有向线对象细节拓扑关系模型

轨迹在地理空间中相对一条有向线移动时，可能发生多次进入、离开、穿过、相遇、折返、停留等拓扑关系。针对轨迹-有向线的时空关联特征，提出语义关联的轨迹-有向线移动过程模型:基本思路是将轨迹-有向线的复杂拓扑细节描述为若干局部拓扑关系的组合，从拓扑和语义的角度描述轨迹相对于有向线的移动过程。最后设计并实现了面向该模型的关系模式，并以两类典型请求为例，分析了轨迹-有向线移动过程的纯SQL查询分析技术。

T-Drive: Enhancing Driving Directions with Taxi Drivers' Intelligence

Trajectories move relative to directed lines, incurring topological events of various kinds, such as entries, departures, crosses, meets, retracements, stops and so on. Based on the spatial-temporal characteristics of trajectory-directed line movements a semantic associated model of trajectory-directed line movement is proposed, Our strategy depicts complex detailed topological relations between trajectories and directed lines by combining sets of local topological relations. In this way, movements of trajectories with respect to directed lines can be specified from the perspective of both topology and semantics. A relational schema based on this model was designed and evaluated in for two cases of typical queries types and analyzing trajectory-directed line movement by exploring pure SQL statements.