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Introducing the Semantic Web

MiND. Introducing the Semantic Web. Professor James Hendler http://www.cs.umd.edu/~hendler Co-Director, Maryland Information and Network Dynamics Laboratory Semantic Web Agents Project http://www.mindswap.org. Web of Knowledge. Proof, Logic and Ontology Languages.

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Introducing the Semantic Web

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  1. MiND Introducing the Semantic Web Professor James Hendlerhttp://www.cs.umd.edu/~hendler Co-Director, Maryland Information and Network Dynamics Laboratory Semantic Web Agents Project http://www.mindswap.org

  2. Web of Knowledge Proof, Logic and Ontology Languages Shared terms/terminology Machine-Machine communication 2010 Resource Description Framework eXtensible Markup Language Self-Describing Documents 2000 HyperText Markup Language HyperText Transfer Protocol Foundation of the Current Web 1990 Berners-Lee, Hendler; Nature, 2001 The Evolving Web DATA/PROGRAMS DOCUMENTS

  3. Web Semantics Semantic Web LayerCake (Berners-Lee, 99;Swartz-Hendler, 2001)

  4. Can’t we just use XML? This is what a web-page in natural language looks like for a machine

  5. < > name < > education < > CV < > work < > private XML helps XML allows “meaningful tags” to be added toparts of the text

  6. < > < name > name <education> < > education < CV > < > CV <work> < > work <private> < > private XML machine accessible meaning But to your machine, the tags look like this….

  7. Schemas take a step in the right direction Schemas help…. < CV > …by relating common termsbetween documents private

  8. < > name < > education < > CV < > work < > private But other people use other schemas Someone else has one like this…. name> <educ> < CV > <> <>

  9. The “semantics” isn’t there < CV > …which don’t fit in private

  10. < > < > name name < > < > education educ CV < > < > CV <> < > work < > < > private ‹›„⁄ KR provides “external” referents to merge on nme CV CV work vate CV educ educ SW languages add mappings And structure.

  11. Which is what the web was meant to be!! • "This is a pity, as in fact documents on the web describe real objects and imaginary concepts, and give particular relationships between them... For example, a document might describe a person. The title document to a house describes a house and also the ownership relation with a person. ... This means that machines, as well as people operating on the web of information, can do real things. For example, a program could search for a house and negotiate transfer of ownership of the house to a new owner. The land registry guarantees that the title actually represents reality.” • Tim Berners-Lee plenary presentation at WWW Geneva, 1994

  12. Putting semantics on the web

  13. (and making it machine-readable)

  14. Event:title <daml:ObjectProperty rdf:ID="photograph"> <rdfs:domain rdf:resource="#Picture"/> <rdfs:range rdf:resource= …#person"/> </daml:ObjectProperty> Event:WebPage < > rdf:type photo:Photograph, Photo:File http://…/images#image1, Photo:topic :event1#event:speaker. Event1 a Event:event; date “May 7-11”, speaker http://…#timbl.html Title “WWW 2002…” TimBL rdf:type w3c-ont:person; name “Tim Berners-Lee” … <s:Class rdf:about="http://www.semanticweb.org/ontologies/swrc-onto-2000-09-10.daml#Conference"> <s:comment> describes a generic conceptabout events </s:comment> <s:subClassOf rdf:resource="http://www.semanticweb.org/ontologies/swrc-onto-2000-09-10.daml#Event"/> <a:disjointFrom rdf:resource="http://www.semanticweb.org/ontologies/swrc-onto-2000-09-10.daml#Workshop"/> <a:restrictedBy rdf:resource="http://www.semanticweb.org/ontologies/swrc-onto-2000-09-10.daml#genid18"/> <rdf:Description rdf:about="http://www.w3.org/2001/03/earl/0.95#Person"> <rdf:type rdf:resource="http://www.w3.org/2000/01/rdf-schema#Class"/> <rdfs:subClassOf rdf:resource="http://www.w3.org/2001/03/earl/0.95#Assertor"/> </rdf:Description>

  15. On the Semantic WEB -- links are critical! URI URI URI RDF RDF is like the web! And… On the Web -- links are critical! Web page Any Web Resource <a href= URI> HTML <a href=“http://…”>

  16. RDF graphs resemble semantic nets DOC1 <mind:Person rdf:id=“Hendler”> <mind:title jobs:Professor> <jobs:placeOfWork http://www.cs.umd.edu> </mind:Person> Mind: Jobs: Professor DOC1 Mind:title Hendler Jobs: Web Page http://www… Jobs:placeOfWork

  17. Semantics on the WEB • RDF, like the WWW itself, is not “separable” • Thinking about the ontologies, without considering • The links to other terms • The instances that link to them • The crawling and collecting of ontological terminologues Is like thinking about the Web without the links!! OtherProfessors Othertitles OtherPages Mind: Jobs: Professor OtherURIs DOC1 Mind:title Hendler Jobs: Web Page http://www… Jobs:placeOfWork Otherdescriptions

  18. uses uses uses uses uses uses uses uses uses uses uses uses uses uses uses uses uses uses uses uses uses uses uses uses uses uses uses uses uses uses uses uses uses uses uses uses uses uses uses uses uses uses uses uses uses uses uses uses Radically new view of Semantics = some partial mapping Distributed,partially mapped, inconsistent -- but SCALEABLE!

  19. Real examples • Examples from http://dormouse.cs.umd.edu:8080/wiki/cmsc498wiki.wiki • Students violated every rule in the KR book • Extended existing ontologies • Linked instances directly to terms from multiple ontologies • Mixed “real KR” and NL • We can learn from their lessons • http://dormouse.cs.umd.edu:8080/wiki/assignment1_collected_les.wiki

  20. Youarehere Current Activities Semantic Web LayerCake (Berners-Lee, 99;Swartz-Hendler, 2001)

  21. W3C Web Ontology Working Group • Web Ontology Working Group in the W3C Semantic Web Activity aimed at “extending the semantic reach of current XML and RDF meta-data efforts. “ • History • DAML+OIL is submitted as a joint committee effort published as a W3C note . • W3C WG Announcement in November 2001 - http://lists.w3.org/Archives/Public/www-rdf-logic/2001Nov/0000.html • Weekly teleconferences started in November 2001 • First Face to Face Meeting - New Jersey (Lucent), Jan ‘02; 2nd - Amsterdam April (W3C); 3rd - CA (Fujitsu/Stanford host) July; 4th in Bristol UK (HP Host) Oct. • Four Working Drafts to date • Requirements/Use cases - March 2002 • 3 Technical Documents - July 2002 (Language renamed OWL)

  22. Membership • Current Working Group includes over 50 members from over 30 organizations. • Chairs • J. Hendler, MIND Lab UMCP • G. Schreiber, Univ. of Amsterdam • Industry including: • Large companies - Daimler Chrysler, IBM, HP, Intel, EDS, Fujitsu, Lucent, Motorola, Nokia, Philips Electronics, Sun, Unisys • Newer/smaller companies - IVIS Group, Network Inference, Stilo Technology, Unicorn Solutions • Government and Not-For-Profits: • US Defense Information Systems Agency, Interoperability Technology Association for Information Processing, Japan (INTAP) , Electricite De France, Mitre, NIST • Universities and Research Centers: • University of Bristol, University of Maryland, University of Southamptom, Stanford University • DFKI (German Research Center for Artificial Intelligence), Forschungszentrum Informatik, Ontoweb • Invited Experts • Well-known academics from non-W3C members (Hayes, Heflin, Stein, Borden)

  23. But will it fly? • DAML+OIL is already the most used ontology language ever!! • http://www.daml.org (3.5M statements on 25,000 web pages) • Gaining acceptance by web players • Semantic Web Track being offered at WWW 2002 • 3x more people attended WWW2002 Developer Day on SW than attended KR • Significant (international) Govt Support • US DARPA/NSF; EU IST Framework 5,6 • Japan, Germany, Australia considering significant investments • US National Cancer Institute to publish cancer vocabulary in DAML+OIL • Much New Startup activity (even in this economic climate) • Many tools being developed • Many of them aimed at developers, not just AI literate types

  24. Making Markup Easier

  25. Machine worries about the syntax

  26. Use that markup in query/portal interfaces

  27. Extending ontologies on the fly

  28. Semantic Web Portals: The Mosaic of the semantic web? <XSLT/> <Oncogene rdf:ID="Oncogene, MYB"><code>C3682</code><id>3683</id> <Found_In_Organism rdf:ID="Human"></Found_In_Organism> <Gene_Has_Function rdf:ID="Gene Transcription"></Gene_Has_Function> <Gene_Has_Function rdf:ID="Transcriptional Regulation"></Gene_Has_Function> <In_Chromosomal_Location rdf:ID="6q22-q23"/> </Oncogene> <Oncogene rdf:ID="Oncogene NMYC"> <code>C17656</code><id>17657</id><Found_In_Organism rdf:ID="Human"></Found_In_Organism> <In_Chromosomal_Location rdf:ID="2p24.1"/> <Gene_Has_Function rdf:ID="Transcriptional Regulation"> </Gene_Has_Function><Gene_Associated_With_Disease rdf:ID="Neuroblastoma"> </Gene_Associated_With_Disease></Oncogene>

  29. Moving to the futureof the web Semantic Web LayerCake (Berners-Lee, 99;Swartz-Hendler, 2001)

  30. Web “travel agents” How many cows are there in Texas? Query processed: 73 answers found • Google document search finds 235,312 possible page hits. • Http://www…/CowTexas.html claims the answer is 289,921,836 • A database entitled “Texas Cattle Association” can be queried for the answer, but you will need “authorization as a state employee.” • A computer program that can compute that number is offered by the State of Texas Cattleman’s Cooperative, click here to run program. • ... • The “sex network” can answer anything that troubles you, click here for relief... • The “UFO network” claims the “all cows in Texas have been replaced by aliens

  31. Allows new capabilities

  32. Services off the desktop

  33. Or perhaps on different desktops…

  34. Web Agents need Service Descriptions

  35. Semantic Web Service Description

  36. Use Semantics for Composition Translate my symptoms fromFrench and find me a pharmacythat has the necessary medicine(then compute how to get thereand print the directions) Print the directions to a pharmacywhich has a medicine that curesthe symptoms that I will tell you (in French)

  37. Or, translate to Planning Operators

  38. For goal-based service composition Buy the French version of a book from amazon.fr and have it sent to Mom’s address

  39. Services need Web Logics

  40. Web of Trust • Claims can be verified if there is supporting evidence from another (trusted) source • We only believe that someone is a professor at a university if the university also claims that person is a professor, and the university is on a list I trust. believe(c1) :- claims(x, c1) ^ predicate(c1, professorAt) ^ arg1(c1, x) ^ arg2(c1, y) ^ claims(c2, y) ^ predicate(c2, professorAt) ^ arg1(c2, x) ^ arg2(c2, y) ^ AccreditedUniversity(y) AcknowledgedUniversity(u) :- link-from(“http://www.cs.umd.edu/university-list”,u) Notice this one

  41. Distributed Trust

  42. Conclusion • It is no longer a question of whether the semantic web will come into being, it is already here! • We’re already well past the starting gate • Web ontologies, term languages, “shims” to DB and services, research in proofs/rules/trust • Standardization providing a common denominator for KR researchers as well as web developers • Small companies starting to form, Big companies starting to move • The current environment is open, encouraging, moving fast, and exciting as heck • Come play! http://www.daml.org http://www.semanticweb.org http://www.w3.org/2001/sw

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