A General Methodology for Equipping Ontologies with Time
Hans‐Ulrich Krieger · 2010
In the first part of this paper, we present a framework for enriching arbitrary upper or domain-specific ontologies with a concept of time.To do so, we need the notion of a time slice.Contrary to other approaches, we directly interpret the original entities as time slices in order to (i) avoid a duplication of the original ontology and (ii) to prevent a knowledge engineer from ontology rewriting.The diachronic representation of time is complemented by a sophisticated time ontology that supports underspecification and an arbitrarily fine granularity of time.As a showcase, we describe how the time ontology has been interfaced with the PROTON upper ontology.The second part investigates a temporal extension of RDF that replaces the usual triple notation by a more general tuple representation.In this setting, Hayes/ter Horst-like entailment rules are replaced by their temporal counterparts.Our motivation to move towards this direction is twofold: firstly, extending binary relation instances with time leads to a massive proliferation of useless objects (independently of the encoding); secondly, reasoning and querying with such extended relations is extremely complex, expensive, and error-prone.* The research described here has been financed by the European Integrated projects MUSING (Multi-Industry Semantic-Based Business Intelligence, http://musing.eu/) and CogX (Cognitive Systems that Self-Understand and Self-Extend, http://cogx.eu)under contract numbers FP6-027097 and FP7 ICT-215181.I would like to thank the three referees for their valuable comments.