日本音響学会誌
Online ISSN : 2432-2040
Print ISSN : 0369-4232
39 巻, 1 号
選択された号の論文の12件中1~12を表示しています
  • 安田 力
    原稿種別: 本文
    1982 年 39 巻 1 号 p. 1-
    発行日: 1982/12/25
    公開日: 2017/06/02
    ジャーナル フリー
  • 安田 力
    原稿種別: 本文
    1982 年 39 巻 1 号 p. 2-3
    発行日: 1982/12/25
    公開日: 2017/06/02
    ジャーナル フリー
  • 甲田 寿男, 三留 秀人, 柴田 周治
    原稿種別: 本文
    1982 年 39 巻 1 号 p. 4-10
    発行日: 1982/12/25
    公開日: 2017/06/02
    ジャーナル フリー
    An ultrasonic tracking subsystem, utilizing a frequency modulated wave, has been developed for use in an ultrasonic control system of access to the submerged object. The principle of the subsystem is based on the modified ultra-short base line method, that is, the measurement of the incident angle of the frequency modulated wave to the receiving array is accomplished by detecting the phase difference between the sinusoidal waves of low frequency demodulated from the received signals of high frequency. Initial studies and laboratory experiments in air indicate an accuracy of about±1^.in turning the array to the direction of the source.
  • 大島 俊之, 能町 純雄
    原稿種別: 本文
    1982 年 39 巻 1 号 p. 11-18
    発行日: 1982/12/25
    公開日: 2017/06/02
    ジャーナル フリー
    Test results on an actual bridge due to a moving truck are measured and analyzed in this paper. The spectrum analyses of the acceleration wave of the bridge vibration and the sound radiating from its surface are done and they are in a good agreement of the peak frequencies to each other. Dynamic response analysis of the bridge forced by a travelling vehicle, is handled by means of the folded plate theory, and lastly the SPL of the low frequency range is formulated from the particle velocity equation corresponding to bridge and moving vehicle system. The envelope curve of the peak of theoretical SPL values may have a good agreement to the experimental ones. In the numerical calculation, the power spectrum density of the sound and the distributions of the sound in the crosswise direction of the bridge, truss bridge and box girder bridge, are obtained. The power spectrum density of the sound obtained by the effective elementary beam theory are compared with the one given by the folded plate theory and they have a good agreement in the low frequency range.
  • 黒岩 和治
    原稿種別: 本文
    1982 年 39 巻 1 号 p. 19-29
    発行日: 1982/12/25
    公開日: 2017/06/02
    ジャーナル フリー
    This paper describes a method for displaying the sound pressure complex reflection coefficient Γ of the acoustic panel as a vector directly on the cathode-ray tube in real time by using a correlation technique, and its application to a direct view type measurement of the acoustic properties such as sound absorption coefficient α, acoustic resistance R, acoustic reactance Χ, and absolute value|Γ|and phaseφof Γ. In this method, a cross correlation function between source and receiver signals through a narrow band-pass filter which becomes equivalently a sinusoidal sound wave of time delay is used. And, it is realized to display a vector of Γ in real time by extracting the real part|Γ|cosφand the imaginary part|Γ|sinφof Γ directly from the compound sound wave close to the acoustic panel measured by a correlator using a M-sequence signal and by feeding these two analog values to the vertical and horizontal terminals of the cathode-ray tube. Therefore, it is possible to read each of acoustic properties through complex reflection coefficient chart, sound absorption coefficient chart and Smith chart put on the vector. Experiments in the case of the normal incidence are carried out. Comparing with standing wave method, the validity of this method is shown. But, it is not yet about the case of the oblique incidence.
  • 浮貝 雅裕, 高 遠, 三井田 惇郎
    原稿種別: 本文
    1982 年 39 巻 1 号 p. 30-35
    発行日: 1982/12/25
    公開日: 2017/06/02
    ジャーナル フリー
    In this paper, an analytical technique for calculating the amplitude of reflected sound wave from a cylindrical target of finite length for its slightly oblique incidendce is described. This theory is treated on the assumption that a receiver is located separately from a transmitter. The formulas for the reflectivity are derived approximately under certain geometrical restrictions. The reflectivity is termed as the "directional sound reflectivity of the cylindrical target, "which is defined as the ratio of a reflectional sound pressure from a target to a calculated one which is treated due to the theory of geometrical optics. To verify the validity of the approach, some experiments are performed in air at the frequency of 39. 80 kHz. Experimental results show good agreement between the calculated and the measured values and this confirms the usefulness of the present technique to calculate the reflection of sound waves from a cylindrical target.
  • 黒岩 和治
    原稿種別: 本文
    1982 年 39 巻 1 号 p. 36-44
    発行日: 1982/12/25
    公開日: 2017/06/02
    ジャーナル フリー
    This paper describes a method for separating in real time each of progressive and retrogressive spatial sound waves directly from the reflective sound field by using a correlation method. A spatial sound wave implies a spatially distributed sound pressure oscilation, that is, a sound wave group which travels backward and forward between the sound source and the reflector as time elapses. And, it can be equivalently expressed and measured in the form of a correlation function obtained from the sound source and receiver signals in the case of scanning the receiver position(variable)and fixing time delay(parameter). In order to realize the real time separation, the simultaneous scanning both of time delay and receiver position is proposed. Each of progressive and retrogressive spatial sound waves is extracted by scanning time delay with positive and negative time delay ratio respectively, together with scanning receiver position with constant moving velocity. And, their travelling distances are decided proportional to the initial time delay. Some experiments based on the theory are carried out. Then, considering about the sound waves concerning travelling distance and direction, attenuation by distance and wavelength, it is shown that the theory and procedure of the method for separating is valid.
  • 佐久間 貞臣, 上羽 貞行, 森 栄司
    原稿種別: 本文
    1982 年 39 巻 1 号 p. 45-51
    発行日: 1982/12/25
    公開日: 2017/06/02
    ジャーナル フリー
    By using optical heterodyne technique, vertical vibration velocity distributions along radial direction in disk or bevelled disk transducers of Pb(Zr・Ti)O_3 are successfully measured together with their relative vibration phases referring to applied driving signals. They are essential to calculate their volume velocity or directional patterns. The experiment is carried out changing the diameter to thickness ratio from2to12. Their frequency spectra(frequency range:1-700kHz)are also measured to be compared with the vibration velocity distributions. The obtained velocity distributions and frequency spectra show that two groups of radial vibration coupling with the thickness extensional vibration obviously exist in disk vibrations. These two groups are analytically confirmed by finding out the corresponding boundary conditions. And the relations among the diameter to thickness ratio, frequency spectra and vibration modes of disk-type piezoelectric ceramic transducer are clarified.
  • 中嶋 鴻毅, 角所 収
    原稿種別: 本文
    1982 年 39 巻 1 号 p. 52-53
    発行日: 1982/12/25
    公開日: 2017/06/02
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  • 伊東 孝久
    原稿種別: 本文
    1982 年 39 巻 1 号 p. 54-60
    発行日: 1982/12/25
    公開日: 2017/06/02
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  • 川崎 春子
    原稿種別: 本文
    1982 年 39 巻 1 号 p. 61-64
    発行日: 1982/12/25
    公開日: 2017/06/02
    ジャーナル フリー
  • 城戸 健一
    原稿種別: 本文
    1982 年 39 巻 1 号 p. 65-69
    発行日: 1982/12/25
    公開日: 2017/06/02
    ジャーナル フリー
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