The impact of major road developments on the spheres of urban influence of Japanese cities

This study aims to measure the impact of major road developments on the spheres of urban influence of Japanese cities.First, the sphere of urban influence is defined by application of an individual behavior model. The model explains the number of trips to representative cities in regions from the residential place of each individual using the following factors; the attractiveness of cities, the travel time to cities and the individual's free time. Development of major roads shortens the travel time, and this causes the change in the sphere of urban influence. The model we propose has the structure to explain this phenomenon.Second, this method is applied to all of Japan where expressways are now being rapidly constructed and, how they change spheres of urban influence is explained. In the application, as a measure of attractiveness of cities, population, commercial and industrial activity, etc. are considered. From these points of view, the impacts of construction of expressways in Japan are estimated.     

Strategic fleet size planning for maritime refrigerated containers

In the present economic climate, it is often the case that profits can only be improved, or for that matter maintained, by improving efficiency and cutting costs. This is particularly notorious in the shipping business, where it has been seen that the competition is getting tougher among carriers, thus alliances and partnerships are resulting for cost effective services in recent years. In this scenario, effective planning methods are important not only for strategic but also operating tasks, covering their entire transportation systems. Container fleet size planning is an important part of the strategy of any shipping line. This paper addresses the problem of fleet size planning for refrigerated containers, to achieve cost-effective services in a competitive maritime shipping market. An analytical model is first discussed to determine the optimal size of an own dry container fleet. Then, this is extended for an own refrigerated container fleet, which is the case when an extremely unbalanced trade represents one of the major investment decisions to be taken by liner operators. Next, a simulation model is developed for fleet sizing in a more practical situation and, by using this, various scenarios are analysed to determine the most convenient composition of refrigerated fleet between own and leased containers for the transpacific cargo trade.     

前列腺特异性抗原值增高患者前列腺液中白细胞状态的研究

目的研究获取的前列腺特异性抗原(PSA)值增高患者的前列腺液中的白细胞状态。方法112例PSA值增高的患者在行经直肠前列腺穿刺活检前获取前列腺液,并行前列腺液中的白细胞计数。用相关分析和t检验分析白细胞与患者年龄、PSA、前列腺体积等的关系。结果所有患者的前列腺液中白细胞密度加大(平均5.29×106/mL),白细胞总数增高(平均1.58×106)。前列腺液的体积和白细胞总数与前列腺体积呈显著性相关,非前列腺癌患者较前列腺癌患者的前列腺体积和白细胞总数显著增高。结论非前列腺癌患者的PSA值增高可能与前列腺液中的白细胞增高有关。     

Efficient planning of berth allocation for container terminals in Asia

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.     

市郊列车用全封闭式永磁同步电动机

风冷式感应电动机广泛用作铁道车辆的牵引电动机.但它们需要大修进行内部清洁,而且还是噪声的主要来源.为解决这些问题,建议使用全封闭式永磁同步电动机作牵引电动机,它具有与传统的风冷式感应电动机相同的功率-重量比.报告了温升试验、噪声测定和能耗计算的结果.结果表明噪声等级下降10 dB,能耗约降低10%.     

日本N700系列高速列车的发展

中日本铁路公司将于明年在东海道新干线上引进新一代的高速列车，这将为铁路建立新的技术标准奠定基础：同时，这也展现了该公司在过去42年里为提高东海道新干线的运输能力做出不懈努力所取得的最新成果。     

物流网络选址与路径优化问题的模型与启发式解法

以商品从供应商,经过物流中心(或配送中心),配送到最终用户的整个过程中所产生的费用最小化为目标函数,提出了求解供应商的最佳位置与数量、配送中心的最佳位置与数量以及从配送中心到最终用户的最佳配送路径优化问题,建立了问题的数学模型,利用传统启发式算法与模拟退火法开发了问题求解的混合启发式解法,并利用人工生成数据和实例进行了计算验证。对于小规模问题,通过与数理规划软件所求得的最优解进行比较可以看出,所提出的数学模型可以准确地描述此类问题,所提出的混合启发式解法能够在短时间内求解问题,并得到非常接近于最优解的近似解;对于大规模问题,虽然无法求得最优解进行比较,但从实例计算结果来看,所求解也是较好的,因此可以认为所提出的解法是有效和良好的,具有较高的实用价值。     

感应电动机无速度传感器矢量控制在铁道机车车辆传动方面的应用

铁道机车车辆牵引领域中的转矩控制是利用脉冲发生器(PG)来检测牵引感应电动机的转子频率.从提高牵引系统可靠性、降低成本和维修费用以及减小感应电动机尺寸的观点出发,最好不使用PG.为此,一直在研究把无速度传感器控制方法应用于牵引感应电动机的控制,提出了应用无速度传感器的控制策略.文章叙述了铁道机车车辆牵引的新控制方法并出示一些研究试验的结果.