In this paper, we will discuss the proposed recommendation (March 1999) for an RDF Schema Specification and compare the approach taken in this specification to conventional meta data models. We will point out several pecularities in the RDF schema specification compared to more conventional approaches, which are basically due to the dual role of properties such as subclass and domain both as pr...

RDF and RDF Schema are two W3C standards aimed at enriching the Web with machine-processable semantic data. We have developed Sesame, an architecture for efficient storage and expressive querying of large quantities of metadata in RDF and RDF Schema. Sesame’s design and implementation are independent from any specific storage device. Thus, Sesame can be deployed on top of a variety of storage d...

We study the problem of schema evolution in the RDF data model. RDF and the RDFS schema language are W3C standards for flexibly modeling and sharing data on the web. Although schema evolution has been intensively studied in the database and knowledge-representation communities, only recently has progress been made on the study of RDFS schema evolution. Indeed, the flexible nature of RDF poses n...

In order to realize the vision of the Semantic Web, a semantic model for encoding content in the World Wide Web, efficient storage and retrieval of large RDF data sets is required. A common technique for storing RDF data (graphs) is to use a single relational database table, a triple store, for the graph. However, we believe a single triple store cannot scale for the needs of large-scale applic...

Un défi majeur en informatique est la modélisation et le raisonnement sur les données temporelles. Ce travail est devenu encore plus important avec l'émergence du Web sémantique où de grandes quantités données hétérogènes sont manipulées. Ces données comportent souvent des informations temporelles informelles, semi-formelles ou formelles qui doivent être interprétées par les agents logiciels. D...

Résumé. Le problème de réconciliation de références consiste à décider si deux descriptions provenant de sources distinctes réfèrent ou non à la même entité du monde réel. Dans cet article, nous étudions ce problème quand le schéma des données est décrit en RDFS étendu par certaines primitives de OWL-DL. Nous décrivons et montrons l’intérêt d’une approche logique basée sur des règles de réconci...

Business Intelligence (BI) plays important roles in executive decision making in organizations. Up-to-date information from good data sources always gives advantages to the organization. Nowadays, information in Semantic Webs is considered important source of BI data. It provides machine readable information using the Resource Description Framework (RDF). To perform BI activities on RDF documen...

RDF and RDF Schema provide the first W3C standard to enrich the Web with machine-processable semantic data. However, to be able to use this semantic data, a scalable, persistent RDF store and a powerful query engine using an expressive query language are needed. Sesame is an extensible architecture implementing both of these. Sesame can be based on arbitrary repositories, ranging from tradition...

The AutoMed project uses a hypergraph common data model the HDM to integrate heterogeneous data sources Previous work has shown how data models including the relational ER and XML mod els can be mapped on to HDM to facilitate schema integration RDF is a general purpose language for representing information on the World Wide Web It provides a data model for describing properties of re sources in...