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.     

Legal regulation of autonomous driving technology: Current conditions and issues in Japan

In Japan, the Road Transport Vehicle Act and the Road Traffic Act were revised after consideration of autonomous driving vehicles operating on public roads. These revisions have considerably reduced the legal obstacles to the operation of autonomous driving vehicles with technology comparable to SAE level 3 on public roads significantly.To consider the remaining legal matters that could arise while autonomous vehicle is running, the newly amended acts are worth examining. In interpreting the purpose and the details included in the amendments, the key concepts for allowing running of the autonomous vehicle such as that of a driver, the operational design domain (ODD) and the related concepts are reviewed.     

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.     

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。