基于粒子群算法下的交叉口信号配时优化

为了合理地优化交叉口信号配时,通过分析交叉口的评价指标,建立了以车辆的平均延误、停车次数最小、交叉口整体通行能力最大、各相位有效绿灯时间和交叉口周期时长作为约束条件的数学模型。并通过改进前人研究基础上的动态加权系数,将多目标的非线性优化问题转化为单一目标的非线性规划问题,为了得出更科学稳定的解,提出了改善粒子群算法系统稳定性的2种方法,并将其与粒子群算法结合起来。然后以Matlab为求解工具,结合临邑市某一交叉口实例进行求解分析。最后的结果表明,在使用改进后的粒子群算法进行优化后交叉口通行能力较之现状提升了9%,延误下降了28%,停车次数下降了9%,且各项优化结果均优于Webster,改进后的算法在程序中运行300代,到216代才开始收敛,而未改进的算法稳定性较差,优化结果和收敛曲线则随着实验次数的变化而变化,最后的结论证明了该算法和模型的可靠性。     

Opportunities to reduce road traffic injury: new insights from the study of urban areas

Abstract

Over the past four decades considerable efforts have been taken to mitigate the growing burden of road injury. With increasing urbanisation along with global mobility that demands not only safe but equitable, efficient and clean (reduced carbon footprint) transport, the responses to dealing with the burgeoning road traffic injury in low- and middle-income countries has become increasingly complex. In this paper, we apply unique methods to identify important strategies that could be implemented to reduce road traffic injury in the Asia-Pacific region; a region comprising large middle-income countries (China and India) that are currently in the throes of rapid motorisation. Using a convolutional neural network approach, we clustered countries containing a total of 1632 cities from around the world into groups based on urban characteristics related to road and public transport infrastructure. We then analysed 20 countries (containing 689 cities) from the Asia-Pacific region and assessed the global burden of disease attributed to road traffic injury and these various urban characteristics. This study demonstrates the utility of employing image recognition methods to discover new insights that afford urban and transport planning opportunities to mitigate road traffic injury at a regional and global scale.     

Impact of Continuous Climb Operations in ATC workload. Case-study Palma airport

This research assesses the impact of the integration of Continuous Climb operations (CCOs) on Air Traffic Control (ATC) workload. The methodology encompasses different modules: CCO, standard departing and arriving trajectories extracted from an external database, an ad-hoc algorithm for detecting and solving conflicts, and an ATC-workload model with the inclusion of CCO-task modifications. Monte Carlo simulations evaluates different combinations of these modules. Then, a sensitivity analysis is performed to evaluate two parameters: the impact of the calibration of the maximum ATC workload and the percentage increase of the CCO tasks on the ATC workload. The methodology is applied to a case study at Palma airport in Spain. Extensive numerical simulations are executed based on the integration of CCOs into the system from 0% to 100%. The integration of CCOs implies the increase of the ATC workload in the Control Tower (TWR) and the reduction in the Approach Control Centre (APP). The sensitivity analysis shows that the decrease in the increase of CCO-task workload barely affects the number of CCOs that can be operated without exceeding the workload limits. Conversely, the reduction of the ATC workload calibration allows the integration of CCOs around 50% in the case of 90% TWR calibration and up to 100% in the case of 80%.     

Collaborative delay management towards demand-capacity balancing within User Driven Prioritisation Process

The concept of User Driven Prioritisation Process (UDPP) was introduced to give Airspace Users (AUs) more flexibility under demand-capacity imbalance. This paper presents two UDPP-DCB models, built on the UDPP principle, using the Selective Flight Protection (SFP) approach to minimize the total delay cost. AUs are enabled to adapt their operations in a more cost-efficient way in the presence of capacity constraints in airspace, optimizing their flights to keep the priorities track. Then, ATFM integrates the AUs’ decision to reassign the time slots and the preferred rerouting trajectories. Results suggest that the delay cost for AUs can be largely reduced through applying the UDPP-DCB models proposed in this paper, while allowing rerouting proves effective in reducing the system delay cost.     

上海市交通拥堵成本测算及对策研究

依据美国德克萨斯运输学院交通拥挤外部成本的经典测算模型，将交通运输拥挤成本分为时间延误成本、额外燃油消耗成本、环境污染物排放成本和噪音成本三个方面，对于2015年上海市工作日高峰期交通拥挤的外部成本进行了详细的测算。结果表明，交通拥堵的外部成本约占当年上海市GDP的0.63%。最后，对于交通拥堵成本较高的现状提出了包括对上海市部分高度拥堵路段或区域收取拥堵费、大力发展上海市公共交通和发展交通快慢型出行方式共存在内的相关政策和建议。     

低碳经济下企业环境会计研究

以低碳经济为切入点,分析低碳经济下我国企业环境会计的现状和问题,探讨实施环境会计的必要性和我国企业环境会计核算面临的新问题,并在此基础上,阐述了低碳经济下实施企业环境会计的意义,提出完善我国企业环境会计的相关对策。     

关于优化流量经营管理的思考

本文将以中国移动为研究对象,针对流量经营管理作出分析思考。     

浅述交通工程基础建设招投标中资金时间价值对工程费用的影响

本文作者分析了在当前交通工程基础建设招投标中选择不同招标方案,对工程费用的影响,将资金时间价值观引入工程建设计量当中,分别从业主角度、承包商的角度出发对招投标的选择做出了初步分析。     

智能通行证管理平台构建

随着经济的快速发展和汽车保有量的迅速增长,各类单位基于安全性的管理,可能每辆汽车都配有很多不同地点的通行证,如何放置和管理这些通行证,并制订更加合理有效的管理策略是本论文所要解决的问题.针对通行证的授权管理及显示所遇到的问题,本论文基于GPS技术、信息技术、液晶屏显示技术提出了一种新的智能通行证管理平台的构建,为解决各类通行证授权及其显示方式提出新的方案.