Tutorial at IASLOD2012

1. Programming with LOD
Fumihiro Kato
Research Organization of Information and Systems
Transdisciplinary Research Integration Center
National Institute of Informatics
1

2. Linked Data Principles
1. Use URIs as names for things
2. Use HTTP URIs so that people can look up
those names.
3. When someone looks up a URI, provide
useful information, using the standards
(RDF, SPARQL)
4. Include links to other URIs, so that they can
discover more things.
2

3. http://dbpedia.org/resource/South_Korea
3

4. 1. request /resource/South_Korea
2. return an HTML document for /resource/South_Korea
Web Browser http://dbpedia.org
4

5. 1. request /resource/South_Korea
2. return an RDF document for /resource/South_Korea
LOD Agent http://dbpedia.org
@prefix dbpedia-owl: <http://dbpedia.org/ontology/> .
@prefix dbpedia: <http://dbpedia.org/resource/> .
dbpedia:Seoul dbpedia-owl:country dbpedia:South_Korea .
dbpedia:JnC dbpedia-owl:hometown dbpedia:South_Korea .
@prefix dbpprop: <http://dbpedia.org/property/> .
dbpedia:JnC dbpprop:origin dbpedia:South_Korea .
dbpedia:Lee_Jae_Jin dbpedia-owl:hometown dbpedia:South_Korea ;
dbpprop:origin dbpedia:South_Korea .
dbpedia:Kang_Sung_Hoon dbpedia-owl:hometown dbpedia:South_Korea ;
dbpprop:origin dbpedia:South_Korea .
dbpedia:Northern_Asia-Pacific_Division_of_Seventh-day_Adventists dbpedia-owl:location dbpedia:South_Korea ;
dbpedia-owl:regionServed dbpedia:South_Korea ;
dbpprop:location dbpedia:South_Korea .
dbpedia:Korean_Amateur_Radio_League dbpedia-owl:regionServed dbpedia:South_Korea ;
dbpprop:regionServed dbpedia:South_Korea .
dbpedia:Asia-Pacific_Association_for_International_Education dbpprop:headquarters dbpedia:South_Korea ;
dbpedia-owl:headquarter dbpedia:South_Korea .
dbpedia:The_Korean_Chemical_Society dbpedia-owl:location dbpedia:South_Korea ;
dbpprop:location dbpedia:South_Korea .
dbpedia:Korean_e-Sports_Association dbpedia-owl:regionServed dbpedia:South_Korea .
dbpedia:Miss_Asia_Pacific_World dbpprop:headquarters dbpedia:South_Korea ;
dbpedia-owl:headquarter dbpedia:South_Korea .
dbpedia:Daegu_Stadium dbpedia-owl:location dbpedia:South_Korea .
dbpedia:Chuncheon_Civic_Stadium dbpedia-owl:location dbpedia:South_Korea .
5

6. RDF Libraries
• Java: Jena, Sesame • Python: rdflib
• C: Redland • Perl: PerlRDF
• C#: dotNetRDF • JavaScript: rdfQuery,
• Ruby: RDF.rb rdfstore-js
• PHP: ARC2, • ....
Graphite
See http://www.w3.org/2001/sw/wiki/Tools
6

7. RDF.rb
• http://rdf.rubyforge.org
• http://github.com/ruby-rdf
• $ gem install linkeddata equivalent-xml
7

8. Reading RDF
1 #!/usr/bin/env ruby
2 # -*- coding: utf-8 -*-
3
4 require 'linkeddata'
5
6 RDF::Reader.open("http://dbpedia.org/resource/South_Korea") do |reader|
7 reader.each do |statement|
8 puts statement.inspect
9 end
10 end
8

9. Reading RDF
1 #!/usr/bin/env ruby
2 # -*- coding: utf-8 -*-
3
4 require 'linkeddata'
5
6 RDF::Reader.open("http://dbpedia.org/resource/South_Korea") do |reader|
7 reader.each do |statement|
8 puts statement.inspect
9 end
10 end
.......
#<RDF::Statement:0x3fd362ca7338(<http://dbpedia.org/resource/South_Korea> <http://dbpedia.org/ontology/PopulatedPlace/areaTotal> 100209.22997701018 .)>
#<RDF::Statement:0x3fd362ca7338(<http://dbpedia.org/resource/South_Korea> <http://dbpedia.org/ontology/PopulatedPlace/areaTotal> 100209.22997701018 .)>
#<RDF::Statement:0x3fd362cabd70(<http://dbpedia.org/resource/South_Korea> <http://dbpedia.org/ontology/PopulatedPlace/areaTotal> 100210.0 .)>
#<RDF::Statement:0x3fd362cabd70(<http://dbpedia.org/resource/South_Korea> <http://dbpedia.org/ontology/PopulatedPlace/areaTotal> 100210.0 .)>
#<RDF::Statement:0x3fd3623772cc(<http://dbpedia.org/resource/South_Korea> <http://dbpedia.org/ontology/PopulatedPlace/populationDensity> 491.0 .)>
#<RDF::Statement:0x3fd3623772cc(<http://dbpedia.org/resource/South_Korea> <http://dbpedia.org/ontology/PopulatedPlace/populationDensity> 491.0 .)>
#<RDF::Statement:0x3fd362c797bc(<http://dbpedia.org/resource/South_Korea> <http://dbpedia.org/ontology/PopulatedPlace/populationDensity> 490.73584350744875 .)>
#<RDF::Statement:0x3fd362c797bc(<http://dbpedia.org/resource/South_Korea> <http://dbpedia.org/ontology/PopulatedPlace/populationDensity> 490.73584350744875 .)>
#<RDF::Statement:0x3fd362c59c28(<http://dbpedia.org/resource/South_Korea> <http://dbpedia.org/ontology/abstract> Corea del Sud, of icialment la República de Corea) és un país de l'Àsia que ocupa la
regió meridional de la península de Corea. Al nord, limita amb Corea del Nord, al qual estava unit fins el 1945. A l'oest, creuant la mar Groga, es troba la República Popular de Xina, i a l'est
, creuant l'Estret de Corea, es troba el Japó. La capital i la ciutat més gran n'és Seül, l'àrea metropolitana de la qual és una de les tres més poblades del món. La llengua oficial de Corea del Sud és el coreà, i és,
actualment, la desena llengua més parlada del món. El nom del país, en coreà, significa "La Gran Nació del Poble Coreà", hom es refereix al país sovint com la "Terra de la Calma del Matí". llegendari Dangun
Kanggeom. L'evidència arqueològica suggereix que els coreans han habitat la península des del Paleolític Baix. Després de la unificació dels Tres Regnes Coreans sota el comandament de Silla el 668 dC, Corea
va romandre com a nació unificada sota les dinasties de Goryeao i Joseaon fins la caiguda de l'Imperi Coreà el 1910. Després de la divisió i de l'establiment de la república moderna de Corea del Sud, el país ha
tingut que reconstruir-se després del període d'explotació japonesa i de la Guerra de Corea. No obstant això, l'estàndard de vida, així com l'economia, van créixer de manera sorprenent des de la dècada de
1980. El 1987, després de diverses manifestacions nacionals, el govern autoritari es va col·lapsar, i des de llavors, s'hi han celebrat eleccions democràtiques cada cinc anys. Avui dia, Corea del Sur és un dels
Estats pioners de la democràcia a Àsia; els ciutadans coreans gaudeixen d'un dels nivells més alts de
......
9

10. Accessing statements
1 #!/usr/bin/env ruby
2 # -*- coding: utf-8 -*-
3
4 require 'linkeddata'
5
6 RDF::Reader.open("http://dbpedia.org/resource/Korea") do |reader|
7 reader.each do |statement|
8 puts "s: #{statement.subject}, p: #{statement.predicate}, o: #{statement.object}"
9 end
10 end
10

11. RDF Serialization
• N-Triples • RDFa
• RDF/XML • JSON-LD
• Turtle (N3) • RDF/JSON
• TriX • ...
11

12. Reading text/n3
1 #!/usr/bin/env ruby
2 # -*- coding: utf-8 -*-
3
4 require 'linkeddata'
5
6 RDF::Reader.open("http://dbpedia.org/data/South_Korea.n3", :format => "n3") do |reader|
7 reader.each do |statement|
8 puts statement.inspect!
9 end
10 end
12

13. Writing RDF
1 #!/usr/bin/env ruby
2 # -*- coding: utf-8 -*-
3
4 require 'linkeddata'
5
6 RDF::Writer.open("writing.ttl") do |writer|
7 subject = RDF::URI("http://dbpedia.org/resource/South_Korea")
8 predicate = RDF::RDFS.label
9 object = RDF::Literal("韓国", :language => :ja)
10 writer << RDF::Steatement.new(subject, predicate, object)
11 end
13

14. Loading and Merging RDF
1 #!/usr/bin/env ruby
2 # -*- coding: utf-8 -*-
3
4 require 'linkeddata'
5
6 graph = RDF::Graph.new
7 graph.load("http://dbpedia.org/resource/South_Korea")
8 puts graph.size
9 graph.load("http://dbpedia.org/resource/Daejeon")
10 puts graph.size
14

15. Querying RDF
1 #!/usr/bin/env ruby
2 # -*- coding: utf-8 -*-
3
4 require 'linkeddata'
5
6 graph = RDF::Graph.new
7 graph.load("http://dbpedia.org/resource/Daejeon")
8 graph.query([RDF::URI("http://dbpedia.org/resource/Daejeon"),
9 RDF::URI("http://dbpedia.org/ontology/country"),
10 nil]).each do |statement|
11 puts statement.object
12 end
dbpedia:South_Korea
dbpedia-owl:country
rdf:type
dbpedia-owl:City
dbpedia:Daejeon
geo:lat
rdfs:label
36.350101
Daejeon
15

16. Defining a vocabulary
1 #!/usr/bin/env ruby
2 # -*- coding: utf-8 -*-
3
4 require 'linkeddata'
5
6 DBP = RDF::Vocabulary.new("http://dbpedia.org/resource/")
7 DBP_ONT = RDF::Vocabulary.new("http://dbpedia.org/ontology/")
8
9 graph = RDF::Graph.new
10 graph.load(DBP.Daejeon)
11 graph.query([DBP.Daejeon, DBP_ONT.country, nil]).each do |statement|
12 puts statement.object
13 end
dbpedia-owl:South_Korea
dbpedia-owl:country
rdf:type
dbpedia-owl:City
dbpedia:Daejeon
geo:lat
rdfs:label
36.350101
Daejeon
16

17. Query SQL SPARQL
DB RDB RDF Store
Model Relational Model RDF Model
17

18. SPARQL
• SPARQL Protocol and RDF Query Language
• W3C Standards
• SQL-like syntax
• Graph Patterns
• Result Formats: XML, JSON, (CSV, TSV)
• $ gem install sparql
18

19. Using SPARQL in RDF.rb
1 #!/usr/bin/env ruby
2 # -*- coding: utf-8 -*-
3
4 require 'linkeddata'
5
6 graph = RDF::Graph.new
7 graph.load("http://dbpedia.org/resource/Daejeon")
8
9 sse = SPARQL.parse("""SELECT ?o
10 WHERE {
11 <http://dbpedia.org/resource/Daejeon> <http://dbpedia.org/ontology/country> ?o .
12 }""")
13
14 sse.execute(graph).each do |solution|
15 puts solution[:o]
16 end
19

20. Querying a SPARQL Endpoint
1 #!/usr/bin/env ruby
2 # -*- coding: utf-8 -*-
3
4 require 'linkeddata'
5
6 client = SPARQL::Client.new("http://dbpedia.org/sparql")
7
8 query = """SELECT ?o
9 WHERE {
10 <http://dbpedia.org/resource/Daejeon> <http://dbpedia.org/ontology/country> ?o .
11 }"""
12
13 client.query(query).each do |solution|
14 puts solution[:o]
15 end
20

21. dbpedia-owl:Country
rdf:type
rdfs:label
dbpedia-owl:City dbpedia-owl:capital dbpedia:South_Korea South Korea
rdf:type
dbpedia-owl:coutnry
dbpedia-owl:Company
dbpedia:Seoul dbpedia-owl:location rdf:type
dbpedia-owl:location
rdfs:label dbpedia:Samsung_Electronics dbpedia-owl:owner
owl:sameAs
dbpprop:foundingYear
dbpedia-owl:Lee_Kun-hee
1969-01-01
Seoul rdfs:label
freebase:Seoul foaf:homepage
삼성전자 rdfs:label
http://global.samsungtomorrow.com/
Samsung Electronics
21

22. PREFIX dbpedia: <http://dbpedia.org/resource/>
PREFIX dbpedia-owl: <http://dbpedia.org/ontology/>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
SELECT ?location ?label
WHERE {
dbpedia:Samsung_Electronics dbpedia-owl:location ?location .
?location rdfs:label ?label .
} dbpedia-owl:Country
rdf:type
rdfs:label
dbpedia-owl:City dbpedia-owl:capital dbpedia:South_Korea South Korea
rdf:type
dbpedia-owl:coutnry
dbpedia-owl:Company
dbpedia:Seoul dbpedia-owl:location rdf:type
dbpedia-owl:location
rdfs:label dbpedia:Samsung_Electronics dbpedia-owl:owner
owl:sameAs
dbpprop:foundingYear
dbpedia-owl:Lee_Kun-hee
1969-01-01
Seoul rdfs:label
freebase:Seoul foaf:homepage
삼성전자 rdfs:label
http://global.samsungtomorrow.com/
Samsung Electronics
22

23. 23

24. 24

25. Querying a SPARQL Endpoint
1 #!/usr/bin/env ruby
2 # -*- coding: utf-8 -*-
3
4 require 'linkeddata'
5
6 client = SPARQL::Client.new("http://dbpedia.org/sparql")
7
8 query = """PREFIX dbpedia: <http://dbpedia.org/resource/>
9 PREFIX dbpedia-owl: <http://dbpedia.org/ontology/>
10 PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
11
12 SELECT ?location ?label
13 WHERE {
14 dbpedia:Samsung_Electronics dbpedia-owl:location ?location .
15 ?location rdfs:label ?label .
16 }"""
17
18 client.query(query).each do |solution|
19 puts solution.inspect
20 end
25

26. PREFIX dbpedia: <http://dbpedia.org/resource/>
PREFIX dbpedia-owl: <http://dbpedia.org/ontology/>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
SELECT ?location ?label
WHERE {
dbpedia:Samsung_Electronics dbpedia-owl:location ?location .
?location a dbpedia-owl:City ;
rdfs:label ?label .
} dbpedia-owl:Country
rdf:type
rdfs:label
dbpedia-owl:City dbpedia-owl:capital dbpedia:South_Korea South Korea
rdf:type
dbpedia-owl:coutnry
dbpedia-owl:Company
dbpedia:Seoul dbpedia-owl:location rdf:type
dbpedia-owl:location
rdfs:label dbpedia:Samsung_Electronics dbpedia-owl:owner
owl:sameAs
dbpprop:foundingYear
dbpedia-owl:Lee_Kun-hee
1969-01-01
Seoul rdfs:label
freebase:Seoul foaf:homepage
삼성전자 rdfs:label
http://global.samsungtomorrow.com/
Samsung Electronics
26

27. 27

28. PREFIX dbpedia: <http://dbpedia.org/resource/>
PREFIX dbpedia-owl: <http://dbpedia.org/ontology/>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
SELECT ?location ?label
WHERE {
dbpedia:Samsung_Electronics dbpedia-owl:location ?location .
?location a dbpedia-owl:City ;
rdfs:label ?label .
FILTER(lang(?label) = ‘ko’) dbpedia-owl:Country
}
rdf:type
rdfs:label
dbpedia-owl:City dbpedia-owl:capital dbpedia:South_Korea South Korea
rdf:type
dbpedia-owl:coutnry
dbpedia-owl:Company
dbpedia:Seoul dbpedia-owl:location rdf:type
dbpedia-owl:location
rdfs:label dbpedia:Samsung_Electronics dbpedia-owl:owner
owl:sameAs
dbpprop:foundingYear
dbpedia-owl:Lee_Kun-hee
1969-01-01
Seoul rdfs:label
freebase:Seoul foaf:homepage
삼성전자 rdfs:label
http://global.samsungtomorrow.com/
Samsung Electronics
28

29. 29

30. SPARQL 1.0
• CRUD
• SELECT
• ASK
• CONSTRUCT
• DESCRIBE
30

31. SELECT
クエリパターン変数の値を取得
SELECT *
WHERE {
?s ?p ?o .
}
LIMIT 100
OFFSET 100
31

32. ASK
PREFIX dbpedia: <http://dbpedia.org/resource/>
PREFIX dbpedia-owl: <http://dbpedia.org/ontology/>
ASK WHERE {
dbpedia:Daejeon ?p ?o .
}
32

33. CONSTRUCT
PREFIX foaf: <http://xmlns.com/foaf/0.1/>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
CONSTRUCT {
?s rdfs:label ?name .
}
WHERE {
?s foaf:name ?name .
}
33

34. DESCRIBE
DESCRIBE <http://dbpedia.org/resource/Tokyo>
34

35. • http://www.w3.org/wiki/SparqlEndpoints
http://www.w3.org/wiki/SparqlEndpoints
http://www.w3.org/wiki/SparqlEndpoints
35

36. • http://www.w3.org/wiki/SparqlEndpoints
http://www.w3.org/wiki/SparqlEndpoints
36 http://labs.mondeca.com/sparqlEndpointsStatus/

37. http://thedatahub.org/group/lodcloud
http://ckan.net/package?res_format=api%2Fsparql
37

38. 38 http://lod.ac/apps/lodac_location/

39. PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX geo: <http://www.w3.org/2003/01/geo/wgs84_pos#>
SELECT DISTINCT ?link ?title ?lat ?long
WHERE {
?link rdfs:label ?title; geo:lat ?lat; geo:long ?long .
FILTER (
?lat > #{sw_lat} && ?lat < #{ne_lat} &&
?long > #{sw_long} && ?long < #{ne_long} &&
lang(?title) = "ja"
)
}
39

40. Query SQL SPARQL
DB RDB RDF Store
Model Relational Model RDF Model
40

41. RDF Store
• Triplestore /
Quadstore / Graph DB
• SPARQL Endpoint
• Options Bigdata®
• RDFS/OWL Inference
• Full text indexing
• Clustering
• See http://en.wikipedia.org/wiki/
Triplestore
41

42. http://virtuoso.openlinksw.com/dataspace/dav/wiki/Main/
42

43. Virtuoso Open Source
• http://virtuoso.openlinksw.com/dataspace/dav/wiki/Main/
• install binary
• install from source
$ tar xvzf virtuoso-opensource-6.1.6.tar.gz
$ cd virtuoso-opensource-6.1.6
$ ./configure
$ make
$ make install
$ /usr/local/virtuoso-opensource/bin/virtuoso-t +configfile /usr/local/virtuoso-
opensource/var/lib/virtuoso/db/virtuoso.ini
43

44. http://localhost:8890/conductor/
44

45. http://localhost:8890/conductor/
45

46. 46

47. 47

48. http://localhost:8890/sparql
48

49. Storage Adapter
• Memory
• Sesame
• Virtuoso
• DataObjects (SQLite3, PostgreSQL)
• RedStore
• 4Store
• MongoDB
• Cassandra
• Talis
• SPARQL
49

50. Virtuoso Adapter
$ gem install rdf-virtuoso
1 #!/usr/bin/env ruby
2 # -*- coding: utf-8 -*-
3
4 require 'linkeddata'
5 require 'rdf/virtuoso'
6
7 REPO_URI = "http://localhost:8890"
8 USER = "dba"
9 PASS = "dba" # this should be changed
10 DBP = RDF::Vocabulary.new("http://dbpedia.org/resource/")
11
12 repo = RDF::Virtuoso::Repository.new(REPO_URI, :username => USER,
13 :password => PASS, :auth_method => 'digest')
14 query = RDF::Virtuoso::Query.select.where([:s, :p, DBP.South_Korea])
15 result = repo.select(query)
16
17 result.each do |solution|
18 puts solution.inspect
19 end
50

51. Summary
• how to consume LOD
• RDF
• SPARQL
51

52. twitter: fumi1
fumi@nii.ac.jp
52