Groupes de Ping-Pong et comptage

Décompositions de Groupes par Produit Direct et Groupes de Coxeter

We provide examples of groups which are indecomposable by direct product, and more generally which are uniquely decomposable as direct products of indecomposable groups. Examples include Coxeter groups, for which we give an alternative approach to recent results of L. Paris. For a finitely generated linear group Γ, we establish an upper bound on the number of factors of which Γ can be the direc...

Groupes de Galois et nombres automatiques

Treillis et bases des groupes de Coxeter

A Dominique Foata, pionnier de la combinatoirè a qui elle doit tant 1. Introduction. — Le présent travail est une contributionà l'´ etude de l'ordre fort (dit aussi de Bruhat) dans un groupe de Coxeter fini W. Les définitions et propriétés relatives aux treillis, aux ensembles or-donnés, aux bases et aux treillis enveloppants, &c. sont rassemblées de manì ere minimale dans la section 2, les pre...

Ping pong in the pore

Getting to the inner circle ontiguity between the ER and the nuclear envelope means nuclear membrane proteins have a direct shot to their target. In fact, inner nuclear membrane (INM) proteins were thought to need only to diffuse to the nucleus, pass through the nuclear pore, and then be retained by nuclear-localized binding partners. But new results suggest a more active process. Suraj Saksena...

Ping-Pong: Musically Discovering Locations

A recently developed system that uses pitched sounds to discover relative 3D positions of a group of devices located in a shared physical space is described. The measurements are coordinated over an IP network in a decentralized manner, while the actual measurements are carried out measuring the time-of-flight of the notes played by different devices. Approaches to sonify the discovery process ...