Youness Bazhar

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Recently, ontology-based databases (OBDB) have been developed as a solution to store and manipulate, efficiently and in a scal-able way, ontologies together with data they describe. Currently, existing OBDB propose weak solutions to calculate derived (non-canonical) concepts. Indeed, these solutions are internal to the OBDB and specific to the ontology(More)
—With the increasing size of models and their instances , the management of models in databases becomes a necessity. Persistent Model Management Systems (PMMS) aim at providing a persistent environment for the management of instances, models and metamodels. They consist of (1) a database that stores metamodels, models and their instances, and (2) an(More)
The increasing number of information systems modeling formalisms raises several problems such as data integration or data exchange. To address these problems, several meta-modeling systems have been proposed. However, few of them use a database as a back-end repository in order to offer a persistent solution for addressing over sized models. Yet, with the(More)
Several ontologies are currently defined for various domains and for a wide range of applications. As a consequence, two problems shall be addressed (1) the size of data described by ontologies is huge and (2) existing ontologies are not all similar: they can be defined with different formalisms leading to different types of ontologies (canonical, non(More)
Model persistence has always been one of the major interests of the model-driven development community. In this context, Persistent Meta-Modeling Systems (PMMS) have been proposed as database environments dedicated to meta-modeling and model management. Yet, if existing PMMS store meta-models, models and instances, they provide mechanisms that are sometimes(More)
Cesdernì eres années ont vu l'´ emergence des ontologies com-me modèles de représentation de connaissances. Elles ontété utilisées dans de nombreux domaines et pour des applications très variées. Cette large utilisation a engendré deux probì emes. D'une part, les données existantes qui sont dé-crites par des ontologies sont volumineuses, et d'autre part,(More)
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