Results 31 to 40 of about 888,833 (294)

Differentiating the Method of Conjugate Gradients [PDF]

open access: yesSIAM Journal on Matrix Analysis and Applications, 2014
The method of conjugate gradients (CG) is widely used for the iterative solution of large sparse systems of equations $Ax=b$, where $A\in\Re^{n\times n}$ is symmetric positive definite. Let $x_k$ denote the $k$th iterate of CG. This is a nonlinear differentiable function of $b$. In this paper we obtain expressions for $J_k$, the Jacobian matrix of $x_k$
Serge Gratton   +3 more
openaire   +2 more sources

Reducing Impulse Noise in Images Using an Improved Formula Conjugate Gradient Method

open access: yesZanco Journal of Pure and Applied Sciences
The conjugate formula's significance is frequently emphasised by conjugate gradient approaches. In this paper, a novel conjugate coefficient for the conjugate gradient technique is introduced using a quadratic model and conjugacy condition.
Basim A. Hassan, Yousif Ali Mohammed
doaj   +1 more source

Two modified hybrid conjugate gradient methods based on a hybrid secant equation

open access: yesMathematical Modelling and Analysis, 2013
Taking advantage of the attractive features of Hestenes–Stiefel and Dai–Yuan conjugate gradient methods, we suggest two globally convergent hybridizations of these methods following Andrei's approach of hybridizing the conjugate gradient parameters ...
Saman Babaie-Kafaki, Nezam Mahdavi-Amiri
doaj   +1 more source

Flexible Conjugate Gradients

open access: yesSIAM Journal on Scientific Computing, 2000
The author discusses the conjugate gradient method for the numerical solution of a linear large sparse system, using preconditioning technique. To maintain the optimal convergence properties of the method, the author considers a variant of the conjugate gradient method (called flexible conjugate gradient) that performs an explicit orthogonalization of ...
openaire   +4 more sources

Nonlinear conjugate gradient methods [PDF]

open access: yes, 2014
summary:Modifications of nonlinear conjugate gradient method are described and ...
Lukšan, Ladislav, Vlček, Jan
core   +1 more source

Two efficient modifications of AZPRP conjugate gradient method with sufficient descent property

open access: yesJournal of Inequalities and Applications, 2022
The conjugate gradient method can be applied in many fields, such as neural networks, image restoration, machine learning, deep learning, and many others.
Zabidin Salleh   +2 more
doaj   +1 more source

Computing several eigenpairs of Hermitian problems by conjugate gradient iterations

open access: yes, 2008
The paper is concerned with algorithms for computing several extreme eigenpairs of Hermitian problems based on the conjugate gradient method. We analyse computational strategies employed by various algorithms of this kind reported in the literature and ...
Ovtchinnikov, E.
core   +1 more source

Algorithm for Scaling Variables in Minimization Methods

open access: yesAlgorithms
Eliminating poor scaling of variables of minimized functions is a pressing issue in solving high-dimensional minimization problems where it is impossible to use methods that change the metric of the space with full-scale metric matrices.
Elena Tovbis   +2 more
doaj   +1 more source

Two New Conjugate Gradient Methods for Unconstrained Optimization

open access: yesComplexity, 2020
The conjugate gradient method is very effective in solving large-scale unconstrained optimal problems. In this paper, on the basis of the conjugate parameter of the conjugate descent (CD) method and the second inequality in the strong Wolfe line search ...
Meixing Liu, Guodong Ma, Jianghua Yin
doaj   +1 more source

Nonlinear Conjugate Gradient Methods with Wolfe Type Line Search

open access: yesAbstract and Applied Analysis, 2013
Nonlinear conjugate gradient method is one of the useful methods for unconstrained optimization problems. In this paper, we consider three kinds of nonlinear conjugate gradient methods with Wolfe type line search for unstrained optimization problems ...
Yuan-Yuan Chen, Shou-Qiang Du
doaj   +1 more source

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