Results 51 to 60 of about 5,336 (304)

A Modified SSOR Preconditioning Strategy for Helmholtz Equations

Journal of Applied Mathematics, 2012
The finite difference method discretization of Helmholtz equations usually leads to the large spare linear systems. Since the coefficient matrix is frequently indefinite, it is difficult to solve iteratively.
Shi-Liang Wu, Cui-Xia Li
doaj   +1 more source

Preconditioners for the Spectral Multigrid Method [PDF]

IMA Journal of Numerical Analysis, 1986
Spectral discretizations for elliptic equations have better approximation properties than finite-difference or finite-element methods and are most effective for problems with smooth solution. But they yield full systems of algebraic equations and large condition numbers, f.i. \(O(N^ 2)\). FFT-method enable iterative methods to be nearly as efficient as
Phillips, Timothy N., Zang, Thomas A., Hussaini, M. Yousuff   +2 more
openaire   +2 more sources

Two preconditioners for saddle point problems in fluid flows [PDF]

, 2007
In this paper two preconditioners for the saddle point problem are analysed: one based on the augmented Lagrangian approach and another involving artificial compressibility.
Wubs, F.W., Niet, A.C. de, Wubs, F.W.,, Niet, A.C. de,, Wubs, F.W.; id_orcid   +4 more
core   +1 more source

Enhancing Bubble Removal in Geometry‐Optimized Electrodes

Advanced Engineering Materials, EarlyView.
3D‐printed lattice electrodes outperform stochastic foams in alkaline water electrolysis despite 20%–25% lower surface area. Straight flow channels generate Venturi‐like bubble entrainment, suppressing gas accumulation that renders foam interiors electrochemically inactive.
Florian Wiesner, Peter Förster, Alexander Limper, Anselm Brodersen, Matthias Wessling, John Linkhorst   +5 more
wiley   +1 more source

Scalable block preconditioners for saturated thermo-hydro-mechanics problems

Advanced Modeling and Simulation in Engineering Sciences, 2023
We are interested in the modelling of saturated thermo-hydro-mechanical (THM) problems that describe the behaviour of a soil in which a weakly compressible fluid evolves.
Ana C. Ordonez, Nicolas Tardieu, Carola Kruse, Daniel Ruiz, Sylvie Granet   +4 more
doaj   +1 more source

A Multigrid Preconditioner for the Semiconductor Equations

SIAM Journal on Scientific Computing, 1996
Summary: A multigrid preconditioned conjugate gradient algorithm is introduced into a semiconductor device modeling code DANCIR. This code simulates a wide variety of semiconductor devices by numerically solving the drift-diffusion equations. The most time-consuming aspect of the simulation is the solution of three linear systems within each iteration ...
Juan C. Meza, Ray S. Tuminaro
openaire   +2 more sources

Fast interior point solution of quadratic programming problems arising from PDE-constrained optimization [PDF]

, 2017
Interior point methods provide an attractive class of approaches for solving linear, quadratic and nonlinear programming problems, due to their excellent efficiency and wide applicability.
Gondzio, Jacek, John W. Pearson, Pearson, John, Jacek Gondzio, Pearson, John W   +4 more
core   +1 more source

Solution‐Processed Two‐Dimensional Indium Oxide on Sodium‐Embedded Alumina for Reconfigurable Optoelectronic Synaptic Transistors

Advanced Functional Materials, EarlyView.
Wafer‐scale two‐dimensioanl In2Se3 oxidized into InOx on sodium‐embedded beta‐alumina enables multifunctional reconfigurable electronics. Sodium ions accumulate within distinct spatial distribution under drain‐controlle and gate‐controlled operation. Drain‐control operation gives controllability of ultraviolet‐driven optoelectronic synaptic conductance
Jinhong Min, Yonghyun Albert Kwon, Hyunbin Kim, Jihyun Kim, Myeongjin Jung, Jaewon Heo, Gwang Ya Kim, Vlastimil Mazanek, Zdeněk Sofer, In Soo Kim, Jeong Ho Cho, Hyesung Park, Sang Min Won, Joohoon Kang   +13 more
wiley   +1 more source

Preconditioners based on the ISM factorization

Analele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2015
In this paper we survey our work on preconditioners based on the Inverse Sherman-Morrison factorization. The most important theoretical results are also summarized and some numerical conclusions are provided.
Bru Rafael, Cerdán Juana, Marín José, Mas José, Tůma Miroslav   +4 more
doaj   +1 more source

Preconditioners for Multi-Screen Scattering

2022 International Conference on Electromagnetics in Advanced Applications (ICEAA), 2022
In this contribution, a well-conditioned method for the modelling of scattering by so-called multi-screens or PEC sheets including junctions is introduced. The method starts from the inflated screen approach by Claeys and Hiptmair. We introduce a Calderón preconditioner and a suitable discretisation scheme.
Cools, Kristof, Urzua-Torres, Carolina
openaire   +3 more sources