VID 连接: 建立轨迹和兴趣点之间的映射以支持基于位置的服务

Variable Influence Duration (VID) join is a novel spatio-temporal join operation between a set T of trajectories and a set P of spatial points. Here, trajectories are traveling history of moving objects (eg, travelers), and spatial points are POIs (eg, restaurants). VID join returns all pairs of (τ s, p) if τ s is spatially close to p for a long period of time, where τ s is a segment of trajectory τ∈ T and p∈ P. Each returned (τ s, p) implies that the moving object associated with τ s stayed at p (eg, having dinner at a restaurant). Such information is useful in many aspects, such as targeted advertising, social security, and social activity analysis. The concepts of influence and influence duration are introduced to measure the spatial closeness between τ s and p, and the time spanned, respectively. Compared to the conventional spatio-temporal join, the VID join is more challenging since the join condition varies for different POIs, and the …