Search results for "Retrieval"

Special issue on context-aware and mobile multimedia databases and services

2010

International audience

Adding Knowledge Extracted by Association Rules into Similarity Queries

2010

International audience; In this paper, we propose new techniques to improve the quality of similarity queries over image databases performing association rule mining over textual descriptions and automatically extracted features of the image content. Based on the knowledge mined, each query posed is rewritten in order to better meet the user expectations. We propose an extension of SQL aimed at exploring mining processes over complex data, generating association rules that extract semantic information from the textual description superimposed to the extracted features, thereafter using them to rewrite the queries. As a result, the system obtains results closer to the user expectation than i…

Identifying Algebraic Properties to Support Optimization of Unary Similarity Queries

2009

International audience; Abstract. Conventional operators for data retrieval are either based on exact matching or on total order relationship among elements. Neither ofthem is appropriate to manage complex data, such as multimedia data, time series and genetic sequences. In fact, the most meaningful way tocompare complex data is by similarity. However, the Relational Algebra, employed in the Relational Database Management Systems (RDBMS),cannot express similarity criteria. In order to address this issue, we provide here an extension of the Relational Algebra, aimed at representingsimilarity queries in algebraic expressions. This paper identies fundamental properties to allow the integration…

RSS Merger

2010

Editorial Preface

2009

Détection de précurseurs d'évènements basés sur les motifs dans les réseaux sociaux

2021

Les données issues des réseaux sociaux suscitent l'intérêt des chercheurs qui développent des algorithmes et des modèles d'apprentissage automatique pour analyser les interactions et les comportements des utilisateurs. Ces méthodes s'appuient sur la topologie du réseau pour représenter les changements structurels et pour détecter des précurseurs remarquables précédant généralement des évènements majeurs. L'étude présentée dans cet article vise à étudier si certains graphlets (motifs spécifiques) peuvent être considérés comme des précurseurs d'évènements. Nous expérimentons la méthode proposée sur trois ensembles de données de réseaux sociaux. Nous étudions également le rôle joué dans les gr…

Temporal Semantic Centrality for the Analysis of Communication Networks

2012

National audience; De nos jours, la compréhension des communautés en ligne devient un enjeu majeur du Web. Dans cet article nous proposons une nouvelle mesure, la Probabilité de Propagation Sémantique (SPP), qui caractérise la capacité de l'utilisateur à propager un concept sémantique à d'autres utilisateurs, d'une manière rapide et ciblée. La sémantique des messages est analysée selon une ontologie donnée. Nous utilisons cette mesure pour obtenir la Centralité Sémantique Temporelle (TSC) d'un utilisateur dans une communauté. Nous proposons et évaluons une expérimentation de cette mesure, en utilisant une ontologie et des données réelles issues du Web.

Mapping SPARQL Query to temporal logic query based on NμSMV Model Checker to Query Semantic Graphs

2012

International audience; The RDF (W3C standard for metamodeling) language is the most frequently used to represent the semantic graphs. This paper presents a new research combining different fields that are: the semantic web and the model checking. We developed a tool, RDF2NμSMV, which converts RDF graphs into NμSMV language. This conversion aims checking the semantic graphs that have numerous errors of interpretation with the model checker NμSMV in order to verify the consistency of the data. The SPARQL query language is the standard for querying the semantic graph but have a lot of limitations. To this purpose, we define a translation from the SPARQL query language into the temporal logic …

Context-aware semantic Web service discovery protocol

2009

The Web of today represents a broad space where users research, discover and share information. In this context, the process of Web service discovery plays a significant role. Indeed, such process allows linking the information published by service providers and the requests of users, looking for information. Generally, such process involves text or keyword-based techniques. Still, this kind of discovery fails in retrieving only relevant information. Our approach is to design a more " intelligent " system that allows using a knowledge base during the service discovery process, as it is done in the Semantic Web vision. This thesis presents a framework for semantic Web service discovery using…

Towards human exploration of space: the THESEUS review series on cardiovascular, respiratory, and renal research priorities

2016

International audience; The THESEUS project (Towards Human Exploration of Space: aEUropean Strategy) was initiated within the seventh FrameworkProgramme by the European Commission. This project aimed toprovide a cross-cutting, life science-based roadmap for Europe’sstrategy towards human exploration of space, especially for deepspace missions and its relevance to applications on Earth. Toaddress these challenges, relevance of space research on thecardiovascular system, the lungs and kidneys, was discussed in anexpert group and its principal conclusions will be presented in thisarticle.