<Original Paper>Effects of Intervention on Seating for Elderly Wheelchair Users

The purpose of this paper is to report the results of intervention on the fit of seating for elderly wheelchair users who use foot propulsion. The elderly users, who lived in care facilities, were provided with improved wheelchairs for about two months while we investigated the seating posture, independent mobility, and degree of satisfaction during use. The results of the investigation are as follows: (1) Seating pressure for the subjects who used the fitted wheelchair tended to decrease. (2) Independent mobility for the subjects using the fitted wheelchair tended to decrease. On the other hand, cases where the independent mobility improved were also observed. (3) Subjects were satisfied with the comfortable seating of the improved wheelchair. However, the small-sized elderly subjects were dissatisfied with the transfer, the meal action, and the fitted seat

Understanding the contribution of groove resonance to tire-road noise on different surfaces under various operating conditions

Reducing tire-road noise is now becoming more and more important during the tire development process. Tread profile randomization is used to avoid tonal components and reduce groove resonance noise. To better understand the groove resonance contribution to tire-road noise, we performed acoustic measurements on a test bench with two serial tires. We filled the grooves with acoustic foam to highlight the groove resonance’s contribution. We then varied the road surface, the tire load and the driving speed. In the end, we used a multiple linear regression to quantify the interaction between the varying parameters and the groove resonance noise. We show that groove resonance contributes an average of 1.7 dBA to the tire rolling noise of passenger car tires. Groove resonance noise also increases with the driving speed. While the tread pattern and the tire load are responsible for the spectral content of the groove resonance noise, the orientation of the road surface’s texture mainly influences the noise level of the groove resonance. The tire manufacturers should carefully consider these findings when developing noise-optimized patterns. This is especially true for tire approval tests, which take place on tracks and usually have a relatively low texture level that is oriented negatively

Development of a UAV-mounted Light Source for Fluorescence Detector Calibration of the Telescope Array Experiment

ArticleThe Physical Society of Japanjournal articl