Ian Millard

SPARQL query rewriting for implementing data integration over linked data

There has been lately an increased activity of publishing structured data in RDF due to the activity of the Linked Data community. The presence on the Web of such a huge information cloud, ranging from academic to geographic to gene related information, poses a great challenge when it comes to reconcile heterogeneous schemas adopted by data publishers. For several years, the Semantic Web community has been developing algorithms for aligning data models (ontologies). Nevertheless, exploiting such ontology alignments for achieving data integration is still an under supported research topic. The semantics of ontology alignments, often defined over a logical frameworks, implies a reasoning step over huge amounts of data, that is often hard to implement and rarely scales on Web dimensions. This paper presents an algorithm for achieving RDF data mediation based on SPARQL query rewriting. The approach is based on the encoding of rewriting rules for RDF patterns that constitute part of the structure of a SPARQL query.

RKBExplorer.com: a knowledge driven infrastructure for linked data providers

RKB Explorer is a Semantic Web application that is able to present unified views of a significant number of heterogeneous data sources. We have developed an underlying information infrastructure which is mediated by ontologies and consists of many independent triple-stores, each publicly available through both SPARQL endpoints and resolvable URIs. To realise this synergy of disparate information sources, we have deployed tools to identify co-referent URIs, and devised an architecture to allow the information to be represented and used. This paper provides a brief overview of the system including the underlying infrastructure, and a number of associated tools for both knowledge acquisition and publishing.

Tracing the provenance of linked data using voiD

In the open world of the (Semantic) web, a world where increasingly diverse materials from disparate sources of different qualities are being made available, an automatic mechanism for the provision of provenance information of these sources is needed. This paper describes voidp, a provenance extension for the void vocabulary, that allows data publishers to specify the provenance relationships of their data. We enumerate voidps classes and properties, and describe a use case scenario. A wider uptake of voidp by dataset publishers will allow data consuming tools to take advantage of these metadata providing consumers with the origin, i.e., the provenance, of what is being consumed.

Contextually aware information delivery in pervasive computing environments

This paper outlines work in progress related to the construction of a system which is able to deliver information in a contextually sensitive manner within a pervasive computing environment, through the use of semantic and knowledge technologies. Our approach involves modelling of task and domain as well as location and device. We discuss ideas and steps already taken in the development of prototype components, and outline our future work in this area.

Domain-Specific Backlinking Services in the Web of Data

This paper describes an Open Linked Data backlinking service, a generic architecture component to support the discovery of useful links between items across highly connected data sets. Using Public Sector Information (PSI) currently available as Linked Data, we demonstrate that contemporary publishing practices do not adequately support the ability to navigate or automatically traverse between resources published by different vendors, or the capacity to discover information relevant to a particular URI. Although some useful services in this area have been developed, such as large triple indexes of published data, and the collection of same. As relationships between individuals, we believe that an important component is missing: a mechanism to discover the backlinks to relevant resources that cannot be found by direct URI resolution. We present the implementation of such a component, integrating data from various PSI sources.