The document provides an introduction to the Semantic Web, including: - The Semantic Web extends the current web by giving information well-defined meaning so computers and people can better work together. - It aims to make data easier for machines to publish, share, find and understand through smarter data rather than just smarter machines. - Examples of Semantic Web applications include Bio2RDF, which provides structured data about genes, and the BBC publishing semantic metadata about musical artists.

1. Semantic Web An Introduction Emanuele Della Valle [email_address] http://emanueledellavalle.org

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3. Agenda Dal Web delle origini al Semantic Web Introduzione al Semantic Web Applicazioni del Semantic Web Conclusione

4. Il Web delle origini 1988 (CERN)

5. Il Web delle origini (1990) [source: http://www.w3.org/DesignIssues/diagrams/history/proposal-fig1.gif ] [source: http://www.w3.org/DesignIssues/diagrams/history/Architecture_crop.png ]

6. The Web today Let’s browse together 2009 Map http://www.zoomorama.com/01-2477f0e8b447bb6570493cdac464c41f

7. Introduction Computer should understand more Large number of integrations - ad hoc - pair-wise Too much information to browse, need for searching and mashing up automatically Each site is “understandable” for us Computers don’t “understand” much ? Millions of Applications Search & Mash-up Engine 010 0 1 1 0 0 1101 10100 10 0010 01 101 101 01 110 1 10 1 10 0 1 1 0 1 0 1 0 0 1 1 0 1 1 1 10 0 1 101 0 1

8. Introduction What does “understand” mean? What we say to Web agents &quot; For more information visit <a href=“http://www.ex.org”> my company </a> Web site. . .” What they “hear” &quot; blah blah blah blah blah <a href=“http://www.ex.org”> blah blah blah </a> blah blah. . .” Jet this is enought to train them to achive tasks for us [ source http://www.thefarside.com/ ]

9. Introduction What does Google “understand”? Understanding that [page1] links [page2]  page2 is interesting Google is able to rank results! “ The heart of our software is PageRank™, a system for ranking web pages […] (that) relies on the uniquely democratic nature of the web by using its vast link structure as an indicator of an individual page's value .” http://www.google.com/technology/

10. Introduction Two ways for computer to “understand” Smarter machines Such as Natural Langue processing (NLP) Audio Processing Image Processing (IP) Video Processing … many many more They all work fine alone, the problem is combining them E.g., NLP meets IP NLP: What does your eye see? IP: I see a sea NLP: You see a “c”? IP: Yes, what else could it be? Not the Semantic Web approach Smarter Data Make data easier for machines to publish, share, find and understand E.g. http://wordnet.rkbexplorer.com/description/word-sea vs. http://wordnet.rkbexplorer.com/description/word-c The Semantic Web approach Some NLP Related Entertainment http://www.cl.cam.ac.uk/Research/ NL/amusement.html

11. Introduction The Semantic Web 1/4 “ The Semantic Web is not a separate Web, but an extension of the current one, in which information is given well-defined meaning, better enabling computers and people to work in cooperation.” “ The Semantic Web”, Scientific American Magazine, Maggio 2001 http://www.sciam.com/article.cfm?articleID=00048144-10D2-1C70-84A9809EC588EF21 Key concepts an extension of the current Web in which information is given well-defined meaning better enabling computers and people to work in cooperation. Both for computers and people

12. Introduction The Semantic Web 2/4 “ The Semantic Web is not a separate Web, but an extension of the current one […] ” Web 1.0 The Web Today

13. Introduction The Semantic Web 3/4 “ The Semantic Web […] , in which information is given well-defined meaning […]” Human understandable but “only” machine-readable Human and machine “ understandable ” ? Web 1.0 Semantic Web

14. Introduction The Semantic Web 4/4 Semantic Web Fewer Integration - standard - multi-lateral […] better enabling computers and people to work in cooperation. Even More Applications Easier to understand for people More “understandable” for computers Semantic Mash-ups & Search

15. Introduction Bio2RDF project - http://bio2rdf.org/

16. Introduction Bio2RDF REST services Describe a resource by a dereferencable URI http://bio2rdf.org/ns :id Global services over federated endpoints http://bio2rdf.org/links/ ns:id http://bio2rdf.org/search/ searchedTerm Targeted services to a specific endpoint http://bio2rdf.org/linksns/ ns2/ns1:id http://bio2rdf.org/searchns/ns/ searchedTerm

17. Introduction Example of questions Bio2RDF can answer What is known about human BRCA genes? http://bio2rdf.org/search/BRCA1 What is known about human BRCA genes in Entrez Gene databank (i.e., the Bio2RDF data source whose namespace is geneid)? http://bio2rdf.org/searchns/geneid/BRCA1 What can you tell me which fact are known about the human tumor suppressor gene BRCA1 (Gene ID: 672 )? http://bio2rdf.org/geneid:672 What information is linked to geneid:672? http://bio2rdf.org/links/geneid:672 Which is the FASTA sequence of the human 5-hydroxytryptamine receptor 2A (whose accession number is AB037513 ) in NCBI GeneBank databank (i.e., the Bio2RDF data source whose namespace is genbank). http://bio2rdf.org/fasta/genbank:AB03751 And the image? http://bio2rdf.org/image/genbank:AB037513

18. Introduction Complex Example: Linking Open Data Project Goal: extend the Web with data commons by publishing open data sets using Semantic Web techs Visit http://esw.w3.org/topic/SweoIG/TaskForces/CommunityProjects/LinkingOpenData ! Project Chartres RDFizers and ConverterToRdf Publishing Tools Semantic Web Browsers and Client Libraries Semantic Web Search Engines Applications […] Bio2RDF

19. Introduction Light Example: Publishing Semantic Mark-up A firefox plug-in such as Operator can extract those semantic mark-up from the page and offers actions such as “add the event to your calendar” https://addons.mozilla.org/en-US/firefox/addon/4106 <div id=&quot;event-info-where&quot; class=&quot;info-wh-info vcard &quot;> <h2><a rel=&quot;bookmark&quot; class=&quot;fn org location&quot; href=&quot;/venues/V0-001-000693919-2&quot;> Circus Krone Munich </a></h2> <div class=&quot;adr&quot; > <span class=&quot;street-address&quot; > 1 </span><br> <span class=&quot;locality&quot; > Munich </span>, <span class=&quot;region&quot; > Bayern </span> <br> <span class=&quot;country-name&quot; > Germany </span>

20. Introduction Example: BBC’s Artist as Linked Data <?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?> <rdf:RDF xmlns:rdf = &quot;http://www.w3.org/1999/02/22-rdf-syntax-ns#&quot; xmlns:rdfs = &quot;http://www.w3.org/2000/01/rdf-schema#&quot; xmlns:owl = &quot;http://www.w3.org/2002/07/owl#&quot; xmlns:dc = &quot;http://purl.org/dc/elements/1.1/&quot; xmlns:foaf = &quot;http://xmlns.com/foaf/0.1/&quot; xmlns:rel = &quot;http://www.perceive.net/schemas/relationship/&quot; xmlns:mo = &quot;http://purl.org/ontology/mo/&quot; xmlns:rev = &quot;http://purl.org/stuff/rev#&quot; > <rdf:Description rdf:about=&quot;/music/artists/a3cb23fc-acd3-4ce0-8f36-1e5aa6a18432.rdf&quot;> <rdfs:label>Description of the artist U2</rdfs:label> <foaf:primaryTopic rdf:resource=&quot;/music/artists/a3cb23fc-acd3-4ce0-8f36-1e5aa6a18432#artist&quot;/> </rdf:Description> <mo:MusicGroup rdf:about=&quot;/music/artists/a3cb23fc-acd3-4ce0-8f36-1e5aa6a18432#artist&quot;> <foaf:name>U2</foaf:name> <owl:sameAs rdf:resource=&quot;http://dbpedia.org/resource/U2&quot; /> <foaf:page rdf:resource=&quot;/music/artists/a3cb23fc-acd3-4ce0-8f36-1e5aa6a18432.html&quot; /> <mo:musicbrainz rdf:resource=&quot;http://musicbrainz.org/artist/a3cb23fc-acd3-4ce0-8f36-1e5aa6a18432.html&quot; /> <mo:homepage rdf:resource=&quot;http://www.u2.com/&quot; /> <mo:fanpage rdf:resource=&quot;http://www.atu2.com/&quot; /> <mo:wikipedia rdf:resource=&quot;http://en.wikipedia.org/wiki/U2&quot; /> <mo:imdb rdf:resource=&quot;http://www.imdb.com/name/nm1277752/&quot; /> <mo:myspace rdf:resource=&quot;http://www.myspace.com/u2&quot; /> <mo:member rdf:resource=&quot;/music/artists/7f347782-eb14-40c3-98e2-17b6e1bfe56c#artist&quot; /> <mo:member rdf:resource=&quot;/music/artists/1f52af22-0207-40ac-9a15-e5052bb670c2#artist&quot; /> HTML: http://www.bbc.co.uk/music/artists/a3cb23fc-acd3-4ce0-8f36-1e5aa6a18432 RDF : http://www.bbc.co.uk/music/artists/a3cb23fc-acd3-4ce0-8f36-1e5aa6a18432.rdf

21. Introduction New York Times Thesaurus For more than 150 years, The New York Times has meticulously indexed its archives. Through this process, we have developed an enormous collection of subject headings […]. Unfortunately, our list of subject headings is an island. For example, even though we can show you every article written about “Colbert, Stephen,” our databases can’t tell you that he was born on May 13, 1964, or that he lost the 2008 Grammy for best spoken word album to Al Gore . To do this we would need to map our subject headings onto other Web databases such as Freebase and DBPedia . So that’s exactly what we did. Over the last several months we have manually mapped more than 5,000 person name subject headings onto Freebase and DBPedia. […] So now you can visit http://data.nytimes.com/N66220017142656459133 and see that our “Colbert, Stephen” is equivalent to DBPedia’s http://dbpedia.org/resource/Stephen_Colbert and Freebase’s http://rdf.freebase.com/rdf/en.stephen_colbert . Even more importantly, your computer can visit http://data.nytimes.com/N66220017142656459133.rdf and get all of this information in a computer-readable (RDF) document. October 29, 2009, 4:07 pm First 5,000 Tags Released to the Linked Data Cloud By EVAN SANDHAUS AND ROB LARSON

22. Introduction Browsing the LOD with http://sig.ma/ Try it! http://sig.ma/search?q=Propranolol

23. Introduction The new era of Semantic Apps One of the highlights of October's Web 2.0 Summit in San Francisco was the emergence of 'Semantic Apps' as a force. The purpose of this post is to highlight 10 Semantic Apps. […] It reflects the nascent status of this sector, even though people like Hillis and Spivack have been working on their apps for years now. Read out more at http://www.readwriteweb.com/archives/10_semantic_apps_to_watch.php

24. Introduction Semantic Web “layer cake” Standardized Under Investigation Already Possible [ source http://www.w3.org/2007/03/layerCake.png ]

25. Introduction Architectural view of the lower layers [source http://www.w3.org/DesignIssues/diagrams/sw-double-bus.png ]

26. Credits Introduction and RDF slides are partially based on “Fundamentals of the Semantic Web” by David Booth http://www.w3.org/2002/Talks/0813-semweb-dbooth/