基于人工神经网络的地铁施工招标综合评估模型

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。     

苏俄在中东铁路问题上对华政策演变(1917-1924年)

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.     

'An awkward fence to cross': railway capitalization in Britain in the inter-war years

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.     

An economic–geographic assessment of the potential for a new air transport hub in post-Gaddafi Libya

Post-war Libya is faced with the challenge of adopting an air transport strategy for the future. One issue is how to address projects inaugurated under the Gaddafi government, such as the terminal extension at Tripoli International Airport. Additionally, the state-owned Afriqiyah Airlines had been establishing a niche hub in Tripoli before the 2011 war, but this development has subsequently been stalled.Against this background, we analyse the prospects of an air transport hub operation in Libya, focusing on traffic between Africa and Europe, from a bird’s-eye economic–geographic view. First, a literature review is undertaken to identify general success factors for air transport hubs. Second, a weighted average distance penalty (WADP) indicator is developed and applied to Tripoli as a potential hub location. This indicator considers all 4755 O&Ds between Europe and Africa with more than 100 passengers in 2012. For sensitivity reasons, alternative WADPs are estimated for the 3209 traffic flows not including North Africa and for (forecasted) future air traffic demand in 2020. The results for Tripoli International Airport are benchmarked against competing hub locations, such as Algiers, Cairo, and the major European airports. We conclude by discussing the implications of the current and anticipated future security and economic situation in the country.     

Railway development from the Japanese occupation period to the present – using Kaohsiung city as an example​​​​​​​​

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.     

Sustainable hub location under mixed uncertainty

This paper addresses a novel sustainable hub location problem (SHLP) in which two new environmental-based cost functions accounting for air and noise pollution of vehicles are incorporated. To cope with uncertain data incorporated in the model, a mixed possibilistic–stochastic programming approach is proposed to construct the crisp counterpart. A simulated annealing (SA) and an imperialist competitive algorithm (ICA) with a new solution representation are developed to solve real-sized instances whose performances are compared with a proposed lower bound. Finally, some computational experiments are provided to demonstrate the effectiveness of the proposed model and solution approaches.     

包西高速铁路引入鄂尔多斯地区方案研究

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。     

A strategic planning model for the railway system accident rescue problem

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.     

A new hub and spoke system proposal: A case study for Turkey's aviation industry

In this paper, we are proposing a multi-objective mathematical model for the selection of a newly constructed hub and spoke system. The objectives of this model are maximizing aircraft utilization and revenue whilst reducing the commercially infeasible network detour factor. The sensitivity analysis of the model is tackled using weights related to the objectives as well as the network detour factor. The number of available aircraft and the range that an aircraft can reach are also considered in this model. Since Istanbul has already got a hub and spoke system with busy airports on both sides of the city, the model is applied to three other major cities of Turkey, Ankara, Antalya, and Izmir. The test data consists of over 90 cities in Europe and in the Middle East. The data includes unit passenger revenues and operating costs for the segments, distances between cities and hubs, expected load factors and flying times of segments. The scenarios are tested under specific expectations of airline network experts and the results are visualized by using Pareto front graphs. Compared to other candidates, Antalya stands out as a good choice for a new hub and spoke system in Turkey. The results of this model could be helpful for airlines and other airports in Turkey in order to identify their potential and competitive position in relation to their counterparts.     

非洲铁路发展需求分析与市场开发策略

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。