快速路可变限速与匝道控制协同优化策略

可变限速控制和匝道控制是快速路交通控制的主要手段,本文对两者的协同优化策略进行了研究.借助智能车路协同系统强大的信息感知能力,通过引入微观交通流信息,对经典METANET模型进行了改造,构建了可变限速控制影响下的微观METANET模型,实现了一种新的可变限速控制策略,同时,采用ALINEA算法,对入口匝道进行了优化控制,实现了两者的协同优化.最后,基于实际道路和交通流数据搭建了仿真平台,对微观METANET模型和协同优化策略的有效性进行了验证.仿真结果表明,微观METANET模型具有良好的交通流预测效果,协同优化策略能有效地改善快速路交通流状态.     

Challenges and Benefits in the Design of Coastal Walking and Cycling Amenities: Toward a More Integrated Coastal Management Approach

The planning and development of pedestrian and cycling amenities in coastal urban environments is a challenging process because a wide range of policies and considerations must be taken into account. Among these, the concepts of sustainability and more recently, resilience, have been gaining prominence. Green Infrastructure design approaches can integrate aspects of both sustainability and resilience, providing multiple services within single development projects. This study focuses on Dublin and examines a range of amenity projects at various stages of development that relate to the provision of new coastal walking and/or cycle routes. These are initially contextualized at the city level before focusing specifically on challenges and benefits associated with the design and implementation of such projects. Based on our findings, recommendations are made for optimizing the potential of future projects to effectively integrate with other initiatives so as to deliver broader policy objectives. A simple sequential model is presented that should assist developers and decision-makers to take a more integrated, multidisciplinary approach to meeting policy goals when planning and developing coastal amenities. Finally, this is remodeled into a set of considerations that are generally applicable to coastal development proposals of significant scale.     

Expertise in decision-making for large infrastructure projects: from UK trunk roads to High Speed Rail 2

At the decision-making stage, a large-scale infrastructure project is essentially a broad concept, and this means the expert analyses will differ from each other and become contested over time, leading to the emergence of rival narratives. It is only where there is a limited range of expert analyses that the bases for decision-making will remain relatively clear-cut. Over time the contested nature of expertise can significantly inhibit the construction of effective narratives, either for or against the project, and also make decision-making more complex and problematic. Decision makers may also seek greater clarification through the construction of narratives that rise above these disputed areas of expertise, and the scientific evidence becomes less important. This paper examines the changing nature of contested expertise through a comparative analysis of political decision-making between UK trunk roads policy and the case of High Speed Rail 2, through the framework of epistemic communities.     

齿轨铁路基础设施综合维修体系研究

根据齿轨铁路的工程特点,分析齿轨铁路基础设施综合维修的相关需求。借鉴国内既有铁路的综合维修模式,提出适合齿轨铁路的综合维修模式。进而对综合维修体系的组织机构设置及具体机构布点提出了建。     

旅游交通融合发展研究——以福建省为例

为深入落实"交通强国"战略和实现"全域旅游"目标,推动旅游与交通深度融合发展,需做好旅游交通体系发展的顶层设计。通过分析旅游交通面临的问题,提出了旅游交通融合发展的理念。将福建省作为案例,针对福建旅游交通网络面临的问题,提出了"快旅慢游"旅游交通体系的建设目标、实施方案及保障措施。依托高铁、民航、邮轮和公路等综合立体交通网络,提出了"一带三环多放射"旅游交通"快旅"通道的发展思路;通过特色旅游产品开发、旅游服务质量提升等方面,规划了"慢游"微循环旅游交通的发展方案,构建了福建省多层次、综合立体的旅游交通体系发展新格局。以期通过福建省旅游交通融合发展案例研究,为其他省市旅游交通融合发展借鉴参考。     

The price of uncertainty in pavement infrastructure management planning: An integer programming approach

Currently there is a true dichotomy in the pavement maintenance and rehabilitation (M&R) literature. On the one hand, there are integer programming-based models that assume that parameters are deterministically known. On the other extreme, there are stochastic models, with the most popular class being based on the theory of Markov decision processes that are able to account for various sources of uncertainties observed in the real-world. In this paper, we present an integer programming-based alternative to account for these uncertainties. A critical feature of the proposed models is that they provide – a priori – probabilistic guarantees that the prescribed M&R decisions would result in pavement condition scores that are above their critical service levels, using minimal assumptions regarding the sources of uncertainty. By construction of the models, we can easily determine the additional budget requirements when additional sources of uncertainty are considered, starting from a fully deterministic model. We have coined this additional budget requirement the price of uncertainty to distinguish from previous related work where additional budget requirements were studied due to parameter uncertainties in stochastic models. A numerical case study presents valuable insights into the price of uncertainty and shows that it can be large.     

Analyzing passenger train arrival delays with support vector regression

We propose machine learning models that capture the relation between passenger train arrival delays and various characteristics of a railway system. Such models can be used at the tactical level to evaluate effects of various changes in a railway system on train delays. We present the first application of support vector regression in the analysis of train delays and compare its performance with the artificial neural networks which have been commonly used for such problems. Statistical comparison of the two models indicates that the support vector regression outperforms the artificial neural networks. Data for this analysis are collected from Serbian Railways and include expert opinions about the influence of infrastructure along different routes on train arrival delays.     

网格中多CA环境密钥管理方案的研究

针对网格环境中的CA认证模型,提出基于可信任第四方的密钥全托管机制,对用户密钥进行统一的托管、存取、查询和验证.该模型独立于现有的分布式CA,将密钥的管理与用户本身的密钥保密强度分离,从而最大程度地降低密钥丢失和被窃的可能性.利用上述理论,作者将密钥托管机制应用在数字图书馆的资源权限认证过程中,降低了数字图书馆用户群复杂性对数字资源安全的危害程度.     

关于我国现代物流发展的思考

在全球经济一体化和信息化的推动下.现代物流业已从原来单纯的运输业发展为以物 流企业为主体、涉及生产、流通和消费过程的现代物流系统.随着经济的发展.作为国民经济动 脉的现代物流业将越来越为各国所重视.本文在分析我国物流业发展历史和现状的荃础上.提 出了加快我国现代物流发展的几点思考.