Learn More
The emergence of Web services has led to more interest into Web service composition, which is an active area of research. The formidable problem of efficient and effective composition of existing Web services is the subject of much current attention. The study of workflow model is one of the most important parts and a key layer of Web service composition.(More)
We present a distributed spatial index called CANQTree based on a content-addressable network (CAN) and QuadTree-alike structures. In our system, both spatial objects and their corresponding nodes in a QuadTree are identified by some points and mapped into CAN zones of peers. For a given spatial range query, CAN-QTree can provide O(n<sup>1/2</sup>) search(More)
With more and more applications of spatial data, agreat demand on business rules related to spatial informationemerges. Active rule integrated into spatial database can beused to implement not only integrity constraint but alsovarious business rules. Condition matching for active rule iscritical to the efficiency of rules execution. However the activerule(More)
Based on decode-and-forward strategy, we investigate the achievable outage probability of opportunistic relaying, in which there is a single source-destination transmission pair with the help of one of multiple relays. In two-hop scenario, based on adaptive decode-and forward strategy, the achievable diversity-multiplexing tradeoff with the knowledge of(More)