• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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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.

• Speech Sciences
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• v.11 no.1
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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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• v.8 no.2
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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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• v.44 no.8
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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.

• Journal of Environmental Impact Assessment
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• v.22 no.4
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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.

• Journal of Environmental Policy
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• v.8 no.2
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• pp.63-82
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• 2009

Because many people suffer from physical and mental damage caused by the noise created by transportation infrastructure, including road traffic, rail, and aircraft, developed countries have conducted research on predicting and solving the impact to human health from being exposed to transportation noise. Therefore, this study suggests a fundamental plan to assess the health impact of transportation noise on the basis of domestic and foreign prediction results regarding the health impact of transportation noise. The domestic and foreign exposure-response expressions, including the noise index and the health impact indicator of annoyance and sleep disturbance, are compared, and it is found that domestic individuals show a more sensitive response to transportation noise. Based on domestic and foreign research, and a case study regarding the health impact of transportation noise, a fundamental plan to assess the health impact of transportation noise comprises the preparation of objective assessment standards through the improvement of exposure-response models, and the establishment of reduction measures which can improve the quality of the transportation noise environment.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.63 no.3
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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.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.11
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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.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11b
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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.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2003.11a
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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.