Annotating Web Services for eGovernment Domain

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Annotating Web Services for eGovernment Domain
eGovernment Interoperability Campus 2007 10 11
October 2007 - Paris (France)
Luis Álvarez Sabucedo and Luis Anido
Rifón Universidade de Vigo España
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Agenda

• Introduction
• Semantic Web
• Proposal
• Semantics in use
• SWS applied
• Conclusion

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Agenda

• Introduction
• Semantic Web
• Proposal
• Semantics in use
• SWS applied
• Conclusion

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Introduction

• eGovernment ,the administration of the digital
  era
• the use of information and communication
  technology (ICT) and its application by the
  government for the provision of information and
  basic public services to the people
• National projects SAGA, eGIF, ADEA, FEAF,
• European projects Terregov, Ontogov, QUALEG,..
• Different bodies NSF, OASIS, OMG, CEN,

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Introduction

• Drawbacks
• Lack of interoperability among developed
  solutions
• Difficulties for locating services
• Our proposal
• Support the publication and discovery of services
• Take advantage of semantic technologies

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Agenda

• Introduction
• Semantic Web
• Proposal
• Semantics in use
• SWS applied
• Conclusion

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Semantics

• is an extension of the current web in which
  information is given well-defined meaning, better
  enabling computers and people to work in
  cooperation
• Tim Berners-Lee
• An ontology is a formal, explicit specification
  of a shared conceptualisation of a domain of
  interest.
• Gruber
• OWL, a W3C recomendation to express knowledge

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Semantic Web Services

• There is no consensus on the best approach to
  semantically describe Web Services.
• Current Approaches
• Use ontology-based mechanisms to describe web
  services OWL-S, WSMO,
• Mark up WSDL (now WSDSL 2.0!) with ontologies
  WSDL-S, SAWSDL
• Objective provide agents with additional
  capability

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Agenda

• Introduction
• Semantic Web
• Proposal
• Semantics in use
• SWS applied
• Conclusion

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Proposal

• Current services in the eGov domain offer little
  reuse and interoperability capablities. Their
  semantic description may overcome this situation.
• Requirement current eGov applications and tools
  should need little reengineering.
• Key concept Life Events. We will use this
  concept as the core for the rest of the proposal

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LifeEvent

• any particular situation in which a citizen must
  deal with a PA and he/she requires support or
  license from one o several PAs
• getting certifications, paying a fine, getting
  married, moving, requesting a grant from the
  government,

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LifeEvent
Luis Álvarez Luis Anido
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LifeEvent
Luis Álvarez Luis Anido
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LifeEvent

• Taking moving as an example
• Problem identification change the permanent
  address of a familiy
• Problem decomposition notify the local city
  councils (origin and destination), change school
  for children, medical insurance, notify banks and
  other for postal address change, etc.
• Look for the main terms documents requested to
  perform the operation (e.g. certification of the
  current address, renting contract for the new
  address, etc.)

Luis Álvarez Luis Anido
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LifeEvent

• Taking moving as an example
• Identify internal sub-goals Every operation that
  may be needed for the administration but which is
  not relevant for the citizen. E.g. notify address
  change to all departments in the administration
  tax office, police department, etc.
• Target document identification Certification of
  the new address, transport bonuses for children,
  new medical card, etc.
• Life Events rely on input documents and output
  documents hiding all needed internal operations
  and involved administrations to the citizen.

Luis Álvarez Luis Anido
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LifeEvent

• Objective provide a uniform view of the services
  provided by the administration to the citizen.
• We need a software architecture to support them.
• Web services are an obvious approach
• Their semantic support may increase
  interoperability

Luis Álvarez Luis Anido
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Agenda

• Introduction
• Semantic Web
• Proposal
• Semantics in use
• SWS applied
• Conclusion

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Semantic Support

• LEs are semantically described using OWL. This
  process was carried out following the
  Methontology guidelines.
• Apart from Life Events, the ontology includes
• Citizen the target user
• Public Administration the provider
• Document the tool for interacting with the
  administration
• Recommendations by official standardization
  bodies has been used CWA guidance on the use of
  Metadata in E-government Time ontology by the
  W3C, ISO standards

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LifeEvent - Ontology
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LifeEvent - Ontology
Several properties have been identified to allow
the implementation of mechanisms to discover
LifeEvents or how they can be composed. In
verse Relations can be defined e.g. is
supported
Luis Álvarez Luis Anido
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LifeEvent - Ontology
This rule states that each LE is
supported by a Public Administration.
Luis Álvarez Luis Anido
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LifeEvent - Ontology
This rule states that each LE generates
at least one document as output.
Luis Álvarez Luis Anido
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Publishing LEs

• Key point how do PAs publish their supported
  LEs?
• Two options
• Push method PAs will be responsible for that
• Pull method the system will look for LEs at
  the PAs sites.
• For the first option, we propose the use of the
  Blue Page Server which may be seen as the UDDI
  server in SOA

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Blue Page Server
Luis Álvarez Luis Anido
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Blue Page Server PA
Luis Álvarez Luis Anido
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Blue Page Server - PA

• Pull method use of the classic semantic web
• A crawler agent recovers them
• Security concerns again!
• Exploration just in eGov sites

ltlink rel"meta" type"application/rdfxml"
title"Moving to a new city" href"LEMoving.owl"
/gt
Luis Álvarez Luis Anido
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Agenda

• Introduction
• Semantic Web
• Proposal
• Semantics in use
• SWS applied
• Conclusion

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Semantic Support

• Next step support the access and use of LEs in
  terms of their execution by a software agent.
• Chosen technology WSDL-S
• Very simple
• Enough support for our needs
• Quite direct link from the provided OWL
• Based on
• Input/Output documents
• Precondition/postconditions

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WSDL-S

• We reuse the LE ontology for tagging the services
• Headings

ltdefinitions name "PayFine targetNamespace
"http//services.uvigo.es/LERepository/Services1B.
wsdl" xmlns "http//www.w3.org/2004/03/wsdl"
. xmlnspledge "http//pledge.det.uvigo.es/
plegde.owl" xmlnsmephttp//www.w3.org/TR/wsdl2
0-patternsgt
Luis Álvarez Luis Anido
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WSDL-S
ltoperation name "LEPayingFine" pattern
"mepin-out"gt ltinput messageLabel"LERequest"
element"pledgeFine" /gt ltinput
messageLabel"LERequest" element"pledgeDrivingLi
cense" /gt ltinput messageLabel"LERequest"
element"pledgeFiscalData" /gt ltoutput
messageLabel"LEResponse" element"pledgeFineRece
ipt"/gt lt/operationgt
Luis Álvarez Luis Anido
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Orchestration and choreography

• Information for choreography, on the WSDL-S file
• Each parameter is clearly tagged
• Orchestration requires complex tecniques to
  discover the right sequence of invocation.
• LEs may have pre-conditions that drive the
  appropriate sequence.
• The top (final) LE is the target
• To discover them Breath-First and Depth-First

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Orchestration and choreography
1
Final LE
Depth - First
2
5
Auxiliar LE
Auxiliar LE
3
4
7
6
Auxiliar LE
Auxiliar LE
Auxiliar LE
Auxiliar LE
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Agenda

• Introduction
• Semantic Web
• Proposal
• Semantics in use
• SWS applied
• Conclusion

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Conclusions

• Defining LE using OWLWSDL-S seems a feasible
  approach
• Semantic technologies are not mature enough to
  provide straightforward implemenations.
• Making things easier for PA and citizens is a
  must
• SWS may increase the possibilities to discover
  actual interoperable services in the eGov domain

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Conclusions

• Open issues
• Who will maintain the Life Event repository?
• Target administrations, some entity legally
  authorised?
• Legal support
• Open source mandatory?
• Migrating to SAWSDL?

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Thank you!!
Luis Álvarez Sabucedo and Luis Anido
Rifón Universidade de Vigo, SPAIN Luis.Anido_at_det.u
vigo.es