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Sur une méthode itérative de résolution de problèmes aux limites elliptiques non linéaires

Moïse Sibony (1977)

Aplikace matematiky

Soit A un opérateur non nécessairement linéaire d’un Hilbert de l’équation A u = f , pour f donné dans ' . Nous étudions la convergence du schéma itératif suivant: u n + 1 = u n - ρ B - 1 ( A u n - f ) aou B est fonction d’un opérateur auto-adjoint S choisi de telle sorte que l’inversion de B soit immédiate numériquement. Par exemple B = [ I - ( I - ρ 0 S ) m ] - 1 S avec un entier m et une constante ρ 0 convenablement choisis. Nous appliquons les résultats à un problème aux limites non linéaires avec résultats numériques.

Surface integral and Gauss-Ostrogradskij theorem from the viewpoint of applications

Alexander Ženíšek (1999)

Applications of Mathematics

Making use of a surface integral defined without use of the partition of unity, trace theorems and the Gauss-Ostrogradskij theorem are proved in the case of three-dimensional domains Ω with a Lipschitz-continuous boundary for functions belonging to the Sobolev spaces H 1 , p ( ) ( 1 ...

Sweeping preconditioners for elastic wave propagation with spectral element methods

Paul Tsuji, Jack Poulson, Björn Engquist, Lexing Ying (2014)

ESAIM: Mathematical Modelling and Numerical Analysis - Modélisation Mathématique et Analyse Numérique

We present a parallel preconditioning method for the iterative solution of the time-harmonic elastic wave equation which makes use of higher-order spectral elements to reduce pollution error. In particular, the method leverages perfectly matched layer boundary conditions to efficiently approximate the Schur complement matrices of a block LDLT factorization. Both sequential and parallel versions of the algorithm are discussed and results for large-scale problems from exploration geophysics are presented....

Symplectic Pontryagin approximations for optimal design

Jesper Carlsson, Mattias Sandberg, Anders Szepessy (2009)

ESAIM: Mathematical Modelling and Numerical Analysis - Modélisation Mathématique et Analyse Numérique

The powerful Hamilton-Jacobi theory is used for constructing regularizations and error estimates for optimal design problems. The constructed Pontryagin method is a simple and general method for optimal design and reconstruction: the first, analytical, step is to regularize the hamiltonian; next the solution to its stationary hamiltonian system, a nonlinear partial differential equation, is computed with the Newton method. The method is efficient for designs where the hamiltonian function can be...

Symplectic Pontryagin approximations for optimal design

Jesper Carlsson, Mattias Sandberg, Anders Szepessy (2008)

ESAIM: Mathematical Modelling and Numerical Analysis

The powerful Hamilton-Jacobi theory is used for constructing regularizations and error estimates for optimal design problems. The constructed Pontryagin method is a simple and general method for optimal design and reconstruction: the first, analytical, step is to regularize the Hamiltonian; next the solution to its stationary Hamiltonian system, a nonlinear partial differential equation, is computed with the Newton method. The method is efficient for designs where the Hamiltonian function...

Currently displaying 1881 – 1900 of 2193