Publications

• Article dans une revue

On some curvature conditions of pseudosymmetry type

Ryszard Deszcz, Małgorzata Głogowska, Marian Hotloś, Georges Zafindratafa

It is known that the difference tensor R⋅C−C⋅R and the Tachibana tensor Q(S,C) of any semi-Riemannian Einstein manifold (M,g) of dimension n≥4 are linearly dependent at every point of M. More precisely R⋅C−C⋅R=(1/(n−1))Q(S,C) holds on M. In the paper we show that there are quasi-Einstein, as well…

Periodica Mathematica Hungarica, 2015, 70 (2), pp.153-170. ⟨10.1007/s10998-014-0081-9⟩. ⟨hal-03146519⟩

• Article dans une revue

Impedance spectroscopy studies on (Na0.5Bi0.5)0.94Ba0.06TiO3 + 0.3 wt% Sm2O3 + 0.25 wt% LiF lead-free piezoelectric ceramics

N. Zidi, Ahcène Chaouchi, Sophie d'Astorg, Mohamed Rguiti, Christian Courtois

The a.c. complex impedance spectroscopy technique was used to obtain the electrical parameters of (Na0.5Bi0.5)0.94Ba0.06TiO3 +0.3 wt% Sm2O3 +0.25 wt% LiF lead-free ceramics in a wide frequency range at different temperatures. These samples were prepared by a high-temperature solid-state reaction…

Bulletin of Materials Science, 2015, 38 (3), pp.731-737. ⟨10.1007/s12034-015-0888-x⟩. ⟨hal-03039132⟩

• Article dans une revue

Solving the biharmonic Dirichlet problem on domains with corners

Colette De Coster, Serge Nicaise, Guido Sweers

The biharmonic Dirichlet boundary value problem on a bounded domain is the focus of the present paper. By Riesz’ representation theorem the existence and uniqueness of a weak solution is quite direct. The problem that we are interested in appears when one is looking for constructive approximations…

Mathematical News / Mathematische Nachrichten, 2015, 288 (8-9), pp.854-871. ⟨10.1002/mana.201400022⟩. ⟨hal-03142424⟩

• Communication dans un congrès

A propos des points massiques

Jean-Paul Becar

Journée “Exposons-Nous”, Université de Valenciennes et du Hainaut-Cambrésis, May 2015, Valenciennes, France. ⟨hal-03132898⟩

• Communication dans un congrès

Generating quadric design elements by means of geometry and optimization

Gudrun Albrecht, Marco Paluszny, Marianela Lentini

Modelling, Computation and Optimization in Information Systems and Management Sciences, May 2015, Metz, France. ⟨hal-03155994⟩

• Article dans une revue

Stability analysis of a class of uncertain switched systems on time scale using Lyapunov functions

Fatima Zohra Taousser, Michael Defoort, Mohamed Djemai

This paper deals with the stability analysis of a class of uncertain switched systems on non-uniform time domains. The considered class consists of dynamical systems which commute between an uncertain continuous-time subsystem and an uncertain discrete-time subsystem during a certain period of time…

Nonlinear Analysis: Hybrid Systems, 2015, 16, pp.13-23. ⟨10.1016/j.nahs.2014.12.001⟩. ⟨hal-03184519⟩

• Article dans une revue

Stability of abstract–wave equation with delay and a Kelvin–Voigt damping

Kaïs Ammari, Serge Nicaise, Cristina Pignotti

In this paper we consider a stabilization problem for an abstract wave equation with delay and a Kelvin-Voigt damping. We prove an exponential stability result for appropriate damping coefficients. The proof of the main result is based on a frequency-domain approach.

Asymptotic Analysis, 2015, 95 (1-2), pp.21-38. ⟨10.3233/ASY-151317⟩. ⟨hal-03138786⟩

• Article dans une revue

Error analysis for a mixed DG method for folded Naghdi's shell, Analyse d'erreur pour une méthode de Galerkin discontinue mixte pour une coque de Naghdi pliée

Serge Nicaise, Ismail Merabet

In this Note, we perform some error analyses of a mixed discontinuous formulation for Naghdi's equations for thin linearly elastic shells. Using a combination between the a priori and the a posteriori techniques, we derive a quasi-optimal a priori error estimate and an efficient and reliable a…, Dans cette Note, nous fournissons des estimations d'erreur d'une méthode d'éléments finis discontinus mixte proposée pour résoudre les équations du modèle de Naghdi de coques linéairement élastiques. En utilisant une combinaison entre les techniques de l'analyse a priori et…

Comptes Rendus. Mathématique, 2015, 353 (7), pp.659-664. ⟨10.1016/j.crma.2015.04.017⟩. ⟨hal-03158953⟩

• Article dans une revue

SPECIAL LAGRANGIAN 4-FOLDS WITH SO(2)⋊S3-SYMMETRY IN COMPLEX SPACE FORMS

Franki Dillen, Christine Scharlach, Kristof Schoels, Luc Vrancken

In this article we obtain a classification of special Lagrangian submanifolds in complex space forms subject to a pointwise SO(2)⋊S3-symmetry on the second fundamental form. The algebraic structure of this form has been obtained by Marianty Ionel in [8]. However, the classification of special…

Taiwanese Journal of Mathematics, TJM, 2015, 19 (3), pp.759-792. ⟨10.11650/tjm.19.2015.4951⟩. ⟨hal-03148413⟩

• Article dans une revue

Dielectric, ferroelectrics properties and impedance spectroscopy analysis of the [(Na0.535K0.480)0.966Li0.058](Nb0.90Ta0.10)O3-based lead-free ceramics

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

Polycrystalline of [(Na0.535K0.480)0.966Li0.058](Nb0.90Ta0.10)O3 samples were prepared using the high-temperature solid-state reaction technique. X-ray diffraction (XRD) analysis indicates the formation of a single-phase with orthorhombic structure. AC impedance plots were used as tool to analyze…

Journal of Advanced Dielectrics, 2015, 05 (01), 7 p. ⟨10.1142/S2010135X15500071⟩. ⟨hal-03116581⟩