. Tseng and N. Yamashita and M. Fukushima},
 title		= {Equivalence of complemetarity problems to differentiable
		   minimization: a unified approach},
 journal	= SIOPT,
 volume		= 6, number = 2, pages = {446--460}, year = 1996}

@inproceedings{TsioMjol96,
 author         = {D. I. Tsioutsias and E. Mjolsness},
 title          = {A multiscale attentional framework for relaxation neural 
                   networks},
 booktitle      = {Advances in Neural Information Processing Systems.
                   Proceedings of the 1995 Conference}, 
 editor         = {D. S. Touretzky and M. C. Mozer and M. E. Hasselmo},
 publisher      = {MIT Press}, address = {Cambridge, MA, USA},
 volume         = 8, pages = {631--639}, year = 1996,
 abstract       = {We investigate the optimization of neural networks
                   governed by general objective functions. Practical
                   formulations of such objectives are notoriously
                   difficult to solve and a common problem is the poor
                   local extrema that result by any of the applied
                   methods. In this paper, a novel framework is
                   introduced for the solution of large-scale
                   optimization problems. It assumes little about the
                   objective function and can be applied to general
                   nonlinear, non-convex functions and objectives in
                   thousand of variables are thus efficiently minimized
                   by a combination of techniques-deterministic
                   annealing, multiscale optimization, attention
                   mechanisms and trust region optimization methods.},
 summary        = {The optimization of neural networks
                   governed by general objective functions is investigated. 
		   A novel framework is introduced for the solution of
		   large-scale such problems. It assumes little about the
                   objective function and can be applied to general
                   nonlinear, non-convex functions and objectives in
                   thousand of variables are thus efficiently minimized
                   by a combination of techniques-deterministic
                   annealing, multiscale optimization, attention
                   mechanisms and trust-region optimization methods.}}


@article{Tsuc93,
 author		= {T. Tsuchiya},
 title		= {Global convergence of the affine scaling algorithm for
		   primal degenerate strictly convex quadratic programming
		   problems},
 journal	= AOR,
 volume		= 47, pages = {509--539}, year = 1993}

@book{Turn39,
 author		= {H. W. Turnbull},
 title		= {Theory of Equations},
 publisher	= {Oliver and Boyd}, address = {Edinburgh and London},
 year		= 1939}

%%% U %%%

@techreport{Ulbr99,
 author		= {M. Ulbrich},
 title		= {Non-monotone Trust-Region Methods for Bound-Constrained
                   Semismooth Equations with Applications to Nonlinear Mixed
                   Complementarity Problems},
 institution    = {Faculty of Mathematics, Technische Universit\"{a}t 
                   M\"{u}nchen},
 number         = {TUM-M9906}, year = 1999,
 abstract       = {We develop and analyze a class of trust-region methods 
		   for bound-constrained semismooth systems of equations.  
		   The algorithm is based on a simply constrained 
		   differentiable minimization reformulation.  Our global
		   convergence results are developed in a very general
		   setting that allows for non-monotonicity of the function
		   values at subsequent iterates.  we propose a way of
		   computing trial steps by a semismooth Newton-like method
		   that is augmented by a projection onto the feasible set.
		   Under a Dennis-Mor\'{e}-type condition we prove that close
		   to a BD-regular solution the trust-region algorithm turns
		   into this projected Newton method, which is shown to
		   converge locally q-superlinearly or quadratically,
		   respectively, depending on the quality of the
		   approximate BD-subdifferentials used.  As an important
		   application we discuss in detail how the developed
		   algorithm can be used to solve nonlinear mixed
		   complementarity problems (MCPs). Hereby, the MCP is
		   converted into a bound-constrained semismooth equation
		   by means of an MCP function.  We propose and investigate
		   a new class of MCP-functions that are motivated by
		   affine-scaling techniques for nonlinear programming.
		   These functions have attractive theoretical properties
		   and prove to be efficient in practice.  This is
		   documented by our numerical results for a subset of
		   the MCPLIB problem collection.},
 summary	= {A class of trust-region methods for bound-constrained
		   semismooth systems of equations is developed, which is  
		   based on a simply constrained differentiable minimization
		   reformulation.  Global convergence results are proved
		   that allow for non-monotonicity of the function values
		   at successive iterates. Trial steps are computed by a
		   semismooth Newton-like method augmented by a projection
		   onto the feasible set. Under a suitable condition and close
		   to a regular solution, this technique turns into a projected
		   Newton method, which converges locally $Q$-superlinearly
		   or quadratically, depending on the quality of the
		   approximate subdifferentials used.  An application of this
		   method to the solution of nonlinear mixed complementarity
		   problems (MCPs) is then discussed, where the MCP is
		   converted into a bound-constrained semismooth equation by
		   means of an MCP function. A new class of MCP-functions is
		   introduced, that is motivated by affine-scaling techniques
		   for nonlinear programming. Numerical results for a subset of
		   the MCPLIB problem collection illustrate the efficiency of
		   this approach.}}

@techreport{UlbrUlbr97,
 author		= {M. Ulbrich and S. Ulbrich},
 title		= {Superlinear Convergence of Affine-scaling Interior-point
		   {N}ewton Methods for Infinite-dimensional Problems with
		   Pointwise Bounds.},
 institution	= CAAM, address = RICE-ADDRESS,
 number		= {TR97-05}, year = 1997,
 abstract	= {We develop and analyze a superlinearly convergent
		   affine-scaling interior-point Newton method for
		   infinite-dimensional problems with pointwise bounds in
		   $L^p$-space. The problem formulation is motivated by
		   optimal control problems with $L^p$-controls and pointwise
		   control constraints. The finite-dimensional convergence
		   theory by \citebb{ColeLi96b} makes essential use of the
		   equivalence of norms and the exact identifiability of the
		   active constraints close to an optimizer with strict
		   complementarity. Since these features are not available in
		   our infinite-dimensional framework, algorithmic changes are
		   necessary to ensure fast local convergence. The main
		   building block is a Newton-like iteration for an
		   affine-scaling formulation of the KKT-condition. We
		   demonstrate in an example that a stepsize rule to obtain an
		   interior iterate may require very small stepsizes even
		   arbitrarily close to a nondegenerate solution. Using a
		   pointwise projection instead we prove superlinear
		   convergence under a weak strict complementarity condition
		   and convergence with $Q-$rate $>1$ under a slightly
		   stronger condition if a smoothing step is available. We
		   discuss how the algorithm can be embedded in the class of
		   globally convergent trust-region interior-point methods
		   recently developed by \citebb{UlbrUlbrHein99}. Numerical
		   results for the control of a heating process confirm our
		   theoretical findings.},
 summary	= {A superlinearly convergent affine-scaling interior-point
		   Newton method for infinite-dimensional problems with
		   pointwise bounds in $L^p$-space is analysed. The problem
		   formulation is motivated by optimal control problems with
		   $L^p$-controls and pointwise control constraints.
		   Adaptations are made to the proposal by \citebb{ColeLi96b}
		   for the infinite-dimensional setting. The main building
		   block is a Newton-like iteration for an affine-scaling
		   formulation of the KKT-condition. Using a pointwise
		   projection, superlinear convergence under a weak strict
		   complementarity condition and convergence with $Q-$rate
		   $>1$ under a slightly stronger condition if a smoothing
		   step is available are established. It is shown how the
		   algorithm can be embedded in the class of globally
		   convergent trust-region interior-point methods of
		   \citebb{UlbrUlbrHein99}. Numerical results for
		   the control of a heating process confirm the theoretical
		   findings.}}

@misc{UlbrUlbr99,
 author		= {S. Ulbrich and M. Ulbrich},
 title          = {Nonmonotone Trust Region Methods for Nonlinear Equality
                   Constrained Optimization Without a Penalty Function},
 howpublished   = {Presentation at the First Workshop on Nonlinear
                   Optimization ``Interior-Point and Filter Methods'',
                   Coimbra, Portugal},
 year           = 1999,
 abstract       = {We propose and analyze a class of nonmonotone trust region
                   methods for nonlinear equality constrained optimization
                   problems.  The algorithmic framework yields a global 
                   convergence without using a merit function like the
                   augmented Lagrangian and allows nonmonotonicity
                   independently for both the constraint violation and the
                   objective function value.  Similar to the augmented
                   Lagrangian-based algorithm by \citebb{DennElAlMaci97},
                   each step is composed of a quasi-normal and a tangential
                   step.  Both steps are required to satisfy a fraction of
                   Cauchy decrease condition for their respective trust
                   region subproblems.  Our mechanism for accepting steps
                   combines nonmonotone decrease conditions on the constraint
                   violation and/or the objective function, which leads to a
                   flexibility and acceptance behaviour compared to
                   filter-based methods.  Preliminary numerical results for
                   the {\sf CUTE} test set confirm that our approach is very
                   promising.  The proposed class of algorithms can be extended
                   in a natural way to multilevel trust region algorithms.
                   Hereby, the constraints are grouped in blocks and for each
                   block a normal step is computed that acts tangential to
                   the previous blocks.  The generalization of our analysis
                   to this class of algorithms is making progress and we plan
                   to present convergence results also for this extended
                   framework.  The extension of our concept to general NLP
                   is under development.},
 summary        = {A class of non-monotone trust-region methods for nonlinear
                   equality constrained optimization problems is proposed,
                   where each step is composed of a quasi-normal and a 
                   tangential step.  Both steps are required to satisfy a
                   fraction of Cauchy decrease condition for their respective
                   trust-region subproblems and the mechanism for accepting
                   them combines non-monotone decrease conditions on the
                   constraint violation and/or the objective function. 
                   Preliminary numerical results show considerable promise.}}

@article{UlbrUlbrHein99,
 author		= {M. Ulbrich and S. Ulbrich and M. Heinkenschloss},
 title		= {Global convergence of trust-region interior-point
		   algorithms for infinite dimensional nonconvex minimization
		   subject to pointwise bounds},
 journal        = SICON,
 volume         = 37, number = 3, pages = {731--764}, year = 1999,
 abstract	= {A class of interior-point trust-region algorithms for
		   infinite-dimensional nonlinear optimization subject to
		   pointwise bounds in $L^p$-Banach spaces, $2 \leq p \leq
		   \infty$, is formulated and analyzed. The problem
		   formulation is motivated by optimal control problems, with
		   $L^p$-controled, and pointwise control constraints. The
		   interior-point trust-region algorithms are generalizations
		   of those recently introduced by \citebb{ColeLi96b} for
		   finite dimensional problems. Many of the generalizations
		   derived in this paper are also important in the finite
		   dimensional context. They lead to a better understanding of
		   the method and to considerable improvements in their
		   performance. All first- and second-order global convergence
		   results known for trust-region methods in the
		   finite-dimensional setting are extended to the
		   infinite-dimensional framework of this paper.},
 summary	= {Interior-point trust-region algorithms for
		   infinite-dimensional nonlinear optimization subject to
		   pointwise bounds in $L^p$-Banach spaces, $2 \leq p \leq
		   \infty$, are analyzed. The problem formulation is motivated
		   by optimal control problems, with $L^p$-controled, and
		   pointwise control constraints. The interior-point
		   trust-region algorithms are generalizations of those
		   introduced by \citebb{ColeLi96b} for finite-dimensional
		   problems. Many of the generalizations lead to a
		   better understanding of the methods and to considerable
		   improvements in their performance. All first- and
		   second-order global convergence results known 
		   in the finite-dimensional setting are
		   extended to the infinite-dimensional framework.}}

@article{UlbrUlbrVice00,
 author		= {M. Ulbrich and S. Ulbrich and L. Vicente},
 title          = {A globally convergent primal-dual interior point filter
                   method for nonconvex nonlinear programming},
 institution    = COIMBRA, address = COIMBRA-ADDRESS,
 number         = {TR00-11}, year = 2000,
 abstract       = {In this paper, the filter technique of \citebb{FletLeyf97}
                   is used to globalize the primal-dual interior-point
                   algorithm for nonlinear programming, avoiding the use of
                   merit functions and the updating of penalty parameters.
                   The new algorithm decomposes the primal-dual step obtained
                   from the perturbed first-order necessary conditions into a
                   normal and a tangential step, whose sizes are controlled by
                   a trust-region parameter.  Each entry in the filter is a
                   pair of coordinates: one resulting from feasibility and
                   centrality, and associated with the normal step; the other
                   resulting from optimality (complementarity and duality) and
                   related with the tangential step.  Global convergence to
                   first-order critical points is proved for the new
                   primal-dual interior-point filter algorithm.},
 summary        = {The filter technique of \citebb{FletLeyf97} is used to
                   globalize the primal-dual interior-point algorithm for
                   nonlinear programming.  The new algorithm decomposes the
                   primal-dual step obtained from the perturbed first-order
                   necessary conditions into a normal and a tangential step,
                   whose sizes are controlled by a trust-region parameter. 
                   Each entry in the filter is a pair of coordinates: one 
                   resulting from feasibility and centrality, and associated
                   with the normal step; the other resulting from optimality
                   (complementarity and duality) and related with the
                   tangential step.  Global convergence to first-order
                   critical points is proved for the new primal-dual
                   interior-point filter algorithm.}}

@techreport{UrbaTitsLawr98,
 author		= {T. Urban and A. L. Tits and C. L. Lawrence},
 title		= {A primal-dual interior-point method for nonconvex
		   optimization with multiple logarithmic barrier parameters
		   and with strong convergence properties},
 institution	= {Electrical Engineering and the Institute for Systems
		   Research, University of Maryland},
 address	= {College Park, USA},
 number		= {TR 98-27}, year = 1998,
 abstract	= {It is observed that an algorithm proposed in the 1980s for
		   the solution of nonconvex constrained optimization problems
		   is in fact a primal-dual logarithmic barrier interior-point
		   method closely related to methods under current
		   investigation in the research community. Its main
		   distinguishing features are judicious selection and update
		   of the multiple barrier parameters (one per constraint),
		   use of the objective function as merit function, and a
		   careful bending of the search direction. As a pay-off,
		   global convergence and fast local convergence ensue. The
		   purpose of the present note is to describe the algorithm in
		   the interior-point framework and language and to provide a
		   preliminary numerical evaluation. The latter shows that the
		   method compares well with algorithms recently proposed by
		   other research groups.},
 summary	= {An algorithm proposed in 1988 by Panier, Tits and
		   Herskovits for the solution of non-convex constrained
		   optimization problems is shown to be a primal-dual
		   logarithmic barrier interior-point method. Its
		   distinguishing features are multiple barrier parameters,
		   the use of the objective function as a merit function, and
		   the bending of the search direction. Global convergence and
		   fast local convergence ensue. The algorithm is described in
		   the interior-point framework and preliminary numerical
		   results are discussed.}}

%%% V %%%

@article{VandBoyd96,
 author		= {L. Vandenberghe and S. Boyd},
 title		= {Semidefinite programming},
 journal	= SIREV,
 volume		= 38, number = 1, pages = {49--95}, year = 1996}

@article{VandWhin69,
 author 	= {Van de Panne, C. and A. Whinston},
 title  	= {The symmetric formulation of the simplex method for
         	   quadratic programming},
 journal 	= {Econometrica},
 volume 	= 37, number = {}, pages = {507--527}, year = 1969}

@inproceedings{Vand85,
 author         = {J. S. Vandergraft},
 title          = {Efficient optimization methods for maximum likelihood 
                   parameter estimation},
 booktitle      = {Proceedings of the 24th IEEE Conference on Decision and 
                   Control},
 publisher      = {IEEE}, address = {New York, NY, USA}, 
 volume         = 3, pages = {1906--1909}, year = {1985},
 abstract       = {Recent research in numerical optimization has led to
                   development of efficient algorithms based on update
                   methods and model trust region techniques. The update
                   methods are a class of iterative schemes that avoid
                   expensive evaluations of (approximate) Hessians, yet
                   retain the rapid convergence properties of
                   Newton-like methods that require second-derivative
                   (Hessian) information. Model trust region techniques
                   avoid the costly step-length calculations that are
                   required by standard iterative methods based on
                   approximate Newton methods. The author describes the
                   most successful of the update methods and shows how
                   it, or more conventional methods such as scoring, can
                   be combined with a model trust region technique to
                   produce numerical algorithms that are ideally suited
                   to maximum-likelihood (ML) parameter
                   estimation. Specific properties of these algorithms
                   include a fast (superlinear) rate of convergence
                   together with the ability to handle parameter
                   constraints easily and efficiently.},
 summary        = {It is shown how the most successful of the
		   quasi-Newton methods and more conventional
		   methods such as scoring can be combined with
		   a trust-region technique to produce numerical
		   algorithms that are ideally suited to
		   maximum-likelihood parameter estimation. Specific
		   properties of these algorithms include a superlinear
		   rate of convergence and the ability to handle parameter
                   constraints easily and efficiently.}}


@book{VanHVand91,
 author		= {Van Huffel, S. and J. Vandewalle},
 title		= {The Total Least-Squares Problem: Computational Aspects and
		   Analysis},
 publisher	= SIAM, address = SIAM-ADDRESS,
 number		= 9, series = {Frontiers in Applied Nathematics}, year = 1991}

@techreport{Vand94,
 author  	= {R. J. Vanderbei},
 title   	= {{LOQO}: an interior point code for quadratic  programming},
 institution 	= {Program in Statistics and Operations,Research},
 address 	= {Princeton University, New Jersey, USA},
 type    	= {Technical Report}, number = {SOR 94-15}, year = 1994}

@techreport{VandShan97,
 author  	= {R. J. Vanderbei and D. F. Shanno},
 title   	= {An interior point algorithm for nonconvex nonlinear
		   programming},
 institution 	= {Program in Statistics and Operations Research},
 address 	= {Princeton University, New Jersey, USA},
 type    	= {Technical Report}, number = {SOR 97-21}, year = 1997}

@article{Vard85,
 author		= {A. Vardi},
 title		= {A trust region algorithm for equality constrained
		   minimization: convergence properties and implementation},
 journal	= SINUM,
 volume		= 22, number = 3, pages = {575--591}, year = 1985,
 abstract	= {In unconstrained minimization, trust region algorithms use
		   directions that are a combination of the quasi-Newton
		   direction and the steepest descent direction, depending on
		   the fit between the quadratic approximation of the function
		   and the function itself. Algorithms for nonlinear
		   constrained optimization problems usually determine a
		   quasi-Newton direction and use a line search technique to
		   determine the step. Since trust region strategies have
		   proved to be successful in unconstrained minimization, we
		   develop a new trust region strategy for equality
		   constrained minimization. This algorithm is analyzed and
		   global as well as local superlinear convergence theorems
		   are proved for various versions. We demonstrate how to
		   implement this algorithm in a numerically stable way. A
		   computer program based on this algorithm has performed very
		   satisfactorily on test problems; numerical results are
		   provided.},
 summary	= {A trust-region strategy for equality constrained
		   minimization is developed. This algorithm is analyzed and
		   global as well as local superlinear convergence theorems
		   are proved. It is demonstrated how to implement this
		   algorithm in a numerically stable way.}}

@article{Vard92,
 author		= {A. Vardi},
 title		= {New Minimax Algorithms},
 journal	= JOTA,
 volume		= 75, number = 3, pages = {613--634}, year = 1992,
 abstract       = {The purpose of this paper is to suggest a new, efficient
		   algorithm for the nonlinear minimax problem.  The problem
		   is transformed into an equivalent inequality-constraint
		   minimization problem. The algorithm has these features: an
		   active-set strategy with three types of constraints; the 
		   use of slack variables to handle inequality constraints;
		   and a trust-region strategy taking advantage of the
		   structure of the problem.  Following Tapia, this problem is
		   solved by an active set strategy which uses three types of 
		   active constraints (called here nonactive, semiactive and
		   active).  Active constraints are treated as equality
		   constraints and are assigned slack variables. This strategy
		   helps to prevent zigzagging. Numerical results are
		   provided.}, 
 summary        = {A algorithm for nonlinear min-max is described that
		   reformulates the min-max function as a set of inequality
		   constraints and uses an active-set and a trust-region
		   method that exploits the structure of the
		   problem. Numerical results are presented.}}

@book{Vava92,
 author		= {S. A. Vavasis},
 title		= {Nonlinear Optimization: Complexity Issues},
 publisher	= OUP, address = OUP-ADDRESS,
 series		= {International Series of Monographs on Computer Science},
 year		= 1992}

@article{Vava92b,
 author 	= {S. A. Vavasis},
 title  	= {Approximation algorithms for indefinite quadratic
		   programming},
 journal 	= MP,
 volume 	= 57, number = 2, pages = {279--311}, year = 1992}

@techreport{VavaZipp90,
 author		= {S. A. Vavasis and R. Zippel},
 title		= {Proving polynomial-time for sphere-constrained quadratic
		   programming},
 institution	= CS-CORNELL, address = CORNELL-ADDRESS,
 number		= {TR 90-1182}, year = 1990,
 abstract	= {Recently \citebb{Ye89} and Karmarkar have proposed similar
		   algorithms for minimizing a nonconvex quadratic function on
		   a sphere. These algorithms are based on trust-region work
		   going back to \citebb{Leve44} and \citebb{Marq63}. Although
		   both authors state that their algorithm is polynomial time,
		   neither makes estimates necessary to prove that conclusion
		   in a formal sense. In this report we derive estimates for
		   the convergence of the algorithm. Our estimates are based
		   on bounds for separation of roots of polynomials. These
		   bounds prove that the underlying decision problem is
		   polynomial time in the Turing machine sense.},
 summary	= {\citebb{Ye89} and Karmarkar have proposed similar
		   algorithms for minimizing a non-convex quadratic function on
		   a sphere. Estimates are derived for
		   the convergence of the algorithm, based on bounds for
		   separation of roots of polynomials. These bounds prove that
		   the underlying decision problem is polynomial time in the
		   Turing machine sense.}}

@phdthesis{Vice96,
 author		= {L. N. Vicente},
 title		= {Trust-region interior-point algorithms for a class of
		   nonlinear programming problems},
 school		= CAAM, address = RICE-ADDRESS,
 year		= 1995,
 note		= {Report TR96-05},
 abstract	= {This thesis introduces and analyzes a family of
		   trust-region interior-point (TRIP) reduced sequential
		   quadratic programming (SQP) algorithms for the solution of
		   minimization problems with nonlinear equality constraints
		   and simple bounds on some of the variables. These nonlinear
		   programming problems appear in applications in control,
		   design, parameter identification, and inversion. In
		   particular they often arise in the discretization of
		   optimal control problems. The TRIP reduced SQP algorithms
		   treat states and controls as independent variables. They
		   are designed to take advantage of the structure of the
		   problem. In particular they do not rely on matrix
		   factorizations of the linearized constraints, but use
		   solutions of the linearized state and adjoint equations.
		   These algorithms result from a successful combination of a
		   reduced SQP algorithm, a trust-region globalization, and a
		   primal-dual affine scaling interior-point method. The TRIP
		   reduced SQP algorithms have very strong theoretical
		   properties. It is shown in this thesis that they converge
		   globally to points satisfying first and second order
		   necessary optimality conditions, and in a neighborhood of a
		   local minimizer the rate of convergence is quadratic. Our
		   algorithms and convergence results reduce to those of
		   \citebb{ColeLi96b} for box-constrained optimization. An
		   inexact analysis is presented to provide a practical way of
		   controlling residuals of linear systems and directional
		   derivatives. Complementing this theory, numerical
		   experiments for two nonlinear optimal control problems are
		   included showing the robustness and effectiveness of these
		   algorithms. Another topic of this dissertation is a
		   specialized analysis of these algorithms for
		   equality-constrained optimization problems. The important
		   feature of the way this family of algorithms specializes
		   for these problems is that they do not require the
		   computation of normal components for the step and an
		   orthogonal basis for the null space of the Jacobian of the
		   equality constraints. An extension of \citebb{MoreSore83}'s
		   result for unconstrained optimization is presented, showing
		   global convergence for these algorithms to a point
		   satisfying the second-order necessary optimality conditions},
 summary	= {A family of trust-region interior-point (TRIP) reduced
		   sequential quadratic programming (SQP) algorithms, for the
		   solution of minimization problems with nonlinear equality
		   constraints and simple bounds, is introduced and analyzed.
		   These problems appear in control, design,
		   parameter identification, and inversion. In particular they
		   often arise in the discretization of optimal control
		   problems. The TRIP reduced SQP algorithms treat states and
		   controls as independent variables: they do not rely on
		   matrix factorizations of the linearized constraints, but
		   use solutions of the linearized state and adjoint
		   equations. These algorithms result from a combination of a
		   reduced SQP algorithm, a trust-region globalization, and a
		   primal-dual affine-scaling interior-point method. They
		   converge globally and quadratically to points satisfying
		   first and second order necessary optimality conditions. The
		   algorithms and convergence results reduce to those of
		   \citebb{ColeLi96b} for box-constrained optimization. An
		   inexact analysis is presented to provide a practical way of
		   controlling residuals of linear systems and directional
		   derivatives. Numerical experiments for two nonlinear
		   optimal control problems illustrate the robustness and
		   effectiveness of these algorithms. A specialized analysis
		   for equality-constrained problems shows that these
		   algorithms do not require the computation of normal
		   components for the step and an orthogonal basis for the
		   null space of the Jacobian of the equality constraints.}}

@article{Vice96b,
 author		= {L. N. Vicente},
 title		= {A comparison between line searches and trust regions for
		   nonlinear optimization},
 journal	= {Investiga\c{c}\~{a}o Operacional},
 volume		= 16, number = 2, pages = {173--179}, year = 1996,
 abstract	= {Line searches and trust regions are two techniques to
		   globalize nonlinear optimization algorithms. We claim that
		   the trust-region technique has built-in an appropriate
		   regularization of ill-conditioned second-order
		   approximation. The question we ask and then answer in this
		   short paper supports this claim. We force the trust-region
		   technique to act like a line search and we accomplish this
		   by always choosing the step along the quasi-Newton
		   direction. We obtain global convergence to a stationary
		   point as long as the condition number of the second-order
		   approximation is uniformly bounded, a condition that is
		   required in line searches but not in trust regions.},
 summary	= {It is claimed that the trust-region technique has built-in
		   an appropriate regularization of ill-conditioned
		   second-order approximation which is lacking in linesearch
		   methods. The trust-region technique is forced to act like a
		   linesearch by always choosing the step along the
		   quasi-Newton direction. Global convergence to a critical
		   point is obtained so long as the condition number of the
		   second-order approximation is uniformly bounded, a
		   condition required in linesearches but not in trust
		   regions.}}

@article{Voge90,
 author         = {C. R. Vogel},
 title          = {A constrained least squares regularization method for 
                   nonlinear ill-posed problems},
 journal        = SICON,
 volume         = 28, number = 1, pages = {34--49}, year = 1990,
 abstract       = {This paper deals with a method for solving ill-posed,
                   nonlinear Hilbert space operator equations
                   $F(x)=y$. Regularization is obtained by solving a
                   constrained least squares regularization problem min
                   $\|F(x)-y\|_2$ subject to $J(x) \leq beta_2$.
                   $\beta$ serves as a regularization parameter, and
                   $J(x)$ is a quadratic penalty functional. To robustly
                   and efficiently solve this regularization problem,
                   the author applies a trust region method. At each
                   iteration, the quadratic penalty constraint is
                   retained, a Gauss-Newton approximation to the
                   objective functional is taken, and he adds a
                   quadratic trust region constraint. The resulting
                   quadratic subproblem is then reformulated as a
                   nonlinear complementarity problem and solved using
                   Newton's method. He then applies methods to find
                   approximate solutions to a severely ill-posed
                   nonlinear first kind integral equation arising in
                   geophysics. The method of generalized cross
                   validation is used to pick the regularization
                   parameter when random error is present in the
                   discrete data.},
 summary        = {A trust-region method is applied for regularizing
		   ill-posed, nonlinear Hilbert space operator equations.
                   The subproblem is reformulated as a
                   nonlinear complementarity problem and solved using
                   Newton's method. The method of generalized cross
                   validation is used to pick the regularization
                   parameter when random error is present in the
                   discrete data.  The method is applied to find
                   approximate solutions to a severely ill-posed
                   nonlinear first kind integral equation arising in
                   geophysics.}}

%%% W %%%

@book{Wats80,
 author         = {G. A. Watson},
 title          = {Approximation Theory and Numerical Methods},
 publisher      = WILEY, address = WILEY-ADDRESS,
 year           = 1980}

@article{WatsBillMorg87,
 author		= {L. T. Watson and S. C. Billups and A. P. Morgan},
 title		= {{HOMPACK}: a suite of codes for globally convergent
		   homotopy algorithms},
 journal	= TOMS,
 volume		= 13, number = 3, pages = {281--310}, year = 1987}

@article{WatsKamReas85,
 author		= {L. T. Watson and M. P. Kamat and M. H. Reaser},
 title		= {A robust hybrid algorithm for computing multiple
		   equilibrium solutions},
 journal	= {Engineering Computations},
 volume		= 2, pages = {30--34}, year = 1985,
 abstract	= {A hybrid method is described that seeks to combine the
		   efficiency of a quasi-Newton method capable of locating
		   stable and unstable equilibrium configurations with a
		   robust homotopy method that is capable of tracking
		   equilibrium paths with turning points while exploiting
		   symmetry and sparsity of the Jacobian matrices. Numerical
		   results are presented for a shallow arch problem.},
 summary	= {A hybrid method is described that combines the efficiency
		   of a quasi-Newton method capable of locating stable and
		   unstable equilibrium configurations with a robust homotopy
		   method that is capable of tracking equilibrium paths with
		   turning points while exploiting symmetry and sparsity of
		   the Jacobian matrices. The quasi-Newton method uses a
		   double dogleg trust-region strategy. Numerical results are
		   presented for a shallow-arch problem.}}

@article{WeihCalzPana87,
 author		= {C. Weihs and G. Calzolari and L. Panattoni},
 title		= {The behavior of trust-region methods in {FIML}-estimation},
 journal	= {Computing},
 volume		= 38, number = 2, pages = {89--100}, year = 1987,
 abstract	= {This paper presents a Monte-Carlo study of the practical
		   reliability of numerical algorithms for FIML- estimation in
		   nonlinear econometric models. The performance of different
		   techniques of Hessian approximation in trust-region
		   algorithms is compared regarding their ``robustness''
		   against ``bad'' starting points and their ``global'' and
		   ``local'' convergence speed, i.e. the gain in the objective
		   function caused by individual iteration steps far off from
		   and near to the optimum. Concerning robustness and global
		   convergence speed, the crude GLS-type Hessian
		   approximations performed best, efficiently exploiting the
		   special structure of the likelihood function. But,
		   concerning local speed, general purpose techniques were
		   strongly superior. So, some appropriate mixture of these
		   two types of approximations turned out to be the only
		   techniques to be recommended.},
 summary	= {The reliability of numerical algorithms for FIML-estimation
		   in nonlinear econometric models is explored by a
		   Monte-Carlo study. Techniques of Hessian approximation in
		   trust-region algorithms are compared regarding their
		   robustness and their global and local convergence speed.
		   Concerning robustness and global convergence speed, the
		   crude GLS-type Hessian approximations performed best,
		   efficiently exploiting the special structure of the
		   likelihood function. Concerning local speed, general
		   purpose techniques were strongly superior. Some appropriate
		   mixture of these two types of approximations is
		   recommended.}}

@book{Wilk63,
 author		= {J. H. Wilkinson},
 title		= {Rounding Errors in Algebraic Processes},
 publisher	= {Her Majesty's Stationery Office}, address = {London},
 year		= 1963}

@book{Wilk65,
 author		= {J. H. Wilkinson},
 title		= {The Algebraic Eigenvalue Problem},
 publisher	= OUP, address = OUP-ADDRESS,
 year		= 1965}

@inproceedings{Wilk68,
 author		= {J. H. Wilkinson},
 title		= {A priori error analysis of algebraic processes},
 booktitle	= {Proceedings of the International Congress of Mathematicians},
 editor		= {I. G. Petrovsky},
 publisher	= {Mir Publishers}, address = {Moscow, USSR},
 pages		= {629--640}, year = 1968}

@article{Will64,
 author 	= {J. W. J. Williams},
 title  	= {Algorithm 232, {H}eapsort},
 journal 	= {Communications of the ACM},
 volume 	= 7, pages = {347--348}, year = 1964}

@techreport{Will90,
 author		= {K. A. Williamson},
 title		= {A Robust Trust Region Algorithm for Nonlinear Programming},
 institution	= CAAM, address = RICE-ADDRESS,
 number		= {TR90-22}, year = 1990,
 abstract	= {This work develops and tests a trust region algorithm for
		   the nonlinear equality constrained optimization problem.
		   Our goal is to develop a robust algorithm that can handle
		   lack of second-order sufficiency away from the solution in
		   a natural way. \citebb{CeliDennTapi85} give a trust region
		   algorithm for this problem, but in certain situations their
		   trust region subproblem is too difficult to solve. The
		   algorithm given here is based on the restriction of the
		   trust region subproblem given by \citebb{CeliDennTapi85} to
		   a relevant two dimensional subspace. This restriction
		   greatly facilitates the solution of the subproblem. The
		   trust region subproblem that is the focus of this work
		   requires the minimization of a possibly non-convex
		   quadratic subject to two quadratic constraints in two
		   dimensions. The solution of this problem requires the
		   determination of all the global solutions, and the
		   non-global solution, if it exists, to the standard
		   unconstrained trust region subproblem. Algorithms for
		   approximating a single global solution to the unconstrained
		   trust region subproblem have been well-established.
		   Analytical expressions for all of the solutions will be
		   derived for a number of special cases, and necessary and
		   sufficient conditions are given for the existence of a
		   non-global solution for the general case of the
		   two-dimensional unconstrained trust region subproblem.
		   Finally, numerical results are presented for a preliminary
		   implementation of the nonlinear programming algorithm, and
		   these results verify that it is indeed robust.},
 summary	= {A variant of the trust-region algorithm by
		   \citebb{CeliDennTapi85} for general nonlinear programming
		   is developed that uses a two-dimensional subproblem.  This
		   subproblem consists of globally minimizing a possibly
		   non-convex quadratic subject to two quadratic constraints
		   in two dimensions. A detailed study of this subproblem is
		   supplied for a number of special cases. Preliminary
		   numerical experiments illustrate the robustness of the
		   resulting algorithm.}} 

@phdthesis{Wils63,
 author		= {R. B. Wilson},
 title		= {A simplicial algorithm for concave programming},
 school		= {Harvard University}, address = {Massachusetts, USA},
 year		= 1963}

@phdthesis{Winf69,
 author		= {D. Winfield},
 title		= {Function and functional optimization by interpolation in
		   data tables},
 school		= {Harvard University}, address = {Cambridge, USA},
 year		= 1969}

@article{Winf73,
 author		= {D. Winfield},
 title		= {Function Minimization by Interpolation in a Data Table},
 journal	= JIMA,
 volume		= 12, pages = {339--347}, year = 1973,
 abstract	= {A method is described for unconstrained function
		   minimization using function values and no derivatives. A
		   quadratic model of the function is formed by interpolation
		   to points in a table of function values. The quadratic
		   model (not necessarily positive definite) is minimized over
		   a constraining region of validity to locate the next trial
		   point. The points of interpolation are chosen from a data
		   table containing function values at an initial grid and at
		   subsequent trial points. The method is efficient in its use
		   of function evaluations, but expensive in computation
		   required to choose new trial points.},
 summary	= {A method is described for unconstrained function
		   minimization using function values and no derivatives. A
		   quadratic model of the function is formed by interpolation
		   to points in a table of function values. The quadratic
		   model (not necessarily positive definite) is minimized over
		   a constraining region of validity to locate the next trial
		   point. The points of interpolation are chosen from a data
		   table containing function values at an initial grid and at
		   subsequent trial points. The method is efficient in its use
		   of function evaluations, but expensive in computation
		   required to choose new trial points.}}

@book{Wlok87,
 author		= {J. Wloka},
 title		= {Partial Differential Equations},
 publisher	= CUP, address = CUP-ADDRESS,
 year		= 1987}

@article{Wolf59,
 author 	= {P. Wolfe},
 title  	= {The {S}implex method for quadratic programming},
 journal 	= {Econometrica},
 volume 	= 27, pages = {382--398}, year = 1959}

@article{Wome82,
 author		= {R. S. Womersley},
 title		= {Optimality conditions for piecewise smooth functions},
 journal	= MPS,
 volume		= 17, pages = {13-27}, year = 1982}
 
@book{WonnWonn90,
 author		= {T. H. Wonnacott and R. J. Wonnacott},
 title		= {Introductory Statistics},
 publisher	= WILEY, address = WILEY-ADDRESS,
 edition	= {fifth}, year = 1990}

@phdthesis{Wrig76,
 author		= {M. H. Wright},
 title		= {Numerical methods for nonlinearly constrained optimization},
 school		= STANFORD, address = STANFORD-ADDRESS,
 year		= 1976}

@article{Wrig92,
 author		= {M. H. Wright},
 title		= {Interior methods for constrained optimization},
 journal	= {Acta Numerica},
 volume		= 1, pages = {341--407}, year = 1992}

@article{Wrig95,
 author		= {M. H. Wright},
 title		= {Why a pure primal {N}ewton barrier step may be infeasible},
 journal	= SIOPT,
 volume		= 5, number = 1, pages = {1--12}, year = 1995}

@inproceedings{Wrig98b,
 author		= {M. H. Wright},
 title          = {The interior-point revolution in constrained optimization},
 crossref       = {DeLeMurlPardTora98}, pages = {359--381}}

@article{Wrig99,
 author		= {M. H. Wright},
 title		= {Ill-conditioning and computational error in interior
		   methods for nonlinear programming},
 journal        = SIOPT,
 volume         = 9, number = 1, pages = {84--111}, year = 1999}

@article{WrigHolt85,
 author         = {S. J. Wright and J. N. Holt},
 title          = {Algorithms for nonlinear least squares with linear 
                   inequality constraints},
 journal        = SISSC,
 volume         = 6, number = 4, pages = {1033--1048}, year = 1985,
 abstract       = {Two algorithms for solving nonlinear least squares
                   problems with general linear inequality constraints
                   are described. At each step, the problem is reduced
                   to an unconstrained linear least squares problem in
                   the subspace defined by the active constraints, which
                   is solved using the Levenberg-Marquardt method. The
                   desirability of leaving an active constraint is
                   evaluated at each step, using a different technique
                   for each of the two algorithms. Each step is
                   constrained to be within a circular region of trust
                   about the current approximate minimiser, whose radius
                   is updated according to the quality of the step after
                   each iteration. Comparisons of the relative
                   performance of the two algorithms on small problems
                   and on a larger exponential data-fitting problem are
                   presented.},
 summary        = {Two algorithms for solving nonlinear least squares
                   problems with general linear inequality constraints
                   are described. At each step, the problem is reduced
                   to an unconstrained linear least squares problem in
                   the subspace defined by the active constraints, which
                   is solved using the Levenberg-Morrison-Marquardt method. The
                   desirability of leaving an active constraint is
                   evaluated at each step, using a different technique
                   for each of the two algorithms. Comparisons of the relative
                   performance of the two algorithms on small problems
                   and on a larger exponential data-fitting problem are
                   presented.}}

@article{Wrig87,
 author		= {S. J. Wright},
 title		= {Local properties of inexact methods for minimizing
		   nonsmooth composite functions},
 journal	= MP,
 volume		= 37, number = 2, pages = {232--252}, year = 1987}

@article{Wrig89,
 author		= {S. J. Wright},
 title		= {Convergence of {SQP}-like methods for constrained
		   optimization},
 journal	= SICON,
 volume		= 27, number = 1, pages = {13--26}, year = 1989}

@article{Wrig89b,
 author		= {S. J. Wright},
 title		= {An inexact algorithm for composite nondifferentiable
		   optimization},
 journal	= MP,
 volume		= 44, number = 2, pages = {221--234}, year = 1989,
 abstract	= {We describe an inexact version of \citebb{Flet87}'s $QL$
                   algorithm with second-order corrections for
                   minimizing composite nonsmooth functions. The method
                   is shown to retain the global and local convergence
                   properties of the original version, if the parameters
                   are chosen appropriately. It is shown how the inexact
                   method can be implemented for the case in which the
                   function to be minimized is an exact penalty function
                   arising from the standard nonlinear programming
                   problem. The method can also be applied to the
                   problems of nonlinear $\ell_1$- and $\ell_{\infty}$-
                   approximation.}, 
 summary        = {An inexact version of \citebb{Flet87}'s $QL$
                   algorithm with second-order corrections for
                   minimizing composite non-smooth functions, which
                   retains the global and local convergence properties
                   of the original version, is given.  It is shown how
                   the inexact method can be implemented for exact
                   penalty functions arising from nonlinear programming
                   problems, as well as problems of nonlinear $\ell_1$-
                   and $\ell_{\infty}$- approximation.}}

@article{Wrig90,
 author		= {S. J. Wright},
 title		= {Convergence of an inexact algorithm for composite nonsmooth
		   optimization},
 journal	= IMAJNA,
 volume		= 10, number = 3, pages = {299--321}, year = 1990,
 abstract	= {This paper describes an inexact version of \citebb{Flet82}'s
                   second-order correction algorithm for minimizing
                   composite nondifferentiable functions, and adds a
                   test which allows global convergence to be
                   demonstrated without the assumption that a global
                   minimum of the model function is found at each
                   iteration. Implementable criteria for accepting
                   inexact solutions of the subproblem, while retaining
                   local convergence properties, are also given.},
 summary	= {An inexact version of \citebb{Flet82}'s
                   second-order correction algorithm for minimizing
                   composite non-differentiable functions is described. A
                   test is suggested, which allows global convergence to be
                   proved without the assumption that a global
                   minimum of the model function is found at each
                   iteration. Implementable criteria for accepting
                   inexact solutions of the subproblem, while retaining
                   local convergence properties, are also given.}}

@book{Wrig97,
 author		= {S. J. Wright},
 title		= {Primal-Dual Interior-Point Methods},
 publisher	= SIAM, address = SIAM-ADDRESS,
 year		= 1997}

@techreport{Wrig98,
 author         = {S. J. Wright},
 title          = {Effects of finite-precision arithmetic on interior-point
                   methods for nonlinear programming},
 institution    = ANL, address = ANL-ADDRESS,
 number         = {MCS-P705-0198}, year = 1998}

@article{Wrig99b,
 author		= {S. J. Wright},
 title		= {Superlinear convergence of a stabilized {SQP} method to a
		   degenerate solution},
 journal        = COAP,
 volume         = 11, number = 3, pages = {253--275}, year = 1999}

@misc{WrigOrba99,
 author         = {S. J. Wright and D. Orban},
 title          = {Properties of the Log-Barrier Function for Degenerate
                   Nonlinear Programs},
 howpublished   = {Presentation at the First Workshop on Nonlinear
                   Optimization ``Interior-Point and Filter Methods'',
                   Coimbra, Portugal},
 year           = 1999}

@article{Wome85,
 author		= {R. S. Womersley},
 title		= {Local properties of algorithms for minimizing nonsmooth
		   composite functions},
 journal	= MP,
 volume		= 32, number = 1, pages = {69--89}, year = 1985}

%%% X %%%

@article{XiaoZhou92,
 author		= {Y. Xiao and F. Zhou},
 title		= {Nonmonotone Trust Region Methods with Curvilinear Path in
		   Unconstrained Optimization},
 journal	= {Computing},
 volume		= 48, number = {3--4}, pages = {303--317}, year = 1992,
 abstract	= {A general nonmonotone trust region method with curvilinear
		   path for unconstrained optimization problem is presented.
		   Although this method allows the sequence of objective
		   function values to be nonmonotone, convergence properties
		   similar to those of the usual trust region methods with
		   curvilinear path are proved under certain conditions. 
		   Some numerical results are reported which show the
		   superiority of the nonmonotone trust region method 
		   with respect to the numbers of gradient evaluations and
		   function evaluations.},
 summary	= {A non-monotone trust-region algorithm is proposed for
		   unconstrained optimization, whose convergence properties
		   are similar to those of the monotone versions. Numerical
		   experiments show the potential benefits of the approach.}}

@techreport{XiaoChu95,
 author		= {Y. Xiao and E. K. W. Chu},
 title		= {Nonmonotone Trust Region Methods},
 institution	= {Monash University}, address = {Clayton, Australia},
 number		= {95/17}, year = 1995,
 abstract	= {In this report, we study non-monotone techniques in trust
		   region methods for unconstrained minimization problems. Two
		   non-monotone trust region methods are developed and
		   assessed based on extensive numerical experiments with {\sf
		   CUTE}. Strategies for automatic selection and adjustment of
		   parameters are discussed, which enable switching between
		   non-monotone and monotone algorithms at different stages of
		   calculation according to the intermediate information
		   obtained. Numerical results show that these strategies
		   improve the efficiency and act as safeguards against the
		   possible inferior behavior of non-monotone algorithms. In
		   addition, the global convergence of the algorithms are
		   proved, and further modifications and possible improvements
		   are discussed.},
 summary	= {Two non-monotone trust-region methods are developed and
		   assessed based on extensive numerical experiments with {\sf
		   CUTE}. Strategies for automatic adjustment of parameters
		   are discussed, which enable switching between non-monotone
		   and monotone algorithms at different stages of calculation
		   according to the intermediate information obtained.
		   Numerical results show that these strategies improve the
		   efficiency of non-monotone algorithms. Global convergence
		   of the algorithms is proved, and further modifications
		   discussed.}}

@phdthesis{Xiao96,
 author		= {Y. Xiao},
 title		= {Non-monotone algorithms in optimization and their
		   applications},
 school		= {Monash University}, address = {Clayton, Australia},
 year		= 1996}

@article{XuZhan95,
 author         = {C. Xu and J. Zhang},
 title          = {An active set method for general $\ell_1$ linear problem 
                   subject to box constraints},
 journal        = {Optimization},
 volume         = 34, number = 1, pages = {67--80}, year = 1995,
 abstract       = {An active set algorithm is presented for the solution
                   of general $\ell_1$ linear problem with simple bound
                   constraints on variables. These problems appear as
                   subproblems when trust region type linear
                   approximation methods are used to minimize an
                   unconstrained nonsmooth composite function. The
                   method finds an optimal solution among dead points of
                   the problem and eventually terminates at an optimal
                   solution in a finite number of steps.},
 summary        = {An active set algorithm is presented for the solution
                   of general $\ell_1$ linear problem with simple bound
                   constraints on its variables.}}


@article{XuZhan99,
 author		= {C. Xu and J. Zhang},
 title		= {A Scaled Optimal Path Trust Region Algorithm},
 journal	= JOTA,
 volume		= 102, number = 1, year = 1999,
 abstract	= {Optimal path trust algorithm intends to determine a
		   trajectory along which the solution to a trust region
		   subproblem at a given point with any trust region radius is
		   located. Although its idea is attractive, the existing
		   optimal path method seems impractical because it requires,
		   in addition to a factorization, the calculation of full
		   eigensystem of the working matrix. We propose a scaled
		   optimal path trust region algorithm which finds a solution
		   of the subproblem in full dimensional space by just one
		   \citebb{BuncParl71} factorization for working matrix at
		   each iteration and by using the resulting unit lower
		   triangular factor to scale the variables in the problem. A
		   scaled optimal path can then be formed easily. The
		   algorithm has good convergence properties under commonly
		   used conditions. Computational results are presented to
		   show that this algorithm is robust and effective.},
 summary	= {A scaled optimal path trust-region algorithm is proposed,
		   which finds a solution of the subproblem in 
		   full-dimensional space by just one \citebb{BuncParl71}
		   factorization and by using the resulting
		   unit lower triangular factor to scale the variables.
		   The resulting algorithm has good convergence
		   properties. Computational results show that this algorithm
		   is robust and effective.}}

%%% Y %%%

@article{YabeYama97,
 author		= {H. Yabe and H. Yamashita},
 title		= {Q-superlinear Convergence of Primal-Dual Interior Point
		   Quasi-{N}ewton Methods for Constrained Optimization}, 
 journal	= {Journal of the Operations Research Society of Japan},
 volume		= 40, number = 3, pages = {415--436}, year = 1997}

@article{YamaFukuIbar89,
 author		= {E. Yamakawa and M. Fukushima and T. Ibaraki},
 title		= {An efficient trust region algorithm for minimizing
		   nondifferentiable composite functions},
 journal	= SISSC,
 volume		= 10, number = 3, pages = {562--580}, year = 1989,
 abstract	= {This paper presents a trust region method for solving the
		   following problem.  Minimize $\phi(x)=f(x)+c(x(x))$ over 
		   $x \in \Re^n$, where $f$ and $c$ are smooth functions and 
	           $h$ is a polyhedral convex function. Problems of this form
		   include various important applications such as min-max
		   optimization, Chebychev approximation and minimization of
		   exact penalty functions in nonlinear programming.  The 
		   algorithm is an adaptation of a recently proposed
		   successive quadratic programming method for nonlinear 
	      	   programming and makes use of second-order approximations
		   to both $f$ and $c$ in order to avoid the Maratos effect.
		   It is proved under appropriate assumptions that the
		   algorithm is globally and quadratically convergent to a 
		   solution of the problem.  Some numerical results
		   exhibiting the effectiveness of the algorithm are also
		   reported.}, 
 summary	= {A trust-region method for solving the problem of
		   minimizing $\phi(x)=f(x)+h(c(x))$ over 
		   $x \in \Re^n$, where $f$ and $c$ are smooth functions and 
	           $h$ is a polyhedral convex function. The 
		   algorithm is an adaptation of the SQP method by
 		   \citebb{Flet82b} and makes use of second-order approximations
		   to both $f$ and $c$ in order to avoid the Maratos effect.
		   Global and quadratic convergence is proved.
		   Numerical results illustrate the effectiveness of
		   the algorithm.}}}

@article{Yama82,
 author		= {H. Yamashita},
 title		= {A globally convergent constrained quasi-{N}ewton method
		   with an augmented {L}agrangian type penalty-function},
 journal	= MP,
 volume		= 23, number = 1, pages = {75--86}, year = 1982}

@techreport{YamaYabe96,
 author		= {H. Yamashita and H. Yabe},
 title		= {Nonmonotone {SQP} methods with global and superlinear
		   convergence properties},
 institution	= {Mathematical Systems, Inc.},
 address	= {Sinjuku-ku, Tokyo, Japan},
 year		= 1996}

@article{YamaYabe96b,
 author		= {H. Yamashita and H. Yabe},
 title          = {Superlinear and quadratic convergence of some primal-dual
                   interior point methods for constrained optimization},
 journal        = MPA,
 volume         = 75, number = 3, pages = {377--397}, year = 1996}

@techreport{YamaYabeTana97,
 author		= {H. Yamashita and H. Yabe and T. Tanabe},
 title		= {A Globally and superlineraly convergent primal-dual point
		   trust region method for large scale constrained
		   optimization},
 institution	= {Mathematical Systems, Inc.},
 address	= {Sinjuku-ku, Tokyo, Japan},
 year		= 1997,
 abstract	= {This paper proposes a primal-dual interior point method for
		   solving large scale nonlinearly constrained optimization
		   problems. To solve large scale problems, we use a trust
		   region method that uses second derivatives of functions for
		   minimizing the barrier-penalty function instead of the
		   usual line search strategies. By carefully controlling
		   parameters in the algorithm, superlinear convergence of the
		   iteration is also proved. A nonmonotone strategy is adopted
		   to avoid Maratos effect as in the nonmonotone SQP method of
		   \citebb{YamaYabe96}. The method is implemented and tested
		   with a variety of problems given by Hock and Schittkowski's
		   book and by {\sf CUTE}. The results of our numerical
		   experiment show that the given method is efficient for
		   solving large scale nonlinearly constrained optimization
		   problems.},
 summary	= {A primal-dual interior-point method is proposed, where the
		   barrier function is minimized by a trust-region method that
		   uses second derivatives. Superlinear convergence is proved.
		   A non-monotone strategy is adopted to avoid the Maratos
		   effect as in \citebb{YamaYabe96}. Results are reported for
		   a variety of problems given by Hock and Schittkowski and by
		   {\sf CUTE}. }}

@article{YamaFuku95,
 author		= {N. Yamashita and M. Fukushima},
 title		= {On Stationary Pointss of the Implicit {L}agrangian for
		   Nonlinear Complementarity Problems},
 journal	= JOTA,
 volume		= 84, number = 3, pages = {653--663}, year = 1995}

@techreport{YangLiZhou98,
 author         = {Y. Yang and  D. Li and S. Zhou},
 title          = {A trust region method for a semismooth reformulation to
                   variational inequality problems},
 institution	= {Department of Applied Mathematics, Hunan University},
 address        = {Changsha, China},
 number         = {May, 15},  year = 1998,
 abstract       = {We consider the variational inequality problem (denoted
                   by $VI(X,F)$): find an $x^* \in X$ such that 
                   $F(x^*)^T(x-x^*)\geq 0, \forall x \in X$, where
                   $F:\Re^n \rightarrow \Re^n$ is continuously differentiable
                   and the set $X$ has the following form 
                   $X:= \{x \in \Re^n \mid g(x) \geq 0, h(x) = 0 \}$ where
                   $g: \Re^n \rightarrow \Re^m$ and 
                   $h: \Re^n \rightarrow \Re^l$ are twice continuously
                   differentiable.  The KKT system of the above $VI(X,F)$ is
                   \[F(x)-g'(x)^Ty + h'(x)^Tz = 0,\]
                   \[ h(x) = 0,\ms g(x) \geq 0,\ms y \geq 0,\ms y^Tg(x) = 0.\]
                   In this paper, we present a well-defined trust region
                   method for solving this system based on its semismooth
                   reformulation.  The proposed method solves subproblems
                   inexactly.  We show that the proposed method converges
                   globally without monotone assumption on the function $F$.
                   Moreover, the rate of convergence is
                   Q-superlinear/Q-quadratic even if strict complementarity
                   does not hold at the solution.},
 summary        = {A trust region method is proposed for solving general
                   nonlinearly constrained variational inequality problems.
                   It is based on the semi-smooth reformulation of the
                   first-order optimality conditions, allows for inexact
                   solution of subproblems and is globally convergent even in
                   the non-monotone case. Its rate of convergence is
                   Q-superlinear or Q-quadratic even without strict
                   complementarity.}}

@article{YangToll91,
 author		= {E. K. Yang and J. W. Tolle},
 title		= {A class of methods for solving large, convex quadratic
		   programs subject to box constraints},
 journal	= MP,
 volume		= 51, number = 2, pages = {223--228}, year = 1991}

@article{YangZhanYou96,
 author		= {B. Yang and K. Zhang and Z. You},
 title		= {A successive quadratic programming method that uses new
		   corrections for search directions},
 journal	= JCM,
 volume		= 71, number = 1, pages = {15--31}, year = 1996}

@inproceedings{Ye89,
 author		= {Y. Ye},
 title		= {An extension of {K}amarkar's algorithm and the trust region
		   method for quadratic-programming},
 booktitle	= {Progress in Mathematical Programming},
 editor		= {N. Megiddo},
 publisher	= SPRINGER, address = SPRINGER-ADDRESS,
 pages		= {49--63}, year = 1989,
 abstract	= {An extension of \citebbs{Karm84} algorithm and the trust
		   region method is developed for solving quadratic
		   programming problems. This extension is based on the affine
		   scaling technique, followed by optimization over a trust
		   ellipsoidal region. It creates a sequence of interior
		   feasible points that converge to the optimal feasible
		   solution. The initial computational results reported here
		   suggest the potential usefulness of this algorithm in
		   practice.},
 summary	= {An extension of \citebbs{Karm84} algorithm and the
		   trust-region method is developed for solving quadratic
		   programming problems. It is based on the affine scaling
		   technique, followed by optimization over a trust
		   ellipsoidal region, and creates a sequence of interior
		   feasible points that converge to the optimal solution.
		   Computational results suggest its potential usefulness.}}

@article{YeTse89,
 author		= {Y. Ye and E. Tse},
 title		= {An extension of {K}armarkar's projective algorithm for
		   convex quadratic programming},
 journal	= MP,
 volume		= 44, number = 2, pages = {157--179}, year = 1989}

@article{Ye92,
 author		= {Y. Ye},
 title		= {On an affine scaling algorithm for nonconvex quadratic
		   programming},
 journal	= MP,
 volume		= 56, pages = {285--300}, year = 1992,
 abstract	= {We investigate the use of interior algorithms, especially
		   the affine-scaling algorithm, to solve 
                   nonconvex---indefinite or negative definite---quadratic 
                   programming
		   (QP) problems. Although the nonconvex QP with a polytope
		   constraint is a "hard" problem, we show that the problem
		   with an ellipsoidal constraint is "easy". When the "hard"
		   QP is solved by successively solving the "easy" QP, the
		   sequence of points monotonically converge to a feasible
		   point satisfying both the first and the second order
		   optimality conditions.},
 summary	= {The use of interior algorithms, especially the 
                   affine-scaling algorithm, to solve non-convex---indefinite or
		   negative definite---quadratic programming (QP) problems is
		   investigated. Although the non-convex QP with a polytope
		   constraint is a ``hard'' problem, it is shown that the
		   problem with an ellipsoidal constraint is ``easy''. When the
		   ``hard'' QP is solved by successively solving the "easy" QP,
		   the sequence of points monotonically converge to a feasible
		   point satisfying both the first and the second order
		   optimality conditions.}}

@techreport{Ye97,
 author		= {Y. Ye},
 title		= {Approximating quadratic programming with bound constraints},
 institution	= {Department of Management Sciences},
 address	= {The University of Iowa, USA},
 type		= {Working Paper}, year = 1997,
 abstract	= {We consider the problem of approximating the global maximum
		   of a quadratic program with $n$ variables subject to bound
		   constraints. Based on the results of Goemans and Williamson
		   (1996) and Nesterov (1997), we show that a $4/7$
		   approximate solution can be obtained in polynomial time},
 summary	= {The problem of approximating the global maximum of a
		   quadratic program with $n$ variables subject to bound
		   constraints is considered. Based on the results of Goemans
		   and Williamson (1996) and Nesterov (1997), it is shown that
		   a $4/7$ approximate solution can be obtained in polynomial
		   time.}}

@misc{YinHan98,
 author         = {H. Yin and J. Han},
 title          = {A new interior-point trust-region algorithm for nonlinear
                   minimization problems with simple bound constraints},
 howpublished	= {Presentation at the International Conference on Nonlinear
                   Programming and Variational Inequalities, Hong Kong},
 year           = 1998,
 abstract       = {In the paper, a new interior-point trust-region algorithm 
                   is given for nonlinear minimization problems with simple  
                   bound constraints.  The objective function of the quadratic
                   subproblem model is obtained based on the Newton step for
                   the first-order KKT condition of the problem, and the
                   constraints are a sphere trust-region constraints and a
                   system of bound constraints.  We accept or reject the trial
                   steps only depending on the objective function and its
                   approximation.  The global convergence to a KKT point is
                   obtained for our algorithm under some mild conditions. 
                   The second-order convergence is also hold under some
                   assumptions}, 
 summary        = {In the method of \citebb{ColeLi96b}, feasibility of the 
                   trial step is obtained by backtracking from a possibly
                   infeasible step into the interior of the feasible region.
                   A variant of this method is discussed, in which the initial
                   trial step is not allowed to be infeasible, therefore
                   avoiding the need of backtracking.}}

@book{Yosi70,
 author		= {K. Yosida},
 title		= {Functional Analysis},
 publisher	= SPRINGER, address = SPRINGER-ADDRESS,
 year		= 1970}

@techreport{Yuan83,
 author		= {Y. Yuan},
 title		= {Global convergence of trust region algorithms for nonsmooth
		   optimization},
 institution	= DAMTP, address = DAMTP-ADDRESS,
 number		= {DAMTP/NA13}, year = 1983,
 summary	= {See \citebb{Yuan85a}.}}

@article{Yuan84,
 author		= {Y. Yuan},
 title		= {An example of only linear convergence of trust region
		   algorithms for nonsmooth optimization},
 journal	= IMAJNA,
 volume		= 4, number = 3, pages = {327--335}, year = 1984,
 abstract	= {Most superlinear convergence results about trust-region
		   algorithms for non-smooth optimization are dependent on the
		   inactivity of trust region restrictions. An example is
		   constructed to show that it is possible that at every
		   iteration the trust region bound is active and the rate of
		   convergence is only linear, though strict complementarity
		   and second order sufficiency conditions are satisfied.},
 summary	= {An example is constructed where, at every iteration of a
		   trust-region method for non-smooth optimization the
		   trust-region bound is active and the rate of convergence is
		   only linear, though strict complementarity and second order
		   sufficiency conditions hold.}}

@article{Yuan85a,
 author		= {Y. Yuan},
 title		= {Conditions for convergence of trust region algorithms for
		   nonsmooth optimization},
 journal	= MP,
 volume		= 31, number = 2, pages = {220--228}, year = 1985,
 abstract	= {This paper discusses some properties of trust-region
		   algorithms for nonsmooth optimization. The problem is
		   expressed as the minimization of a function $h(f(x))$ where
		   $h(\cdot)$ is convex and where $f$ is a continuously
		   differentiable mapping from $\Re^n$ to $\Re^n$. Bounds for
		   the second order derivative approximation matrices are
		   discussed. It is shown that the results of \citebb{Powe75}
		   and \citebb{Powe84} hold for nonsmooth optimization.},
 summary	= {Properties of trust-region algorithms for non-smooth
		   optimization are discussed. The problem is expressed as the
		   minimization of a function $h(f(x))$ where $h(\cdot)$ is
		   convex and where $f$ is a continuously differentiable
		   mapping from $\Re^n$ to $\Re^n$. It is shown that the
		   results of \citebb{Powe75} and \citebb{Powe84} hold for
		   non-smooth optimization.}}

@article{Yuan85b,
 author		= {Y. Yuan},
 title		= {On the superlinear convergence of a trust region algorithm
		   for nonsmooth optimization},
 journal	= MP,
 volume		= 31, number = 3, pages = {269--285}, year = 1985,
 abstract	= {It is proved that the second-order correction trust-region
		   algorithm of \citebb{Flet82} ensures superlinear
		   convergence if some mild conditions are satisfied.},
 summary	= {It is proved that the second-order correction trust-region
		   algorithm of \citebb{Flet82} ensures superlinear
		   convergence if some mild conditions are satisfied.}}
                  
@article{Yuan90,
 author		= {Y. Yuan},
 title		= {On a Subproblem of Trust Region Algorithms for Constrained
		   Optimization},
 journal	= MP,
 volume		= 47, number = 1, pages = {53--63}, year = 1990,
 abstract	= {We study a subproblem that arises in some trust region
		   algorithms for equality constrained optimization. It is the
		   minimization of a general quadratic function with two
		   special quadratic constraints. Properties of such
		   subproblems are given. It is proved that the Hessian of the
		   Lagrangian has at most one negative eigenvalue, and an
		   example is presented to show that the Hessian may have a
		   negative eigenvalue when one constraint is inactive at the
		   solution.},
 summary	= {A subproblem that arises in some trust-region algorithms
		   for equality constrained optimization is studied. It is the
		   minimization of a general quadratic function with two
		   special quadratic constraints. Properties of such
		   subproblems are given. It is proved that the Hessian of the
		   Lagrangian has at most one negative eigenvalue, and an
		   example is presented to show that the Hessian may have a
		   negative eigenvalue when one constraint is inactive at the
		   solution.}}

@article{Yuan91,
 author		= {Y. Yuan},
 title          = {A dual algorithm for minimizing a quadratic function with
                   two quadratic constraints},
 journal        = {Journal of Computational Mathematics},
 volume         = 9, number = 4, pages = {348--359}, year = 1991,
 abstract       = {In this paper, we present a dual algorithm for minimizing
                   a convex quadratic function with two quadratic constraints.
                   Such a minimization problem is a subproblem that appears in
                   some trust region algorithms for general nonlinear
		   programming. Some theoretical properties of the dual
		   problem are given.  Global convergence of the algorithm
		   is proved and a local superlinear result is presented.
		   Numerical examples are also provided.},
 summary        = {A dual globally and superlinearly convergent algorithm is
		   proposed for  minimizing a convex quadratic objective
		   subject to two quadratic constraints. Numerical examples
		   are provided.}}

@inproceedings{Yuan93,
 author		= {Y. Yuan},
 title		= {A new trust-region algorithm for nonlinear optimization},
 booktitle	= {Proceedings of the First International Colloquium on
		   Numerical Analysis},
 editor		= {D. Bainov and V. Covachev},
 publisher	= {VSP}, address = {Zeist, The Netherlands},
 pages		= {141--152}, year = 1993,
 abstract	= {Trust region algorithms are a class of numerical algorithms
		   for optimization. In this paper we present a new trust
		   region algorithm for general nonlinear constrained
		   optimization problems. The algorithm is bases on the
		   $\ell_{\infty}$ exact penalty function. Under very mild
		   conditions, global convergence results for the algorithm
		   are given.},
 summary	= {Trust-region algorithms are a class of numerical algorithms
		   for optimization. A trust-region algorithm for general
		   nonlinear constrained optimization problems is presented.
		   The algorithm is bases on the $\ell_{\infty}$ exact penalty
		   function. Under very mild conditions, global convergence
		   results for the algorithm are given.}}

@inproceedings{Yuan94,
 author		= {Y. Yuan},
 title          = {Trust region algorithms for nonlinear programming},
 booktitle      = {Contemporary Mathematics},
 editor         = {Z. C. Shi},
 publisher      = AMS, address = AMS-ADDRESS,
 volume         = 163, pages = {205--225}, year = 1994,
 abstract       = {Nonlinear programming, or nonlinear optimization, is 
                   to minimize or maximize a nonlinear function, possibly 
                   subject to finitely many algebraic equations and 
                   inequalities. Trust region algorithms are a class of 
                   numerical algorithms for optimization. In this paper we 
                   review some main results of trust region algorithms for 
                   nonlinear optimization.},
 summary        = {A review of the many results in the domain of trust-region
                   methods for nonlinear optimization and the solution of
                   nonlinear systems of algebraic equations is presented.}}

@article{Yuan94b,
 author         = {Y. Yuan},
 title          = {On the convergence of trust region algorithms},
 journal        = {Mathematica Numerica Sinica},
 volume         = 16, number = 3, pages = {333-346}, year = 1994,
 abstract       = {Trust region algorithms for nonlinear optimization
                   and their convergence properties are
                   discussed. Convergence results and techniques for
                   convergence analysis are studied. An $A ( \delta , \eta)$ 
                   descent trial step is defined, and is used to
                   obtain a unified proof for global convergence of
                   trust region algorithms.},
 summary        = {Trust region algorithms for nonlinear optimization
                   and their convergence properties are discussed. An 
		   $A(\delta ,\eta)$ descent trial step is defined, and
		   is used to obtain a unified proof for global convergence
		   of such algorithms.},
 note		= {(in chinese)}}


@inproceedings{Yuan94c,
 author         = {Y. Yuan},
 title          = {Trust region algorithms for constrained optimization}, 
 booktitle      = {Proceedings of Conference on Scientific and Engineering
                   Computing for Young Chinese Scientists},
 editor         = {J.Z. Cui and Z.C. Shi and D.L. Wang},
 publisher      = {National Defence Industry Press}, address = {Beijing, China},
 pages          = {105--110}, year = 1994,
 abstract       = {In this paper, we review the trust region algorithms for
                   nonlinear optimization and the fundamental ideas of trust
                   region algorithms are discussed.  Model algorithms for
                   unconstrained optimization, constrained optimization, and
                   nonsmooth optimization are given.  Main techniques for
                   global convergence and local superlinear convergence are
                   analyzed.},
 summary        = {A survey of trust-region methods for nonlinear optimization
                   is given, with emphasis on global and locallys superlinear
                   convergence properties.}}

@inproceedings{Yuan94d,
 author         = {Y. Yuan},
 title          = {Nonlinear Programming: trust region algorithms}, 
 editor         = {S. T. Xiao and F. Wu},
 booktitle      = {Proceedings of Chinese SIAM annual meeting},
 publisher      = {Tsinghua University Press}, address= {Beijing, China},
 pages          = {83--97}, year = 1994,
 abstract       = {We review the main techniques used in trust region
                   algorithms for nonlinear constrained optimization},
 summary        = {A brief survey of trust-region methods for constrained
                   nonlinear optimization is presented.}}

@article{Yuan95,
 author		= {Y. Yuan},
 title		= {On the convergence of a new trust region algorithm},
 journal	= NUMMATH,
 volume		= 70, number = 4, pages = {515--539}, year = 1995,
 abstract	= {In this paper we present a new trust region algorithm for
		   general nonlinear constrained optimization problems. The
		   algorithm is based on the $L_{\infty}$ exact penalty
		   function. Under very mild conditions, global convergence
		   results for the algorithm are given. Local convergence
		   properties are also studied. It is shown that the penalty
		   parameter generated by the algorithm will be eventually not
		   less than the $l_1$ norm of the Lagrange multipliers at the
		   accumulation point. It is proved that the method is
		   equivalent to the sequential quadratic programming method
		   for all large $k$, hence superlinearly convergent results
		   of the SQP method can be applied. Numerical results are
		   also reported.},
 summary	= {A trust-region algorithm is presented for general nonlinear
		   constrained problems, based on the $L_{\infty}$ exact
		   penalty function. Under very mild conditions, global
		   and local convergence results for the algorithm are given. 
                   It is shown that
		   the penalty parameter generated by the algorithm will be
		   eventually not less than the $l_1$ norm of the Lagrange
		   multipliers at the accumulation point. It is proved that
		   the method is equivalent to the sequential quadratic
		   programming method for all large $k$, hence superlinearly
		   convergent results for the SQP method can be applied.
		   Numerical results are reported.}}

@article{Yuan96,
 author		= {Y. Yuan},
 title		= {A short note on the {D}uff-{N}ocedal-{R}eid algorithm},
 journal	= {SEA Bull. Math.},
 volume		= 20, number = 3, pages = {137--144}, year = 1996,
 abstract	= {In this short note, an example is given to show that the
		   algorithm of \citebb{DuffNoceReid87} for nonlinear
		   equations may converge to a non-optimal solution. It is
		   also shown that a slightly modification can ensure the
		   global convergence of the algorithm.},
 summary	= {An example is given to show that the algorithm of
		   \citebb{DuffNoceReid87} for nonlinear equations may
		   converge to a non-optimal solution. It is also shown that a
		   slightly modification can ensure the global convergence of
		   the algorithm.}}

@misc{Yuan97,
 author         = {Y. Yuan},
 title          = {Some properties of a trust region subproblem},
 howpublished   = {Presentation at the XVIth International Symposium on
                   Mathematical Programming, Lausanne},
 year		= 1997,
 summary        = {It is shown that the model reduction obtained by applying
		   the Steihaug-Toint algorithm on a convex quadratic model
                   in dimension two is at least half of that obtained by the
                   exact minimizer of the model within the trust region.}}

@article{Yuan98a,
 author		= {Y. Yuan},
 title		= {Trust region algorithms for nonlinear equations},
 journal        = {Information},
 volume         = 1, pages = {7--20}, year = 1998,
 abstract	= {In this paper, we consider the problem of solving nonlinear
		   equations $F(x)=0$, where $F(x)$ from $\Re^n$ to $\Re^m$ is
		   continuously differentiable. We study a class of general
		   trust region algorithms for solving nonlinear equations by
		   minimizing a given norm $\|F(x)\|$. The trust region
		   algorithm for nonlinear equations can be viewed as an
		   extension of the Levenberg-Marquardt algorithm for
		   nonlinear least squares. Global convergence of trust region
		   algorithms for nonlinear equations are studied and local
		   convergence analyses are also given.},
 summary	= {The problem of solving nonlinear equations $F(x)=0$, where
		   $F(x)$ from $\Re^n$ to $\Re^m$ is continuously
		   differentiable, is considered. We study a class of general
		   trust-region algorithms for solving nonlinear equations by
		   minimizing a given norm $\|F(x)\|$. The trust-region
		   algorithm for nonlinear equations can be viewed as an
		   extension of the Levenberg-Morrison-Marquardt algorithm for
		   nonlinear least-squares. Global convergence of trust-region
		   algorithms for nonlinear equations are studied and local
		   convergence analyses are also given.}}

@inproceedings{Yuan98b,
 author		= {Y. Yuan},
 title		= {An example of non-convergence of trust region algorithms},
 crossref	= {Yuan98}, pages = {205--218},
 abstract	= {It is well known that trust region algorithms have very
		   nice convergence properties. Trust region algorithms can be
		   classified into two kinds: one requires sufficient
		   reduction in objective function value (merit function
		   value, in the case of constrained optimization), the other
		   only needs reduction in objective function value. In
		   general, it can be shown that the algorithms that require
		   sufficient reductions have strong convergence result,
		   namely all accumulation points are stationary points. The
		   algorithms that do not require sufficient reductions have
		   the nice properties of accepting any better iterates, but
		   the convergence result is weak, only one accumulation point
		   is a stationary point. In this paper, we construct an
		   example to show that it can happen that for a class of
		   trust region algorithms that do not require sufficient
		   reductions the whole sequence need not to converge. In our
		   example, only one accumulation point is a stationary point
		   while all other accumulation points are non-stationary
		   points.},
 summary	= {An example is constructed which shows that it can happen
		   that for a class of trust-region algorithms that do not
		   require sufficient reductions the whole sequence need not
		   to converge. In the example, only one accumulation point is
		   a stationary point while all other accumulation points are
		   non-stationary.}}

@misc{Yuan98c,
 author		= {Y. Yuan},
 title		= {Optimality conditions for the {C}elis-{D}ennis-{T}apia
		   subproblems},
 howpublished	= {Presentation at the Optimization 98 Conference, Coimbra},
 year		= 1998,
 abstract	= {We give necessary and sufficient optimality conditions
		   which can be easily verified for local solutions of
		   Celis-Dennis-Tapia subproblem, which is a subproblem in
		   trust region algorithms for nonlinear constrained
		   optimization. If the CDT suproblem has no global solution
		   with the Hessian of Lagrangian positive semi-definite, the
		   Hessian at any local solution has at least negative
		   eigenvalue. Some other characters of local solutions are
		   also given. We also discuss the gap between necessary
		   conditions and sufficient conditions.},
 summary	= {Easily verifiable necessary and sufficient optimality
		   conditions are given for local solutions of the
		   Celis-Dennis-Tapia (CDT) subproblem, which is a subproblem
		   in trust-region algorithms for nonlinear constrained
		   optimization. If the CDT suproblem has no global solution
		   at with the Hessian of the Lagrangian is positive
		   semi-definite, the Hessian at any local solution has at
		   least one negative eigenvalue. Some other characteristics
		   of local solutions are also given. The gap between
		   necessary and sufficient conditions is also discussed.}}

@inproceedings{Yuan98d,
 author         = {Y. Yuan},
 title          = {Matrix computation problems in trust region algorithms
                   for optimization},
 booktitle      = {Proceedings of the 5th CSIAM annual meeting},
 editor         = {Q. C. Zeng and T. Q. Li and Z. S. Xue and Q. S. Cheng},
 publisher      = {Tsinghua University Press},
 address        = {Beijing, China},
 pages          = {54--64}, year = 1998,
 abstract       = {Trust region algorithms are a class of recently developed
                   algorithms for solving optimization problems.  The
                   subproblems appeared in trust region algorithms are
                   usually minimizing a quadratic function subject to one
                   or two quadratic constraints.  In this paper we review
                   some of the widely used trust region subproblems and some
                   matrix computation problems related to these trust region
                   subproblems.},
 summary        = {The linear algebra aspects of the solution methods for
                   various trust-region subproblems are reviewed.}}

@techreport{Yuan99,
 author		= {Y. Yuan},
 title          = {On the Truncated Conjugate-Gradient Method},
 institution    = ICMSEC, address = ICMSEC-ADDRESS,
 number         = {ICM-99-003}, year = 1999,
 abstract       = {In this paper, we consider the truncated conjugate-gradient
		   method for minimizing a convex quadratic function subject
		   to a ball trust region constraint.  It is showed that the
		   reduction in the objective function by the solution
		   obtained by the truncated CG method is at least half of the
		   reduction by the global minimizer in the trust region.},
 summary	= {It is shown that the model reduction obtained by applying
		   the Steihaug-Toint algorithm on a convex quadratic model is
		   at least half of that obtained by the exact minimizer of
		   the model within the trust region.}}

@techreport{Yuan99b,
 author         = {Y. Yuan},
 title          = {A review of trust region algorithms for optimization},
 institution    = ICMSEC, address = ICMSEC-ADDRESS,
 number         = {ICM-99-038}, year = 1999,
 abstract       = {Iterative methods for optimization can be classified
                   into two categories: line search methods and trust region
                   methods.  In this paper we give a review on trust region
                   algorithms for nonlinear optimization.  Trust region methods
                   are robust, and can be applied ti ill-conditioned problems.
                   A model trust region algorithm is presented to demonstrate
                   the trust region approaches.  Various trust region
                   subproblems and their properties are presented.
                   Convergence properties of trust region algorithms are given.
                   Techniques such as backtracking, non-monotone and
                   second-order correction are also briefly discussed.},
 summary        = {A survey of trust-region methods is presented, with special
                   emphasis on the possible subproblem solution techniques. 
                   Convergence properties for the unconstrained case are
                   reviewed and techniques such as backtracking, non-monotone
                   and second-order correction are also briefly discussed.}}

%%% Z %%%

@inproceedings{Zara71,
 author		= {E. H. Zarantonello},
 title		= {Projections on convex sets in {H}ilbert space and spectral
		   theory},
 booktitle	= {Contributions to Nonlinear Functional Analysis},
 editor		= {E. H. Zarantonello},
 publisher	= AP, address = AP-ADDRESS,
 pages		= {237--424}, year = 1971}

@article{Zhan89,
 author		= {J. Zhang},
 title		= {Superlinear convergence of a trust region-type successive
		   linear-programming method},
 journal	= JOTA,
 volume		= 61, number = 2, pages = {295--310}, year = 1989,
 abstract	= {The convergence rate of the SLP method suggested by
		   \citebb{ZhanKimLasd85} is discussed for composite
		   nondifferentiable optimization problems. A superlinear rate
		   is assured under a growth condition, and it is further
		   strengthened to a quadratic rate if the inside function is
		   twice differentiable. Several sufficient conditions are
		   given which make the growth condition true. The conditions
		   can be relaxed considerably in practical use.},
 summary	= {The convergence rate of the SLP method suggested by
		   \citebb{ZhanKimLasd85} is discussed for composite
		   non-differentiable optimization problems. A superlinear rate
		   is assured under a growth condition, and it is further
		   strengthened to a quadratic rate if the inside function is
		   twice differentiable. Several sufficient conditions are
		   given which make the growth condition true. The conditions
		   can be relaxed considerably in practical use.}}

@article{ZhanZhu90,
 author		= {J. Zhang and D. Zhu},
 title		= {Projected quasi-{N}ewton algorithm with trust-region for
		   constrained optimization},
 journal	= JOTA,
 volume		= 67, pages = {369--393}, year = 1990,
 abstract	= {\citebb{NoceOver85} proposed a two-sided projected Hessian
		   updating technique for equality constrained optimization
		   problems. Although local two-step Q-superlinear rate was
		   proved, its global convergence is not assured. In this
		   paper, we suggest a trust-region-type, two-sided, projected
		   quasi-Newton method, which preserves the local two-step
		   superlinear convergence of the original algorithm and also
		   ensures global convergence. The subproblem that we propose
		   is as simple as the one often used when solving
		   unconstrained optimization problems by trust-region
		   strategies and therefore is easy to implement.},
 summary	= {A trust-region-type, two-sided, projected quasi-Newton method
		   is proposed, which preserves the local two-step superlinear
		   convergence of the original algorithm of \citebb{NoceOver85}
                   and also ensures global convergence. The proposed subproblem
                   is as simple as the one used when solving unconstrained 
		   problems by trust-region strategies.}}

@article{ZhanZhu94,
 author         = {J. Zhang and D. Zhu},
 title          = {A projective quasi-{N}ewton method for nonlinear
                   optimization}, 
 journal        = JCAM,
 volume         = 53, number = 3, pages = {291-307}, year = 1994,
 abstract       = {A trust region method for nonlinear optimization
                   problems with equality constraints is proposed in
                   this paper. This method incorporates quadratic
                   subproblems in which orthogonal projective matrices
                   of the Jacobian of constraint functions are used to
                   replace QR decompositions. As QR decomposition does
                   not ensure continuity, but projective matrix does,
                   convergence behaviour of the new method can be
                   discussed under more reasonable assumptions. The
                   method maintains a two-step feature: one movement in
                   the range space of the Jacobian, whereas the other
                   one in the null space. It is proved that all
                   accumulation points of iterates are KKT
                   (Karush-Kuhn-Tucker) points and the method has a
                   one-step superlinear convergence rate.},
 summary        = {A trust region method for nonlinear optimization
                   problems with equality constraints is proposed
                   that incorporates quadratic subproblems in which orthogonal
		   projective matrices of the Jacobian of constraint functions
		   are used to replace QR decompositions. As QR decomposition
		   does not ensure continuity, but projective matrix does,
                   convergence behaviour of the new method is studied by
		   exploiting the continuity of these matrices. A
                   one-step superlinear convergence rate is also proved.}}


@article{ZhanZhu99,
 author         = {J. Zhang and D. Zhu},
 title		= {A nonmonotonic trust region method for constrained 
                   optimization problems},
 journal	= {Journal of the Australian Mathematical Society (Series B)},
 volume		= 40, number = 4, pages = {542--567}, year = 1999,
 abstract	= {In this paper we propose an easy-to-implement algorithm 
                   for solving general nonlinear optimization problems
                   with nonlinear equality constraints. A nonmonotonic
                   trust region strategy is suggested which does not
                   require the merit function to reduce its value in
                   every iteration. In order to deal with large
                   problems, a reduced Hessian is used to replace a full
                   Hessian matrix.  To avoid solving quadratic trust
                   region subproblems exactly which usually takes
                   substantial computation, we only require an
                   approximate solution which requires less
                   computation. The calculation of correction steps,
                   necessary from a theoretical view point to overcome
                   the Maratos effect but which often brings in negative
                   results in practice, is avoided in most cases by
                   setting a criterion to judge its necessity. Global
                   convergence and. a local superlinear rate are then
                   proved. This algorithm has a good performance. },
 summary	= {A nonmonotonic, reduced Hessian trust-region method is 
                   used to solve equality constrained nonlinear
                   optimization problems.  Approximate solutions to the
                   trust-region subproblems are allowed. Although theory
                   dictates that second-order correction steps be used
                   to overcome the Maratos effect, a suitable scheme is
                   developed to ensure that they are only used when
                   absolutely necessary. Global convergence at a local
                   superlinear rate is established, and the resulting
                   algorithm performs well in practice.}}
               
@article{ZhanZhuFan93,
 author		= {J. Zhang and D. Zhu and Y. Fan},
 title		= {A practical trust region method for equality constrained
		   optimization problems},
 journal	= OMS,
 volume		= 2, number = 1, pages = {45--68}, year = 1993,
 abstract	= {In this paper we propose an easy-to-implement algorithm for
		   solving general nonlinear optimization problems with
		   nonlinear equality constraints. In order to deal with large
		   scale problems, a reduced Hessian is used to replace the
		   full Hessian matrix. To avoid solving quadratic trust
		   region subproblems exactly, which usually takes most
		   computing time, we only require an approximate solution
		   with less computation. The calculation of correction steps,
		   that is necessary from the theoretical point of view to
		   overcome the \citebb{Mara78} effect but often brings in
		   negative results in practice, is avoided in most cases by
		   setting a criterion to judge its necessity. Global
		   convergence and a local superlinear rate are proved.
		   Numerical results are reported to show that this algorithm
		   has good performance.},
 summary	= {An easy-to-implement algorithm for solving general
		   nonlinear optimization problems with nonlinear equality
		   constraints is proposed, that uses a reduced Hessian matrix.
		   The quadratic trust-region subproblems are solved
                   approximately. The calculation of correction steps, that are
		   necessary from the theoretical point of view to overcome
		   the Maratos effect but prove costly in practice, is
		   avoided in most cases by a suitable test. Global 
                   and superlinear convergence are proved. Numerical results
                   are reported.}}

@article{ZhanKimLasd85,
 author		= {J. Zhang and N. H. Kim and L. S. Lasdon},
 title		= {An improved successive linear programming algorithm},
 journal	= {Management Science},
 volume		= 31, pages = {1312--1331}, year = 1985}

@article{ZhanXu99,
 author         = {J. Zhang and C. Xu},
 title          = {A Class of Indefinite Dogleg Path Methods for
                   Unconstrained Optimization},
 journal        = SIOPT,
 volume         = 9, number = 3, pages = {646--676}, year = 1999,
 abstract       = {In this paper we propose a convenient curvilinear search
		   method to solve the trust region subproblems arising from
		   unconstrained optimization problems.  The curvilinear paths
		   we set forth are dogleg paths, generated mainly by
		   employing Bunch-Parlett factorizations for general
		   symmetric matrices that may be indefinite.  This method is
		   easy to implement and globally convergent.  It is proved
		   that the method satisfies the first- and second-order
		   stationary point convergence properties and that the
		   convergence rate is quadratic under commonly used
		   conditions on functions. Numerical experiments are
		   conducted to compare this method with some existing
		   methods.},
 summary	= {A variant of the dogleg method for approximately solving
		   the trust-region subproblem is proposed.  This variant is
		   adequate for the case where the subproblem is non-convex.
		   In this case, it defines a family of path that use a
		   direction of negative curvature obtained from the
		   Bunch-Parlett factorization of the Hessian. Global 
		   convergence to unconstrained second-order stationary points
		   is proved for the resulting trust-region method, as well as
		   quadratic convergence of the associated version of Newton's
		   method.  Numerical results are shown.}} 

@article{ZhanXu99b,
 author         = {J. Zhang and C. Xu},
 title          = {Trust region dogleg path algorithms for unconstrained
		   minimization}, 
 journal	= AOR,
 volume		= 87, pages = {407--418}, year = 1999,
 abstract	= {In this paper, we propose a class of convenient curvilinear
		   search algorithms to solve trust region problems arising
		   from unconstrained optimization.  The curvilinear paths we
		   set are dogleg paths, generated mainly by employing the
		   Bunch-Parlett factorization for general symmetric matrices 
		   which may be indefinite.  These algorithms are easy to use
		   and globally convergent.  It is proved that these
		   algorithms satisfy the first- and second-order stationary
		   point convergence properties and that the rate of 
		   convergence is quadratic under commonly used assumptions},
 summary	= {Trust-region algorithms using curvilinear search
		   to approximately solve the possibly nonconvex subproblem
		   are proved to be globally convergent to first- and
		   second-order critical points.  The rate of convergence is
		   quadratic under typical assumptions.}} 

@article{ZhanXu99c,
 author         = {J. Zhang and C. Xu},
 title          = {A projected indefinite dogleg-path method for equality
                   constrained optimization},
 journal        = BIT,
 volume         = 39, number = 3, pages = {555-578}, year = 1999,
 abstract       = {In this paper, we propose a 2-step trust-region indefinite
                   dogleg path method for the solution of nonlinear equality 
                   constrained optimization problems.  The method is a globally
                   convergent Fontecilla method and an indefinite dogleg path
                   method is proposed to get approximate solutions of quadratic
                   programming subproblems even if the Hessian of the model
                   is indefinite. The dogleg path lie in the null space of
                   the Jacobian matrix of the constraints.  An $\ell_1$ exact
                   penalty function method is used in the method to determine
                   if a trial point is accepted.  The global convergence and
                   the local two-step superlinear convergence rate is proved.
                   Some numerical results are presented.},
 summary        = {A two-step trust-region algorithm is presented for the
                   solution of optimization problems with nonlinear equality
                   constraints.  The method is based on that of 
                   \citebb{Font90}, but uses an indefinite dogleg strategy in
                   the nullspace of the constraints Jacobian as a way to obtain
                   an approximate solution of the quadratic programming
                   subproblem. Global and locally two-step superlinear
                   convergence are proved and some numeruical experiements
                   shown.}}

@inproceedings{ZhanXuDu98,
 author		= {J. Zhang and C. Xu and L. Du},
 title		= {A more efficient variation of an indefinite dogleg path 
                   method},
 booktitle      = {Operations Research and its Applications. 
                   Third International Symposium, ISORA'98.},
 publisher      = {World Publishing Corp}, address = {Beijing, China}, 
 pages          = {428--434}, year = 1998,
 abstract	= {The authors previously suggested a class of indefinite 
                   dogleg path methods that can be used to find
                   approximate solutions of a trust region model in
                   which the working matrix is not necessary positive
                   definite. In this paper we propose a scaled version
                   of the indefinite dogleg path method. The main
                   advantage of the revision is that the scaled
                   subproblem has a 1 by 1 or 2 by 2 block diagonal matrix as
                   its working matrix so that the solution of the Newton
                   equation when the working matrix is positive definite
                   and the calculation of a direction of negative
                   curvature when the matrix is indefinite become much
                   easier. Also, it can save a substantial number of
                   matrix factorizations.},
 summary	= {A scaled version of the author's previous indefinite 
                   dogleg path method is considered. The main
                   advantage is that the scaled
                   subproblem has a 1 by 1 or 2 by 2 block diagonal Hessian,
                   so that the solution of the Newton
                   equations and directions of negative
                   curvature are simple to obtain.}}

@article{Zhan92,
 author		= {Y. Zhang},
 title		= {Computing a {C}elis-{D}ennis-{T}apia trust-region step for
		   equality constrained optimization},
 journal	= MP,
 volume		= 55, number = 1, pages = {109--124}, year = 1992,
 abstract	= {We study an approach for minimizing a convex quadratic
		   function subject to two quadratic constraints. This problem
		   stems from computing a trust-region step for an SQP
		   algorithm proposed by \citebb{CeliDennTapi85} for equality
		   constraint optimization. Our approach is to reformulate the
		   problem into a univariate nonlinear equation $\phi(\mu)=0$,
		   where the function $\phi(\mu)$ is continuous, at least
		   piecewise differentiable and monotone. Well-established
		   methods then can be readily applied. We also consider an
		   extension of our approach to a class of non-convex
		   quadratic functions and show that our approach is
		   applicable to reduced Hessian SQP algorithms. Numerical
		   results are presented indicating that our algorithm is
		   reliable, robust and has the potential to be used as a
		   building block to construct trust-region algorithms for
		   small-sized problems in constrained optimization.},
 summary	= {An approach to minimizing a convex quadratic function
		   subject to two quadratic constraints is studied. This
		   problem stems from computing a trust-region step for an SQP
		   algorithm proposed by \citebb{CeliDennTapi85} for equality
		   constraint optimization. The approach taken is to
		   reformulate the problem as a univariate nonlinear equation
		   $\phi(\mu)=0$, where the function $\phi(\mu)$ is
		   continuous, at least piecewise differentiable and monotone.
		   Well-established methods then can be readily applied. An
		   extension of this approach to a class of non-convex
		   quadratic functions is considered, and it is shown that the
		   approach is applicable to reduced Hessian SQP algorithms.
		   Numerical results are presented.}}
 
@article{Zhan94,
 author		= {Y. Zhang},
 title		= {On the convergence of infeasible interior-point methods for
		   the horizontal linear complementarity problem},
 journal	= SIOPT,
 volume		= 4, number = 1, pages = {208--227}, year = 1994}

@inproceedings{ZhaoWang93,
 author		= {M. Zhao and X. Wang},
 title		= {Model trust region technique in parallel {N}ewton method
		   for training neural networks},
 booktitle	= {IEEE International Symposium on Circuits and Systems (ISCAS
		   93)},
 publisher	= {IEEE}, address = {New York},
 volume         = 4, pages = {2399--2402}, year = 1993,
 abstract	= {In this article, the double dogleg trust region approach of
		   unconstrained minimization is introduced in the parallel
		   Newton's (PN) algorithm proposed in Zhao (1993). The PN
		   algorithm uses a recursive procedure for computing both the
		   Hessian matrix and the Newton direction. The input weights
		   of each neuron in the network are updated after each
		   presentation of the training data with a global strategy.
		   Experimental results indicate that the double dogleg trust
		   region approach is superior to the line search technique in
		   the PN algorithm, and that the PN algorithm with both
		   global strategies exhibits better convergence performance
		   than the well-known backpropagation algorithm.},
 summary	= {The double-dogleg trust-region approach of unconstrained
		   minimization is introduced into the parallel Newton's (PN)
		   algorithm, which uses a recursive procedure for
		   computing both the Hessian matrix and the Newton direction.
		   The input weights of each neuron in the network are updated
		   after each presentation of the training data with a global
		   strategy. Experimental results indicate that the
		   double-dogleg trust-region approach is superior to the
		   linesearch technique in the PN algorithm, and that the PN
		   algorithm with both global strategies exhibits better
		   convergence performance than backpropagation.}}

@inproceedings{ZhouSi98,
 author         = {G. Zhou and J. Si},
 title          = {Subset based training and pruning of sigmoid neural 
                   networks},
 booktitle      = {Proceedings of the 1998 American Control Conference,
                   Evanston, IL, USA}, 
 pages          = {58--62}, year = 1998,
 abstract       = {In the present paper we develop two algorithms,
                   subset based training (SBT) and subset based training
                   and pruning (SBTP), using the fact that the Jacobian
                   matrices in sigmoid network training problems are
                   usually rank deficient. The weight vectors are
                   divided into two parts during training, according to
                   the Jacobian rank sizes. Both SBT and SBTP are trust
                   region methods. Comparing to the standard
                   Levenberg-Marquardt (LM) method, these two algorithms
                   can achieve similar convergence properties as the LM
                   but with less memory requirements. Furthermore the
                   SBTP combines training and pruning of a network into
                   one comprehensive procedure. Some convergence
                   properties of the two algorithms are given to
                   qualitatively evaluate the performance of the
                   algorithms.},
 summary        = {Two trust-region algorithms,
                   subset based training (SBT) and subset based training
                   and pruning (SBTP), are developed using the fact that the
		   Jacobian matrices in sigmoid network training problems are
                   usually rank deficient. The weight vectors are
                   divided into two parts during training, according to
                   the Jacobian rank sizes. These two algorithms
                   have convergence properties similar to those of the
                   Levenberg-Morrison-Marquardt method but with less memory
		   requirements. Furthermore the SBTP combines training and
	           pruning of a network into one comprehensive procedure. }}

@article{ZhouSi98b,
 author         = {G. Zhou and J. Si},
 title          = {Advanced neural-network training algorithm with 
                   reduced complexity based on Jacobian deficiency},
 journal        = {IEEE Transactions on Neural Networks},
 volume         = 9, number = 3, pages = {448--453}, year = 1998,
 abstract       = {We introduce an advanced supervised training method
                   for neural networks. It is based on Jacobian rank
                   deficiency and it is formulated, in some sense, in
                   the spirit of the Gauss-Newton algorithm. The
                   Levenberg-Marquardt algorithm, as a modified
                   Gauss-Newton, has been used successfully in solving
                   nonlinear least squares problems including
                   neural-network training. It outperforms the basic
                   backpropagation and its variations with variable
                   learning rate significantly, but with higher
                   computation and memory complexities within each
                   iteration. The mew method developed in this paper is
                   aiming at improving convergence properties, while
                   reducing the memory and computation complexities in
                   supervised training of neural networks. Extensive
                   simulation results are provided to demonstrate the
                   superior performance of the new algorithm over the
                   Levenberg-Marquardt algorithm.},
 summary        = {A supervised training method for neural
		   networks based on Jacobian rank deficiency is formulated
		   in the spirit of the Gauss-Newton algorithm. The new
		   method aims at improving convergence properties compared
		   to the Levenberg-Morrison-Marquardt method, while 
                   reducing the memory and computation complexities in
                   supervised training of neural networks. Extensive
                   simulation results demonstrate the superior performance
		   of the new algorithm over the Levenberg-Morrison-Marquardt
		   algorithm.}}

@article{ZhouSi99,
 author		= {C. Zhou and J. Si},
 title		= {Subset-based training and pruning of sigmoid neural 
                   networks},
 journal	= {Neural Networks},
 volume		= 12, number = 1, pages = {79--89}, year = 1999,
 abstract	= {In the present paper we develop two algorithms, 
                   subset-based training (SBT) and subset-based training
                   and pruning (SBTP), using the fact that the Jacobian
                   matrices in sigmoid network training problems are
                   usually rank deficient. The weight vectors are
                   divided into two parts during training, according to
                   the Jacobian rank sizes. Both SBT and SBTP are
                   trust-region methods. Compared with the standard
                   Levenberg-Marquardt (LM) method, these two algorithms
                   can achieve similar convergence properties as the LM
                   but with fewer memory requirements. Furthermore the
                   SBTP combines training and pruning of a network into
                   one comprehensive procedure. The effectiveness of the
                   two algorithms is evaluated using three
                   examples. Comparisons are made with some existing
                   algorithms. Some convergence properties of the two
                   algorithms are given to qualitatively evaluate the
                   performance of the algorithms.},
 summary	= {Subset-based training (SBT) and subset-based training
                   and pruning (SBTP) trust-region algorithms are
                   developed to cope with the fact that the Jacobian
                   matrices in sigmoid network training problems are
                   usually rank deficient. Both methods prove to be as
                   effective as the Levenberg-Morrison-Marquardt
                   approach, but have significantly smaller memory
                   requirements.  Additionally SBTP combines training
                   and pruning of a network into one comprehensive
                   procedure. The effectiveness of the two algorithms is
                   evaluated using three examples. Comparisons are made
                   with existing algorithms, and convergence properties
                   are investigated.}}

@article{ZhouXiao94,
 author		= {F. Zhou and Y. Xiao},
 title		= {A Class of nonmonotone stabilization trust region methods},
 journal	= {Computing},
 volume		= 53, number = 2, pages = {119--136}, year = 1994,
 abstract	= {A class of trust region methods in unconstrained
		   optimization is presented, by adopting a nonmonotone
		   stabilization strategy. Under some regularity conditions,
		   the convergence properties of these methods are discussed.
		   Extensive numerical results which are reported show that
		   these methods are very efficient.},
 summary	= {A class of trust-region methods for unconstrained
		   optimization is presented which use a non-monotone
		   stabilization strategy. Under some regularity conditions,
		   the convergence properties of these methods are discussed.
		   Extensive numerical results which are reported.}}

@article{ZhouTits93,
 author		= {J. Zhou and A. L. Tits},
 title		= {Nonmonotone line search for minimax problems},
 journal	= JOTA,
 volume		= 76, number = 3, pages = {455--476}, year = 1993}

@article{Zhu92,
 author         = {D. Zhu},
 title          = {Convergence of a projected gradient method with trust 
                   region for nonlinear constrained optimization},
 journal        = {Optimization},
 volume         = 23, number = 3, pages = {215--235}, year = 1992,
 abstract       = {Describes a projected gradient algorithm with trust
                   region, introducing nondifferentiable merit function
                   for solving nonlinear constrained optimization
                   problems. The author shows that this method is
                   globally convergent even if conditions are weak. It
                   is also proved that, when the strict complementarity
                   condition holds, the proposed algorithm can be solved
                   by an equality constrained problem, allowing locally
                   rate of superlinear convergence.},
 summary        = {A globally convergent trust-region projected-gradient 
		   algorithm is described that uses a non-differentiable
		   merit function.}}

@article{Zhu95,
 author		= {D. Zhu},
 title		= {A Nonmonotonic Trust Region Technique for nonlinear
		   Constrained Optimization},
 journal	= JCM,
 volume		= 13, number = 1, pages = {20--31}, year = 1995,
 abstract	= {In this paper, a nonmonotonic trust region method for
		   optimization problems with equality constraints is proposed
		   by introducing a nonsmooth merit function and adopting a
		   correction step. It is proved that all accumulation points
		   of the iterates generated by the proposed algorithm are
		   Kuhn-Tucker points and that the algorithm is
		   q-superlinearly convergent.},
 summary	= {A non-monotonic method for problems with equality
		   constraints is proposed by introducing a non-smooth merit
		   function and a correction step. It is proved that all
		   accumulation points of the iterates generated are
		   Kuhn-Tucker points and that the algorithm is
		   Q-superlinearly convergent.}}

@techreport{Zhu99,
 author		= {D. Zhu},
 title          = {A Family of Generalized Projected Gradient Methods with
                   Mixing Strategy for Convex Constrained Optimization},
 institution    = {Department of Mathematics, Shanghai Normal University},
 address        = {Shanghai, China},
 number         = {(na)}, year = 1999,
 abstract       = {A family of generalized projected gradient algorithms is
                   proposed for convex constrained optimization problems.  
                   The mixed strategy in association with nonmonotone
                   technique is adopted in which projected gradient methods
                   switch to back tracking steps in trust region subproblems.
                   The globally convergent theoretical analysis of the proposed
                   algorithms are given and the local convergence rate of the
                   proposed algorithms are proved unders some reasonable
                   conditions},
 summary        = {A globally convergent trust-region method is proposed for
                   problems with convex constraints, that combines the
                   strategies of \citebb{ConnGoulSartToin93} with the
                   non-monotone technique of \citebb{DengXiaoZhou93}.}}

@article{Zhu96,
 author		= {C. Zhu},
 title		= {Asymptotic convergence analysis of some inexact proximal
		   point algorithms for minimization},
 journal	= SIOPT,
 volume		= 6, number = 3, pages = {626--637}, year = 1996}

@article{ZhuByrdLuNoce97,
 author		= {C. Zhu and R. H. Byrd and P. Lu and J. Nocedal},
 title		= {Algorithm 78: {L-BFGS-B}: Fortran subroutines for
		   large-scale bound constrained optimization},
 journal	= TOMS,
 volume		= 23, number = 4, pages = {550--560}, year = 1997}

@article{ZhuBrow87,
 author         = {T. Zhu and L. D. Brown},
 title          = {Two-dimensional velocity inversion and synthetic seismogram 
                   computation},
 journal        = {Geophysics},
 volume         = 52, number = 1, pages = {37--50}, year = 1987,
 abstract       = {A traveltime inversion schemes has been developed to
                   estimate velocity and interface geometries of
                   two-dimensional media from deep reflection data. The
                   velocity structure is represented by finite elements,
                   and the inversion is formulated as an iterative,
                   constrained, linear least-squares problems which can
                   be solved by either the singular value truncation
                   method or the Levenberg-Marquardt method. The damping
                   factor of the Levenberg-Marquardt method is chosen by
                   the model-trust region approach. The traveltimes and
                   derivative matrix required to solve the least-squares
                   problem are computed by ray tracing. To aid seismic
                   interpretation, the authors also include in the
                   inversion scheme a fast algorithm based on asymptotic
                   ray theory for calculating synthetic seismograms from
                   the derived velocity model.},
 summary        = {A trust-region method is used to 
                   estimate velocity and interface geometries of
                   two-dimensional media from deep-reflection data, where
		   the velocity structure is represented by finite elements.
                   The traveltimes and derivative matrix required to solve
		   the least-squares problem are computed by ray tracing.}}


@mastersthesis{Zupk97,
 author		= {M. Zupke},
 title		= {{T}rust-{R}egion-{V}erfahren zur {L}\"{o}sung nichtlinearer
		   {K}ompl\-em\-ent\-ar\-it\-\"{a}ts\-probleme},
 school		= HAMBURG, address = HAMBURG-ADDRESS,
 year		= 1997,
 summary	= {The nonlinear complementarity problem is reformulated as a
		   non-smooth system of equations by using a recently
		   introduced NCP-function. A trust-region-type method is then
		   applied to the resulting system of equations, that allows
		   an inexact solution of the trust-region subproblem. It is
		   shown that the algorithm is well-defined for a general
		   nonlinear complementarity problem and that it has some nice
		   global and local convergence properties. Numerical show the
		   advantage of using the non-monotone technique proposed by
		   \citebb{Toin96b}.}}


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% PROCEEDINGS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%


@proceedings{BachGrotKort83,
 editor		= {A. Bachem and M. Gr\"{o}tschel and B. Korte},
 title		= {Mathematical Programming: The State of the Art},
 booktitle	= {Mathematical Programming: The State of the Art},
 publisher	= SPRINGER, address = SPRINGER-ADDRESS,
 year		= 1983}

@proceedings{BalaThom84,
 editor		= {A. V. Balakrishnan and M. Thomas},
 title		= {11th IFIP Conference on System Modelling and Optimization},
 booktitle	= {11th IFIP Conference on System Modelling and Optimization},
 publisher	= SPRINGER, address = SPRINGER-ADDRESS,
 number		= 59,
 series		= {Lecture Notes in Control and Information Sciences},
 year		= 1984}

@proceedings{BoggByrdSchn85,
 editor		= {P. T. Boggs and R. H. Byrd and R. B. Schnabel},
 title		= {Numerical Optimization 1984},
 booktitle	= {Numerical Optimization 1984},
 publisher	= SIAM, address = SIAM-ADDRESS,
 year		= 1985}

@proceedings{ColeLi90,
 editor		= {T. F. Coleman and Y. Li},
 title		= {Large Scale Numerical Optimization},
 booktitle	= {Large Scale Numerical Optimization},
 publisher	= SIAM, address = SIAM-ADDRESS,
 year		= 1990}

@proceedings{CoxHamm90,
 editor    	= {M. G. Cox and S. J. Hammarling},
 title     	= {Reliable Scientific Computation},
 booktitle 	= {Reliable Scientific Computation},
 publisher 	= OUP, address = OUP-ADDRESS,
 year      	= 1990}

@proceedings{DeLeMurlPardTora98,
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