Results 91 to 100 of about 2,786 (218)

Comparison of Algebraic Multigrid Preconditioners for Solving Helmholtz Equations

Journal of Applied Mathematics, 2012
An algebraic multigrid (AMG) with aggregation technique to coarsen is applied to construct a better preconditioner for solving Helmholtz equations in this paper.
Dandan Chen, Ting-Zhu Huang, Liang Li
doaj   +1 more source

Image Deblurring with Krylov Subspace Methods

, 2011
Image deblurring, i.e., reconstruction of a sharper image from a blurred and noisy one, involves the solution of a large and very ill-conditioned system of linear equations, and regularization is needed in order to compute a stable solution.
Hansen, Per Christian
core  

Incorporating Krylov Subspace Methods in the ETDRK4 Scheme

, 2014
A modification of the (2,2)-Pade algorithm developed by Wade et al. for implementing the exponential time differencing fourth order Runge-Kutta (ETDRK4) method is introduced.
Allen, Jeffrey H.
core   +1 more source

Improving Efficiency of Rational Krylov Subspace Methods

, 2022
This thesis studies two classes of numerical linear algebra problems, approximating the product of a function of a matrix with a vector, and solving the linear eigenvalue problem $Av=\lambda Bv$ for a small number of eigenvalues.
Xu, Shengjie
core  

Preconditioned Dirichlet-Dirichlet Methods for Optimal Control of Elliptic PDE

Analele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2018
The discretization of optimal control of elliptic partial differential equations problems yields optimality conditions in the form of large sparse linear systems with block structure. Correspondingly, when the solution method is a Dirichlet-Dirichlet non-
Loghin Daniel
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Strategies For Recycling Krylov Subspace Methods and Bilinear Form Estimation

, 2017
The main theme of this work is effectiveness and efficiency of Krylov subspace methods and Krylov subspace recycling. While solving long, slowly changing sequences of large linear systems, such as the ones that arise in engineering, there are many issues
Swirydowicz, Katarzyna
core  

Improved New Block Preconditioner for Solving 3 × 3 Block Saddle Point Problems

Axioms
In order to overcome the computational challenges associated with block preconditioners for Krylov subspace methods, particularly those arising from Schur complement systems, this paper proposes an improved new block (INB) preconditioner for solving 3 ...
Xin-Hui Shao, Xin-Yang Liu
doaj   +1 more source

Multilevel acceleration of scattering-source iterations with application to electron transport

Nuclear Engineering and Technology, 2017
Acceleration/preconditioning strategies available in the SCEPTRE radiation transport code are described. A flexible transport synthetic acceleration (TSA) algorithm that uses a low-order discrete-ordinates (SN) or spherical-harmonics (PN) solve to ...
Clif Drumm, Wesley Fan
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Out-of-Core Krylov-Subspace Methods

, 1995
of operations in every iteration, namely multiplication of a vector by the matrix A, vector operations (additions and multiplication by scalars), and inner products.
Sivan Toledo
core  

Efficient Preconditioning Based on Scaled Tridiagonal and Toeplitz-like Splitting Iteration Method for Conservative Space Fractional Diffusion Equations

Mathematics
The purpose of this work is to study the efficient numerical solvers for time-dependent conservative space fractional diffusion equations. Specifically, for the discretized Toeplitz-like linear system, we aim to study efficient preconditioning based on a
Xiaofeng Guo
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