• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.125-131
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• 2000

This study was performed to evaluate the whole-body vibration and occupational noise for excavator drivers. Measurement, evaluation and assessment were based on the ISO 2631 and OSHA. Average vibration level was 0.65m/$s^2$(z axis) for breaking work and 0.36 m/$s^2$(z axis) for excavating work. Vibration levels during breaking work exceed the health guidance caution zone and this means that the drivers are exposed to potential health risks. Average daily noise exposure level was 86.4 dB(A) for breaking work and 84.6 dB(A) for excavating work.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2010년도 춘계학술대회 논문집
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• pp.44-44
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• 2010

In this presentation, noise control materials will be discussed from several points-of-view. First, materials will be categorized in terms of their intended function: i.e., as dissipative materials, as barriers, and as media intended to modify some aspect of the sound field. Within each category, example implementations will be described as will modeling procedures. In the context of barrier materials, recent developments in the area of metamaterials will be described briefly, and problems with some recently suggested approaches will be highlighted. Acoustical cloaking will be described as a method of modifying a sound field in such a way that a sensitive area is shielded from noise exposure; the practical difficulties of this approach will also be described. Finally, within each category of material and approach, a series of suggested research challenges will be described.

• Journal of Acupuncture Research
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• 제19권2호
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• pp.105-113
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• 2002

Objective : The purpose of this study is to investigate the protective effect of DADS on the noise induced hearing loss Methods : Twenty healthy guinea pigs (DADS pretreated group and control) were exposed to 100dB a collected environmental noise for 9 hours. An auditory evoked brainstem response (ABR) threshold was measured before and after a noise exposure. For morphological study, cochlea was studied by scanning electron microscope (SEM). Results : The DADS pretreated group showed statistically significant less changes in ABR threshold and SEM findings compared the control group. Conclusion : From these results suggest that the DADS from garlic may have a protective effect in noise induced hearing loss.

• 한국환경보건학회지
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• 제45권6호
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• pp.668-674
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• 2019

Objectives: Modern people spend most of their day indoors. As the health impact of radon becomes an issue, public interest also has been growing. The primary route of potential human exposure to radon is inhalation. Long-term exposure to high levels of radon increases the risk of developing lung cancer. Radon exposure is known to be the second-leading cause of lung cancer, following tobacco smoke. This study measures the indoor radon concentrations in detached houses in area A of Chungcheongbuk-do Province considering the construction year, cracks in the houses, the location of installed detectors, and seasonal effects. Methods: The survey was conducted from September 2017 to April 2018 on 1,872 private households located in selected areas in northern Chungcheongbuk-do Province to figure out the year of building construction and the location of detector installed and identify the factors which affect radon concentrations in the air within the building. Radon was measured using a manual alpha track detector (Raduet, Hungary) with a sampling period of longer than 90 days. Results: Indoor radon concentrations in winter within area A was surveyed to be 168.3±193.3 Bq/㎥. There was more than a 2.3 times difference between buildings built before 1979 and those built after 2010. The concentration reached 195.4±221.9 Bq/㎥ for buildings with fractures and 167.2±192.4 Bq/㎥ for buildings without fractures. It was found that detectors installed in household areas with windows exhibited a lower concentration than those installed in concealed spaces. Conclusion: High concentrations of indoor radon were shown when there was a crack in the house. Also, ventilation seems to significantly affect radon concentrations because when the location of the detector in the installed site was near windows compared to an enclosed area, radon concentration variation increased. Therefore, it is considered that radon concentration is lower in summer because natural ventilation occurs more often than in winter.

• 대한소아치과학회지
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• 제39권3호
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• pp.267-272
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• 2012

치과의사는 감염, 알레르기, 시력장애 등 다양한 직업적 위험에 노출되어 있으며, 그 중에서도 비교적 최근 들어 새롭게 제기된 문제가 청력손상이다. 치과 진료실에서 발생하는 소음이 작업장 소음 기준을 초과한다는 조사 결과가 발표된 바 있고, 특히 소아치과 의사는 각종 치과 소음에 더하여 어린이의 울음소리라는 부가적 소음원에도 일상적으로 노출되고 있다. 본 연구는 소아치과 의사에게 영향을 미칠 수 있는 소음 환경에 대해 조사하고, 이에 따른 청력 손상 가능성을 고찰해 볼 목적으로 시행되었다. 휴대용 소음계를 이용하여, 각종 치과용 기구, 어린이의 울음소리, 양자가 동시에 발생할 때의 소음 크기를 각각 측정하고, 소아치과 의사가 소음 환경에 노출되는 시간을 설문을 통해 조사하였다. 이 결과를 National Institute for Safety and Health(NIOSH) 및 Occupational Safety and Health Act (OSHA)의 소음 역치 기준, CRA News letter의 청력 손상을 유발하는 소음 기준과 각각 비교하였다. 그 결과, 소아치과 의사가 노출된 소음 환경은, 강도와 노출 시간을 고려했을 때 허용된 작업장 소음 기준을 초과하며, 어린이의 울음소리는 한 번의 노출로도 영구적 청력 손상을 야기할 수 있는 수준으로 나타났다. 따라서 일반 치과의사와 비교하여 소아치과 의사는 직업적 청력 손상의 위험성이 더 높으며, 이를 최소화하기 위한 적극적인 대책이 필요하다는 결론을 내릴 수 있었다.

• 한국방사선학회논문지
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• 제15권5호
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• pp.731-739
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• 2021

이 연구는 산업현장에서 구조물의 용접부 검사를 디지털 방사선을 이용한 비파괴검사를 효과적으로 수행할 수 있도록 디지털 방사선의 밝기 교정과 중첩 영상에 따른 신호 대 잡음 비와 기본 공간 분해능을 비교분석 하였다. 평판형 용접 시험편을 대상으로 ⁷⁵Se 방사선원을 사용하였고 촬영 전 밝기 교정과 영상 중첩을 세분화하여 총 130장의 영상을 획득하였다. 연구 결과, 밝기 교정의 수와 영상 중첩의 수가 증가할수록 신호 대 잡음 비가 향상됨을 확인하였다. 기본 공간 분해능은 촬영된 영상 모두 기준치를 만족하였다. 산란 방사선을 대비한 납 차폐를 설치 후 촬영한 영상을 비교하여 신호 대 잡음 비가 비슷함을 확인하였다. 영상 중첩이 증가할수록 신호 대 잡음 비가 증가하지만, 방사선의 노출시간이 증가하면서 작업자의 피폭 및 작업 효율에 영향을 미치기 때문에 적절한 촬영기법을 강구 한다면 좋은 상질의 디지털 방사선 영상을 획득 할 수 있을 것으로 사료된다.

• Safety and Health at Work
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• 제15권2호
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• pp.220-227
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• 2024

Background: Though the artificial neural network (ANN) technique has been used to predict noise-induced hearing loss (NIHL), the established prediction models have primarily relied on cross-sectional datasets, and hence, they may not comprehensively capture the chronic nature of NIHL as a disease linked to long-term noise exposure among workers. Methods: A comprehensive dataset was utilized, encompassing eight-year longitudinal personal hearing threshold levels (HTLs) as well as information on seven personal variables and two environmental variables to establish NIHL predicting models through the ANN technique. Three subdatasets were extracted from the afirementioned comprehensive dataset to assess the advantages of the present study in NIHL predictions. Results: The dataset was gathered from 170 workers employed in a steel-making industry, with a median cumulative noise exposure and HTL of 88.40 dBA-year and 19.58 dB, respectively. Utilizing the longitudinal dataset demonstrated superior prediction capabilities compared to cross-sectional datasets. Incorporating the more comprehensive dataset led to improved NIHL predictions, particularly when considering variables such as noise pattern and use of personal protective equipment. Despite fluctuations observed in the measured HTLs, the ANN predicting models consistently revealed a discernible trend. Conclusions: A consistent correlation was observed between the measured HTLs and the results obtained from the predicting models. However, it is essential to exercise caution when utilizing the model-predicted NIHLs for individual workers due to inherent personal fluctuations in HTLs. Nonetheless, these ANN models can serve as a valuable reference for the industry in effectively managing its hearing conservation program.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.89-101
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• 2006

This study is a part of ???A study of the community noise:new guideline and policy' which have three main topics and ten sub-topics. Accordingly this part deals with a transpotation noise specifying road traffic ,railroad and aircraft noise, respectively. At first, the ,roadside traffic noise of whole country in 2004 ,22 major cities of total 29 was exceeded the envionmetal noise standards, 55dB(A) at night time ,therefore 24 milion people ,52.4% of korean, who reside at roadside estimates to be exposured the basic problems of this serious noise polluation comes from:: i)It's very limited noise mitigation measures against to continuously increase the number of automobile yearly. ii) and at beginning of road design, It has been neglect to introduce the anti-noise design and layout of road structural scheme as gadient,cutting and viaduct,embankment and zonning of roadside land-buffer area and also re-designation of noise sensitive areas,etc. Secondly ,concerned with the railroad trafffic noise, a inhabitants who are over the envionmetal noise limits,70dB(A), 65 dB(A) in day and night for 34 locations of mayor cities was exposured of 167,000 and 329,000 respectively. With the development of noise mitigation schemes in line with this study it is likely that noise monitoring system needs new installation as well as common use of noise assessment index with $L_{MAX}\;and\;L_{EQ}$. Lastly,noise complaints of millitary aircraft has been rapidly increasing ,so 2.9%(1.4 minion) person demands a compansation of \2,133 billion complying with their requirements we suggest to minimise the airport noise that is to develop of noise abatement procedure ,to make new noise index, to increase budget for house insulations and also to more increase of those the noise monitoring system and to unify the management etc.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.948-951
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• 2014

Road traffic noise is closely related with urban forms and urban components, such as population, building, traffic and land-use, etc. Hence, it is possible to minimize the noise exposure problem depending on how to plan new town or urban planning alteration. This paper provides ways to apply for urban planning in consideration of noise through exposed noise estimation for urban planning alteration. Spatial autoregressive model which explains about 81.4% of road traffic noise from the former paper is used. The simulation results by the spatial statistical model are compared with those by the engineering program-based modeling for 5 small-scaled scenarios of urban planning alteration. The error from the limitation of containing informations inside the grid cell and the difficulties of reflecting acoustic phenomena is existed. Nevertheless, in the stage of preliminary design, the use of the statistical models that have been estimated well is useful in time and economically.

• 한국감성과학회:학술대회논문집
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• 한국감성과학회 1999년도 춘계학술발표논문집 논문집
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• pp.127-132
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• 1999

Cardiovascular, respiratory and electrodermal responses to acute stress episodes modeled by combined presentation of intense white noise and performance of word recognition task with noise background were studied in 15 college students. Experimental procedure consisted in sessions with white noise, word recognition task presentation with noise background and test with noise background. Recorded physiological variables were analyzed in terms of their sensitivity to detect activation of sympathetic and parasympathetic branches of autonomic nervous system and thus reflect autonomic arousal level during shout-term stress-inducing experimental manipulations. It was shown that performance of effortful mental task with noise background elicited significant physiological responses typical for active coping behavior, namely electrodermal arousal and increased cardiovascular activity. this response profile was more profound as compared to white noise only or attending task in noise background. However, all physiological responses were mostly phasic, without long-term tonic changes, since almost all variables recovered to their initial baseline levels, suggesting that dominant autonomic mechanisms in transient acute stress episodes were of parasympathetic nature (withdrawal in stress with subsequent activation in restoration period), while sympathetic contribution was not long-lasting. Nevertheless, increased number of stressors and their longer exposure may result in higher profile of tonic sympathetic arousal and reduced functional role of vagal mechanisms in autonomic balance regulation.