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Range-constrained Spatial Keyword Search On Road Network

Posted on:2018-10-01Degree:MasterType:Thesis
Country:ChinaCandidate:S Y LiFull Text:PDF
GTID:2348330533463393Subject:Computer Science and Technology
Abstract/Summary:PDF Full Text Request
With the rapid development of geographic positioning technology,spatial information retrieval plays a very important role in many applications,and spatial keyword search has become a hot research topic in database community,which considers both spatial proximity to the query location and textual relevance to the query keywords.Taking into account that people's daily life is carried out along the road network,the study of spatial keyword search has been gradually extended from European space to networks.In addition,users sometimes do not want to query the objects near the current location,but the objects which have a certain distance to the query point.Therefore,in order to meet the needs of users,this paper does some research on range constrained spatial keyword search.Firstly,for the situation in which the users want all the requirements to be satisfied by an object,this paper propose a range constrained top-k spatial keyword query algorithm.This algorithm returns k objects which within the constrain range R,satisfies the requirement of the keywords,and nearest to the query point.In order to improve the query speed,we build a grid index with inverted list for objects in road network.When a query is executed,using the grid index can effectively lock the range R.In addition,the algorithm use labels to calculate shortest distance between the query point and an object.Secondly,for the situation in which users' requirements need multiple objects to meet,we study the range constrained collective spatial keyword query processing on road network.In the process of query,we use the grid index and label to improve the efficiency.In addition,since the query is a NP-complete problem,this paper presents an approximate algorithm and an exact algorithm to solve the problem.Finally,experiments and tests on a real road network dataset demonstrate the efficiency and accuracy of our presented algorithms.
Keywords/Search Tags:Road network, Spatial keyword search, Range-constrained, Grid, Label
PDF Full Text Request
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