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The second-best congestion pricing schemes including common optimum, one cordon, and multiple cordons schemes are compared with the first-best optimum pricing scheme. A cross-subsidy effect exists in these second-best pricing models. However, the scheme with more cordons will diminish the cross-subsidy and approach an efficient and equitable outcome. The relative efficiency of a cordon pricing scheme for the case of Taipei metropolis is very high. One single cordon yields excellent performance of 93% relative efficiency. There might be some factors causing the good results: the uncongested traffic condition, the linear unit distance cost in traffic flow forming a nonlinear cost function, and the trip demands with continuous space and the same destination (the central business district) in the network. 相似文献
965.
为研究舱壁布置形式对圆柱壳结构声学性能的影规律,文章应用有限元方法对等间距与不等间距分舱圆柱壳模型的振动响应进行了计算,以此为输入可计算获得壳体的均方法向速度级声学传递函数,并在典型频率处应用波数谱分析方法将壳体空间域振动场转换到波数域上,对壳体的振动进行波形分离与量化,分析获得了舱壁等间距布置与不等间距布置圆柱壳在典型激励下的结构声学性能,并解释其机理.研究表明:对垂向激励,圆柱壳不等间距分舱相比等间距分舱具有较好的结构声学性能,但对轴向激励,两者区别不明显.若将不等间距分舱与局部结构补强措施相结合,则可使得圆柱壳在两典型工况下均能获得更优的结构声学性能. 相似文献
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考虑连接器作为超大型浮体最为薄弱的构件之一,研究带有柔性夹层连接器的力学特性,旨在明确柔性夹层对连接器的刚度和应力变化的影响.通过建立钢与柔性夹层的本构模型,采用接触力学分析手段,对连接器进行力学分析,分别获得超弹性橡胶和尼龙作为柔性夹层时连接器的力学特性和刚度变化曲线,并获得不同厚度,初始弹性模量和泊松比对这一结果的影响程度.分析发现,超弹性橡胶与尼龙对于连接器的应力大小具有显著影响,采用超弹性橡胶和尼龙夹层时,连接器的应力水平与应力分布也明显不同,同时材料参数的变化对于连接器的刚度变化影响较大.可根据实际需要,对柔性夹层材料进行参数优化,既得到合理的连接器刚度,又将连接器应力水平控制在合理范围内. 相似文献
968.
The job satisfaction level (JSL) of self-employed container truck drivers (SCTDs) is vital to the container trucking industry’s (CTI) stability in China. An anonymous field survey of 645 SCTDs was conducted at Shanghai Port. Three ordered probit models were, respectively, developed to analyze the drivers’ JSLs, their attitudes, and reactions to a CTI downturn. This study contributes to the literature that the demographic variables were not statistically significant for the SCTDs’ current JSLs, while higher income SCTDs with fewer expenses were expected to have higher JSLs. During an industry downturn, drivers with families in Shanghai showed more job dissatisfaction. More working hours, lower income, expensive diesel fuel, a high consumer price index (CPI), and a low freight-to-distance ratio (FDR) significantly lowered the JSLs. An increase in the price of diesel fuel and the CPI, and a lower FDR exposed the industry to risk and instability. Additionally, credible evidence indicated that as the dissatisfaction levels of SCTDs rise in a downturn, SCTDs implement more practical measures that may negatively affect the industry’s stability as well as society’s. Based on these findings, managerial or policy implications were proposed to efficiently improve SCTDs’ JSLs and CTI stability in Shanghai. 相似文献
969.
Accompanying the widespread use of the Internet, the popularity of e-commerce is growing in developing countries such as China. Online shopping has significant effects on in-store shopping and on other personal activity travel behavior such as leisure activities and trip chaining behavior. Using data collected from a GPS-based activity travel diary in the Shangdi area of Beijing, this paper investigates the relationships between online shopping, in-store shopping and other dimensions of activity travel behavior using a structural equation modelling framework. Our results show that online buying frequency has positive effects on the frequencies of both in-store shopping and online searching, and in-store shopping frequency positively affects the frequency of online searching. Frequent online purchasers tend to shop in stores on weekends rather than weekdays. We also found a negative effect of online buying on the frequency of leisure activities, indicating that online shopping may reduce out-of-home leisure trips. 相似文献
970.
20年来,随着规范法学对交通现实问题回应愈发疲软,交通法学经历了从法教义学的闭环到法社会学的交叉研究的范式变迁.管理学的理论供给引领交通治理模式升级转型,社会协同治理、"大交通"执法模式应运而生.信息技术、医学、微电子学、环境学等自然科学研究方法从立法需求面向的碎片化摘取,走向交通法学研究方法论层面的全面进驻.心理学、... 相似文献