• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Transportation Research Part B: Methodological >On the spatial partitioning of urban transportation networks
【24h】

On the spatial partitioning of urban transportation networks

机译：论城市交通网络的空间划分

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

It has been recently shown that a macroscopic fundamental diagram (MFD) linking space-mean network flow, density and speed exists in the urban transportation networks under some conditions. An MFD is further well defined if the network is homogeneous with links of similar properties. This collective behavior concept can also be utilized to introduce simple control strategies to improve mobility in homogeneous city centers without the need for details in individual links. However many real urban transportation networks are heterogeneous with different levels of congestion. In order to study the existence of MFD and the feasibility of simple control strategies to improve network performance in heteroge-neously congested networks, this paper focuses on the clustering of transportation networks based on the spatial features of congestion during a specific time period. Insights are provided on how to extend this framework in the dynamic case. The objectives of partitioning are to obtain (i) small variance of link densities within a cluster which increases the network flow for the same average density and (ii) spatial compactness of each cluster which makes feasible the application of perimeter control strategies. Therefore, a partitioning mechanism which consists of three consecutive algorithms, is designed to minimize the variance of link densities while maintaining the spatial compactness of the clusters. Firstly, an over segmenting of the network is provided by a sophisticated algorithm (Normalized Cut). Secondly, a merging algorithm is developed based on initial segmenting and a rough partitioning of the network is obtained. Finally, a boundary adjustment algorithm is designed to further improve the quality of partitioning by decreasing the variance of link densities while keeping the spatial compactness of the clusters. In addition, both density variance and shape smoothness metrics are introduced to identify the desired number of clusters and evaluate the partitioning results. These results show that both the objectives of small variance and spatial compactness can be achieved with this partitioning mechanism. A simulation in a real urban transportation network further demonstrates the superiority of the proposed method in effectiveness and robustness compared with other clustering algorithms.
机译：最近显示，在某些条件下，城市交通网络中存在将空间均值网络流量，密度和速度联系起来的宏观基本图（MFD）。如果网络具有相似属性的链接是同质的，则可以进一步定义MFD。这种集体行为概念也可以用来引入简单的控制策略，以提高同质城市中心的机动性，而无需个别链接中的细节。但是，许多实际的城市交通网络在拥挤程度不同的情况下是异构的。为了研究MFD的存在以及采用简单控制策略来改善异构拥塞网络中网络性能的可行性，本文基于特定时间段内拥塞的空间特征，重点研究了交通网络的聚类。提供了有关如何在动态情况下扩展此框架的见解。分区的目的是获得（i）集群内链路密度的小变化，从而在相同的平均密度下增加网络流量，以及（ii）每个集群的空间紧凑性，这使得周边控制策略的应用成为可能。因此，设计了一种由三个连续算法组成的分区机制，以最大程度地减小链路密度的变化，同时保持群集的空间紧凑性。首先，通过复杂的算法（归一化剪切）提供网络的过度分割。其次，基于初始分割开发了一种合并算法，并获得了网络的粗略划分。最后，设计了一种边界调整算法，以通过降低链接密度的方差并同时保持群集的空间紧凑性来进一步提高分区质量。此外，还引入了密度方差和形状平滑度指标，以识别所需的簇数并评估分区结果。这些结果表明，使用这种划分机制既可以实现小方差又可以实现空间紧凑的目的。在实际的城市交通网络中的仿真进一步证明了与其他聚类算法相比，该方法在有效性和鲁棒性方面的优越性。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号