Time ontology with Reference Event based Temporal Relations (RETR)

Abstract

Ontology of time is gaining importance as it is necessary to realize the Semantic Web. They play an important 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 Interval based. Allen has proposed temporal interval relations which have been represented in the existing time ontologies. Among the Allen’s 13 temporal relations the ‘before’ relation is ambiguous as it is context dependent. In this work, the ‘before’ relation has been augmented with 3 more specific relative event based temporal relations which increases the efficiency of temporal reasoning. A temporal ontology when created for medical domain using Protege OWL can be an efficient decision support system when the additional temporal relations RETR are incorporated.