Tag: Team seminar
Éléments minimaux des régions de Shi
summary: L'arrangement de Shi, introduit en 1987 par J.-Y. Shi, est un arrangement d'hyperplans liés aux groupes de réflexions cristallographiques possédant de nombreuses propriétés intéressantes. En particulier, les régions définies par les hyperplans liés à un groupe W correspondent aux états d'un automate introduit par B ...
(q,t)-symmetry in triangular partitions
summary: The study of Dyck paths and parking functions combinatorics is a central piece of the Diagonal Harmonic Polynomials theory. It is the origin of many currents problems of algebraic combinatorics. Interactioncs between Dyck paths, parking functions, the Tamari lattice, symmetric functions and other fields of mathematics or physics have ...
Designing truthful mecanism
summary: In this presentation, we will focus on the generalization of knapsack budgeting. Given a set of projects and a budget, each voter selects a subset of projects; we want to maximize social welfare. Different measures can describe this (maximizing the minimum utility of the players, maximizing the sum of ...
Classification of truth revealing social choice algorithms
summary: The talk will be on the field of social choices. A group of players want to choose a subset of a set of objects respecting some properties (maximal weight of the subset, maximal amount of objects in the subset, ...). To do so, they vote and use a social choice ...
Block gluing in Hom shifts and path reconfiguration in graphs
summary: We study some tilings spaces that are defined from graph homomorphisms, called Hom shifts. Compared to general tiling spaces, they look the same in every direction (invariance by rotation and symmetry) and many undecidable problems or questions in tiling spaces seem to become easier for these objects, using graph-theoretical ...
Acyclic colorings of graphs and the probabilistic method
summary: Graph colorings have been extensively studied for the past century, due to the richness of the theory and its numerous applications. Part of the current research focuses on constrained colorings, and how their properties differ from proper colorings. When we require that, in a proper coloring, no (even) cycle ...
Tiling Groups: Emptiness and Aperiodicity
summary: Tilings of the plane or infinite grid have been a rich field of study for many years. Through tiling with local rules, it is even possible to create aperiodicity and embed computation in the plane. But what happens when we begin changing the underlying structure? We will explore how ...
Vingt mille lieues sous les mots
summary: Dans cette présentation, nous découvrirons une partie de l'écosystème de l'océan de la combinatoire de mots, dont l'exploration a commencé depuis plus d'un siècle. À la surface vivent d'abord les mots périodiques, aux propriétés très régulières et simples : ils nous serviront de point d ...
Introduction à l'apprentissage par renforcement
summary: Cet exposé proposera une introduction à l'apprentissage par renfocement, en présentant les fonctions à maximiser et les types d'approches employées. La présentation suivra l'évolution historique du domaine, du Q-Learning au Deep Reinforcement Learning, en passant par des travaux étant devenus populaires tel que AlphaGo. Nous conclurons ...
Strong local rules without labels for Penrose rhombus tilings
summary: The Penrose rhombus tilings are a subshift of tilings of the planefirst defined by R. Penrose. This subshift is crucial in the study of geometrical tilings because, though it was originally defined with 2 rhombus tiles with cuts-and-notches or arrows on the edges, it is an aperiodic subshift with ...