Research On Continuous Nearest Neighbor Query

In the second half of the20th century, the world has entered the information age.With the tremendous advances in science and technology, especially computerinventions and unstopping improvement, the impact of the information on wholesociety is improved to an indispensable position. Because of the amount information,dissemination of information and the increase speed of information processing speedgeometrically, which requires new theories to be applied to modern life increasinglyfast, spatio-temporal database is created on this background.Nearest neighbor query problem as temporal databases has been an importantresearch direction with a lot of attention, mainly due to the nearest neighbor queriesand is closely related to our life. Finding the nearest bank is a nice application forthis kind of query. Through this example we can see that the nearest neighbor has itslimitations in that the location of the query point can not change continuously. Tocompensate for this shortcoming, continuous nearest neighbor query, is proposed, inwhich all the nearest neighbors satisfying condition on the road one passes can befound out and the split points where nearest neighbor changed are given.Firstly, the structure and operation of the R tree index, the nearest neighbordistance measurement concepts are given. With the use the properties of R-tree, the knearest neighbor algorithm is proposed. Secondly, the continuous nearest neighborproblem in roads is studied. The concept of continuous nearest neighbor query isgiven, and then divide it down to two different static and dynamic theories, makinguse of the concept of intermediate nodes, storage space points by regulararrangement avoids the query process many unwanted access, so that efficiency isimproved. Finally, the road information to build a tree structure for the road networkin each road is assigned a weight, based on the real-time road traffic information todetermine road conditions to change the size of the weights. When a section of theright value is too large, the representative of the time spent by this road too, so giveup this path, choose another smooth roads, thus ensuring the destination within theexpected time.