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.     

Characteristics of low-frequency motions of ships moored inside ports and harbors on the basis of field observations

In order to understand characteristics of low-frequency motions of ships moored inside ports and harbors, analysis on actual cargo handling logbook of stevedoring services company, including events of interruption of cargo handling, and countermeasure for ship mooring problems are investigated by field observations at two ports and numerical simulation on moored ship motions. First model port concerns with interruption of cargo handling due to the low-frequency motions. Second model port relates to a resonant effect of long-period waves or harbor oscillations, and its countermeasure by mooring system. From the investigation, it is confirmed that the low-frequency motions of ships are induced by a resonance between surge motions and long-period waves or harbor oscillations and an asymmetry in the mooring system, and affect safe ship mooring and operation efficiency of cargo handling in ports and harbors significantly.     

日本铁路提高既有线车辆服务设施水平

JR东海客运公司既有线上运行的车辆都是从旧国铁时代继承下来的,历经25年的运用已变得老化、陈旧.JR民营化以后,公司将这些车辆都替换成了采用最新技术的新型车辆,提高了旅客乘车的舒适性.截至2004年,投入的客运电动车组、内燃动车组占公司车辆保有量的60%左右.     

High-resolution synthetic monitoring by a 4-dimensional variational data assimilation system in the northwestern North Pacific

A data assimilation system is applied to the integrated monitoring of oceanic states in the northwestern North Pacific by combining a high resolution ocean general circulation model with an adjoint method. A comparison of assimilation results with observations shows that the system is better able to represent synoptic features of ocean circulation than do models or data alone. Furthermore, meso-scale features associated with frontal structures and eddies, which are often seen in the Kuroshio and Oyashio extension regions and the Sea of Japan, are better defined in the assimilation results. These features suggest that our 4D-VAR high-resolution data assimilation system is capable of providing time series data which satisfy the model physics and fit the observations, and hence the ocean state derived from our system has greater information content than that obtained from earlier methods.     

Social change and future transport policy in the Japanese context

Despite bringing many external benefits, economic growth has not solved all problems. In Japan today two problems seem to stand out: an aging population and the need to protect the population from natural disasters. The first problem has long been noted but the population is aging so fast that society seems incapable of adjusting properly to the new situation.