Stéphane Jean

Querying ontology based database using OntoQL (an ontology query language)

Nowadays, ontologies are used in several research domains by offering the means to describe and represent concepts of information sources Therefore, several approaches and systems storing ontologies and their instances in the same repository (database) have been proposed As a consequence, defining a query language to support ontology-based database (OBDB) becomes a challenge for the database community In this paper, we present OntoQL, an ontology query language for OBDBs Firstly, we present formally the OBDB data model supported by this language Secondly, an overview of the algebra defining the semantics of operators used in OntoQL is described Several query examples showing the interest of this language compared to traditional database query languages are given along this paper Finally, we present a prototype of the implementation of OntoQL.

Cooperative Techniques for SPARQL Query Relaxation in RDF Databases

This paper addresses the problem of failing

An extension of OWL-S with quality standards

mathtt {RDF}

An object-oriented based algebra for ontologies and their instances

queries. Query relaxation is one of the cooperative techniques that allows providing users with alternative answers instead of an empty result. While previous works on query relaxation over

SPL Driven Approach for Variability in Database Design

mathtt {RDF}

Semantic exploitation of persistent metadata in engineering models: Application to geological models

data have focused on defining new relaxation operators, we investigate in this paper techniques to find the parts of an