Monitoring And Continuous Search Of Best Region In Road Networks

Due to the increase of mobile devices and the rapid development of GPS technology,it has generated a large amount of points of interest with time,text and location,etc.With the help of the GIS,many spatial location queries have received wide attention.Best region search(BRS)is an important location query problem that return the optimal locations which satisfy the objective function for the user.Recently,the BRS problem has been extensively studied.Considering the mobility of the objects,in this paper,we study the monitoring and continuous BRS problems in road network.Firstly,for the objects in the data stream environment,the monitoring of the best region in the road networks(MBRS)is proposed.The MBRS problem requires that the optimal solution at different times should be returned based on the location information of the objects in the data stream,which can support many real-life query problems,such as human flow tracking and traffic analysis.In this paper,a native method is proposed to solve the MBRS problem.After that,effective pruning rules and a branch-and-bound algorithm are proposed to update the results at different times,which are based on the preprocessing of road network.Secondly,for the continuously moving objects on the road network,the continuous best region search in the road network(Co-BRS)is proposed.The Co-BRS problem requires re-finding the best region when the optimal solution may change.In this paper,three events are proposed as criteria for discretizing continuous time,and the position and the state of the object are updated at each discrete time.In addition,in order to reduce the space and the number of objects to be processed in the update process as much as possible,a storage structure with prunning and an incremental update algorithm are proposed.Finally,the effectiveness and feasibility of the proposed algorithm are verified by analyzing the experimental results on different datasets.