Generalized Barzilai and Borwein method for large-scale unconstrained optimization.

The focus of the thesis is on finding the unconstrained minimizer of a function by using the fixed steps gradient method. Specifically, we will focus on the Barzilai and Borwein (BB) method. In this thesis, we propose a generalized Barzilai and Borwein (GBB) method that can overcome some disadvantag...

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Main Author: Koo, Boon Yuan
Format: Thesis
Language:English
English
Published: 2011
Subjects:
Online Access:http://psasir.upm.edu.my/id/eprint/27372/
http://psasir.upm.edu.my/id/eprint/27372/1/FS%202011%20107R.pdf
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author Koo, Boon Yuan
author_facet Koo, Boon Yuan
author_sort Koo, Boon Yuan
building UPM Institutional Repository
collection Online Access
description The focus of the thesis is on finding the unconstrained minimizer of a function by using the fixed steps gradient method. Specifically, we will focus on the Barzilai and Borwein (BB) method. In this thesis, we propose a generalized Barzilai and Borwein (GBB) method that can overcome some disadvantages of the standard BB methods. The generalized Barzilai and Borwein method presented a special choice of steplength for the gradient method, which is a convex combination of two standard BB methods. Generally, the standard BB method does not guarantee a descent in the objective function at each iteration. We choose different scalar of combination between 0 and 1 to ensure that are descending in function value. This property is shown to be able to reduce the number of iteration in obtaining an approximate minimizer. The relationship between any gradient method and the shifted power method is considered. This relationship allows us to establish the convergence of the generalized Barzilai and Borwein method when applied to the problem of minimizing any strictly convex quadratic function. To highlight the performance of the generalized Barzilai and Borwein method, we applied them in solving the convex quadratic problem for the cases n = 2, 3, and 4. The results shown the number of iteration is decreasing for almost all cases. Finally, we concluded the achievements in our research and some future extensions are given at the end of thesis
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spelling upm-273722014-02-27T01:48:02Z http://psasir.upm.edu.my/id/eprint/27372/ Generalized Barzilai and Borwein method for large-scale unconstrained optimization. Koo, Boon Yuan The focus of the thesis is on finding the unconstrained minimizer of a function by using the fixed steps gradient method. Specifically, we will focus on the Barzilai and Borwein (BB) method. In this thesis, we propose a generalized Barzilai and Borwein (GBB) method that can overcome some disadvantages of the standard BB methods. The generalized Barzilai and Borwein method presented a special choice of steplength for the gradient method, which is a convex combination of two standard BB methods. Generally, the standard BB method does not guarantee a descent in the objective function at each iteration. We choose different scalar of combination between 0 and 1 to ensure that are descending in function value. This property is shown to be able to reduce the number of iteration in obtaining an approximate minimizer. The relationship between any gradient method and the shifted power method is considered. This relationship allows us to establish the convergence of the generalized Barzilai and Borwein method when applied to the problem of minimizing any strictly convex quadratic function. To highlight the performance of the generalized Barzilai and Borwein method, we applied them in solving the convex quadratic problem for the cases n = 2, 3, and 4. The results shown the number of iteration is decreasing for almost all cases. Finally, we concluded the achievements in our research and some future extensions are given at the end of thesis 2011-12 Thesis NonPeerReviewed application/pdf en http://psasir.upm.edu.my/id/eprint/27372/1/FS%202011%20107R.pdf Koo, Boon Yuan (2011) Generalized Barzilai and Borwein method for large-scale unconstrained optimization. Masters thesis, Universiti Putra Malaysia. Method of steepest descent (Numerical analysis) Differential equations, Elliptic - Numerical solutions Mathematical optimization English
spellingShingle Method of steepest descent (Numerical analysis)
Differential equations, Elliptic - Numerical solutions
Mathematical optimization
Koo, Boon Yuan
Generalized Barzilai and Borwein method for large-scale unconstrained optimization.
title Generalized Barzilai and Borwein method for large-scale unconstrained optimization.
title_full Generalized Barzilai and Borwein method for large-scale unconstrained optimization.
title_fullStr Generalized Barzilai and Borwein method for large-scale unconstrained optimization.
title_full_unstemmed Generalized Barzilai and Borwein method for large-scale unconstrained optimization.
title_short Generalized Barzilai and Borwein method for large-scale unconstrained optimization.
title_sort generalized barzilai and borwein method for large-scale unconstrained optimization.
topic Method of steepest descent (Numerical analysis)
Differential equations, Elliptic - Numerical solutions
Mathematical optimization
url http://psasir.upm.edu.my/id/eprint/27372/
http://psasir.upm.edu.my/id/eprint/27372/1/FS%202011%20107R.pdf