Trajectory Query Based On Traveling Time

With the continuous proliferation of GPS-enabled devices and the rapid development of mobile devices,a large amount of location-based applications have been studied extensively.Under this,one prominent applications is interesting trajectories search.Traditional trajectory query retrieves trajectories either by locations or by a trajectory,and then returns trajectories that are geographically close to a set of query locations or the most similar trajectory to the query trajectory.With the further study of trajectories,location-based trajectory query,paying more attention to trajectory query by combining time information,is no longer limited to search for trajectories which are geographically close to the query points only.Therefore,in order to further meet the needs of users,this paper dose some research on trajectory query based on traveling time.First of all,proposing a trajectory query based on origin and destination.The query returns trajectories from historical trajectories which pass a given pair of origin and destination at a given departure time.In the algorithm,any point of the trajectories can be matched with the origin and destination,thereby increasing the number of available trajectories,but also increasing the workload of the query.Therefore,in order to improve the efficiency of the query,three sets of time range are computed for the given departure time,and trajectories are pruned effectively with the help of trajectories information recorded in the grid indexes.Next,for querying trajectories by locations,most of the existing works retrieving trajectories that are geographically close to a set of query locations while neglecting road conditions and traveling time information.However,in many real applications,the set of geographically close trajectories may not be the best choice due to rough road conditions,and we should also regard traveling time information as an important factor.In order to further improve the existing trajectory query,this paper propose and investigate a novel trajectory query,Top-k Trajectory Query based on Traveling Time,which aims at retrieving the Top-k trajectories ranked by traveling time according to the locations which users are interested in.In order to improve the efficiency of the algorithm,this paper propose the concept of the set of effective points and matching points,as well as threekinds of termination rules.Finally,empirical analysis on data set verifies the validity of our approaches.