• 한국물환경학회지
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• 제22권4호
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• pp.706-710
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• 2006

To evaluate impacts of the construction noise, Trionyx sinensis, inland fishers aquacultural organism, were exposed to control groups (about 55 dB) and noise groups (80 dB). The survival, growth rate and feeding efficiency of the juvenile Trionyx sinensis were measured at 10, 20 and 30 days intervals (each 9 hours/day). No significant mortality occurred during the experiments, but growth rates (1.7 times) and feeding efficiency (1.83 times) showed significant reduction in time-dependent manner. Also, serum cortisol (6.7 times) and corticosterone levels (1.37 times) in noise groups significantly increased by the noise exposure, compared to the controls, In conclusion, this study may provide the fundamental knowledge on adverse effects Trionyx sinensis and apply to assessments on the impacts of aquaculture industry by construction noise.

• 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.

• 한국방사선학회논문지
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• 제15권1호
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• pp.21-28
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• 2021

전산화단층촬영장치 (computed tomography, CT)는 다른 방사선 촬영 장치와 비교하면 피폭이 많다는 문제점이 있다. 이러한 피폭을 감소하기 위하여 저선량 촬영을 하게 되면 영상에 잡음이 증가하게 된다. 이를 보완하기 위해 환자의 피폭선량은 감소시키면서 영상의 화질을 향상하는 다양한 잡음 제거 알고리즘이 개발되었으며, 그 중 우수한 시간 분해능을 가진 CT 장치에 효과적으로 적용할 수 있는 median modified Wiener filter (MMWF) 알고리즘이 제시되었다. 본 연구의 목적은 MMWF 알고리즘의 마스크 크기를 최적화하고, 기존의 알고리즘들에 대한 MMWF 알고리즘의 잡음 제거의 우수성을 보는 것이다. MATLAB 프로그램을 이용하여 획득한 Gaussian 잡음이 부가된 MASH 팬텀 복부 영상들로부터 각각의 마스크 크기가 설정된 MMWF 알고리즘을 적용한 후 root mean square error (RMSE), peak signal-to-noise ratio (PSNR), coefficient correlation (CC) 그리고 universal image quality index (UQI) 값을 비교하였다. 그 결과 5 × 5 마스크 크기에서 RMSE 값이 가장 낮고, PSNR, CC, UQI 값이 가장 높았다는 것을 확인할 수 있었다. 또한, 최적화된 마스크 크기로 Gaussian 필터, median 필터, Wiener 필터에 대한 MMWF의 RMSE, PSNR, CC, UQI 값을 비교하였으며 그 결과 MMWF 알고리즘에서 가장 개선된 RMSE, PSNR, CC, UQI 값을 얻을 수 있었다.

• Journal of Preventive Medicine and Public Health
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• 제10권1호
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• pp.94-101
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• 1977

Noise pollution, both in the environment and in the workplace, has been recognized as a major health hazard -one that can impair not only a person's hearing but also his physical and mental well-being. As industrialization progresses, the prevalence rate of occupational diseases is increasing, especially hearing loss, which has the highest prevalence rate among the occupational diseases. The major cause of noise is the construction of various large industries without any regulation of noise sources. Therefor, we must establish an enactment to control mechanical noise sources. as soon as possible. For the purpose of controlling the noise source, we must have exact data about such things as the sound level, the frequency of the peak sound and the revolutions per minute (r.p.m.) of the machine (a measure of the power of its motor). This study was undertaken in order to define the noise characteristics, the power of the machine's motor, the change of the sound level and the peak sound as the r.p.m. increases, and the permissible exposure time. The sample size of this study was 74 machines at 11 plants in 6 industries. The results are as follows; 1. The breakdown of the types of mechanical noise noted was : 63.6% continuous normal sound, 26.9% intermittent sound, 4.7% continuous repeating sound and 4.6% impulsive sound. 2. With respect to the type of industry, the overall sound level was the highest in the mechanical industry, with $103.8{\pm}2.8dB(A)$, and lowest in the textile industry, with $89.2{\pm}1.43dB(A)$. 3. With respect to the type of machine, the highest sound level was 124 dB(A) caused by Gauzing(II), in the mechanical industry, and the lowest was 76 dB(A) caused by Attachment (Jup Chack) (I) in the timber industry. 4. The shortest permissible exposure time to Gauzing(II) in the mechanical industry was less than 15 minutes. 5. Among 74 machines, 68.2% of the peak sound was situated in the high frequency range (52.7% at 2 KHz, 4.1% at 4 KHz and 1.4% at 8 KHz). 41.8% of the peak sound was in the middle frequency range (4.1% at 250Hz, 14.8% at 500Hz and 22.9% at 1KHz). 6. If one machine had two motors or more, the peak sound was shifted to the low frequency range. 7. As the r.p.m. increased, the overall and peak sound levels were increased without any change of the frequency of the peak sound. 8. Whenever the machines had the same kind and the same r.p.m., the overall and peak sounds were changed by the physicochemical characteristics of the raw materials and the management.

• 한국산업보건학회지
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• 제6권2호
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• pp.281-291
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• 1996

458 female workers working in the small and medium scaled industries in Inchon area were surveyed to study their general characteristics, health behavior, working and environmental conditions, awareness of exposure at hazardous materials, current health status, and degree of working satisfaction. Self-administered questionnaire was distributed to the female workers with the explanation by trained interviewer on the purpose of survey and the method how to answer. The results were as follows : (1) 75.5% of the respondents are living with their families and others are living in domitary or rent house for herself. Age distribution ranges from teenagers to warren in their forties. In marital status 69.0% of workers are single and 31.0% of them have ever married. 69.4% of workers are high school graduate. The size of factory is 48.3% with less than 300 workers, 42.1% with 300~500 workers. (2) Most of the workers(86.7%) are full time workers, 52% of the respondents have working experiences in other factories. More than 65% have fewer than 5 years working experience. (3) The awareness of exposure at noise was 33% of respondents, it was significantly different by skilled status. The awareness of exposure at dust, other hazardous material was each 13.3%, 12.4% of respondents. (4) 26% of them are unsatisfied with their working cognitions and 43.7% of them are unsatisfied with their welfare in occupational system unsatisfactory rate of promotion is higher in the unmarried workers(45.6%), skilled workers(47.2%), full time workers(47.4%), long term workers(50%), and awareness group of exposure hazardous material(51.3%), compared to married women workers, unskilled workers, part-time workers, short term workers and unawareness group of exposure at hazardous materials. (5) The index of working satisfaction is rated on a scale of 1 to 10 with the higher point indicating higher satisfaction. Among the selected variables, marital status, working status, the awareness of exposure at hazardous materials, were statistically significant with the index of working satisfaction. (6) By multiple regression analysis showed that the determinant factors of index of working condition were health index, the awareness of exposure at dust, the awareness of exposure other hazardous materials, marital status and working period. In conclusion, there is a significant relationship between the awareness of exposure at hazardous material the index of working satisfaction. Therefore if the workers are less exposed to the hazardous material and are educated properly they will be more satisfied with their work thus improving their health and productivity. Finally, with the result of this study, there is a great need for the development of a health promotion program and a welfare policy for small-scale factories.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.262-266
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• 2014

Military vehicle equipped with an antenna and a shelter for operating radar has a vibration exposure during driving time. This vibration would have influence on structure of military vehicle critically. In this paper, driving stability of the military vehicle is obtained through the vibration response analysis. And, vibration level of the military vehicle satisfied the military vibration specification through analysis and comparing the MIL-STD-810G. PSD and Grms data obtained by road test can be used for vibration test specification of cabinets and electronic equipment in shelter.

• 대한기관식도과학회:학술대회논문집
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• 대한기관식도과학회 1972년도 춘계종합 학술대회 초록집
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• pp.7-8
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• 1972

세계이차대전을 계기로 전쟁으로 인한 난청의 피해는 물론이고 각방면의 산업이 급히 발달함으로서 소음에 대한 문제는 사회적 또는 법의학적인 면에서 여러가지 문제점을 제시하게 되었다. 소음이 인체에 미치는 영향은 크게 일반적인 피해와 청각적인 피해로 분류해서 생 각 할 수 있다. 일반적인 피해 많은 실험으로 수면장해, 불쾌감, 정서 등에 나쁜 영향을 주며 작업능률이 떨어진다는 점을 증명하였다. 생리기능에도 작용해서 Laird등은 50∼60 phone의 소음으로 타액, 위액의 분비가 감소되고 혈압상승, 맥박수의 증가, 말초혈관의 수축 등을 일으킨다고 보고하였다. 또한 내분비계에 작용해서 부신홀몬의 감소 gonado-tropine분비가 감소되고 갑상선자극 홀몬은 증가한다고 한다. 청각적인 피해 19세기경부터 소음때문에 청각장해를 일으킨다는 보고가 있고 그후 많은 학자들에 의하여 소음과 난청에 대한 연구보고가 있다. 1947년 Weiss는 이차대전때 청력을 잃은 수가 15만명 정도로 보고하였는 바 다른 사람은 30만명으로 보고하였다. 근래에 교통수단의 발달과 기계공업의 발전으로 여러 가지 복잡한 보상문제 또는 법적인 문제들이 야기됨으로 충분한 지식과 과학적인 판단이 더욱 필요하게 되였다. Sataloff는 jet engine no에서 종사하는 사람들에게서 난청은 한사람도 없었다는 보고도 있으나 Sterner는 85㏈∼100㏈의 소음으로 난청이 온다는 보고가 있으며 여하튼 80㏈ 이상의 소음장에서 일하는 사람은 주기적으로 청력검사를 시행하여 일시적인 청력피로가 있을 때 휴식을 취하게 함으로서 영구적인 불행을 방지하며 소음원에 대해서는 차음을 하고 근로자에게는 외이도에 적당한 plug 을 하든가 muff을 사용하여 피고용자와 고용인 양쪽에 다같이 이익을 도모하도록 노력을 하는 것이 우리의 의무일 것이다.하였다.2002년 4월에 최대치에 도달했다. 전체 숙주와 바이러스 밀도로 볼 때, 그들의 먹이사슬은 바이러스에 의한 사멸에 의해서 평형 상태로 유지되고, 바이러스의 밀도 또한 평형 상태를 유지하는 것으로 보였다. 이러한 시도는 우리나라 광양만 내에 존재하는 해양 바이러스의 생태적 분포 연구를 다루는 첫 번째 실험으로 사료된다.탄산염암 지역은 Ca-$HCO_3$형, 혼펠스 지역은 Na-K형과 $CO_3+HCO_3$형이 우세한 것으로 나타났다. 본 연구를 통해 달천 폐광산 지역의 광미적재지에서 $Ca^{2+},\;Mg^{2+}$ 및 $SO_4^{2-}$ 성분이 지하수에 다량 용해되어 지하수의 주 흐름 방향에 위치한 기반암 지하수에 유입되었음을 알 수 있었다.tic monks could not wear. to express their deep faith. So the rules of the samgha has been distorted. The samgha has enlarged day by day as a great huge religious association. There are many different shapes of Kasaya. The Buddhist samgha need to establish a minute and rigid rules of Kasaya to order living of monks and to teach the moral and educational life to ordinary people. That book of rule is Vinaya pitaka(율장) . There are many kinds of Vinaya pitaka. This paper surveys the rules of Kasa

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2007년도 하계종합학술대회 논문집
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• pp.235-236
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• 2007

CCD(Charge-Coupled Device) 혹은 CMOS (Complementary Metal Oxide Semiconductor)와 같은 소자를 이용하여 빛을 전기적 신호인 Image로 재구성하는 촬상소자(Color Capture Device)는 촬영환경이 어두워지면 Dynamic Range가 작아지고, Noise가 상대적으로 심해진다[1][2]. 본 논문에서는 촬영 환경이 어두울 때, Resolution을 Preserving하는 Pixel Pitch가 큰 촬상 소자와 Motion Blur를 억제하는 Exposure Time이 긴 촬상 소자의 조합을 신호처리로 구현하여, 신호의 Power를 향상시켜 Dynamic Range를 키우고 Noise의 Boost-up을 억제하여 SNR(Signal to Noise Ratio)을 향상시키는 방식으로, 촬상 장치의 감도를 향상시켜 화질을 개선하는 방법을 제안한다.

• 한국컴퓨터정보학회논문지
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• 제28권8호
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• pp.165-174
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• 2023

본 연구는 국내 근로환경조사 자료를 이용하여 조사 시기에 따른 제조업 종사자의 유해·위험요인 노출과 결근과의 관련성을 확인하였다. 이에 2011년도(3차), 2017년도(5차), 2020년도(6차)의 유해·위험요인 동일문항에 대하여 제조업 종사자 8,318명을 대상으로 분석하였다. 업무 관련 유해·위험인자와 결근과의 관련성을 보면 2011년도에 비하여 2020년도에 진동, 소음, 높은 온도, 먼지 등의 흡입, 증기흡입, 화학물질 취급, 감염물질 취급에서 노출 시간 3/4 이상이 결근에 영향을 미치는 것으로 나타났다. 결론적으로 업무 관련 유해·위험요인에 대해서는 조사시기가 증가함에 따라 비노출이 증가함을 알 수 있었고 업무 관련 유해·위험요인의 노출 시간이 결근에 영향을 미친다는 것을 확인할 수 있었다.

• Safety and Health at Work
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• 제14권3호
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• pp.279-286
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• 2023

Background: This study aimed to evaluate the association between exposure to occupational hazards and the metabolic syndrome. A secondary objective was to analyze the additive and multiplicative effects of exposure to risk factors. Methods: This retrospective cohort was based on 31,615 health examinees at the Pusan National University Yangsan Hospital in Republic of Korea from 2012-2021. Demographic and behavior-related risk factors were treated as confounding factors, whereas three physical factors, 19 organic solvents and aerosols, and 13 metals and dust were considered occupational risk factors. Time-dependent Cox regression analysis was used to calculate hazard ratios. Results: The risk of metabolic syndrome was significantly higher in night shift workers (hazard ratio = 1.45: 95% confidence interval = 1.36-1.54) and workers who were exposed to noise (1.15:1.07-1.24). Exposure to some other risk factors was also significantly associated with a higher risk of metabolic syndrome. They were dimethylformamide, acetonitrile, trichloroethylene, xylene, styrene, toluene, dichloromethane, copper, antimony, lead, copper, iron, welding fume, and manganese. Among the 28 significant pairs, 19 exhibited both positive additive and multiplicative effects. Conclusions: Exposure to single or combined occupational risk factors may increase the risk of developing metabolic syndrome. Working conditions should be monitored and improved to reduce exposure to occupational hazards and prevent the development of the metabolic syndrome.