• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.720-725
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• 2016

This study examined how the APU noise of an aircraft influences the work efficiency and stress of airport ramp workers. A survey of airport ramp workers was conducted and the results analyzed. In the demographic analysis, men outnumbered women - accounting for 86% of the survey target - and 80% of the respondents were found to be employees with less than 15 years of work experience. The occupational cluster of the total of 160 respondents included 41 aircraft maintenance workers, 70 ground staff (Cargo, Water and Waste services), 19 ramp coordinators, 18 ramp controllers and 12 catering Service workers. The ground staff were the most prevalent, constituting 44% of the occupational cluster. Regarding the APU noise, 74% of the respondents answered that the environment was "always noisy", while 26% answered that it was "sometimes noisy". 85% answered that they are sensitive to and put under stress by the APU noise, while the majority of the respondents answered that the APU noise degrades their work efficiency. In conclusion, this study examined the effect of APU noise on the work efficiency and stress of airport ramp workers by analyzing the survey data by Regression and Chi-square analysis.

• Journal of Korea Multimedia Society
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• v.18 no.4
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• pp.437-442
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• 2015

Voice activity detection is very important process that voice activity separated form noisy speech signal for speech enhance. Over the past few years, many studies have been made on voice activity detection, but it has poor performance in low signal to noise ratio environment or fickle noise such as car noise. In this paper, it proposed new voice activity detection algorithm using ensemble variance based on wavelet band entropy and soft thresholding method. We conduct a survey in a lot of signal to noise ratio environment of car noise to evaluate performance of the proposed algorithm and confirmed performance of the proposed algorithm.

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.8
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• pp.1309-1314
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• 2008

Seismic data is often contaminated with high-energy, spatially aliased noise, which has proven impractical to attenuate using Fourier techniques. Wavelet filtering, however, has proven capable of attacking several types of localized noise simultaneously regardless of their frequencies. In this study a 2-D stationary wavelet transform is used to decompose seismic data into its wavelet components. A threshold is applied to these coefficients to attenuate high amplitude noise, followed by an inverse transform to reconstruct the seismic trace. The stationary wavelet transform minimizes the phase-shift errors induced by thresholding that occur when the conventional discrete wavelet transform is used.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.8 s.101
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• pp.980-987
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• 2005

It is very difficult to reduce ambient noise level in the downtown. The best method is to improve the sound amenity of the districts, considering concept of soundscape. This study aims to survey the effect of introducing sound and masking to reduce the background noise level. We carried out the evaluating test for 18 introducing sounds varied S/N ratio(-5, 0, +5) in the city riverside. In these test, subjects evaluated the sound environment with five bipolar adjective scales. It was evaluated that introducing sounds improved the sound environment, and that S/N +5 dB was very appropriate to mask the background noise. But the hearing level was suggested to be S/N 0 dB or less.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.607-610
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• 2005

It is very difficult to reduce traffic noise level in the downtown. The best method is to improve the sound amenity of the districts, considering concept of soundscape. ?his study aims to survey the effect of introducing sound and masking to reduce the background noise level. We carried out the evaluating test for 18 introducing sounds varied S/N ratio(-5, 0, +5) in the city riverside. In these test, subjects evaluated the sound environment with five bipolar adjective scales. It was evaluated that introducing sounds improved the sound environment and that S/N + 5dB was very appropriate to mask the background noise. But the hearing level was suggested to be S/N 0 dB or less.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2001.11a
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• pp.14-21
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• 2001

Recently, with the increasing of construction works, large construction equipment are used to reduce the term of work and labor cost in construction field. Therefore, construction equipment noise has caused much annoyance for a number of dweller in nearby construction field and it has become a very serious problem in our living environment. Nevertheless, in our country, adequite guidelines for the construction equipment noise are very deficiency because of the lack of basic data and insufficient research works. From this point of view, this study attempts to survey the characteristics and prediction of SIP piling noise. On the basis of measurement value, we analysed about prediction possibility of SIP piling noise by computer simulation.

• KIEAE Journal
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• v.4 no.3
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• pp.37-44
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• 2004

In this study, foreign and domestic noise criteria on walls, floors, and water supply facilities were reviewed and the results are as follows : regulation can be divided two things, one is on thickness the other is sound insulation performance. Green Building regulation based on the law and this have sound classification systems. Since these regulations are not established in Korea. The noise regulation on water supply-drain facilities and domestic guideline on interior noise level is needed. Foreign regulations are stricter than those of ours. And those has sound classification system for the better acoustic condition of inhabitants'.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.23 no.12
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• pp.1111-1116
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• 2013

In the present study, annoyance caused by diverse construction noises was evaluated through surveys. A survey with a total of 110 construction workers was carried out to investigate annoyance from construction noises at different construction phases. The most effective item of adverse by construction noise was annoyance and the most annoyed construction stage was destruction construction. There were high correlation between work performance and work safety as well as work safety and speech interference. Participant's noise sensitivity were significant between low and high group at work performance, work safety, speech interference.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.10a
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• pp.408-413
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• 2011

In the present study, annoyance caused by diverse construction noises was evaluated through surveys and laboratory experiments. A survey with a total of 110 construction workers was carried out to investigate annoyance from construction noises at different construction phases. The most effective item of adverse by construction noise was annoyance and the most annoyed construction stage was destruction construction. Between work performance and work safety had correlation as well as between work safety and speech interference. Participant's noise sensitivity were significant between low and high group at work performance, work safety, speech interference.

• Journal of the Korean housing association
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• v.12 no.3
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• pp.149-156
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• 2001

Recently, with the increase of income level, many people desire to have agreeable and quiet surrounding. However, construction noise has caused much annoyance for a number of dwellers and workers in nearby construction field. It has become a very serious issue in our living environment. For the accurate evaluation of construction noise with various frequency spectrums and fluctuation characteristics, the evaluation system should reflect not only physical quantities but also the psychological respects of individual persons. With preceding study of psycho-acoustical experiments, this study attempts to survey the classification of adjectives and sound using the method of selected description and intends to get the basic data for establishment of a standard about construction noise.