Title: Solving least squares problems by preconditioned iterative methods. Abstract: The efficient solution of large linear least squares problems in which the system matrix contains rows with very different densities is challenging. There have been many classical contributions to solving this problem that focus on direct methods; they can be…
Title: Proximal approaches for matrix optimization problems (joint work with A. Benfenati and J.C. Pesquet) Abstract: Various applications such as gene expression, model selection, graph estimation, or brain network analysis all share very similar matrix variational formulations, namely the minimization, in a symmetric matrix space, of a loss function decoupled…
Modèles de mélange pour la croissance de biofilms Abstract: Nous présentons dans cet exposé la construction de modèles d’EDPs décrivant l’évolution de micro-algues ou de bactéries en interaction entre elles, mais aussi avec leur environnement. Ces modèles sont basés sur la théorie des mélanges et sont couplés avec des équations…
Title: Error estimates in molecular dynamics Abstract: Average properties in molecular systems are typically obtained through ergodic averages of discretizations of certain stochastic differential equations. The timestep discretization leads to biases on the invariant measure which is sampled. I will provide an introduction, aimed at an audience familiar with techniques…
Title : About new constraints induced by 3D printing techniques on the shape optimization process Summary: Although they theoretically make it possible to assemble structures of almost arbitrary complexity – and thus arouse great interest in engineering circles – modern additive manufacturing techniques (or 3D printing) raise new difficulties that…
Title (in french): Analyse de schémas pour une équation de convection et diffusion dégénérée. Abstract (in french): Dans cet exposé nous allons étudier une équation de convection avec un terme de diffusion dégénéré. Cette équation peut être vue comme résultant d’un modèle (simplifié) servant à la modélisation du déplacement de…
Title: Simulations of the magnetic cycles of the Sun and solar-type stars Abstract: The Sun sustains its large-scale magnetic field thanks to its internal turbulent motions through a so-called dynamo effect. Global simulations of the convective dynamo of the Sun and solar-type stars have exhibited in the past decade a…
CanoP, a lightweight C++ framework for adaptive mesh refinement applications Abstract: We will briefly review the different adaptive mesh refivement techniques and their software implementations (cell-based, block-structured and wavelet-based) in order to better emphasize the main specific properties of the library p4est which is the parallel distributed mesh managing engine…
Title : Nuclear core reactor simulations with low-regularity solution Joint work with: Léandre Giret, Erell Jamelot, Félix Kpadonou. Abstract: The behaviour of a nuclear core reactor can be modeled by the neutron diffusion equation. In the steady-state case, one must solve an eigenvalue problem. More precisely, one looks for the…
Title: Convergent algorithm based on Carleman estimates for the recovery of a coefficient in the wave equation. Joint works with Lucie Baudouin, Sylvain Ervedoza and Axel Osses. Abstract: We are interested in an inverse problem for the wave equation. More precisely, it consists in the determination of an unknown time-independent coefficient…