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31.
介绍了自主开发的“ERP”系统,及与之匹配的“取货制”物流配送,解决了在一条柔性装配线上装配650种以上机型混装问题,实现了企业计划、定单、技术准备、财务、质量和制造等的核心业务的网络控制,提高了企业的整体竞争力。  相似文献   
32.
高速列车通过隧道时压力波动过程的模型试验   总被引:5,自引:0,他引:5  
文章通过模型试验对高速列车通过隧道时产生的复杂压力场进行了模拟,并对试验结果中的压力及压力梯度曲线进行了分析,将其中的压力波动情况和列车的运行情况相结合,较为清晰地对这一过程进行了描述和解释.  相似文献   
33.
桥面防水粘结材料性能研究   总被引:1,自引:1,他引:1  
通过对防水粘结材料FYT、高剂量SBS改性沥青、环氧沥青3种材料的室内模拟试验研究,对比了防水粘结材料的剪切强度、拉拔强度和老化性能。本文推荐采用高剂量SBS改性沥青作为高速公路水泥混凝土桥面沥青铺装防水粘结材料。  相似文献   
34.

The shared taxi is a special public transport mode, typical of Chilean cities. It operates with cars offering a maximum capacity of four seats, a predefined coverage area and a route that is fixed in principle, but can be adapted to meet passengers’ needs. During a normal day in Santiago, almost 700,000 trips use shared taxis during one of their stages. This represents about 4% of the total trips made in the city, and this modal share increases in zones and periods with low Metro and bus coverage. This study is a first attempt at studying shared taxis as a relevant transport alternative, analysing its main attributes and modelling its demand. With this purpose, after an analysis of the network and its operation, a revealed preference survey (including perceptual indicators) was applied to public transport users in Santiago who had shared taxi as a feasible alternative. Results show a positive evaluation of the mode’s unique attributes, such as the possibility of travelling seated, reducing transfers and alighting at a convenient destination. The subjective valuation of the attributes derived from the models confirm the strong penalty assigned by Chilean users to alternatives implying transfers or increased walking times. The analysis also shows that studying the characteristics of shared taxi users is relevant in a discussion about its regulation and modernization, considering that, while it is desirable to preserve its positive attributes, this should be done in a context of efficient integration with the rest of the transport system.

  相似文献   
35.
We estimated the benefits associated with reducing fatal and severe injuries from traffic accidents using a stated choice experiment where choice situations were generated through a statistically efficient design. Specifically, the risk variables were defined as the expected annual number of vehicle car-users that suffered their death or were severely injured in a traffic accident. In addition, and differing from previous research, the number of pedestrians that died or were severely injured in traffic accidents per year was also included as a risk attribute in the choice experiment, to attempt at measuring drivers’ willingness to pay to reduce the risk of hitting pedestrians in a crash. The empirical setting was a choice of route for a particular trip that a sample of car drivers periodically undertakes in Tenerife, Spain. Models were estimated accounting for random taste heterogeneity and pseudo-panel data correlation. The median of the distribution of simulated parameters was used to obtain a representative measure for the monetary valuation of risk reductions. We found that the ratio between the values of reducing the risk of suffering a serious injury and that of reducing a fatality was approximately 18 %. Further, and quite novel, we also found that the value of reducing a pedestrian fatality was 39 % of the value of reducing a car occupant fatality.  相似文献   
36.
本文以非均匀有理B样条基函数作为参数体属性,并结合非均匀控制点网格,建立了适用于船体几何的NFFD变形技术。重点阐述了NFFD方法的基本原理和变形规则,并以矩阵表示方法为基础构建了数学模型。研究了控制点数量和分布对变形结果的影响,增加了控制点变形几何的能力并获得了更大的设计空间。最后,以某CNG运输船为例完成了球鼻艏、船艏和船艉部分几何的自动变形。本文的工作为船型优化提供了良好的变形工具。  相似文献   
37.
38.
Users’ loyalty to public transit service is fundamental to promote its popularity in the transportation market. A four-step analytical framework is advanced to investigate the importance of service attributes that heterogeneous transit user segments place on their public transit service loyalty, measured in terms of overall satisfaction and re-use intention. Critical service attributes perceived by transit users that are relevant for loyalty enhancement are explicitly determined, which vary between user segments. It is suggested that the design of strategies aimed to promote the use of public transit by increasing user loyalty towards transit service be targeted at specific attributes that contribute most to loyalty and specific user segments whose original loyalty level is significantly different to others.  相似文献   
39.
客车发生正面碰撞事故约占客车碰撞事故的50%~60%。利用LS-DYNA软件,建立了包括假人、安全带和安全气囊在内的大客车车体有限元模型,对不同速度下营运大客车的正面碰撞特性进行了模拟仿真计算,分析了无任何保护措施、佩戴安全带及佩戴安全带且安全气囊起爆三种事故形态下乘员头部HPC值、胸部压缩量和大腿骨轴向接触力等伤害值。研究结果表明,安全带对于驾驶员的保护意义重大,为营运大客车乘员保护设计以及合理制定营运大客车正面碰撞法规提供数据参考。  相似文献   
40.
铑催化剂用水合三氯化铑的制备   总被引:1,自引:0,他引:1  
水合三氯化铑是制备铑催化剂的关键原材料之一。随着化工及汽车行业的发展,对铑催化剂有了更多的需求,由此对水合三氯化铑的需求量越来越大。本文综述了当前铑催化剂的应用,以及其原材料水合三氯化铑制备技术的研究进展,并且展望了未来水合三氯化铑的制备技术。  相似文献   
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