Semantic Web Services: Approaches and...
Transcript of Semantic Web Services: Approaches and...
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
Semantic Web Services: Approaches and Applications
John DomingueKnowledge Media Institute,
The Open University
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
Some Slides Adapted from• Mary Rowlatt, Leticia Gutierrez
– Essex County Council• Amit Sheth
– Kno.e.sis Center, Wright State University• Kunal Verma
– Accenture Technology Labs• Jacek Kopecký
– STI Innsbruck• Stephan Haller
– SAP
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
Web Services
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
What’s a Web Service?
• A program programmatically accessible over standard internet protocols
• Loosely coupled, reusable components
• Encapsulate discrete functionality
• Distributed
• Add new level of functionality on top of the current web
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
Web Services Framework
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
GigaVox Architecture
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
ClickWorkers (1/2)
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
ClickWorkers (2/2)
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
Artificial Artificial Intelligence
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
Problems with Web Services Today
• Descriptions are syntactic• All tasks associated with web services
application development have to be carried out by humans:
– discovery, composition and invocation• Problems of scalability
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
SWS Vision
Web(URI, HTML, HTTP)
Web Services(UDDI, WSDL, SOAP)
Semantic Web(RDF, OWL)
Semantic Web Services
Dynamic
Static
Syntax Semantics
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
Semantic Web Services (is)• Semantic Web Technology
– Machine readable data– Ontological basis
Applied to
• Web Services Technology– Reusable computational resources
To automate all aspects of application development through reuse
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
Semantic Web Service Broker
Client
Services
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
Web Service Modelling Ontology (WSMO)
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
WSMO Top Level NotionsObjectives that a client wants toachieve by using Web Services
Provide the formally specified terminologyof the information used by all other components
Semantic description of Web Services: - Capability (functional)- Interfaces (usage)
Connectors between components with mediation facilities for handling heterogeneities
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
WSMO Top Level NotionsObjectives that a client wants toachieve by using Web Services
Provide the formally specified terminologyof the information used by all other components
Semantic description of Web Services: - Capability (functional)- Interfaces (usage)
Connectors between components with mediation facilities for handling heterogeneities
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
WSMO Top Level NotionsObjectives that a client wants toachieve by using Web Services
Provide the formally specified terminologyof the information used by all other components
Semantic description of Web Services: - Capability (functional)- Interfaces (usage)
Connectors between components with mediation facilities for handling heterogeneities
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
Goals
• Ontological De-coupling of Requester and Provider • Derived from task / problem solving methods/domain
model • Structure and reuse of requests
– Search– Diagnose– Classify– Personalise– Book a holiday
• Requests may in principle not be satisfiable• Ontological relationships & mediators used to link goals to
web services
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
WSMO Top Level NotionsObjectives that a client wants toachieve by using Web Services
Provide the formally specified terminologyof the information used by all other components
Semantic description of Web Services: - Capability (functional)- Interfaces (usage)
Connectors between components with mediation facilities for handling heterogeneities
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
WSMO Web Service Description
Web ServiceImplementation(not of interest in Web Service Description)
Choreography --- Service Interfaces ---
Capability
functional description
WS
WS
- Advertising of Web Service- Support for WS Discovery
client-service interaction interface for consuming WS - External Visible
Behavior- Communication
Structure- ‘Grounding’
realization of functionality by aggregating other Web Services - functional
decomposition - WS composition
Non-functional Properties
DC + QoS + Version + financial
- complete item description- quality aspects - Web Service Management
WS
Orchestration
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
WSMO Web Service Description
Web ServiceImplementation(not of interest in Web Service Description)
Choreography --- Service Interfaces ---
Capability
functional description
WS
WS
- Advertising of Web Service- Support for WS Discovery
client-service interaction interface for consuming WS - External Visible
Behavior- Communication
Structure- ‘Grounding’
realization of functionality by aggregating other Web Services - functional
decomposition - WS composition
Non-functional Properties
DC + QoS + Version + financial
- complete item description- quality aspects - Web Service Management
WS
Orchestration
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
WSMO Web Service Description
Web ServiceImplementation(not of interest in Web Service Description)
Choreography --- Service Interfaces ---
Capability
functional description
WS
WS
- Advertising of Web Service- Support for WS Discovery
client-service interaction interface for consuming WS - External Visible
Behavior- Communication
Structure- ‘Grounding’
realization of functionality by aggregating other Web Services - functional
decomposition - WS composition
Non-functional Properties
DC + QoS + Version + financial
- complete item description- quality aspects - Web Service Management
WS
Orchestration
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
WSMO Web Service Description
Web ServiceImplementation(not of interest in Web Service Description)
Choreography --- Service Interfaces ---
Capability
functional description
WS
WS
- Advertising of Web Service- Support for WS Discovery
client-service interaction interface for consuming WS - External Visible
Behavior- Communication
Structure- ‘Grounding’
realization of functionality by aggregating other Web Services - functional
decomposition - WS composition
Non-functional Properties
DC + QoS + Version + financial
- complete item description- quality aspects - Web Service Management
WS
Orchestration
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
WSMO Web Service Description
Web ServiceImplementation(not of interest in Web Service Description)
Choreography --- Service Interfaces ---
Capability
functional description
WS
WS
- Advertising of Web Service- Support for WS Discovery
client-service interaction interface for consuming WS - External Visible
Behavior- Communication
Structure- ‘Grounding’
realization of functionality by aggregating other Web Services - functional
decomposition - WS composition
Non-functional Properties
DC + QoS + Version + financial
- complete item description- quality aspects - Web Service Management
WS
Orchestration
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
VTA
VTA WS ‘Trip Booking’
Capability
provides
Chor.Interf.
Flight Request
Hotel Request
Book Flight
Book Hotel
if hotel = Ø flight.arrivaltime = hotel.arrivaltime
flight information
if flight = Ø
hotel information
process (control + data flow) of goals
Orchestration Definition
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
VTA
VTA WS ‘Trip Booking’
Capability
provides
Chor.Interf.
Flight Request
Hotel Request
Book Flight
Book Hotel
if hotel = Ø
if flight = Ø
process (control + data flow) between “states”+ communication behavior of orchestrating Web Service
Flight WS
Capability
Interface (Chor.)1) get request2) provide offer 3) receive selection4) send confirmation
Orch...
Hotel WS
Capability
Interface (Chor.)1) get request2) provide offer 3) receive selection4) send confirmation
Orch...
flight request
avaiable flights
hotel request
avaiable hotels
book request booking confirmation
book requestbooking confirmation
Runtime Orchestration
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
WSMO Top Level NotionsObjectives that a client wants toachieve by using Web Services
Provide the formally specified terminologyof the information used by all other components
Semantic description of Web Services: - Capability (functional)- Interfaces (usage)
Connectors between components with mediation facilities for handling heterogeneities
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
Mediation• For 1$ on programming, $5 - $9 on integration• Mismatches on structural / semantic /
conceptual / level • Assume (nearly) always necessary • Description of role
© IBM, Nelson Mattos
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
WSMO Mediators Overview
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
Mediator StructureWSMO Mediator
uses a Mediation Service via
Source Component
Source Component
TargetComponent1 .. n
1
Mediation Services
- as a Goal - directly- optionally incl. Mediation
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
Building SWS Applications
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
Generic Application Structure
SWS SWS SWSSWS
SWS SWS SWS SWS
Presentation
IT systems
Organisation 1
IT systems
Organisation 2
DB DB
Web ApplicationWeb Application Web ApplicationWeb Application Web ApplicationWeb Application
Semantic Web Services (WSMX/IRS-III)
WSWS WSWSWSWS WSWS Services Abstraction
LegacySystems
SWS
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
Generic Application Structure
SWS SWS SWSSWS
SWS SWS SWS SWS
Presentation
IT systems
Organisation 1
IT systems
Organisation 2
DB DB
Web ApplicationWeb Application Web ApplicationWeb Application Web ApplicationWeb Application
Semantic Web Services (WSMX/IRS-III)
WSWS WSWSWSWS WSWS Services Abstraction
LegacySystems
SWS
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
Generic Application Structure
SWS SWS SWSSWS
SWS SWS SWS SWS
Presentation
IT systems
Organisation 1
IT systems
Organisation 2
DB DB
Web ApplicationWeb Application Web ApplicationWeb Application Web ApplicationWeb Application
Semantic Web Services (WSMX/IRS-III)
WSWS WSWSWSWS WSWS Services Abstraction
LegacySystems
SWS
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
Generic Application Structure
SWS SWS SWSSWS
SWS SWS SWS SWS
Presentation
IT systems
Organisation 1
IT systems
Organisation 2
DB DB
Web ApplicationWeb Application Web ApplicationWeb Application Web ApplicationWeb Application
Semantic Web Services (WSMX/IRS-III)
WSWS WSWSWSWS WSWS Services Abstraction
LegacySystems
SWS
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
Generic Application Structure
SWS SWS SWSSWS
SWS SWS SWS SWS
Presentation
IT systems
Organisation 1
IT systems
Organisation 2
DB DB
Web ApplicationWeb Application Web ApplicationWeb Application Web ApplicationWeb Application
Semantic Web Services (WSMX/IRS-III)
WSWS WSWSWSWS WSWS Services Abstraction
LegacySystems
SWS
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
Supporting Emergency Planning for
Essex County Council
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
Essex County Council
• A large local authority in South East England
• Comprised of 13 boroughs • Population of 1.3M.
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Emergency Planning Context
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
Emergency planning scenarioPlan emergency
response
WHAT INFORMATION AVAILABLE?
SELECT RELEVANT INFORMATION
Severe weather event
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
Emergency planning scenarioSevere weather event forecast in the area by
Met Office
Met Office
get event details
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
Emergency planning scenario
Identify most appropriate rest centres
ViewEssex spatial data
get centre contact details
District data
get facilitieskitchen, showers, number of beds, cookers, heaters…
get capacity
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
eMerges Ontologies
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
Demonstration of Emergency Planning (GIS) Prototype V1
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EMerges Prototype Architecture
ViewEssexServices
Em
ergency-GIS
-Dom
ainE
mergency-G
IS-D
omain
Em
ergency-GIS
-Goals
Em
ergency-GIS
-Goals
BuddySpaceServer
BuddySpaceServices
BuddySpace GoalsBuddySpace Goals
Smart FilterServices
ArchetypesArchetypes
SGIS-SpatialSGIS-Spatial
Google Web Toolkit
EnvironmentServices
ME
T-Office-D
omain
ME
T-Office-D
omain
ME
T-Office-G
oalsM
ET-O
ffice-Goals
AccommodationGoalEnvironment Goal
Presence Goal
Affordances = Goals
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SAWSDL and WSMO-Lite
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
WSDL
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
WSMO
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
WSMO Service (& Goal)
service
capabilityinterface
orch chor
I/O/P/E
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
WSMO Service (& Goal)
service
capabilityinterface
orch chor
I/O/P/EWSDL
grounding
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
WSMO-Lite in WSDL
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
WSMO + WSDL
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
Types of Service Semantics• Functional
– What the service does
• Nonfunctional– Implementation or running env. information
• Behavioral– How to talk to the service
• Information– What the exchanged data means
(adapted from Amit Sheth)
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
WSMO-Lite Example<wsdl:description>
<wsdl:types> <xs:schema><xs:element name="ReservationRequest"
sawsdl:modelReference="&ex;Reservation"sawsdl:loweringSchemaMapping="&ex;ResMapping.xsparql" … />
</xs:schema> </wsdl:types><wsdl:interface name="HotelReservations"
sawsdl:modelReference="&ex;AccommodationReservationService">
<wsdl:operation name="searchForRooms"sawsdl:modelReference="&wsdlx;SafeInteraction">
…</wsdl:operation>…
</wsdl:interface><wsdl:service name="RomaHotels" interface="HotelReservations"
sawsdl:modelReference="&ex;RomaHotelReservationPrecondition&ex;ReservationFee" … />
</wsdl:description>
II
F
B
FN
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
SAWSDL – Help From W3C
But:no predefined
semantics!
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
WSMO-Lite vs. WSMO
• WSMO-Lite service model from WSDL
• Goals out of scope• Ontologies imported• Mediators out of scope• No new syntaxes, just a few terms
– Using the simplest parts of RDFS• WSMO-Lite is an application of
SAWSDL
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
WSMO-Lite Termswl:Ontology rdf:type rdfs:Class;
rdfs:subClassOf owl:Ontology.wl:ClassificationRoot rdfs:subClassOf rdfs:Class.wl:NonFunctionalParameter rdf:type rdfs:Class.wl:Condition rdfs:subClassOf wl:Axiom.wl:Effect rdfs:subClassOf wl:Axiom.wl:Axiom rdf:type rdfs:Class.
• Allows different types of semantics on a single component
• E.g. functionality and nonfunc. property on a service
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MicroWSMO
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
WS-* Service ModelWSDL service
Operation 1
Operation 2
Operation N
input
input
input
output
output
output
...
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
What are RESTful WS?
• Like Web applications, but for machines• Or like WS-*, but with more resources
• A RESTful Web service is:– A set of Web resources– Interlinked– Data-centric, not functionality-centric– Machine-oriented (no more HTML-scraping)
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
Summary• Semantic Web Services
– Applies SW to automate application development through reuse of Web services
• WSMO– ontology describing Web services– Goals, web services, mediators
• Supporting Emergency Planning • WSMO-Lite• SAWSDL• MicroWSMO
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
Relevant URLs (1/2)• WSMO
– http://www.wsmo.org/• IRS-III
– http://kmi.open.ac.uk/projects/irs/• DIP
– http://dip.semanticweb.org/• Emergency Planning Use Case
– http://irs-test.open.ac.uk/sgis-dev/
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
Relevant URLs (2/2)• Conceptual Models of Services
– http://cms-wg.sti2.org/home/• OWL-S
– http://www.daml.org/services/owl-s/• SAWSDL
– http://www.w3.org/2002/ws/sawsdl/
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)
Thanks
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The Sixth Summer School on Ontological Engineering and the Semantic Web (SSSW'08)