Éditeur(s) : HAL CCSD
Résumé : National audience
ORASIS Proceedings

hal-00634755
https://hal.archives-ouvertes.fr/hal-00634755

Éditeur(s) : HAL CCSD
Résumé : International audience
The Geographical Information Sciences

hal-01313379
https://hal.archives-ouvertes.fr/hal-01313379

Éditeur(s) : HAL CCSD
Résumé : International audience
This paper deals with texture classification using a multifractal approach. More precisely we analyse the singularity/regularity exponent that compose the textures because they theoretically carry most of the information. The analysis is made using the Legendre spectrum. Then a parameter vector is computed to describe this spectrum in order to classify the textures with an unsupervised k-means classifier. The resulting algorithm is evaluated against a classification directly based on the textures.
CAS Proceedings
GOSIER, France

hal-00634750
https://hal.archives-ouvertes.fr/hal-00634750

Éditeur(s) : HAL CCSD
Résumé : Half-way between optimization and astronautic, this research study deals with satellites constel- lations design problems. In order to find the required number of satellites and to correctly set their position, such are the technical challenges of this thesis. To minimise the cost and reduce the time such are the economical challenges the space industries are confronted in a daily manner. The major difficulties of these problems are the size and the characteristics of the search space The irregularity of the criterions The mathematical and physical heterogeneity of parameters forbids the use of classical algorithms The evaluation of a solution, which uses a time consuming evalua- tion without returning pertinent information about the good or bad properties of the constellations, forbid a massive exploration of the search space. From this constatation and several preliminary studies a new approach is born. Based on a better use of the simulation and on a simplification of the criterions, the algorithm is composed of several levels and uses different optimization techniques it integrates a knowledge database on the orbits and a numerical optimization process both orchestrated by a metaheuristic algorithm. This new approach tries to bypass the main drawbacks of the field with a decomposition of the problem.
A mi-chemin entre l optimisation et l astronautique ce travail de recherche s attaque au problème du design de constellations de satellites Déterminer le nombre de satellites nécessaires pour ré- pondre à un besoin et les positionner de manière correcte tels sont les enjeux techniques de cette thèse Minimiser les coûts et les délais tels sont les enjeux économiques auxquels est confronté le domaine spatial au quotidien Les difficultés majeures de ce problème sont d une part la taille et les caractéristiques de l espace de recherche; D autre part la non-régularité des critères utilisés et la nature mathématique et phy- sique hétérogène de l ensemble des paramètres (paramètres entiers et paramètres réels) interdisant l utilisation d algorithmes classiques; Enfin l évaluation des solutions qui met en oeuvre une simu- lation coûteuse en temps et en calculs sans retourner d information pertinente sur les bonnes ou mauvaises propriétés de la constellation évaluée interdit une exploration massive de l espace de recherche De ces constatations et de diverses études préliminaires est née une nouvelle approche Basé sur une meilleure exploitation de la simulation et sur une simplification des critères utilisés l algorithme composé de plusieurs niveaux met en oeuvre plusieurs techniques d optimisation En intégrant une base de connaissance sur les orbites et une méthode numérique de recherche d optimum le tout or- chestré par un algorithme métaheuristique cette nouvelle approche tente de résoudre les difficultés intrinsèques au domaine d application en décomposant le problème.
https://tel.archives-ouvertes.fr/tel-00634769

tel-00634769
https://tel.archives-ouvertes.fr/tel-00634769
https://tel.archives-ouvertes.fr/tel-00634769/document
https://tel.archives-ouvertes.fr/tel-00634769/file/grandchamp_phd_2001.pdf

Éditeur(s) : HAL CCSD
Résumé : International audience
Agrehtonmrwfsohptaeeleilmbxao.tfngioNcitfnhotsehwiaegtnchteoohdcnfyesststhaoaenrwlredsayepc.tstiaohcmcneodsoxots.pneilqIdgunei,fosfatnicms,htafoelnatysuppnsataccithmee-nlshzgiynteaotselhmwgosiesrwak,thenteelgritscoseogpxmaetcsephio-sroyevn:detsewoaimfnustonabrilqdkdcueueamcbsiaontugemtlbochittraeei.nssaWtzneehdlitoahmftbioehrnset. bsaTpTelrhgaeorsbcyv hintpi.choaerdmWsoetflhvaseclasrtetoohlubpeitesewtmahcpuoonlresso,twxceolienmaddstatitoechnldatedceimrtosiniegecnuposloiinstnsugchoaemincbrpgollandecxsurkticteb-bleachtoxaenuoc.snevFiatoelfrudtohtnheiolnserizxadefpslontfro,satahlpiuenotyoxmsinpnplagoocrseadittbyiooleniarmtsnipmspaolclizufezy,ttiiohhtnees. Trfhstoehlaueatiolcgnle.r iTtrhsmtep.larespnatsrtheotwrsmainolvegryaienwdothfemordesluintg.sOtenpocfnthleupsironblwem.prSescontdlhywpetraslpkeacbtiovuest I2fAnlSoawrdtT.eeleitrtoemdisriindveeo tnlheedgobpyytismaixnzoadtriboinmtaploropdcaeerslmaitentdgi rsesr[t1ne2t]pSleavtl=sw(ae;edic;o!mp o;sMe)awchnicdiaarteesospluetcitoinve
MIC Proceedings
Porto, Portugal

hal-00634751
https://hal.archives-ouvertes.fr/hal-00634751

Éditeur(s) : HAL CCSD
Résumé : International audience
This paper presents some considerations about hybrid optimization algorithms useful to optimize real complex system. The given indication could be used by readers to conceive hybrid algorithms. These considerations have been deducted from a concrete application case: the satellites constellations design problem. But each of the advanced techniques proposed in this paper are considered in a more general way to solve other problems. This problem is used to illustrate the techniques along the paper because it is grouping many characteristics (di culties) of contemporary real complex systems: the size and the characteristics of the search space engendered by a combinatorial problem; The irregularity of the criterions; The mathematical and physical heterogeneity of parameters forbids the use of classical algorithms; The evaluation of a solution, which uses a time consuming simulation; A need of accurate values. More details are available in previous papers ([?], [?], [?], [?]). For these reasons, we could learn a lot from this experiment in order to detach hybrid techniques usable for problems having close characteristics. This paper presents the historic leading to the current algorithm, the modeling of the complex system and the sophisticated algorithm proposed to optimize it. Application cases and ways to built signi cant tests of hybrid algorithm are also given.
HPCSE Proceedings
Toulouse, France

hal-00602264
https://hal.archives-ouvertes.fr/hal-00602264

Éditeur(s) : HAL CCSD
Résumé : International audience
Progress in Pattern Recognition, Image Analysis, Computer Vision, and Applications Lecture Notes in Computer Science

hal-00855088
https://hal.archives-ouvertes.fr/hal-00855088

Éditeur(s) : HAL CCSD
Résumé : International audience
Les écosystèmes forestiers des Caraïbes

hal-00634757
https://hal.archives-ouvertes.fr/hal-00634757

Éditeur(s) : HAL CCSD
Résumé : International audience
This paper introduces the information criteria in feature selection framework. Information criteria are integrated in feature selection scheme to select subset candidates. The accuracy of the proposed approach is based on the quality of the probability density approximations of these features. They are obtained using histograms optimized thanks to the adaptive arithmetic coding principles. Tests on simulated data and references are made. Multiple classifiers are used. The correct classification rate shows, the importance of this tools and its ability to select a best subsets. Generally, the subsets produce a good characterization of classes which the data belong.
TAIMA Proceedings

hal-00634754
https://hal.archives-ouvertes.fr/hal-00634754

Éditeur(s) : HAL CCSD
Résumé : National audience
Cet article s'intéresse à la notion de compétences et à leur processus de validation en présentant les pistes de réflexion pour la mise en place d'une interface adaptée à la fois à l'apprenant, qui souhaite démontrer l'acquisition de compétences en construisant de manière personnalisée son Dossier Numérique de Compétence (DNC), et au tuteur devant valider celles-ci, en lui présentant une synthèse automatique du parcours de l'apprenant et des compétences abordées.
IHM'14, 26e conférence francophone sur l'Interaction Homme-Machine
Lille, France

Droits : info:eu-repo/semantics/OpenAccess
hal-01089620
https://hal.archives-ouvertes.fr/hal-01089620
https://hal.archives-ouvertes.fr/hal-01089620/document
https://hal.archives-ouvertes.fr/hal-01089620/file/p24-combette.pdf

Éditeur(s) : HAL CCSD
Résumé : International audience
Pattern Recognition Letters Journal

hal-00602280
https://hal.archives-ouvertes.fr/hal-00602280

Éditeur(s) : HAL CCSD
Résumé : International audience
During the last decade, GIS have suffered of the lack of structured information and semantic definition of the data. The numerous origins of the data and the spatial localization of the object inferred many inconsistencies among them. Indeed, the way to collect data and the level of sampling of the boundary differ from one application to another and from one expert to another. This leads to different representations of the same reality and different models of semantically identical objects or boundaries. To allow the matching of the objects, or parts of the objects, when combining different information layers we introduced a conceptual layer which described a scene with concepts and spatial relationships based on the definition of an ontology. This layer allows detecting and solving conflicts between the common boundaries of two objects. We present in this paper the specification and the way to build and use the ontology.
Geoprocessing proceedings
Gosier, Guadeloupe

hal-00602257
https://hal.archives-ouvertes.fr/hal-00602257

Éditeur(s) : HAL CCSD
Résumé : International audience
IGARSS
Québec, Canada

hal-01313385
https://hal.archives-ouvertes.fr/hal-01313385

Éditeur(s) : HAL CCSD
Résumé : International audience
ISSN: 0974875X

hal-01313378
https://hal.archives-ouvertes.fr/hal-01313378

Éditeur(s) : HAL CCSD Lavoisier
Résumé : National audience
ISSN: 0765-0019

hal-00509496
https://hal.archives-ouvertes.fr/hal-00509496

Éditeur(s) : HAL CCSD
Résumé : International audience
IGARSS Proceedings

hal-00509492
https://hal.archives-ouvertes.fr/hal-00509492

Éditeur(s) : HAL CCSD
Résumé : International audience
CAS
barbades, Barbados

hal-01313388
https://hal.archives-ouvertes.fr/hal-01313388

Éditeur(s) : HAL CCSD
Résumé : International audience
ICPRAM
Rome, Italy

hal-01313380
https://hal.archives-ouvertes.fr/hal-01313380

Éditeur(s) : HAL CCSD
Résumé : International audience
The method we propose is a new approach to the problem of extbf{satellite constellation design}. The main difficulties of this field are the size of the solution space, the computation time of the optimization criterion and the lack of information to analyse and improve a solution. Our model bypasses some of these obstacles by using an extbf{inverse approach} where services to be fulfilled are highlighted. The algorithm is composed of different layers solving different problems. We first use the specifications of the services to compensate for lack of information returned by the criterion to analyse and improve a solution. An orbit database introduces an expert knowledge linked to a robust estimator to set consistent orbital parameters. We use a partial evaluation of the constellation to reduce the criterion computation time. The highest level of the algorithm is a metaheuristic layer that drives the search across the wide solution space with a probabilistic tabu search.
ICAI Proceeding

hal-00634752
https://hal.archives-ouvertes.fr/hal-00634752

Éditeur(s) : HAL CCSD
Résumé : International audience
This paper deals with image processing. This study takes place in a segmentation process based on texture analysis. We use the multifractal ap-proach to characterize the textures. More precisely we study a particular multi-fractal spectrum called the large deviation spectrum. We consider two statistical methods to numerically compute this spectrum. The resulting spectrum, com-puted by both methods over an image, is a one dimension spectrum. In the scope of this article, we extend these methods in order to obtain a two dimen-sions spectrum which could be assimilated to an image. This 2D spectrum al-lows a local characterization of the image singularities while a 1D spectrum is a global characterization. Moreover, the computation of the spectrum requires the use of a measure. We introduce here a pre processing based on the gradient to improve the measure. We show results on both synthetic and real world images. Finally, we remark that the resulting 2D spectrum is close to the resulting im-age of an edge detection process while edge detection using one dimension spectrum requires post processing methods. This statement will be used for fu-ture works.
SITIS Proceedings
Hammamet, Tunisia

hal-00602273
https://hal.archives-ouvertes.fr/hal-00602273