Carlitz a défini sur une fonction et une série formelle , analogues respectivement à la fonction de Riemann et au réel . Yu a montré, en utilisant les modules de Drinfeld, que est transcendant pour tout non divisible par . Nous donnons ici une preuve «automatique» de la transcendance de pour , en utilisant le théorème de Christol, Kamae, Mendès France et Rauzy.
La fonction de récurrence d’une suite symbolique compte au bout de combien de temps on voit tous les mots de longueur . Nous la calculons explicitement pour les suites d’Arnoux-Rauzy, définies par des conditions combinatoires qui en font une généralisation naturelle des suites sturmiennes. Puis nous répondons à une question de Morse et Hedlund (1940) en montrant que ne peut avoir une limite finie pour aucune suite non ultimement périodique.
In this paper methods and results related to the notion of minimal forbidden words are applied to the fragment assembly problem. The fragment assembly problem can be formulated, in its simplest form, as follows: reconstruct a word from a given set of substrings (fragments) of a word . We introduce an hypothesis involving the set of fragments and the maximal length of the minimal forbidden factors of . Such hypothesis allows us to reconstruct uniquely the word from the set in linear...
In this paper methods and results related to the notion of minimal forbidden words are applied to the fragment assembly problem. The fragment assembly problem can be formulated, in its simplest form, as follows: reconstruct a word w from a given set I of substrings (fragments) of a word w. We introduce an hypothesis involving the set of fragments I and the maximal length m(w) of the minimal forbidden factors of w. Such hypothesis allows us to reconstruct uniquely the word w from the set I in linear...
We study hybrid systems with strong resets from the perspective of formal language theory. We define a notion of hybrid regular expression and prove a Kleene-like theorem for hybrid systems. We also prove the closure of these systems under determinisation and complementation. Finally, we prove that the reachability problem is undecidable for synchronized products of hybrid systems.
Starting from late 90’s the public administration has started to employ a quite relevant amount of its budget in developing ICT solutions to better deliver services to citizens. In spite of this effort many statistics show that the mere availability of ICT based services does not guarantee per se their usage. Citizens have continued to largely access services through “traditional” means. In our study we suggest that the highlighted situation is partly due to the fact that relevant domain dependent...
Starting from late 90’s the public administration has started to employ a quite relevant amount of its budget in developing ICT solutions to better deliver services to citizens. In spite of this effort many statistics show that the mere availability of ICT based services does not guarantee per se their usage. Citizens have continued to largely access services through “traditional” means. In our study we suggest that the highlighted situation is partly...
Dans cet article, nous présentons les aspects essentiels de la modélisation du processus décisionnel des joueurs de tennis dans une phase particulière de ce jeu sportif : le service-retour. Notre démarche se focalise sur la représentation des connaissances s'exerçant dans un continuum temporel scindé en micro-cycles et sur la construction de structures permettant d'envisager l'auto-apprentissage des caractéristiques technico-tactiques des joueurs par le système. Elle s'appuie sur la mise en oeuvre...