Giovanni Tummarello

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EYAL OREN The Network Institute Vrije Universiteit Amsterdam RENAUD DELBRU, MICHELE CATASTA, RICHARD CYGANIAK Digital Enterprise Research Institute National University of Ireland, Galway HOLGER STENZHORN Institute of Medical Biometry and Medical Informatics, University Medical Center Freiburg, Stefan-Meier-Str. 26, 79104 Freiburg, Germany GIOVANNI(More)
Developers of Semantic Web applications face a challenge with respect to the decentralised publication model: where to find statements about encountered resources. The “linked data” approach, which mandates that resource URIs should be de-referenced and yield metadata about the resource, helps but is only a partial solution. We present Sindice, a lookup(More)
More and more (semi) structured information is becoming available on the Web in the form of documents embedding metadata (e.g., RDF, RDFa, Microformats and others). There are already hundreds of millions of such documents accessible and their number is growing rapidly. This calls for large scale systems providing effective means of searching and retrieving(More)
We demonstrate Sig.ma, both a service and an end user application to access the Web of Data as an integrated information space. Sig.ma uses an holistic approach in which large scale semantic web indexing, logic reasoning, data aggregation heuristics, ad hoc ontology consolidation, external services and responsive user interaction all play together to(More)
Being able to determine the provenience of statements is a fundamental step in any SW trust modeling. We propose a methodology that allows signing of small groups of RDF statements. Groups of statements signed with this methodology can be safely inserted into any existing triple store without the loss of provenance information since only standard RDF(More)
This paper deals with applying semantic Web technologies to the social Web can lead to a social semantic Web, creating a network of interlinked and semantically rich knowledge. One of the most visible trends on the Web is the emergence of social Web sites, which help people create and gather knowledge by simplifying user contributions via blogs, tagging and(More)
The use of RDF data published on the Web for applications is still a cumbersome and resource-intensive task due to the limited software support and the lack of standard programming paradigms to deal with everyday problems such as combination of RDF data from dierent sources, object identifier consolidation, ontology alignment and mediation, or plain(More)
Cloud computing refers to the use of large-scale computer clusters often built from low-cost hardware and network equipment, where resources are allocated dynamically among users of the cluster. While the paradigm is not entirely novel, recent developments in software frameworks for cloud computing are making it increasingly easy for programmers to(More)
On the Web of Data, entities are often interconnected in a way similar to web documents. Previous works have shown how PageRank can be adapted to achieve entity ranking. In this paper, we propose to exploit locality on the Web of Data by taking a layered approach, similar to hierarchical PageRank approaches. We provide justifications for a two-layer model(More)
There has been interest in ranking the resources and generating corresponding expressive descriptions from the Semantic Web recently. This paper proposes an approach for automatically generating snippets from RDF documents and assisting users in better understanding the content of RDF documents return by Semantic Web search engines. A heuristic method for(More)