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1.
广州地铁工程是国内数个重要的大型城市基础建设项目之一。目前对于这种复杂的大型工程项目,迫切需要一个成熟可靠的公开招标评估系统。根据广州地铁工程的实际招标评标数据,提出应用人工神经网络(ANN)建立地铁施工招标综合评估模型。BP神经网络具有很强的自学习和自适应能力,可以精确地迫近复杂的非线性动态函数。经过训练网络,基于BP网络的模型成功量化了主观和定性的技术评估指数,得出较满意的评估结果。该模型可以通过增加样本提高精度,从而应用在地铁和其他类似建设项目招标中。  相似文献   
2.
1917-1924年苏俄对华政策演变是从世界革命理想向维护国家利益的现实转变.在中东铁路问题的解决过程中,当时的国际形势、苏俄国内形势、北京政府的阶级立场和中国混乱的政局,都影响着中东铁路问题的解决.  相似文献   
3.
This paper examines the related problems of the capitalization and financial performance of the railway companies in the inter-war period. It examines the critics' view that the railways were over-capitalized, and places the debate in context by analysing the dividend and accounting policies of the companies and the consequences for investment. It also examines the conflicting views of railway management and shareholders over capital expenditure. The paper concludes that the railways were both financially over-capitalized and physically under-capitalized, and so faced very serious financial problems that were incapable of resolution within the existing ownership structure.  相似文献   
4.
A yard template determines the assignment of spaces in a yard for arriving vessels. Fluctuation of demand for freight transportation brings new challenges for making a robust yard template when facing uncertain maritime market. A model is proposed for yard template planning considering random numbers of containers that will be loaded onto vessels that visit the port periodically. Traffic congestions and multiple schedule cycle times for vessel arrival patterns are also considered. Moreover, a meta-heuristic method is developed for solving the model in large-scale cases. Numerical experiments are conducted to validate effectiveness and efficiency of the model.  相似文献   
5.
China launched the Shanghai Free Trade Zone (FTZ) Program on September 29, 2013 in a bid to reduce administrative interventions, ease restrictions on investments, further open up its financial system, and internationalize its currency to booster shipping, logistics, and commerce. This article aims to present a background of the Shanghai FTZ and some reflections on it. China’s economic reconstruction has made a major impact on its port cities. Competitions between ports are gradually evolving into competitions between supply chains, with ports no longer considered as isolated links in the transport chain but rather as integral links in the supply chain. Ports are transitioning into fourth-generation ports with the establishment of logistics and value-added activities, which are developed in conjunction with local industrial and service businesses. In this trend, China’s port cities can provide a wide range of value-added services and become centers of commodity flow, capital flow, and information flow. Specifically, the combined effects of driving the development of peripheral industries and actively coordinating the activities of relevant parties help regulate the operations of the entire supply chain to obtain potential value-added benefits. The implementation of the Shanghai FTZ will not only stimulate trade but will also bring increased shipping and finance opportunities to the city. With free trade as the new direction and focus of the country’s economic initiatives, the Shanghai FTZ will hopefully lay the groundwork for a new round of reforms and restructuring of the Chinese economy.  相似文献   
6.
This study intended to discuss the interactive influence of the emergence, transformation and decline of the railway in Kaohsiung Port on urban development, the population, the activities and the economy in the region during the period of 1895–2010, from the perspectives of urban planning, railway development, population and industry. This study used the crossover analysis method, and used the factors of railway development and urban planning, within a fixed time period, to explore the chain dependence relationship among the industry, the population, the regional economy and the railway stations in Kaohsiung city. This study found that urban planning, economic development, railway development and industry have an interactive influence on the overall urban development. Urban planning promotes the rapid growth of the population, and economic development propels the growth and shaping of the regional economy, thus increasing employment opportunities. In addition, the railway development process moves forward with urban development.  相似文献   
7.
This article studies a container drayage problem with flexible orders defined by using requiring and releasing attributes as a unified formulation of various order types. A determined-activities-on-vertex (DAOV) graph introduces a temporary vertex set to formulate different truck statuses. The problem is formulated as a mixed-integer nonlinear programming model based on the DAOV graph. Four strategies including a window partition based (WPB) strategy are presented and evaluated extensively to solve the problem. Results indicate that the WPB method could solve the problem effectively and efficiently. Furthermore, this method is robust considering the operating time biases compared to other algorithms.  相似文献   
8.
包西高速铁路作为我国"八纵八横"高速铁路通道中重要的纵向通道之一,建成后呼包鄂城市群和关中平原城市群将实现有效连接。鄂尔多斯市为典型的"一城双核"城市,包西高速铁路的引入将对地区客运布局产生较大影响,根据鄂尔多斯地区城市及铁路现状、城市总体规划及交通规划,结合地区客运量及特点,提出地区内包西高速铁路引入方案及车站设置方案,确定合理的引入及客站布点,研究地区内高速铁路客站布局,结合地区客流特点,确定高速铁路车站分工;合理确定引入地区线、站位方案将有助于完善鄂尔多斯铁路枢纽的客运铁路布局,有助于完善鄂尔多斯地区高速铁路网络,提升呼包鄂城市群的辐射效应,促进城市建设和经济发展。  相似文献   
9.
The present study examines the location of emergency rescue problems for urban ambulance and railway emergency systems. The proposed model considers probabilistic rescue demand, independent busy fractions of ambulances, and the corresponding risk levels in railway segments. We formulate the proposed model using fuzzy multi-objective programming and solve it using a generic algorithm and a non-dominated sorting genetic algorithm-II. Computation results are analyzed by applying the model to a real-world Taiwan railway system. Analytical results demonstrate that a proper adjustment of the rescue resource location improves rescue effectiveness for railway rescue and urban medical service demand.  相似文献   
10.
中资企业面向非洲铁路市场,多以"广覆盖"的形式投入开发,一定程度上造成了资源浪费。为优化中资企业在非洲铁路市场布局以及资源配置,在分析非洲铁路发展现状、铁路网发展影响因素基础上,基于铁路系统需求度、铁路发展需求度分析非洲铁路发展需求,提出了非洲大陆49个国家高、较高、中、低4个等级的铁路发展需求度,同时提出非洲铁路市场开发策略建议,即:优化非洲铁路市场开发资源配置,分区域实施铁路市场开发及项目建设,创新合作模式、拓宽资金来源。  相似文献   
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