Arbres de mémoire

Grammaire de Ramanujan et arbres de Cayley

— We study three sequences of polynomials defined as successive derivatives with respect to a differential operator associated with a grammar (one of these sequences was originally introduced by Ramanujan). Combinatorial interpretations for these polynomials are found in terms of rooted trees and graphs of mappings from [n] to [n]. Introduction Dans [Ra], [B], Ramanujan (et B. Berndt à sa suite...

Arbres de Markov couple

The Hidden Markov Chain (HMC) models are widely applied in various problems. This succes is mainly due to the fact that the hidden model distribution conditional on observations remains a Markov chain distribution, and thus different processings, like Bayesian restorations, are handleable. These models have been recetly generalized to “Pairwise” Markov chains, which admit the same processing po...

Arbres et Hierarchies de Concatenation

A la mémoire de Max Wajskop

Max Wajskop, notre ami, notre collegue, directeur de l'lnstitut de Phon6tique de Bruxelles, 6diteur en Chef de Speech Communication et membre fondateur de I 'ESCA (European Speech Communication Association) est d4c6d~ le mardi 6 avril 1993. ll y a un an, accabl6 par la disparition de sa femmc Monique Hiann6, qui rut aussi sa collaboratrice pendant 30 ans, il ~tait lui-mame frappe par la maladie...

Mémoire des Sciences de la Terre