• 수산해양기술연구
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• 제53권1호
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• pp.19-40
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• 2017

A scientific and objective sound exposure criterion for underwater sound damage on fish has been required since there has been many disputes between an underwater sound maker and a fish damage receiver. The existing criteria are still incomplete scientifically owing to a degree of variability of underwater sounds, diversity of fish hearing sensitivity and damage types, etc. This study reviews existing studies on a hearing mechanism of fish species, manmade underwater sound characteristics and sound exposure assessment parameters, and recent sound exposure criteria. A governing equation for damage coverage estimation and damage coverage dependency on sound source level, ambient noise and transmission loss are also reviewed and interpreted based on sound exposure environments. The foreign and Korean (National Environmental Dispute Medication Commission) criteria are reviewed and compared based on scientific aspects. In addition, the deficit and limit of Korean criteria are presented. The objective of this study is to give a direction for related researches and legislation of sound exposure criteria on fish.

• 동력기계공학회지
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• 제3권3호
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• pp.97-103
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• 1999

As the noise of ship engine room is too loud, the engineer who works in a ship engine-room has the trouble of hearing. In this paper deals the investigation of the noise of ship engine room and cabins with the internationally allowable noise exposure level and noise exposure time. Recently, the problem of engine-room noise is more serious because of shipowner wants to make small number and larger size of cylinder. Therefore, engineers work in a ship engine-room for a long time have the trouble of hearing when they are exposed the high noise level. In this study, two kinds of vessels were used to investigate the noise of engine room, engine-control room, bridge, offices and cabins. As criteria of sound levels, A-weighted sound pressure level and octave band pressure level were used.

• 한국소음진동공학회논문집
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• 제22권3호
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• pp.264-274
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• 2012

Evaluation on the environmental noise is carried out by surveying subjective response of residents with physical measurement of noise during long period in field. Particularly field survey is used to make regulations from the analysis on how many people are annoyed for specific noise level, and laboratory test used to analyze the relationship between physical parameters of noise and subjective responses. In the laboratory controlling the variables is easy but the results could be biased because the condition in room would be different with field. Most of all noise exposure time is considered to be different with real situation, and this study aimed to evaluate the subjective response by exposure time of transportation noise, by applying three kinds of variable how much they give effects on the annoyance as the exposure time is operating condition, windows type and sound level. As a result there was somewhat difference between operating type and annoyance, which is caused by the sound characteristics operated in different condition. However the window type didn't give much effect to the annoyance as much as sound type. This means that the subjective response could give similar result by exposure time even for different window types. Most of all, the main factor affecting subjective response is considered to be the sound level and the exposure time.

• 환경위생공학
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• 제13권3호
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• pp.66-71
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• 1998

This study was investigated to evaluate worker exposures to organic solvents by type of print industry. Results were as follows; 1. Workers were exposed to mixture of toluene, isopropyl alcohol(IPA), methyl ethyl ketone(MEK), n-hexane, ethylacetate(EA), acetone. The components of high exposure solvents were toluene, IPA and MEK. 2. Considering additive effects of the compounds, exposure indices(Em) were calculated. The Mean of exposure indices were 1.79 for Gravere, 0.41 for Screen and 0.14 for Opset workplace. The workers of Gravere workplace were estimated to overexpose for solvents. 3. The highest overexposed solvent was toluene for a single component. The rate of overexposed level for toluene was 7.41% for some print workplace and for mixed solvent was 1.85％. 4. Local exhaust systems were inappropriate and respiratory protective devices were not supplied to the workers. 5. Sound level was over 90dB(A) in Opset print workplace and some measures should be performed to get down the sound level.

• 한국산업보건학회지
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• 제5권2호
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• pp.128-136
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• 1995

The purpose of this study is to evaluate the difference of noise level according to noise measuring methods in the noisy working environments. Sound pressure level(SPL), equivalence sound level(Leq) and personal noise exposure dose(Dose) in the fifty-nine unit workplaces of the twenty-eight industries were measured and relating factors which were affected noise level were investigated. The results were as follows ; 1. The noise levels were $88.70{\pm}5.68dB(A)$ by SPL, $89.07{\pm}5.41dB(A)$ by Leq and $89.07{\pm}5.69$ by Dose. The differences of noise levels by three measuring methods were statistically significant(P<0.001) by repeated measure ANOV A. 2. Comparing with noise levels by general classes of noise exposure, noise levels of continuous noise were $89.14{\pm}5.19dB(A)$ by SPL, $89.45{\pm}4.65dB(A)$ by Leq and $90.04{\pm}5.09$ by Dose. Noise levels of intermittent noise were $87.90{\pm}6.52dB(A)$ by SPL, $88.40{\pm}6.63dB(A)$ by Leq and $90.10{\pm}6.80$ by Dose. The differences noise level of noise measuring methods by general classese of noise exposure were statistically not significant by repeated measure ANOV A. 3. Interaction between general classese of noise exposure and noise measuring methods for noise level was not statistically significant by repeated measure ANOVA. And the noise level by noise measuring methods were statistically significant by repeated measure ANOV A(P<.001) 4. Comparing with noise levels by unit workplace size, noise levels of large unit workplace were $90.73{\pm}5.87dB(A)$ by SPL, $91.32{\pm}5.50dB(A)$ by Leq and $91.82{\pm}6.06$ by Dose and noise levels of middle unit workplace were $88.31{\pm}5.26dB(A)$ by SPL, $88.41{\pm}4.83dB(A)$ by Leq and $89.69{\pm}5.05$ by Dose. And noise levels of small unit workplace were $94.89{\pm}4.10dB(A)$ by SPL, $85.35{\pm}4.11dB(A)$ by Leq and $86.87{\pm}4.98$ by Dose. The noise level differences of noise measuring methods by unit workplace size were statistically significant by repeated measure ANOV A(P<.05). 5. The noise level by noise measuring methods were statistically significant by repeated measure ANOV A(P<.001). But Interaction between workplace size and noise level measuring methods for noise level was not statistically significant by repeated measure ANOVA. According to the above results, there was a difference of the noise level among the three measuring methods. Therefore we must use the personal noise exposure dose using by noise dose meter, possible, to prvent occupational hearing loss in noisy working environment.

• 한국소음진동공학회논문집
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• 제18권7호
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• pp.746-755
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• 2008

This research presents a laboratory study on subjective response of impulsive sound caused by construction site (breaker and blasting). The sources are sampled from outdoor noise and their levels range from 40 to 75 dBA at the interval of 5 dBA. The noise unit is based on A-weighted sound exposure level(ASEL; $L_{AE}$). To make equal ASEL of listening level, finite impulse response(FIR) filter is applied to the originally sampled source to include the effect of propagation attenuation. Sixty-three subjects, forty-two males and twenty-one female, between 18 and 29 years of age, participated in the experiment. The evaluation method of jury test adopted a semantic difference method(SDM). In the test results for impulsive noise, the subjective response of blasting noise was higher than that of breaker noise. The result of %HA that has been combined responses of the three methods except for pink-noise was executed by regression analysis and was shown as the following equation.: $%HA=746.53/(1+{\exp} (L_{AE}-93.3))+0.34$.

• 한국산업보건학회지
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• 제23권3호
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• pp.261-265
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• 2013

The purpose of this study was to evaluate noise level exposures at different locations such as the left and right ears of the shooter, control room, waiting soldier location and drill ground. For this study, we visited two military rifle ranges and took measurements with a sound level meter (3M Quest SoundPro TM) at five different locations with values of Peak (dB(A)) and Max (dB(A)). The highest peak value of impulse noise level averaged 150.4 dB(A), ranging from 149.6 to 150.5 dB(A) at both the left and right ear sides. This result was significantly different between both left and right ear side locations and at other locations such as the control room, waiting soldier location, and drill ground (P < 0.001). Frequency of impulse noise exposure level showed that the left ear of shooter had the highest frequency (20 times) at over 150 dB(A). This study confirmed that there is a need for proper controls to reduce the amount of impulse noise exposure at military rifle ranges.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.1191-1196
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• 2007

This research presents a laboratory study about an annoyance of impulsive sound caused by construction site(breaker and blasting). The sources are sampled from outdoor noise and their levels range from 40 to 75 dB at the interval of 5dB. The noise unit is based on A-weighted sound exposure level (ASEL; $L_{AE}$). To make equal ASEL of outdoor noise, finite impulse response (FIR) filter is applied to the originally sampled source to include the effect of distance attenuation. The evaluation method of jury test adopted a Semantic Difference Method (SDM). In the result of the Jury test for impulsive noise, the annoyance response of blasting noise was higher than that of breaker noise.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 춘계학술대회논문집
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• pp.714-720
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• 2008

This research presents a laboratory study about an subjective response of impulsive sound caused by leisure shooting. The sources are sampled from outdoor noise and their levels range from 40 to 75 dB at the interval of 5dB. The noise unit is based on A-weighted sound exposure level (ASEL; $L_{AE}$). To make equal ASEL of outdoor noise, finite impulse response (FIR) filter is applied to the originally sampled source to include the effect of distance attenuation. The evaluation method of the jury test adopted a Semantic Difference(SD) Method. In the result of the jury test for impulsive noise, the mean response rating expressed a linear relation and %HA(percent highly annoyed) displayed a exponential growth relation.

• Journal of Oral Medicine and Pain
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• 제35권1호
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• pp.49-59
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• 2010

본 연구는 단기간의 인공소음과 음악 청취에 대한 저작근의 반응을 조사하였다. 연구의 가설은 높은 소음은 작은 소음이나 음악에 비하여 저작근의 경도는 높이고 탄성도는 감소시킨다는 것이다. 15명의 지원자에게 60 dB 과 100 dB 의 소음과 음악을 각각 6분씩 들려주고 청취 전과, 청취 2분후, 4분후, 6분후에 tactile sensor system을 이용하여 교근과 측두근의 경도 및 탄성도를 조사하였다. 첫째날은 100 dB의 소음, 둘째날은 100 dB 의 음악, 셋째날은 60 dB 의 소음, 넷째날은 60 dB 의 음악을 청취한 후 조사하였다. 실험 결과, 60 dB, 100 dB 모두에서 소음과 음악 청취군 간에는 유의성 있는 차이가 대부분 없었으며, 60 dB, 100 dB군간의 비교에서 측두근에서는 유의한 차이가 없었으나 교근의 경우, 음악군에서는 탄성도에서, 소음군에서는 경도에서 유의한 차이를 보여주었다. 이는 소음의 종류에 관계없이 비록 음악이고 단기간의 청취일지라도 큰 소음인 경우에는 저작근의 수축을 야기할 수 있음을 의미한다.