Full metadata record
DC FieldValueLanguage
dc.contributorDepartment of Applied Mathematicsen_US
dc.creatorTian, Boshi-
dc.publisherHong Kong Polytechnic University-
dc.rightsAll rights reserveden_US
dc.titleLower-order penalty methods for nonlinear optimization and complementarity problemsen_US
dcterms.abstractThe main purpose of this thesis is to propose efficient numerical methods to solve inequality constrained nonlinear programming problems and complementarity problems by virtue of the ℓ 1/p (p> 1)-penalty function. We propose an interior-point l1/p -penalty method for inequality constrained optimization problems by introducing a technique of the p-order relaxation to the nonconvex and non-Lipschitzian l1/p -penalty function and combining with an interior-point method. We introduce different kinds of constraint qualifications to establish first-order necessary conditions for the relaxed problem. We employ the modified Newton method to solve a sequence of logarithmic barrier subproblems and detail three reliable algorithms by using the Armijo line search. We prove that the iteration sequence generated by the proposed method converges to some KKT (or FJ) point of the original problem under mild conditions. Preliminary numerical experiments on small, medium and large test problems in the literature show that, comparing with some existing interior-point l1 -penalty methods, the proposed method is competitive in terms of the iteration numbers, better when comparing the number of updating the penalty parameters and more reliable when comparing the relative error. We introduce a box-constrained differentiable penalty method for nonlinear complementarity problems, which not only inherits the same convergence rate as the existing ℓ 1/p -penalty method but also overcomes its disadvantage of the non-Lipschitzianness. We introduce a concept of a uniform ξ-P-function with ξε[1, 2), under which we prove that the solution of box-constrained penalized equations converges to a solution of the original problem at an exponential order. Instead of solving the box-constrained penalized equations directly, we solve a corresponding differentiable least squares problem by using a trust-region Gauss-Newton method to design the globally convergent method that allows arbitrary starting points for solving the complementarity problems. Furthermore, we establish the connection between the local solution of the least squares problem and the solution of the original problem under mild conditions. We carry out the numerical experiments on the test problems from MCPLIB, which show that the proposed method is efficient and robust. We investigate an unconstrained differentiable penalty method for general complementarity problems without introducing artificial variables, which shares the exponential convergence rate under the assumption of a uniform ξ-P-function. Instead of solving the unconstrained penalized equations directly, we solve a corresponding differentiable least squares problem by using a trust-region Gauss-Newton method. Preliminary numerical experiments show that the proposed method is more robust than the box-constrained differentiable penalty method.en_US
dcterms.extentxiii, 126 pages : illustrations ; 30 cmen_US
dcterms.isPartOfPolyU Electronic Thesesen_US
dcterms.educationalLevelAll Doctorateen_US
dcterms.LCSHNonlinear programming -- Mathematical models.en_US
dcterms.LCSHMathematical optimization.en_US
dcterms.LCSHHong Kong Polytechnic University -- Dissertationsen_US
dcterms.accessRightsopen accessen_US

Files in This Item:
File Description SizeFormat 
b27629454.pdfFor All Users1.4 MBAdobe PDFView/Open

Copyright Undertaking

As a bona fide Library user, I declare that:

  1. I will abide by the rules and legal ordinances governing copyright regarding the use of the Database.
  2. I will use the Database for the purpose of my research or private study only and not for circulation or further reproduction or any other purpose.
  3. I agree to indemnify and hold the University harmless from and against any loss, damage, cost, liability or expenses arising from copyright infringement or unauthorized usage.

By downloading any item(s) listed above, you acknowledge that you have read and understood the copyright undertaking as stated above, and agree to be bound by all of its terms.

Show simple item record

Please use this identifier to cite or link to this item: https://theses.lib.polyu.edu.hk/handle/200/7747