Edinburgh

1
Oscar Corcho, Pinar Alper, Ioannis Kotsiopoulos,
Paolo Missier, Sean Bechhofer, Carole
Goble University of Manchester
Edinburgh 07/06/06
2
Outline

• OntoGrid and S-OGSA
• The S-OGSA model
• S-OGSA capabilities and mechanisms
• OntoKit as a S-OGSA realisation
• S-OGSA scenarios of use
• Current (and Future) Requirements for RDF triples
• Conclusions and Future Work

3
EU-STREP Project OntoGrid

• SEMANTIC OGSA
• Capabilites Behaviors for Semantic Grids
• Principled way of realization

• Middleware for the Semantic Grid
• P2P - Distributed, Scalable, Reliable Metadata
  Storage Querying (Atlas).
• Ontology Access WS-DAIOnt-RDFS
• Annotation
• Data and provenance
• Knowledge Parser
• Services
• ODE-SGS
• Intelligent Debugging
• Agents Negotiation and Coordination

• Applications
• Insurance Settlement
• Satellite Image Quality Analysis

4
S-OGSA Desiderata

• Parsimony Architecture as lightweight as
  possible minimise the impact on tooling, not
  dictate content
• Extensibility Extensible and customisable as
  opposed to complete and generic architecture
• Diversity Mixed ecosystem of Grid and Semantic
  Grid services. Semantics Ignorant, Semantics
  aware but incapable, Semantics aware and capable
• Enlightenment Straightforward migration path
• Uniformity Everything is OGSA compliant. Our
  services are Grid services, knowledge and
  Metadata are Grid Resources.
• Multiform-Multiplicity Any resource can have
  multiple descriptions and any description can be
  in different formalisms
• Conceptual reference architecture that can be
  applied to any grounding (WSRF, WS-Man, WS-I,
  etc.)

5
S-OGSA

• Semantic-OGSA (S-OGSA) is...
• Our proposed Semantic Grid reference architecture
• A low-impact extension of OGSA
• Mixed ecosystem of Grid and Semantic Grid
  services
• Services ignorant of semantics
• Services aware of semantics but unable to process
  them
• Services aware of semantics and able to process
  (part of) them
• Everything is OGSA compliant
• Defined by
• Information model
• New entities
• Capabilites
• New functionalities
• Mechanisms
• How it is delivered

Model
provide/ consume
expose
Capabilities
Mechanisms
use
6
S-OGSA Model
7
S-OGSA Model
8
S-OGSA Capabilities From OGSA to S-OGSA
Application 1
Application N
Optimization
Security
Data
OGSA
Execution Management
Semantic-OGSA
Semantic Services
Resource management
Information Management
Infrastructure Services
9
S-OGSA Capabilities From OGSA to S-OGSA
Application 1
Application N
Optimization
Security
Data
OGSA
Execution Management
Semantic-OGSA
Semantic Services
Resource management
Information Management
Infrastructure Services
10
S-OGSA Mechanisms
Query/Retrieval Result
Metadata Service
Ontology Service
Metadata Service
Ontology Service
Metadata Retrieval/Query Request
Obtain schema for Semantic Bindings
Client
Lifetime
Semantic Binding IdsRetrieval Request
Notification
Resource
State/properties metadata
Semantic Binding Ids
. . .
Service

• WSRF defined operations
• getProperties
• queryProperties

11
OntoKit Refactored and additional components
Coordinationandnegotiation
Coordinationandnegotiation
Semantically Aware
IntelligentDebugging
IntelligentDebugging
12
Outline

• OntoGrid and S-OGSA
• The S-OGSA model
• S-OGSA capabilities and mechanisms
• OntoKit as a S-OGSA realisation
• S-OGSA scenarios of use
• Current (and Future) Requirements for RDF triples
• Conclusions and Future Work

13
S-OGSA Scenario. Authorisation
CarFraudService (PEP)
getInsurancePolicy
1
PIP Proxy
PDP Proxy
Result or Exception
8
XACML AuthZ Request
XACML AuthZ Response
3
7
Lookup whether the ROLE that is inferred permits
or not
XACML_AuthZService(PDP)
6
2
Obtain Semantic Bindings of John Doe
Atlas
Obtain all classes that are subclass of ROLE
RDF
4
Classify John Doe wrt VO ont
5
John Doe has had 2 distinct accidents
WS-DAIOnt
VO Ontology Class Hierarchy -RDFS
Pellet Reasoner
Ignorant of semantics
VO OntologyOWL
Semantic aware but incapable of processing
semantics
Semantic aware and capable of processing semantics
Semantic provisioning services
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S-OGSA Scenario. Satellite Image Quality Analysis
Satellite Routine Operations

• Scenes
• Routine operations
• Metadata generation
• Report retrieving

• Satellite LifeCycle
• Launch and Early Orbit Phase ( 3 days)
• Calibration and Validation campaign ( 6-9
  months)
• Routine operations ( 5-9 years)
• Satellite de-orbiting. Product processing
  continues

15
S-OGSA Scenario. Satellite Image Quality Analysis
XML Summary File
2
WebDAV client e.g. MS Windows Explorer
WebDAV
HTTP PUT
3
Annotate file
1
Copy satellite XML summary file
4

UTC2Seconds Soaplab
Grid-KP
Obtain ontology
Convert time to canonical representation
6
Type metadata
Convert time to canonical representation
Store
7
Input criteria
1
2
QUARC-SG client JSP
3

WS-DAIOnt
Metadata Service
Query
Atlas
RDF
RDF
SatelliteDomain Ontology
Metadata generation process
Metadata querying process
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S-OGSA Scenario. Insurance settlement

• Data and resources scenarios
• Register Repair Co. contract at CarRepairGrid.
• Select Repair Companies for negotiation
• Metadata scenarios
• Calculate offer by a Repair Company (damage
  report)
• Judge Invoice sent by Repair Company
• Process management scenarios
• Multi issue negotiation between Repair Companies
  (repair)
• Multi issue negotiation between gt3 insurance
  companies (Recovery)
• Services scenarios
• Provide Policy Information
• Check coverage
• Security scenarios
• Check client registration at insurance companies
• Check Car Theft - automatic check on car identity
  i.e. frame numbers and parts

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S-OGSA Scenario. Insurance settlement
Negotiation client
Job
2
Cfp
Refuse
4
1
Do Negotiation
calculatePrice
3
Job Contractor List
accept
5
Job
Cfp

2
Retrieve public Job desc.
Negotitation Service (Manager)
propose
Offer
4
calculatePrice
3
Reject
5
Job
Cfp
2

WS-DAIOnt
RDF
RDF
Offer
RDF
propose
calculatePrice
4
3
InsurranceCo DB
WS-DAIOnt

Atlas

RDF
RDF
RDF
RDF
RDF
Legacydatabases
Car Parts
Legacydatabases
Motor Vahicles
Car Repair DB
Car Repair DB
18
Outline

• OntoGrid and S-OGSA
• The S-OGSA model
• S-OGSA capabilities and mechanisms
• OntoKit as a S-OGSA realisation
• S-OGSA scenarios of use
• Current (and Future) Requirements for RDF triples
• Conclusions and Future Work

19
Current requirements

• Basic...
• Storage of RDF triples
• Query functions SELECT and CONSTRUCT
• Basic RDFS inferences
• More advanced...
• Named graphs / Contexts / Reification
• Semantic Bindings are named after the Grid and
  Knowledge Entities they refer to
• Query functions over a set of Semantic Bindings
• Be able to distinguish whether we want to query
  the whole repository, without named graph
  distinctions, or only over specific Semantic
  Bindings.
• We need easier ways to specify where the query is
  to be executed
• RDF triple location transparency
• We only know the URIs of the resources
• We need RDF triple stores that can handle
  distributed RDF data sources

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Future requirements. Lifetime (I)

• Relationship with the lifetime of entities that a
  SB refers to
• What happens if any of the Grid entities
  disappears?
• Instrument and planning files for satellites do
  not disappear
• Insurance contracts, cars, repair companies,
  etc., may disappear
• What happens if all the Grid entities disappear?
• Relationship between a damage report and a car
  repair company
• What happens if the Knowledge entities disappear
  or evolve?
• Ontologies may change
• How often should this be checked?
• We need
• Built-in notification mechanisms
• Built-in configurable behaviours for Grid and
  Knowledge Entity evolution

21
Future requirements. Lifetime (II)

• SB own lifetime
• What happens if a SB is no longer available?
• Technical problems How can this happen? Metadata
  service not available? Replication needed?
• Content problems Existing SB content does not
  make sense.
• Damage claims add witness reports, improve info
  about accident location...
• What should be the behaviour of
  Semantically-Aware Grid Services when they
  receive such an error? How should we fix dangling
  links?
• When do/should SBs become invalid? Should we
  specify SB lifetime in the moment of creation?
• SBs associated to a contract between an insurance
  company and a repair company have a lifetime of X
  months.
• What is the status of the content of a SB?
• Content checked, stable, unchecked, etc.
• SBs associated with an instrument can have
  different states
• We need
• Built-in notification mechanisms
• Built-in configurable behaviours/properties about
  SB lifetime
• SB Graveyards

22
Future requirements. Naming

• What are appropriate naming schemes for SBs?
• Random name
• LSIDs
• URIs
• How to find semantic bindings?
• By Grid Entity references
• By Knowledge Entitiy references. Granularity of
  Knowledge Entity?
• Concepts and properties
• Complete ontologies
• By content of the SB
• We need
• Built-in configurable naming schemes to be used
  depending on the applications
• Fast query mechanisms (indices) to find SBs
• Service and Resource discovery functions

23
Future requirements. Authorisation

• Access control (AuthZ)
• Which SBs can/should I be able to
  retrieve/contribute?
• Granularity graph name / context,
  conceptsproperties
• AuthZ over entities that do not exist yet.
  Factory patterns?
• How to enforce AuthZ wrt RDF queries on a
  repository?
• Granularity graph name, contexts,
  conceptsproperties
• We need
• Built-in AuthZ mechanisms over SBs and Knowledge
  Entities
• Declarative
• Exploiting RDFS semantics to specify patterns
• Introspection over RDF queries to specify AuthZ
  with more granularity

24
Future requirements. Dealing with legacy data

• Access to legacy data using RDF query languages
• Examples
• Car repair company databases
• Insurance company databases
• Contracts
• Annotation (creation of Semantic Bindings)
• Annotation services (from free text, HTML,
  XML...)
• R2O (from relational databases)
• We need
• Built-in support for relational-to-RDF
  transformations (run-time query rewriting)

25
Outline

• OntoGrid and S-OGSA
• The S-OGSA model
• S-OGSA capabilities and mechanisms
• OntoKit as a S-OGSA realisation
• S-OGSA scenarios of use
• Current (and Future) Requirements for RDF triples
• Conclusions and Future Work

26
Conclusions and future work

• Requirements based on
• S-OGSA model characteristics
• OntoGrid use cases
• We are interested in obtaining feedback from
  other use cases/projects
• What do you need?
• Future work (S-OGSA v2. September 2006)
• Patterns of interaction
• Common patterns used in the Semantic Grid
  (annotation of dynamic sources, exploitation of
  Semantic Bindings, etc.)
• S-OGSA Profiles
• Configurations of S-OGSA depending on types of
  applications
• How are ontologies used (data structures,
  reasoning structures, etc.)lt

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Access to S-OGSA

• Publications
• An overview of S-OGSA a Reference Semantic Grid
  Architecture. Corcho O, Alper P, Kotsiopoulos I,
  Missier P, Bechhofer S, Goble C. Journal of Web
  Semantics. In press
• Source code
• http//www.ontogrid.net/, For Downloading
  Distributions
• Access to CVS
• Connection type pserver
• user ontogrid
• password not needed
• Host rpc262.cs.man.ac.uk
• Port 2401
• Repository path /local/ontogrid/cvsroot
• module prototype

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Questions

• Thank you for your attention!
• Questions?
• Acknowledgements
• OntoGrid Consortium

29
Oscar Corcho, Pinar Alper, Ioannis Kotsiopoulos,
Paolo Missier, Sean Bechhofer, Carole
Goble University of Manchester
Edinburgh 07/06/06