cknn query method for moving objects in road network based on rrn-tree
A technology for moving objects and road networks, applied in the field of data query, can solve problems such as low query efficiency, inability to solve the problem of nearest neighbor query in complex road networks, and inability to reflect the turning relationship of moving objects, and achieve the effect of improving performance.
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
Method used
Image
Examples
specific Embodiment approach 1
[0042] Specific implementation mode one: the following combination Figure 1 to Figure 12 Describe this embodiment, the RRN-Tree-based mobile object CKNN query method in the road network described in this embodiment, the implementation steps of this query method are:
[0043] Step 1: First, define road network G, route r, road segment seg, intersection j, moving object o and KNN monitoring area respectively;
[0044] Described road network G is a two-tuple G=(R, J), and wherein R is the set of routes in the road network, and each route comprises several road sections, and J is the set of intersections of multiple routes in the road network;
[0045] The route r refers to a complete path that can be named independently in the road network, and is defined as:
[0046] r = ( r i d , l e n , ( ...
specific Embodiment approach 2
[0066] Specific implementation mode two: the following combination Figure 1 to Figure 12 Describe this embodiment, this embodiment is a further description of Embodiment 1, the specific implementation process of the KNN query initial set calculation described in step 3 described in this embodiment is:
[0067] First, establish a priority queue PQueue to save the adjacent points in the query process. The elements in the priority queue PQueue are sorted according to the distance from the query point from small to large, and the initial value of the priority queue PQueue is empty;
[0068] Establish a queue ResultList for storing query results, the length of the queue ResultList is K, the elements in the queue are arranged in ascending order according to the distance from the query point, and the initial value of the queue ResultList is empty;
[0069] When sending a query request, let q represent the query point, o i Indicates the point of interest to be queried, where i is a ...
specific Embodiment approach 3
[0074] Specific implementation mode three: the following combination Figure 1 to Figure 12 Describe this embodiment. This embodiment is a further description of Embodiment 1. The CKNN query update in Step 3 described in this embodiment is divided into two cases. When the position of the query point object remains unchanged, but the POI object moves When , the KNN monitoring area generated by the query process can reduce the query update cost. The realization process is as follows:
[0075] When the query point object does not move, since the position of the query object remains unchanged, the KNN monitoring area generated by the last query also remains unchanged. Three cases are handled separately:
[0076] 1. When the interest point object K′=K falling into the KNN monitoring area, it is only necessary to find all the moving objects on the road sections in the KNN monitoring area through RRN-Tree, and use the object set on the road section in the KNN monitoring area as res...
PUM
Login to View More Abstract
Description
Claims
Application Information
Login to View More