Ubiquitous Computing-Oriented Distributed Fuzzy Reasoning Petri Net Modeling and Simulation

In a ubiquitous computing environment, contexts are initially got and stored on those nodes scattered over the environment. However, the traditional reasoning about contexts applied a centralized approach which aggravated the load of reasoning server and cost for communication of context. As an important approach for context reasoning, the rule-based reasoning can be easily decomposed of independent propositions. Therefore, the rule-based context reasoning can be decomposed and distributed over those nodes of the ubiquitous environment to decrease the computing load of reasoning server. In this paper, we propose a distributed fuzzy reasoning Petri net model (dFRPN) towards the decomposition of distributed fuzzy reasoning. dFRPN model is able to formalize the distribution of fuzzy reasoning over every node of the whole environment. dFRPN model is characterized as a hierarchical structure to make a description of reasoning on nodes more clear. Considering the limited capabilities of some mobile nodes such as PDA and smart phone, we add the special migrating transition to define the load detection and corresponding actions. At the end of the paper, the feasibility of dFRPN model is validated through a case of context-awareness based personalized recommendation system.