Research On The Technologies Of Processing Continuous K-nearest Neighbor Queries Over Moving Objects

Location based service(LBS) provides users with services related to their positions which can be obtained through mobile devices and wireless networks infrastructure.In dynamic environment,the moving objects database(MOD) manage the positions of moving objects equiped GPS such as vehicles,fleets and airplanes,and provide location-dependent queries. Continuous K-Nearest Neighbor(CKNN) Query is a kind of basic query provided by moving objects database ,is worth to research.After more than ten years' research, key technologies of MOD have been extensively studied and rich achievements have been got.The advancement of technologies bring more applications. However, MOD as a systematical application lacks of the support to concurrent query processing,especially,for some special environment.There are urge requirements on studying more to support concurrent query processing.To evaluate multiple continuous k nearest neighbor queries,through in-depth study on classical technologies,combined application background, This dissertation propose two algorithms,one on highly dynamic moving environment and the other base on a novel distributed computing framework.The main work and innovations are detailed as follows:(1) In highly dynamic environment,we propose an algorithm for processing Multiple Continuous K-Nearest Neighbor Queries based on query index, discuss the solution to construct the grid index and evaluate the queries,and experimental results verify the effectivity .(2) Since actual query clients could implement complex computing, we propose a novel distributed computing framework of CKNN Query,which shares the burthen of server,and promotes the efficiency to process queries.The experimental results verify that this algorithm performs better than the algorithms centralized in server.(3) Based on a high-speed moving object generater, we design and implemente a experimental system that supports multi-queries.The experimental system not only provides experiment platform,but also provides a platform to display, validate algorithms and test the performance.And,as basic LBS,the system establishs a foundation for promoting practicality of related work.