sweo talk
DESCRIPTION
TRANSCRIPT
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
3J. Hendler, 2002
The Evolving Web
Web ofKnowledge
HyperText Markup LanguageHyperText Transfer Protocol
Resource Description FrameworkeXtensible Markup Language Self-Describing Documents
Foundation of the Current Web
Proof, Logic andOntology Languages Shared terms/terminology
Machine-Machine communication
1990
2000
2010
Berners-Lee, Hendler; Nature, 2001
DOCUMENTS
DATA/PROGRAMS
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Web Semantics
Semantic Web LayerCake (Berners-Lee, 99;Swartz-Hendler, 2001)
Can’t we just use XML?
This is what a web-page in natural language looks like for a machine
XML helps
CV
name
education
work
private
< >
< >
< >
< >
< >
XML allows “meaningful tags” to be added toparts of the text
XML machine accessible meaning
CV
name
education
work
private
< >
< >
< >
< >
< >
< >
< >
<>
<>
<>
But to your machine, the tags look like this….
Schemas take a step in the right direction
Schemas help….
CV
name
education
work
private
< >
< >
< >
< >
< >
< >
<>
<>
<>
<>
CV
name
education
work
private
< >
< >
< >
< >
< >
< >
<>
<>
<>
<>
< > …by relating common termsbetween documents
But other people use other schemas
CV
name
education
work
private
< >
< >
< >
< >
< >
< >
>
<>
<>
Someone else has one like this….
The “semantics” isn’t there
CV
name
education
work
private
< >
< >
< >
< >
< >
< >
<>
<>
<>
<>
CV
name
education
work
private
< >
< >
< >
< >
< >
< >
<>
<>
<>
<>
< >…which don’t fit in
CV
name
education
work
private
< >
< >
< >
< >
< >
< CV >
<name >
<educ >
<>
<⇐∨ >
KR provides “external” referents to merge on
CV
name
education
work
private
< >
< >
< >
< >
< >
< >
<>
<>
<>
<>
CV
name
education
work
private
< >
< >
< >
< >
< >
< >
<>
<>
<>
<>
CV
name
education
work
private
< >
< >
< >
< >
< >
< >
<>
<>
<>
<>
SW languages add mappingsAnd structure.
CV
name
education
work
private
< >
< >
< >
< >
< >
< CV >
<name >
<educ >
<>
<⇐∨ >
CV
name
education
work
private
< >
< >
< >
< >
< >
< CV >
<name >
<educ >
<>
<⇐∨ >
CV
name
education
work
private
< >
< >
< >
< >
< >
< CV >
<name >
<educ >
<>
<⇐∨ >
CV
name
education
work
private
< >
< >
< >
< >
< >
< >
< >
< >
< ‹›„⁄ >
CV
name
education
work
private
< >
< >
< >
< >
< >
< CV >
<name >
<educ >
<>
<⇐∨ >
12J. Hendler, 2002
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
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Putting semantics on the web
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(and making it machine-readable)
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Event:title
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” …
<daml:ObjectProperty rdf:ID="photograph"><rdfs:domain rdf:resource="#Picture"/><rdfs:range rdf:resource= …#person"/></daml:ObjectProperty>
<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>
<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"/>
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On the Web -- links are critical!
<a href= URI>
HTML
Web page Any Web Resource
<a href=“http://…”>
RDF
URI URI
URI
RDF is like the web! And…
On the Semantic WEB -- links are critical!
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<mind:Person rdf:id=“Hendler”> <mind:title jobs:Professor> <jobs:placeOfWork http://www.cs.umd.edu></mind:Person>
DOC1
HendlerDOC1 Mind:title
Jobs:placeOfWork Web Pagehttp://www…
ProfessorJobs:Mind:
Jobs:
RDF graphs resemble semantic nets
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Semantics on the WEB
RDF, like the WWW itself, is not “separable” Thinking about the ontologies, without considering
The links to other termsThe instances that link to themThe crawling and collecting of ontological terminologues
Is like thinking about the Web without the links!!
HendlerDOC1 Mind:title
Jobs:placeOfWork Web Pagehttp://www…
ProfessorJobs:Mind:
Jobs:
OtherProfessors
OtherPages
Othertitles
Otherdescriptions
OtherURIs
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Radically new view of Semantics
Distributed,partially mapped, inconsistent -- but SCALEABLE!
uses
uses
uses
uses
usesuses
uses
uses
uses
uses
uses
uses
usesuses
uses
uses
uses
uses
uses
uses
usesuses
uses
uses
uses
uses
uses
uses
usesuses
uses
uses
uses
uses
uses
uses
usesuses
uses
uses
uses
uses
uses
uses
usesuses
uses
uses
= some partial mapping
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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
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Current Activities
Semantic Web LayerCake (Berners-Lee, 99;Swartz-Hendler, 2001)
Youarehere
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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 dateRequirements/Use cases - March 20023 Technical Documents - July 2002 (Language renamed OWL)
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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)
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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
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Making Markup Easier
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Machine worries about the syntax
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Use that markup in query/portal interfaces
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Extending ontologies on the fly
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Semantic Web Portals: The Mosaic of the semantic web?
<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>
<XSLT/>
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Moving to the futureof the web
Semantic Web LayerCake (Berners-Lee, 99;Swartz-Hendler, 2001)
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Web “travel agents”
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
How many cows are there in Texas?
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Allows new capabilities
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Services off the desktop
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Or perhaps on different desktops…
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Web Agents need Service Descriptions
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Semantic Web Service Description
- <daml:Class rdf:ID ="CreateAcct"> < rd fs :s ubC las sOf
rd f: re so u rce = "h tt p:/ / ww w. da m l.o rg / ser vi c e s/da ml-s/2001 / 10/ Proc ess .d am l#A tomi c Proc e s s " />
- < rd fs :s ubC las sOf >- < da m l: Re s t riction d a ml: ca rdi n ali ty = "1 ">
< da m l: on Pr ope rty rd f: re so u rce = "#c re a te Acc tI nf o " /> </ da m l: Re s t riction >
</ rd fs :s ubC las sOf >- < rd fs :s ubC las sOf >
- < da m l: Re s t riction d a ml: ca rdi n ali ty = "1 "> < da m l: on Pr ope rty rd f: re so u rce = "#c re a te Acc tOu tpu t " />
</ da m l: Re s t riction > </ rd fs :s ubC las sOf >
</ da m l:C las s >- < rd f: Pr op er ty rd f: ID = "c re a te Acct Inf o ">
< rd fs :s ub Pr ope rtyOfrd f: re so u rce = "h tt p:/ / ww w. da m l.o rg / ser vi c e s/da ml-s/2001 / 10/ Proc ess .d am l# in pu t " />
< rd fs : d omai n rd f: re so u rce = "# Cre at eA cct " /> < rd fs : ra n g e rd f: re so u rce = "# Acct Inf o " />
</ rd f: Pr op er ty>- < rd f: Pr op er ty rd f: ID = "c re a te Acct Ou tpu t ">
< rd fs :s ub Pr ope rtyOfrd f: re so u rce = "h tt p:/ / ww w. da m l.o rg / ser vi c e s/da ml-s/2001 / 10/ Proc ess .d am l#o u tpu t " />
< rd fs : d omai n rd f: re so u rce = "# Cre at eA cct " /> < rd fs : ra n g e rd f: re so u rce = "# Cre at eA cct Ou tpu tT ype " />
</ rd f: Pr op er ty>
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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)
39J. Hendler, 2002
Or, translate to Planning Operators
- <daml:Class rdf:ID ="DeliveryType">- <daml:oneOf rdf:parseType="daml:collection">
<DeliveryTy pe rdf:ID ="FedExOneDay" /> <DeliveryTy pe rdf:ID ="FedEx2-3day" /> <DeliveryTy pe rdf:ID ="UPS" /> <DeliveryTy pe rdf:ID ="OrdinaryMail" />
</daml:oneOf> </daml:Class>
The atomic process “SpecifyDeliveryDetails” can be translated into a SHOP2 operatorwith corresponding preconditions as follows:
( :o p era to r (! S pe ci fy Deli v e ry De tai ls ? deli v e ryAdd ress ?pa ck ag ing S ele ct io n ?del iv ery Type S ele ct ion )
((n ot ( sa m e ?del iv eryAdd ress ni l)) (n ot ( s a m e ? pa ck agi n g S ele ct io n nil ) ) (n ot ( s a m e ? deli v e ryTyp e S e le ct io n nil ) ) (e v a l ( s tringp ?del iv eryAdd ress) ) (e v a l ( m e m ber ‘? pa ck agi n g S ele ct io n ‘(Gif tw rap Ord ina ry)))
(e va l ( m e m be r ‘?del iv ery Type S ele ct io n ‘( Fe dE x On eD ay Fed Ex 2 -3da y U PS Ord inar y Ma il) ) ))
() ())
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For goal-based service composition
Buy the French version of a book from amazon.fr and have it sent to Mom’s address
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Services need Web Logics
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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
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Distributed Trust
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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!