Luciano SerafiniLuciano SerafiniIRSTIRST

Towards a Distributed ReasoningTowards a Distributed Reasoningwithin Multiple Ontologieswithin Multiple Ontologies

2K* symposium2K* symposium

September 6-9, 2004September 6-9, 2004 Madonna di CampiglioMadonna di Campiglio

Andrei TamilinAndrei TamilinUniTNUniTN &

byby

2K* - 2004: Towards a Distributed Reasoning2K* - 2004: Towards a Distributed Reasoning - p. - p.22

Talk OutlineTalk Outline

Preamble: Ambitions and Realities of SW.Preamble: Ambitions and Realities of SW.

Motivation: Why and how to distribute?Motivation: Why and how to distribute?

Formal framework: DDL in a nutshellFormal framework: DDL in a nutshell

Reasoning in DDLReasoning in DDL

DRAGO – reason-able implementationDRAGO – reason-able implementation

2K* - 2004: Towards a Distributed Reasoning2K* - 2004: Towards a Distributed Reasoning - p. - p.33

Preamble: The distant 2001 …Preamble: The distant 2001 …

The Semantic WebThe Semantic Web. . By Tim Berners-Lee, By Tim Berners-Lee, James Hendler and Ora LassilaJames Hendler and Ora Lassila..

A new form of Web content that is meaningful to A new form of Web content that is meaningful to computers will unleash a revolution of new computers will unleash a revolution of new possibilitiespossibilities..

Original driver: AutomationOriginal driver: Automation Means: “Machine-friendly” web metadataMeans: “Machine-friendly” web metadata

Goal: Application interoperabilityGoal: Application interoperability Means: OntologyMeans: Ontology

2K* - 2004: Towards a Distributed Reasoning2K* - 2004: Towards a Distributed Reasoning - p. - p.44

Preamble: Three years later …Preamble: Three years later …

SW equipment:SW equipment: Languages: RDF, RDFS, DAML, OIL, DAML-Languages: RDF, RDFS, DAML, OIL, DAML-

OIL, OWLOIL, OWL Theory: Theory: DDescription escription LLogics (DL)ogics (DL) Reasoning support: FaCT, Racer, Pellet, etc.Reasoning support: FaCT, Racer, Pellet, etc. Management: plenty of tools …Management: plenty of tools …

It’s time to make the SW a reality:It’s time to make the SW a reality: 2004-2006, 2004-2006, KnowledgeWeb KnowledgeWeb projectproject

2K* - 2004: Towards a Distributed Reasoning2K* - 2004: Towards a Distributed Reasoning - p. - p.55

Preamble: The realitiesPreamble: The realitiesOntology proliferation:Ontology proliferation: Galaxy of ontologiesGalaxy of ontologies

Galaxy distinguishingGalaxy distinguishing

features:features: MultiplicityMultiplicity HeterogeneityHeterogeneity

Making ontologies interoperate:Making ontologies interoperate: Means: Semantic mappingsMeans: Semantic mappings Enough?Enough? NoNo Reasoning support is required!Reasoning support is required!

2K* - 2004: Towards a Distributed Reasoning2K* - 2004: Towards a Distributed Reasoning - p. - p.66

Preamble: The realitiesPreamble: The realities

Cosmopolitism of current Cosmopolitism of current

reasoning methodology:reasoning methodology: Global ontologyGlobal ontology Reason in global Reason in global

ontologyontology

Arising questions:Arising questions: Scalability? Scalability? Reasoning specificity?Reasoning specificity? Privacy? Autonomy?Privacy? Autonomy?

2K* - 2004: Towards a Distributed Reasoning2K* - 2004: Towards a Distributed Reasoning - p. - p.77

Alternative approach:Alternative approach: Local reasoningLocal reasoning Suitable combinationSuitable combination

Requirements:Requirements: Formal frameworkFormal framework Reasoning algorithmReasoning algorithm The reason-able The reason-able

system implementationsystem implementation

Motivation: Towards a distributionMotivation: Towards a distribution

2K* - 2004: Towards a Distributed Reasoning2K* - 2004: Towards a Distributed Reasoning - p. - p.88

Formal framework: DDL in a nutshellFormal framework: DDL in a nutshell

DDistributed istributed DDescription escription LLogics (DDL)ogics (DDL) Captures the case of multiple ontologies Captures the case of multiple ontologies

pairwise linked by semantic mappingspairwise linked by semantic mappings

Ontologies:Ontologies: DL knowledge basesDL knowledge bases

(T-box and A-box)(T-box and A-box)

Mappings:Mappings: Bridge rulesBridge rules

(M-box)(M-box)

T-box A-box

T-boxA-box

T-boxA-box

T-boxA-box

M-box

M-boxM-box

M-box

2K* - 2004: Towards a Distributed Reasoning2K* - 2004: Towards a Distributed Reasoning - p. - p.99

Reasoning in DDLReasoning in DDL

Similarly to DL:Similarly to DL: Core reasoning task in DDL –Core reasoning task in DDL –

concept subsumptionconcept subsumption

Difference from DL:Difference from DL: Scope – Galaxy Scope – Galaxy Mappings matterMappings matter

Subsumption in DDL – Subsumption in DDL –

a global subsumptiona global subsumption

CDEarth

BA

CD

Galaxy Neptune: AB

2K* - 2004: Towards a Distributed Reasoning2K* - 2004: Towards a Distributed Reasoning - p. - p.1010

Distributed reasoning algorithmDistributed reasoning algorithm

Local Tableau

Propagation

Propagation

Local Tableau

Local Tableau

Propagation

Local Tableau

PropagationLocal

Tableau

PropagationCycle is detected

Reasoning is finished

2K* - 2004: Towards a Distributed Reasoning2K* - 2004: Towards a Distributed Reasoning - p. - p.1111DRAGO Manager 3

DRAGODRAGODDistributed istributed RReasoning easoning AArchitecture for rchitecture for GGalaxy of alaxy of OOntologiesntologies

DRAGO Manager 1DRAGO Manager 2

2K* - 2004: Towards a Distributed Reasoning2K* - 2004: Towards a Distributed Reasoning - p. - p.1212

Grazie

Dziakuj

<owl:Class rdf:ID="Polite_Drago"> <rdfs:subClassOf> <owl:Restriction> <owl:onProperty> <owl:ObjectProperty rdf:ID=“tells_after_presentation"/> </owl:onProperty> <owl:someValuesFrom> <owl:Class> <owl:unionOf rdf:parseType="Collection"> <owl:Class rdf:about=“&Luciano;#Grazie"/> <owl:Class rdf:about=“&Andrei;#Dziakuj"/> </owl:unionOf> </owl:Class> </owl:someValuesFrom> </owl:Restriction>

2K* - 2004: Towards a Distributed Reasoning2K* - 2004: Towards a Distributed Reasoning - p. - p.1313

Questions?Questions?

2K* - 2004: Towards a Distributed Reasoning2K* - 2004: Towards a Distributed Reasoning - p. - p.1414

AcknowledgementsAcknowledgements

We thank We thank Kevin Palivec Kevin Palivec for the beautiful for the beautiful picture of DRAGOpicture of DRAGO11 he painted. We promise he painted. We promise that it will be used by us for the research that it will be used by us for the research purposes only.purposes only.

1 http://lair2000.net/Dragon_Pictures/Dragon_Pictures.html