• 한국자동차공학회논문집
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• 제4권3호
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• pp.40-49
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• 1996

With the advance of the standard of living, the demand on automobile goes beyond the simple transportion equipment, therefore the interior noise reduction has been the important factor for improvement of the ride quality. Idling noise is a major vehicle characteristic determining occupant comfort. In the present research two approaches for noise source identification based on theory for multi-input system have been investigated. The concept of the frequency response function and the multi-dimensional spectral analysis were used to estimated the spectra of the noise source.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.753-759
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• 2014

In this paper, it is investigated that noise generation mechanism of a rotary compressor using experimental method. The measurement was carried out for primary parameters which influence noise characteristics. By using STFT(short time fourier transform), noise sources of a rotary compressor were identified and vibrating modes that increase the noise are verified. Also, it was studied that the correlation between operating speed and noise. Main factors that affect the variation of noise level were considered by the comparison of the experimental results. In addition, a dynamic characteristic of crank shaft was studied and the critical speed was analyzed.

• 한국자동차공학회논문집
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• 제5권3호
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• pp.171-171
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• 1997

Sound intensity distributions and energy flow in the near field of dipole source system and flat plate were investigated. First, the effectiveness of complex acoustic intensity was proved by using mathmatical and experimental methods in order to indentify noise sources and transmission paths of dipole field which is effected by the presence of neighbouring coherent sources. Next, analytical complex acoustic intensity method was discussed and the characteristics and energy flow of sound induced from the plate are clarified. The velocity of plate obtained from Finite Element Method was used for calculation of complex acoustic intensity in the near field. Finally experimental complex acoustic intensity method was applied to a passenger car. It can be seen that complex acoustic intensity method using both of active and reactive intensity is vital in devising a strategy for the identification and the reduction of vibration and noise.

• 한국자동차공학회논문집
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• 제5권3호
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• pp.159-171
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• 1997

Sound intensity distributions and energy flow in the near field of dipole source system and flat plate were investigated. First, the effectiveness of complex acoustic intensity was proved by using mathmatical and experimental methods in order to inden- tify noise sources and transmission paths of dipole field which is effected by the presence of neighbouring coherent sources. Next, analytical complex acoustic intensity method was discussed and the characteristics and energy flow of sound induced from the plate are clarified. The velocity of plate obtained from Finite Element Method was used for calculation of complex acoustic intensity in the near field. Finally experimental complex acoustic intensity method using both of active and reactive intensity is vital in devising a strategy for the identification and the reduction of vibration and noise.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1996년도 추계학술대회논문집; 한국과학기술회관, 8 Nov. 1996
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• pp.43-49
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• 1996

소음원의 특성을 규명하는 방법론들은 방위각 추정 방법론에 근간을 둔 소음원 위치 탐지 방법과 같이 소음원의 등가 단극음원 크기 및 위치들을 추정하는 기본적인 방법들로부터 보다 많은 계측기기 및 탐촉자와 함께 상당히 정교한 데이타 처리를 수행하여야 하는 인텐시티를 이용한 음장 맵핑(mapping) 홀로그라프를 이용한 관심음장 전체의 3차원 맵핑등 실로 다양하다 할 수 있다. 결국은 가장 많은 탐촉자를 사용하는 측정 시스템이 보다 많은 음장의 정보를 제공하므로서 가장 탁월한 방법론이라 결정할 수 있다. 이것은 특히 탐촉자 자체의 가격이 저렴해져 가는 추세인 점과 소형화하는 추세를 감안하여 봄과 동시에 공간상의 물리적인 의미 즉 파수영역에 대한 보다 폭 넓은 이해를 통한 시간, 공간, 주파수, 파수영역 즉 확대된 차원에서의 음장, 소음에 대한 이해를 갖을 수 있다는 면에서도 가치 있다고 할 수 있다.

• The Journal of the Acoustical Society of Korea
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• 제21권4E호
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• pp.156-163
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• 2002

We apply independent component analysis (ICA) for extracting an optimal basis to the problem of finding efficient features for representing speech signals of a given speaker The speech segments are assumed to be generated by a linear combination of the basis functions, thus the distribution of speech segments of a speaker is modeled by adapting the basis functions so that each source component is statistically independent. The learned basis functions are oriented and localized in both space and frequency, bearing a resemblance to Gabor wavelets. These features are speaker dependent characteristics and to assess their efficiency we performed speaker identification experiments and compared our results with the conventional Fourier-basis. Our results show that the proposed method is more efficient than the conventional Fourier-based features in that they can obtain a higher speaker identification rate.

• 한국해양학회지
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• 제21권2호
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• pp.118-123
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• 1986

流出油는 GC分析에 의한 油指紋法(Oil Fingerprinting Method)으로 流出原因油와 比較分析하여 識別한다. 一般的으로는 GC에 의하여 飽和炭化水素, 黃化合物을 分離分析한다. 그러나, 기름의 成分은 複雜하고 流出된 상태에 따라 成分組成이 변하므로 어느 한 成分의 分析에 의한 識別보다는 여러성분에 대한 多角的인 分析에 의한 識別方法이 要求된다. 本 硏究에서는 原油, 重油中에 含有되 어 있는 多環芳香族 炭化水素를 分離分析하였다. 이들은 比較的 安定하기 때문에 時 化의 영향을 적게 받는다. GC에 의한 多環芳香族 炭化水素 分析은 産油地 判別 및 油種을 識別할 수 있는 油脂紋法의 한 方法이다.

• 한국음향학회지
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• 제21권4호
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• pp.156-156
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• 2002

We apply independent component analysis (ICA) for extracting an optimal basis to the problem of finding efficient features for representing speech signals of a given speaker The speech segments are assumed to be generated by a linear combination of the basis functions, thus the distribution of speech segments of a speaker is modeled by adapting the basis functions so that each source component is statistically independent. The learned basis functions are oriented and localized in both space and frequency, bearing a resemblance to Gabor wavelets. These features are speaker dependent characteristics and to assess their efficiency we performed speaker identification experiments and compared our results with the conventional Fourier-basis. Our results show that the proposed method is more efficient than the conventional Fourier-based features in that they can obtain a higher speaker identification rate.

• 한국소음진동공학회논문집
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• 제24권8호
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• pp.628-635
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• 2014

The procedure to estimate the sources of noise and vibrations in a typical drum-type washing machine was presented. The sources should be identified to predict the radiated noise with computational model of structure. Source identification techniques based on singular decomposition were implemented using the measured signals of accelerometers and microphones. The finite element analysis and indirect boundary element analysis were implemented to predict the structural vibrations and the acoustic pressures at the field points. The predicted results by only structural sources were compared with those by both structural and acoustical sources. It was verified that not only the structural-borne source but also air-borne source should be considered to predict the radiated noise with better accuracy. The contribution analysis with respect to the transfer path was also preformed.

• 응용통계연구
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• 제31권1호
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• pp.1-11
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• 2018

최근 다변량 공정관리는 다양한 응용 분야에서 중요해지고 있는 추세이다. 예를 들어, 제조 산업 분야에서는 다변량 품질특성치를 동시에 모니터링할 필요가 있다. 그러나, 다변량 관리도는 이상신호가 발생한 경우 그 원인이 되는 개별적인 변수를 식별하기가 어렵기 때문에, 실제로는 기대만큼 유용하게 쓰이고 있지 않은 형편이다. 이에 본 논문에서는 새로운 관측치에 대한 개별적인 신뢰구간을 사용하여 이상신호의 원인을 탐지하는 세 가지 방법을 소개하고, 시뮬레이션 연구를 통해 이상신호의 원인이 되는 개별적인 변수를 식별하고 해석하는 데 있어 주의할 점이 무엇인지 살펴보기로 한다.