• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.693-695
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• 2007

This study describes the proposed methods for constructing the residential section which satisfies quiet environment and scenery at the same time. For the purpose of achieving this objective, the influences of house arrangement, house skyline change, soundproofing facility installation, etc. on traffic noise environment and scenery are compared using document investigation and computational results.

• 음성과학
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• 제11권1호
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• pp.43-52
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• 2004

This paper concerns an effective dual-channel noise reduction method to increase the performance of speech recognition in a car environment. While various single channel methods have already been developed and dual-channel methods have been studied somewhat, their effectiveness in real environments, such as in cars, has not yet been formally proven in terms of achieving acceptable performance level. Our aim is to remedy the low performance of the single and dual-channel noise reduction methods. This paper proposes an effective dual-channel noise reduction method based on a high-pass filter and front-end processing of the eigendecomposition method. We experimented with a real multi-channel car database and compared the results with respect to the microphones arrangements. From the analysis and results, we show that the enhanced eigendecomposition method combined with high-pass filter indeed significantly improve the speech recognition performance under a dual-channel environment.

• Safety and Health at Work
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• 제8권2호
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• pp.226-230
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• 2017

The performance of sound barriers was evaluated to determine their technical effectiveness and practicality in reducing noise exposures to operating engineers in construction. Commercially purchased sound dampening mats (SDMats) were installed inside three heavy-equipment engine compartments. Sound pressure levels (SPLs) were measured before and after installing the SDMats while the equipment was on idle and full-throttle settings where it normally operates. SPLs inside the heavy-equipment operator cabs were significantly reduced by 5.6-7.6 dBA on the full-throttle setting following installation of the SDMats (p < 0.01). The evaluated engineering control intervention was simple to install, affordable, and substantially reduced the engine noise reaching the heavy-equipment operator, potentially reducing reliance on hearing-protection devices to protect construction workers from noise exposures.

• Nuclear Engineering and Technology
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• 제44권8호
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• pp.977-984
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• 2012

The cross-correlation technique has been widely used for leakage detection of buried pipes, and this technique can be successfully applied when the leakage signal has a high signal-to-noise ratio. In the case of a power plant, the measured leakage signals obtained from the sensors may contain background noise and mechanical noise generated by adjacent machinery. In such a case, the conventional method using the cross-correlation function may fail to estimate the leakage point. In order to enhance the leakage estimation capability of a buried pipe in a noisy environment, an improved cross-correlation technique is proposed. It uses a noise rejection technique in the frequency domain to effectively eliminate the tonal noise due to rotating machinery. Experiments were carried out to verify the validity of the proposed method. The results show that even in a tonal noisy environment, the proposed method can provide more reliable means for estimating the time delay of the leakage signals.

• 환경영향평가
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• 제22권4호
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• pp.361-367
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• 2013

Noise and vibration occurs during construction intermittently, but with the most arise complaints. There is a need to efficiently manage the construction noise and vibration problems because in case a residential facility that requires calmness around the construction site adversely affects the living conditions of nearby residents. The ministry of environment has mandating the installation of soundproofing facilities for the management of construction noise. In order to enforce a particular construction, the mandatory install with soundproofing facilities before the start of construction, and after construction. However, Installation guide of soundproofing facilities for construction sites were not considered affected areas by noise and there is no provision of performance evaluation for soundproofing facilities. In this study, investigated the status and problems of the installation guide for soundproofing facilities in construction sites, we propose an efficient installation guide of soundproofing facilities for the reduction construction noise.

• 환경정책연구
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• 제8권2호
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• pp.63-82
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• 2009

도로, 철도, 공항을 포함하는 교통시설에 의한 교통소음으로 인하여 많은 사람들이 신체적 및 정신적인 피해를 받고 있는 가운데 선진국의 경우 교통소음에 노출된 인체 건강의 위험성을 인지하고 그것을 해결하기 위한 많은 연구가 수행되고 있다. 이러한 연구흐름에 따라 본 연구에서는 교통소음의 건강영향에 대한 국내외 연구결과를 바탕으로 하여 국내 교통소음에 의한 건강위해성을 평가할 수 있는 기본적인 방안을 모색해 보고자 한다. 교통소음의 건강영향에 대한 평가방법 중에서 많은 연구가 진행되고 있는 교통소음에 의한 성가심 및 수면방해 연구는 교통소음의 측정자료 및 설문조사결과를 바탕으로 소음지표에 대한 불쾌감 및 수면방해 호소비율의 관계를 보여주고 있다. 이에 대한 국내외의 노출-반응 예측결과를 비교해 보면 우리나라 사람들이 다른 나라 사람들보다 교통소음에 대해 대체로 더 높은 소음성 불쾌감 및 수면방해를 호소하는 것을 알 수 있다. 교통소음의 건강영향에 대한 연구결과 및 외국의 사례를 바탕으로 교통소음의 건강위해성을 평가할 수 있는 기본적인 방안을 제시하였는데 그에 대한 내용은 국내 교통소음 건강영향 예측모델의 개선을 통한 객관적인 평가기준 마련과 아울러 교통소음에 대한 사람들의 인식정도나 소음환경의 질을 향상시킬 수 있는 저감방안 마련을 포함한다.

• 전기학회논문지P
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• 제63권3호
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• pp.157-162
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• 2014

The active noise control(ANC) method for noise problems solution generally uses filtered-X LMS algorithms. However, Filtered-X LMS algorithms were mainly used but these had a limitation that had to measure a transfer function of secondary noise path. However, newly proposed correlation-LMS algorithms have slightly much calculation and are minutely behind performance, these have a advantage not in measuring transfer function onerously so that we can easily adapt these in real time. Thus Co-LMS algorithm was developed to improve the real-time implementation performance under the variable input noise such as road noise environment. In this paper, the performance of the Co-LMS is presented in comparison with that of the Filtered-X LMS algorithm. Simulation results show that active noise control using Co-LMS have slightly much calculation and are minutely behind performance, these have a advantage not in measuring transfer function onerously so that we can easily adapt these in real time.

• 한국소음진동공학회논문집
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• 제24권11호
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• pp.854-860
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• 2014

Workers engaged in car inspection works have been exposed to many occupational hazards including noise, particulate matter, and volatile organic substances. Noise-induced hearing loss(NIHL) is one of the leading health hazards among Korean workers. The aim of this study is to evaluate the noise levels in several car inspection shops by introducing the evaluation methods of KMOEL/OSHA and ACGIH. Six sites in central area of Korea were selected to monitor the noise levels of workers by personal and area sampling methods for two consecutive days in spring, summer, fall and winter seasons. Dosimeters have been used for this noise monitoring program. Obtained noise levels by the evaluation method according to KMOEL/OSHA are the range of 50.2~88.2 dB(A), these are lower than KOEL/OSHA standards level of 90 dB(A). But highest noise by ACGIH's evaluation methodology is recorded 92.3 dB(A) and is greater than NIHL standard level of 85 dB(A). So that many workers may be exposed to the dangerous noise environment. The higher the car inspection loads daily, the higher the noise levels in the sites. Seasonal fluctuation of noise levels at the process might give monitoring results with high variations. Area noise levels showed higher than those of personal sampling, which illustrate some high noise spots in the car inspection areas.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계 학술대회논문집(수송기계편)
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• pp.35-38
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• 2005

It is widely recognized that train Is one of the most efficient and convenient ways for passenger and freight transportation. However, the environmental noise problem is occurred with the construction and service of train. The noise problems caused by train prevent people from living in a silent environment. Furthermore, this problem is related with the right to preserve one's environment. The objectives of this research are train noise measurement and analysis which might be a base-study for prediction of train noise. This paper mainly deals with the noise of the 'Semaul' train. The train noise shows distinct characteristics according to the variation of height and distance. Furthermore, the database and its interface program are developed for systematic analysis and future research.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2003년도 정기총회 및 추계학술대회
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• pp.95-100
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• 2003

The purpose of this study is to evaluate the noise environment of one-room type multi-family housing around the campus. The field measurements on equivalent noise level of indoor and outdoor were carried out in 6 subject house units during the 26th${\sim}$28th of November 2002. The results are as follows. 1) Outdoor noise levels of 6 subject buildings were distributed 52.8${\sim}$65.3dB(A) and were inappropriate to the standard for environmental noise, 55dB(A). 2) Indoor noise level of 6 subject house units were measured 27.5${\sim}$63.5dB(A). These values were higher than the indoor noise standard (40dB(A)) except subject house D(average 37.6dB(A)). 3) It was found that the differences of indoor noise levels between subject house units were caused by resident's living factor, characteristics of window, and existence of balcony.