Techniques neuronales et fusion de données appliquées à un système de détection de passage de véhicules "en-ligne"

Nous présentons ici un système temps réel de détection de passage de véhicules au dessus de capteurs magnétiques. Le système est indépendant du positionnement initial des capteurs et insensible aux perturbations magnétiques fortes éventuellement induites par les charges des véhicules. Ce système est fondé sur la coopération d'agents de détection neuronaux, avec une mesure de fiabilité de leurs réponses, et une fusion des informations de chaque agent par des règles logiques. Le système est robuste à de fortes perturbations magnétiques (y compris non-périodiques), il utilise les 3 composantes du champ magnétique, il est insensible aux rotations, et la modularité de sa conception permet une grande évolutivité

Integrable systems without the Painlev\'e property

We examine whether the Painlev\'e property is a necessary condition for the integrability of nonlinear ordinary differential equations. We show that for a large class of linearisable systems this is not the case. In the discrete domain, we investigate whether the singularity confinement property is satisfied for the discrete analogues of the non-Painlev\'e continuous linearisable systems. We find that while these discrete systems are themselves linearisable, they possess nonconfined singularities

On positive solutions and the Omega limit set for a class of delay differential equations

This paper studies the positive solutions of a class of delay differential equations with two delays. These equations originate from the modeling of hematopoietic cell populations. We give a sufficient condition on the initial function for $t\leq 0$ such that the solution is positive for all time $t>0$. The condition is "optimal". We also discuss the long time behavior of these positive solutions through a dynamical system on the space of continuous functions. We give a characteristic description of the $\omega$ limit set of this dynamical system, which can provide informations about the long time behavior of positive solutions of the delay differential equation.Comment: 15 pages, 2 figure

A list of all integrable 2D homogeneous polynomial potentials with a polynomial integral of order at most 4 in the momenta

We searched integrable 2D homogeneous polynomial potential with a polynomial first integral by using the so-called direct method of searching for first integrals. We proved that there exist no polynomial first integrals which are genuinely cubic or quartic in the momenta if the degree of homogeneous polynomial potentials is greater than 4.Comment: 22 pages, no figures, to appear in J. Phys. A: Math. Ge

Transformée en ondelettes et modèles de Markov cachés pour la segmentation automatique du signal ECG

- Cette article présente une approche de segmentation automatique du signal ECG qui utilise la transformée en ondelettes et les modèles de Markov cachés (MMC). Le modèle MMC est la concaténation des modèles markoviens élémentaires de chaque onde P, QRS et T d'un battement cardiaque, permettant la détection de toutes ces ondes dans un signal ECG. Malgré la faible taille du corpus d'apprentissage, le MMC proposé montre une très bonne précision dans la segmentation des différents battements, comparée à 1 méthode classique. Le MMC a le grand avantage de s'adapter aux variations du signal ECG et surtout de faire de manière conjointe la détection du battement cardiaque et sa segmentation en ondes P, QRS et T

On the Floquet Theory of Delay Differential Equations

We present an analytical approach to deal with nonlinear delay differential equations close to instabilities of time periodic reference states. To this end we start with approximately determining such reference states by extending the Poincar'e Lindstedt and the Shohat expansions which were originally developed for ordinary differential equations. Then we systematically elaborate a linear stability analysis around a time periodic reference state. This allows to approximately calculate the Floquet eigenvalues and their corresponding eigensolutions by using matrix valued continued fractions

Fingerprint and On-Line Signature Verification Competitions at ICB 2009

This paper describes the objectives, the tasks proposed to the participants and the associated protocols in terms of database and assessment tools of two competitions on fingerprints and on-line signatures. The particularity of the fingerprint competition is to be an on-line competition, for evaluation of fingerprint verification tools such as minutiae extractors and matchers as well as complete systems. This competition will be officialy launched during the ICB conference. The on-line signature competition will test the influence of multi-sessions, environmental conditions (still and mobility) and signature complexity on the performance of complete systems using two datasets extracted from the BioSecure database. Its result will be presented during the ICB conference