日本音響学会誌
Online ISSN : 2432-2040
Print ISSN : 0369-4232
27 巻, 4 号
選択された号の論文の4件中1~4を表示しています
  • 加川 幸雄
    原稿種別: 本文
    1971 年 27 巻 4 号 p. 201-213
    発行日: 1971/04/10
    公開日: 2017/06/02
    ジャーナル フリー
    Finite element method was originally developed for analysing structures like beams and shells. In a previous paper (26, 3, p. 117-128, 1970), it has been shown that the method can be applied to the vibration problems involving coupled mechanical and electrical systems. This paper develops and adapts this method for the analysis of electromechanical filters of complex shape and construction. The transmission characteristics of the filters can be calculated directly without employing the usual technique of an equivalent electrical circuit. Two examples of analysis are introduced for presentation. In the first one the input and output electrodes are set up on the transducers of a composite vibrator, while in the second two vibrators are coupled by a pair of bars.
  • 江原 史郎
    原稿種別: 本文
    1971 年 27 巻 4 号 p. 214-224
    発行日: 1971/04/10
    公開日: 2017/06/02
    ジャーナル フリー
    This paper describes the statistical properties of spectrum amplitude distribution, the variation constants for sixthoctave bend amplitude distributions and an analysis of frequency bands in which full-band amplitude distribution is preserved. The main results for nine pieces of music are shown on the graphs of spectrum amplitude distributions. They include an average of these distributions weighted by the duration interval of performance, a moving average of mean spectrum amplitude distribution and an emphasized spectrum amplitude distribution. The results of spectrum amplitude distribution are summarized as follows; (1) mean rms spectrum can be approximated by the response frequency characteristics of one stage RC filters with time constants of 530 μ sec at higher frequencies and 1, 600 μsec at lower frequencies, (2) spectrum amplitude distribution has an obvious tendency to change according to the year of composition, and (3) moving-averaged rms spectrum is a good estimate for mean rms spectrum. By other analyses, it is found that (4) the shape of full-band amplitude distribution is preserved in the wider band than about an octave of any frequency a considerable power is contained in that band, and (5) band variation-constants vary with frequency at about two-octave period and are closely related to the key of the music measured, while a linear combination of variation constants in each band makes an almost invariant value with respect to frequency.
  • 小倉 東洋
    原稿種別: 本文
    1971 年 27 巻 4 号 p. 225-230
    発行日: 1971/04/10
    公開日: 2017/06/02
    ジャーナル フリー
  • 城戸 健一
    原稿種別: 本文
    1971 年 27 巻 4 号 p. 231-235
    発行日: 1971/04/10
    公開日: 2017/06/02
    ジャーナル フリー
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