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Elsevier announced the winners of the 2010 Semantic Web Challenge. The Elsevier sponsored Challenge occurred at the International Semantic Web Conference held in Shanghai, China from 7-11 November, 2010. A jury consisting of seven leading experts from both academia and industry awarded the four best applications with cash prizes exceeding 3000 Euro in total.

Over the last eight years, the Challenge has attracted more than 140 entries. All submissions are evaluated rigorously by a jury composed of leading scientists and experts from industry in a 3 round knockout competition consisting of a poster session, oral presentations and live demonstrations.

Organized this year by Christian Bizer from the Freie Universität Berlin, Germany, and Diana Maynard from the University of Sheffield, UK, the Semantic Web Challenge consists of two categories: “Open Track” and “Billion Triples Track.”

The Open Track requires that the applications can be used by ordinary people or scientists and must make use of the meaning of information on the web. The Billion Triples track requires applications to scale up to deal with huge amounts of information which has been gathered from the open web.

The winners of the 2010 Open Track challenge were the team from Stanford University comprising of Clement Jonquet, Paea LePendu, Sean M. Falconer, Adrien Coulet, Natalya F. Noy, Mark A. Musen, and Nigam H. Shah for “NCBO Resource Index: Ontology-Based Search and Mining of Biomedical Resources”. Their entry provides very clear benefits to the biomedical community, bringing together knowledge from many different entities on the web with a large corpus of scientific literature though the clever application of semantic web technologies and principles.

The second prize in the open track was awarded to the team from Rensselaer Polytechnic Institute comprising of Dominic DiFranzo, Li Ding, John S. Erickson, Xian Li, Tim Lebo, James Michaelis, Alvaro Graves, Gregory Todd Williams, Jin Guang Zheng, Johanna Flores, Zhenning Shangguan, Gino Gervasio, Deborah L. McGuinness and Jim Hendler, for the development of “TWC LOGD: A Portal for Linking Open Government Data” – a massive semantic effort in opening up and linking all the public US government data, and providing the ecosystem and education for re-use.

The third prize in the 2010 Open Track was won by a combined team from the Karlsruhe Institute of Technology, Oxford University and the University of Southern California comprising of Denny Vrandecic, Varun Ratnakar, Markus Krötzsch, and Yolanda Gil for their entry “Shortipedia” – a Web-based knowledge repository and collaborative curating system, pulling together a growing number of sources in order to provide a comprehensive, multilingual and diversived view on entities of interest – a Wikipedia on steroids.

The Billion Triples Track was won by “Creating voiD Descriptions for Web-scale Data” by Christoph Böhm, Johannes Lorey, Dandy Fenz, Eyk Kny, Matthias Pohl, Felix Naumann from Potsdam Univesity, Germany. This entry uses state of the art parallelisation techniques, and some serious cloud computing power, to dissect the enormous Billion Triples dataset into topic-specific views.

Further Information

Further information about the Semantic Web Challenge 2010, the runners-up, all submissions and the evaluation committee is found on the Former Challenges page as well as in the Elsevier Press release about the Semantic Web Challenge 2010.

 

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Blank Node

A blank node is an unnamed node, whose name is set by the underlying RDF software and cannot be guaranteed to have the same name for different sessions. Within a graph, it is guaranteed to resolve to the same thing (not a resource/URI but a separate way to represent a node), and between graphs, “it would be incorrect to assume that blank nodes from different graphs having the same blank node identifiers are the same” (see RDF Primer). If you want multiple independent graphs to refer to the same resource, you have to give it an explicit URI.

The most authoritative source for named graphs (being a W3C Recommendation) is SPARQL. Serialization syntaxes, such as RDF/XML or Turtle, allow you to assign an explicit name (a “blank node identifier”) to a blank node, but this is only to distinguish between different blank nodes or to refer to the same blank node from different triples within the same graph. If you give the same blank node identifier to blank nodes in different graphs, these blank nodes are still different from each other; in fact, there will be no relationship or interaction between them at all.

 

Named Graph

Named Graphs is the idea that having multiple RDF graphs in a single document/repository and naming them with URIs provides useful additional functionality built on top of the RDF Recommendations.

Named Graphs turn the RDF triple model into a quad model by extending a triple to include an additional item of information. This extra piece of information takes the form of a URI which provides some additional context to the triple with which it is associated, providing an extra degree of freedom when it comes to managing RDF data. The ability to group triples around a URI underlies features such as: Tracking provenance of RDF data, Access Control and Versioning.

There’s some useful background available on Named Graph Provenance and Trust,  on Named Graphs in general in a paper about NG4J, and specifically on their use in OpenAnzo.

Named Graphs are an important part of the overall technical framework for managing, publishing and querying RDF and Linked Data, and its important to understand the trade-offs in different approaches to using them.