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61.
接触线及承力索终锚线夹的改进探讨   总被引:1,自引:0,他引:1  
通过对传统使用的GLCN250接触线终锚线夹及接头线夹、LBGLJ185终锚线夹及接头线夹存在问题的探讨,对终锚线夹提出了减小楔子的锥度,在楔子内表面加工内螺纹,加宽空心楔子开槽宽度等改进措施。  相似文献   
62.
电子海图快速显示方法研究   总被引:6,自引:1,他引:5  
关劲  张勇刚  李宁  曾海涛 《中国航海》2004,(4):57-59,70
根据电子海图的数据特点和单幅电子海图调图显示原理,提出了一种多幅电子海图拼图模式下的快速显示方法。该方法运用了计算机内存位图技术和内存缓冲技术,提高了电子海图显示速度和显示效果。该方法已被运用到某新型电子海图系统,并被证明能较好地解决拼图模式下无级缩放和快速漫游问题。  相似文献   
63.
Berth allocation is essential for efficient terminal utilization in container ports, especially those in Asia. This paper is concerned with a berth allocation problem(BAP) that minimizes the sum of port staying times of ships and that minimizes dissatisfaction of the ships in terms of the berthing order. In general there exist tradeoffs between these objectives. An algorithm is presented to identify noninferior solutions to the BAP. The algorithm is demonstrated with some sample problems and the results indicate the importance of the problem in efficient terminal utilization.  相似文献   
64.
引航控制模型是考虑了人在控制闭环中作用的船舶自动引航模型,它不同于精确控制航迹或者航向的自动舵控制模型,重点在于量化和探索船舶驾引知识和经验.它是港口航道设计和安全评估经常采用的快时模拟的基础.基于模糊推理方法,结合系列内河船队操纵性实测数据与实际操船经验,设计出一种仿真智能的内河顶推船队引航控制模型,并以某顶推船队为原型,进行了仿真试验.结果表明:引航控制建模方法,包括隶属度函数和推理规则的确定能忠实地反映人员操舵控制过程.这种建模方法可为快时模拟论证等工作提供理论和技术支持.  相似文献   
65.
本文介绍了快速傅立叶变换的离散算法,并在此基础上设计程序。设计所用的分析信号由电网电压经互感器得到,所用单片机型号为dsPIC30F4011,安装在APP009实验电路板上。程序设计部分主要包括A/D转换部分及FFT变换部分等。实验中,通过A/D转换进行采样,得到一组离散的采样点,通过快速傅立叶变换(FFT)对采样信号进行频谱分析.实验结果表明该测试仪可以实现对电网的各次谐波进行有效检测。  相似文献   
66.
一次性塑料餐具的大量使用给环境造成越来越大的危害,已引起全社会的关注。本文根据我国国情描述了降解餐具的研究背景、研究现状,并指出降解塑料餐具在技术开发、生产应用等领域的发展方向。  相似文献   
67.
This study aims to explore how factors including charging infrastructure and battery technology associate the way people currently charge their battery electric vehicles, as well as to explore whether good use of battery capacity can be encouraged. Using a stochastic frontier model applied to panel data obtained in a field trial on battery electric vehicle usage in Japan, the remaining charge when mid-trip fast charging begins is treated as a dependent variable. The estimation results obtained using four models, for commercial and private vehicles, respectively, on working and non-working days, show that remaining charge is associated with number of charging stations, familiarity with charging stations, usage of air-conditioning or heater, battery capacity, number of trips, Vehicle Miles of Travel, paid charging. However, the associated factors are not identical for the four models. In general, EVs with high-capacity batteries are initiated at higher remaining charge, and so are the mid-trip fast charging events in the latter period of this trial. The estimation results also show that there are great opportunities to encourage more efficient charging behavior. It appears that the stochastic frontier modeling method is an effective way to model the remaining charge at which fast-charging should be initiated, since it incorporates trip and vehicle characteristics into the estimation process to some extent.  相似文献   
68.
The aeronautical industry is still under expansion in spite of the problems it is facing due to the increase in oil prices, limited capacity, and novel regulations. The expansion trends translate into problems at different locations within an airport system and are more evident when the resources to cope with the demand are limited or are reaching to theirs limits. In the check-in areas they are appreciated as excessive waiting times which in turn are appreciated by the customers as bad service levels. The article presents a novel methodology that combines an evolutionary algorithm and simulation in order to give the best results taking into account not only the mandatory hard and soft rules determined by the internal policies of an airport terminal but also the quality indicators which are very difficult to include using an abstract representation. The evolutionary algorithm is developed to satisfy the different mandatory restrictions for the allocation problem such as minimum and maximum number of check-in desks per flight, load balance in the check-in islands, opening times of check-in desks and other restrictions imposed by the level of service agreement. Once the solutions are obtained, a second evaluation is performed using a simulation model of the terminal that takes into account the stochastic aspects of the problem such as arriving profiles of the passengers, opening times physical configurations of the facility among other with the objective to determine which allocation is the most efficient in real situations in order to maintain the quality indicators at the desired level.  相似文献   
69.
This paper discusses the impact of three freight transport policies aiming to promote railroad intermodal transport in Europe, and examines the case of Belgium as a testing ground. These policies consist in subsidizing intermodal transport operations (such as in Belgium, to stimulate rail transport), internalizing external costs (as recommended by the European Union in order to foster cleaner modes), and adopting a system perspective when optimizing the location of inland intermodal terminals. The study proposes an innovative mixed integer intermodal freight location-allocation model based on hub-location theory and deals with non-linear transport costs in order to replicate economies of distance. Our analysis suggests that subsidizing has a significant impact on the volumes transported by intermodal transport, and, to a lesser extent, that optimizing terminal location increases the competitiveness of intermodal transport. On the other hand, according to our assumptions, internalizing external costs can negatively impact the promotion of intermodality. This finding indicates that innovative last-mile transports are needed in order to reduce the external impacts of drayage operations.  相似文献   
70.
This paper considers a congested bottleneck. A fast lane reserves a more than proportional share of capacity to a designated group of travelers. Travelers are otherwise identical and other travelers can use the reserved capacity when it would otherwise be idle. The paper shows that such a fast lane is always Pareto improving under Nash equilibrium in arrival times at the bottleneck and inelastic demand. It can replicate the arrival schedule and queueing outcomes of a toll that optimally charges a constant toll during part of the demand peak. Within some bounds, the fast lane scheme is still welfare improving when demand is elastic.  相似文献   
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