Research On Nearest Neighbor Query Of Moving Objects With Uncertain Velocity In Road Network

With the rapid growth of the Global Positioning System and the wireless networkcommunication technology, some related new applications such as location basedservices arise. The k Nearest Neighbor (kNN) query is a kind of important query in thefield of spatial database location based services. The k nesrest neighbor query is usedto locate k objects nearest to query point.The k nearest neighbor query has the extremely vital significance in road networkas well as in Euclidean space. The velocities of moving objects are assumed to beflxed in most researches of different types of queries on road network. In fact,influenced by the uncertainty factors (e.g. external environment like road condition,individual situation and so forth), the velocities of moving objects may be varied. Inthis paper, I improse two kinds of k nearest neighbor query of moving objects withuncertain velocity in road network and the corresponding processing methods.First, this paper improses a method for k Nearest Neighbor query of movingobjects with uncertain velocity in road network. At the query time point, according tothe position of query object, the query processing gets candiate objects that havechance to be a query answer. Then compute the k nearest neighbors' subsets ofcandiate objects and their probabilities according to the probability computing method.Comparing with the traditional kNN query of moving objects with constant velocity,the kNN query imposed in this paper improves the precision of the query result.Secondly, this paper also imposes and resolves the k Range Nearest Neighbor(kRNN) query of moving objects with uncertain velocity in road network. The queryobject may be every point within a given query region. The k Range Nearest Neighborquery finds the k nearest neighbors of every point on the road segments within thequery region based on the network distance. This paper also imposes the processingalgorithm of the k Range Nearest Neighbor query of moving objects with uncertainvelocity in road network.Under the same conditions,the kRNN processing algorithmfor the moving objects with uncertain velocity imposed in this paper works better thanthe simple algorithm. Finally, the experimental results show that the two methods proposed in thispaper have good efficiency and effectiveness.