Optimal Path Quries And Application In Road-Networks

Spatial query becomes the key technology of current research field in spatial database, the position queries was widely used to practical applications with the developing of spatial database,such as geographic information systems, urban planning and resource alposition and other fields, and has become a hot research topic. In real life, the position queries which based on the actual road network distance are more in line with actual needs of people, this paper focuses on the optimal position query in the road network, the detail as follows:First, the optimal position query techniques were studied in Euclidean space, but query processing algorithms which based on the European space can not be directly applicable to road network , In addition, the computational cost of query is too high through calling algorithms of nearest neighbor queries in road network repeatly,so the optimal position query in the road network has not been solved. The optimal position query in road networks is partitioned into two-stage of filtration and purification through analysising and discussing the nearest neighbor query in road networks. And the algorithm of optimal loaction query in the road networks is proposed, further the correctness of the algorithm is discussed, additional the algorithm is analyzed and illustrated through making use of some examples.Secondly, the path planning method in road network is studied, for its own characteristics of the optimal position query in the road network, the algorithm of the optimal path is given through combining the ideas of the optimal position query in road network with the theorem of path planning ,and the method of path planning basing on bus route is proposed, the algorithm of optimal position query in road networks is extended to the bus route planning, thereby ,the resources of public transportation is rational distribution .Finally, the algorithm was experimentally verified by analysising and comparison of experimental results through the real road network data , we can know the algorithm which is proposed in the paper ,can complete the query task quickly , and have a good practical performance.