排序方式: 共有117条查询结果,搜索用时 3 毫秒
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高速铁路建设中,会从工程实施的难易程度、线路方案中控制工程的多少、工程投资等多个方面出发,对多个可行性方案进行比较,以选定最合适的线路方案.其中,工程投资是线路方案决策的重要依据.高速铁路中桥梁占比大,为了快速给出桥梁工程投资,为方案决策提供依据,以某山区高速铁路为例,从桥墩平均高度、上部工程特殊结构占比、附属工程、施... 相似文献
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国内关于城市轨道交通运营指标的规范在实际应用中存在部分指标定义不规范、统计方法过时或指标混淆等情况.基于CJ/T81999《城市公共交通经济技术指标计算方法地铁》和GB/T22486-2008《城市轨道交通客运服务》,以举例形式对正点率、客运量、客流量、运营里程和运营线路长度、满载率和列车拥挤度等指标的统计进行了探讨,指出存在的问题并提出相关建议.有关主管部门应抓紧制定轨道交通运营指标统计、计算的国家标准. 相似文献
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以我海军亚丁湾护航任务为背景,文章具体分析了远海使用条件下舰船装备技术保障的要素和影响因素,基于一定的指标选取原则确定了舰船装备技术保障评估指标,建立了相应的评估指标体系层次结构,并对底层指标进行了简要的定量、定性分析,提出了指标分析方法,为舰船装备保障能力评估工作打下基础。 相似文献
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Haoliang Yao 《Coastal management》2013,41(5):458-482
Practical experience derived from current and developing integrated coastal and ocean management (ICOM) initiatives around the world demonstrates that these collaborative and integrated approaches to managing coastal and ocean resources are strongly influenced by various contextual factors including political, administrative, institutional, social, economic, and cultural. A comparative evaluation of two such ICOM initiatives—off the east coasts of Canada and China, respectively—provides valuable insights into how these factors play in the development, implementation, and success of these initiatives in two different settings. The evaluation framework developed and applied in this research focuses on evaluations of governance performance and management capacity, and applies both process- and progress-oriented indicators. Key findings include: (1) The Eastern Scotian Shelf Integrated Management (ESSIM) Initiative focuses on the participatory approach that emphasizes equity and consensus among stakeholders, whereas the Bohai Sea Sustainable Development and Environmental Management (BSSDEM) Program benefits greatly from a comprehensive approach that integrates different governments/departments and bridges among stakeholders; (2) management approaches to ICOM strongly depend on the program objectives/priorities and local circumstances. Moreover, a total of thirteen recommendations are provided for the purposes of strengthening on-going programs and replicating success at a larger scale. 相似文献
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ABSTRACTTransport costs are useful explanatory variables in port choice research. Nevertheless, the availability of such information usually poses a problem. Thus, the formulation of an alternative approach, to be used as a proxy of these variables, would be desirable. The objective of this study is to improve the analysis of container port choice using logit models by adopting physical non-monetary indicators based on maritime distance and ship size. The statistical tests of logit models on port choice using these new variables are compared with the result of using cost variables for the same data set of choice positions. The statistical outcome is good and allows us to present this new approach as a contribution to the literature on port choice modeling. 相似文献
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采用一种基于随机数据的Bootstrap算法对微观排放模型的误差进行分析,准确刻画出模型误差的置信区间,并应用6个评价指标来全面地分析模型的预测效果;最后利用该算法对两个微观排放模型(MEM-P模型和CMEM模型)的预测效果进行了比较. 相似文献
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This paper introduces a methodology for the characterization of ports, employing specifically defined eco-efficiency indicators and combining typically available data (handled cargo, containers and passengers) with ship exhaust pollutants values (mainly NOx, SOx and PM) and anticipated external costs (ECs) due to emitted air pollutants to provide a collective overview of all port-related economic and environmental activities. The results from an applied case study allow a comparative evaluation of 16 selected ports based on 17 different evaluation criteria and denote that the employment of such an overall approach can allow port authorities to improve managerial aspects, potentially lower operational costs and promote reduced environmental effects. 相似文献
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电动汽车滑行制动能量回收过程的驾驶性是车辆纵向动力学瞬态品质的定性描述,为定量评价能量回收制动的驾驶性,对滑行制动过程中的减速特性进行分析,提取了最大减速度、减速滑行距离、最大减速度变化率、减速度变化率稳态占比4个客观指标,并通过相关性分析验证主观评价与客观参数的一致性。基于客观评价指标,利用非线性回归方法建立了主观评价预测模型。通过7台新能源车型共计18种能量回收模式下的综合评价,验证了评价体系的有效性和实用性。结果表明,基于主客观综合分析建立的评价体系能把主观感受和客观数据有机结合,实现驾驶性的量化评价。 相似文献
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本文设计了一种切实可行的红外报警电路装置,闸述了其工作原理,以及提高灵敏度和可靠性的主要措施.研制结果证明.这种报警器设计合理,性能可靠,保密性和抗干扰能力强,使用方便. 相似文献