Publications

• Article dans une revue

Numerical Simulation and Experimental Verification of Mechanical Displacements in Piezoelectric Transformer

Faiza Boukazouha, Guylaine Poulin-Vittrant, Mohamed Rguiti, Marc Lethiecq

Abstract Since its invention, piezoelectric transformers (PTs) have been extensively studied and its performances have been continuously improved. Nowadays, such devices are designed in sophisticated architectures with associated models describing their behavior quite accurately. However, the…

Advanced Theory and Simulations, 2025, 8 (8), pp.2401232. ⟨10.1002/adts.202401232⟩. ⟨hal-05285962⟩

• Poster de conférence

Etude par DFT de l'impact du dopage au Sr sur les propriétés structurales, électroniques, piézoélectriques et ferroélectriques du BaTiO3

Hicham Kacimi-Naciri, Mohamed Rguiti, Ahmed Bachar, Assia Mabrouk, Mohamed Aymen Ben Achour, Christian Courtois, Yannick Lorgouilloux

Cette étude vise à optimiser les matériaux piézoélectriques sans plomb pour diverses applications. En associant modélisation avancée (Wien2k, DFT) et analyses expérimentales, nous avons examiné l'effet du dopage au strontium (Sr) dans les pérovskites Ba1-xSrxTiO3 (BST). La simulation théorique…

Mardi des chercheurs, Apr 2025, Valenciennes (Nord), Lille, France. ⟨hal-05583559⟩

• Poster de conférence

Etude sur la synthèse de de phosphate de calcium biphasique dopé

Vincent Gillet, Marie Lasgorceix, Florian Jean, Stéphane Hocquet, Anne Leriche

Mardi des Chercheurs 2025, Apr 2025, Valenciennes, France. ⟨hal-05582994⟩

• Poster de conférence

Influence de la quantité de verre résiduel et la microstructure des vitrocéramiques polaires piézoélectriques sur la propagation des ondes acoustiques de surface (SAW)

Oussama Zwein, Marc Duquennoy, Dame Fall, Maurice Gonon, Zakariae Oumekloul, Christian Courtois

GFC 18, Mar 2025, Orléans, France. ⟨hal-05063490⟩

• Poster de conférence

Study on the synthesis of doped biphasic calcium phosphate., Etude sur la synthèse de de phosphate de calcium biphasique dopé.

Vincent Gillet, Marie Lasgorceix, Florian Jean, Stéphane Hocquet, Anne Leriche

Parmi les substituts osseux synthétiques couramment utilisés en médecine, deux types de phosphates de calcium sont principalement employés : le β-phosphate tricalcique (β-TCP, β-Ca₃(PO₄)₂) et l’hydroxyapatite (HA, Ca₁₀(PO₄)₆(OH)₂). Le choix du biomatériau dépend du type d’intervention chirurgicale…

Journées Annuelles du Groupe Français de la Céramique (GFC) 2025, Mar 2025, Orléans, France. ⟨hal-05583026⟩

• Pré-publication, Document de travail

Estimating weak Markov-switching AR(1) models

Yacouba Boubacar Mainassara, Armel Bra, Landy Rabehasaina

In this paper, we present the asymptotic properties of the moment estimator for autoregressive (AR for short) models subject to Markovian changes in regime under the assumption that the errors are uncorrelated but not necessarily independent. We relax the standard independence assumption on the…

2025. ⟨hal-04975822⟩

• Pré-publication, Document de travail

Spatially Controlled Evolution of Composite Materials via Stochastic Partial Differential Equations

Nacira Agram, Isabelle Turpin, Eya Zougar

This paper investigates a class of controlled stochastic partial differential equations (SPDEs) arising in the modeling of composite materials with spatially varying properties. The state equation describes the evolution of a material property, influenced by control inputs that adjust the…

2026. ⟨hal-05479840⟩

• Pré-publication, Document de travail

Estimation of subcritical Galton Watson processes with correlated immigration

Yacouba Boubacar Mainassara, Landy Rabehasaina

We consider an observed subcritical Galton Watson process $\{Y_n,\ n\in \mathbb{Z} \}$ with correlated stationary immigration process $\{\epsilon_n,\ n\in \mathbb{Z} \}$. Two situations are presented. The first one is when $\mbox{Cov}(\epsilon_0,\epsilon_k)=0$ for $k$ larger than some $k_0$: a…, Nous considérons un processus observé de Galton Watson $\{Y_n,\ n\in \mathbb{Z} \}$ avec immigration modélisé par un processus corrélé $\{\epsilon_n,\ n\in \mathbb{Z} \}$. Nous présentons des résultats d’estimation du taux de reproduction et l’espérance de l’immigration dans deux situations. La…

2025. ⟨hal-04549758v2⟩

• Pré-publication, Document de travail

Gaussian Process-driven Hidden Markov Models for Early Diagnosis of Infant Gait Anomalies

Luis Torres-Torres F., Jonatan Arias-García, Hernán F. García, Andrés F. López-Lopera, Jesús F. Vargas-Bonilla

Gait analysis is critical in the early detection and intervention of motor neurological disorders in infants. Despite its importance, traditional methods often struggle to model the high variability and rapid developmental changes inherent to infant gait. To address these challenges, we propose a…

2025. ⟨hal-04937628⟩

• Pré-publication, Document de travail

Null controllability of a highly coupled fourth-order parabolic system with one internal control

Nicolás Carreño, Eduardo Cerpa, Emmanuelle Crépeau, Claudia Moreno

<div><p>Controlling systems of partial differential equations with fewer controls than states has been a central topic in the last decades. The nature of the equations and existing couplings are key factors to consider. Even if we can find several works for parabolic systems, there are…

2025. ⟨hal-04934479⟩