基于潮汐交通的可变车道分流带设置研究

为了提高潮汐交通道路的安全度,基于南京市虎踞路调查的交通数据,分析其潮汐交通特性,针对潮汐路段提出优化设计方案,在可变车道内,分析车辆的速度、道路宽度以及汽车转弯半径对分流带长度的影响,利用切函数与约束函数,设计一定长度的自动可移动式分流带。利用交通微观仿真平台vissim对实施协调控制后的结果进行仿真实验,结果表明控制后的车头间距增大,通行效率得到提高,安全度提高。     

我国产业关联外溢的实证研究——基于交通设备制造业的数据

经济系统中各个产业之间存在着关联,而一国各个产业之间的关联,部分外溢为国内产业与国外产业之间的关联,即存在着产业关联外溢的问题。本文基于中国交通设备制造业的数据,分析2002-2010年该产业在投入产出表中的相关变化,测算该产业及其产业关联外溢对中国经济增长的效应;并进一步考察了产业关联外溢与国内增加值之间的动态联系。最后,探讨了产业关联外溢问题对产业体系内生形成的启示。     

航空运输、知识空间溢出与城市创新能力——来自19个大城市的证据

基于2003—2018年19个大城市数据,设置空间地理权重矩阵计算Moran′s I指数和Geary′s C指数检验城市创新产出的空间自相关,借助stata软件构建并选择时空双固定效应的空间面板杜宾模型.实证性研究发现航空运输能够压缩城市时空距离,加快人才流动中所产生的知识空间溢出,促进城市创新能力;进一步研究表明,发展航空运输与现代通信技术对于城市创新能力的影响呈互补关系;航空运输通过增强知识精英与研发资金、教育活动投入等创新要素之间的相互作用,从而促进城市的创新能力,并且也对周边城市的创新能力起到积极作用.     

我国丝绸之路经济带物流设施效率分析--基于DEA 模型的M almqusit指数方法

“道路联通”既是实现丝绸之路经济带“贸易畅通”的基础保障,也是实现“民心相通”、“货币流通”和“政策沟通”并最终实现区域经济一体化和社会文化融合的助推器。采用DEA模型的M almqusit指数分析法对我国丝绸之路经济带物流设施效率进行了分析。分析得出结论：贸易环境负向变化是造成我国丝绸之路经济带交通基础设施效率下降的主要原因;提高经济带物流设施对经济的贡献不应只关注新增交通基础设施,更应关注现有物流设施的运营效率;为提高经济带交通基础设施的整体效率,今后交通基础设施建设的区域结构应倾向于陕西、江苏、山西、安徽等仍存在物流设施规模效率的省份。     

Effects of Transport Regulation on the Oil Market: Does Market Power Matter?

Instruments used to regulate the consumption of oil in the transport sector include fuel taxes, biofuel requirements, and fuel‐efficiency standards. However, the effects that these have on oil consumption and price vary. If market power is present in the oil market, the directions of change in consumption and price might contrast with those in a competitive market. As a result, the market structure affects not only the effectiveness of the policy instruments used to reduce oil consumption, but also the terms of trade and carbon leakage. In particular, reduced oil consumption, as a result of increased fuel‐efficiency standards, will unambiguously increase the price of oil under a monopoly.     

An utility-based decision support sustainability model in slow steaming maritime operations

This paper analyses slow steaming sustainability initiatives and generalizes the traditional discrete cost-based decision support model into novel continuous utility-based models. Two models based on logarithmic and linear utility functions are developed for risk-averse and risk-neutral decision makers respectively. The models, considering fuel consumption, carbon emission, and on time delivery, are applied to a Trans-pacific trade service route. A sensitivity analysis is conducted on parameters of sailing distance, expected transit time, quantity, and emission policies. The model contributes to ship liners on the optimal speed decisions in continuous utility-based slow steaming operations.     

大力发展集装箱海铁联运 推动上海国际航运中心建设——以洋山港、芦潮港为例

集装箱集疏运体系结构不合理、公路比例偏高已成为制约上海国际航运中心可持续发展的因素,无论是从环境保护、节能减排的客观要求出发,还是从上海国际航运中心可持续发展的主观能动性出发,都要求集疏运体系由公路向水路与铁路转移,优化集疏运体系结构,实现上海国际航运中心的可持续发展。     

Endogenous Transport Coefficients: Implications for Improving Water Quality from Multi-Contaminants in an Agricultural Watershed

The effectiveness of imperfect pollution control instruments is examined for a diffuse source, multi-contaminant problem in which the transport coefficients for sediment-bound residuals are endogenous. Similar evaluations fix the percentage of sediment deposited and optimize either for a single firm managing the whole watershed or on a firm by firm basis. This study shows that ignoring the dependence of the transport coefficients on intervening land uses creates a positive externality. The filtering potential of activities conducted by firms close to the receptor permits firms further away to undertake more profitable but erosive practices. Optimizing management choices, and consequently endogenizing the transport coefficients, for all firms simultaneously removes the externality. An empirical application combines hydrological simulation models with an economic optimization model for nutrient pollution of surface and ground water within an agricultural watershed. Although firms are homogeneous in abatement costs, differences in spatial location leave uniform instruments unable to achieve the water quality goal efficiently. An ambient tax/subsidy scheme can achieve the water quality goal efficiently but the informational requirements will be excessive in most situations where the transport mechanisms for residuals are dependent upon the practices of independent decision making units.     

上海转口贸易对近代中国贸易市场的影响

近代上海的开埠带来了国内市场的变化。19世纪60年代后,中国沿海与长江各口岸相继对外开放,沿海沿江贸易航运业快速发展,形成埠际贸易网络。上海转口贸易通过埠际转运网络的各级市场影响中国长江流域和华北、东北、西南、华南地区。在此过程中,上海与近代中国其他重要的通商口岸之间形成了固定的埠际转运网络,上海埠际贸易网络日益呈现出结构化特征。     

Dynamic cost functions and freight transport modal split evolution

The paper studies the characteristics of the evolution over time of modal split for a transport system in which various modes compete with each other and face the freight flow increase in different ways. It is shown that the modal split evolution is constituted by a sequence of time periods, in each of which the dynamic characteristics of the system are different. An equilibrium, stable or unstable, is reached after a transition phase, whose length depends on the characteristics of the system, and in some cases exceeds the length of the period, so that an equilibrium is not reached.