• 전자공학회논문지T
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• 제36T권2호
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• pp.70-76
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• 1999

최근에 휴대전화기가 저 연령층까지 널리 보급되어 어린이들의 두부내에 열점(hot-spot)형성문제가 염려되고 있는 실정이다. 전자파의 인체영향이 체온상승의 열적작용에 의한 것이라고 생각한다면 휴대전화기에 의해 발생하는 두부내 국소SAR의 인체영향도 두부의 온도상승과 연관된다고 추정된다. 본 논문은 휴대전화기를 실사용 상황에서 시간대별 두부의 국소부위에 대한 온도변화를 측정하였다. 그 결과 휴대전화기의 통화시작점에서 계속적인 온도상승을 보이다가 통화가 끝나는 시점에서 두부의 국소적인 온도변화는 빠르게 회복되지만 생체전신의 평균온도는 상승함을 알 수 있었다.

• 한국환경복원기술학회지
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• 제24권6호
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• pp.97-107
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• 2021

Abnormal climate caused by climate change causes enormous social and economic damage. And such damage and its impact may vary depending on the location and regional characteristics of the region and the social and economic conditions of local residents. Therefore, it is necessary to continuously monitor whether there are indicators that are weaker than other regions among the detailed indicators that constitute the risk, exposure and vulnerability of climate change risk. In this study, the concept of climate change risk was used for heatwave to determine regional inequality of climate change risk. In other words, it was judged that inequality in climate change risk occurred in regions with high risk but high exposure and low vulnerability compared to other regions. As a result of the analysis, it was found that 13 local governments in Korea experienced regional inequality in climate change risk. In order to resolve regional inequality in climate change risks, the current status of regional inequality in climate change should be checked based on the analysis proposed in this study, there is a need for an evaluation and monitoring system that can provide appropriate feedback on areas where inequality has occurred. This continuous evaluation and monitoring-based feedback system is expected to be of great help in resolving regional inequality in climate change risks.

• 한국멀티미디어학회논문지
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• 제25권9호
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• pp.1273-1283
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• 2022

This paper presents a locally adaptive HDR algorithm using the integral image and MSRCR for LDR images with inadequate exposure. There are two categories in controlling the dynamic range, which are global and local tone mappings. Since the global ones are relatively simple but have some limitations at considering regional characteristics, the local ones are often utilized and MSRCR is a representative method. MSRCR gives moderate results, but it requires lots of computations for multi-scale surround Gaussian functions and produces the Halo effect around the edges. Therefore, in order to resolve these main problems, the proposed algorithm remarkably reduces the computation of the surrounds due to the use of the integral image. And a set of variable-sized windows is adopted to decrease the Halo effect, according to the type of pixel's region. In addition, an offset controlling function is presented, which is mainly affected to the subjective image quality and based on the global input and the desired output means. As the results, the proposed algorithm no more use Gaussian functions and can reduce the computation amount and the Halo effect.

• 한국산업보건학회지
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• 제25권2호
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• pp.134-145
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• 2015

Objectives: An objective of this study was to perform a risk assessment and social cost-benefit analysis for revising permissible exposure limits for seven substances: Nickel(Insoluble inorganic compounds), benzene, carbon disulfide, formaldehyde, cadmium(as compounds), trichloroethylene, touluene-2,4-diisocyanate. Materials and Methods: The research methods were divided into risk and hazard assessment and cost-benefit analysis. The risk and hazard assessment for the seven substances consists of four steps: An overview of GHS MSDS(1st), review of document of ACGIH's TLVs (2nd), comparison between international occupational exposure limits and domestic permissible exposure limits(3rd), and analysis of excess workplace and excess rate for occupational exposure limits based on previous work environment measurement data(4th). Total cost was estimated using cost of local exhaust ventilation, number of excess workplace and penalties for exceeding a permissible exposure limit. On the other hand, total benefit was calculated using the reduction rate of occupational disease, number of workplaces treating each substance and industrial accident compensation. Finally, the net benefit was calculated by subtracting total cost from total benefit. Results: All the substances investigated in this study were classified by CMR(Carcinogens, Mutagens or Reproductive toxicants) and their international occupational exposure limits were stricter than the domestic permissible exposure limits. As a result of excess rate analysis, trichloroethylene was the highest at 11%, whereas nickel was the lowest at 0.5%. The excess rates of all substances except for trichloroethylene were observed at less than 10%. Among the seven substances, the total cost was highest for trichloroethylene and lowest for carbon disulfide. The benefits for the seven substances were higher than costs estimated based on strengthening current permissible exposure limits. Thus, revising the permissible exposure limits of the seven substances was determined to be acceptable from a social perspective. Conclusions: The final revised permissible exposure limits suggested for the seven substances are as follows: $0.2mg/m^3$ for nickel, 0.5 ppm(TWA) and 2.5 ppm(STEL) for benzene, 1 ppm(TWA) for carbon disulfide, $0.01mg/m^3$(TWA) for cadmium, 10 ppm(TWA) and 25 ppm(STEL) for trichloroethylene, 0.3 ppm(TWA) for formaldehyde, and 0.005 ppm(TWA) and 0.02 ppm(STEL) for toluene diisocynate(isomers).

• 한국전자파학회논문지
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• 제15권3호
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• pp.291-300
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• 2004

이동통신 서비스의 급격한 증가로 인해, EMF(Electromagnetic field)노출의 생물학적 효과에 대한 많은 연구들이 수행되어져 왔다. 그러나 연구 수행에 있어서 필요한 무선 주파수 대역에서의 균일장 생성은 쉬운 일이 아니다. 이러한 어려움을 극복하기 위해 전신노출 시 스템에서의 전기장과 SAR(Specific Absorption Rate) 분포 측정이 발전을 해왔다. 본 논문에서는 EMC 대용 챔버로의 활용 가능성이 높은 전자파 잔향실 챔버를 이용하여 동물 실험용 전신 노출 장치를 개발하였다. 설계된 전자파 잔향실은 시뮬레이션과 측정 데이터를 이용하여 시험영역의 균일장에 대한 유효성을 검증하였다. 마우스에 대한 전신노출 실험에 있어서, 노출된 전자파에 대해 SAR을 확인하기 위해서 FDTD수치해석 방법과 측정 결과를 비교하였다. 전자파 잔향실 내부에서의 전기장 분포 특성을 해석하고, 이러한 해석 결과들을 통계적으로 처리하였다. CDMA 이동전화 주파수 대역에서(PCS ＆ Cellular 대역) 입력 파워 변화에 따른 실험상태에서의 마우스 전신 SAR 평균값 및 국부 최대값을 제시하였다.

• 한국지역사회생활과학회지
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• 제18권4호
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• pp.599-607
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• 2007

We analyzed the effects of regular Jjimjilbang (Korean sauna) exposure on the cold tolerance in young and elderly females. Subjects were young (n=7) and elderly (n=7) females who had never had Jjimjilbang exposure experience. The Jjimjil training group was exposured in the Jjimjilbang 19 times per week. Jjimjibang exposure was limited to three times per day. Jjimjil activity was taken freely. To prove the effects of the cold tolerance, subjects were exposed to cold air ($12{\pm}1^{\circ}C,\;60{\pm}10%$RH). In these conditions, subjects were exposed for 30 minutes at which time rectal temperature, skin temperatures, clothing microclimate, energy expenditure, blood pressure and subjective sensation were measured. To prove the effects of the local cold tolerance, vascular hunting reaction was observed measuring the finger skin temperature while the left middle finger tip was immersed in cold water of $0^{\circ}C$ for 30 minutes. The results are as follows. According to repeated Jjimjil exposure, rectal temperature changes, peripheral temperature and energy expenditure were increased gradually in the cold climate chamber. Blood pressure, subjective sensation and vascular hunting reactions did not show any significant difference. In conclusion, regular Jjimjilbang exposure has negative effects on the ability of the body to improve its regulation of temperature especially in cold tolerance.

• 대한교통학회지
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• 제31권5호
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• pp.26-36
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• 2013

지역단위 도로교통안전도에 대한 거시적 평가는 인구, 자동차대수, 도로연장 등의 거시적 노출변수(Macroscopic Exposure Measures)에 기반한 사고율을 노출지표로 이용하는 것이 일반적이나, 노출지표를 이용한 도로교통안전도 평가에 노출지표들이 미치는 영향이 각기 다르기 때문에 결과적으로 각각의 개별노출지표별 평가시 평가결과가 서로 상이하게 되는 문제가 있으며, 이는 예산투자의 효율적 집행을 위한 교통안전정책의 결정과정에 방해요인으로 작용하게 된다. 따라서 본 연구에서는 최소제곱법 및 가중치를 일정단위로 변화시키는 시뮬레이션을 이용하여 노출지표별 최적의 가중치를 도출하였으며, 이를 종합적으로 반영할 수 있는 도로교통안전도 비교평가지수 산정방법을 개발하였다. 지수를 구성하는 노출지표별 가중치는 인구당사고율이 0.29, 자동차등록대수당사고율이 0.52, 도로연장당 사고율이 0.19로 도출되었으며, 개발된 방법을 적용하여 전국 기초지자체별로 도로교통안전도 비교평가지수를 산정하였다. 본 연구에서 제시한 방법을 통해 노출지표별로 평가결과가 상이해지는 문제를 해결할 수 있으며, 교통안전예산의 투자효율성을 높이기 위한 교통안전정책의 합리적인 결정방법으로 활용될 수 있을 것으로 판단된다.

• 한국산업보건학회지
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• 제29권3호
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• pp.271-277
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• 2019

Objectives: A 46-year-old woman who had worked on cleaning stainless steel containers with Initially unknown powders died from acute silicosis. To determine whether the acute silicosis was related to his work environment, we conducted exposure assessment the level of exposure to respirable crystalline silica(RCS) during cleaning stainless steel containers with unknown powders. Methods: The exposure assessment of RCS were undertaken according to the National Institute for Occupational Safety and Health(NIOSH) method 7500. The components of the unknown powder were analyzed using X-ray Diffraction. Results: The unknown powder was found to be natural diatomaceous earth, which contained 12% and 9% quartz and cristobalite, respectively, crystalline silica. In the case of cleaning stainless steel containers with diatomaceous earth powder, the primary measurement resulted in 1.3 times higher occupational exposure limit of MOEL(in sum of quartz and cristobalite concentration) and 3.9 times higher in secondary measurement. The workbench was equipped with a local exhaust system, but because there was no hood at the end of the duct, the wind speed at the opening of the duct was 12 m/sec, whereas the controlled wind speed at the working position was only 0.3 m/sec below the legal standard. Conclusions: There is an urgent need to install the hood, conduct safety and health education for employers and workers, and periodically monitoring and manage the working environment.

• 한국산업보건학회지
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• 제10권1호
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• pp.45-57
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• 2000

Results of environmental monitoring for 35 steel industry welders exposed to manganese and chromium fume were evaluated. Efficiency of respiratory protectors, welding face shields and local exhaust ventilation were also evaluated to establish more efficient preventive measures that can protect welders from occupational disease as related to welding fume. The results are as follows; 1. Total fume from $CO_2$ arc welding with mild steel occurred 1.5 to 2.2 times more than that from shielded metal arc welding. Chromium and nickel fume from welding with stainless steel occurred 27 to 59 times and 18 to 30 times, respectively, than those with mild steel. 2. Proportions of water-soluble chromium(VI) and insoluble chromium(VI) Compare to total chromium occurring from $CO_2$ arc welding with stainless steel were 10.5% and 8.7%, respectively, while those with mild steel were 57.1 to 63.2% and 31.6 to 38.1%, respectively. 3. The efficiencies of 4 types of respiratory protectors to reduce welding fume exposure were evaluated as 54.4 to 64.4%. 4. The reducing effect of head type welding face shield was 67.6%, and that of hand type welding face shield was 58.5%. The highest reducing effect was shown in air supply welding face shield as 99.2%, although it is not convenient to wear. 5. When welding face shield and respiratory protectors were worn together, the reducing efficiency increased to 79.0 to 87.5%. 6. When local exhaust ventilation was installed in workplace, the reducing efficiencies varied from 31.5 to 73.1% according to the types of welding.

• 한국의류학회지
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• 제31권9_10
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• pp.1465-1474
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• 2007

We analyzed the effects of regular Jjimjilbang(Korean sauna) exposure on the heat tolerance in young and old females. Subjects were young(n=7) and old(n=7) females who never had a bath in Jjimjilbang for last year. Jjimjilbang training group took a bath in Jjimjilbang once a week 19 times. Jjimjibang expsure was limited three times per day, Jjimjil were taken free way. To prove the effects of the heat tolerance, Subjects were exposed to hot and humid air$(40.0{\pm}0.5^{\circ}C,\;60{\pm}5%RH)$. In the condition, subjects were taken a foot bathing$(40.0{\pm}0.5^{\circ}C)$ and simulated for 30 min., and rectal temperature, skin temperatures, clothing microclimate, blood pressure, total body weight loss, local sweat and subjective sensation were measured. The results are as follow: Rectal temperature, skin temperatures, clothing microclimate, total body weight and subjective thermal comfort sensation were decreased gradually(p<.001). Local sweat of upper arm was decreased(p<.01). In conclusion. the regular Jjimjilbang exposure has positive effects upon improvement in regulation of body temperature, especially in heat tolerance.