Reliability Logic Model for Incomplete Information in Sensor Monitoring Databases

Ubiquitous network consists of a large number of sensor nodes that combine physical sensing capabilities with networking capabilities. The sensors send data to a central monitoring database server where the data is aggregated. The objective of this research is to reduce the uncertainty of user query for incomplete information in the sensor databases. Typical method to give more informative answers to users is interpolation method. And there has been few researches in the area of handling uncertainty for incomplete information without user-defined probability. But uncertainty handling mechanism with user-defined probability approaches is not desirable to let users catch the meanings of the stored data and the users are not familiar to difficult and complex probability functions. In this paper, a new approach of handling uncertainty, Reliability Logic(RL) model, is proposed, which provides users generality and naturalness of query expression for incomplete monitoring databases. In our RL model, two basic reliability operators are introduced into restriction clause. The extension to RL model can give the users expressive power of monitoring query, notify the degree of uncertainty and reduce the uncertainty of the user query.