世界港口管理体系剖析

全面展示了全球主要港口管理体系现状．通过对世界各国港口管理体制改革的研究,对改制后的几种港口管理模式进行了比较分析,并指出港口管理结构重组的主要任务是通过实施“解除管制”措施以及推动商业化、企业化和民营化进程来限制政府的干预范围,吸引私方资本．尤其对世界港口管理体制改革过程中存在的局限性进行了探索和分析,并提出了相应的解决对策、最后得出：港口体制改革机构在实施改革之前,应根据各国港口发展环境的具体情况,考虑采取一系列相应的有效配套措施,以便改制后的港口能更好地适应市场竞争和经济全球化需求．     

指令驱动市场中的组合下单策略研究

已有研究一般直接假设指令驱动市场中的知情交易者总是选择市价单进行交易，本文则基于现实交易状况．建立了一个理论模型．分析拥有私有信息的知情交易者组合使用限价委托单和市价委托单的决策问题．具体给出了不同私有信息状态下知情交易者的组合下单选择。     

Comments on purification in continuum games

It is pointed out that Corollary 1 in a recent paper by Khan et al. (Int J Game Theory 34:91–104, 2006), presented there as an extension of the Dvoretzky–Wald–Wolfowitz theorem, is a special case of Lyapunov’s theorem for Young measures (Balder in Rend Instit Mat Univ Trieste 31 Suppl. 1:1–69) It is also pointed out that Theorems 1–4 in Khan et al. (Int J Game Theory 34:91–104, 2006) follow from a single strong purification per se result that is already contained, as an implementation of that Lyapunov theorem for Young measures, in the proof of Theorem 2.2.1 in Balder (J Econ Theory 102:437–470, 2002).     

A New Fluorimetric Reagent for Determination of Trace Amounts of Europium

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基于层次分析法的几种家用汽车购车模型

目前,随着我国人民生活水平的不断提高,家庭购车逐渐成为一种新的需求.但面对纷繁多变的汽车市场,很多消费者苦于车型的抉择.为了解决家庭购车中的科学决策问题,根据来自汽车销售市场的实际信息,以目前几种10万元以下的主流家用轿车为研究对象,应用层次分析法得到购买家用汽车的数学模型,从而使定量化地解决了车型抉择问题.     

Private equity firm experience and buyout vendor source: What is their impact on efficiency?

Using a dataset comprising 88 Private Equity (PE) backed Leveraged Buyouts (LBOs) completed and exited during the period 1999–2008, this study sheds new light on the impact of buyout vendor source and PE investor experience on post-buyout efficiency during the first 3 years after the transaction. There are three main findings. First, we observe increases in post-buyout efficiency over time, although LBOs from different vendor source differ in terms of post-transaction efficiency levels and improvement trajectories. Private and divisional buyouts are more efficient than the average. Divisional buyouts show higher efficiency improvements than private and secondary buyouts. Secondary buyouts remain below the average. Second, multivariate analyses suggest a positive and significant effect of PE firm experience on post-buyout efficiency. Finally, the observed efficiency patterns seem to be convex, suggesting the major improvements happen in the first 2 years after the transaction.     

Non-lane-based full velocity difference car following model

In order to describe car following behavior in real world, this paper presents a non-lane-based car following model by incorporating the effects of the lane width in traffic. The stability condition of the model is obtained by using the linear stability theory. And numerical simulation is carried out to validate the analytic results. The property of the model is investigated, and it is found that the proposed model can describe the phase transition of traffic flow and estimate the evolution of traffic congestion. The results implied that incorporating the lane width effects in car following model not only stabilize traffic flow and suppress the traffic jam, but also lower critical headway and increase capacity. Thus, the lateral separation effects greatly enhance the realism of car following models.     

Solving a multi periodic stochastic model of the rail–car fleet sizing by two-stage optimization formulation

We propose a formulation and solution procedure for optimizing the fleet size and freight car allocation under uncertainty demands. There are important interactions between decisions on sizing a rail–car fleet and utilizing that fleet. Consequently, the optimum use of empty rail–cars for demands response in the length of the time periods one of advantages the proposed model. The model also provides rail network information such as yard capacity, unmet demands, and number of loaded and empty rail–car at any given time and location. Consequently, the model helping managers or decision makers of any train company for planning and decision making. We propose two-stage solution procedure for solve rail–car fleet sizing problem. Numerical examples are given to illustrate the model and solution methodology.     

基于轮轨蠕滑机理的货车车轮磨耗寿命预测

为对货车车轮磨耗寿命进行预测,在SIMPACK中建立车辆-轨道多体动力学模型,基于轮轨半赫兹接触理论和Zobory车轮磨耗模型编制车轮磨耗数值仿真程序.对C80型货车等在环形线和大秦线上运行时的车轮磨耗行为进行仿真,并根据实测结果和仿真结果对Zobory车轮磨耗模型进行修正,最后利用修正后的Zobory模型对C80型货车在国内某重载线路上运行时的车轮磨耗寿命进行预测.结果表明:车辆在环形线和大秦线上运行时,仿真得到的车轮磨耗分布范围以及圆周磨耗深度和轮缘厚度随运行里程的变化趋势均与现场实测结果较为接近,但车轮圆周磨耗率分别为实测结果的1.394 ～1.842倍和2.172 ～3.658倍,主要原因是仿真中采用了轮轨半赫兹接触理论,考虑了弹性剪切变形对滑动速度的影响,并且国内货车采用的CL60钢的硬度大于国外BSll钢的硬度;C80型货车在国内某重载线路上运行时,利用修正后的Zobory模型仿真得到的车轮段修磨耗寿命为39×105 km,运用磨耗寿命为65×105 km,与现场统计结果较为吻合.     

隐私性疾病诊疗社会乱象分析及对策研究

针对目前社会上存在的隐私性疾病诊疗乱象,采用调研暗访法、案例分析法、问卷调查法等研究方法,总结分析了民营医院乱收费、医疗水平低下、过度治疗等诊疗乱象的现状和形成原因,探讨了监管部门、民营医院、患者和公立医院在诊疗乱象中的作用,得出以下结论:监管力度不够、民营医院以盈利为目的、患者维权意识淡薄共同导致了隐私性疾病诊疗乱象的出现.为了消除诊疗乱象,应从治疗效果差异、隐私性疾病科普、打击非法医疗机构和构建良好医患关系等方面进行应对.