Conjugate gradient methods with sufficient descent condition for large-scale unconstrained optimization

This thesis focuses on solving conjugate gradient methods for large-scale uncon- strained optimization problems. The main objective of this study is to propose some modifications to the standard conjugate gradient methods so that its search direction satisfies the sufficient descent and the bo...

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Main Author: Ling, Mei Mei
Format: Thesis
Language:English
Published: 2015
Subjects:
Online Access:http://psasir.upm.edu.my/id/eprint/85444/
http://psasir.upm.edu.my/id/eprint/85444/1/FS%202016%2091%20ir.pdf
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author Ling, Mei Mei
author_facet Ling, Mei Mei
author_sort Ling, Mei Mei
building UPM Institutional Repository
collection Online Access
description This thesis focuses on solving conjugate gradient methods for large-scale uncon- strained optimization problems. The main objective of this study is to propose some modifications to the standard conjugate gradient methods so that its search direction satisfies the sufficient descent and the boundedness condition. These two conditions appear to be a natural way of guaranteeing convergence for the conjugate gradient methods. We also propose some techniques for improving the conjugate gradient methods. The techniques in consideration include scaling parameters proposed by Oren and Luenberger, preconditioner suggested by Powell and memoryless symmetric rank one. In addition, the modified scaled conjugate gradient method is also implemented using nonmonotone line search. The convergence results for all of the modified conjugate gradient methods are also established. To validate the usefulness of our proposed improvement strategies, numerical ex- periments on a set of standard test problems were performed and presented. The results showed that our proposed methods can be good alternatives to the conju- gate gradient method in solving large-scale unconstrained optimization problems.
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institution Universiti Putra Malaysia
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language English
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publishDate 2015
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spelling upm-854442021-12-16T02:28:34Z http://psasir.upm.edu.my/id/eprint/85444/ Conjugate gradient methods with sufficient descent condition for large-scale unconstrained optimization Ling, Mei Mei This thesis focuses on solving conjugate gradient methods for large-scale uncon- strained optimization problems. The main objective of this study is to propose some modifications to the standard conjugate gradient methods so that its search direction satisfies the sufficient descent and the boundedness condition. These two conditions appear to be a natural way of guaranteeing convergence for the conjugate gradient methods. We also propose some techniques for improving the conjugate gradient methods. The techniques in consideration include scaling parameters proposed by Oren and Luenberger, preconditioner suggested by Powell and memoryless symmetric rank one. In addition, the modified scaled conjugate gradient method is also implemented using nonmonotone line search. The convergence results for all of the modified conjugate gradient methods are also established. To validate the usefulness of our proposed improvement strategies, numerical ex- periments on a set of standard test problems were performed and presented. The results showed that our proposed methods can be good alternatives to the conju- gate gradient method in solving large-scale unconstrained optimization problems. 2015-11 Thesis NonPeerReviewed text en http://psasir.upm.edu.my/id/eprint/85444/1/FS%202016%2091%20ir.pdf Ling, Mei Mei (2015) Conjugate gradient methods with sufficient descent condition for large-scale unconstrained optimization. Masters thesis, Universiti Putra Malaysia. Conjugate gradient methods
spellingShingle Conjugate gradient methods
Ling, Mei Mei
Conjugate gradient methods with sufficient descent condition for large-scale unconstrained optimization
title Conjugate gradient methods with sufficient descent condition for large-scale unconstrained optimization
title_full Conjugate gradient methods with sufficient descent condition for large-scale unconstrained optimization
title_fullStr Conjugate gradient methods with sufficient descent condition for large-scale unconstrained optimization
title_full_unstemmed Conjugate gradient methods with sufficient descent condition for large-scale unconstrained optimization
title_short Conjugate gradient methods with sufficient descent condition for large-scale unconstrained optimization
title_sort conjugate gradient methods with sufficient descent condition for large-scale unconstrained optimization
topic Conjugate gradient methods
url http://psasir.upm.edu.my/id/eprint/85444/
http://psasir.upm.edu.my/id/eprint/85444/1/FS%202016%2091%20ir.pdf