L2-approximation by the translates of a function and related attenuation factors.
We investigate sufficient and possibly necessary conditions for the L2 stability of the upwind first order finite volume scheme for Maxwell equations, with metallic and absorbing boundary conditions. We yield a very general sufficient condition, valid for any finite volume partition in two and three space dimensions. We show this condition is necessary for a class of regular meshes in two space dimensions. However, numerical tests show it is not necessary in three space dimensions even on regular...
In this work, we present an introduction to automatic differentiation, its use in optimization software, and some new potential usages. We focus on the potential of this technique in optimization. We do not dive deeply in the intricacies of automatic differentiation, but put forward its key ideas. We sketch a survey, as of today, of automatic differentiation software, but warn the reader that the situation with respect to software evolves rapidly. In the last part of the paper, we present some...
L’objet de cet article est de présenter le manuscrit original, jusqu’alors inconnu, de Cholesky où il explique sa méthode de résolution des systèmes d’équations linéaires. Le contexte historique est précisé après une brève biographie. La méthode des moindres carrés et son application à la topographie, ainsi que les diverses méthodes directes de résolution des systèmes linéaires sont discutées. Ensuite, la diffusion de la méthode de Cholesky est retracée et l’on donne une analyse détaillée du manuscrit...
In this paper, the Babuška’s theory of Lagrange multipliers is extended to higher order elliptic Dirichlet problems. The resulting variational formulation provides an efficient numerical squeme in meshless methods for the approximation of elliptic problems with essential boundary conditions.
In this paper, the Babuška's theory of Lagrange multipliers is extended to higher order elliptic Dirichlet problems. The resulting variational formulation provides an efficient numerical squeme in meshless methods for the approximation of elliptic problems with essential boundary conditions.