Integrating facts and beliefs to model and reason about context

Abstract

This paper presents a twofold context modelling approach that integrates beliefs (uncertain knowledge) and facts to reason about various everyday situations. Awareness of everyday situations enables mobile devices to adapt to the social and conceptual settings in which they operate; it also enables resources which share a similar context to cooperate in order to carry out a distributed task on behalf of their user. Our context modelling process involves the identification of the context of interest, the determination of those aspects of a context which can be captured by employing sensors, the determination of contextual states for each aspect, and finally, the determination of logical and probabilistic relationships between the contextual aspects and the context they represent. We demonstrate our approach by modelling physical places. Data from various heterogeneous sensors build our system's belief, while containment relationships build its factual knowledge regarding places. The system utilises its belief and factual knowledge to reason about the whereabouts of a mobile user. © IFIP International Federation for Information Processing 2007.