Continuous k adjacent query method in time dependence road network

Abstract

The invention relates to a continuous k adjacent query method in a time dependence road network. The method comprises the steps that at the offline stage, a potential 1NN result area is pre-calculatedfor each interest point, when a query is initiated, the potential 1NN result area intersecting with the minimum wrapping rectangle composed of each pair of adjacent end points on a designated path issearched for at first, and the interest point corresponding to the potential 1NN result area is added to a result candidate set; then departure time of the designated path and weight functions of corresponding edges can be used for calculating arrival time of each end point on the designated path; according to the movement direction of query points, a function model from the query points to all the interest points in the candidate set is established for each sub path; finally, according to the function models, time and space break points of k adjacent result change and corresponding k adjacent results can be effectively found. According to the continuous k adjacent query method, the interest point result candidate set which possibly becomes a result can be quickly retrieved, then the timebreak points are divided according to the function models, and continuous k adjacent query in the time dependence road network can be effectively achieved.

Description

technical field [0001] The invention belongs to the technical field of neighbor query, and specifically relates to a continuous k-nearest neighbor query method in a time-dependent road network, which implements the continuous k-nearest neighbor query technology in the time-dependent road network by using the fastest travel time function model algorithm from a query point to a point of interest. Background technique [0002] With the development of networks, the popularity of mobile terminals, the rapid progress of online map services and their widespread deployment in handheld devices and car navigation systems have led to the widespread use of location-based services. This is of great help to government decision-making, corporate interests, and personal convenience. For example, it provides decision-making assistance for government units in the allocation of transportation, medical and other resources; it provides relevant information for enterprise logistics management and...

AI Technical Summary

Problems solved by technology

Although these methods can solve the difficulty of constantly changing edge weights, they cannot solve the problem of constantly moving query points.

IE (Intersection examination), UBA (UpperBound Algorithm), UNICONS (a unique continuous search algorithm), DAR and DAR, VCkNN and other methods solve the continuous k-nearest neighbor query of the specified path in the static road network, but these methods all assume the weight of the edge The value is constant and cannot be applied to continuous k-nearest neighbor queries in time-dependent road networks where edge weights are constantly changing

Images