This document provides an introduction to the Semantic Web, covering topics such as what the Semantic Web is, how semantic data is represented and stored, querying semantic data using SPARQL, and who is implementing Semantic Web technologies. The presentation includes definitions of key concepts, examples to illustrate technical aspects, and discussions of how the Semantic Web compares to other technologies. Major companies implementing aspects of the Semantic Web are highlighted.

1. Tomasz Pluskiewicz PGS Software
INTRODUCTION TO
THE SEMANTIC WEB
2012-11-28
Introduction to the Semantic Web 1

2. Agenda
 What is the Semantic Web?
 What is data in the Semantic Web?
 Storing and publishing semantic data
 Querying the Semantic Web
 What is there for developers?
 How does the Semantic Web compare?
 So who actually does the Semantic Web?
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3. What is the Semantic Web?
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Introduction to the Semantic Web

4. What is the Semantic Web?
 Semantics = meaning (from Greek)
 Set of practices and standards
 Synonymous or related to:
 Web of data
 Linked data (cloud)
 Giant Global Graph (GGG)
 Web 3.0
 Open Data
 Big Data
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5. So what is it about?
 Allowing machines to understand data
 Ease sharing and mixing data
 Extend the World Wide Web rather than
replace it
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6. Little bit of history
 1969: paper Semantic Information Processing
by Ross Quillial
 1980s: CYC and WordNet
 mid- to late 1990s: Tim Berners-Lee coins the
term Semantic Web
 Today: dbpedia: 1.2m triples
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7. Semantic Web building blocks
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8. Representation
The basics of semantic data
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Introduction to the Semantic Web

9. It’s all about resources
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10. It’s all about resources
 Extensive use of URIs (and most often URLs)
 (Almost) everyting is a URI
 Example URIs:
 http://infusion.com/people/tpluskiewicz
 urn:isbn:1898432023
 http://xmlns.com/foaf/0.1/firstName
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11. It’s all findable about resources
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 Identifier
 Representation
 Resource itself
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 URI (URL?)
 HTML, RDF
 Described object
Introduction to the Semantic Web
Identifier URI should be different than the representationURI
Identifiers should not change

12. Cool URIs
 Resource and representation have different
URIs
 Hash URIs
 http://www.example.com/about#alice
 http://www.example.com/about.html
 „Normal” URIs
 http://www.example.com/id/bob
 http://www.example.com/people/bob.html
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13. Representing the data
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14. Resource Description Format
 Facts and relations organized in triples
 Triples mimic natural language sentences
 Graphical representation is a directed graph
My name is Tomasz Pluskiewicz.
My age is 26.
I work for PGS Software.
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15. Resource Description Framework
ex:tpluskiewicz
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Tomasz
Pluskiewicz
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foaf:fullName
ex:PGS-
Software

16. Serializing RDF triples
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 RDF/XML (.rdf)
 Notation3 (.n3)
 N-Triples (.nt)
 Turtle (.ttl)
 JSON-LD
 TriG (.trig)
 TriX (.trix)
 application/rdf+xml
 text/n3
 text/plain
 text/turtle
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Format MIME type
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17. RDF/XML vs Turtle
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 Difficult to author
 Verbose
 No cannonical
serialization
 Simple
 Concise
 Has means of
further compressing
content
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RDF/XML Turtle
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18. There can be multiple graphs
 Sets of triples form graphs
 Graphs can be named with a URI
 Named graph are also resources, hence there
can be triples describing those graphs
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19. Adding meaning
The basics of semantic data
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Introduction to the Semantic Web

20. Representing the data
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21. Basics of RDF(S) resources
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 rdfs:Resource
 rdfs:Class
 rdfs:Property
 rdfs:Datatype
 rdfs:Literal
 rdf:type
 rdfs:label
 rdfs:subClassOf
 rdfs:subPropertyOf
 rdfs:range
 rdfs:domain
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classes properties
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22. Web Ontology Language
 OWL: Lite, DL and Full
 OWL 2: EL, QL and RL
 Defining constraints
 Enables defining complex rules
 Uses specialized syntaxes
 Base terms: owl:Thing, owl:Nothing,
owl:DatatypeProperty, owl:ObjectProperty,
owl:sameAs
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23. Common ontologies
 Friend of a Friend
 Dublin Core
 SIOC
 SKOS
 UMBEL
 Suggested Upper Merged Ontology
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 Geonames
 BIBO

24. Specialized ontologies
 Gene Ontology
 GOLD (General O. for Linguistic Description)
 Foundational Model of Anatomy
 GoodRelations
 Lexvo
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25. Storing and publishing
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Introduction to the Semantic Web

26. Storing in relational databases
 Mapping tables to triples:
 D2RQ
 R2RML
 Ultrawrap
 Using RDBMS with RDF built-in capabilities
 Oracle 11g
 Virtuoso
 Jena SDB
 IBM DB2
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27. Native triplestores
 Using native triple (quad) stores
 Virtuoso
 AllegroGraph
 BigOWLIM
 Jena TDB
 4store
 Stardog
 Dydra
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28. Publishing data easily
 Embedding semantic markup in HTML
 Microformats
 Microdata
 RDFa
 Directly publishing RDF documents
http://manu.sporny.org/2011/uber-comparison-rdfa-md-uf/
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29. Microformats example
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<ul>
<li>
Joe Doe</li>
<li>
The Example Company
</li>
<li>
604-555-1234</li>
<li>
<a>
Website</a>
</li>
</ul>
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<ul class="vcard">
<li class="vcard">
Joe Doe</li>
<li class="org">
The Example Company
</li>
<li class="tel">
604-555-1234</li>
<li>
<a class="url">
Website</a>
</li>
</ul>
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30. Microdata example
<section itemscope itemtype="http://data-vocabulary.org/Person">
Hello, my name is <span itemprop="name">John Doe</span>,
I am a <span itemprop="title">graduate research assistant</span>
at the <span itemprop="affiliation">University of Dreams</span>.
My friends call me <span itemprop="nickname">Johnny</span>.
You can visit my homepage at
<a href="http://www.JohnnyD.com"
itemprop="url">www.JohnnyD.com</a>.
<section itemprop="address" itemscope
itemtype="http://data-vocabulary.org/Address">
I live at <span itemprop="street-address">1234 Peach Drive</span>
<span itemprop="locality">Warner Robins</span> ,
<span itemprop="region">Georgia</span>.
</section>
</section>
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31. RDFa example
<p xmlns:dc="http://purl.org/dc/elements/1.1/"
about="http://www.example.com/books/wikinomics">
In his latest book
<cite property="dc:title">Wikinomics</cite>,
<span property="dc:creator">Don Tapscott</span>
explains deep changes in technology, demographics and business.
The book is due to be published in
<span property="dc:date" content="2006-10-01">October
2006</span>.
</p>
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32. Querying the Semantic Web
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33. Publishing queryable data
 SPARQL Protocol and RDF Query Language
 Remote queries through SPARQL Endpoints
 SPARQL 1.1 features:
 ASK, SELECT, DESCRIBE, CONSTRUCT
 Aggregates
 Federated queries
 Extensibilty, XPath, subqueries
 SPARQL Update
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34. SPARQL Examples
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35. SPARQL + rules = SPIN
 SPARQL Inferencing
 Developed by TopQuadrant
 Components of SPIN:
 Represent SPARQL queries as RDF triples
 Allow modularizing queries with spin:Function and
spin:Template
 spin:MagicProperty
 ASK to create constraints
 CONSTRUCT to create rules
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36. Constraints and rules
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37. Functions and templates
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38. What is there for developers?
 dotNetRDF
 Jena/ARQ
 Rdflib
 RDF.rb
 EasyRdf
 Rdfquery
 Redland
 (Web)Protégé
 TopBraid Composer
 NeOn
 OntoWiki
 Semantic MediaWiki
 Cubic Web
Programming tools Design tools and frameworks

39. Semantic Web vs X
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Introduction to the Semantic Web

40. Semantic Web vs XML
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 Data representation
(model)
 Graph
 xsd and XPath
 Schema defined with
RDFS or OWL
 URI identifiers
 Data serialization
(syntax)
 Tree
 xsd and XPath
 DTD or XML schema
 No built-in identifiers
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Semantic Web (RDF) XML
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41. Semantic Web vs REST
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 URIs identify resources
 HTTP encouraged to
allow dereferencing
 Uniform RDF messages
 Resources are linked
(triples)
 Application specific
 Resource Identification
 Uniform Interface
 Self-Describing
Messages
 Hypermedia Driving
Application State
 Stateless Interactions
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Semantic Web REST
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42. Semantic Web vs RDBMS
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 SPARQL
 Felxible and extensible
schema
 Easy data distribution
 Depends on vendor
 Easier process BI
 Open World
 SQL
 Schema must be defined
first and is rather rigid
 Painful replication
 ACID Transactions
 Strict ETL
 Closed World
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Semantic Web Relational databases
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43. Semantic Web vs NoSQL
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 SPARQL
 Graph
 Schemaless
 Named graphs
 Built on standards and
interoperability
 Can seem scientific and
complicated
 Various APIs
 Graph, doc, key-value
 Schemaless
 Documents (doc DBs)
 Tackle specific problems
(latency, scale, perf.)
 Designed for easy
adoption
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Semantic Web NoSQL
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44. Who actually does the Semantic Web?
Is it happening?
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Introduction to the Semantic Web

45. Linked data and open data
 Dbpedia
 Freebase
 Geonames
 Social data
 Media
 Government data
 Publications
 Many many other
 datahub.io
 lod.openlinksw.com
 data.gov
 data.gov.uk
 datadotgc.ca
 openlibrary.org
 bnb.data.bl.uk
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http://richard.cyganiak.de/2007/10/lod/lod-datasets_2011-09-19_colored.html

46. Who does the Semantic Web?
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 IBM DB2
 Open Services
Lifecycle
Collaboration
 Linked Data
Platform
 Oracle 11g
 Triplestore
 Reasoner
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IBM Oracle
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47. Who does the Semantic Web?
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 Webmaster tools
 Knowledge graph
 Freebase
 RDFa/Microdata
(also Yahoo)
 Open Graph
Protocol
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Google Facebook
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48. Who does the Semantic Web?
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Thousands of datasets
Some offered in RDF
Linked by Linking Open
Government Data project
(200 datasets)
Open Government
Partnership (50+
countries)
 Gene research
 Language
processing
 Semantic MediaWiki
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Government/public data Academic work
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49. Where to learn in person?
 Semantic Technology & Business Conference
 Berlin, London, New York, San Francisco
 European Semantic Web Symposium
 International Semantic Web Conference
 International World Wide Web Conference
 International Conference on Semantic Web
and Web Services
 Semantic Web Applications and Tools for Life
Sciences
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50. Some interesting links...
 http://semanticweb.com/
 http://patterns.dataincubator.org/book/
 http://www.w3.org/standards/semanticweb/
 http://spinrdf.org
 Wikipedia
 http://semanticweb.com/breaking-into-the-nosql-conversation_b27146
 http://gigaom.com/2012/03/11/is-big-data-new-or-have-we-forgotten-its-old-
heroes/
 http://www.snee.com/bobdc.blog/2012/10/sparql-and-big-data-and-
nosql.html
 http://dret.net/netdret/docs/soa-rest-www2009/rest
 http://www.mkbergman.com/
 http://www.cambridgesemantics.com/semantic-university
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51. ...and some books
 David Wood, Linked Data, Manning
 Bob DuCharme, Learning SPARQL, O’Reilly
 Toby Segaran, Programming the Semantic Web, O’Reilly
 John Hebeler, Semantic Web Programming, Wiley
 David Siegel, Pull: The Power of the Semantic Web to Transform Your
Business, Portfolio
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