1,722,164 research outputs found
Groupe de théorie neurale
No full textLe Groupe de théorie neuronale s’articule autour de trois chercheurs permanents (Sophie Denève, Boris Gutkin et Christian Machens) et d’un chercheur invite (M. Tsodyks). Nous utilisons des méthodes issues des mathématiques, des statistiques et de la physique pour modéliser la dynamique des processus neuronaux et leurs principes computationnels. Théorie bayesienne de la biophysique et des calculs neuronaux Nous avons développé une théorie probabiliste du codage neuronal dans le cas de neurones..
Pierre-Alban GUTKIN-GUINFOLLEAU - L’existence à l’œuvre. Philosophie de Jankélévitch
No full textPublication de : Pierre-Alban GUTKIN-GUINFOLLEAU, L'existence à l’œuvre, Paris, PUF, coll. Hors collection, novembre 2023, 312 p. L’unité d’une œuvre d’apparence éclatée se gagne dans la formulation d’un dénominateur commun à toutes ses parties. L’erreur qui consiste à voir dans la pensée de Vladimir Jankélévitch un émiettement de considérations morales sur les vertus réside dans une cécité qui suppose, pour recouvrer la vue, de comprendre cette œuvre comme une philosophie de l’existence. C..
DISSIPATIVE OUTER BILLIARDS: A CASE STUDY
Full text linkThis paper is dedicated to the memory of the third author, who unexpectedly passed away while the paper was being completed. Abstract. We study dissipative polygonal outer billiards, i.e. outer billiards about convex polygons with a contractive reflection law. We prove that dissipative outer billiards about any triangle and the square are asymptotically periodic, i.e. they have finitely many global attracting periodic orbits. A complete description of the bifurcations of the periodic orbits as the contraction rates vary is given. For the square billiard, we also show that the as-ymptotic periodic behavior is robust under small perturbations of the vertices and the contraction rates. Finally, we describe some numerical experiments suggesting that dissipative outer billiards about regular polygon are generically asymptotically periodic. 1. Introduction an
Compressive failure and kink-band formation modeling
Full text linkTo increase the use of polymeric structural composites, a major issue is to properly account for intra-laminar failure mechanisms, such as fiber kinking induced under compression. We propose a new continuum damage model that can predict the fiber kinking response at the ply level. The model is based on a previous structure tensor-based model for the response of UD-plies. A novel feature is that the compressive UD-ply response at the macroscale includes the effect of the fiber misalignment shaped as a kink-band that is resolved at the sub-scale. Concepts of computational homogenization are used to include the fiber-shear of the kink-band at the sub-scale. The model calibration is adapted to account for either kink-band formation or shear-splitting depending on the off-axis loading. Finally, the model is validated at the laminate level against experimental data for OHC-tests available in the literature. A good agreement is found for predicted strength values and observed fracture patterns of the laminates. The size effect experienced when different hole sizes are tested is also addressed
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