Luciano Serafini IRST Towards a Distributed Reasoning within Multiple Ontologies 2K* symposium September 6-9, 2004 Madonna di Campiglio Andrei Tamilin UniTN & by

2K* : Towards a Distributed Reasoning - p.2 Talk Outline Preamble: Ambitions and Realities of SW. Motivation: Why and how to distribute? Formal framework: DDL in a nutshell Reasoning in DDL DRAGO – reason-able implementation

2K* : Towards a Distributed Reasoning - p.3 Preamble: The distant 2001 … The Semantic Web. By Tim Berners-Lee, James Hendler and Ora Lassila. A new form of Web content that is meaningful to computers will unleash a revolution of new possibilities. Original driver: Automation Means: “Machine-friendly” web metadata Means: “Machine-friendly” web metadata Goal: Application interoperability Means: Ontology Means: Ontology

2K* : Towards a Distributed Reasoning - p.4 Preamble: Three years later … SW equipment: Languages: RDF, RDFS, DAML, OIL, DAML- OIL, OWL Languages: RDF, RDFS, DAML, OIL, DAML- OIL, OWL Theory: Description Logics (DL) Theory: Description Logics (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: , KnowledgeWeb project , KnowledgeWeb project

2K* : Towards a Distributed Reasoning - p.5 Preamble: The realities Ontology proliferation: Galaxy of ontologies Galaxy of ontologies Galaxy distinguishing features: features: Multiplicity Multiplicity Heterogeneity Heterogeneity Making ontologies interoperate: Means: Semantic mappings Means: Semantic mappings Enough? Enough? No No Reasoning support is required! Reasoning support is required!

2K* : Towards a Distributed Reasoning - p.6 Preamble: The realities Cosmopolitism of current reasoning methodology: reasoning methodology: Global ontology Global ontology Reason in global Reason in globalontology Arising questions: Scalability? Scalability? Reasoning specificity? Reasoning specificity? Privacy? Autonomy? Privacy? Autonomy?

2K* : Towards a Distributed Reasoning - p.7 Alternative approach: Local reasoning Local reasoning Suitable combination Suitable combinationRequirements: Formal framework Formal framework Reasoning algorithm Reasoning algorithm The reason-able The reason-able system implementation Motivation: Towards a distribution

2K* : Towards a Distributed Reasoning - p.8 Formal framework: DDL in a nutshell Distributed Description Logics (DDL) Captures the case of multiple ontologies pairwise linked by semantic mappings Captures the case of multiple ontologies pairwise linked by semantic mappings Ontologies: DL knowledge bases DL knowledge bases (T-box and A-box) (T-box and A-box) Mappings: Bridge rules Bridge rules (M-box) (M-box) T-box A-box T-box A-box T-box A-box T-box A-box M-box

2K* : Towards a Distributed Reasoning - p.9 Reasoning in DDL Similarly to DL: Core reasoning task in DDL – concept subsumption Core reasoning task in DDL – concept subsumption Difference from DL: Scope – Galaxy Scope – Galaxy Mappings matter Mappings matter Subsumption in DDL – a global subsumption C D Earth B A C D GalaxyNeptune: A B

2K* : Towards a Distributed Reasoning - p.10 Distributed reasoning algorithm Local Tableau Propagation Local Tableau Propagation Local Tableau Propagation Local Tableau Propagation Cycle is detected Reasoning is finished

2K* : Towards a Distributed Reasoning - p.11 DRAGO Manager 3 DRAGO Distributed Reasoning Architecture for Galaxy of Ontologies DRAGO Manager 1 DRAGO Manager 2

2K* : Towards a Distributed Reasoning - p.12 Grazie Dziaku j

2K* : Towards a Distributed Reasoning - p.13 Questions?

2K* : Towards a Distributed Reasoning - p.14 Acknowledgements We thank Kevin Palivec for the beautiful picture of DRAGO 1 he painted. We promise that it will be used by us for the research purposes only. 1