Discovering Popular Routes from Trajectories 从轨迹中发现热门路线 分享人：J-JaSon Conference ICDE 2011 International Conference on Data Engineering School & Author School & Author The aim Discovering the Most Popular Route between two locations by observing behaviors of many previous users. 通过观察之前用户的行为，找出两地之间最热门的路线 Why do this How do this How do this Three steps: How do this Three steps: How do this Three steps: Related Work Step 1 Mining Transfer Network Mining Transfer Network Notice that if there is a road map available, we can find out the transfer network by map-matching trajectories. Mining Transfer Network Detect the intersections of trajectories Intersections of trajectories Within an intersection region, the density of trajectory points is normally higher, in comparison with the density of points on an incoming/outgoing road edge, because it is the place where trajectories join together or drivers slow down to make a turn. If we consider an intersection as a group of points, then the size of the group should be greater than some threshold. Intersections of trajectories A number of trajectories change moving direction at an intersection, as some people make turns. The moving directions of trajectory points from/to different road edges are likely to be orthogonal (i.e., angle of difference tends to ??/2). Within a small distance, points whose moving directions differ by 0 or ?? (i.e., in the same or opposite direction) are probably on the same road, while points with direction difference>0 and <?? are possibly moving to different road branches of an intersection. The closer the angle of difference tends to ??/2, the higher possibility that an intersection exists. 。。。以下略