We worked on the reduction of Shinkansen wayside noise at higher speeds using two experimental trains, namely "FASTECH360S" (running only on Shinkansen lines) and "FASTECH360Z" (running on both Shinkansen and conventional lines). Both of these feature several new types of equipment for reducing pantograph noise and noise from the lower part of cars, which have the greatest effect on overall noise level in series E2-1000, the newest commercial trains in JR-East. Low-noise pantographs and noise insulation plates were used with the intention of reducing pantograph noise. Sound-absorbing panels were installed to reduce noise emitted from the lower part of cars. We conducted running tests with the FASTECH360 trains to measure wayside noise. The results show that to operate at the same noise levels as current commercial trains (namely series E2 and E3 (coupled) running at 275 km/h), FASTECH360S and FASTECH360Z (coupled) would have to run at approximately 330 km/h, and FASTECH360S (alone) at approximately 340 km/h. We verified that the combination of certain measures for the reduction of pantograph noise and noise from the lower part of cars were rather successful in mitigating Shinkansen wayside noise.

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The key point of the research is to improve the eco-driving performance in a hybrid truck among various drivers. In the previous paper, the investigation relationship between the driver control parameters, driving performance and fuel economy showed a potential to improve fuel economy and reduce the dispersion of fuel economy among various driver model parameters by improving the vehicle longitudinal dynamics. Then a hybrid torque distribution controller with a driving torque feedback compensator improving the driving torque response and the automatic transmission controller considering gear changing speed has been proposed. The simulation studies showed that by using proposed hybrid control system both longitudinal dynamic performance and fuel economy can be improved among various driver model parameters. In this paper, the proposed hybrid control system has been verified by a driving simulator with several real drivers. The result indicates that the driving performance and fuel economy of the HEV among various drivers were improved by using proposed hybrid control system. The detail analysis of influence driving performance on fuel economy among all test drivers clarifying the effectiveness of proposed hybrid controller confirms that, the proposed hybrid controller has improved the e-co driving performance of each driver.

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Although understanding the risk factors with suitable evaluation indices is useful in order to improve the safety of vehicle driving, there is no evaluation index for low-speed vehicles on pedestrian spaces. Because the characteristics of pedestrian spaces as driving environment is different from that of roadway for automobiles, we do not directly use the existing evaluation indices proposed in research field of automobiles. Therefore, we constructed an evaluation index for low-speed vehicles driving on pedestrian spaces. At first, we compared the characteristics of the driving situations of existing indices to that of our target situation, and proposed the evaluation index “Ellipse-Mapped Relative Risk”. Next, we confirmed the characteristics of proposed index by simulation and experiment. From the results of simulation, EMRR’s ability to evaluate the apparent risk in various driving situations was confirmed. On the other hand, from the results of experiment, consistency for the risk perception of the drivers was confirmed. At last, with the proposed evaluation index, a risk effect of pedestrians was partly confirmed as the first step of understanding the risk mechanisms.

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Currently, the minimum allowed longitudinal time separation between two aircraft on oceanic routes is set to 15 minutes. However, to deal with heavy traffic, a decrease to 10 minutes has been under consideration. So far, a major disadvantage of the conventional loss distribution method applied to calculate the risk of collision has been that it cannot guarantee safety in the case of reduced separation minima. In this paper, the loss distribution method is refined to avoid over-estimation by considering the relative speed of two aircraft and appropriate data sampling.

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This paper presents a theoretical study on the directional stability of multi-articulated vehicles with multiple axles. The vehicle dynamics model is derived in the horizontal plane having degrees of freedom of vehicle side-slipping and yawing. For an equal vertical load of each axle as well as an equal cornering coefficient of each wheel of the multiple axles, the equations of motion can be reduced to ones with a single axle and additional terms that are functions of the number of axles and the distances between them. Two types of tractor and double-trailer combinations with multiple axles are examined with regard to straight running stability as well as steering sensitivity in steady-state turning. Non-oscillatory stability incorporating steering sensitivity is analyzed using the stability factor of multiple-axle vehicle combinations. A parameter study of oscillatory stability and steering sensitivity is conducted, and the following conclusions are drawn. (1) The terms on multiple axles are added in the tractor yawing moment and part of the trailer yawing moment. (2) Multiple-axle vehicles differ from single-axle vehicles in non-oscillatory stability and steering sensitivity. (3) A multiple-axle dolly improves oscillatory stability.

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