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971.
介绍了郑徐线TJWX-2006微机监测信息平台系统结构,新增系统功能特点,系统菜单结构,调阅数据和测试方法. 相似文献
972.
高速铁路曲线线路车线耦合系统动力学性能仿真分析 总被引：1，自引：0，他引：1
依据系统工程理论,建立高速铁路曲线线路车线耦合系统有限元模型,对曲线线路在高速行车条件下的耦合系统动力学性能进行仿真,研究时速300 km等级高速动车组作用下曲线线路安全与平稳性指标,曲线线路轨道结构各部分的振动响应、列车速度与曲线半径和超高的关系.结果表明动车组以350 km·h-1的速度通过半径为5 500,7 000和9 000 m的曲线线路时,动车组的垂向和横向振动加速度以及平稳性能均满足舒适度要求,而且脱轨系数和轮轴横向力也能满足列车运行安全性要求;钢轨支点的横向力表现为过超高时内轨侧大、外轨侧小,欠超高时外轨侧大、内轨侧小;钢轨、轨枕的垂向和横向加速度随速度增加明显增大,而道床和路基的垂向加速度变化不大;钢轨和轨枕的横向动位移和动态轨距扩大量随速度的增加而增大;相同速度下,曲线半径小的轨道振动相对较大. 相似文献
973.
974.
975.
利用凸轮机构的分析理论，获得了加工ＤＤ６８０系列汽车制动凸轮的轮廓曲线方程和加工该靠模凸轮的刀具中心轨迹方程。利用微型计算机进行了靠模凸轮轮廓曲线的辅助设计，保证了所设计的靠模凸轮的各项精度，采用该方法计算加工靠模凸轮比用作图法精度高，速度快。 相似文献
976.
We solve the problem of tactical supply vessel planning arising in the upstream offshore petroleum logistics. Supply vessels deliver all the necessary materials and equipment to offshore installations from an onshore supply base according to a delivery schedule. The planning of supply vessels should be done so that their number is minimized and at the same time provide a reliable flow of supplies from the base. The execution of a weekly sailing plan is affected by weather conditions, especially in winter time. Harsh weather conditions increase the number of vessels required to perform the operations as well as the service times at the installations, and thus disrupt the schedule, leading to additional costs and reduced service level. We present a methodology for robust supply vessel planning enabling a trade-off analysis to be made between the schedules’ service level and vessels’ cost. The methodology involves the generation of multiple vessel schedules with different level of robustness using an adaptive large neighbourhood search metaheuristic and a subsequent discrete event simulation procedure for the assessment of the service level. To control the level of robustness we developed a concept of slacks and incorporated it into the metaheuristic algorithm. 相似文献
977.
This study analyzes the potential benefits and drawbacks of taxi sharing using agent-based modeling. New York City (NYC) taxis are examined as a case study to evaluate the advantages and disadvantages of ride sharing using both traditional taxis (with shifts) and shared autonomous taxis. Compared to existing studies analyzing ride sharing using NYC taxi data, our contributions are that (1) we proposed a model that incorporates individual heterogeneous preferences; (2) we compared traditional taxis to autonomous taxis; and (3) we examined the spatial change of service coverage due to ride sharing. Our results show that switching from traditional taxis to shared autonomous taxis can potentially reduce the fleet size by 59% while maintaining the service level and without significant increase in wait time for the riders. The benefit of ride sharing is significant with increased occupancy rate (from 1.2 to 3), decreased total travel distance (up to 55%), and reduced carbon emissions (up to 866 metric tonnes per day). Dynamic ride sharing, wich allows shared trips to be formed among many groups of riders, up to the taxi capacity, increases system flexibility. Constraining the sharing to be only between two groups limits the sharing participation to be at the 50–75% level. However, the reduced fleet from ride sharing and autonomous driving may cause taxis to focus on areas of higher demands and lower the service levels in the suburban regions of the city. 相似文献
978.
The aim of this study is to investigate the results of route-recording within the Swiss National Travel Survey in the year 2010. The research questions include the following: (1) What level of accuracy and quality of georouting between addresses can be obtained within Computer Assisted Telephone Interview (CATI)-based national travel surveys? (2) What are the differences between estimated and routed distances for stages? (3) Is it worth it to switch from self-estimated distances to technological solutions in national travel surveys with a comparison between GPS and route-recording? It was found that within the method of route-recording, a high share of address-precise geocodes is a necessity for a successful routing fulfilled by the Swiss National Travel Survey 2010. Secondly, route-recording provides reliable and valid distance measures and is one way to overcome the difficulty in participants distance estimates. Thirdly, in its current form, it is not yet an alternative to GPS in national travel surveys, if one is interested in the actual routes travelled by survey participants. Especially there is development work necessary in the routing of non-motorised travel regarding both digital networks and the survey method. The paper concludes by drawing on the findings of this examination and formulating opportunities for improvement and enhancement. 相似文献
979.
980.