著者

堀畑 聡 新家 光雄 野崎 隆宏 赤堀 俊和 鈴木 亨 曽根 圭司 庭田 俊一 福田 徳久

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.79, no.803, pp.2240-2249, 2013 (Released:2013-07-25)

参考文献数

6

被引用文献数

1

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Traditionally, the metal mouthpieces of trumpets have been generally made of brass. However, for musicians who suffer from metal allergies, the use of the mouthpiece sometimes lead to inflammation of the lip if they are taking part in a long performance. This problem can be solved by using allergy-free pure titanium (titanium) and its alloys as the material for the mouthpiece. Therefore, a titanium alloy composed of non-toxic and allergy free elements has been designed. However, because their heat conductivity is generally poor, and they contain α phase with its HCP (hexagonal closed packed structure having structure, which restrict slip systems, forming them into suitable shapes can be very difficult. Therefore, precision casting method, where only final finishing was conducted by machining, applied for fabricating the mouthpieces of trumpets. Important considerations for use in musical instruments are the material characteristics and the sound characteristics of mouthpieces made of titanium alloy. Research on the material characteristics of titanium alloy mouthpieces is currently being undertaken. On the other hand, the sound characteristics of mouthpieces made of titanium alloy have not been examined sufficiently. In this study, the sound and the vibration characteristics of two kinds of mouthpieces made of titanium and Ti-Nb was examined. The adaptability of these materials for use in mouthpieces of trumpets was discussed by comparing the sound characteristics of mouthpieces of trumpets made of titanium, Ti-Nb, and brass.

著者

赤堀 俊和 新家 光雄 仲井 正昭 堤 晴美 野崎 隆宏 堀畑 聡 鈴木 亨 曽根 圭司

出版者

一般社団法人 軽金属学会

雑誌

軽金属 (ISSN:04515994)

巻号頁・発行日

vol.58, no.11, pp.604-610, 2008-11-30 (Released:2008-12-30)

参考文献数

13

被引用文献数

1

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Binary titanium alloys containing Nb or Ta, which are allergy-free and non-toxicity elements, were fabricated, and then the possibility of their application to various music instruments made of brass was investigated by the evaluation of corrosion characteristics, elastic modulus-density ratio (E/ρ), resonance frequency (f) and internal friction (Q−1) . The practical models of the mouthpieces of the trumpets made of the binary titanium alloys were also fabricated by precision casting method in order to compare directly with the sound characteristics of those made of brass and commercially pure Ti. The critical current density for the passivation of the Ti–Nb and Ti–Ta system alloys is approximately 40% lower than that of brass and nearly equal to or a little higher than that of commercially pure Ti. The Q−1 of the Ti–Nb and Ti–Ta system alloys with α″ phase drastically increase. The E/ρ and f of the Ti–Nb and Ti–Ta system alloys exhibit a positive relationship. The sound characteristics of practical mouthpieces of trumpets for a bass instrument can be controlled by changing the E/ρ and f of the alloys.

著者

矢野 賢一 大原 瑛一 堀畑 聡 青木 隆明 西本 裕

出版者

The Society of Instrument and Control Engineers

雑誌

計測自動制御学会論文集 (ISSN:04534654)

巻号頁・発行日

vol.45, no.12, pp.638-645, 2009 (Released:2011-11-03)

参考文献数

9

被引用文献数

5 9

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A robot that supports independent living by assisting with eating and other activities which use the operator's own hand would be helpful for people suffering from tremors of the hand or any other body part. The proposed system using adaptive filter estimates tremor frequencies with a time-varying property and individual differences online. In this study, the estimated frequency is used to adjusting the tremor suppression filter which insulates the voluntary motion signal from the sensor signal containing tremor components. These system are integrated into the control system of the Meal-Assist Robot. As a result, the developed system makes it possible for the person with a tremor to manipulate the supporting robot without causing operability to deteriorate and without hazards due to improper operation.

著者

章 忠 井 和章 三宅 哲夫 今村 孝 堀畑 聡

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:03875024)

巻号頁・発行日

vol.74, no.739, pp.642-649, 2008-03-25 (Released:2011-03-04)

参考文献数

10

被引用文献数

1 1

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The direction of a generated sound source can be estimated by humans using the time difference between both ears and the characteristics of the sound. However, it is very difficult to create an estimation system using a computer and two microphones. Aims of this study are the achievement of three dimension sound localization with two microphones. We have developed the sound source direction estimation system, in which the sound source direction can be shown by two angles, the horizontal angle α and the vertical angle, β. The former is presumed from the difference of the arrival time when the sound progresses from the source to right and left ear, and the latter is presumed from spectrum correlation analysis using head related transfer function (HRTF). In this study, we propose a novel sound source direction estimation method, in which the feature difference of two recorded microphone signals is used. As a result, an average correct estimation rate of 96% was obtained in determining the location of 11 kinds of object sounds.