Displaying 1621 – 1640 of 2184

Showing per page

Parallel implementation of Wavelet-Galerkin method

Finěk, Václav, Šimůnková, Martina (2013)

Programs and Algorithms of Numerical Mathematics

We present here some details of our implementation of Wavelet-Galerkin method for Poisson equation in C language parallelized by POSIX threads library and show its performance in dimensions d { 3 , 4 , 5 } .

Parallel strategies for solving the FETI coarse problem in the PERMON toolbox

Vašatová, Alena, Tomčala, Jiří, Sojka, Radim, Pecha, Marek, Kružík, Jakub, Horák, David, Hapla, Václav, Čermák, Martin (2017)

Programs and Algorithms of Numerical Mathematics

PERMON (Parallel, Efficient, Robust, Modular, Object-oriented, Numerical) is a newly emerging collection of software libraries, uniquely combining Quadratic Programming (QP) algorithms and Domain Decomposition Methods (DDM). Among the main applications are contact problems of mechanics. This paper gives an overview of PERMON and selected ingredients improving scalability, demonstrated by numerical experiments.

Partition of unity method for Helmholtz equation: q -convergence for plane-wave and wave-band local bases

Theofanis Strouboulis, Realino Hidajat (2006)

Applications of Mathematics

In this paper we study the q -version of the Partition of Unity Method for the Helmholtz equation. The method is obtained by employing the standard bilinear finite element basis on a mesh of quadrilaterals discretizing the domain as the Partition of Unity used to paste together local bases of special wave-functions employed at the mesh vertices. The main topic of the paper is the comparison of the performance of the method for two choices of local basis functions, namely a) plane-waves, and b) wave-bands....

Penalties, Lagrange multipliers and Nitsche mortaring

Christian Grossmann (2010)

Discussiones Mathematicae, Differential Inclusions, Control and Optimization

Penalty methods, augmented Lagrangian methods and Nitsche mortaring are well known numerical methods among the specialists in the related areas optimization and finite elements, respectively, but common aspects are rarely available. The aim of the present paper is to describe these methods from a unifying optimization perspective and to highlight some common features of them.

Penalty method and extrapolation for axisymmetric elliptic problems with Dirichlet boundary conditions

Ivan Hlaváček (1990)

Aplikace matematiky

A second order elliptic problem with axisymmetric data is solved in a finite element space, constructed on a triangulation with curved triangles, in such a way, that the (nonhomogeneous) boundary condition is fulfilled in the sense of a penalty. On the basis of two approximate solutions, extrapolates for both the solution and the boundary flux are defined. Some a priori error estimates are derived, provided the exact solution is regular enough. The paper extends some of the results of J.T. King...

Plane wave discontinuous Galerkin methods: Analysis of the h-version

Claude J. Gittelson, Ralf Hiptmair, Ilaria Perugia (2009)

ESAIM: Mathematical Modelling and Numerical Analysis

We are concerned with a finite element approximation for time-harmonic wave propagation governed by the Helmholtz equation. The usually oscillatory behavior of solutions, along with numerical dispersion, render standard finite element methods grossly inefficient already in medium-frequency regimes. As an alternative, methods that incorporate information about the solution in the form of plane waves have been proposed. We focus on a class of Trefftz-type discontinuous Galerkin methods that ...

Currently displaying 1621 – 1640 of 2184