Semantic web

From NektarWiki

National Széchényi Library (national library of Hungary) on the semantic web

News

04/2011 Switch to Virtuoso, SPARQL endpoint URL change

It is available on the following URLs:
http://setaria.oszk.hu/sparql and http://setaria.oszk.hu/isparql The previous URL is automatically redirected to the recent one, so if you have a bookmark by the outdated URL, you can find the new SPARQL endpoint on the new address without any modification of your old bookmark. The technical change from the previous version is the usage of Virtuoso instead of Joseki.

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17/09/2010 - End of SDB switching and size of the RDF database

RDB database switching to SDB project has finished. You can use the new database.
Our triplestore contains 19 300 000 statements.

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02/09/2010 - SDB switching

We are switching from Jena RDB database to SDB. In the transition period you can use the former database.
Upon completion of the upload we will inform you and you can start using the new database for searches.

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06/2010 - Size of the RDF database

Our triplestore contains 17 500 000 statements.

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05/2010 - Data access through SPARQL endpoint

All bibliographic data is now available via the SPARQL endpoint.

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04/2010 - Data access in Linked Open Data (LOD) format

The National Széchényi Library (NSZL) has recently published its entire OPAC and Digital Library and the corresponding authority data as Linked Open Data.

The used vocabularies are

• RDFDC for bibliographic data,
• FOAF for name authority entries, and
• SKOS for subject terms and geographical names.

NSZL uses CoolURIs. Every resource has both RDF and HTML representation.
Our RDFDC, FAOF and SKOS statements are linked together. Our name authority is matched with the DBPedia name files and URI aliases are handled as owl:sameAs statements.

NSZL also supports the HTML link auto-discovery.

Examples are:

OPAC records (RDFDC):
http://nektar.oszk.hu/resource/manifestation/2645471

Digital Library record (RDFDC):
http://oszkdk.oszk.hu/resource/DRJ/404

Name authority (FOAF):
http://nektar.oszk.hu/resource/auth/33589

Subject term (SKOS):
http://nektar.oszk.hu/resource/auth/magyar_irodalom

NSZL followed and adapted the Swedish LIBRIS´s practices. We are grateful for Martin Malmsten for his help. Skosification was done under the TELplus project with the precious feedbacks of Antoine Isaac.

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Background

Implementation

National Széchényi Library followed the Christian Bizer, Richard Cyganiak, Tom Heath: How to publish Linked Data on the Web (tutorial). The implementation principles are described in a presentation. LinkedDataAtNszl (PDF)

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SPARQL endpoint

It is available on the following URLs:
http://setaria.oszk.hu/sparql and http://setaria.oszk.hu/isparql The previous URL is automatically redirected to the recent one, so if you have a bookmark by the outdated URL, you can find the new SPARQL endpoint on the new address without any modification of your old bookmark. The technical change from the previous version is the usage of Virtuoso instead of Joseki.

Sample query:

PREFIX skos: <http://www.w3.org/2004/02/skos/core#>
SELECT ?s ?p ?o
WHERE {
  ?s ?p ?o .
  ?s skos:prefLabel "kutya"@hu .
  }