The Semantic Web is an extension of the current Web in which information is given well defined meaning, better enabling computers and people to work in cooperation. The technical foundation of the Semantic Web is RDF, a semi-structured data model resembling directed labelled graphs. Semantics of data are given by ontologies that are encoded using a specialized vocabulary called RDF Schema. Firs...

As RDF reaches maturity, there is an increasing need for tools that support it. A common and natural representation for RDF data is a directed labeled graph. Although there are tools to edit and/or browse RDF graph representations, we found their architecture rigid and not easily amenable to producing effective visual representations, especially for large RDF graphs. We present here GViz, a gen...

With the development of the Semantic Web, an increasingly large number of organizations represent their data in RDF format. A single machine cannot efficiently process complex queries on RDF graphs. It becomes necessary to use a distributed cluster to store and process large-scale RDF datasets that are required to be partitioned. In this paper, we propose a semantic-aware partitioning method fo...

The Resource Description Framework (RDF) is a Semantic Web standard that provides a data language, simply called RDF, as well as a lightweight ontology language, called RDF Schema. We investigate embeddings of RDF in logic and show how standard logic programming and description logic technology can be used for reasoning with RDF. We subsequently consider extensions of RDF with datatype support,...

The EBI RDF platform[1] was released in 2013 and provides access to several EBI databases as RDF Linked Data. The RDF platform provides a SPARQL endpoints and a Linked Data browser to the data in addition to making data dumps available over FTP. At release the RDF platform contained data from the Reactome, BioModels, BioSamples, Gene Expression Atlas and ChEMBL databases in addition to the coll...

With the success of the semantic web infrastructures for storing and querying RDF data are gaining importance. A couple of systems are available now that provide basic database functionality for RDF data. Compared to modern database systems, RDF storage technology still lacks sophisticated optimization methods for query processing. Current work in this direction is mainly focussed on index stru...

ASHACL, a variant of the W3C Shapes Constraint Language, is designed to determine whether an RDF graph meets some conditions. These conditions are grouped into shapes, which validate whether particular RDF terms each meet the constraints of the shape. Shapes are themselves expressed as RDF triples in an RDF graph, called a shapes graph.

One of the main aims of the so-called Web of Data is to be able to handle heterogeneous resources where data can be expressed in either XML or RDF. The design of programming languages able to handle both XML and RDF data is a key target in this context. In this paper we present a framework called XQOWL that makes possible to handle XML and RDF/OWL data with XQuery. XQOWL can be considered as an...

As Resource Description Framework (RDF) reaches maturity, there is an increasing need for tools that support it. A common and natural representation for RDF data is a directed labeled graph. Although there are tools to edit and/or browse RDF graph representations, we found their architecture rigid and not easily amenable to producing effective visual representations, especially for large RDF gr...