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We investigate second-hand vessel price heterogeneity. Based on a sample of 5,591 purchase and sale transactions in the dry bulk sector over the period 1998–2016, we deploy a nonparametric regression technique to assess the determinants of vessel price and vessel price variability. Next, we use quantile regression to estimate the effect of regressors (sources of heterogeneity) at different parts of the vessel price distribution. We find evidence that main sources of vessel price heterogeneity are the age of the ship (the older the vessel the higher its maintenance cost), the 3-month LIBOR (reflecting the cost of financing) and the annual charter rate (revenues from operation). Their influence is stronger at all higher quantiles (periods of expansion) and the median of the vessel price distribution. 相似文献
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南安普敦市高速公路入口控制方案案例研究 总被引:1,自引:0,他引:1
高速公路入口控制最早于1996年出现在芝加哥市,现在北美及欧洲等国家广泛采用它来缓解高速公路交通拥挤状况。此论文研究了南安普敦市高速公路入口控制方案的案例(采用ALINEA)控制策略。研究的详细数据表明:高速公路入口控制系统对辅路上的车流、高速公路主干线上的车流、尤其是对高速公路第一车道入口汇合前的区域存在潜在影响。基于此案例研制高速公路的主干道的车流量和速度的轻微减小。 相似文献
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本文译自美国《MOTOR》杂志,作者深入浅出地全面讲解汽油直接喷射技术,生动地对这一技术产生的背景、结构原理、主要组成部件以及未来发展趋势进行了系统的阐述。 相似文献
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Mark Brownrigg Geoff Dawe Mike Mann Phillip Weston 《Maritime Policy and Management》2013,40(3):213-223
The new UK Government, elected in May 1997, came to power with a commitment to reverse the decline of the UK shipping industry and enhance the employment prospects of UK seafarers. The Government commissioned Lord Alexander of Weedon to investigate the case for a tonnage tax. In this paper, the economic arguments for supporting the UK shipping industry are reviewed. There is some evidence that the UK holds a comparative advantage in world markets in key sectors of the shipping industry and on-shore maritime related activities, but is being undermined by lower foreign taxes. In the absence of government support, the UK shipping industry is likely to continue to decline, and, by further reducing the supply of qualified UK ex-seafarers, put at risk the successful on-shore activities. Various measures that might be used to support a national shipping industry, e.g. a tonnage tax, are considered. The paper concludes by discussing the likely impact of the tonnage tax on the UK's shipping industry. 相似文献
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一种功率更大、尾气排放更少和燃油经济性更佳的发动机即将问世,而这种发动机与现在的发动机相比不仅在内部结构上进行了改进,尤其在电子技术方面有了更大的提局。 相似文献
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目的 了解心脏前负荷减低对中心动脉压及主动脉扩增指数的影响.方法 10例健康志愿者,行下肢负压(LBNP)抽吸造成不同程度前负荷减低.采用超声心动图检测心输出量的变化;采用中心动脉压力分析系统(SphymoCor)检测桡动脉压力波形,经平均转换功能形成中心动脉压力波形.结果 ①随着下肢负压的加大,上腔静脉血流进行性减低,在-30mmHg阶段,S波减低22.4%,VTIs+d减低了15.8%,同时SV减少24.7%,CO减少18.7%;②中心动脉收缩压(CSBP)除在-30mmHg阶段轻度下降外,在-10及-20mmHg阶段没有明显改变,中心动脉舒张压(CDBP)在各个负压阶段没有明显改变;③主动脉压力波P1在各个负压阶段均明显下降,在-30mmHg阶段,P1减少了19.6%[(28.2±5.02)mmHg vs.(22.65±3.08)mmHg, P<0.01],而总外周阻力(TPR)在各负压阶段均较基础阶段明显升高,在-30mmHg阶段升高21.3%[(16.0±2.9)(mmHg·min)/L vs.(20.3±3.4)(mmHg·min)/L, P<0.001].主动脉扩增指数(AI)无明显改变.结论 前负荷减低使中心主动脉压及主动脉压力波P1降低,同时使TPR升高,由于TPR的升高抵消了P1 的降低,因而AI保持不变. 相似文献
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Mike Knutton 《轨道交通》2007,(5):72-73
韩国正在建设的机场高速线是一条全长61.7公里,连接首都首尔和仁川国际机场。2001年3月重新改组合并的仁川国际机场铁路公司(Iiarco)获得了该高速铁路30年的运营许可。目前该铁路已经有部分投入使用。文章从规划、实施和运作等方面来对该快速线作了详细介绍。 相似文献
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Transportation - Coupling activity-based models with dynamic traffic assignment appears to form a promising approach to investigating travel demand. However, such an integrated framework is... 相似文献
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<正>可以说,过去数年对汽车供应商而言是非常具有挑战的时期。在去年的金融危机中,几乎所有供应商,或小或大都受到了严重的打击。有些幸运的公司或许能 相似文献