The database, semantic web, and linked data communities have proposed solutions that federate queries over multiple data sources using a single data model. Nowadays, the data retrieval requirements originating from versatile ...

The Semantic Web languages RDFS and OWL have been around for some time now. However, the presence of these languages has not brought the breakthrough of the Semantic Web the creators of the languages had hoped for. OWL has ...

Log files of online shared workspaces contain rich information that can be further analyzed. In this paper, log-file information is used to extract object-centric and user-centric social networks. The object-centric social ...

In SPARQL, conjunctive queries are expressed by using shared variables across sets of triple patterns, also called basic graph patterns. Based on this characterization, basic graph patterns in a SPARQL query can be ...

Information technology has the potential to increase the pace of scientific progress by helping researchers in formulating, publishing and finding information. There are numerous projects that employ ontologies and Semantic ...

This overview paper briefly describes problems we need to tackle if we want to meaningfully and efficiently process emergent knowledge. By this term we essentially mean knowledge continually emerging in a bottom-up manner ...

In this paper we define a formal model for a Public Ad- ministration service on the basis of the Web Service Modeling Ontology (WSMO). For this purpose we employ the generic public service object model of the Governance ...

Medical practice today still entails sorting through scattered information on a specific patient. Making things more difficult, the EU, in bringing its member states closer together, is encouraging people¿s mobility, and ...

Data on the Semantic Web is semi-structured and does not follow one fixed schema. Faceted browsing is a natural technique for navigating such data, partitioning the information space into orthogonal conceptual dimensions. ...

Knowledge domains and their semantic representations via ontologies are typically subject to change in practical applications. Additionally, engineering of ontologies often takes place in distributed settings where multiple ...