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)
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)
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)
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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