Über eine neue Methode zur Lösung gewisser Variationsprobleme der mathematischen Physik.
Ueber eine neue Methode zur Lösung gewisser Randwertaufgaben
Un formalisme pour les estimations de type Kružkov pour les lois de conservation scalaires
On montre comment le formalisme introduit récemment par l’auteur et Benoît Perthame permet de justifier la plupart des estimations d’erreurs pour des solutions approchées d’une loi de conservation scalaire.
Un résultat de convergence d'ordre deux en temps pour l'approximation des équations de Navier–Stokes par une technique de projection incrémentale
The Navier–Stokes equations are approximated by means of a fractional step, Chorin–Temam projection method; the time derivative is approximated by a three-level backward finite difference, whereas the approximation in space is performed by a Galerkin technique. It is shown that the proposed scheme yields an error of for the velocity in the norm of l2(L2(Ω)d), where l ≥ 1 is the polynomial degree of the velocity approximation. It is also shown that the splitting error of projection schemes based...
Unconditionally Stable Explicit Methods for Parabolic Equations.
Une famille de schémas numériques T.V.D. pour les lois de conservation hyperboliques
Une méthode multipas implicite-explicite pour l'approximation des équations d'évolution paraboliques.
Une norme « naturelle » pour la méthode des caractéristiques en éléments finis discontinus : cas 1-D
Une note sur les méthodes de caractéristiques et de Lesaint-Raviart pour les problèmes hyperboliques stationnaires
Uniform a priori estimates for discrete solution of nonlinear tensor diffusion equation in image processing
This paper concerns with the finite volume scheme for nonlinear tensor diffusion in image processing. First we provide some basic information on this type of diffusion including a construction of its diffusion tensor. Then we derive a semi-implicit scheme with the help of so-called diamond-cell method (see [Coirier1] and [Coirier2]). Further, we prove existence and uniqueness of a discrete solution given by our scheme. The proof is based on a gradient bound in the tangential direction by a gradient...
Uniform convergence of monotone iterative methods for semilinear singularly perturbed problems of elliptic and parabolic types.
Uniform stability of linear multistep methods in Galerkin procedures for parabolic problems.
Uniform stabilization of a viscous numerical approximation for a locally damped wave equation
This work is devoted to the analysis of a viscous finite-difference space semi-discretization of a locally damped wave equation in a regular 2-D domain. The damping term is supported in a suitable subset of the domain, so that the energy of solutions of the damped continuous wave equation decays exponentially to zero as time goes to infinity. Using discrete multiplier techniques, we prove that adding a suitable vanishing numerical viscosity term leads to a uniform (with respect to the mesh size)...
Uniformly exponentially or polynomially stable approximations for second order evolution equations and some applications
In this paper, we consider the approximation of second order evolution equations. It is well known that the approximated system by finite element or finite difference is not uniformly exponentially or polynomially stable with respect to the discretization parameter, even if the continuous system has this property. Our goal is to damp the spurious high frequency modes by introducing numerical viscosity terms in the approximation scheme. With these viscosity terms, we show the exponential or polynomial...
Uniformly exponentially stable approximations for a class of second order evolution equations
We consider the approximation of a class of exponentially stable infinite dimensional linear systems modelling the damped vibrations of one dimensional vibrating systems or of square plates. It is by now well known that the approximating systems obtained by usual finite element or finite difference are not, in general, uniformly stable with respect to the discretization parameter. Our main result shows that, by adding a suitable numerical viscosity term in the numerical scheme, our approximations are...
Unique solvability and stability analysis of a generalized particle method for a Poisson equation in discrete Sobolev norms
Unique solvability and stability analysis is conducted for a generalized particle method for a Poisson equation with a source term given in divergence form. The generalized particle method is a numerical method for partial differential equations categorized into meshfree particle methods and generally indicates conventional particle methods such as smoothed particle hydrodynamics and moving particle semi-implicit methods. Unique solvability is derived for the generalized particle method for the...
Uniqueness of critical points for semi-linear Dirichlet problems in convex domains.
Using a graph grammar system in the finite element method
The paper presents a system of Composite Graph Grammars (CGGs) modelling adaptive two dimensional hp Finite Element Method (hp-FEM) algorithms with rectangular finite elements. A computational mesh is represented by a composite graph. The operations performed over the mesh are defined by the graph grammar rules. The CGG system contains different graph grammars defining different kinds of rules of mesh transformations. These grammars allow one to generate the initial mesh, assign values to element...