In this work, we build a large scale reasoning engine under temporal RDFS semantics using MapReduce. We identify the major challenges of applying MapReduce framework to reason over temporal information, and present our solutions to tackle them.

The foundation language for the Semantic Web is the Resource Description Framework (RDF). RDF is intended to describe the Web metadata so that the Web content is not only machine readable but also machine understandable. In this way one can better support the interoperability of Web applications. RDF Schema (RDFS) is used to describe different RDF vocabularies (schemas), i.e., the classes and p...

The Linked Open Data (LOD) cloud brings together information described in RDF and stored on the web in (possibly distributed) RDF Knowledge Bases (KBs). The data in these KBs are not necessarily described by a known schema and many times it is extremely time consuming to query all the interlinked KBs in order to acquire the necessary information. To tackle this problem, we propose a method of s...

Both Topic Maps and RDF are popular semantic web standards designed for machine processing of web documents. Since these representations were originally created for different purposes, they have conceptual differences in their data models, and therefore have different tools to parse, store, and query them. However, there are more tools to handle RDF data than those existing for Topic Maps. Our ...

This paper presents inference rules for Resource Description Framework (RDF), RDF Schema (RDFS) and Web Ontology Language (OWL). Our formalization is based on Notation 3 Logic, which extended RDF by logical symbols and created Semantic Web logic for deductive RDF graph stores. We also propose OWL-P that is a lightweight formalism of OWL and supports soft inferences by omitting complex language ...

We describe the results of the RDF(S) activity within the Open Grid Forum (http://www.ogf.org) (OGF) Database Access and Integration Services (DAIS) Working Group (http://forge.gridforum.org/projects/ dais-wg) whose objective is to develop standard service-based grid access mechanisms for data expressed in RDF and RDF Schema. We produce two specifications, focused on the provision of SPARQL que...

This paper presents the working draft MOFTM (Meta-Object Facility) metamodels for the Resource Description Framework (RDF Schema) and the Web Ontology Language (OWL), two of the six metamodels currently envisioned for the Ontology Definition Metamodel (ODM) standards effort in the Object Management Group (OMG®), which enable model-driven development of RDF vocabularies and OWL ontologies, respe...

The Linked Data cloud grows rapidly as more and more knowledge bases become available as Linked Data. Knowledge-based applications have to rely on efficient implementations of query languages like SPARQL, in order to access the information which is contained in large datasets such as DBpedia, Freebase or one of the many domain-specific RDF repositories. However, the retrieval of specific facts ...