一种基于路网的连续最近邻查询算法.doc

一种基于路网的连续最近邻查询算法摘要: 在路网中,连续最近邻( Continuous Nearest Neighbor , CNN ) 查询在基于位置的服务中尤为关键。现有的查询处理方法大多依赖于路网中查询对象的分布密度, 其他处理方法如 UNICONS 等改进了这些不足。然而在查询对象密集分布的路网中, 存在无效计算最近邻( Nearest Neighbor , NN )的问题。针对这个问题,本文提出并证明了非交叉点子路径中的预计算方法, N 查询算法。该算法利用分治法以交叉点为划分依据, 将查询路径划分成子路径, 然后对子路径中的结点进行 NN 查询, 从而降低了 NN 查询的计算代价。通过实验,N 查询中的正确性和有效性,性能优势尤为明显。关键词: 连续最近邻查询;基于位置的服务; UNICONS ;预计算方法;分治算法 Algorithm for C NN Query over work Wang Heng 1,2 Ying-Yuan Xiao 1,2 Tianjin Key Laboratory of puting and Novel Software Technology, Tianjin University of Technology , 300384, Tianjin Key Laboratory puter Vision and System ( Tianjin University of Technology ), Ministry of Education, 300384, Tianjin Abstract In work ( RN ), Continuous Nearest Neighbor (C NN) query frequently used in Location-Based Services (LBS). The majority of the existing works onC NN queries are largely affected by the density of objects of interest , others such as UNICONS e these problems , yet there may be over-calculating problem . In this paper , we propose and proof a putation theory based on non- intersection path , and then presented an algorithm N query, which uses divide and conquer method to query NN on sub path , where is divided the query path into sub path based on non-intersection points, and then to reduce putational cost. Experimental results show that our processing approach in N query is correct and effective, especially the res