OBJETS SIMILAIRES DE GRANDE TAILLE DANS LES BASES DE DONNEES

LE BUT DE NOTRE RECHERCHE EST D'ABORDER LES PROBLEMES DE VERSIONS D'OBJETS DE GRANDE TAILLE DANS LES BASES DE DONNEES. LES IMAGES SONT DES OBJETS DE GRANDE TAILLE, FAIBLEMENT STRUCTURES, QU'IL EST POSSIBLE D'ORGANISER PAR DES STRUCTURES TELLES QUE L'ARBRE QUATERNAIRE. EN TRAITEMENT D'IMAGES, LES UTILISATEURS ONT BESOIN DE CONSERVER DIFFERENTS ETATS D'UNE MEME IMAGE, CHAQUE ETAT CORRESPONDANT AU RESULTAT D'UNE OPERATION OU D'UNE SERIE D'OPERATIONS PARTICULIERES SUR L'IMAGE. CES ETATS PEUVENT ETRE CONSIDERES COMME DES VERSIONS D'IMAGES. NOUS PROPOSONS UNE STRUCTURE, L'ARBRE QUATERNAIRE GENERIQUE, QUI STOCKE DES IMAGES SIMILAIRES, LA SIMILARITE ETANT DEFINIE PAR UNE DISTANCE ENTRE LES ARBRES QUATERNAIRES REPRESENTANT LES IMAGES. DEUX IMAGES SONT SIMILAIRES SI LEURS ARBRES QUATERNAIRES DIFFERENT SEULEMENT SUR UN NOMBRE RELATIVEMENT FAIBLE DE NUDS. L'ARBRE QUATERNAIRE GENERIQUE MINIMISE L'ESPACE DE STOCKAGE, PAR PARTAGE DE PARTIES COMMUNES ENTRE IMAGES, ET PERMET D'APPLIQUER DES OPERATIONS SUR LES IMAGES, COMME LA COMPARAISON D'IMAGES, LA COMPARAISON D'UNE MEME REGION DANS DIFFERENTES IMAGES OU LA MISE A JOUR SIMULTANEE DE DIFFERENTES IMAGES. LES OBJETS DE GRANDE TAILLE, FORTEMENT STRUCTURES, SE TROUVENT NATURELLEMENT DANS LES SGBDOO, LORS DE LA MANIPULATION DE RACINES DE PERSISTANCE (ENSEMBLE D'IDENTIFICATEURS D'OBJETS), PAR EXEMPLE. NOS TRAVAUX PERMETTENT EGALEMENT DE REPONDRE AUX PROBLEMES DE REDONDANCE LORS DU STOCKAGE DES VERSIONS D'ENSEMBLE OU DE COLLECTION D'OBJETS. CES OBJETS DE GRANDE TAILLE SONT GERES LE PLUS SOUVENT A L'AIDE DE STRUCTURES D'INDEX COMME LES ARBRES B+. NOUS PROPOSONS DES MECANISMES DE GESTION DE VERSIONS D'ARBRE B+ POUR OPTIMISER LA GESTION DE VERSIONS DE COLLECTION D'OBJETS. LES MECANISMES PROPOSES DANS CETTE THESE PEUVENT ETRE GENERALISES AUX STRUCTURES D'INDEX ARBORESCENTES EN GENERAL, OFFRANT PAR CONSEQUENT UN LARGE DOMAINE D'APPLICATIONS COUVRANT EN PARTICULIER LES SYSTEMES D'INFORMATIONS GEOGRAPHIQUES ET LES ENTREPOTS DE DONNEES.PARIS-DAUPHINE-BU (751162101) / SudocSudocFranceF

A Generalized Metric Distance between Hierarchically Partitioned Images

This article presents a generalized metric distance, called $\Delta$-distance, between images represented by a tree structure resulting from a recursive image partition. This distance is used to perform content-based image retrieval queries in databases. Delta-distance allows to retrieve images globally similar to a query image. This distance takes into account the location of the image visual features. It can be performed using a multi-level filtering algorithm. Moreover, Delta-distance allows region-based queries. In this case, the resulting images contain quadrants similar to the quadrants selected by the user in the query image or contain quadrants similar to the entire query image. Because it is a generalized distance function, some particular cases of the $\Delta$-distance appear in existing content-based image retrieval systems.ouinonouirechercheInternationa

Storage And Management Of Similar Images

Numerical images are becoming more and more important and an increasing emphasis on multimedia applications has resulted in large volumes of images. However, images need a large memory space to be stored, so their efficient storage and retrieval generate challenges to the database community. This paper proposes a new algorithm for an efficient storage of sets of images. It is based on a version approach used in databases. It shows how to store and operate on similar images; two images are defined as similar if the quad-trees encoding them have only few different nodes. A data structure called Generic Quad-Tree (GQT) is proposed. It optimizes the memory space required to store similar images and allows an efficient navigation among them. An Image Tree stores the ancestors and descendants of an image, like a version hierarchy. Using the Image Tree, the Generic Quad-Tree allows an image to share common parts with its ancestors and descendants. The GQT approach and some algorithms for reading, modifying or removing images from the Generic Quad-Tree are described. Examples using black and white images and gray scale images are presented

TQoS: Transactional and QoS-Aware Selection Algorithm for Automatic Web Service Composition

Web Services are the most famous implementation of service-oriented architectures that has brought some challenging research issues. One of these is the composition, i.e., the capability to recursively construct a composite Web service as a workflow of other existing Web services, which are developed by different organizations and offer diverse functionalities (e.g., ticket purchase, payment), transactional properties (e.g., compensatable or not), and Quality of Service (QoS) values (e.g., execution price, success rate). The selection of a Web service, for each activity of the workflow, meeting the user's requirements, is still an important challenge. Indeed, the selection of one Web service among a set of them that fulfill some functionalities is a critical task, generally depending on a combined evaluation of QoS. However, the conventional QoS-aware composition approaches do not consider the transactional constraints during the composition process. This paper addresses the issue of selecting and composing Web services not only according to their functional requirements but also to their transactional properties and QoS characteristics. We propose a selection algorithm that satisfies user's preferences, expressed as weights over QoS criteria and as risk levels defining semantically the transactional requirements. Proofs and experimental results are presented.ou

Dynamic Composite Web Service Execution by Providing Fault-Tolerance and QoS Monitoring

LNCS n°8954One of the major goals of the Service Oriented Architecture is to support automatic Web Service (WS) composition and execution, allowing a user query to be satisfied by a Composite WS (CWS). User queries express functional and non-functional (QoS) requirements. QoS requirements indicate, for example, the maximum execution time or price allowed for a CWS execution. In this work, we propose a model to support CWS executions while maintaining the QoS requirements, even in presence of failures. QoS monitoring is performed during the entire execution of a CWS in order to satisfy QoS requirements, influencing the choice of the fault-tolerance strategy selection in case of failures.nonouirechercheInternationa

A Framework for Searching Semantic Data and Services with SPARQL

LNCS n°8831The last years witnessed the success of Linked Open Data (LOD) project and the growing amount of semantic data sources available on the web. However, there is still a lot of data that will not be published as a fully materialized knowledge base (dynamic data, data with limited acces patterns, etc). Such data is in general available through web api or web services. In this paper, we introduce a SPARQL-driven approach for searching linked data and relevant services. In our framework, a user data query is analyzed and transformed into service requests. The resulting service requests, formatted for different semantic web services languages, are addressed to services repositories. Our system also features automatic web service composition to help finding more answers for user queries. The intended applications for such a framework vary from mashups development to aggregated search.nonouirechercheInternationa

Synthèse sur les modèles de représentation des relations spatiales dans les images symboliques

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