To determine the dynamic influence range of emergencies under special events, the spacial and temporal characteristics of the traffic flow are studied by simulation based on the cell transmission model （CTM）. Based ...To determine the dynamic influence range of emergencies under special events, the spacial and temporal characteristics of the traffic flow are studied by simulation based on the cell transmission model （CTM）. Based on the traffic management measures used under special events, a semi-dynamic assignment algorithm is proposed, which is combined with an algorithm for logit multi-path traffic assignment and the CTM. In a simple calculation network, the spacial and temporal characteristics of traffic flows which vary with different traffic management schemes are studied, and a method to obtain the influence range of emergency is proposed by computing the jam time of the intersections. By contrasting the average delay of each vehicle, the dissipation effect is studied under two different traffic management schemes. The example shows that the spatial and temporal variety of the traffic flow can be easily simulated and the influence range of emergency can be confirmed by the method based on the CTM. The proposed method provides a new idea for decision-making on traffic management under emergency under special events.展开更多
[目的/意义]针对CTM模型与K-means算法在文本聚类中存在的不足,提出将二者融合的CKM算法。该算法利用CTM模型确定聚类数和初始聚类中心,利用K-means算法进行聚类。[方法/过程]以Web of Science为数据来源,建立涵盖6个主题的多学科文献集...[目的/意义]针对CTM模型与K-means算法在文本聚类中存在的不足,提出将二者融合的CKM算法。该算法利用CTM模型确定聚类数和初始聚类中心,利用K-means算法进行聚类。[方法/过程]以Web of Science为数据来源,建立涵盖6个主题的多学科文献集,以F值为评价指标,利用R语言中的k-means函数和topicmodels包,比较K-means算法、CTM模型、CKM算法的聚类效果。[结果 /结论]结果表明,与单纯使用K-means算法、CTM模型相比,CKM算法的聚类效果更优,稳定性更好。展开更多
为调整不同路段的限速值,平滑交通流,从而提升高速公路车辆通行的安全性和效率,针对交通瓶颈区设计一种基于深度强化学习的平滑车速管控系统。该系统主要包含动态限速启动、限速值确定与更新和情报板动态发布等3个模块。将深度强化学习...为调整不同路段的限速值,平滑交通流,从而提升高速公路车辆通行的安全性和效率,针对交通瓶颈区设计一种基于深度强化学习的平滑车速管控系统。该系统主要包含动态限速启动、限速值确定与更新和情报板动态发布等3个模块。将深度强化学习算法DDQN(Double Deep Q-Network)引入系统中,提出一种基于DDQN的平滑车速控制策略,从目标网络和经验回顾2个维度提升该算法的性能。基于元胞传输模型(Cellular Transmission Model,CTM)对宁夏高速公路某路段的交通流运行场景进行仿真,以车辆总通行时间和车流量为评价指标验证该系统的有效性,结果表明该系统能提高瓶颈区内拥堵路段车辆的通行效率。展开更多
基金The National High Technology Research and Development Program of China(863 Program)(No.2007AA11Z210)
文摘To determine the dynamic influence range of emergencies under special events, the spacial and temporal characteristics of the traffic flow are studied by simulation based on the cell transmission model （CTM）. Based on the traffic management measures used under special events, a semi-dynamic assignment algorithm is proposed, which is combined with an algorithm for logit multi-path traffic assignment and the CTM. In a simple calculation network, the spacial and temporal characteristics of traffic flows which vary with different traffic management schemes are studied, and a method to obtain the influence range of emergency is proposed by computing the jam time of the intersections. By contrasting the average delay of each vehicle, the dissipation effect is studied under two different traffic management schemes. The example shows that the spatial and temporal variety of the traffic flow can be easily simulated and the influence range of emergency can be confirmed by the method based on the CTM. The proposed method provides a new idea for decision-making on traffic management under emergency under special events.
文摘[目的/意义]针对CTM模型与K-means算法在文本聚类中存在的不足,提出将二者融合的CKM算法。该算法利用CTM模型确定聚类数和初始聚类中心,利用K-means算法进行聚类。[方法/过程]以Web of Science为数据来源,建立涵盖6个主题的多学科文献集,以F值为评价指标,利用R语言中的k-means函数和topicmodels包,比较K-means算法、CTM模型、CKM算法的聚类效果。[结果 /结论]结果表明,与单纯使用K-means算法、CTM模型相比,CKM算法的聚类效果更优,稳定性更好。
文摘为调整不同路段的限速值,平滑交通流,从而提升高速公路车辆通行的安全性和效率,针对交通瓶颈区设计一种基于深度强化学习的平滑车速管控系统。该系统主要包含动态限速启动、限速值确定与更新和情报板动态发布等3个模块。将深度强化学习算法DDQN(Double Deep Q-Network)引入系统中,提出一种基于DDQN的平滑车速控制策略,从目标网络和经验回顾2个维度提升该算法的性能。基于元胞传输模型(Cellular Transmission Model,CTM)对宁夏高速公路某路段的交通流运行场景进行仿真,以车辆总通行时间和车流量为评价指标验证该系统的有效性,结果表明该系统能提高瓶颈区内拥堵路段车辆的通行效率。
