Statistical inference for the spatial dual-frequency coherence function with application in EEG functional connectivity
Catégorie d'évènement : Groupe de travail Probabilités et Statistique Date/heure : 31 mai 2018 09:15-10:15 Lieu : Oratrice ou orateur : Jean Marc Freyermuth Résumé :Sophisticated functional connections appears in experiments designed for assessing the visual working memory of the human brain. Elucidating the nature
of these interactions is supposedly a doorway for fruitful inference on brain cognitive processes. A challenging aspect is that they may involve brain waves
oscillatory components of possibly different frequencies. We develop a statistical methodology to study collections of replicated spatially localized EEG time
series. In the pursue of realistic and tractable time series models, we introduce
a new class of spatio-temporal processes that are time-harmonizable. We consider available replicates and seek for the estimation of both the spatial Loeve-
spectrum and the spatial dual-frequency coherence function. In other words we
measure a squared correlation coefficient across different frequencies between
any spatial locations. Our method exploit the spatial correlations to improve
the local estimation of the coherence between different frequency bands. We
derive the asymptotic distribution of the spatial coherence function and build
bootstrap-based confidence intervals.
This is based on joint work with John Aston, Dominique Dehay, Anna Dudek
and Denes Scusz.
Sur un algorithme d'exploration pour des jeux
Catégorie d'évènement : Séminaire Probabilités et Statistique Date/heure : 31 mai 2018 10:45-11:45 Lieu : Oratrice ou orateur : Nicolas Fournier Résumé :On essaye d’étudier une classe d’algorithmes du type Monte Carlo Tree Search pour des jeux
déterministes à trait alterné et information complète (du type morpion, puissance 4, etc.).
Weinstein's "Poisson category" in derived algebraic geometry
Catégorie d'évènement : Séminaire Théorie de Lie, Géométrie et Analyse Date/heure : 31 mai 2018 14:15-15:15 Lieu : Oratrice ou orateur : Valerio Melani Résumé :Motivated by deformation quantization, Weinstein initiated the study of the « Poisson category ». This should be a category whose objects are Poisson manifolds, and whose morphisms are coisotropic correspondences. Unfortunately, in the general case there is no such category. In fact, composition of morphisms by fiber products is not always available, and one needs to put strong enough « clean intersection » hypothesis to make it possible. In this talk, we present a realization of the Poisson category in the context of derived algebraic geometry, which is a homotopical generalization of classical algebraic geometry. The talk will be based on joint work(s) with Rune Haugseng and Pavel Safronov.
On the Jesmanowicz-Terai conjecture and pure ternary exponential Diophantine equations
Catégorie d'évènement : Séminaire de Théorie des Nombres de Nancy-Metz Date/heure : 31 mai 2018 14:30-15:30 Lieu : Oratrice ou orateur : Zhu Huilin Résumé :https://dev-iecl.univ-lorraine.fr/Les-Seminaires/Theorie-Des-Nombres/wolfcms/seminaire.html