• Title/Summary/Keyword: 음향학

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A Study for Reducing the Acoustic Cross Talk Level in an Array Type Piezoelectric Ultrasonic Transducer Using Acoustic Wells (음향 벽을 이용한 배열형 압전형 초음파 변환기의 음향 간섭 수준 감소를 위한 연구)

  • 김영신;노용래
    • The Journal of the Acoustical Society of Korea
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    • v.22 no.3
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    • pp.208-216
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    • 2003
  • In one dimensional linear array type piezoelectric ultrasonic transducers widely used for medical diagnosis, the acoustic cross talk caused by the structural acoustic coupling between the adjacent piezoelectric elements reduces significantly their performance. In the study, we have proposed an acoustic wall to reduce the acoustic cross talk by wave propagation through the surface the transducer which can not be prevented by conventional kerf and have analyzed using a finite element method the acoustic cross talk level with respect to the shape, size and materials of the acoustic wall mounted on a convex one dimensional piezoelectric ultrasonic transducer. We expect that the simulated results provide us with a valuable information to make an optimized design of the way type ultrasonic transducer minimizing the acoustic cross talk level.

Thermoacoustic Refrigerating System, Part I : Acoustic Analysis and Design Procedure (열음향 냉장시스템 (I) : 음향학적 해석 및 설계)

  • Hah, Zae-Gyoo;Ahn, Chul-Yong;Sung, Keong-Mo
    • The Journal of the Acoustical Society of Korea
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    • v.14 no.6
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    • pp.5-12
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    • 1995
  • In this paper, acoustic analysis of thermoacoustic refrigerating system was given and the design procedure meeting the specifications was presented. The thermoacoustic refrigerator transforms the sound wave energy into the thermal energy via adiabatic process of inert gas. The system is composed of mainly three parts ; the acoustic motor utilizing loudspeaker the stack of plate for thermal transport and the resonator to form the standing wave. Based upon the acoustic analysis, resonator dimension and stack position and size were decided, and the entire refrigerating system was designed to the given specification. Also the mechanical Impedance of the designed resonator was obtained by simulation.

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An Analysis on Audio Quality Deterioration of Acoustic OFDM (음향 OFDM의 음질 저하 원인 분석)

  • Cho, Ki-Ho;Yu, Hwan-Sik;Chang, Jun-Hyuck;Kim, Nam-Soo
    • The Journal of the Acoustical Society of Korea
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    • v.28 no.2
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    • pp.107-111
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    • 2009
  • Acoustic OFDM is used for audible frequency band acoustic communication which employs loudspeaker as transmitter and microphone as the receiver antenna. Since acoustic OFDM can transmit about 1 kbps using 1600 Hz band. acoustic OFDM signal is inserted into the audio signal like music or speech, However. audio quality deteriorates definitely during the inserting process. This paper introduces a reason for audio quality deterioration and discuss how to reduce this phenomenon.

A Study on Aeroacoustics and Its Applications (공력소음에 대한 연구 및 적용)

  • 이덕주;유기완
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1997.04a
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    • pp.573-580
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    • 1997
  • 본 고에서는 공력음향학에 대한 여러 분야 중에서 최근 국내에서 관심 있게 연구되어온 분야에 대하여 그 연구 내용과 연구 방법 등을 소개하고자 한다. 먼저 전형적인 유체의 소음원에 대해서 설명하고, 이에 대한 수치적 해석방법과 무향풍동을 이용한 실험, 그리고 본 음향학 이론에 대한 응용 사례들에 대해서 간략히 소개하고자 한다.

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