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781.
This paper concerns the development of a new decision support framework for the appraisal of transport infrastructure projects. In such appraisals there will often be a need for including both conventional transport impacts as well as criteria of a more strategic and/or sustainable character. The proposed framework is based on the use of cost-benefit analysis featuring feasibility risk assessment in combination with multi-criteria decision analysis and is supported by the concept of decision conferencing. The framework is applied for a transport related case study dealing with the complex decision problem of determining the most attractive alternative for a new fixed link between Denmark and Sweden – the so-called HH-connection. Applying the framework to the case study made it possible to address the decision problem from an economic, a strategic, and a sustainable point of view simultaneously. The outcome of the case study demonstrates the decision making framework as a valuable decision support system (DSS), and it is concluded that appraisals of transport projects can be effectively supported by the use of the DSS. Finally, perspectives of the future modelling work are given.  相似文献   
782.
随着我国经济建设的不断发展以及运输系统要求的提高,大量高速铁路在我国广泛修建。然而,在软土区域修建高速铁路,路基施工过程中的整体稳定性一直备受关注。结合工程实例,借助有限元分析的方法,建立三维模型,对路基施工过程整体稳定性进行分析,研究方法及结论能为类似工程设计及施工提供参考依据。  相似文献   
783.
简述了海上平台发电机房通风设计方案中使用噪音分析研究的流程,介绍了建立几何模型、输入数据得到噪音预报,得出分析结果,最终完成设计方案优化,为海上平台发电机房通风设计提供了参考.  相似文献   
784.
Traditionally, the design of mooring lines and risers of floating production systems (FPS) has been performed separately, by different teams, employing uncoupled analysis tools that do not consider the nonlinear interaction between the platform hull and the mooring lines and risers. Design processes have been focused on fulfilling the design criteria of the respective component (mooring/riser) alone, with few or no consideration to the other component, and little interaction between the design teams. Nowadays the importance of employing analysis tools based on coupled formulations is widely recognized, and analysis strategies have been proposed to consider feedback between mooring lines and risers within their respective design processes.In this context, this work details a proposal of one single and fully integrated design methodology for mooring systems and risers for deep-water FPS. In this methodology, the design stages of both risers and mooring lines are incorporated in a single spiral, allowing the full interaction of different teams; mooring design implicitly considers the riser integrity, and vice-versa, leading to gains in efficiency and cost reduction.Different analysis strategies are employed, taking advantage of uncoupled and coupled numerical models. The models generated at the initial/intermediate design stages can be reused in subsequent stages: simpler models are used in the initial stages, and more refined models are gradually introduced, to reach an ideal balance between computational cost and accuracy of results. In the advanced stages, the exchange of information between mooring/riser also allows the definition of criteria for the selection of governing/critical loading cases to be revised and verified in detail. This leads to the reduction of the original loading case matrix, allowing a feasible use of time-consuming fully coupled analysis.Results of a case study illustrating the application of some of the main processes of the methodology are included.  相似文献   
785.
离相封闭母线因高可靠性、经济性和易维护在发电机引出线回路及厂用分支回路得到广泛应用,但在安装、运行中仍会出现一些问题。本文介绍了一起接地故障的查找、分析及处理情况,以为同行提供借鉴。  相似文献   
786.
A number of highly cited papers by Flyvbjerg and associates have shown that ex ante infrastructure appraisals tend to be overly optimistic. Ex post evaluations indicate a bias where investment costs are higher and benefits lower on average than predicted ex ante. These authors argue that the bias must be attributed to intentional misrepresentation by project developers. This paper shows that the bias may arise simply as a selection bias, without there being any bias at all in predictions ex ante, and that such a bias is bound to arise whenever ex ante predictions are related to the decisions whether to implement projects. Using a database of projects we present examples indicating that the selection bias may be substantial. The examples also indicate that benefit–cost ratios remain a useful selection criterion even when cost and benefits are highly uncertain, gainsaying the argument that such uncertainties render cost-benefit analyses useless.  相似文献   
787.
黄静 《交通标准化》2011,(23):80-82
在公路工程正式动工之前,设计单位要根据所收集的数据信息进行方案设计,为后期的施工作业提供合理的指导策略。针对近年来我国公路建设重心向山区转移的特点,以具体的工程案例为指导,采用环境协调理念对山区公路设计的新策略加以分析,为公路设计提供新的思路。  相似文献   
788.
针对竖直式垃圾压实器的设计,阐明了反映垃圾压缩率的压头形状优化目标以及基于加权平均法的综合评价方案,构建了加权平均法的分析模型并确定各指标的加权系数.然后提出了圆形、方形、推铲形和楔形四种压头形式,分别建立对应的垃圾压缩有限元模型,运用加权评分的方法,选择出最优的压头形状,为压实器的结构设计提供了依据.  相似文献   
789.
分析了某企业轮对生产线存在的作业人员与生产设备利用率低的问题,运用基础工业工程中的作业测定的相关方法对车轮生产中的钻辐板孔工序的工时数据进行了分析和整理,运用作业分析法对钻辐板孔工序的人机作业进行了优化与改进,从而得到更为合理的作业方法.  相似文献   
790.
This paper reviews the existing procedures to compute the seasonal factors, growth factors, and the number of automatic traffic recorder stations (ATRs) for developing a statistically reliable traffic counting program. The review is based on, (i) theoretical evaluation of the procedures, (ii) analysis of the results obtained from applying these procedures to extensive real life data, and (iii) experience of past researchers with these methods. The paper primarily deals with existing statistical procedures for determining seasonal factors, since it is believed that these factors play the most important role in estimating Annual Average Daily Traffic (AADTs) from short counts. The procedure of cluster analysis (which is most commonly used to determine seasonal factors) is critically reviewed. The shortcomings of this method motivated the development of a different statistical procedure, based on regression analysis, to determine seasonal factors. It is shown that this newly developed method gives better results than the cluster analysis techniques. Furthermore, separate sections are dedicated to a thorough analysis of determination of number of ATR stations and computation of growth factors.  相似文献   
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