• 제목/요약/키워드: 진동음

검색결과 818건 처리시간 0.03초

Hollow cathode discharge에서 자발적 진동의 광검류 신호 측정 (Observation of spontaneous oscillation of optogalvanic signal in a hollow cathode discharge)

  • 이준회
    • 한국진공학회지
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    • 제12권1호
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    • pp.51-54
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    • 2003
  • 아르곤 방전 기체의 음 글로우 영역에서 자발적 직동의 광검류 신호를 관찰하였다. 자발적 진동의 광검규 신호는 3 mA 보다 낮은 땅선 전류에서 나타난다. 준안정 준위의 인자 밀도 변화와 1s-2p 전이의 방출 세기를 동시에 측정한 결과, 자발적 진동 신호를 발생시키는 메커니즘 중의 한 가지는 느린 전자의 충돌에 의한 준안정 준위 원자의 단계적 이온화이다.

국악 피리의 규격화 (Standardization of the Peelee)

  • 이성수
    • 한국음향학회지
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    • 제20권6호
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    • pp.3-8
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    • 2001
  • 악학궤범에 명시된 삼분손익 법에 따라 음향학적으로 해석한 진동수비와 음정관계를 현행 국악에서 연주되고 있는 황종음 269Hz에 맞추어 12음율의 진동수를 계산하였고, 계산된 각율음의 진동수의 음을 취법의 기교없이 쉽게 낼 수 있는 규격화된 피리를 제작하였다. 규격화된 피리를 자연스럽게 연주한 결과 표준진동수에 잘 일치하였다.

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수음실 내 구조체의 진동량 계측을 통한 바닥충격음레벨 예측 (Prediction of Floor Impact Sound by Measuring the Vibration Acceleration Level on the Interior Structures of Receiving Room in Apartment Buildings)

  • 김명준;김흥식;김하근
    • 한국소음진동공학회논문집
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    • 제13권1호
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    • pp.3-9
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    • 2003
  • In an apartment building, the impact sound from upstairs has been regarded as a main source of noise causing discontentment among occupants. To set the optimum design for sound insulation. it is nesessary to suggest the useful tools or technique that predict the floor impact sound. The purpose of this study is to investigate the applicability of the theory of sound radiation. We measured the vibration acceleration levels on the interior structures and predicted the sound pressure level of the room by using them. The result show that the predicted value, in general, were in good agreement with the measured values within 5∼10% in error rate.

표면연소기의 저주파 연소진동음의 특성 (Characteristics of Low-Frequency Combustion-driven Oscillation in a Surface Burner)

  • 한희갑;이근희;권영필
    • 소음진동
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    • 제10권6호
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    • pp.991-997
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    • 2000
  • The objective of this study is to examine the onset condition and the frequency characteristics of the low-frequency combustion oscillation in a surface burner. For this purpose, extensive parametric studies have been performed experimentally and the effects of size of each section, the equivalence ratio, and the entrance velocity on oscillatory behavior explored. The experimental results were discussed in comparison with the other combustors associated tilth the low-frequency combustion oscillation. The combustion mode is driven at high combustion rate by the lift of unstable flame near the lower limit of the combustible equivalence ratio. The oscillation frequency is dependent not on the burner geometry but on the equivalence ratio and the combustion load. Low-frequency combustion mode was formed to be divided into two different modes, named C1 and C2 respectively. Two modes occurred individually, simultaneously or transitionally according to the equivalence ratio and combustion load. The characteristics of low-frequency oscillation is different from each other depending on the type of combustors. The surface burner has also its own characteristics of low -frequency oscillation.

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슬래브 진동모드의 바닥충격음 기여특성에 관한 연구 (Contribution of the Mode Vibration to Heavy Weight Floor Impact Noise)

  • 황재승;박홍근;문대호
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2014년도 추계학술대회 논문집
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    • pp.159-160
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    • 2014
  • The floor impact noise arising between upper and lower households in residential houses has been known as one of major causes worsening residential environment and still led to serious social troubles in a residential community. It is known that the heavy weight floor impact noise is induced by flexural vibration modes in the relatively lower frequency ranges. In this study, a procedure is examined to evaluate the relations between the vibration modes and the corresponding noise of the slab. In the process, for simplicity of the numerical analysis, it is assumed that the slab is simply supported plate-like structure and the acoustic mode formed in the lower room by acoustic boundary conditions is ignored.

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바닥충격음에서의 천장구조에 따른 진동절연 효과 (Vibration isolation effect of floor impact sound by ceiling structure)

  • 이성호;정갑철;정진연
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2004년도 추계학술대회논문집
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    • pp.257-260
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    • 2004
  • This study aims to evaluate factors of ceiling structure influencing to the floor impact sound. For this reasons, we measured the vibration of ceiling and the floor impact sound by ceiling structure. The main results from this study are that ceiling structure makes worse to non-ceiling structure for an effect of air layer in heavy-weight floor impact sound. But it has an effect on light-weight floor impact sound about $2\sim8dB$.

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