著者

吉田 準史 川越 伸幸 河村 智博

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C編 (ISSN:18848354)

巻号頁・発行日

vol.78, no.792, pp.2837-2847, 2012 (Released:2012-08-25)

参考文献数

12

被引用文献数

2

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Bicycle is a popular vehicle for general public because of the low price and the easy maintenance, and will be more importance vehicle by the low environmental loading in the future. Improvement of bicycle ride comfort is one of important factors to increase the popularity. In this study, subjective evaluation test and reduction of bicycle vibration were performed to improve it. In the subjective evaluation, low frequency seat vibration was found to affect the ride comfort very much. Subsequently, transfer path analysis (TPA) and hammering test were performed to obtain vibration characteristic of the bicycle for reduction of the seat vibration. Through TPA, rear frame of the bicycle was found to have high influence to seat vibration than that of front side and the vibration behavior was obtained by modal analysis. For reduction of the seat vibration, a spring was inserted to the front of the seat and steel plates were attached to rear frame to increase the stiffness. As a result, the acceleration level at running condition was decreased about 10 dB by the modification, and the ride comfort was improved so much.

著者

フレディアント 梶山 拓也 吉田 準史

出版者

一般社団法人 日本機械学会

雑誌

Dynamics & Design Conference

巻号頁・発行日

vol.2019, 2019

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<p>Vibration reduction of vehicle is essential to improve the ride comfort. For evaluating the ride comfort, the vehicle vibration is occasionally analyzed in time domain. In this study, we propose a method to obtain the high contributing vehicle body vibration behavior deteriorating the ride comfort at a transient condition in time domain. We considered and applied two methods to realize the time domain analytical method. In the first method, we applied principal component (PC) analysis to the time domain vibration acceleration signals of the multiple body points at the transient condition to obtain the important vibration behavior. In the second method, we applied the PC analysis to the frequency domain signals and re-generated time domain signal by inverse FFT (IFFT). Through a simple vehicle vibration test at a transient condition and the comparison of the result, both methods were found to have ability to extract the high contributing body behavior at the transient condition but the second method utilizing IFFT was clarified to be more useful and accurate method.</p>

著者

井上 一博 フレディ アント 吉田 準史

出版者

一般社団法人 日本機械学会

雑誌

年次大会

巻号頁・発行日

vol.2020, 2020

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<p>In this study, we considered a method to extract a hammering sound in noise environment by removing the noise component using noise transfer function for carrying out correct inspection of the target construction. In the first experiment, hammering test was performed using two tiles (defective and normal tiles) with or without loud white noise from a speaker. Through the proposed method using two microphones (single response and reference microphones), the hammering sound could be extracted well as the sound without noise. Subsequently, another hammering test was carried out when a drone was operated as an instance of the driving noise. However, the method using two microphones could not extract the hammering sound accurately. Then, the number of the reference microphone was increased from one to four to catch the generated noise of each rotating blade. As the result, the hammering sound difference between normal and defective tiles could be grasped better.</p>

著者

中野 宏二郎 橋本 修宏 吉田 準史

出版者

一般社団法人 日本機械学会

雑誌

シンポジウム: スポーツ・アンド・ヒューマン・ダイナミクス講演論文集

巻号頁・発行日

vol.2016, pp.C-26, 2016

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<p>In this paper, we investigated energy distribution of a sports bicycle for evaluating the acceleration performance quantitatively. As the input force for measurement of the performance, constant weight was put on one side pedal of the bicycle positioned on a running roller, and the rotational speed of the wheel was measured under various conditions. The acceleration performance was then calculated by dividing the increased rotating rolling energy by the input energy. The result shows that almost 60% of the input energy was used for the acceleration of the bicycle. In addition, we also investigated influence of the wheel weight (moment of inertia) and air pressure of the tire on the performance. As the results, the performance was increased about 5% by the 30% reduction of the inertia. On the other hand, the performance was observed to decrease about 4% by the 30% reduction of the tire pressure. From these results, we could obtain the influence of the wheel and the tire characteristics on the acceleration performance of the sports bicycle quantitatively.</p>

著者

吉田 準史

出版者

一般社団法人 映像情報メディア学会

雑誌

映像情報メディア学会誌 (ISSN:13426907)

巻号頁・発行日

vol.69, no.7, pp.J221-J226, 2015 (Released:2015-06-25)

参考文献数

13

被引用文献数

1

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本研究では,自動車の外装デザインが,自動車加速中の車内音評価に与える影響について調査を行った.実験では,ヘッドホンから再生される加速音の大きさ,高級感,スポーティ感に関する音質評価を行う際,音単独提示の場合,音と外装デザインを提示した場合それぞれで音質評価を行った.その結果,音の大きさ評価や高級感評価については,外装デザインの有無に関わらず,音の評価傾向に大きな変化は見られなかった.一方で,音のスポーティ感評価においては,外装デザインに対する印象の違いによって,音の評価傾向が有意に変化する傾向が見られた.さらに,その外装デザインがおよぼす音のスポーティ感評価への影響を分析した結果,外装デザインの印象が音のスポーティ感評価に4割程度寄与していることも明らかになった.

著者

吉田 準史 長谷川 光司 春日 正男

出版者

一般社団法人映像情報メディア学会

雑誌

映像情報メディア学会技術報告 (ISSN:13426893)

巻号頁・発行日

vol.32, no.21, pp.9-12, 2008-05-26

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本研究では,ゲームコンテンツの評価に適した用語を選定することを目的に,ゲーム雑誌およびユーザアンケートから数十種類の評価用語を抽出した.さらに20種類のゲームを実際に被験者にプレイさせ,各用語についての当てはまり具合を回答する実験を行った.実験結果に対し,分散分析,クラスタ分析などの統計的な処理を施すことにより,ゲームコンテンツの評価に相応しい用語として「革新的な」,「リアルな」,「幻想的な」,「大勢で楽しめる」,「待ち時間の多い」,「コミカルな」という6種類の評価用語が最終的に選定された.