Web Services for Semantic Interoperability and Integration

1
Web Services for Semantic Interoperability and
Integration

• Tim Finin
• University of Maryland, Baltimore County
• Dagstuhl, 20 September 2004
• http//ebiquity.umbc.edu/v2.1/event/html/id/??/
• Joint work with many colleagues and students.
• ? http//creativecommons.org/licenses/by-nc-sa/2.0
  /
• This work was partially supported by DARPA
  contract F30602-97-1-0215, NSF grants CCR007080
  and IIS9875433 and grants from IBM, Fujitsu and
  HP.

2
Overview

• The question
• What role will web services play in support of
  semantic interoperability and integration (SII) ?
• My answer
• Illustration using two examples drawn from our
  work

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My Answer

• (1) Agents fill many useful roles for SII
• (2) On the web, web services play the role of
  agents
• (3) The web is consuming all IT
• (4) Therefore web services will replace agents in
  systems doing SII

4
Agents are useful for SSI

• Agents are ltinsert your favorite definition heregt
• Agent roles for SII include
• Discovery of ontologies, terms (e.g., class,
  property), and individuals
• Translation services
• Dynamic computing alignments and matches
• Meaning negotiation
• Reasoning services

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web services ? agents

• On the web, theres pressure to push all programs
  behind web service APIs
• It doesnt make much difference if agents
  communicate via KQMLKIF, FIPA, or OWLweb
  services
• We want to be at a level of abstraction involving
  beliefs, desires, intentions, plans, goals, etc.
• SO, if the price of admission is to use SOAP and
  WSDL, well pay it

6
The Web

• Is like the Blob, consuming all in its path
• Resistance is futile
• More seriously
• it promotes sharing, building on others content,
  offering your content for building upon,
  decentralization, community development and
  evolution, common identifiers (URIs), has a
  working infrastructure, etc.
• These are significant advantages

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Example Security and Trust forSemantic Web
Services

• Semantic web services are web services described
  using OWL-S
• Policy-based security infrastructure
• Advantages of using policies
• Expressive -- can be over descriptionsof
  requester, service context
• Authorization Rules for access control
• Privacy Rules for protecting information
• Confidentiality Cryptographiccharacteristics of
  informationexchanged

Policies Semantic Web Services
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Example

• Mary is looking for a reservation service
• Functional service requirements
• foaf identity description
• Confidentiality policy
• BravoAir is a reservation service
• OWL-S description
• Authorization policy (e.g., Only users belonging
  to the same project as John can access the
  service)
• Privacy policy
• The CMU matchmaker is an agent that finds and
  recommends services

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Mary

• lt!-- Mary's FOAF description --gt
• ltfoafPerson rdfID"mary"gt
• ltfoafnamegtMary Smithlt/foafnamegt
• ltfoaftitlegtMslt/foaftitlegt
• ltfoaffirstNamegtMarylt/foaffirstNamegt
• ltfoafsurnamegtSmithlt/foafsurnamegt
• ltfoafhomepage rdfresource"http//www.somewebsi
  te.com/marysmith.html"/gt
• ltfoafcurrentProject rdfresource"
  http//www.somewebsite.com/SWS-Project.rdf "/gt
• ltswspolicyEnforced rdfresource"maryConfident
  alityPolicy"/gt
• lt/foafPersongt
• lt/rdfRDFgt

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Bravo Policy

• ltentityVariable rdfabout"bravo-policyvar1"/gt
• ltentityVariable rdfabout"bravo-policyvar2"/gt
• ltconstraintSimpleConstraint
• rdfabout"bravo-policyGetJohnProject"
• constraintsubject"johnJohn"
• constraintpredicate"foafcurrentProject"
• constraintobject"bravo-policyvar2"/gt
• ltconstraintSimpleConstraint
• rdfabout"bravo-policySameProjectAsJohn"
• constraintsubject"bravo-policyvar1"
• constraintpredicate"foafcurrentProject"
• constraintobject"bravo-policyvar2"/gt
• lt!-- constraints combined --gt
• ltconstraintAnd rdfabout"bravo-policyAndCondit
  ion1"
• constraintfirst"bravo-policyGetJohnPro
  ject"
• constraintsecond"bravo-policySameProje
  ctAsJohn"/gt

• ltdeonticRight rdfabout"bravo-policyAccessRigh
  t"gt
• ltdeonticactor rdfresource"bravo-policyvar1"/
  gt
• ltdeonticaction rdfresource"bravo-serviceBrav
  oAir_ReservationAgent"/gt
• ltdeonticconstraint rdfresource"bravo-policyA
  ndCondition1"/gt
• lt/deonticRightgt
• ltrdfDescription rdfabout"bravo-serviceBravoAi
  r_ReservationAgent"gt
• ltswspolicyEnforced rdfresource"bravo-policyA
  uthPolicy"/gt
• lt/rdfDescriptiongt

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How it works
Matchmakerand Reasoner
BravoAirWeb service
Mary
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How it works
Marys query Bravo Service ? YES
Extract Bravos policy
Does Mary meets Bravos policy ?

• ltdeonticRight rdfabout"bravo-policyAccessRigh
  t"gt
• ltdeonticactor rdfresource"bravo-policyvar1"/
  gt
• ltdeonticaction rdfresource"bravo-serviceBrav
  oAir_ReservationAgent"/gt
• ltdeonticconstraint rdfresource"bravo-policyA
  ndCondition1"/gt
• lt/deonticRightgt
• ltpolicyGranting rdfabout"bravo-policyAuthGran
  ting"gt
• ltpolicyto rdfresource"bravo-policyvar1"/gt
• ltpolicydeontic rdfresource"bravo-policyAcces
  sRight"/gt
• lt/policyGrantinggt
• ltswsAuthorizationPolicy rdfabout"bravo-policy
  AuthPolicy"gt
• ltpolicygrants rdfresource"bravo-policyAuthGr
  anting"/gt
• lt/swsAuthorizationPolicygt
• ltrdfDescription rdfabout"bravo-serviceBravoAi
  r_ReservationAgent"gt
• ltswspolicyEnforced rdfresource"bravo-policyA
  uthPolicy"/gt
• lt/rdfDescriptiongt

Authorization enforcement complete
ltconstraintSimpleConstraint rdfabout
"bravo-policyGetJohnProject
constraintsubject"johnJohn"
constraintpredicate"foafcurrentProject"
constraintobject"bravo-policyvar2"/gt var2
http//www.somewebsite.com/SWS-Project.rdf
BravoAirWeb service
Mary
ltfoafcurrentProject rdfresource
"http//www.somewebsite.com/SWS-Project.rdf"/gt
ltconstraintSimpleConstraint
rdfabout"bravo-policySameProjectAsJohn"
constraintsubject"bravo-policyvar1"
constraintpredicate"foafcurrentProject"
constraintobject"bravo-policyvar2"/gt Is the
constraint true when var2 http//www.somewebsit
e.com/SWS-Project.rdfvar1 http//www.cs.umbc.ed
u/lkagal1/rei/examples/sws-sec/MaryProfile.rdf
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Google has made us smarter

• Google has made people smarter
• Software agents need something similar to
  maximizetheir use of information on the semantic
  web.

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Swoogle Google for SWDs
Current Status 190K SW documents 1
ontologies 33M triples 60K classes 50K
properties 5M values
http//swoogle.umbc.edu/

• Swoogle may provide the corpus of ontologies and
  data that use them desired by Natasha e.g.,
  answering queries like
• Find all documents that map between O1 and O2
• What classes are owlsameAs C
• What values are used for properties P1 and P2?
• Find all OWL-S service instances

Swoogle is a crawler based search retrieval
system for semantic web documents. It discovers
them, builds a DB of metadata relations, stores
them in a triple store and their source in an IR
system.
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(No Transcript)
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The Celebrity Couple
Semantic Web
Software Agents
In 2001, Geek Gossip gushed The semantic web
will provide content for internet agents, and
agents will make the semantic web come alive.
Looks like a match made in Heaven!
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Love is Fickle
Semantic Web
WebServices
In 2003, the Semantic web was seen everywhere in
the company of a new friend , web services.
Software agents was recently arrested for DUI and
assaulting a police officer.
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Example policies

• Authorization
• Policy 1 Stock service not accessible after
  market closes
• Policy 2 Only LAIT lab members who are Ph.D.
  students can use the LAIT lab laser printer
• Privacy/Confidentiality
• Policy 3 Do not disclose my my SSN
• Policy 4 Do not disclose my home address or
  facts from which it could be easily discovered
• Policy 5 Do not use a service that doesnt
  encrypt all input/output
• Policy 6 Use only those services that required
  an SSN if it is encrypted

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Swoogle2 Architecture
SWOOGLE 2
Human users
Web Server
SwoogleStatistics
OntologyDictionary
SwoogleSearch
service
Intelligent Agents
Web Service
IR analyzer
SWD analyzer
analysis
SWD Metadata
SWD Cache
digest
SWD Reader
The Web
Candidate URLs
discovery
Web Crawlers