Mesures de défaut de compacité, application au système de Lamé
Mesures semi-classiques et croisement de modes
L’étude de la dynamique semi-classique d’électrons dans un cristal débouche naturellement sur le problème de l’évolution des mesures semi-classiques en présence d’un croisement de modes. Dans ce travail, nous étudions un système qui présente un tel croisement. À cet effet, nous introduisons des mesures semi-classiques à deux échelles qui décrivent comment la transformée de Wigner usuelle se concentre sur l’ensemble des trajectoires rencontrant ce croisement. Puis nous établissons des formules...
Mesures semi-classiques et mesures de défaut
Method of replacing the variables for generalized symmetry of the D'Alembert equation.
Méthode de Glimm et problème mixte
Méthodes géométriques dans l’étude des équations d’Einstein
L’étude de l’équation des ondes et de ses perturbations a montré l’importance d’un certain nombre d’objets géométriques, tels que les cônes sortants et rentrants, les champs de Lorentz, des repères isotropes adaptés, etc. Parmi les systèmes d’équations hyperboliques non linéaires, les équations d’Einstein jouent un rôle central ; leur étude a nécessité, dans le cas d’un espace-temps courbe, la construction d’objets analogues à ceux du cas plat, cônes, repères adaptés, etc. La construction de ces...
Microlocal analysis and seismic imaging
We study certain Fourier integral operators arising in the inversion of data from reflection seismology.
Microscopic structure of shocks in one conservation laws
Mimetic schemes on non-uniform structured meshes.
Minimal regularity solutions of nonlinear wave equations.
Minimal surfaces in pseudohermitian geometry
We consider surfaces immersed in three-dimensional pseudohermitian manifolds. We define the notion of (p-)mean curvature and of the associated (p-)minimal surfaces, extending some concepts previously given for the (flat) Heisenberg group. We interpret the p-mean curvature not only as the tangential sublaplacian of a defining function, but also as the curvature of a characteristic curve, and as a quantity in terms of calibration geometry. As a differential equation, the p-minimal surface equation...
Mixed problem for semilinear hyperbolic equation of second order with the Dirichlet boundary condition (Preliminary communication)
Mixed problem for semilinear hyperbolic equation of second order with Dirichlet boundary condition
Mixed problem with boundary integral conditions for a class of hyperbolic equations. (Problème mixte avec conditions intégrales pour une classe d'équations hyperboliques.)
Mixed problem with integral conditions for a certain class of hyperbolic equations.
Mixed problems for fully nonlinear hyperbolic equations.
Mixed problems for hyperbolic equations with a small parameter
Model of pulverized coal combustion in a furnace
We describe behavior of the air-coal mixture using the Navier–Stokes equations for gas and particle phases, accompanied by a turbulence model. The undergoing chemical reactions are described by the Arrhenian kinetics (reaction rate proportional to where is temperature). We also consider the heat transfer via conduction and radiation. Moreover we use improved turbulence-chemistry interactions for reaction terms. The system of PDEs is discretized using the finite volume method (FVM) and an advection...
Modeling of vibration for functionally graded beams
In this study, a vibration problem of Euler-Bernoulli beam manufactured with Functionally Graded Material (FGM), which is modelled by fourth-order partial differential equations with variable coefficients, is examined by using the Adomian Decomposition Method (ADM).The method is one of the useful and powerful methods which can be easily applied to linear and nonlinear initial and boundary value problems. As to functionally graded materials, they are composites mixed by two or more materials at a...
Modeling the tip-sample interaction in atomic force microscopy with Timoshenko beam theory
A matrix framework is developed for single and multispan micro-cantilevers Timoshenko beam models of use in atomic force microscopy (AFM). They are considered subject to general forcing loads and boundary conditions for modeling tipsample interaction. Surface effects are considered in the frequency analysis of supported and cantilever microbeams. Extensive use is made of a distributed matrix fundamental response that allows to determine forced responses through convolution and to absorb non-homogeneous...