距离约束在出租车客流网络结构中的作用研究

Role of Distance Constraint in the Structure of Taxi Passenger Flow Network

基于轨迹数据的提取与分析,发现出租车客流存在距离约束。建立包含距离约束的流量演化模型,生成模拟网络,并对不同约束参数下的网络结构进行比较分析,分析结果显示:距离约束导致网络的度分布、流量强度分布、距离强度分布等产生"截断"现象,并且约束距离越小,"截断"现象越明显。随着约束距离的减小,边权分布的衰减速度变慢。度流量强度相关性、度距离强度相关性整体呈现幂律相关,并且随着约束距离的减小,幂指数逐步增大。随着约束距离的减小,节点之间流量强度从微弱的负相关逐步转为微弱的正相关。研究结果有助于揭示人群移动的距离依赖性对出租车客流网络结构的影响规律。

By analyzing the floating taxi trajectory data, the existence of distance constraint in taxi passenger flow is found. Flow evolution model considering distance constraint is proposed and networks for different constraint parameters are simulated and compared. The results indicate that the distance constraint contributes to a ＂cut-off＂ of degree distribution, weight strength distribution, distance strength distribution, and a shorter distance constraint leads a more pronounced ＂cut-off＂. With the decrease of constrained distance, the decaying rate of edge weight distribution slows down. Both degree-weight strength correlation and degree-distance strength correlation are power-law relations, and the exponents increase with the decrease of constrained distance. As the constrained distance decrease, the assortative mixing for weight strength of nodes changes from negligible negative correlation to positive correlation. These results help to reveal the effecting principles of the distance constraint of population travels on the structure of taxi passenger flow network.