Time ontology with Reference Event based Temporal Relations (RETR)

Ontology of time is gaining importance as it is necessary to realize the Semantic Web. They play animportant role in Natural Language Processing applications, data mining, decision support systems etc.Existing time ontologies have been represented using DAML, OWL, KSL, KIF and Cyc. In time ontology,events are concepts and topological temporal relations between events are either Point based or Intervalbased. Allen has proposed temporal interval relations which have been represented in the existing timeontologies. Among the Allen’s 13 temporal relations the ‘before’ relation is ambiguous as it is contextdependent. In this work, the ‘before’ relation has been augmented with 3 more specific relative event basedtemporal relations which increases the efficiency of temporal reasoning. A temporal ontology when createdfor medical domain using Protégé OWL can be an efficient decision support system when the additionaltemporal relations RETR are incorporated.