Abstract
Sensor networks have received considerable attention in recent years, and are often employed in the applications where data are difficult or expensive to collect. One of the features for wireless sensor networks is resource limitations. Sensor nodes typically are limited in computing power, network bandwidth, storage capability, and energy supply. Resource conservation therefore becomes a major consideration when devising sensor applications. With the continuous development of sensor network technology, we can imagine that in the near future the sensor network must be of a large scale and the service oriented applications. In such environment, hundreds of queries can be presented. Multi-query optimizations become important for efficient query processing. The previous multi-query optimization works only consider multiple aggregate queries with different predicates. In this thesis, we present techniques to extend the previous multi-query optimization strategies by further considering different query regions. We process the queries by considering the spatial relationship of all query regions. Strategies for exploiting the properties of overlapped regions to obtain a better solution are developed. Moreover, extensive experiments are made to demonstrate the efficiency of the proposed optimization techniques.