Vieira, Alexandre Brogliato, Bernard Prieur, Christophe

This article is dedicated to the analysis of quadratic optimal control of linear complementarity systems (LCS), which are a class of strongly nonlinear and nonsmooth dynamical systems. Necessary first-order conditions are derived, that take the form of an LCS with inequality constraints, hence are numerically tractable. Then two numerical solvers a...

Nataf, F.

Convergence of domain decomposition methods rely heavily on the efficiency of the coarse space used in the second level. The GenEO coarse space has been shown to lead to a fully robust two-level Schwarz preconditioner which scales well over multiple cores [27, 19] as has been proved rigorously in [27]. The robustness is due to its good approximatio...

Papež, Jan Rüde, Ulrich Vohralík, Martin Wohlmuth, Barbara

We derive guaranteed, fully computable, constant-free, and sharp upper and lower a posteriori estimates on the algebraic, total, and discretization errors of finite element approximations of the Poisson equation obtained by an arbitrary iterative solver. The estimators are computed locally over patches of mesh elements around vertices and are based...

Nicolopoulos, Anouk Campos Pinto, Martin Després, Bruno

We consider a boundary value problem (BVP) for a reduced system of time harmonic Maxwell equations in magnetized plasma. The dielectric tensor is strongly anisotropic and the system admits resonant solutions in the context of the limit absorption principle. In particular, in the vanishing viscosity limit the normal component of the electric field b...

Ahmed, Elyes Ali Hassan, Sarah Japhet, Caroline Kern, Michel Vohralík, Martin

We consider two-phase flow in a porous medium composed of two different rock types, so that the capillary pressure field is discontinuous at the interface between the rocks. This is a nonlinear and degenerate parabolic problem with nonlinear and discontinuous transmission conditions on the interface. We first describe a space-time domain decomposit...

Duprez, Michel Morancey, Morgan Rossi, Francesco

In this work, we study the minimal time to steer a crowd to a desired configuration. The control is a vector field, representing a perturbation of the crowd displacement, localized on a fixed control set. We give a characterization of the minimal time both for discrete and continuous crowds. We show that the minimal time to steer one initial config...

Abergel, Rémy Moisan, Lionel

We propose a computational procedure to evaluate the generalized incompletegamma function ∫_{x}^{y} s^{p-1} e^{-μs} ds, for0 ≤ x

Essadki, Mohamed Drui, Florence Chaisemartin, Stéphane Larat, Adam Ménard, Thibault Massot, Marc

In this work, we investigate an original strategy in order to derive a statistical modeling of the interface in gas-liquid two-phase flows through geometrical variables. The contribution is twofold. First it participates in the theoretical design of a unified reduced-order model for the description of two regimes: a disperse phase in a carrier flui...

Mourrain, Bernard Telen, Simon Van Barel, Marc

We consider the problem of finding the isolated common roots of a set of polynomial functions defining a zero-dimensional ideal I in a ring R of polynomials over C. Normal form algorithms provide an algebraic approach to solve this problem. We use new characterizations of normal forms and describe accurate and efficient constructions that allow us ...

Burman, Erik Fernández, Miguel Angel Frei, Stefan

We derive a Nitsche-based formulation for fluid-structure interaction (FSI) problems with contact. The approach is based on the work of Chouly and Hild [SIAM Journal on Numerical Analysis. 2013;51(2):1295–1307] for contact problems in solid mechanics. We present two numerical approaches, both of them formulating the FSI interface and the contact co...