OWLS: Semantic Markup for Web Services

1
OWL-S Semantic Markup for Web Services

• CSE 565
• Weilong Hu

2
OWL-S

• What is OWL-S?
• Why OWL-S?
• Compositions of OWL-S
• OWL-S and WSDL
• References

3
What is OWL-S?

• What is OWL?
• Ontology Web Language
• OWL-S is a OWL-based Web service ontology, which
  supplies Web service providers with a core set of
  markup language constructs for describing the
  properties and capabilities of their Web services
  in unambiguous, computer-intepretable form.

4
Why OWL-S?

• Automatic Web service discovery
• Automatic Web service invocation
• Automatic Web service composition and
  interoperation
• Automatic Web service execution monitoring

5
Compositions of OWL-S

• Profile
• Advertising and discovering services
• Process model
• Giving a detailed description of a services
  operation
• Grounding
• Providing details on how to interoperate with a
  service, via messages

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Examples

• Profile
• ltrdfRDF xmlnsrdf"http//www.w3.org/1999/02/22-r
  df-syntax-ns" xmlnsrdfs"http//www.w3.org/2000/
  01/rdf-schema" xmlnsowl"http//www.w3.org/2002/
  07/owl" xmlnsactor"http//www.daml.org/services
  /owl-s/1.0/ActorDefault.owl" xmlnsservice"http
  //www.daml.org/services/owl-s/1.0/Service.owl"
  xmlnsprocess"http//www.daml.org/services/owl-s/
  1.0/Process.owl" xmlnsprofile"http//www.daml.o
  rg/services/owl-s/1.0/Profile.owl"
  xmlnsprofileHierarchy"http//www.daml.org/servic
  es/owl-s/1.0/ProfileHierarchy.owl"
  xmlnsxsd"http//www.w3.org/2001/XMLSchema"
  xmlnscongoService"http//www.daml.org/services/o
  wl-s/1.0/CongoService.owl" xmlnscongoProcess"ht
  tp//www.daml.org/services/owl-s/1.0/CongoProcess.
  owl" xmlns"http//www.daml.org/services/owl-s/1.
  0/CongoProfile.owl"gt
• - ltowlOntology rdfabout""gt
•   ltowlversionInfogtId CongoProfile.owl,v 1.31
  2003/12/20 040421 martin Exp lt/owlversionInfogt
  
•   ltrdfscommentgtOWL-S Coalition CongoBuy Example
  for OWL-S release 1.0lt/rdfscommentgt
•   ltowlimports rdfresource"http//www.daml.org/s
  ervices/owl-s/1.0/Service.owl" /gt
•   ltowlimports rdfresource"http//www.daml.org/s
  ervices/owl-s/1.0/Process.owl" /gt
•   ltowlimports rdfresource"http//www.daml.org/s
  ervices/owl-s/1.0/Profile.owl" /gt
•   ltowlimports rdfresource"http//www.daml.org/s
  ervices/owl-s/1.0/CongoService.owl" /gt
•   ltowlimports rdfresource"http//www.daml.org/s
  ervices/owl-s/1.0/CongoProcess.owl" /gt
•   ltowlimports rdfresource"http//www.daml.org/s
  ervices/owl-s/1.0/Concepts.owl" /gt
•   ltowlimports rdfresource"http//www.ai.sri.com
  /daml/ontologies/time/Time.owl" /gt
•   ltowlimports rdfresource"http//www.daml.org/s
  ervices/owl-s/1.0/ProfileHierarchy.owl" /gt
•   lt/owlOntologygt

7
Example

• Process model
• lt?xml version"1.0" encoding"ISO-8859-1" ?gt
•   lt!DOCTYPE uridef (View Source for full
  doctype...)gt
• - ltrdfRDF xmlnsrdf"http//www.w3.org/1999/02/22
  -rdf-syntax-ns" xmlnsrdfs"http//www.w3.org/200
  0/01/rdf-schema" xmlnsxsd"http//www.w3.org/200
  1/XMLSchema" xmlnsowl"http//www.w3.org/2002/07
  /owl" xmlnscongodf"http//www.daml.org/services
  /owl-s/1.0/CongoProcessDataFlow.owl"
  xmlnsservice"http//www.daml.org/services/owl-s/
  1.0/Service.owl" xmlnsprocess"http//www.daml.o
  rg/services/owl-s/1.0/Process.owl"
  xmlnstime"http//www.isi.edu/pan/damltime/time-
  entry.owl" xmlns"http//www.daml.org/services/ow
  l-s/1.0/CongoProcess.owl"gt
• - ltowlOntology rdfabout""gt
•   ltowlversionInfogtId CongoProcess.owl,v 1.48
  2004/03/30 072626 martin Exp lt/owlversionInfogt
  
•   ltrdfscommentgtA B2C bookbuying example of OWL-S
  (Web Ontology Language for Services see
  http//www.daml.org/services/) usage,
  illustrating a simple use of the process model.
  There are several other .owl files that
  instantiate the other areas of OWL-S (profile,
  grounding, and service declarations, as well as
  the process dataflow) for this same example.
  NOTE This is a sketch not a complete example.
  It is designed to illustrate the usage of the
  process model ontology. The service described
  here is a book buying (or selling, depending on
  your perspective) service from www.congo.com. We
  present two forms of the service. First, there's
  a one-step form, CongoBuy, with the service
  treated as ATOMIC i.e., no interactions between
  buying and selling agents are required, apart
  from invocation of the service and receipt of its
  outputs by the buyer. Given certain inputs and
  preconditions, the service provides certain
  outputs and has specific effects. Second, a
  full-fledged version of the service is specified,
  showing its composition from its component
  services. The full-fledged version of the
  service, FullCongoBuy, includes an arrangement of
  subprocesses LocateBook, PutInCart, SignIn,
  CreateAcct, CreateProfile, LoadProfile,
  SpecifyDeliveryDetails, FinalizeBuy each with its
  own specification of inputs and outputs. Note
  Input, output, precondition, and effect
  properties of composite processes can, in
  principle, be automatically generated by tools.
  Since such tools don't yet exist, they have been
  manually generated for this example. Original
  Congo example created by Srini Narayanan
  (srini_at_ai.sri.com). Major modifications by Mark
  Burstein, David Martin, Sheila McIlraith, Srini
  Narayanan, Terri Payne, Massimo Paolucci. Note
  Starting with version 1.0, OWL-S views processes
  as instances of the Process class rather than as
  subclasses of it.lt/rdfscommentgt
•   ltowlimports rdfresource"http//www.isi.edu/p
  an/damltime/time-entry.owl" /gt
•   ltowlimports rdfresource"http//www.daml.org/s
  ervices/owl-s/1.0/Service.owl" /gt
•   ltowlimports rdfresource"http//www.daml.org/s
  ervices/owl-s/1.0/Process.owl" /gt
•   ltowlimports rdfresource"http//www.daml.org/s
  ervices/owl-s/1.0/CongoProcessDataFlow.owl" /gt
•   lt/owlOntologygt
• - lt!--
  Some Basic Data Types
    --gt
• - ltowlClass rdfID"CreditCardType"gt
• - ltowloneOf rdfparseType"Collection"gt
•   ltCreditCardType rdfID"MasterCard" /gt
•   ltCreditCardType rdfID"VISA" /gt
•   ltCreditCardType rdfID"AmericanExpress" /gt
•   ltCreditCardType rdfID"DiscoverCard" /gt

8
Example

• Grounding
• lt?xml version"1.0" encoding"ISO-8859-1" ?gt
•   lt!DOCTYPE uridef (View Source for full
  doctype...)gt
• - ltrdfRDF xmlnsrdf"http//www.w3.org/1999/02/22
  -rdf-syntax-ns" xmlnsrdfs"http//www.w3.org/200
  0/01/rdf-schema" xmlnsowl"http//www.w3.org/200
  2/07/owl" xmlnsxsd"http//www.w3.org/2001/XMLSc
  hema" xmlnsservice"http//www.daml.org/services
  /owl-s/1.0/Service.owl" xmlnsgrounding"http//w
  ww.daml.org/services/owl-s/1.0/Grounding.owl"
  xmlnscongo_service"http//www.daml.org/services/
  owl-s/1.0/CongoService.owl" xmlns"http//www.dam
  l.org/services/owl-s/1.0/CongoGrounding.owl"gt
• - ltowlOntology rdfabout""gt
•   ltowlversionInfogtId CongoGrounding.owl,v 1.28
  2003/12/23 233905 martin Exp lt/owlversionInfogt
  
•   ltrdfscommentgtThis ontology represents the
  OWL-S service grounding for the Congo web service
  example.lt/rdfscommentgt
•   ltowlimports rdfresource"http//www.daml.org/s
  ervices/owl-s/1.0/Service.owl" /gt
•   ltowlimports rdfresource"http//www.daml.org/s
  ervices/owl-s/1.0/Process.owl" /gt
•   ltowlimports rdfresource"http//www.daml.org/s
  ervices/owl-s/1.0/Grounding.owl" /gt
•   ltowlimports rdfresource"http//www.daml.org/s
  ervices/owl-s/1.0/CongoProcess.owl" /gt
•   ltowlimports rdfresource"http//www.daml.org/s
  ervices/owl-s/1.0/CongoService.owl" /gt
•   lt/owlOntologygt
• - lt!--

9
OWL-S and WSDL

• On the one hand (the abstract side of a service
  specification), the developer benefits by making
  use of OWL-S' process model, and the
  expressiveness of OWL's class typing mechanisms,
  relative to what XML Schema Definition (XSD)
  provides.
• On the other hand (the concrete side), the
  developer benefits from the opportunity to reuse
  the extensive work done in WSDL (and related
  languages such as SOAP), and software support for
  message exchanges based on these declarations, as
  defined to date for various protocols and
  transport mechanisms.

10
OWL-S and WSDL

• OWL-S/WSDL grounding approach
• Limitation
• specify two or more possible sets of outputs
• WSDL 1.1 allows only a single output message
  specification for a given operation, and because
  OWL-S' treatment of conditional outputs is
  expected to evolve further

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References

• OWL-S Semantic Markup for Web Services
  http//www.daml.org/services/owl-s/1.0/owl-s.html
• OWL-S 1.0 Release http//www.daml.org/services/owl
  -s/1.0/
• DAML Services introduction http//www.daml.org/ser
  vices/owl-s/