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排序方式: 共有1212条查询结果,搜索用时 93 毫秒
21.
温颂杰 《中小企业管理与科技》2021,(1)
随着社会经济的飞速发展和城市人口密度的不断增加,城市建筑的楼高在不断增加,在扩容城市人口的同时,也在一定程度上提升了高层建筑物遭受雷击的概率。基于此,论文结合具体工作经验,对建筑电气安装工程防雷接地施工技术的相关问题展开深入研究。 相似文献
22.
崔新军 《中小企业管理与科技》2021,(9)
近年来,随着我国经济的迅速发展,电气工程技术标准不断提升,对于技术的优化提出了更高的要求。电气工程技术在各行各业都得到了有效的应用,该技术的重要性不言而喻。尤其是制造业,其对于电气工程技术的依赖程度较高。所以在电气工程以及电气自动化控制系统的优化中,如何提高运行效率以及让设备稳定运行是当前工程师们所必须考虑的问题。 相似文献
23.
本文介绍了赢得值法的基本概念及基本原理,并结合工程实例对赢得值法在项目管理中的应用进行了探讨。进一步证实了赢得值法作为一项项目管理技术的可行性。 相似文献
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25.
This paper analyzes the effects of cell phone usage and economic freedom on motor vehicle death rates by estimating regression models on data for three years across 38 countries. The models incorporate a representative set of motor vehicle fatality determinants. Results indicate that cell phone use has a statistically significant nonlinear impact on highway death rates and that economic freedom does not appear to have an effect. 相似文献
26.
Jaeyoung Jung R. Jayakrishnan 《International Journal of Sustainable Transportation》2017,11(8):567-581
Electric vehicles (EVs) are energy efficient and often presented as a zero-emission transport mode to achieve long-term decarbonization visions in the transport sector. The implementation of a sustainable transportation environment through EV utilization, however, requires the addressing of certain cost and environmental concerns such as limited driving range and battery-charging issues before its full potential can be realized. Nevertheless, a specific type of use of EVs, namely in taxi services, may elicit positive public opinion, as it promises a commitment toward sustainability in urban life. In light of this, this study proposes an integrated approach that combines EV operation with a conceptual design for shared-ride taxi services. As some productivity loss may be naturally expected due to the time spent in charging, it is important to look at whether such performance loss from the passenger and system standpoints can be offset with ingenuity in operational design. In this study, an EV taxi charge-replenishing scheme that can be coupled with a real-time taxi-dispatch algorithm is designed. The proposed EV charging schemes for taxi services are studied via simulations and the effects of the limited driving range and battery-charging details are examined from a system performance viewpoint. The simulation study also reveals illustrative results on the impact of the EV taxi fleet's operation on the charging system. Next, a real-time shared-taxi operation scheme that allows ride sharing with other passengers is proposed to maximize the operational efficiency. The simulation results suggest that the shared-taxi concept can be a viable option to improve on the limitations caused by EV operation. In addition, the importance of projected charging demands and queue delays at different charging locations are also addressed. Some limitations and a future research agenda are also discussed. 相似文献
27.
Nisrine Mouhrim Ahmed El Hilali Alaoui Jaouad Boukachour 《International Journal of Sustainable Transportation》2019,13(6):419-432
Electric vehicles (EV) use an eco-friendly technology that limits the greenhouse gas emissions of the transport sector, but the limited battery capacity and the density of the battery are the major barriers to the widespread adoption of EV. To mitigate this, a good method seems to be the innovative wireless charging technology called ‘On-Line EV (OLEV)’, which is a contactless electric power transfer technology. This EV technology has the potential to charge the vehicle’s battery dynamically while the vehicle is in motion. This system helps to reduce not only the size of the battery but also its cost, and it also contributes to extending the driving range before the EV has to stop. The high cost of this technology requires an optimal location of the infrastructure along the route. For this reason, the objective of this paper is to study the problem of the location of the wireless charging infrastructure in a transport network composed of multiple routes between the origin and the destination. To find a strategic solution to this problem, we first and foremost propose a nonlinear integer programming solution to reach a compromise between the cost of the battery, which is related to its capacity, and the cost of installing the power transmitters, while maintaining the quality of the vehicle’s routing. Second, we adapt the multi-objective particle swarm optimization (MPSO) approach to our problem, as the particles were robust in solving nonlinear optimization problems. Since we have a multi-objective problem with two binary variables, we combine the binary and discrete versions of the particle swarm optimization approach with the multi-objective one. The port of Le Havre is presented as a case study to illustrate the proposed methodology. The results are analyzed and discussed in order to point out the efficiency of our resolution method. 相似文献
28.
温州制造业转型升级对机电产品营销提出新的要求,课题组对温州地区机电行业企业进行了调查研究,掌握了温州企业对机电产品营销人才的需求状况,并在此基础上进行机电产品营销专业建设。 相似文献
29.
本文为了解决物联网所连接对象的多样性带来的标识体系存在不兼容、相互矛盾的问题,基于车联网RFID汽车电子标识的使用特点,创造性地提出将OID编码和汽车电子标识编码相结合的方案。首先简单介绍了基于发证机构及时间和基于汽车VIN码的两种OID编码规则;然后提出了OID编码在汽车电子标识芯片中的规划,主要是内存分配方案;最后介绍了相应区域的读写操作的具体方法。 相似文献
30.
本文介绍了汽车尾气对人类健康和生态环境的危害,及其生成机理和影响因素并简述汽车尾气治理与发展。 相似文献