http://www.w3c.org.il/node/256

1. ‫הווב הסמנטי‬
‫אייל סלע‬
‫מנהל פרויקטים, איגוד האינטרנט‬
‫הישראלי ומשרד ה-‪ W3C‬הישראלי‬
‫אוניברסיטת בר אילן – 1102/6/61‬

2. ‫תוכן עניינים‬
‫• מבוא - איגוד האינטרנט הישראלי ו-‪W3C‬‬
‫• אודות ה-‪Semantic Web‬‬
‫• דוגמאות‬
‫2‬

3. ‫איגוד האינטרנט הישראלי‬
‫• שלוחת האיגוד הבינלאומי‬
‫• עמותה ללא מטרת רווח‬
‫• פועל לקידום האינטרנט והטמעתו בישראל‬
‫כתשתית טכנולוגית, מחקרית, חינוכית, חברתית‬
‫ועסקית‬
‫‪www.w3c.org.il‬‬

4. ‫‪W3C‬‬
‫• ארגון בינלאומי‬
‫• כ-053 ארגונים‬
‫• פורום ניטראלי ליצירת תקני הווב‬
‫• משימה:‬
‫להוביל את הרשת למיצוי הפוטנציאל על ידי פיתוח‬
‫פרוטוקולים וקווים מנחים שיאפשרו את צמיחתה לטווח‬
‫ארוך.‬
‫‪www.w3c.org.il‬‬
‫4‬

5. ‫תוכן עניינים‬
‫מבוא - איגוד האינטרנט הישראלי ו-‪W3C‬‬ ‫•‬
‫טכנולוגיות ווב חדשות‬ ‫•‬
‫הווב הסמנטי‬ ‫•‬
‫הווב הנייד‬ ‫•‬
‫5‬

6. W3C-‫ווב סמנטי ב‬
www.w3.org/standards/semanticweb
6

7. Semantic Web
Web of Data
7

8. ‫דף אינטרנט רגיל בנוי באופן שבני אדם יכולים‬
‫להבין את תוכנו‬
‫4‪j.mp/w3cyd‬‬
‫8‬

9. 9

10. ‫אבל המחשב יודע רק להציג את המידע.‬
‫הוא אינו מבין איזה תוכן קיים בו.‬
‫01‬

11. j.mp/w3cyd4
11

12. ‫מטרת הווב הסמנטי היא לגשר את הפער‬
‫21‬

13. Semantic web is about…
machine interpretability of Web
content
applications can
process the content of information
instead of just
presenting it to humans
j.mp/w3cowl
13

14. ‫תאור מידע, ברמת הקוד (כלומר, הוספת‬
‫משמעות, סמנטיקה), כך שמכונות יכולות‬
‫להבין את תוכנו.‬

15. Machines can read information about me
15

16. My blog on the Rich Snippets testing tool
j.mp/b7cIO9
16

17. ‫או את זכויות היוצרים באתר שלי‬
‫71‬

18. 18

19. 19

20. ‫זהו בעצם מנגנון מוסכם (סטנדרט) לייצוג נתונים.‬

21. ‫הרשת הופכת מאוסף של מסמכים (שרק בני אדם‬
‫מבינים)‬
‫למאגר נתונים (שמכונות יכולות "להבין").‬
‫12‬

22. ‫אפליקציות‬
‫אבסטרקציה‬
‫נתונים‬
‫נתונים ב-‪RDF‬‬ ‫‪XML‬‬ ‫דפי אינטרנט‬ ‫מאגרי נתונים‬
‫‪j.mp/w3civan‬‬

23. The semantic technology stack
23

24. Semantic
technology
stack
Web of Web of data
documents
24

25. XML
syntax for structured documents
&
URIUniform resource Identifier
25

26. RDF
26

27. The building block of the Semantic Web
Resource Description Framework (RDF)
27

28. The building block of the Semantic Web
Resource Description Framework (RDF)
‫שיטה לתאר דברים‬
28

29. (also) things not on the web
29

30. 1. With RDF we describe resources in terms of
properties and property values
<http://www.productivewise.com/> <CreatedBy> "Eyal Sela" .
subject predicate object
30

31. 2. Which are represented as a graph of nodes and arcs
http://www.productivewise.com
CreatedBy
Eyal sela
31

32. 3. things are identified by URI
http://www.productivewise.com/#me
32

33. 1. With RDF we describe resources in terms of
properties and property values
2. Which are represented as a graph of nodes
and arcs
3. Things are identified by URIs
33

34. ‫למשל....‬
‫43‬

35. RDF ‫איך מבטאים את המידע בעזרת‬
there is a Person identified by http://www.w3.org/People/EM/contact#me, whose name is
Eric Miller, whose email address is em@w3.org, and whose title is Dr.
j.mp/w3crdf
35

36. ‫נראה (למשל) ככה‬
XML-based syntax
36

37. ‫פריטים מוויקיפדיה על מפה‬
DBpedia Mobile
renders a map
containing
information about
nearby locations
from the DBpedia
dataset.
beckr.org/DBpediaMobile
37

38. ‫רגע.‬
‫כשאומרים ‪ GivenName‬מתכוונים לשם של אדם או אולי‬
‫משתנה בתוכנה?‬
‫83‬

39. ‫לא יודע...‬
‫93‬

40. ‫לכן משתמשים ב ‪URIs‬‬
‫04‬

41. http://xmlns.com/foaf/0.1/givenname The given name of
some person.
j.mp/9tGcBh
41

42. These are known as Vocabularies
set of URIs defined for some specific purpose
(E.g. identify employees)
42

43. Why use URIs as properites?
1.Distinguish properties
2. Properties treated as resources (add
information about them)
43

44. Another person/program familiar with the
vocabulary will know what is meant by this
relationship.
44

45. ...‫אז בעצם‬
‫רק אפליקציות שיודעות לקרוא‬
RDF ‫ מסוים יבינו הצהרות‬vocabulary
.‫שמשתמשות בו‬
RDF statements using URIs from vocabularies
convey the specific meanings associated with
terms only to applications written to
process these vocabularies.
45

46. An application cannot actually "understand" such
statements.
any more than a database system "understands" terms like "employee" or "salary" in
processing a query like
SELECT NAME FROM EMPLOYEE WHERE SALARY > 35000.
46

47. Vocabularies you should know
47

48. FOAF - describing people, the links between them
and the things they create and do
Group
Image
LabelProperty
OnlineAccount
Organization
Project
Account
Age
Birthday
Depiction
familyName
Knows
…
48

49. Decentralization: The Future of Online Social
Networking
you (will) have a
personal Website, with
your photos, your family
tree, your business
details, and aggregators
then (will) turn this into
added value by finding
the links across the
whole web. ]Economist 2008[ )illustration by David Simonds(
j.mp/w3cweb
49

50. Good relations - product, price, and company
ActualProductOrServiceInstance
BusinessEntity
BusinessEntityType
BusinessFunction
DayOfWeek
DeliveryChargeSpecification
-DeliveryMethod
DeliveryModeParcelService
LocationOfSalesOrServiceProvisioning
N-Ary-Relations
Offering
…
j.mp/w3cbar6
50

51. Dublin Core - 15 properties to describe esources
(books, video, sound, image, web pages)
Title
Creator
Subject
Description
Publisher
Contributor
Date
Type
Format
Identifier
Source
Language
Relation
Coverage
Rights
51

52. ‫האם יש הבדל בין זה‬
‫לזה?‬
‫25‬

53. 53

54. But RDF can’t describe vocabularies
– types of things (like exterms:Person)
– properties (like exterms:age and exterms:creation-date)
– types of things that can serve as the subjects or objects of
statements involving those properties (like specifying that the value of
an exterms:age property should always be an xsd:integer).
 54

55. RDFS
55

56. RDFS
defines classes (groups of related resources) and
properties (relationships between resources) that are
used to describe classes, properties and other resources.
j.mp/w3crdfs
56

57. RDFS does NOT specify a vocabulary of descriptive
properties such as "author". it specifies mechanisms to
do that.
57

58. 58

59. 59

60. Inferred properties
(<http://…/isbn/000651409X> rdf:type #Fiction)

61. RDFS Limits
Can’t say:
– “the domain of hasParent is Child when applied
to Human and Calf when applied to Elephants”
–“all instances of person have a mother that is also
a person”, or that persons have exactly 2 parents
–isAncestorOf is a transitive property
–isMarriedTo or isPeeredWith is symmetrical
–identification of objects with different URI-s
j.mp/cO5kdK :`(
61

62. OWL
62

63. 63

64. Term equivalences
 For classes:
 owl:equivalentClass: two classes have the same
individuals
 owl:disjointWith: no individuals in common
 For properties:
 owl:equivalentProperty
 remember the a:author vs. f:auteur
 owl:propertyDisjointWith
 For individuals:
 owl:sameAs: two URIs refer to the same concept
(“individual”)
 owl:differentFrom: negation of owl:sameAs

65. Classes in OWL
 In RDFS, you can subclass existing classes… that’s
all
 In OWL, you can construct classes from existing
ones:
 enumerate its content
 through intersection, union, complement

66. SPARQL endpoint
• SPARQL endpoint is a URI to which Queries can be
sent, and which returns answers to the Queries as
a response.
j.mp/semqle

67. !‫וגם אתם יכולים להשתמש במידע הזה‬
querying RDFa from rotten tomatos :
SELECT ?z ?i ?o
FROM NAMED <http://www.w3.org/2007/08/pyRdfa/extract?uri=http://www.rottentomatoes.com/m/karate_kid_2010/>
FROM NAMED <http://www.w3.org/2007/08/pyRdfa/extract?uri=http://www.rottentomatoes.com/m/a_team/>
FROM NAMED <http://www.w3.org/2007/08/pyRdfa/extract?uri=http://www.rottentomatoes.com/m/prince_of_persia_sands_of_time/>
FROM NAMED <http://www.w3.org/2007/08/pyRdfa/extract?uri=http://www.rottentomatoes.com/m/sex_and_the_city_2/>
FROM NAMED <http://www.w3.org/2007/08/pyRdfa/extract?uri=http://www.rottentomatoes.com/m/1208173-splice/>
WHERE { GRAPH ?dummy {
?x <http://rdf.data-vocabulary.org/#name> ?z .
?x <http://rdf.data-vocabulary.org/#summary> ?i .
?w <http://opengraphprotocol.org/schema/image> ?o .
}
}
http://dbpedia.org/sparql
67

68. RDF ‫ - הדגמה לשאילתות‬SPARQLer
sw.cs.technion.ac.il/eyalsela/

69. SPRQL - example
Select the names and addresses of schools in London:
prefix sch-ont: <http://education.data.gov.uk/def/school/>
SELECT ?name ?address1 ?address2 ?postcode ?town WHERE {
?school a sch-ont:School;
sch-ont:establishmentName ?name;
sch-ont:districtAdministrative
<http://statistics.data.gov.uk/id/local-authority-district/00AA> .
}
ORDER BY ?name
~result
j.mp/w3cbar5
69

70. Let us put it together
:‫לסיכום‬
 What we need for a Web of Data:
 use URI-s to publish data, not only full
documents
 allow the data to link to other data
 characterize/classify the data and the links (the
“terms”( to convey some extra meaning
 and use standards for all these!|

71. ‫יישומים‬

72. ?Linked Data ‫מי מפרסם‬
New York Times
Newsweek
dbPedia
Data.gov.uk
Tesco
Best Buy
BBC
LOD
‫דרופל‬
www.isoc.org.il
www.w3c.org.il 72
eyal@isoc.org.il

73. Facebook
RDFa ‫יש‬
RDFa ‫אין‬
73

74. ‫בוגר אוניברסיטאות שכתבו עליהם בניו-יורק‬
‫טיימס‬
Who Went Where
1. colleges and
universities
from DBpedia.
2. queries DBpedia for
the NYT identifiers of
all the alumni
3. identifiers are then
used to query the
New York Times
Article Search API
j.mp/w3cbar4
74

75. j.mp/tseyqw
75

76. ‫מתכונים בגוגל‬
‫‪j.mp/w3cqug‬‬
‫67‬

77. ‫• בעיקר מיקרופורמט‬
‫• מיעוט/אי שימוש במילונים קיימים‬
‫• החלטה על ידי מנועי החיפוש בלבד?‬
‫‪schema.org‬‬

78. Schema.org ‘s Type Hierarchy
• CreativeWork
• Event
• Intangible
• Organization
• Person
• Place
• Product

79. Data.gov Earthquakes + Exhibit =
j.mp/w3cqwg
79

80. dbrec
http://dbrec.net
80

81. j.mp/w3cben1
81

82. police.uk
82

83. RelFinder
j.mp/w3cda2
83

84. Faceted browsing
wiki.dbpedia.org/FacetedSearch
84

85. ‫תקנים – מה חדש?‬
‫58‬

86. HTML5 (!)
– HTML+RDFa
– HTML Microdata
86

87. RDFa API draft by RDFa working group
document.getElementsByType(“http://xmlns.com/foaf/0.1/Person")
The specification details how
a developer may extract, store
and query structured data
contained within one or more
RDFa-enabled documents.
j.mp/w3car2
87

88. RDB2RDF
Use Cases and Requirements for Mapping Relational
Databases to RDF
example
Wordpress….
88

89. ...‫עדכונים אחרונים‬
• 2011-05-25 HTML Microdata
• 2011-05-12 SPARQL 1.1 Update
• 2011-05-12 RIF In RDF
• 2011-05-10 RDF Interfaces 1.0
• 2011-05-10 Pointer Methods in RDF 1.0
• 2011-05-10 HTTP Vocabulary in RDF 1.0
• 2011-05-10 Representing Content in RDF 1.0
• 2011-04-19 RDFa API
• 2011-03-24 A Direct Mapping of Relational Data to RDF
• 2011-03-24 R2RML: RDB to RDF Mapping Language
• 2011-03-31 RDFa Core 1.1
• ……

90.  ‫תודה‬
‫אייל סלע‬
eyal@isoc.org.il
@isociltech @eyalsela
w3c.org.il/news/256 :‫המצגת‬