Modeling and manipulating context in pervasive computing based on set theory

Context awareness is one of the key characteristics of ubiquitous and pervasive computing. Most current formalism works focus on two aspects: context representing and system modeling. However, how the temporal property of context can be modeled and how context can be manipulated are not well addressed. This paper proposes a formal way based on set theory for modeling and manipulating context, in which a context is defined as a set of context entries and operators are introduced to specify how to manipulate contexts in according to the needs of different applications. To show the usability of the proposed model, a demo implementation is also included in this paper.