著者

飯田 明由 小久保 あゆみ 塚本 裕一 本田 拓 横山 博史 貴島 敬 加藤 千幸

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 B編 (ISSN:03875016)

巻号頁・発行日

vol.73, no.732, pp.1637-1646, 2007-08-25 (Released:2011-03-03)

参考文献数

10

被引用文献数

4 1 7

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The aim of this investigation is to understand the generation mechanism of aero-acoustic feedback noise radiated from rear-view mirrors. In order to clarify the relationship between the velocity fluctuation and radiated noise, correlation in terms of aerodynamic noise and velocity fluctuations were measured in a low-noise wind tunnel. The experimental results showed that noise level of the tonal-noise depended on the ratio of the height of the bump to the thickness of the boundary layer. Strong tonal-noise was generated when the height of the bump was almost equal to 40% of the height of the boundary layer. The tonal-noise level also depended on the length between the trailing-edge of the bump and the edge of rear-view mirror. The frequency of the tonal noise can be calculated by modified Rossiter equation. The tonal-noise was disappeared in the case of the bump was placed at separated boundary layer. It revealed that the seed of the tonal noise was small disturbances generated by the bump on the surface of the rear-view mirror.

著者

有川 一 吉田 貫司 久保 あゆみ 坂本 太一 渡邉 孝士郎 今井 一

出版者

日本武道学会

雑誌

武道学研究 (ISSN:02879700)

巻号頁・発行日

vol.53, no.1, pp.1-9, 2020 (Released:2020-09-19)

参考文献数

24

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Research suggests that psychological stress due to competing against opponents of different skill levels affects exercise intensity during kendo gokaku-geiko. However, few studies have clarified the relationship between psychological stress measured using objective indices and exercise intensity. In this study, we measured psychological stress, exercise intensity, and physical activity in players during kendo gokaku-geiko with opponents of different skill levels using objective, non-invasive, simple measures.Six male members of the university kendo team participated in this study. They performed kendo gokaku-geiko for 3 minutes with highly skilled, equivalently skilled, and non-highly skilled opponents. We measured psychological stress indices (salivary amylase activity and autonomic balance [LF/HF]), exercise intensity indices (heart rate [HR], peripheral oxygen saturation [SpO2], rate of perceived exertion [RPE]), and physical activity indices (number of steps and strikes) during keiko.We observed an increasing tendency of salivary amylase activity, HR, RPE, and physical activity indices during keiko with highly, but not with non-highly, skilled opponents. On the other hand, we detected an increasing tendency of LF/HF with both types of opponents.These results suggest that in keiko with highly skilled opponents, the participants experienced tension (i.e. a “fight-or-flight response”) caused by strong pressure and attacks from their opponents; thus, they increased their physical activity and exercise intensity and were likely to experience high stress. On the other hand, in keiko with non-highly skilled opponents, the participants experienced low stress due to a lack of exercise intensity and low physical activity.

著者

久保 あゆみ 芝岡 美枝

出版者

一般社団法人 日本創傷外科学会

雑誌

創傷 (ISSN:1884880X)

巻号頁・発行日

vol.9, no.2, pp.75-80, 2018 (Released:2018-04-01)

参考文献数

18

著者

飯田 明由 小久保 あゆみ 塚本 裕一 本田 拓 横山 博史 貴島 敬 加藤 千幸

出版者

一般社団法人日本機械学会

雑誌

日本機械学會論文集. B編 (ISSN:03875016)

巻号頁・発行日

vol.73, no.732, pp.1637-1646, 2007-08-25

被引用文献数

6

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The aim of this investigation is to understand the generation mechanism of aero-acoustic feedback noise radiated from rear-view mirrors. In order to clarify the relationship between the velocity fluctuation and radiated noise, correlation in terms of aerodynamic noise and velocity fluctuations were measured in a low-noise wind tunnel. The experimental results showed that noise level of the tonal-noise depended on the ratio of the height of the bump to the thickness of the boundary layer. Strong tonal-noise was generated when the height of the bump was almost equal to 40% of the height of the boundary layer. The tonal-noise level also depended on the length between the trailing-edge of the bump and the edge of rear-view mirror. The frequency of the tonal noise can be calculated by modified Rossiter equation. The tonal-noise was disappeared in the case of the bump was placed at separated boundary layer. It revealed that the seed of the tonal noise was small disturbances generated by the bump on the surface of the rear-view mirror.