adfa, p. 1, 2011. © Springer-Verlag Berlin Heidelberg 2011 A Model of Derived Roles Kouji KOZAKI, Yoshinobu KITAMURA and Riichiro MIZOGUCHI The Institute of Scientific and Industrial Research, Osaka University 8-1 Mihogaoka, Ibaraki, Osaka, 567-0047 Japan {kozaki, kita, miz}@ei.sanken.osaka-u.ac.jp Abstract. Roles are important concepts in order to consider practical instance managements. Although roles have been discussed by many researchers, there remains some room to investigate to clarify ontological characteristics of them. This paper focuses on roles which are dependent on the future or past event/process, such as candidate, departing passenger, murderer, and product etc. In order to deal with such kinds of roles based on an ontological theory of roles, we introduce a model of derived roles with its temporal model. It could provide a computational model to represent temporal characteristics of roles. Keywords: ontological engineering, role, derived roles, temporal model 1 Introduction It is very important for ontology building to distinguish clearly among concepts in the real world based on their characteristics. Dependences of things are one of key char- acteristics which we should pay attention when we develop ontologies. So, how to deal with “dependency” is one of the key technologies in ontology building. Among them roles such as customer, president, pedestrians, etc. are dependent on other enti- ties. A company can be a customer of another company while being a supplier to others. Proper treatment of roles is crucial to building a good ontology. This is why the topic of roles has been investigated extensively in several areas of ontology engi- neering[1-6], biomedical[7], database model[8], software engineering[9], and agent systems[10] etc. In practical point of view, in order to consider identity of some enti- ties for instance management, it is important to understand characteristics of roles[11]. Although roles have been discussed by many researchers, there remains some room to investigate to clarify ontological characteristics of them. For examples, is murderer a role? Some answer no. A reason would be because one cannot stop being a murderer once he/she has started to play it. Another would be “it is odd to say “he plays a murderer” if not in a drama”. Although these reasons are reasonable to some extent, we need a convincing explanation of what murderer is ontologically. This paper focuses on roles which are dependent on the future or past event/process, such as candidate, departing passenger, murderer, and product etc. In order to deal with such kinds of roles based on an ontological theory of roles, we introduce a model of derived roles with its temporal model. This paper is organized as follows. The next section overviews our model of roles discussed in [3] to provide readers with background of the discussion of a new model