Development of an Active Control Engine Mount System

In an attempt to reduce idling vibration and booming noise in automobile engines, the authors have developed an engine mounting system we call the ACM(Active Control engine Mount) system. Comprising a pair of electromagnetic actuators and hydraulic mounts, the system incorporates an adaptive control strategy based on the synchronized filtered-X LMS (SFX) algorithm. The crank angle pulse signal is detected as the synchronization signal and the force transmitted to the car body through the engine mounts is detected as a residual signal. Application of the ACM system to a vehicle with a transversally mounted four-cylinder engine resulted in significantly reduced idling vibration and booming noise.     

变轨距列车用电动机的开发

我们为变轨距列车研制了2种牵引电动机.一种是直接驱动的永磁同步电动机,另一种是传统的万向轴驱动的异步电动机.对这2种电动机进行了试验,取得了良好的结果.在美国对变轨距列车的高速耐久性运行试验进行了约2年.在运行试验中,电动机没有发生任何故障.运行试验后进行的解体检查也表明电动机没有任何损伤.     

Design system for optimum contra-rotating propellers

A new type of contrarotating propeller (CRP) system has been developed through the cooperative research work of five shipbuilding companies in Japan (Hitachi Zosen Corporation; Kawasaki Heavy Industries, Ltd.; Mitsui Engineering and Shipbuilding Co., Ltd.; NKK Corporation; and Sumitomo Heavy Industries, Ltd.). This paper describes a design system for an optimum CRP, which is one of the numerous outcomes of this work. The optimum design system is composed of three theoretical programs: (1) the design program of the optimum CRP; (2) the steady lifting surface program of the CRP; (3) the unsteady lifting surface program of the CRP. These theoretical programs will be discussed in the first part of the paper, and the design system supported by these theoretical programs will then be verified by comparing calculated and experimental results.Translation of an article that appeared in the Journal of The Society of Naval Architects of Japan, vol. 180 (1996): The original article won the SNAJ prize, which is awarded annually to the best papers selected from the SNAJ Journal, JMST, or other quality journals in the field of naval architecture and ocean engineering.     

日本铁道车辆用超导变压器的开发

介绍了日本铁道车辆用超导变压器的设计研发过程、主要技术参数和定型试验.     

M250系直流货运电动车组的开发

简单介绍了M250系直流货运电动车组的开发情况,阐述了车体、转向架、主电路、辅助电路、制动系统及监视系统等主要结构,并总结了试验结果.     

Course Tracking Control Algorithm Using Visual Information

Automatic steering control algorithm has been proposed, which uses the motion of objects in a visual image (Optical Flow) obtained from an ITV camera looking ahead in the situation without forward vehicles. This algorithm is improved to be applicable to the situation in which the forward tracking course is invisible owing to the interfarence of the forward vehicles. The adjustment of the control parameters against the change in vehicle speed is confirmed by the computer simulation experiments.     

Causality of future and spot grain prices between China and the US: Evidence from soybean and corn markets against the surging import pressure

As the boom of the world grain market phases out, the challenge for Chinese government has gradually moved from retarding grain exports to restraining imports. This study tries to examine the causalities of soybean and corn price movement among the United States (US) future market, Chinese domestic future market and Chinese spot markets. We find that the daily prices of all these three types of grains belong to I(1) series, and there are long-run integrations. Also Chinese soybean future prices adjust more quickly than its spot prices, while Chinese corn future prices adjust slower. This paper finds that the soybean price movement originates from the US future market, then passes through Chinese future market, and finally reaches Chinese spot market, while the corn price movement starts in Chinese spot market, then spreads to the future markets in both China and the US. Finally, this paper also provides some policy implications on how to release the pressure from the grain imports.     

Estimation of CO2 reduction for Japanese domestic container transportation based on mathematical models

This research discusses domestic feeder container transportation connected with international trades in Japan. Optimal round trip courses of container ship fleet from the perspective of CO₂ emission reduction are calculated and analyzed to obtain basic knowledge about CO₂ emission reduction in the container feeder transportation system. Specifically, based on the weekly origin–destination (OD) data at a hub port (Kobe) and other related transportation data, the ship routes are designed by employing a mathematical modeling approach. First, a mixed integer programming model is formulated and solved by using an optimization software that employs branch and bound algorithm. The objective function of the model is to minimize the CO₂ emission subject to necessary (and partially simplified) constraints. The model is then tested on various types of ships with different speed and capacity. Moreover, it is also tested on various waiting times at hub port to investigate the effect in CO₂ emission of the designated fleet. Both the assessment method of container feeder transportation and the transportation’s basic insights in view of CO₂ emission are shown through the analysis.     

Evaluation of an existing bus network using a transit network optimisation model: a case study of the Hiroshima City Bus network

This study evaluates an existing bus network from the perspectives of passengers, operators, and overall system efficiency using the output of a previously developed transportation network optimisation model. This model is formulated as a bi-level optimisation problem with a transit assignment model as the lower problem. The upper problem is also formulated as bi-level optimisation problem to minimise costs for both passengers and operators, making it possible to evaluate the effects of reducing operator cost against passenger cost. A case study based on demand data for Hiroshima City confirms that the current bus network is close to the Pareto front, if the total costs to both passengers and operators are adopted as objective functions. However, the sensitivity analysis with regard to the OD pattern fluctuation indicates that passenger and operator costs in the current network are not always close to the Pareto front. Finally, the results suggests that, regardless of OD pattern fluctuation, reducing operator costs will increase passenger cost and increase inequity in service levels among passengers.