Displaying similar documents to “Contrôle et stabilisation d'ondes électromagnétiques”

Stabilisation frontière de problèmes de Ventcel

Amar Heminna (2010)

ESAIM: Control, Optimisation and Calculus of Variations

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The problem of boundary stabilization for the isotropic linear elastodynamic system and the wave equation with Ventcel's conditions are considered (see [12]). The boundary observability and the exact controllability were etablished in [11]. We prove here the enegy decay to zero for the elastodynamic system with stationary Ventcel's conditions by introducing a nonlinear boundary feedback. We also give a boundary feedback leading to arbitrarily large energy decay rates for the elastodynamic...

Nouvelles formulations intégrales pour les problèmes de diffraction d'ondes

David P. Levadoux, Bastiaan L. Michielsen (2010)

ESAIM: Mathematical Modelling and Numerical Analysis

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We present an integral equation method for solving boundary value problems of the Helmholtz equation in unbounded domains. The method relies on the factorisation of one of the Calderón projectors by an operator approximating the exterior admittance (Dirichlet to Neumann) operator of the scattering obstacle. We show how the pseudo-differential calculus allows us to construct such approximations and that this yields integral equations without internal resonances and being well-conditioned at...

Remarques sur l'observabilité pour l'équation de Laplace

Kim-Dang Phung (2010)

ESAIM: Control, Optimisation and Calculus of Variations

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We consider the Laplace equation in a smooth bounded domain. We prove logarithmic estimates, in the sense of John [5] of solutions on a part of the boundary or of the domain without known boundary conditions. These results are established by employing Carleman estimates and techniques that we borrow from the works of Robbiano [8,11]. Also, we establish an estimate on the cost of an approximate control for an elliptic model equation.

Un algorithme d'identification de frontières soumises à des conditions aux limites de Signorini

Slim Chaabane, Mohamed Jaoua (2010)

ESAIM: Mathematical Modelling and Numerical Analysis

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This work deals with a non linear inverse problem of reconstructing an unknown boundary , the boundary conditions prescribed on being of Signorini type, by using boundary measurements. The problem is turned into an optimal shape design one, by constructing a Kohn & Vogelius-like cost function, the only minimum of which is proved to be the unknown boundary. Furthermore, we prove that the derivative of this cost function with respect to a direction depends only on the state ...

Correcteurs proportionnels-intégraux généralisés

Michel Fliess, Richard Marquez, Emmanuel Delaleau, Hebertt Sira–Ramírez (2010)

ESAIM: Control, Optimisation and Calculus of Variations

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For constant linear systems we are introducing and , which permit to bypass the derivative term in the classic PID controllers and more generally the usual asymptotic observers. Our approach, which is mainly of algebraic flavour, is based on the module-theoretic framework for linear systems and on operational calculus in Mikusiński's setting. Several examples are discussed.

Unicité et contrôle pour le système de Lamé

Mourad Bellassoued (2010)

ESAIM: Control, Optimisation and Calculus of Variations

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In this paper, we study the uniqueness problem for the Lamé system. We prove that we have the uniqueness property across any non characteristic surface. We also give two results which apply to the boundary controllability for the Lamé system.

Contrôle dynamique de flux dans un système d'attente avec panne

A. Haqiq, N. Mikou (2010)

RAIRO - Operations Research

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We consider two parallel M/M/1 queues. The server at one of the queues is subject to intermittent breakdowns. By the theory of dynamic programming, we determine a threshold optimal policy which consists to transfer, when it is necessary, the customers that arrive at the first queue towards the second queue in order to minimize an instantaneous cost depending of the two queue lengths.