This document discusses the National Széchényi Library's process of publishing its data as linked open data. It began by developing SRU and SKOS interfaces, then realized it had the components needed for linked data - SKOS thesauri, URL-based record access via LibriUrl, and SRU search of records. It focused on developing cool URIs, identifiers, content negotiation, the RDFDC vocabulary, and an RDF database. XSLT was used to convert MARCXML to RDFDC, and a FOAF file was generated from authority records. The OPAC was modified to support HTML link auto-discovery to the RDF. The library's data is now available as linked open data via S

1. Linked Data at the NationalLinked Data at the National
Széchényi Library : road to theSzéchényi Library : road to the
publicationpublication
SWIB10 : SEMANTIC WEB IN BIBLIOTHEKENSWIB10 : SEMANTIC WEB IN BIBLIOTHEKEN
Cologne, 29–30 November, 2010Cologne, 29–30 November, 2010
ÁdámÁdám HorváthHorváth
National Széchényi LibraryNational Széchényi Library

2. 2 Linked Data at the National Széchényi
ContentsContents
Why I am hereWhy I am here
Background information on NSZLBackground information on NSZL
Road to the publicationRoad to the publication
Current developments and future plansCurrent developments and future plans

3. 3 Linked Data at the National Széchényi
The newsThe news
The National Széchényi Library (NSZL) hasThe National Széchényi Library (NSZL) has
recently published its entire OPAC andrecently published its entire OPAC and
Digital Library and the correspondingDigital Library and the corresponding
authority data as Linked Open Data.authority data as Linked Open Data.
(2010.04.20)(2010.04.20)

4. 4 Linked Data at the National Széchényi
The newsThe news
The used vocabularies areThe used vocabularies are
– RDFDC for bibliographic data,RDFDC for bibliographic data,
– FOAF for nameFOAF for namess, and, and
– SKOS for subject terms and geographicalSKOS for subject terms and geographical
namesnames

5. 5 Linked Data at the National Széchényi
The newsThe news
 NSZL uses CoolURIsNSZL uses CoolURIs
 Every resource has both RDF and HTMLEvery resource has both RDF and HTML
representationrepresentation
 Our RDFDC, FAOF and SKOS statements areOur RDFDC, FAOF and SKOS statements are
linked togetherlinked together
 Our name authority is matched with the DBPediaOur name authority is matched with the DBPedia
name filesname files
 URI aliases are handled as owl:sameAsURI aliases are handled as owl:sameAs
statementsstatements
 NSZL also supports the HTML link auto-discoveryNSZL also supports the HTML link auto-discovery

6. 6 Linked Data at the National Széchényi
Information infrastructure of NSZLInformation infrastructure of NSZL
Integrated library systemIntegrated library system
– AmicusAmicus
• Consortium systemConsortium system
• ViewsViews
• Oracle basedOracle based
• Authority handlingAuthority handling
• Do not handle all thesaurus relation typesDo not handle all thesaurus relation types
• Products moduleProducts module
• Z39.50 serverZ39.50 server

7. 7 Linked Data at the National Széchényi
Information infrastructure of NSZLInformation infrastructure of NSZL
OPACOPAC
– LibriVisionLibriVision
• HTMLHTML
• XML and XSLT basedXML and XSLT based
• Z39.50 clientZ39.50 client
• Session basedSession based

8. 8 Linked Data at the National Széchényi
Information infrastructure of NSZLInformation infrastructure of NSZL
Thesaurus handlingThesaurus handling
– RelexRelex
• Contains general terms and geographical namesContains general terms and geographical names
• It uses all possible relation type available in ISO2788It uses all possible relation type available in ISO2788
• It also contains UDC equivalents and coordinatesIt also contains UDC equivalents and coordinates
• Relex can produce MARC outputRelex can produce MARC output
• Relex uses the descriptors themselves as identifiersRelex uses the descriptors themselves as identifiers
• Subject terms in Amicus is based on RelexSubject terms in Amicus is based on Relex

9. 9 Linked Data at the National Széchényi
Information infrastructure of NSZLInformation infrastructure of NSZL
MARC is HUNMARCMARC is HUNMARC
– MARC21 basedMARC21 based
– No punctuation marc in recordsNo punctuation marc in records
– More subfieldsMore subfields
– Punctuation is program generatedPunctuation is program generated
– MARC21 tools and utilities can’t be usedMARC21 tools and utilities can’t be used

10. 10 Linked Data at the National
Information infrastructure of NSZLInformation infrastructure of NSZL
The IT department containsThe IT department contains
– ProgrammersProgrammers
– System librariansSystem librarians
– Maintenance stuffMaintenance stuff

11. 11 Linked Data at the National
Information infrastructure of NSZLInformation infrastructure of NSZL
The IT department is responsible forThe IT department is responsible for
– Integrated library systemIntegrated library system
– Developing digital libraryDeveloping digital library
– Developing other utilitiesDeveloping other utilities
– Maintaining the whole IT infrastructureMaintaining the whole IT infrastructure
Not responsible forNot responsible for
– DigitisationDigitisation
– HomepageHomepage

12. 12 Linked Data at the National
Road to the publicationRoad to the publication

13. 13 Linked Data at the National
Motivation of our semantic webMotivation of our semantic web
developmentsdevelopments
Personal interestPersonal interest
Interested colleaguesInterested colleagues
– Kornél Horváth (horvath.kornel@oszk.hu)Kornél Horváth (horvath.kornel@oszk.hu)
– Zsolt Zachár (zachar.zsolt@oszk.hu)Zsolt Zachár (zachar.zsolt@oszk.hu)
Semantic web is a cool thingSemantic web is a cool thing
My friends are also publishing their dataMy friends are also publishing their data
Our role is to provide dataOur role is to provide data

14. 14 Linked Data at the National
Carrying out the developmentCarrying out the development
There were no specific projectThere were no specific project
Small developments pointing to the sameSmall developments pointing to the same
directiondirection
We developed it when time permittedWe developed it when time permitted

15. 15 Linked Data at the National
The very first stepsThe very first steps
ONE2 projectONE2 project
– Interoperability projectInteroperability project
– Z39.50Z39.50
– SRU emerged by the end of the projectSRU emerged by the end of the project
– Semantic web was also mentionedSemantic web was also mentioned

16. 16 Linked Data at the National
SRU interface for AmicusSRU interface for Amicus
TEL-ME-MOR projectTEL-ME-MOR project
– To make NSZL searchable on the TEL portal viaTo make NSZL searchable on the TEL portal via
SRUSRU
YAZ Proxy was usedYAZ Proxy was used
– SRU/Z39.50 gatewaySRU/Z39.50 gateway
– User defined XSLTUser defined XSLT
– Result set is according to the TEL ApplicationResult set is according to the TEL Application
profileprofile

17. 17 Linked Data at the National
SRU interface for AmicusSRU interface for Amicus
The important resultsThe important results
– URL based searchURL based search
– XML result setXML result set
• TTELAPELAP
• MARCXMLMARCXML
– RDFDC is provided via YAZ ProxyRDFDC is provided via YAZ Proxy

18. 18 Linked Data at the National
Development of LibriUrlDevelopment of LibriUrl
The requirement was toThe requirement was to
– make LibriVision OpenUrl compatiblemake LibriVision OpenUrl compatible
– provide access to OPAC records via URLprovide access to OPAC records via URL
The problem was that LibriVision isThe problem was that LibriVision is
– Session based and requires loginSession based and requires login
LibriUrlLibriUrl
– URL based search interface for the OPACURL based search interface for the OPAC
– DDeveloped by NSZL on the bases of a vendoreveloped by NSZL on the bases of a vendor
software codesoftware code

19. 19 Linked Data at the National
Development of LibriUrlDevelopment of LibriUrl
LibriUrl search:LibriUrl search:
http://link.oszk.hu/libriurl.php?http://link.oszk.hu/libriurl.php?
LN=en&DB=any&SRY=an&SRE=2616972LN=en&DB=any&SRY=an&SRE=2616972
LibriUrl side effectsLibriUrl side effects
– Search for Amicus number is a link to a specificSearch for Amicus number is a link to a specific
recordrecord
– Our records became bookmarkable and linkableOur records became bookmarkable and linkable
and OpenSearchableand OpenSearchable

20. 20 Linked Data at the National
How does it work?How does it work?

21. 21 Linked Data at the National
How does it work?How does it work?

22. 22 Linked Data at the National

23. 23 Linked Data at the National

24. 24 Linked Data at the National
DemonstrationDemonstration

25. 25 Linked Data at the National
DemonstrationDemonstration

26. 26 Linked Data at the National
Development of LibriUrlDevelopment of LibriUrl
The importance of LibriUrlThe importance of LibriUrl
– It was behind of our CoolURIIt was behind of our CoolURI
http://link.oszk.hu/libriurl.php?http://link.oszk.hu/libriurl.php?
LN=en&DB=any&SRY=an&SRE=2616972LN=en&DB=any&SRY=an&SRE=2616972

27. 27 Linked Data at the National
SKOSifying the thesaurusSKOSifying the thesaurus
TelPlus projectTelPlus project
– Thesaurus in SKOS for search refinementThesaurus in SKOS for search refinement
SKOS conversionSKOS conversion
– SKOS is converted from the MARC output ofSKOS is converted from the MARC output of
RelexRelex
– Not every thesaurus relation type is convertedNot every thesaurus relation type is converted
– UDC and coordinates are also not includedUDC and coordinates are also not included

28. 28 Linked Data at the National
SKOSifying the thesaurusSKOSifying the thesaurus
Concept identifier is an IRI compatibleConcept identifier is an IRI compatible
descriptor:descriptor:
– 150 ** a150 ** a abszurd drámaabszurd dráma
– <skos:Concept<skos:Concept
rdf:about="http://nektar.oszk.hu/auth/rdf:about="http://nektar.oszk.hu/auth/
abszurd_drámaabszurd_dráma">">

29. 29 Linked Data at the National
SKOSifying the thesaurusSKOSifying the thesaurus
Serving SKOS to TelPlusServing SKOS to TelPlus
– The SKOS XML file is indexed by Zebra andThe SKOS XML file is indexed by Zebra and
served via SRUserved via SRU
– http://193.6.201.195:9996/skos?http://193.6.201.195:9996/skos?
version=1.1&operation=searchRetrieve&query=version=1.1&operation=searchRetrieve&query=
%22Gravenhage%22Gravenhage
%22&startRecord=1&maximumRecords=10%22&startRecord=1&maximumRecords=10
– It is not RDF/XMLIt is not RDF/XML

31. 31 Linked Data at the National
SKOSifying the thesaurusSKOSifying the thesaurus
Importance of SKOS developmentImportance of SKOS development
– Having a conversion tool for creating SKOSHaving a conversion tool for creating SKOS
recordsrecords

32. 32 Linked Data at the National
LIBRIS as an exampleLIBRIS as an example
ELAG, 2008, WageningenELAG, 2008, Wageningen
– LIBRIS’ linked open data was presentedLIBRIS’ linked open data was presented
– Content negotiationContent negotiation
– Cool URICool URI
– Link relLink rel

33. 33 Linked Data at the National
Focusing to the publicationFocusing to the publication
Realised that we have almost everything toRealised that we have almost everything to
be able to publish our data as LODbe able to publish our data as LOD
We hadWe had
– SKOSSKOS
– LibriUrl (accessing OPAC records via URL)LibriUrl (accessing OPAC records via URL)
– YAZ Proxy - SRU (URL based search inYAZ Proxy - SRU (URL based search in
Amicus)Amicus)
– LIBRIS as an exampleLIBRIS as an example

34. 34 Linked Data at the National
Focusing to the publicationFocusing to the publication
What were missingWhat were missing
– Name convention of resourcesName convention of resources
– IdentifiersIdentifiers
– Content negotiationsContent negotiations
– RDFDCRDFDC
– RDF databaseRDF database
– FOAFFOAF
– Link rel metatags in the OPAC headerLink rel metatags in the OPAC header
– Creating linksCreating links

35. 35 Linked Data at the National
Name conventionName convention
Resource name for documentsResource name for documents
– /resource/manifestation/2645471/resource/manifestation/2645471
Name for RDF representationName for RDF representation
– /data/manifestation/2645471/data/manifestation/2645471
Name for HTML representationName for HTML representation
– /hu/manifestation/2645471/hu/manifestation/2645471
– /en/manifestation/2645471/en/manifestation/2645471

36. 36 Linked Data at the National
Name conventionName convention
Resource name for authorityResource name for authority
– /resource/auth/33589/resource/auth/33589
Name for RDF representationName for RDF representation
– /data/auth/33589/data/auth/33589
Name for HTML representationName for HTML representation
– /auth/33589/auth/33589

37. 37 Linked Data at the National
IdentifiersIdentifiers
DocumentsDocuments
• Amicus number (MARC 001)Amicus number (MARC 001)
Subject authority (thesaurus)Subject authority (thesaurus)
• The descriptor itself with some conversion rulesThe descriptor itself with some conversion rules
NamesNames
• Special number stored in the Amicus databaseSpecial number stored in the Amicus database

38. 38 Linked Data at the National
Content negotiationContent negotiation
Implementation of content negotiationImplementation of content negotiation
– 303 redirection was chosen303 redirection was chosen

39. 39 Linked Data at the National

40. 40 Linked Data at the National

41. 41 Linked Data at the National
Creating RDF for catalogue recordsCreating RDF for catalogue records
Creating „RDFDC”Creating „RDFDC”
XSLT does the jobXSLT does the job
– It is MARCXML RDF/XML conversionIt is MARCXML RDF/XML conversion
• Modification of the MARC to TEL ApplicationModification of the MARC to TEL Application
profile conversionprofile conversion
– Creates links to subjects and namesCreates links to subjects and names
Used vocabulariesUsed vocabularies
– Dublin CoreDublin Core
– BIBOBIBO

42. 42 Linked Data at the National
Installation of RDF databaseInstallation of RDF database
JenaJena
Joseki SPARQL endpointJoseki SPARQL endpoint

43. 43 Linked Data at the National
Creating FOAF for namesCreating FOAF for names
Batch processBatch process
– The name index of Amicus is usedThe name index of Amicus is used
FOAF is stored in and served from JenaFOAF is stored in and served from Jena
During update always the entire FOAFDuring update always the entire FOAF
dataset is rebuiltdataset is rebuilt

44. 44 Linked Data at the National
Contents of JenaContents of Jena
Names (FOAF)Names (FOAF)
Subject authority (SKOS)Subject authority (SKOS)
– It is still available from Zebra via SRUIt is still available from Zebra via SRU
Catalogue records (RDFDC)Catalogue records (RDFDC)
All of our linked data can be searchedAll of our linked data can be searched
via SPARQLvia SPARQL

45. 45 Linked Data at the National
Creating HTML link auto-discoveryCreating HTML link auto-discovery
In the head of our OPAC extendedIn the head of our OPAC extended
view pagesview pages
<link rel="meta"<link rel="meta"
type="application/rdf+xml"type="application/rdf+xml"
title="RDF Version"title="RDF Version"
href="http://nektar.oszk.hu/data/manifestathref="http://nektar.oszk.hu/data/manifestat
ion/2645471" />ion/2645471" />

46. 46 Linked Data at the National
Creating linksCreating links
Links to NSZL resourcesLinks to NSZL resources
– Link from RDFDC to nameLink from RDFDC to namess andand
subjectsubjectss
<dcterms:creator<dcterms:creator
rdf:resource="http://nektar.oszk.hu/resource/rdf:resource="http://nektar.oszk.hu/resource/
auth/33589"/>auth/33589"/>
<dc:creator>Jókai Mór (1825-1904)</dc:creator><dc:creator>Jókai Mór (1825-1904)</dc:creator>

47. 47 Linked Data at the National
Creating linksCreating links
 Links to external resourcesLinks to external resources
– Link from the name authority records to DBpediaLink from the name authority records to DBpedia
<foaf:Person<foaf:Person
rdf:about="http://nektar.oszk.hu/resource/auth/33589">rdf:about="http://nektar.oszk.hu/resource/auth/33589">
<foaf:name>Jókai Mór (1825-1904)</foaf:name><foaf:name>Jókai Mór (1825-1904)</foaf:name>
<<owl:sameAsowl:sameAs rdf:resource="http://rdf:resource="http://dbpedia.orgdbpedia.org/resource/M/resource/M
%C3%B3r_J%C3%B3kai"/>%C3%B3r_J%C3%B3kai"/>

48. 48 Linked Data at the National
Resolving the URL of documentsResolving the URL of documents
The URL of the documentThe URL of the document
– /resource/manifestation/2645471/resource/manifestation/2645471
RDF is requestedRDF is requested
– Redirection to /data/manifestation/2645471Redirection to /data/manifestation/2645471
– PHP program gathersPHP program gathers
• MARCXMLMARCXML
• Name idsName ids
– XSLT creates RDF/XML with linksXSLT creates RDF/XML with links

49. 49 Linked Data at the National
Resolving the URL of documentsResolving the URL of documents
Link generation to SKOSLink generation to SKOS
– Automatic conversionAutomatic conversion
• from the literalfrom the literal
– <dcterms:subject>abszurd dráma<dcterms:subject>abszurd dráma
</dcterms:subject></dcterms:subject>
• to the Conceptto the Concept
– <dcterms:subject<dcterms:subject
rdf:resource="http://nektar.oszk.hu/resource/auth/abszurdrdf:resource="http://nektar.oszk.hu/resource/auth/abszurd
_dráma"/>_dráma"/>

50. 50 Linked Data at the National
Resolving the URL of documentsResolving the URL of documents
Link generation to FOAFLink generation to FOAF
– The XSLT gets the name ids as parameters andThe XSLT gets the name ids as parameters and
creates the linkscreates the links
<dc:creator>Jókai Mór (1825-1904)</dc:creator><dc:creator>Jókai Mór (1825-1904)</dc:creator>
<dcterms:creator<dcterms:creator
rdf:resource="http://nektar.oszk.hu/resource/authrdf:resource="http://nektar.oszk.hu/resource/auth
/33589"/>/33589"/>

53. 53 Linked Data at the National
Resolving the URL of documentsResolving the URL of documents
Sample URL of a documentSample URL of a document
/resource/manifestation/2645471/resource/manifestation/2645471
HTML is requestedHTML is requested
– Redirection toRedirection to
/hu/manifestation/2645471 or/hu/manifestation/2645471 or
/en/manifestation/2645471/en/manifestation/2645471
– Nektar proxy calledNektar proxy called

54. 54 Linked Data at the National
Resolving the URL of documentsResolving the URL of documents
Nektar proxyNektar proxy
– Java servlet (substitution of LibriUrl)Java servlet (substitution of LibriUrl)
– It doesIt does
• Loging into LibriVision and getting session idLoging into LibriVision and getting session id
• Searching for the manifestation id and gettingSearching for the manifestation id and getting
query id, etcquery id, etc
• Sending present request and getting the searchSending present request and getting the search
result pageresult page
• Creating the final HTML pageCreating the final HTML page
– Replacing URL-s, filling in the header, etcReplacing URL-s, filling in the header, etc

57. 57 Linked Data at the National
Resolving the URL of authority dataResolving the URL of authority data
Sample URL of an authority recordSample URL of an authority record
/resource/auth/33589/resource/auth/33589
RDF is requestedRDF is requested
– Jena is searched via the Joseki SPARQLJena is searched via the Joseki SPARQL
endpointendpoint
– RDF/XML is given backRDF/XML is given back

60. 60 Linked Data at the National
Resolving the URL of authority dataResolving the URL of authority data
Sample URL of an authority recordSample URL of an authority record
/resource/auth/33589/resource/auth/33589
HTML is requestedHTML is requested
– Jena is searched via the Joseki SPARQLJena is searched via the Joseki SPARQL
endpointendpoint
– RDF/XML is given backRDF/XML is given back
– XSLT creates the HTML pageXSLT creates the HTML page

63. 63 Linked Data at the National
Current activitiesCurrent activities
Improving RDFDCImproving RDFDC
– Making RDFDC 100% compliant with theMaking RDFDC 100% compliant with the
DCMI Metadata TermsDCMI Metadata Terms
• Proper usage of dc:creator and dcterms:creatorProper usage of dc:creator and dcterms:creator
• Better conversion of title and publisherBetter conversion of title and publisher

64. 64 Linked Data at the National
Current activitiesCurrent activities
Improving SKOSImproving SKOS
– Inserting UDC equivalent of ConceptsInserting UDC equivalent of Concepts
– Inserting USE AND and other relationshipsInserting USE AND and other relationships
– Inserting coordinates of geographicalInserting coordinates of geographical
namesnames

65. 65 Linked Data at the National
Current activitiesCurrent activities
Improving FOAFImproving FOAF
– Including organisationsIncluding organisations

66. 66 Linked Data at the National
Current activitiesCurrent activities
VIAFVIAF
– Creating links from our FOAF to VIAFCreating links from our FOAF to VIAF
Studying VirtuosoStudying Virtuoso
– Jena might be changed to VirtuosoJena might be changed to Virtuoso
FRBRising the OPACFRBRising the OPAC

67. 67 Linked Data at the National
FRBRising the OPACFRBRising the OPAC
MethodMethod
– Collecting works, expressions andCollecting works, expressions and
manifestations from the „MARC dump” ofmanifestations from the „MARC dump” of
our catalogueour catalogue
– Creating RDF representations based on IanCreating RDF representations based on Ian
Davis: Expression of Core FRBR ConceptsDavis: Expression of Core FRBR Concepts
in RDFin RDF
– Loading the RDF representations into JenaLoading the RDF representations into Jena
– Showing the work tree based onShowing the work tree based on
manifestation idmanifestation id

68. 68 Linked Data at the National
FRBRising the OPACFRBRising the OPAC
Scope (at first)Scope (at first)
– Printed monographsPrinted monographs
• Excluding multivolumeExcluding multivolume
– This is a „post” FRBRisationThis is a „post” FRBRisation
UsageUsage
– OPAC/Extended view/Link to the work treeOPAC/Extended view/Link to the work tree
First resultsFirst results

71. 71 Linked Data at the National
Current activitiesCurrent activities
Digital Library: OSZKDKDigital Library: OSZKDK
– Mainly contains deposit copiesMainly contains deposit copies
– It is also published as LODIt is also published as LOD
OAI-ORE is being implemented as aOAI-ORE is being implemented as a
container of structural metadatacontainer of structural metadata
– Used parts: resource map, aggregationUsed parts: resource map, aggregation
– Used vocabularies: DC, BIBOUsed vocabularies: DC, BIBO
– It is in test phase nowIt is in test phase now

73. 73 Linked Data at the National
Planned discovery of OAI-OREPlanned discovery of OAI-ORE
„„Link rel” in the head of the OPAC ofLink rel” in the head of the OPAC of
OSZKDKOSZKDK
– <link rel="meta"<link rel="meta"
type="application/rdf+xml"type="application/rdf+xml"
title=„OAI-ORE resource map"title=„OAI-ORE resource map"
href="http://oszkdk.oszk.hu/rem/drj/869" />href="http://oszkdk.oszk.hu/rem/drj/869" />

74. 74 Linked Data at the National
One resource map of test OSZKDKOne resource map of test OSZKDK
<rdf:Description<rdf:Description
rdf:about="rdf:about="http://oszkdk.oszk.hu/rem/drj/876http://oszkdk.oszk.hu/rem/drj/876">">
<<rdf:typerdf:type
rdf:resource="http://www.openarchives.org/ore/termsrdf:resource="http://www.openarchives.org/ore/terms
//ResourceMapResourceMap"/>"/>
<<dcterms:modifieddcterms:modified
rdf:datatype="http://www.w3.org/2001/XMLSchema#drdf:datatype="http://www.w3.org/2001/XMLSchema#d
ate">2010-04-07</dcterms:modified>ate">2010-04-07</dcterms:modified>
<<dcterms:creatordcterms:creator
rdf:resource="http://oszkdk.oszk.hu/"/>rdf:resource="http://oszkdk.oszk.hu/"/>
<<ore:describesore:describes
rdf:resource="rdf:resource="http://oszkdk.oszk.hu/aggr/drj/876http://oszkdk.oszk.hu/aggr/drj/876"/>"/>
</rdf:Description></rdf:Description>

75. adam@oszk.huadam@oszk.hu
Thank you for your attentionThank you for your attention