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排序方式: 共有369条查询结果,搜索用时 15 毫秒
51.
旨在研究具有组合复合实物期权特征的船舶投资决策。通过建立二叉树定价模型,并利用Crystal Ball软件运用蒙特卡洛模拟方法模拟航运市场波动率,从而对船舶投资项目进行评价。通过实例分析得出,拥有多重选择性的船舶投资项目的价值要大于仅有单一期权的投资项目价值。  相似文献   
52.
结合高速公路项目选线的特点,采用层次分析法、模糊综合评价理论等系统分析方法,对高速公路线路方案的选择进行探讨。针对高速公路方案选择既有模糊性又有相对性的特点,建立高速公路选线方案决策系统模糊优化理论模型。  相似文献   
53.
随着我国城市化水平的不断提高,城市轨道交通与房地产的关系越来越紧密。城市轨道交通与房地产开发相互关联、相互影响,两者的协调发展能够促进城市的健康、有序发展。然而,在现实中两者之间经常表现为不协调发展状态,这将影响到城市居民的生活方便度和社会经济的可持续发展。研究以武汉市为例,采用熵值法,建立起城市轨道交通与房地产开发的协调发展评价体系,研究城市轨道交通与房地产开发的协调发展水平,以期促进二者的协调发展。研究发现:武汉市城市轨道交通与房地产开发协调程度总体上呈现出不协调发展的态势,房地产开发超前于城市轨道交通,但随着经济的发展两者趋向协调并稳步向前发展。  相似文献   
54.
Traction control is a very important aspect in railway vehicle dynamics. Its optimisation allows improvement of the performance of a locomotive by working close to the limit of adhesion. On the other hand, in case the adhesion limit is surpassed, the wheels are subjected to heavy wear and there is also a big risk that vibrations in the traction occur. Similar considerations can be made in the case of braking. The development and optimisation of a traction/braking control algorithm is a complex activity, because it is usually performed on a real vehicle on the track, where many uncertainties are present due to environmental conditions and vehicle characteristics. This work shows the use of a scaled roller rig to develop and optimise a traction control algorithm on a single wheelset. Measurements performed on the wheelset are used to estimate the optimal adhesion forces by means of a wheel/rail contact algorithm executed in real time. This allows application of the optimal adhesion force.  相似文献   
55.
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.  相似文献   
56.
陈小昕  牛元秀 《中国海事》2013,(10):18-20,23
文中通过探讨船舶物权登记制度中行政权的运行空间,分析船舶物权登记的本质,力争为船舶物权登记的审查方式与审查标准提出一条有效解释的路径。  相似文献   
57.
运用升力线、升力面以及面元法理论为海事40m级巡逻船设计新型螺旋桨。采用给定环量分布进行螺旋桨理论设计,并通过桨模敞水试验和实桨装船后的实船测试验证该桨的理论设计方法。实船测试主要通过2条相同船型的实船,分别加装图谱桨和理论桨进行航速、轴功率、艉部振动对比测试,用实船试航的试验数据对比分析理论桨相对图谱桨的性能指标。结果表明:采用理论方法设计的螺旋桨相对原来的图谱方法,与船型匹配得更加精确,实船的螺旋桨效率约提高2%;船体艉部振动约减小5dB。  相似文献   
58.
ABSTRACT

Port activity plays an important role in facilitating international trade. Sufficient capacity is indispensable for a port to attract flows to a region and retain them. The capacity decision is the result of a trade-off between investment and waiting costs. Traditional methods to value expansion projects do not deal adequately with managerial flexibility in the face of uncertainty from different sources in the complex port environment. In this paper, real options (RO) models are identified as an alternative method to making project valuations and investment decisions, as they attribute the correct value to managerial flexibility under uncertainty. In order to be able to build and use such RO models for port capacity investment decisions, the sources and implications of uncertainty in the port and the different RO model specifications need to be understood. To this end, both the literature about uncertainty in the port context and the literature about real options models are reviewed in order to provide researchers who want to build their own decision-making models, with the necessary knowledge of both fields. The review makes clear that the complex interactions in and competition between the logistics chains and their actors coming together in ports have significant impacts on port capacity. Uncertainty is also caused by uncertain international trade flows and changes in legislation following new technologies and environmental impacts. An analysis of the components of some general RO models shows how the options of flexible output, investment size and timing are valued by RO models in a setting with demand uncertainty. Moreover, the review presents researchers with insights in how to deal with cooperative and competitive interactions in the chain, time to build, cyclical markets and legislation changes. It also shows how to value the expansion and the phased investment options. The new insights resulting from this review are subsequently combined in a framework that serves as a guideline to build RO models for port capacity investments. Finally, an exemplifying application of the framework is used to build an actual port capacity investment decision model.  相似文献   
59.
朱勇  吴华 《隧道建设》2014,34(7):661-667
为全面比较、分析成兰铁路云屯堡隧道采用合修(单洞双线)与分修(双洞单线)2种建设方案的优劣,针对云屯堡隧道进出口相连工程已开工建设的施工现状,以及隧道长度大于20 km的特点,根据隧道的地形、地质条件、辅助坑道设置状况,从防灾救援、工程投资、施工风险控制、施工组织、支护结构对软岩大变形的适应性、结构抗震、弃碴与环保、运营通风8方面进行了技术经济比较。经过综合比较和分析,得出云屯堡隧道可采用合修方案修建的结论。  相似文献   
60.
针对新一代舰载指控系统对软件集成能力和水平的要求,提出了基于服务总线的舰载指控系统集成方法,分析了服务总线的体系构架和实时服务总线的模型,以及面向服务的舰载指控系统体系结构和服务集成实施方法.  相似文献   
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