综合管廊投资运营模式选择模型构建研究

为从当前国内常用的投资运营模式中遴选出与综合管廊项目特征契合的模式,保障综合管廊实现成功运营,通过对国内常用的几种投资运营模式进行分析,建立以项目特征、工作效能、社会效益、经济效益和项目风险为准则层、包含18个指标的综合管廊投资运营模式选择指标体系,选择逼近理想解对指标进行量化计算。运用层次分析法与逼近理想解相结合的方法克服逼近理想解无法确定指标权重的缺点,并引入云模型对层次分析法和逼近理想解分别加以改进,充分考虑模式选择过程中专家评价语言的不确定性,构建基于云模型改进AHP-TOPSIS的综合管廊投资运营模式选择模型,同时以西安市某综合管廊PPP项目Ⅰ标段为案例,验证了该模式选择模型具有较高的拟合度。     

A constraint programming model with time uncertainty for cooperative flight departures

The lack of a proper integration of strategic Air Traffic Management decision support tools with tactical Air Traffic Control interventions usually generates a negative impact on the Reference Business Trajectory adherence, and in consequence affects the potential of the Trajectory-Based Operations framework. In this paper, a new mechanism relaying on Reference Business Trajectories as a source of data to reduce the amount of Air Traffic Controller interventions at the tactical level while preserving Air Traffic Flow Management planned operations is presented. Artificial Intelligence can enable Constraint Programming as it is a powerful paradigm for solving complex, combinatorial search problems. The proposed methodology takes advantage of Constraint Programming and fosters adherence of Airspace User’s trajectory preferences by identifying tight interdependencies between trajectories and introducing a new mechanism to improve the aircraft separation at concurrence events considering time uncertainty. The underlying philosophy is to capitalize present degrees of freedom between layered Air Traffic Management planning tools, when sequencing departures at the airports by considering the benefits of small time stamp changes in the assigned Calculated Take-Off Time departures and to enhance Trajectory-Based Operations concepts.     

Port competition with accessibility and congestion: a theoretical framework and literature review on empirical studies

This review interprets recent studies of the interactions between the competition of gateway seaports and the accessibility of landside transportation links to inland regions. Port competition is treated as part of a rivalry between two transportation chains. This article identifies the main modeling approaches and defines the different types of hinterland access systems described in the literature. A general theoretical framework is then proposed to incorporate those key components. The importance of the proposed framework is revealed by comparing and extending results from the literature. Major assumptions that need further empirical verification are identified and discussed, and related empirical studies are reviewed. Finally, avenues for further research are discussed.     

Internalization of port congestion: strategic effect behind shipping line delays and implications for terminal charges and investment

This paper develops a theoretical model to analyze the congestion internalization of the shipping lines, taking into account the ‘knock on’ effect (i.e. the congestion delay passed on from one port-of-call to the next port-of-call). We find that with the presence of the knock-on effect, liners will operate less in terminals, and an increase of a liner’s operation in one terminal will decrease its operation in the other. If the liners are involved in a Stackelberg competition, whether they operate more or less in a terminal under the knock-on effect depends on the comparison between the marginal congestion costs of terminals. Furthermore, we find that the coordinated profit-maximizing terminal charges are higher than both the socially optimal terminal charges and the independent profit-maximizing terminal charges. When the knock-on effect is small, the independent profit-maximizing terminal charges are set at higher levels than the socially optimal terminal charges; but when the knock-on effect is sufficiently large, this relationship may reverse. Besides, the capacity investment rules are the same for welfare-maximizing terminal operator and coordinated profit-maximizing terminal operator, while independent profit-maximizing terminal operators invest less in capacity. The larger the knock-on effect, the larger this discrepancy.     

基于土地开发收益的轨道交通间接利益还原模式研究

分析了目前我国城市轨道交通的投资和运营资本的来源和现状,结合廊道效应阐述了轨道交通对沿线区域土地不动产带来的利益及利益分配的不合理性。按照轨道交通对城市的功能作用,可分为引领城市的合理发展而建设的轨道交通和解决城市交通拥挤问题而建设的轨道交通两种情况,并分别讨论了间接利益的还原方式和指出要保证间接利益还原的合理性。     

公路客运站场体系投资分配方法

为合理划分公路客运站场体系中不同建设主体的投资份额,对公路客运站场体系的层级结构及其地方性准公共产品特征进行分析,并根据“受益原则”将公路客运站场的受益群体分为全国性、区域性与地区性客流三个层次,由此可建立基于受益群体构成的公路客运站场投资分配模型。实例表明,基于受益群体构成的公路客运站投资分配方法可行,规划方案可操作性强。     

港口建设对区域经济技术效率的影响研究

沿海港口建设作为基础设施领域的重要投资,对区域经济发展起着直接和间接的作用.为了考察港口建设与区域经济技术效率之间的关系,本文采用随机前沿分析方法,将港口建设投资作为模型中技术无效项的核心解释变量,通过实证分析表明,我国沿海港口建设投资对区域经济技术效率的提升具有显著的正向作用,而且不同时段、不同地区的港口建设对区域经济技术效率的影响存在明显差别.在港口建设规划与政策制定过程中,应将区域经济技术效率因素和不同港口群之间的发展差异特征考虑在内.     

全寿命视角下的公共停车场PPP项目成本效益分析

为了保障政府和社会资本合作（Public-Private Partnership, PPP）的公共停车场项目合理的成本效益,应用全寿命周期理论,系统梳理了其成本效益组成结构及影响因素,建立了不同PPP模式下不同建筑形式的停车场（地下停车场、停车楼和机械式停车场）固定成本模型、年运营收入与费用模型和基于动态投资回收期的成本效益分析模型;探讨用地、停车收费及金融政策对不同PPP模式、不同建筑形式公共停车场动态投资回收期的影响,并以居住类公共停车场为例开展案例分析。结果表明：当内部收益率和收费价格一定时,对于机械式停车场和地下停车场,TBT（Transfer-Build-Transfer）模式动态投资回收期最短,其次为BOT（Build-Operate-Transfer）模式和BOO （Build-Own-Operate）模式;对于停车楼,BOT模式动态投资回收期最短,其次为TBT模式和BOO模式;当附属商业面积比例为20%时,不同建筑形式的居住类公共停车场动态投资回收期均小于15年,满足社会资本目标;土地价格一定时,增加附属商业面积比例可以使动态投资回收期缩短0.4~10年;转让停车场规模为小型或中型时,转让车位价格小于21.21万元,社会资本均可在15年内收回成本。     

新冠肺炎疫情对交通基础设施投融资的影响及应对策略

当前我国正处于深化供给侧结构性改革,推进经济转型升级和高质量发展的关键时期。突如其来的新冠肺炎疫情,给我国正常的经济发展和社会生活造成了冲击,加大了不确定性和经济增长压力。为此,采用文献资料收集和统计分析等方法,深入分析本次疫情对交通投融资产生的影响。首先回顾并量化分析了“非典”疫情和美国次贷危机等重大事件下,交通投融资具有的受冲击大、波动性明显、地位作用突出、效用缓释等特征,然后剖析了新冠肺炎疫情对交通投融资活动的具体影响,最后结合当前中央和地方开展的积极应对举措,从完善顶层设计、稳定并拓宽融资渠道、积极争取财税金融扶持、优化前期工作等方面,提出了交通基础设施投融资应对新冠肺炎疫情的具体措施建议。     

新时期城市轨道交通发展的思考

我国城市轨道交通已进入了快速发展时期,但在轨道交通的规划建设中,还存在着一系列需要认真研究的问题,诸如轨道交通在城市中的定位及其与城市的相互作用关系,轨道交通的经济属性,建设、运营和投融资体制以及法制和标准化建设等。明确轨道交通在城市中的定位,理顺其与城市间的相互作用关系,正确认识轨道交通的经济属性,建立适应轨道交通发展的建设、运营和投融资体制,完善法律法规体系和标准化工作,是保障我国城市轨道交通健康发展的基础。