The document introduces ontology and describes what it is from both philosophical and computer science perspectives. An ontology in computers consists of a vocabulary to describe a domain, specifications of the meaning of terms, and constraints capturing additional knowledge about the domain. It then provides an example ontology and discusses applications of ontologies such as for the semantic web. It also discusses important considerations for building ontologies such as collaboration, versioning, and ease of use.

1. Introduction to Ontology Sudarsun S Director – Research Checktronix India Chennai 600010

5. Example Ontology ( Protégé )

6. What ?? Catalog/ID General Logical constraints Terms/glossary Thesauri “ narrower term” relation Formal is-a Frames (properties) Informal is-a Formal instance Value Restrictions Disjointness, Inverse, part-of

29. Mapping, Merging, Alignment car vehicle car vehicle vehicle car

31. SMART Algorithm Setup: load files, set preferences, ... Execute operation: perform automatic updates, detect conflicts, create suggestions Select operation: choose from suggestion list, create a new operation, …. Initial suggestions: identical names, synonyms, superclasses for top-level classes in alignment

35. Source – Car Rental

36. Source – Airline Reservation

40. RDF Syntax -- Triples _:xxx _:yyy « plain littéral » « lexical »^^data type Subject Property Object ex: Subject ex: Property ex: Object

41. RDF Syntax -- Graph _:xxx « Palani Ramasamy » ex:name ex:Person rdf:type « University of Madras » ex:Organisation ex:name rdf:type _:yyy ex:member-of

48. DL System Architecture Knowledge Base Tbox (schema) Abox (data) Inference System Interface Man ´ Human u Male Happy-Father ´ Man u 9 has-child Female u … Jagan : Happy-Father < Jagan, Mythili> : has-child Jagan: 6 1 has-child