Total cost analysis: An alternative to benefit-cost analysis in evaluating transportation alternatives

This paper explains the theory in support of total cost analysis (TCA) to compare transportation system alternatives. The full costs of each alternative are first aggregated, including travel time costs and monetizable environmental and social costs. Many costs which are considered on the benefits side of the equation in benefit-cost analysis (BCA) as "cost savings" are brought over to the costs side. Total cost differences among alternatives are then traded off against their estimated non-monetized benefits or impacts, just as a consumer trades off product quality against cost before deciding which product he or she will buy. One advantage of TCA over traditional BCA is that the concept of "total cost" is more easily understood by the public and by political decision-makers than BCA concepts such as "net present worth", "benefit-cost ratio" and "internal rate of return". A second advantage is that there is no suggestion that all "benefits" have been considered; decision-makers are free to use their own value judgements to trade off total cost against non-monetizable social, environmental and economic impacts, just as they trade off quality and convenience against cost when purchasing goods and services in their roles as consumers. The TCA approach is demonstrated in this paper through a case study of two systemwide alternatives for the Baltimore, MD urban area.     

Lane changing intention recognition based on speech recognition models

Poor driving habits such as not using turn signals when changing lanes present a major challenge to advanced driver assistance systems that rely on turn signals. To address this problem, we propose a novel algorithm combining the hidden Markov model (HMM) and Bayesian filtering (BF) techniques to recognize a driver’s lane changing intention. In the HMM component, the grammar definition is inspired by speech recognition models, and the output is a preliminary behavior classification. As for the BF component, the final behavior classification is produced based on the current and preceding outputs of the HMMs. A naturalistic data set is used to train and validate the proposed algorithm. The results reveal that the proposed HMM–BF framework can achieve a recognition accuracy of 93.5% and 90.3% for right and left lane changing, respectively, which is a significant improvement compared with the HMM-only algorithm. The recognition time results show that the proposed algorithm can recognize a behavior correctly at an early stage.     

Alternative fuels for transportation

The alternatives to the oil based fuels for transportation are considered and analysed. These are the synthetic fuels, made from coal, the liquid petroleum gases of propane and butane, compressed natural gas and methanol. The problems associated with the use of electric vehicles are discussed; the main problem being that of range.

The possible use of hydrogen as a fuel is analysed in some detail. Since its supply can be tied directly to nuclear energy sources, rather than hydrocarbon feed stocks, it could be an alternative in the long term. The main problems of the storage of hydrogen on the vehicle and of its propensity to “back‐fire” into the engine intake are discussed. The first can be ameliorated and the second eliminated by dual fuelling; with petrol. It is advocated that the on‐board storage of hydrogen be by the use of hydrides for private cars. However, it is expected that it may be as liquid hydrogen for some forms of transport and will certainly be in this form for aircraft.     

An integrated framework for embedding large-scale dynamic traffic assignment models in advanced traveler information systems

In recent years, increasing attention has been drawn to the development of various applications of intelligent transportation systems (ITS), which are credited with the amelioration of traffic conditions in urban and regional environments. Advanced traveler information systems (ATIS) constitute an important element of ITS by providing potential travelers with information on the network's current performance both en-route and pre-trip. In order to tackle the complexity of such systems, derived from the difficulty of providing real-time estimations of current as well as forecasts of future traffic conditions, a series of models and algorithms have been initiated. This paper proposes the development of an integrated framework for real-time ATIS and presents its application on a large-scale network, that of Thessaloniki, Greece, concluding with a discussion on development and implementation challenges as well as on the advantages and limitations of such an effort.     

基于AHP的空空导弹武器系统作战能力研究

介绍作战能力的基本概念,分析影响空空导弹武器系统作战能力的因素;提出层次分析法进行作战能力评估的步骤和准则,运用层次分析法建立能力综合评价模型;并通过典型武器系统评价实例,利用提出的算法对方案进行了综合分析,分析结果验证了方法的合理有效。     

高铁客运站旅客导向标识系统优化算法研究

高速铁路的快速发展,对客运站旅客导向标识系统提出更高的要求.由于高速铁路客运站的功能和布局比较复杂,为了更好地为旅客提供便捷、高效的服务,本文根据高铁客运站运营管理实际需求,采用智能优化算法对旅客导向标识系统进行优化设计.首先,以区域诱导信息量最大为目标,建立了旅客导向标识布设位置选择模型;其次,进行退火-遗传算法设计并求解,找到了较优的布设位置;最后,以北京南站地下一层的导向标识系统为例进行实例分析,并且与遗传算法标识位置的布设相比较,验证了退火-遗传算法的可行性和有效性,为高速客运站导向标识系统的优化设计提供了科学依据.     

便携式网管在传输设备安装调试及故障处理中的应用

针对传输设备的调试及故障处理,以京九铁路电气化改造工程通信施工中的操作为例,结合便携式网管的使用介绍了一些常用的技巧与方法。     

国外基于MBSE的列车领域研究现状探析

介绍了基于模型的系统工程的定义和发展历程.分别对庞巴迪和阿尔斯通两家公司在MBSE方面的研究和应用情况进行了分析,具体分析其建模工具和建模实例,还分析了Connecta和Safe4Rail项目的实施过程以及主要的研究内容.分析结果表明,MBSE已经在国外的列车领域经历了学习、探索和应用推广的过程,并在新产品的研发过程中...