Search results for "ALGORITHME"
showing 10 items of 36 documents
Un algorithme de gestion de collision efficace pour un NoC déployé sur multi-FPGA
2014
International audience; Les plateformes multi-FPGA sont les solutions les plus prometteuses pour l'émulation de MPSoCs (Multi-Processor System-on-Chip) à base de NoC (Network-on-Chip). Le déploiement d'un NoC de grande taille sur une plateforme multi-FPGA nécessite la mise en place d'interfaces pour la communication inter-FPGA. Des goulots d'étranglements apparaissent, ralentissant fortement les performances du système. Dans ce travail, nous proposons un algorithme de gestion de collision permettant de supprimer ces goulots d'étranglement. L'algorithme de gestion de collision est basé sur l'algorithme de backoff utilisé dans les réseaux informatiques. L'architecture proposée est constituée …
Traitement 3D de nuages de points basé sur la connaissance
2013
The modeling of real-world scenes through capturing 3D digital data has proven to be both useful andapplicable in a variety of industrial and surveying applications. Entire scenes are generally capturedby laser scanners and represented by large unorganized point clouds possibly along with additionalphotogrammetric data. A typical challenge in processing such point clouds and data lies in detectingand classifying objects that are present in the scene. In addition to the presence of noise, occlusionsand missing data, such tasks are often hindered by the irregularity of the capturing conditions bothwithin the same dataset and from one data set to another. Given the complexity of the underlying…
'SMART laser', Development of laser sources integrating an optimized functioning via a process of learning
2022
Ost commercially available mode-blocking lasers provide a unique pulse regime to the user, driven only by a simple switch. To solve certain problems, it would be advantageous to increase the possibilities of pulse adjustment in many areas of application, from micro-machining to wavelength conversion. One way to increase the degrees of freedom of a laser cavity is to incorporate into it a saturable absorbant with adjustable parameters, as with non-linear polarization evolution devices (NPEs). The absence of an analytical relationship between the adjustable cavity parameters and the characteristics of a generated pulse can be circumvented by the use of scalable algorithms, well suited to mult…
Evolutionary algorithm for fiber laser in ultrashort pulse regime
2016
This thesis deals with the generation of ultrashort pulses within a fiber laser cavity through the automatic optimization of its parameters by an evolutionary algorithm. The interest of this subject comes from the difficulty to systematically explore dynamics in a large domain of experimental parameters. We have shown that it is possible to implement an evolutionary algorithm on fiber laser cavity with appropriate precautions. We have experimentally demonstrated for the first time the mode locking of a laser cavity only using the optimization of polarization controllers through an automatic and self-learning procedure. We also have demonstrated that selecting the mode locking from it radio-…
Contribution à l'étude de la formation des images optiques en microscopie champ proche optique: effet de la sonde en deux dimensions
2004
This work consists in the development of a theoretical tool for the purpose to undertake numerical simulations able to take into account the coupling between the probe and the object. The first part, concerns the combination of the differential method and the algorithms T and S, to overcome numerical problems which appear in the cases where the size of system (probe - object) is more realistic. The developed global model is two-dimensional and applied in polarization TE under the normal diffraction condition. We have used the developed model to study the formation of optical image by monomodes and multimodes probes. The obtained optical images at constant height, have allowed us to study th…
A simple algorithm to estimate evapotranspiration from DAIS data: Application to the DAISEX campaigns
2005
DOI:10.1016/j.jhydrol.2005.03.027; The knowledge of evapotranspiration is of great interest in many applications such as assessing irrigation water use. In this paper, a methodology is presented to estimate evapotranspiration using the surface energy balance model S-SEBI (Simplified Surface Energy Balance Index) and the evaporative fraction. The method is applicable under the assumptions of constant atmospheric conditions and sufficient wet and dry pixels over the image. The model uses remotely sensed parameters such as albedo, MSAVI (Modified Soil Adjusted Vegetation Index) and surface temperature and emissivity images. The methodology has been applied over the Barrax test site, located in…
CAMLearn : a semantic context-aware recommender system architecture : application on m-learning domain
2015
Given the rapid emergence of new mobile technologies and the growth of needs of a moving society in training, works are increasing to identify new relevant educational platforms to improve distant learning. The next step in distance learning is porting e-learning to mobile systems. This is called m-learning. So far, learning environment was either defined by an educational setting, or imposed by the educational content. In our approach, in m-learning, we change the paradigm where the system recommends content and adapts learning follow to learner's context.
Developement of new techniques of Optimal Control in Quantum Dynamics : from nuclear magnetic resonance to molecular physics
2011
The goal of this thesis is to apply the optimal control theory to the dynamics of quantum systems.The first part aim at introducing the tools of optimal control in quantum control which were initially developedin mathematics. This approch has been applied on different kinds of quantum system with small and largedimensions. The first part of this manuscript introduces the optimal control tools which are used with a pointof view suited to a public of physicists. In the second part these techniques are used to control the dynamics ofspins in NMR and MRI. The third part deals with the development of new iterative algorithms applied to thecontrol by laser fields of the rotational dynamics of lin…
Stochastic algorithms for robust statistics in high dimension
2016
This thesis focus on stochastic algorithms in high dimension as well as their application in robust statistics. In what follows, the expression high dimension may be used when the the size of the studied sample is large or when the variables we consider take values in high dimensional spaces (not necessarily finite). In order to analyze these kind of data, it can be interesting to consider algorithms which are fast, which do not need to store all the data, and which allow to update easily the estimates. In large sample of high dimensional data, outliers detection is often complicated. Nevertheless, these outliers, even if they are not many, can strongly disturb simple indicators like the me…
Une approche Web sémantique et combinatoire pour un système de recommandation sensible au contexte appliqué à l'apprentissage mobile
2014
National audience; Au vu de l'émergence rapide des nouvelles technologies mobiles et la croissance des offres et besoins d'une société en mouvement en formation, les travaux se multiplient pour identifier de nouvelles plateformes d'apprentissage pertinentes afin d'améliorer et faciliter le processus d'apprentissage à distance. La prochaine étape de l'apprentissage à distance est naturellement le port de l'e-learning (apprentissage électronique) vers les nouveaux systèmes mobiles. On parle alors de m-learning (apprentissage mobile). La recherche d'informations dans le domaine du m-learning peut être définie comme une activité dont la fi-nalité est de localiser et de délivrer des contenus d'a…