Publicaciones

• Article dans une revue

Stabilization by switching time–delay

Kaïs Ammari, Serge Nicaise, Cristina Pignotti

In this paper we consider some stabilization problems for the wave equation with switching time-delay. We prove exponential stability results for appropriate damping coefficients. The proof of the main results is based on D'Alembert formula, observability inequality and some energy estimates....

Asymptotic Analysis, 2013, 83 (3), pp.263-283. ⟨10.3233/ASY-131163⟩. ⟨hal-03138782⟩

• Article dans une revue

Realizable Galois module classes over the group ring for non abelian extensions, Classes galoisiennes réalisables sur l’anneau de groupe d’extensions non abéliennes

Nigel Byott, Bouchaïb Sodaïgui

Given an algebraic number field k and a finite group T, we write R(Ok[T]) for the subset of the locally free classgroup Cl(Ok[T]) consisting of the classes of rings of integers ON in tame Galois extensions N/k with Gal(N/k) T = T. We determine R(Ok[T]), and show it is a subgroup of Cl(Ok[T]) by...

Annales de l'Institut Fourier, 2013, 63 (1), p. 303-371. ⟨10.5802/aif.2762⟩. ⟨hal-03165412⟩

• Article dans une revue

On the asymptotic behavior of transmission thin shell problems

Ismail Merabet, Serge Nicaise, D.A. Chacha

In this paper we study the asymptotic behavior of two-dimensional transmission problems for the linear Koiter model of an elastic multi-structure composed of two thin shells with the same thickness ε<<1. Contrary to the case of membrane shells, the formal limit problem, i.e., for ε=0, fails...

Asymptotic Analysis, 2013, 82 (1-2), p. 163-185. ⟨10.3233/ASY-121144⟩. ⟨hal-03163628⟩

• Communication dans un congrès

Courbes algébriques-trigonométriques à holographe pythagorien et leur utilisation pour résoudre le problème d'interpolation de Hermite

Laura Saini, Lucia Romani, Gudrun Albrecht

Journées de modélisation géométrique, 2013, Marseille, France. ⟨hal-03187567⟩

• Article dans une revue

Polynomial decay rate for a wave equation with general acoustic boundary feedback laws

Serge Nicaise, Zainab Abbas

We consider the stabilization of the wave equation by a general class of acoustic boundary feedback laws at one extremity. This system is not uniformly stable but we furnish sufficient conditions that guarantee a polynomial stability. Our method combines the use of an observability inequality for...

SeMA Journal: Boletin de la Sociedad Española de Matemática Aplicada, 2013, 61 (1), pp.19-48. ⟨10.1007/s40324-013-0002-5⟩. ⟨hal-03134810⟩

• Article dans une revue

Dispersive waves with multiple tunnel effect on star shaped networks

Felix Ali Mehmeti, Robert Haller-Dintelmann, Virginie Régnier

We consider the Klein-Gordon equation on a star-shaped network composed of n half-axes connected at their origins. We add a potential which is constant but dierent on each branch. The corresponding spatial operator is self-adjoint and we state explicit expressions for its resolvent and its...

Discrete and Continuous Dynamical Systems - Series S, 2013, 6 (3), pp.783-791. ⟨10.3934/dcdss.2013.6.783⟩. ⟨hal-03227666⟩

• Article dans une revue

DIELECTRIC AND PIEZOELECTRIC PROPERTIES OF LEAD-FREE ( Bi 0.5 Na 0.5 ) 0.94 Ba 0.06 TiO 3 + x% Ce 2 O 3 + y% La 2 O 3 + z% Y 2 O 3 COMPOUNDS SYNTHESIZED BY SOL–GEL TECHNIQUE

A. Chaouchi, M. Saidi, Sophie d'Astorg, Mohamed Rguiti, Christian Courtois

( Bi 0.5 Na 0.5 ) 0.94 Ba 0.06 TiO 3 + x% Ce 2 O 3 + y% La 2 O 3 + z% Y 2 O 3 compounds (named BNT–BT– x/y/z) were synthesized by a sol–gel technique, for (x,y,z) = (0,0,0), (0.25, 0.25, 0.25), (0.25, 0.5, 0.5), (0.5, 0.25, 0.25) and (0.5, 0.5, 0.25). The structural variation according to the...

Journal of Advanced Dielectrics, 2013, 02 (04), pp.1250022. ⟨10.1142/S2010135X12500221⟩. ⟨hal-04281123⟩

• Article dans une revue

On Riemann and Weyl compatible tensors

Ryszard Deszcz, Małgorzata Głogowska, Jan Jełowicki, Miroslava Petrović-Torgašev, Georges Zafindratafa

We investigate semi-Riemannian manifolds satisfying some curvature conditions. Those conditions are strongly related to pseudosymmetry.

Publications de l'Institut Mathématique., 2013, 94 (108), pp.111-124. ⟨10.2298/PIM1308111D⟩. ⟨hal-03146560⟩

• Article dans une revue

Robust Approximation of Singularly Perturbed Delay Differential Equations by the hp Finite Element Method

Serge Nicaise, Xenophontos Christos

Abstract. We consider the finite element approximation of the solution to a singularly perturbed second order differential equation with a constant delay. The boundary value problem can be cast as a singularly perturbed transmission problem, whose solution may be decomposed into a smooth part, a...

Computational Methods in Applied Mathematics, 2013, 13 (1), pp.21-37. ⟨10.1515/cmam-2012-0001⟩. ⟨hal-03212509⟩

• Chapitre d'ouvrage

Prediction of Long-Term Chemical Evolution of a Low-pH Cement Designed for Underground Radioactive Waste Repositories

Thi Thuy Ha Bach, Isabelle Pochard, Céline Cau-Dit-Coumes, Cyrille Mercier, André Nonat

Low-pH cements, also referred as low-alkalinity cements, are binders with a pore solution pH ≤ 11. They can be designed by replacing significant amounts of Portland cement (OPC) (≥40 %) by silica fume, which can be associated in some cases to low-CaO fly ash and/or ground granulated blast furnace...

Cement-Based Materials for Nuclear Waste Storage, Springer, pp.239-249, 2013, 9781489989680. ⟨10.1007/978-1-4614-3445-0_21⟩. ⟨hal-03065972⟩