城市轨道交通网络演化特性分析

Analysis of Evolution Characteristics of Urban Rail Transit Network

城市轨道交通网络增长方式及连接机制对网络结构及性能有重要影响,为了解其演化规律,本文以北京等五个城市为研究对象,建立以线路为演化单位的轨道交通演化网络模型。基于网络理论,本文首先通过对平均度、平均最短路径等指标的计算对网络复杂性进行分析;其次,通过K-S检验及数据拟合对网络无标度特性进行分析,挖掘换乘节点偏好选择机制,并引入相对度值熵衡量网络结构匀质性;最后,通过攻击节点分析网络抗毁性。研究结果表明:我国主要城市轨道交通网络复杂性相对较低。换乘节点选择机制并非完全为“择优连接”。网络表现出面对随机攻击时抗毁性较强,而蓄意攻击时较弱的特点,但随网络演化表现出稳定的趋势。

The growth mode and connection mechanism of urban rail transit network have an important influence on network structure and performance.In order to understand the law of network evolution,we take Beijing and other four urban rail transit networks as research objects,and establish a rail transit evolution network model with lines as the evolution unit.Based on the complex network theory,we first analyzes the network complexity by calculating the average degree and average shortest path and other indicators.Secondly,through K-S test and data fitting,the scale-free characteristics of the network are analyzed,and the driving mechanism of selecting new transfer nodes is mined,and the relative degree value entropy is introduced to measure the homogeneity of the network structure.Finally,by attacking nodes,the change of network invulnerability is simulated.The results show that the complexity of rail transit network in major cities in China is relatively low.The transfer node selection mechanism is not completely'preferred connection'.Network invulnerability is strong when faced with random attacks,weak when faced with deliberate attacks,but it becomes stable with the increase of scale.