城市公共交通多元票制初探

借鉴国外先进经验,引进多元化公交票制是国内推进公交优先发展的重要措施.多元票制,即将乘客进行科学的分类,根据乘客的出行需求,设置不同种类的车票,以提高公交吸引力.就国内公交发展现状来看,换乘优惠的票制改革是推广多元票制的最佳切入点.     

Improved Urban Inhabitant Travel Demand Model and Its Application

Transport planners often need to forecast the influence of the transport policies on travel demand, e.g., construction of a new transport alternative, changing public transit fares, or imposing road pricing schemes. Stated preference (SP) surveys are frequently adopted by transport planners for the analysis of the impact of transport policies on travel demand. However, evidence suggests that preferences derived from SP surveys are contingent on context, which indicates that trip makers may show asymmetric preferences for different levels of services. The objective of this article is to propose an alternative conceptual framework for travel demand analysis. It is expected that travel behavior may be heterogeneous across trip makers; response (or parameter of) to the level of service is defined as a function of the attributes of the trip makers. It is also aimed to propose some urban transportation policies based on a new type of discrete choice model. In an empirical demonstration, the panel data obtained from commuters in Lanzhou, China, are used, and support is obtained for several predictions on why behavioral intentions are, or are not, implemented.     

投资者风险投资行为选择

为更好地指导投资者,从行为金融学的角度,通过对投资者的风险规避效用曲线、期望效用、投资净现值和投资机会成本的分析,探讨了投资者风险态度的界定、阶段性投资工具配置、投资决策中机会成本的把握和投资期权的运用等影响投资者风险投资行为选择的因素.研究表明:投资者的风险偏好直接影响其对风险性收益的追求,并反映了投资者承受风险的心理临界;随着风险企业的发展,投资者以股权、债权的投资分别有减少、增加的趋势;在风险企业(项目)单位产出价格不变的前提下,投资者保持还是行使期权执行权力,取决于投资机会成本与净投资收益比较的高低;反之,投资等待还是加大投资的趋向将随单位产出价格的降低或提高而增强.     

A study of carpooling behaviour using a stated preference web survey in selected cities of India

This paper analyses how people perceive the idea of carpooling and evaluate preferences while making a decision to join a carpool. Analysing data from a web-based stated preference survey in India reveals that cognitive attitudes play a significant role in evaluating the perceived advantages and disadvantages of carpooling whereas intentions to carpool are associated with perceived negative evaluations. A factor analysis identifies two latent attitudinal factors: a ‘time–convenience’ factor that discourages carpooling and a ‘private–public cost’ factor that encourages carpooling. The study analyses the influential attributes – extra travel time, walking time to reach meeting point, waiting time at pickup point and cost savings – as explanatory variables for the utility of carpooling. Cost savings prove to be the most significant attribute when combined with other attributes, followed by extra travel time. The study provides the implications to policy-makers of designing promotional tools to improve the propensity of carpooling among single occupant vehicle drivers.     

基于交互式多目标遗传算法的混凝土桥面板维修优化

为了保证桥梁结构安全,并使维修效果最好,研究了如何确定桥面板最佳维修策略的问题。建立了桥面板维修的多目标优化模型。提出一种基于交互式遗传算法的维修策略优化方法,通过非精确偏好信息引导遗传搜索,使种群朝着多个目标的最佳综合性能进化。引入适应值共享方法增加种群的多样性,最终获得符合决策者偏好的解集。并通过算例进行了分析验证。结果表明,基于交互式多目标遗传算法的混凝土桥面板维修优化方法可以在有限的桥梁维修资源和良好的维修效果之间进行折衷,不仅获得一组比较理想的维修方法组合,还可以考虑决策者的个人倾向,降低了维修策略的选择难度,为桥梁管理者提供了有力的决策支持。     

基于决策场理论的出行者动态决策行为研究

为了研究出行者进行路径选择时的动态决策过程,本文采用决策场理论,研究 了多属性条件下,机动车出行者的微观和宏观动态决策行为.分析了决策场理论的基本模 型,构建了出行者动态决策行为场景和框架,以历史出行时间、预测出行时间和两者综合 值作为出行者决策的路径属性,并根据属性与实际出行时间的差值为依据,提出了出行 者注意力权重矩阵计算方法.通过算例分析发现,自由流出行时间对出行者决策影响较 大,出行者对路径属性的依赖性非常强,决策过程中存在路径偏好反转的现象,表明出行 者动态决策过程是随时间不断变化的,路径选择是时间累计的结果.     

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优先发展公共交通,提高公交运行效率,不仅是缓解城市交通拥堵的有效措施,也是调整城市交通出行结构、改善城市人居环境、促进城市可持续发展的必然要求. 为制定科学、合理的公交票价政策,引导大众选择公共交通方式出行,以成都市为背景,采用问卷调查方法对不同出行者、不同票制、不同票价、不同换乘费用进行意愿调查,得到最大满意度票价;基于调查数据,进行供求曲线分析,提出以最适票价满意度作为供求平衡点;通过票价意愿曲线,进行客流、票价间敏感性分析,得到不同出行者票价梯度变化规律. 本研究可为公交分担率提升,合理票制票价的制定提供依据.     

高铁开通后对走廊内公路运输的影响

分析高铁和高速走廊出行者特征及交通流特征,可以为制定合理的高铁及高速班车票价、高速公路收费,构建各方式互补、结构合理的城市间出行市场提供依据,为中国其他将要建设高铁或准备提高高铁服务品质的城市提供参考。     

基于旅客出行意图的航线潜在价值计算模型

传统的航线价值计算通常以统计客流量为主,忽略了旅客偏好对航线潜在价值的影响,因此,本文提出了一种基于旅客出行意图的航线潜在价值计算模型.该模型利用最大似然估计法对旅客舱位偏好进行量化,然后引入出行意图的概念将旅客出行行为进行细分,并利用Gibbs Sampling方法实现出行意图的求解,最终达到航线潜在价值计算的目的.在中国民航旅客订票数据集上的实验表明,本文方法获得的2010年航线价值序列与2011年航线价值序列的相似度要明显高于统计客流量的方法,且对排名前5的高价值航线的挖掘准确率可达100%.     

Effect of risk preference on the valuation of time charter contracts with extension options

ABSTRACT

The literature on valuation of time charter contracts and real options in shipping generally relies on the complete markets hypothesis and the risk-neutrality of agents. However, these assumptions fail completely in some shipping market segments. This study proposes a numerical approach—based on discounting the certainty equivalent payoff at the risk-free rate—which incorporates the agent’s risk preferences through an exponential utility function. The method comprises an iterative Monte Carlo nested simulation with the real probability measure. This method is applied to a case of Suezmax tankers. The stochastic evolution of the time charter rates is modelled as a geometric mean-reverting process. The case study supports the applicability of the proposed method and evidences that the effect of risk preference may be significant, mainly for more risk-averse agents. Although the method involves intensive computation, it has the benefits of theoretical ease and flexibility, which could encourage utilisation by practitioners.