Kwon Yungi, Jung Jung-Hoon, Eom Young-Ho
Natural Science Research Institute, University of Seoul, Seoul 02504, Republic of Korea.
Department of Physics, University of Seoul, Seoul 02504, Republic of Korea.
Chaos. 2023 Nov 1;33(11). doi: 10.1063/5.0150217.
Making the connection between the function and structure of networked systems is one of the fundamental issues in complex systems and network science. Urban traffic flows are related to various problems in cities and can be represented as a network of local traffic flows. To identify an empirical relation between the function and network structure of urban traffic flows, we construct a time-varying traffic flow network of a megacity, Seoul, and analyze its global efficiency with a percolation-based approach. Comparing the real-world traffic flow network with its corresponding null-model network having a randomized structure, we show that the real-world network is less efficient than its null-model network during rush hour, yet more efficient during non-rush hour. We observe that in the real-world network, links with the highest betweenness tend to have lower quality during rush hour compared to links with lower betweenness, but higher quality during non-rush hour. Since the top betweenness links tend to be the bridges that connect the network together, their congestion has a stronger impact on the network's global efficiency. Our results suggest that the spatial structure of traffic flow networks is important to understand their function.
建立网络系统的功能与结构之间的联系是复杂系统和网络科学中的基本问题之一。城市交通流与城市中的各种问题相关，并且可以表示为局部交通流的网络。为了确定城市交通流的功能与网络结构之间的经验关系，我们构建了一个特大城市首尔的时变交通流网络，并采用基于渗流的方法分析其全局效率。通过将现实世界的交通流网络与其具有随机结构的相应零模型网络进行比较，我们发现现实世界的网络在高峰时段比其零模型网络效率更低，但在非高峰时段效率更高。我们观察到，在现实世界的网络中，与介数较低的链路相比，介数最高的链路在高峰时段往往质量较低，但在非高峰时段质量较高。由于介数最高的链路往往是将网络连接在一起的桥梁，它们的拥堵对网络的全局效率有更强的影响。我们的结果表明，交通流网络的空间结构对于理解其功能很重要。
