Results 31 to 40 of about 217 (109)

A Sharpened Condition Number Estimate for the BPX Preconditioner of Elliptic Finite Element Problems on Highly Nonuniform Triangulations.

, 1991
In this paper it is shown that for highly nonuniformly refined triangulations the condition number of the BPX preconditioner for elliptic finite element problems grows at most linearly in the depth of refinement.
Bornemann, Folkmar A.
core   +1 more source

Algorithm and linear convergence of the H-spectral radius of weakly irreducible quasi-positive tensors

Open Mathematics
A class of weakly irreducible quasi-positive tensors is defined by using directed hypergraphs of tensors, which generalizes the essential positive tensors, weakly positive tensors, generalized weakly positive tensors, and weakly essential irreducible ...
Lv Hongbin, Chen Meixiang
doaj   +1 more source

Preconditioning Indefinite Discretization Matrices.

, 1987
The finite element discretization of many elliptic boundary value problems leads to linear systems with positive definite and symmetric coefficient matrices. Many efficient preconditioners are known for these systems.
Yserentant, Harry
core   +1 more source

An inverse LU preconditioner based on the Sherman–Morrison formula

Analele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica
An approximate inverse LU preconditioner is constructed based on the Sherman–Morrison formula. Applying recursively that inversion formula a multiplicative decomposition of the inverse of a matrix is obtained.
Bru R., Cerdán J., Marín J., Mas J.
doaj   +1 more source

TOBLER: An error analysis of Galerkin projection methods for linear systems with tensor product structure

, 2020
Recent results on the convergence of a Galerkin projection method for the Sylvester equation are extended to more general linear systems with tensor product structure.
Christine Tobler, Bernhard Beckermann, Daniel Kressner   +2 more
core  

Schwarz Methods: To Symmetrize Or Not To Symmetrize

, 1997
. A preconditioning theory is presented which establishes sufficient conditions for multiplicative and additive Schwarz algorithms to yield self-adjoint positive definite preconditioners.
Stefan Vandewalle, Michael Holst, Vandewalle, Stefan, Holst, M.   +3 more
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How to Best Choose the Outer Coarse Mesh in the Domain Decomposition Method of Bank and Jimack. [PDF]

Vietnam J Math, 2022
Ciaramella G, Gander MJ, Mamooler P.
europepmc   +1 more source

INTERVAL ITERATIVE METHODS FOR COMPUTING MOORE-PENROSE INVERSE ∗

, 2008
In this paper, we import interval method to the iteration for computing Moore-Penrose inverse of the full row (or column) rank matrix. Through modifying the classical Newton iteration by interval method, we can get better numerical results.
Xian Zhang, Yimin Wei, Jianfeng Cai
core  

A Method for Constructing Diagonally Dominant Preconditioners based on Jacobi Rotations

, 2008
A method is presented to make a given matrix strictly diagonally dominant as much as possible based on Jacobi rotations in this paper. The strictly diagonally dominant rows are used to build a precon-ditioner for some iterative method.
Yuan Plamen, Jin Yun, Y. Yalamov
core  

An Adaptive Multilevel Approach to Parabolic Equations III.

, 1991
Part III of the paper is devoted to the construction of an adaptive FEM solver in two spatial dimensions, which is able to handle the singularly perturbed elliptic problems arising from discretization in time.
Bornemann, Folkmar A.
core   +1 more source