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Research On Line Segment Aggregate Nearest Neighbor Query Method In Spatial Database

Posted on:2021-01-06Degree:MasterType:Thesis
Country:ChinaCandidate:D K LiangFull Text:PDF
GTID:2428330605972986Subject:Computer technology
Abstract/Summary:PDF Full Text Request
In recent years,with the rapid development of global positioning system and Internet mobile research technologies,the demand for location-based information services has become higher and higher.Therefore,spatial data query technology has become more and more important.In the spatial database query technology,the nearest neighbor query plays an important role.However,the existing nearest neighbor query methods cannot effectively deal with all query requirements based on line segment objects in real life.Line segment neighbor query has become a difficult problem in complex environments.At present,the existing academic research schemes cannot effectively solve the problem of nearest neighbor query of line segments in road network environment and obstacle environment,this paper focuses on the method of line segment aggregate nearest neighbor query based on road network environment and obstacle environment in spatial database.Firstly,the method of line segment aggregate nearest neighbor query based on Voronoi diagram of network segment in road network environment is studied.In the filtering process,based on the properties of the network line Voronoi diagram and the geometric characteristics of the network line influence area,the data line segments that are not likely to be the result are removed directionly to obtain the candidate set.During the refining process,according to the position relationship between the line segments,the distance between the line segments is calculated,and the query result is further obtained,improves query efficiency.Furthermore,in order to solve the problem of line segment k aggregate nearest neighbor query in obstacle environment,a line segment k aggregate nearest neighbor query method in obstacle environment based on line Voronoi diagram is proposed.In the filtering process,according to the the definition of the line obstacle distance,the definition of the line segment k aggregate nearestneighbor of the in the obstacle environment and the nature of the line segment Voronoi diagram,the data line segments that are not likely to be the result are removed directionly to obtain the candidate set.In the refining process,the scope of the query is further reduced,and the final query result is obtained through calculation,reduces the time required for inquiries...
Keywords/Search Tags:aggregate nearest neighbor, line segment, road network environment, obstacle environment, k aggregate nearest neighbor
PDF Full Text Request
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