• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.753-756
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• 1991

This paper aimed to analyse dose sensitivity to the controllable parameters of in-door radon $(^{222}Rn)$ and its decay products(Rn-D) by applying the input-output linear system theory. Physical behaviors of $^{222}Rn$ & Rn-D were analyzed in terms of $^{222}Rn$ gas generation, -migation and - infiltration to indoor environments, and the performance output-function(i.e. mean dose equivalent to Tracho-Bronchial(TB) lung region was assessed to the following ranges of the controllable parameters; a) the ventilation rate constant $({\lambda}_v)$ : $0{\sun}500[h^{-1}]$. b) the attachment rate constant$({\lambda}_a)$ : 0-500 $[h^{-1}]$. c) deposition rate constant $({\lambda}{_{d}^{u}})$: 0-50$[h^{-1}]$. A linear input-output model was reconstructed from the original models in literatures, as follows, which was modified into the matrices consisting of 111 nodal equations. a) indoor ${222}Rn$ & Rn-D Behaviour: jacobi- Porstendorfer- Bruno model. b) lung dosimerty : Jacobi-Eisfeld model. Some of the major findings, which identify the effectiveness of this model, were as follows. a) ${\lambda}_v$ is most effective, dominant controllable parameters in dose reduction, if mechanical ventilation is applied. b) ${\lambda}_v$, depending on the air particle-concentration, reduces the dose somewhat within ${\lambda}_v$<1 $h^{-1}R range. However, the dose increases conversely, ${\lambda}_v$>1 $h^{-1}R range range. c) ${\lambda}{_{d}^{4}}$ reduces the dose linearly as ${\lambda}_v$ dose. Such dose(z-axis) sentivities are shown with three-dimensional plots whoes x,y-axes are combined 2out the 3 parameter${\lambda}_v{\lambda}_s,\;{\lambda}_d^s$.

• Journal of the Korean Society of Radiology
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• v.5 no.5
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• pp.231-235
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• 2011

Radium is rock or soil of crust or uranium of building materials and thorium after radioactivity collapse process are created colorless and odorless inert gas that accrue well in sealed space like mine or basement. It inflow to lung circulate respiratory organ and caused lung cancer because of deposition of lung or bronchial tubes. Radium sheath of medical institution treat person's life is possible big danger to professional regarding radioactivity who has much amount exposed radioactivity and weaker immune patient. so we do this test. Using measuring instrument at test is real time radium measuring instrument, Professional Continuous Radon monitor, and measuring places are basement first floor and second floor of two hospitals and measure from 10 a.m to 3 p.m. Measurement result of Professional Continuous Radon monitor is minimum 14.8 Bq/$m^3$ to maximum 70.3 Bq/$m^3$ and show domestic baseline below 148 Bq/$m^3$, effective dose-rate is minimum 0.296 mSv to maximum 1.406 mSv that show 2.4 mSv, 10~58.3% level, exposed radiation amount from nature radiation one year.

• Journal of Environmental Health Sciences
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• v.32 no.2 s.89
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• pp.140-148
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• 2006

Recently, indoor air quality (IAQ) in workplace, residential environments and schools has been concerned of people, scientists and related the public, and has recognized the health effects related to indoor air pollution. Therefore, this study was performed to investigate the characteristics of IAQ in 55 kindergartens, elementary school, middle schools, and high schools from June, 2004 to May, 2005 in Korea. We measured indoor air pollutants($PM_{10},\;CO_2$, HCHO, total bacteria colony(TBC), CO, radon, TVOCs, asbestos, and $O_3$), and physical factors(noise, temperature, relative humidity, and illumination) with necessary of management for IAQ in school. We classified into 5 kinds of the school by period since building completion, <1 year, 1-3 years, 3-5 years, and 5-10 years. The concentration of pollutants and the level of physical factors compared with standards and guidelines of IAQ on the Ministry of Environment, the Ministry of Health and Welfare, and the Ministry of Education and Human Resources Development. The major results obtained from this study were as follows. Temperature, relative humidity and illumination among the physical factors did not exceed the standards, but noise exceeded it. Asbestos and $O_3$ did not detect in surveyed classrooms. CO, TBC, TVOCs, and HCHO in kindergartens, TBC in elementary schools, TBC, TVOCs dnd HCHO in middle schools, and HCHO in high schools detected the standards. This study is conducted as a part of efforts to provide a foundational data for further relative researches on management of IAQ of school. Therefore, we suggest that country plan for management of IAQ in school should be established through long-term and continuous investigation for assessment on IAQ in school and health risk assessment for students.

• Environmental and Resource Economics Review
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• v.16 no.4
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• pp.873-900
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• 2007

Non-market valuation studies tend to assume that individual households have homogeneous preferences for a non-market good to value. However, since the preferences for non-market goods, especially environmental goods are more likely to be heterogeneous by nature, it may be more appropriate to assume heterogeneous preferences for non-market goods, which may in turn may lead to reduced biases in the WTP estimation. This study investigate the extent to which individual households have heterogeneous preferences for reduced concentrations of radon, a radioactive indoor air pollutant, for road safety, and for nuclear power safety. We also analyze the effect of heterogeneity assumption on the results of model and WTP estimation. Using the choice experiments and mixed logit models, we found that allowing for heterogeneous preferences improved model fitness and that there existed heterogeneous preferences for both reduced radon concentration and road safety, albeit not for nuclear power safety. The mean WTP for reduced radon concentrations and road safety increased by factors of 2.44 and l.74 respectively with the models allowing for heterogeneous preferences.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.17-25
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• 2016

In this study, the air quality of underground and overground railway stations was evaluated focusing on the degree of influence of the outside air quality. The measured components were particulate matter ($PM_{10}$), carbon dioxide ($CO_2$), carbon monoxide (CO), nitrogen dioxide ($NO_2$), formaldehyde (HCHO), ozone ($O_3$), total airborne bacteria (TAB), total volatile organic carbon (TVOC), and Radon (Rn), which are included in the maintenance standards and recommended standards of the Indoor Air Quality Management Act. Also, the indoor/outdoor concentration ratios of $PM_{10}$, $NO_2$, and $O_3$ were calculated to estimate the influence of the outdoor air quality. The concentrations of $PM_{10}$ HCHO, TVOC, $NO_2$, and Rn in the underground stations were found to be higher than those in the overground stations. These results indicate that the (present) generation of contaminants are caused by the indoor source of the underground station. The ozone concentration of the overground stations was higher than that of the underground stations, which indicates that the outdoor ozone concentration influenced that of the overground stations directly. Thus, methods of improving the IAQ should take into consideration the types of contamination.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.11
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• pp.1001-1010
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• 2010

The purpose of this study is to investigate the concentration levels of particle materials ($PM_{10}$, asbestos), gas materials ($CO_2$, CO, $NO_2$, HCHO, Rn, VOCs) and total suspended colony (TSC), and the correlations among these materials in indoor air quality of 54 multiple-use facilities and 15 public-use facilities of Gwangju. The highest mean concentration of $PM_{10}$ was $69.2\;{\mu}g/m^3$ at indoor parking place, followed by childcare facilities, large commercial building and subway station building. The highest mean concentration of CO was 2.7 ppm at indoor parking place and that of $CO_2$ was 604.1 ppm at medical service facilities. The highest mean concentration of $NO_2$ was 0.036 ppm at indoor parking place. The geomean concentration of HCHO was $3.6\;{\mu}g/m^3$ in all facilities and the highest was $631.8\;{\mu}g/m^3$ at art gallery. The geomean concentration of VOCs (5 species) was $24.14\;{\mu}g/m^3$ in all facilities and toluene was the highest material of $15.30\;{\mu}g/m^3$, followed by xylene, ethylbenzene, benzene and styrene. The highest mean concentration of TSC was $625.3\;CFU/m^3$ at jjimjilbang, followed by childcare facilities, medical service facilities and large commercial building. The highest of asbestos was 0.0072 each/cc at childcare facilities and that of radon was 1.41 pCi/L at art gallery. PM10 showed positive correlations to TSC with $R^2\0.5332$ by lognormal equation at childcare facilities. CO2 showed positive correlations to CO at childcare facilities and indoor parking place. Lognormal equation fitted to the VOCs data more than normal equation in all facilities.