derniers depôts

Ajouté le 08/08/2017

We improve upon the first Thom-Mather isotopy theorem for Whitney stratified sets. In particular , for the more general Bekka stratified sets we show that there is a local foliated structure with continuously varying tangent spaces, thus proving the smooth version of the Whitney fiber-ing conjecture. A regular wing structure is also shown to exist locally, for both Whitney and Bekka stratifications. The proofs involve integrating carefully chosen controlled distributions of vector fields.

Ajouté le 08/08/2017

Le plomb est un métal exploité depuis des millénaires, mais son usage s'estaccentué avec la révolution industrielle. L'exposition de populations travaillantdans les industries utilisant le plomb a révélé les effets délétères de ce métal surdifférentes fonctions biologiques.

Ajouté le 04/08/2017

À la fin des années 1980, l’intoxication saturnine a émergé en France non plusseulement sous forme de cas isolés d’intoxication aiguë, mais comme uneforme pernicieuse d’atteinte chronique, souvent cliniquement latente, quidevait faire l’objet d’une préoccupation spécifique de la part des autorités sanitaires.En effet, lié à un toxique largement répandu dans l’environnement, aux effetscliniques difficilement décelables et à un détriment sanitaire prolongé très audelàde la soustraction à l’exposit

Ajouté le 02/08/2017

This paper highlights the limitations inherent to the stochastic earnings frontier methodology to analyzing wage discrimination and introduces the use of the metafrontier approach as an important improvement. Using US data from the Current Population Survey, we find that white women’s and black men’s maximum attainable hourly earnings represent respectively 80% and 76% of those of white men on average.

Ajouté le 02/08/2017

In this article we study the controllability properties of general compactly perturbed exactly controlled linear systems with admissible control operators. Firstly, we show that approximate and exact controllability are equivalent properties for such systems. This unifies previous results available in the literature and that were established separately so far.

Ajouté le 02/08/2017

Given a network and a set of source destination pairs (connections), we consider the problem of maximizing the sum of the flow under proportional delay constraints. In this paper, the delay for crossing a link is proportional to the total flow crossing this link. If a connection supports non-zero flow, then the sum of the delays along any path corresponding to that connection must be lower than a given bound.

Ajouté le 01/08/2017

Port Hamiltonian systems (PHS) are open passive systems that full a power balance: they correspond to dynamical systems composed of energy-storing elements, energy-dissipating elements and external ports, endowed with a geometric structure (called Dirac structure) that encodes conservative interconnections. This paper presents a minimal PHS model of the full vocal apparatus.

Ajouté le 02/08/2017

L'économétrie et l'apprentissage machine semblent avoir une finalité en commun: construire un modèle prédictif, pour une variable d'intérêt, à l'aide de variables explicatives (ou features). Pourtant, ces deux champs se sont développés en parallèle, créant ainsi deux cultures différentes, pour paraphraser Breiman (2001a). Le premier visait à construire des modèles probabilistes permettant de décrire des phénomèmes économiques.

Ajouté le 01/08/2017

In this article we study the case of an autonomous motor-glider. The aims of the aircraft is to maintain its flight as long as possible, taking advantage of the rising air from the ground, known as thermals, despite of limited energy resources and possible external influences, such as turbulences. The pilot task being to make decisions with incomplete, uncertain or even contradictory information, as well as driving to the desired path or destination.

Ajouté le 30/07/2017

We investigate the local structure of nanoparticles based on a manganese ferrite core surrounded or not by a maghemite layer obtained after hydrothermal surface treatment.

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