The details of reasoning in RDF [2] and RDFS [1] are generally well known. There is a model-theoretic semantics for RDF [3, 4] and there are sound and complete proof theories for RDF without datatypes [6]. However, the model-theoretic characteristics of RDF have been less studied, particularly when datatypes are added. We show that RDF reasoning can be performed by only considering finite model...

This paper provides a type theoretic foundation for descriptive types that appear in Linked Data. Linked Data is data published on the Web according to principles and standards supported by the W3C. Such Linked Data is inherently messy: this is due to the fact that instead of being assigned a strict a priori schema, the schema is inferred a posteriori. Moreover, such a posteriori schema consist...

The paper presents an introduction to W3C's Simple Knowledge Organisation System (SKOS) , an RDF Schema designed to represent and share controlled vocabularies, such as classifications, glossaries, and thesauri, more simply than ontology languages.

30 Published by the IEEE Computer Society 1089-7801/10/$26.00 © 2010 IEEE IEEE INTERNET COMPUTING I n parallel with the hypertext Web’s continuous development, we’re witnessing an explosion of structured data published on the Web, with companies such as Google, Freebase, Upcoming, eBay, Yahoo, and Amazon competing to gather and publish this content in a way that encourages people to reuse it. T...

Semantic Web applications are striving nowadays for managing changes of persistent resource descriptions created according to RDFS schemata. To cope with this demands, a declarative update language for RDF graphs is proposed, which is based on the paradigms of query and view languages RQL and RVL. This language, called RUL, ensures that the execution of the update primitives on nodes and arcs n...

RDF is the common data model to publish structured data on the Web. RDF data sets are given as subject-predicateobject triples and typically are represented as directed edgelabeled graphs. To make the information represented by such graphs comprehensible, RDF-schema (RDFS) provides concepts to define a class-structure as part of the given RDFgraph and thus supports a more abstract view on the d...

The need to organize and publish metadata about European research results in the field of natural disasters has been met with the help of two innovative technologies: the Open Grid Service Architecture (OGSA) and the Resource Description Framework (RDF). OGSA provides a common platform for sharing distributed metadata securely. RDF facilitates the creation and exchange of metadata. In this pape...

As data is increasingly captured, aggregated, and digitized worldwide, new types of information systems, such as digital libraries and information (subject) gateways, emerge as core technologies of the 21st-century economy. After a rst generation of systems focusing on the accessibility of available information resources, nowadays, high quality information collections are smoothly transformed i...

RDF-based P2P networks have a number of advantages compared to simpler P2P networks such as Napster, Gnutella or to approaches based on distributed indices on binary keys such as CAN and CHORD. RDF-based P2P networks allow complex and extendable descriptions of resources instead of fixed and limited ones, and they provide complex query facilities against these metadata instead of simple keyword...

The RDF data model allows publishing interlinked RDF datasets, where each dataset is independently maintained and is queryable via a SPARQL endpoint. Many applications would benefit from querying the resulting large, decentralized, geo-distributed graph through a federated SPARQL query processor. A crucial factor for good performance in federated query processing is pushing as much computation ...