Research On Detection Approah Of Non-deterministic RFID Composite Event

In recent years, with the development of micro-electronics, computer and network technologies, RFID technology has been applied widely. With the expasion of RFID technology, people realize that the original data(ie.primitive event) except for item identification and tracking, the combination(ie.composite event) often contains the meaning of certain application, can support higher level business applications. This implies that the ability of RFID data, causing great concern to academia and industry. How to efficiently detect and found that the composite event to support the business areas of complex applications become a new hotspot.In this paper, according to our event detecting research on RFID data stream, we propose a new detecting approach based pool partitions named dpool, specific working is as follows:This method for resolve useless detecting useless load and sequence of events occur problems, suggested gradually moved the events filters rule; Aiming at coping with more complex queries and filters interference problems, propose inquiries pool and pool partition principle; Aiming at coping with the problem of time distance of events, set the dynamic time pool, gave the pollicy of time pool. The data structures and matching of RFID is simple, detecing the common composite event have a good performance.When the composite event is more complex, dpool method requires multiple trigger query pool area to check whether the composite event expression is true, to spend more time.In this paper, in order to make up dpool method, propose a composite event detecting method based extend-dpool. Specific tasks are as follows:given tree-based conversiton pool, transform the composite event into event tree,propose the principle of transform and the extended tree of each operator, in the process of composite events into the event tree also allocate the time pools, given the policy.In the end, The e-dpool and dpool mehords have been verified the rationality and effectiveness by experimrnts, dpool more suitable for commmon composite event detection. However, e-dpool method has more performance on deal with more composite events.