• 제목/요약/키워드: acoustical study

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공석 시 측정값을 활용한 만석 시 강의실의 음향상태 예측법 (Proposing a simple procedure for predicting the acoustical conditions in occupied classrooms from the measured unoccupied values)

  • 안재영;최영지
    • 산업기술연구
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    • 제41권1호
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    • pp.15-20
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    • 2021
  • This work proposes a simple method to use the added absorption per person values to predict the expected values of the acoustical conditions in occupied classrooms. This method is based on the effects of the values of added absorption per person on the unoccupied total absorption values of the classrooms and on other room acoustical parameters. The total sound absorption in an unoccupied classroom can be calculated from measured reverberation times in the classroom. The expected occupied absorption can be calculated using equation which was obtained in a previous study (Choi, 2017) by fitting a linear regression line to a plot of total occupied absorption versus the corresponding unoccupied total absorption values measured in 12 university classrooms. The ratios of occupied-to-unoccupied sound absorption are used to predict increments in the values of acoustical parameters that result when occupants are added to the rooms.

배플형 흡음 소음기 성능 특성의 실무적 경향 연구 (The study on acoustical properties of dissipative silencers with parallel baffles)

  • 유승국;김영찬;김두훈
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2000년도 춘계학술대회논문집
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    • pp.1681-1686
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    • 2000
  • Absorption silencer is one of the most noise reduction devices and covered a wide range of noise matters. On account of the acoustical properties of absorption silencers depend on variable factor and complex matters, the design of silencers couldn't to be exact in various fields. In this study, we predicted the acoustical properties of absorptive silencers based on measured data and assumed how the acoustical properties is changed following baffle thickness, variable baffle form and open area. Also we recorded the pressure drop at each other. So it may a great help to engineer who install and design a silencer in various fields.

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차실 음향 최적 설계에 관한 연구 (Optimal Design of Acoustical Characteristics of Passenger Compartment)

  • 김정수;강연준
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2003년도 추계학술대회논문집
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    • pp.183-188
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    • 2003
  • This study is to make the fundamentals of sound quality evaluation in regard of acoustical characteristics of passenger compartment. The deviation of frequency response function level within audible frequency is evaluated at receiving point in the research of room acoustics. In this study, frequency response function is the one between speaker and driver's ear positions. The positions of driver and audio speakers are optimized by analysis of acoustic mode of acoustic cavity. The main reflection planes are determined by analysis sound ray path diffused at optimized speaker positions. Finally, designer selects acoustical material by analysis of absorption effect of acoustical materials on the main reflection planes in order to avoid to distortion and fluctuation of frequency response function..

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