28 Mai - 3 Juin


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Mardi 29 Mai
Heure: 11:00 - 12:00
Lieu: Salle B107, bâtiment B, Université de Villetaneuse
Résumé: (CIP) Discussion on graph rewriting systems (with examples and equations)
Description: Nicolas Behr Séminaire annulé à cause de difficultés de transport. Le séminaire de 14h00
est maintenu.
Heure: 14:00 - 16:00
Lieu: Salle B107, bâtiment B, Université de Villetaneuse
Résumé: Combinatorics of chemical reaction systems
Description: Nicolas Behr Reporting on recent work with G.H.E. Duchamp and K.A. Penson (arXiv:1712.06575), I plan to present a formulation of chemical reaction systems in the so-called stochastic mechanics formalism. This approach allows to uncover some deep relationships between the combinatorial techniques of boson normal-ordering and the dynamics of chemical reaction networks: each semi-linear reaction type induces an evolution within a space of probability distributions that can be computed explicitly via our techniques. For the interesting remaining types of reactions, some results involving systems of Sobolev-Jacobi orthogonal polynomials will be presented.
Jeudi 31 Mai
Heure: 12:15 - 13:30
Lieu: Salle B107, bâtiment B, Université de Villetaneuse
Résumé: Graphes dynamiques - Modélisation et Clustering
Description: Tabea Rebafka To model recurrent interaction events we propose a new dynamic random graph model : an extension of the stochastic block model in continuous time, where every individual (node) belongs to a latent group and interactions (edges) between two individuals are modelled using inhomogeneous Poisson processes. We develop a semiparametric variational expectation-maximization algorithm to estimate model parameters and to perform a clustering of the nodes. We illustrate the performance of our method on real datasets.