区域运输结构的自组织演化机制研究——基于logistic模型的分析

运输结构是指各种运输方式在运输过程形成的功能构成和资源配置。本文尝试运用自组织理论的原理和方法,探讨了区域综合运输体系结构变化的影响因素和自组织机制,应用涌现原理、反馈原理、涨落原理和环境选择原理分析运输系统结构演化的过程,建立了运输结构自组织演化的Logistic模型,并结合湖北省沿江经济带的案例,对区域货物运输结构演化的过程和趋势以及各种运输方式之间的相互影响关系进行了分析,同时提出了自组织理论对区域运输体系建设发展的启示。     

Estimating visitors’ travel mode choices along the Bear Lake Road in Rocky Mountain National Park

The National Park Service (NPS) in the United States of America (USA) is looking to alternative transportation systems to provide visitors access to the national parks in a manner that potentially reduces traffic congestion, enhances visitors’ experiences, and more effectively protects park resources. However, shuttle bus systems without adequate planning and management may lead to unintended consequences such as eliminating the constraint to visitor use levels associated with parking lot capacities. As a consequence, the demand for recreation use in the area increases the potential impacts to the visitor experience and park resources. This study examined the trade-offs Rocky Mountain National Park visitors were willing to make about transportation mode choice using a stated choice survey to inform park managers about visitor acceptance of potential transportation related management actions. Results indicate that visitors prefer to use their private vehicles over the parks transit system but are willing to make trade-offs to ride the shuttle bus in order to avoid crowding along the trail at Bear Lake and vehicle traffic along the Bear Lake Road. In addition, there were statistically significant differences among choices of transportation mode trade-offs among different age groups (i.e., less than 40 years of age, 40–60 years of age, and more than 60 years of age) Specifically, results suggest that visitors less than 40 years are more willing than the older age groups to make trade-offs among transportation options to enhance their chances of being on the trail system at Bear Lake with fewer other people. The significant and interacted relationships with shuttle bus use, visitor use, and vehicle traffic levels found in this study provide RMNP managers opportunities to influence visitors’ transportation mode choices.     

IS POOLING LEAD‐TIME RISK BY SPLITTING ORDERS SIMULTANEOUSLY WORTHWHILE?

A large body of research is based on the proposition that pooling lead‐time risk by splitting orders simultaneously can offer significant opportunities to reduce inventory system costs. This paper investigates that proposition for a broad range of industry conditions, as well as for a high‐tech company in a global setting. The investigation considers important cost elements not included in previous work to conduct a realistic assessment of the value proposition. The results indicate that, even under favorable conditions, the proposition is worthwhile only when lead‐time variability and unit values are unusually high. Managerial implications and new research directions are discussed in light of these findings.     

Optimisation of the exploitation period of individual vehicles in freight transportation companies

The individual vehicle replacement problem typical for freight transportation companies is discussed in the paper. Two characteristic features of such problem are that transportation companies utilise vehicles with intensity decreasing with an age of vehicles and that managers of such companies first of all take into account economical criteria when planning vehicle replacements. The paper presents a single criterion, nonlinear, deterministic and discrete mathematical model of such a problem that minimises a total exploitation and ownership costs calculated per kilometre. The exact solution procedure is proposed here. The problem is solved as a real life case study. As a result, an average, economically optimal 5-year exploitation period of vehicles has been determined.     

A hybrid implementation mechanism of tradable network permits system which obviates path enumeration: An auction mechanism with day-to-day capacity control

Akamatsu, 2007a, Akamatsu, 2007b proposed a new dynamic traffic congestion control scheme called tradable network permits, and demonstrated its efficiency properties for general road networks. To implement tradable permit markets, this paper proposes a novel auction mechanism with capacity control. This mechanism employs an evolutionary approach to achieve a dynamic system optimal allocation of network permits in a computationally efficient manner. We prove that the proposed mechanism has the following desirable properties: (i) truthful bidding is a dominant strategy for each user on each day and (ii) the permit allocation pattern under the mechanism converges to a dynamic system optimal allocation pattern.     

基于物流人才能力需求的《运输经济学》课程建设研究

以《运输经济学》为例,分析了物流管理专业核心课程基于案例教学的课程建设新途径,并介绍了基于案例教学的《运输经济学》课程创新教学方法与内容。     

基于工作过程的高职院校校企合作办学培养模式的探讨

我国现阶段高职院校所开展的校企合作大多流于形式、浮于表面。如何选择恰当的人才培养模式,与企业深度有效合作?如何培养出符合企业要求的高素质技能型人才?如何突破浅层次、表面化校企合作的瓶颈,成为现今高职教育面临的首要问题。文章以重庆交通职业学院开展基于工作过程的校企合作人才培养模式为例,阐述了该院在建立整合企业资源,发挥学校教研优势的管理机制方面的新探索,并提出其中的不足,希望探索出真正能够实现资源互补,达到"校、企、生"三赢的职业教育目标的人才培养模式。     

Coordinated aviation network resource allocation under uncertainty

Congestion in the air traffic system, both recurrent and non-recurrent, is typically handled by rationing access rights to individual resources such as airports or important parts of the airspace. Under the planning paradigm employed in the US, this rationing process occurs independently at each resource. The stochastic integer programming model proposed in this paper brings coordination to this process while considering capacity uncertainty. Results of a case study suggest that the model is tractable, and generates capacity allocations that improve efficiency and enable greater responsiveness to changing capacity conditions.     

Dynamics and equilibria of ecological predator-prey networks as nature’s supply chains

In this paper, we develop a dynamic network model of ecological food webs and prove that the set of stationary points of the projected dynamical system coincides with the set of solutions of a variational inequality governing the equilibrium of predator-prey networks. We also establish the equivalence between the ecological models and supply chain network equilibrium models and highlight the connections to spatial price equilibrium problems. We propose an algorithmic scheme, provide convergence results, and apply it to a food web drawn from a fisheries application.This paper is a contribution to the interdisciplinary supply chain network literature.     

The origins,development and future directions of data envelopment analysis approach in transportation systems

Over the last two decades, application of Data envelopment analysis (DEA) in transportation problems have gained considerable research attention. This paper presents a literature review and classification of the applications of DEA in transportation systems (TSs). First by classifying 40 papers from 2007 to 2018, the origins of DEA in transportation problems have been reviewed. Then the development and an overall view of DEA applications in TSs have been presented. We have classified the applications of DEA into six different contexts. In each context, published papers have deeply been analyzed. Content of analysis includes “Number of published papers during the time”, “target journals”, “countries”, “keyword frequency”, “most cited papers”, “map of most co-cited publications”. More important, we reported the “inputs and outputs variables” used in each paper. Further “a review of the selected papers” and “gaps/future research directions” have been given within each cluster. The results show that DEA is one of the most useful approach in evaluating TSs for policy makers. On the other hand, DEA can help the decision makers in transportation especially regarding environmental factors, sustainable development and eco-design. Finally, we proposed subjects for future researches including guidance for new studies in the field of DEA applications in TSs.