Publications

• Article dans une revue

Every centroaffine Tchebychev hyperovaloid is ellipsoid

Xiuxiu Cheng, Zejun Hu, Luc Vrancken

We study locally strongly convex Tchebychev hypersurfaces, namely the centroaffine totally umbilical hypersurfaces, in the (n+1)-dimensional affine space Rn+1. We first make an ordinary-looking observation that such hypersurfaces are characterized by having a Riemannian structure admitting a…

Pacific Journal of Mathematics, 2021, 315 (1), pp.27-44. ⟨10.2140/pjm.2021.315.27⟩. ⟨hal-03722505⟩

• Article dans une revue

The 2d-directed spanning forest converges to the Brownian web

David Coupier, Kumarjit Saha, Anish Sarkar, Viet Chi Tran

The two-dimensional directed spanning forest (DSF) introduced by Baccelli and Bordenave is a planar directed forest whose vertex set is given by a homogeneous Poisson point process $\mathcal{N}$ on $\mathbb{R}^2$. If the DSF has direction $-e_y$, the ancestor $h(u)$ of a vertex $u \in \mathcal{N}$…

The Annals of Probability, 2021, 49 (1), pp.435-484. ⟨10.1214/20-AOP1478⟩. ⟨hal-01798763v3⟩

• Article dans une revue

Linear hyperbolic systems on networks: well-posedness and qualitative properties

Marjeta Kramar Fijavž, Delio Mugnolo, Serge Nicaise

We study hyperbolic systems of one-dimensional partial differential equations under general, possibly non-local boundary conditions. A large class of evolution equations, either on individual 1-dimensional intervals or on general networks, can be reformulated in our rather flexible formalism, which…

ESAIM: Control, Optimisation and Calculus of Variations, 2021, 27, pp.7. ⟨10.1051/cocv/2020091⟩. ⟨hal-03158486⟩

• Article dans une revue

Affine hypersurfaces with constant sectional curvature

Miroslava Antić, Haizhong Li, Luc Vrancken, Xianfeng Wang

We use a new approach to study locally strongly convex hypersurfaces with constant sectional curvature in the affine space (Formula presented). We prove a nice relation involving the eigenvalues of the shape operator S and the difference tensor K of the affine hypersurface. This is achieved by…

Pacific Journal of Mathematics, 2021, 310 (2), pp.275-302. ⟨10.2140/pjm.2021.310.275⟩. ⟨hal-03722534⟩

• Article dans une revue

Piezoelectric and Electromechanical Characteristics of Porous Poly(Ethylene-co-Vinyl Acetate) Copolymer Films for Smart Sensors and Mechanical Energy Harvesting Applications

Chouaib Ennawaoui, Abdelowahed Hajjaji, Cédric Samuel, Erroumayssae Sabani, Abdelkader Rjafallah, Ikrame Najihi, El Mehdi Laadissi, El Mehdi Loualid, Mohamed Rguiti, Abdessamad El Ballouti, Azeddine Azim

This paper investigates energy harvesting performances of porous piezoelectric polymer films to collect electrical energy from vibrations and power various sensors. The influence of void content on the elastic matrix, dielectric, electrical, and mechanical properties of porous piezoelectric polymer…

Applied System Innovation, 2021, 4 (3), pp.57. ⟨10.3390/asi4030057⟩. ⟨hal-03703173⟩

• Article dans une revue

An optimal control problem governed by heat equation with nonconvex constraints applied to selective laser melting process

Tonia-Maria Alam, Serge Nicaise, Luc Paquet

This paper deals with a PDE-constraints optimal control problem applied to an Additive Manufacturing process, namely a selective laser melting. Here, we want to control the temperature gradient inside the domain during a fixed time of heating, by acting on the trajectory of the dynamic Gaussian…

Minimax Theory and its Applications, 2021, 6 (2), pp.191-204. ⟨hal-02302403⟩

• HDR

Optimisation des voies alcoolates pour l'élaboration de matériaux céramiques oxydes et de revêtements fonctionnels en réponse aux problématiques environnementales, Optimization of alcoholate routes for the development of oxide ceramic materials and functional coating in response to environmental issues

Philippe Champagne

Le LMCPA est réputé depuis 2000 pour sa capacité à créer diverses pièces céramiques à géométries variables dotées de propriétés remarquables (hautes résistances thermique et mécanique, piézoélectricité, etc ...) et pour sa capacité à synthétiser les poudres nécessaires à cette fabrication. Sur ce…, LMCPA has been renowned since 2000 for its ability to create various ceramic parts with variable geometries endowed with remarkable properties (high thermal and mechanical resistance, piezoelectricity, etc) and for its ability to synthesize the powders necessary for this manufacture. On this last…

• Thèse

Quelques problèmes de contrôle optimal d'équations aux dérivées partielles et applications au procédé de fusion sélective par laser (SLM), Some optimal control problems of partial differential equations and applications to the selective laser melting process (SLM)

Tonia-Maria Alam

Dans cette thèse, nous étudions quelques problèmes de contrôle optimaldes équations aux dérivées partielles avec appliqués au procédé de fusion sélective parlaser. La thèse se compose de quatre chapitres. Dans le chapitre 1, nous introduisonsle sujet de la thèse et nous présentons les principaux…, In this thesis, we study optimal control problems of partial differential equations withan application to the selective laser melting process. The thesis consists of four chapters.In chapter 1, we introduce the topic of the thesis and we present the main results.Chapter 2 deals with an optimal…

Optimisation et contrôle [math.OC]. Université Polytechnique Hauts-de-France, 2020. Français. ⟨NNT : 2020UPHF0022⟩. ⟨tel-03390313⟩

• Article dans une revue

Modification of hydroxyapatite surface properties by electron irradiation

Guillaume Bai, Jean-Christophe Hornez, Ulrich Maschke, Philippe Supiot, Etienne Bres

In the present work, the modification of wetting properties of EB irradiated HA ceramics are studied under air and N2 gas atmospheres. We show a noticeable increase of the hydrophily of electron irradiated HA ceramics in an air atmosphere and a lesser increase when the samples are irradiated in an…

Radiation Physics and Chemistry, 2020, Radiation Physics and Chemistry, 177, pp.109192. ⟨10.1016/j.radphyschem.2020.109192⟩. ⟨hal-03104388⟩

• Article dans une revue

Flash point prediction with UNIFAC type models of ethylic biodiesel and binary/ternary mixtures of FAEEs

Débora Costa Do Nascimento, Natália Daniele Dorighello Carareto, Antonio Marinho Barbosa Neto, Vincent Gerbaud, Mariana Conceição da Costa

In order to guarantee safe handling of a combustible liquid, such as biodiesel, it is important to be aware of its Flash Point (FP). Thus, the present study focused on FP experimental measurement and thermodynamic correlation of binary and ternary mixtures of saturated or unsaturated fatty acid…

Fuel, 2020, 281, pp.118717. ⟨10.1016/j.fuel.2020.118717⟩. ⟨hal-03115520⟩