All a b c d e f g h i j k l m n o p q r s t u v w x y z Other

Previous Page 5 Next

Displaying 81 – 100 of 112

Showing per page

On the quality of local flux reconstructions for guaranteed error bounds

Vejchodský, Tomáš (2015)

Application of Mathematics 2015

In this contribution we consider elliptic problems of a reaction-diffusion type discretized by the finite element method and study the quality of guaranteed upper bounds of the error. In particular, we concentrate on complementary error bounds whose values are determined by suitable flux reconstructions. We present numerical experiments comparing the performance of the local flux reconstruction of Ainsworth and Vejchodsky [2] and the reconstruction of Braess and Schöberl [5]. We evaluate the efficiency...

On using artificial compressibility method for solving turbulent flows

Louda, Petr, Kozel, Karel, Příhoda, Jaromír (2012)

Applications of Mathematics 2012

In this work, artificial compressibility method is used to solve steady and unsteady flows of viscous incompressible fluid. The method is based on implicit higher order upwind discretization of Navier-Stokes equations. The extension for unsteady simulation is considered by increasing artificial compressibility parameter or by using dual time stepping. The methods are tested on laminar flow around circular cylinder and used to simulate turbulent unsteady flows by URANS approach. The simulated cases...

Parallel programming and optimization of heat radiation intensity

Mlýnek, Jaroslav, Srb, Radek (2013)

Applications of Mathematics 2013

This article focuses on the practical possibilities of a suitable use of parallel programming during the computational processing of heat radiation intensity optimization across the surface of an aluminium or nickel mould. In practice, an aluminium or nickel mould is first preheated by infrared heaters located above the outer mould surface. Then the inner mould surface is sprinkled with a special PVC powder and the outer mould surface is continually warmed by infrared heaters. This is an energy-efficient...

Path-following the static contact problem with Coulomb friction

Haslinger, Jaroslav, Janovský, Vladimír, Kučera, Radek (2013)

Applications of Mathematics 2013

Consider contact problem with Coulomb friction on two planar domains. In order to find non-unique solutions we propose a new path following algorithm: Given a linear loading path we approximate the corresponding solution path. It consists of oriented piecewise linear branches connected by transition points. We developed a) predictor-corrector algorithm to follow oriented linear branches, b) branching and orientation indicators to detect transition points. The techniques incorporate semi-smooth Newton...

Preface

Christian Choffrut, Juhani Karhumäki (1994)

RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications

Preface

Rama Cont, Jean-Pierre Fouque, Bernard Lapeyre (2007)

ESAIM: Probability and Statistics

Preface

Segeth, K. (2015)

Application of Mathematics 2015

Preface

Segeth, Karel (2012)

Applications of Mathematics 2012

Preface

Michael Hrušák, David Chodounský, Tomáš Jech (2018)

Commentationes Mathematicae Universitatis Carolinae

Riemann solution for hyperbolic equations with discontinuous coefficients

Remaki, L. (2013)

Applications of Mathematics 2013

This paper deals with a Riemann solution for scalar hyperbolic equations with discontinuous coefficients. In many numerical schemes of Godunov type in fluid dynamics, electromagnetic and so on, usually hyperbolic problems are solved to estimate fluxes. The exact solution is generally difficult to obtain, but good approximations are provided in many situations like Roe and HLLC Riemann solvers in fluid. However all these solvers assumes that the acoustic waves speeds are continuous which is not...

Shoaling of nonlinear steady waves: maximum height and angle of breaking

Franco, Sebastião Romero, Farina, Leandro (2015)

Application of Mathematics 2015

A Fourier approximation method is used for modeling and simulation of fully nonlinear steady waves. The set of resulting nonlinear equations are solved by Newton's method. The shoaling of waves is simulated based on comparisons with experimental data. The wave heights and the angles of breaking are analysed until the limit of inadequacy of the numerical method. The results appear quite close to those criteria predicted by the theory of completely nonlinear surface waves and contribute to provide...

Smooth approximation and its application to some 1D problems

Segeth, Karel (2012)

Applications of Mathematics 2012

In the contribution, we are concerned with the exact interpolation of the data at nodes given and also with the smoothness of the interpolating curve and its derivatives. This task is called the problem of smooth approximation of data. The interpolating curve or surface is defined as the solution of a variational problem with constraints. We discuss the proper choice of basis systems for this way of approximation and present the results of several 1D numerical examples that show the quality of smooth...

Solutions of hypersingular integral equations over circular domains by a spectral method

Farina, Leandro, Ziebell, Juliana S. (2013)

Applications of Mathematics 2013

The problem of a solving a class of hypersingular integral equations over the boundary of a nonplanar disc is considered. The solution is obtained by an expansion in basis functions that are orthogonal over the unit disc. A Fourier series in the azimuthal angle, with the Fourier coefficients expanded in terms of Gegenbauer polynomials is employed. These integral equations appear in the study of the interaction of water waves with submerged thin plates.

Some practical aspects of parallel adaptive BDDC method

Šístek, Jakub, Mandel, Jan, Sousedík, Bedřich (2012)

Applications of Mathematics 2012

We describe a parallel implementation of the Balancing Domain Decomposition by Constraints (BDDC) method enhanced by an adaptive construction of coarse problem. The method is designed for numerically difficult problems, where standard choice of continuity of arithmetic averages across faces and edges of subdomains fails to maintain the low condition number of the preconditioned system. Problems of elasticity analysis of bodies consisting of different materials with rapidly changing stiffness may...

Some remarks on mixed approximation problem

Sýkorová, Irena (2015)

Application of Mathematics 2015

Several years ago, we discussed the problem of approximation polynomials with Milan Práger. This paper is a natural continuation of the work we collaborated on. An important part of numerical analysis is the problem of finding an approximation of a given function. This problem can be solved in many ways. The aim of this paper is to show how interpolation can be combined with the Chebyshev approximation.

Currently displaying 81 – 100 of 112