Équipe CASYS - IMAGES


Accueil Membres Séminaire Stages et thèses Publications Logiciels
Images

Computation of a polytopic invariant for a polynomial dynamical system (here a Phytoplankton growth model); the invariant is computed using linear programing relaxations of polynomial optimization problems based on the blossoming principle and properties of multi-affine maps.
Référence : Antoine Girard
Chains of touching beads form a class of spatially discrete nonlinear systems, with nonlinearity originating from Hertzian contact between beads. Such systems can sustain localized propagating waves (solitary waves or breathers) forming typically after an impact. The picture illustrates a propagating localized wave in a system of this type: Newton's cradle (gray levels indicate energy density versus time and space). This wave corresponds to a ``boomeron'', i.e. a localized wave displaying spontaneous direction-reversal in a spatially homogeneous nonlinear system. This origin of this intringuing dynamical behavior and its potential usefulness for the design of shock reflectors are currently under investigation.
Référence : Guillaume James
Gasip is an algorithm to simulate the gravitational interaction of point masses. This problem is known as the n-body problem in physics and astronomy. The algorithm detects and uses hierarchical structure present in the momentary distribution of the point masses to speed up the computation. The structure is represented as a dynamical tree, with the leaves being the individual point masses.
Référence : Aude Maignan
Example of algebraic graph transformation applied to cloud computing: a transformation is made of a left-hand side L, a right-hand side R, and an intermediate graph K. In this example we use the algebraic approach known as "sesqui-pushout" in order to duplicate a virtual machine; we generalize this approach for dealing with attributes: for instance the size of a virtual or real machine is a constant attribute, while the free space on a real machine is a varying attribute.
Référence : Dominique Duval
Efficiently and reliably delegating computations. The idea is to design algorithms that can form a proof of correctness of a result computed via a probabilistic algorithm or through a potentially unreliable computing center. The difficulty is to design proofs that are verifiable at a lower cost (time, memory, ...) than that of recomputing the result.
Référence : Jean-Guillaume Dumas
Illustration de l'utilisation de modèles symboliques pour le contrôle de systèmes hybrides
Référence : Antoine Girard
Algorithme de triangularisation parallèle par blocs.
Contact : Jean-Guillaume Dumas
Contrôle hybride de systèmes dynamiques non linéaires.
Contact : Aude Rondepierre
Attaques laser sur RSA embarqué ; nombres premiers à distance de perturbation d'un modulo RSA.
Contact : Jean-Guillaume Dumas
Corps finis et poésie des troubadours du XIIe siècle.
Contact : Jean-Guillaume Dumas
Modélisation hybride de l'opéron lactose.
Contact : Laurent Tournier
Optimisation de la consommation énergétique lors du transfert orbital.
Contact : Aude Rondepierre
Résolution exacte de systèmes linéaires.
Contact : Jean-Guillaume Dumas
Reconnaissance de motifs dans l'ADN par chaines de Markov puis reconstruction rationnelle bivariée
Contact : Jean-Guillaume Dumas
Calcul des états atteignables d'un système hybride.
Référence : Antoine Girard
Multiplication de matrices rapide en place.
Contact : Brice Boyer
Élimination creuse.
Contact : Jean-Guillaume Dumas