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通过对全球乘用车传动及底盘结构进行统计分析,给出了乘用车驱动方式与车长、手动变速器与车长、自动变速器与车长、前单横臂后扭力梁组合与车长、前单横臂后多连杆组合与车长、前双横臂后多连杆组合与车长、装空气弹簧车辆与车长关系的统计数据。论述了乘用车不同车身形式所采用的弹性元件与稳定杆类别,以及乘用车所采用的不同制动方式。 相似文献
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Single policies or entire policy packages are often assessed using different methods aiming at a quantification of effects as well as the detection of undesired outcomes. The knowledge of potential impacts is essential to take informed policy actions. Hence, there is a constant need for efficient assessment approaches to support policy decision-making. A broad range of such assessment methods is used in policymaking. Some of them are using quantitative data; others are characterized by qualitative information, observations or opinions. Practical experiences with transport policy prove that these methods all have their pros and cons, but none of them are able to detect the full range of effects. This leads to important questions this article deals with, such as what are the strengths and limitations of the different tools and methods for assessing impacts, and how should different approaches be integrated into the policymaking processes?We analyze the ability of assessment methods to detect different kinds of intended and unintended effects, and introduce the concepts of structurally open (mainly qualitative) and structurally closed (mainly quantitative) methods. It is argued that these concepts support making the pros and cons of the tools and methods more explicit and, thus, allow integrating the different tools and methods into the process of policy packaging. Based on a policy package example, we provide practical recommendations on how to integrate different assessment methods adequately and show that both quantitative and qualitative tools should be used in different phases of the process. The main recommendation is to alternate the application of assessment methods with structurally open methods used in the beginning and the end of the policymaking process and applying structurally closed methods in between. 相似文献
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为提高慢行系统规划方法对具体实践工作的指导性和操作性,研究提出基于使用者需求分析的慢行系统规划"需求引导法",用于指导宏观层面和中观层面的慢行系统规划。"需求引导法"的操作过程首先通过分析山水格局和用地结构,建立慢行系统初始方案,其次对初始方案进行需求侧要素点和供给侧要素点两方面的评价,并根据评价结果对初始方案进行多轮优化调整,从而构建宏观层面供需平衡的慢行骨架系统。中观层面根据组团功能、慢行交通集聚程度划分慢行分区,并结合路网条件供给,提出各分区的慢行发展模式。最后以厦门市为例说明"需求引导法"的操作过程。 相似文献
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建筑结构识图和钢筋算量是高职土建类专业学生的核心技能之一。通过聚焦"专业岗位职务能力",对课程重新定位,结合工作岗位任务进行教学内容选取并实施综合考核方式,使学生的知识技能更加贴合专业岗位需求,并实现学生学习热情的长效性,让学生更加适应市场需求,取得了较好的教学效果。 相似文献
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Car following models have been studied with many diverse approaches for decades. Nowadays, technological advances have significantly improved our traffic data collection capabilities. Conventional car following models rely on mathematical formulas and are derived from traffic flow theory; a property that often makes them more restrictive. On the other hand, data-driven approaches are more flexible and allow the incorporation of additional information to the model; however, they may not provide as much insight into traffic flow theory as the traditional models. In this research, an innovative methodological framework based on a data-driven approach is proposed for the estimation of car-following models, suitable for incorporation into microscopic traffic simulation models. An existing technique, i.e. locally weighted regression (loess), is defined through an optimization problem and is employed in a novel way. The proposed methodology is demonstrated using data collected from a sequence of instrumented vehicles in Naples, Italy. Gipps’ model, one of the most extensively used car-following models, is calibrated against the same data and used as a reference benchmark. Optimization issues are raised in both cases. The obtained results suggest that data-driven car-following models could be a promising research direction. 相似文献
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在养护工程实践中以最大限度提高道路使用性能为目的,不断应用新技术、新材料、新工艺.为保证全线道路的使用功能和通行能力起到了积极的作用。 相似文献