This document discusses the Semantic Web and linked data. It describes how metadata can be embedded in web documents using microformats like hCard. It explains how RDF can be used to publish and link open data on the web by describing resources and relationships between them. It also discusses ontologies and the OWL language for formally representing concepts and their properties in a web of linked data that can then be queried using SPARQL.

1. Dr. Sabin Buraga
Faculty of Computer Science
“Alexandru Ioan Cuza” University of Iasi, Romania
www.purl.org/net/busaco

2. passion music
painting
@busaco literature
photography
arts
XML Romania
Computer Science professor
Web interaction
research
conferences
semantic design A. I. Cuza
University
teaching books
programming

5. server

6. server
client

7. server
server
client

8. server
server
client
client

9. server
client
server
client
client server

11. Web server

12. Web server Web client(s)

13. Web server Web client(s)
HTTP as protocol

14. URI to address resources

15. HTML as markup language structure

16. CSS for styling presentation

17. anything can link to anything

19. Web as a platform facilitating participation

20. social software
(micro)blogs, social networks, wikis,…

21. tagging
social software
(micro)blogs, social networks, wikis,…

22. from collaboration to trust (?!)

23. RIA – rich interaction between users and applications

24. mash-ups

25. new (e)business models

26. some questions…

27. how about reusing data in other contexts?

28. reality: walled “gardens” (mansions)

29. how about explaining data?

30. in fact, we really want to annotate data by hand?

31. how about enriching data?

32. reality: the need of “intelligent” software

33. how about maturity: from data to knowledge?

34. pragmatism: there are costs, lack of expertise, etc.

35. laziness & resistance to change?
pragmatism: there are costs, lack of expertise, etc.

37. let’s add some semantic spices to old HTML juice

38. first simplest solution: microformats

39. <div class="vcard">
<h3>Personal details</h3>
<img src="sabin-buraga-busaco-csb35.jpg"
alt="Photo of Sabin-Corneliu Buraga" class="photo" />
<p>Full name: <span class="fn">
<span class="given-name">Sabin-Corneliu</span>
<span class="family-name">Buraga</span></span></p>
<p><span class="vevent"><span class="summary">
Date of birth</span>: <abbr class="dtstart"
title="19740107">January 07, 1974</abbr></span></p>
</div>

40. <div class="vcard"> hCard microformat
<h3>Personal details</h3>
<img src="sabin-buraga-busaco-csb35.jpg"
alt="Photo of Sabin-Corneliu Buraga" class="photo" />
<p>Full name: <span class="fn">
<span class="given-name">Sabin-Corneliu</span>
<span class="family-name">Buraga</span></span></p>
<p><span class="vevent"><span class="summary">
Date of birth</span>: <abbr class="dtstart"
title="19740107">January 07, 1974</abbr></span></p>
</div>

41. hCard + hEvent
Operator extension for Firefox in action

42. asserting social relations via XFN microformat

43. result: metadata embedded into Web documents

44. we need a more flexible approach!?

45. creating/using specific vocabularies in a standard way

46. RDF – Resource Description Framework

47. “The Wall is an album made by Pink Floyd.”

48. TheWall isA Album . TheWall madeBy Pink Floyd .

49. TheWall isA Album .
subject predicate object

50. TheWall isA Album .
subject predicate object

51. TheWall isA Album .
subject predicate object

52. TheWall isA Album .
subject predicate object

53. TheWall isA Album .
subject predicate object
URI URI URI

54. TheWall dc:title "The Wall"@en .

55. Dublin Core (DCMI) vocabulary
TheWall dc:title "The Wall"@en .

56. PinkFloyd foaf:made TheWall .

57. FOAF (Friend Of A Friend)
PinkFloyd foaf:made TheWall .

58. PinkFloyd rdf:type mo:MusicGroup .

59. any vocabulary you like… ☺
PinkFloyd rdf:type mo:MusicGroup .

60. using multiple (standardized) vocabularies
web of data

61. Person class
owns
Anca www.flickr.com/laurian
knows
tagged
relation
firstname pig
property
photo
Laurian

62. so, we can publish and reuse public RDF data

64. linked data

65. anyone can say anything about any topic

66. RDF constructs can be used directly into Web pages
RDFa
interesting initiatives: Common Tag, Good Relations

67. other well known vocabularies:
DOAP – Description Of A Project
SIOC – Semantically-Interlinked Online Communities
vocab.org

68. how about specifying concepts, their properties,
relations between concepts, restrictions,…?

69. modeling knowledge via ontologies

70. OWL – Web Ontology Language

71. classes

72. rdf:type
Equinoxe a Album

73. JeanMichelJarre a foaf:Person
RogerWaters a foaf:Person
RogerWaters a db:MusicalArtist
TheWall a db:Album
foaf:Person a owl:Class
db:City a owl:Class
mo:MusicGroup a owl:Class

74. JeanMichelJarre a foaf:Person
RogerWaters a foaf:Person
a class from DBpedia ontology
RogerWaters a db:MusicalArtist
TheWall a db:Album
foaf:Person a owl:Class
db:City a owl:Class
mo:MusicGroup a owl:Class

75. JeanMichelJarre a foaf:Person
RogerWaters a foaf:Person
RogerWaters a db:MusicalArtist
TheWall a db:Album
defining different classes via OWL
foaf:Person a owl:Class
db:City a owl:Class
mo:MusicGroup a owl:Class

76. relations

77. Vangelis foaf:made Direct

78. Vangelis foaf:knows JonAnderson

79. related specifications:
RDF Schema
SKOS – Simple Knowledge Organizational System

80. how about querying such webs of data?

81. SELECT ?title WHERE {
?group a mo:MusicGroup ;
foaf:name "Pink Floyd";
foaf:made ?album .
?album dc:title ?title .
}
ORDER BY ?title LIMIT 3
access to BBC Music
queries about individuals via SPARQL

82. using SPARQL in tools – for example, Zemanta

83. db:MusicalArtist rdfs:subClassOf foaf:Person .
plays a owl:ObjectProperty ;
rdfs:domain db:MusicalArtist ;
rdfs:range mo:Song .
RogerWaters plays If .

84. db:MusicalArtist rdfs:subClassOf foaf:Person .
plays a owl:ObjectProperty ;
rdfs:domain db:MusicalArtist ;
rdfs:range mo:Song .
RogerWaters plays If .
must be a song!

85. db:MusicalArtist rdfs:subClassOf foaf:Person .
plays a owl:ObjectProperty ;
rdfs:domain db:MusicalArtist ;
rdfs:range mo:Song .
RogerWaters plays If .
must be an artist

86. db:MusicalArtist rdfs:subClassOf foaf:Person .
plays a owl:ObjectProperty ;
rdfs:domain db:MusicalArtist ;
rdfs:range mo:Song .
RogerWaters plays If .
must be an artist
and a person, too

87. db:MusicalArtist rdfs:subClassOf foaf:Person .
plays a owl:ObjectProperty ;
rdfs:domain db:MusicalArtist ;
rdfs:range mo:Song .
RogerWaters plays If .
query regarding knowledge (e.g., classes) inference

88. www.mkbergman.com/new-version-sweet-tools-sem-web/
more things to come…

89. thank you!

90. Dr. Sabin Buraga
www.purl.org/net/busaco
twitter.com/busaco