Archives Ouvertes HAL

Toutes les publications de l'ENAC en direct.
All ENAC publications.

[hal-01819040] The role of the Hardy type inequalities in the theory of function spaces

Publications ENAC - Wednesday, 20 June 2018 - 10:53:12
We illustrate the crucial importance of the Hardy type inequalities in the study of function spaces, especially of fractional regularity. Immediate applications include Sobolev and Morrey type embeddings, and properties of the superposition operator $f\mapsto \Phi\circ f$. Another fundamental consequence is the trace theory of weighted Sobolev spaces. In turn, weighted Sobolev spaces are useful in the regularity theory of the superposition operators. More involved applications, that we present in the final section, are related to Sobolev spaces of maps with values into manifolds.

[hal-01819013] Two-dimensional macroscopic model for large scale traffic networks

Publications ENAC - Wednesday, 20 June 2018 - 10:47:08
In this article we introduce a new traffic flow model for a dense urban area. We consider a two-dimensional conservation law in which the velocity magnitude is given by the fundamental diagram and the velocity direction is constructed following the network geometry. We validate the model using synthetic data from Aimsun and propose a reconstruction technique to recover the 2D density from the data of individual vehicles. A comparison between the model and the data is shown.

[hal-01578728] Existence of Lipschitz continuous Lyapunov functions strict outside the strong chain recurrent set

Publications ENAC - Wednesday, 20 June 2018 - 10:44:56
The aim of this paper is to study in detail the relations between strong chain recurrence for flows and Lyapunov functions. For a continuous flow on a compact metric space, uniformly Lipschitz continuous on the compact subsets of the time, we first make explicit a Lipschitz continuous Lyapunov function strict –that is strictly decreasing– outside the strong chain recurrent set of the flow. This construction extends to flows some recent advances of Fathi and Pageault in the case of homeomorphisms; moreover, it improves Conley's result about the existence of a continuous Lyapunov function strictly decreasing outside the chain recurrent set of a continuous flow. We then...

[tel-01819085] Etude du peptidome du cervelet de rat au cours du développement et identification des effets neurotrophiques de la nociceptine dans la mise en place des neurones en grain.

Publications ENAC - Wednesday, 20 June 2018 - 03:23:07
Le cervelet est une structure cérébrale impliquée dans de multiples fonctions motrices mais aussi cognitives et dont le développement postnatal est sous le contrôle de divers types de facteurs dont les neuropeptides. Les peptides capables d’agir sur le développement du cortex cérébelleux présentent généralement un profil d’expression particulier, avec chez le rongeur un pic d’expression au cours des 2 premières semaines postnatales. L’objectif de cette étude était d’identifier d’autres peptides présentant ce même type d’expression et de caractériser leurs potentiels effets au cours du développement du cortex cérébelleux, et plus particulièrement dans la mise en place des...

[tel-01819084] Adaptive optics for fluorescence correlation spectroscopy

Publications ENAC - Wednesday, 20 June 2018 - 03:01:19
This research project combines two complementary aspects: the development of an assembly incorporating an Adaptive Optics microscope system and the study of cancerous masses (multicellular spheroids) under mechanical pressure.These two axes are mutually beneficial since the implementation of the adaptive optics will enable imaging and physical measurements in spheroids; On the other hand, the study of spheroids will characterize the aberrations induced by this type of samples and understand the requirements of the adaptive optics system imposed by the observation of these samples as well as the limits of optical microscopy in biological tissues.

[tel-01816413] Exact boundary controllability and exact boundary synchronization for a coupled system of wave equations with Neumann and coupled Robin boundary controls

Publications ENAC - Tuesday, 19 June 2018 - 20:46:21
For a coupled system of wave equations, the exact boundary controllability and the exact boundary synchronization can be realized by different types of boundary controls, such as Dirichlet type, Neumann type and coupled Robin type and so on. Up to now, there are already fairly complete results for a coupled system of wave equations with Dirichlet boundary controls. Based on these results, in this thesis, we will further consider the exact boundary synchronization for a coupled system of wave equations with Neumann boundary controls and coupled Robin boundary controls. In this thesis, we firstly give a brief introduction to the history of the research of synchronization...

[hal-01818792] Comparative survey: People detection, tracking and multi-sensor Fusion in a video sequence

Publications ENAC - Tuesday, 19 June 2018 - 19:49:26
Tracking people in a video sequence is one of the fields of interest in computer vision. It has broad applications in motion capture and surveillance. However, due to the complexity of human dynamic structure, detecting and tracking are not straightforward. Consequently, different detection and tracking techniques with different applications and performance have been developed. To minimize the noise between the prediction and measurement during tracking, Kalman filter has been used as a filtering technique. At the same time, in most cases, detection and tracking results from a single sensor is not enough to detect and track a person. To avoid this problem, using a multi-...

[hal-01817281] Associations isiaques d’Occident

Publications ENAC - Tuesday, 19 June 2018 - 19:28:51
Dans cette étude, on fait le point de nos maigres connaissances sur les associations isiaques de l’Occident romain et s’attache, dans un premier temps, à l’épineux problème des pastophores qui, regroupés en collèges, auraient eu pour tâche de déployer “l’étoffe de lin sur laquelle est peinte la déesse (Isis) et tout ce qui est autour d’elleˮ mentionnée par une dédicace de Pergame, du Ier siècle p.C. (RICIS, 301/1202). L’idée est séduisante, mais cette offrande est suivie d’une autre consistant en “trois autres sindônai brillants de blancheurˮ, manifestement des vêtements rituels, comme le traduit L. B. Dans ce cas, la première étoffe pourrait aussi désigner un vêtement...

[hal-01817282] Le monnayage d’Auguste à Alexandrie

Publications ENAC - Tuesday, 19 June 2018 - 19:28:09
This paper attempts to highlight aspects of Augustan rule in Egypt through numismatic analysis. Outside of specific points regarding the number of groups that make up the Augustan issues, a central argument which emerges is that Alexandrian coinage under Augustus followed Ptolemaic precedent, while also incorporating Roman imagery and the concept of diui filius to align Augustus with Pharaonic authorizing techniques.

[hal-01818956] An inverse obstacle problem for the wave equation in a finite time domain

Publications ENAC - Tuesday, 19 June 2018 - 19:25:43
We consider an inverse obstacle problem for the acoustic transient wave equation. More precisely, we wish to reconstruct an obstacle characterized by a Dirichlet boundary condition from lateral Cauchy data given on a subpart of the boundary of the domain and over a finite interval of time. We first give a proof of uniqueness for that problem and then propose an " exterior approach " based on a mixed formulation of quasi-reversibility and a level set method in order to actually solve the problem. Some 2D numerical experiments are provided to show that our approach is effective.
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