• 한국환경보건학회지
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• 제47권4호
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• pp.339-355
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• 2021

Background: Particulate matter (PM₁₀, PM_2.5) and black carbon contribute to poor air quality in urban areas, and can also affect indoor environments. Exposure to PM can be associated with respiratory and lung diseases. Objectives: This study investigated the indoor and outdoor concentration distribution patterns of PM₁₀, PM_2.5, and black carbon at an apartment building, a typical residential space in the metropolitan areas of South Korea, by season, day of the week (weekday vs. weekend), and time of the day. It aims to obtain foundational data for the effective management of pollutants and investigate the difference in pollution levels between indoor and outdoor environments. Methods: Indoor and outdoor concentrations of PM and black carbon were measured at an apartment building located in Namyangju, Gyeonggi-do Province, using dust sensors and an Aethalometer AE51 (AethLabs, San Francisco, CA, USA) over the course of a year from June 2020 to May 2021. The concentration distribution patterns were analyzed by season and time of day. Results: PM₁₀ and PM_2.5 concentrations in the outdoor environment were higher than those in the indoor environment, regardless of the season. By contrast, the indoor black carbon concentration was higher than that in the outdoor environment during summer and autumn. The concentrations of PM₁₀, PM_2.5 and black carbon were found to be higher on weekdays than during weekends, especially during rush hour, with concentrations of 25.92~56.58 ㎍/m³, 21.12~44.82 ㎍/m³, 0.63~3.40 ㎍/m³. Conclusions: The outdoor concentrations of PM₁₀, PM_2.5, and black carbon were higher during the weekdays, especially during rush hour, than during weekends. This study is expected to provide basic data for the health management of apartment occupants because it is measured over a period of more than one year.

• Asian Journal of Atmospheric Environment
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• 제5권4호
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• pp.237-246
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• 2011

To explore the sources of carbonaceous material in the airborne particulate matter (PM), comprehensive PM sampling was performed (3 to 14 January 2010) at a traffic hot spot site (HS), Farm Gate, Dhaka using several samplers: AirMetrics MiniVol (for $PM_{10}$ and $PM_{2.5}$) and MOUDI (for size fractionated submicron PM). Long-term PM data (April 2000 to March 2006 and April 2000 to March 2010 in two size fractions ($PM_{2.2}$ and $PM_{2.2-10}$) obtained from two air quality-monitoring stations, one at Farm Gate (HS) and another at a semi-residential (SR) area (Atomic Energy Centre, Dhaka Campus, (AECD)), respectively were also analyzed. The long-term PM trend shows that fine particulate matter concentrations have decreased over time as a result of government policy interventions even with increasing vehicles on the road. The ratio of $PM_{2.5}/PM_{10}$ showed that the average $PM_{2.5}$ mass was about 78% of the $PM_{10}$ mass. It was also found that about 63% of $PM_{2.5}$ mass is $PM_1$. The total contribution of BC to $PM_{2.5}$ is about 16% and showed a decreasing trend over the years. It was observed that $PM_1$ fractions contained the major amount of carbonaceous materials, which mainly originated from high temperature combustion process in the $PM_{2.5}$. From the IMPROVE TOR protocol carbon fraction analysis, it was observed that emissions from gasoline vehicles contributed to $PM_1$ given the high abundance of EC1 and OC2 and the contribution of diesel to $PM_1$ is minimal as indicated by the low abundance of OC1 and EC2. Source apportionment results also show that vehicular exhaust is the largest contributors to PM in Dhaka. There is also transported $PM_{2.2}$from regional sources. With the increasing economic activities and recent GDP growth, the number of vehicles and brick kilns has significantly increased in and around Dhaka. Further action will be required to further reduce PM-related air pollution in Dhaka.

• 한국운동역학회지
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• 제29권2호
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• pp.71-77
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• 2019

Objective: The aim of this study was to investigate postural control strategies on smart phone use during gait in over 50-year-old adults. Method: 8 elderly subjects (age: $55.5{\pm}3.29yrs$, height: $159.75{\pm}4.20cm$, weight: $62.87{\pm}8.44kg$) and 10 young subjects (age: $23.8{\pm}3.19yrs$, height: $158.8{\pm}5.97cm$, weight: $53.6{\pm}5.6kg$) participated in the study. They walked at a comfortable pace in a gaitway of ~8 m while: 1) reading text on a smart phone, 2) typing text on a smart phone, or 3) walking without the use of a phone. Gait parameters and kinematic data were evaluated using a three-dimensional movement analysis system. Results: The participants read or wrote text messages they walked with: slower speed; lesser stride length and step width; greater flexion range of motion of the head; more flexion of the thorax in comparison with normal walking. Conclusion: Texting or reading message on a smart phone while walking may pose an additional risk to pedestrians' safety.

• 한국대기환경학회지
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• 제19권2호
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• pp.231-245
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• 2003

Hourly PM$_{10}$ concentrations measured at 11 sites in Seoul and 10 sites in the large cities over South Korea for the period from March 1995 to February 2000 are analyzed to examine annual trend and monthly variations of the PM$_{10}$ concentrations. Further analysis has been carried out by using the one year data from March 1999 to February 2000 to see the seasonal variation, diurnal variation and weekly variation of the seasonally averaged PM$_{10}$ concentrations at each site. Weekly variations of the CO concentrations at the same sites for the same one year period are compared with that of the PM$_{10}$ concentration. There is no significant annual trend in the variation of the PM$_{10}$ concentration at all the sites analyzed. The seasonal and monthly mean concentrations show a minimum concentration in summer and alternative maximum concentration in spring and winter for most sites. The diurnal variation of the seasonally averaged mean PM$_{10}$ concentrations is strongly affected by traffic loads and meteorological conditions. The weekly variation of seasonal averaged concentrations of CO and PM$_{10}$ shows a high concentration for weekdays in spring, autumn and winter while high concentration for weekends in summer.nds in summer.

• 한국대기환경학회지
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• 제29권2호
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• pp.186-198
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• 2013

The present work is an attempt to improve the performance of a regional air quality model by means of liking it with a global chemistry transport model. The global chemical transport model of GEOS-Chem is used to provide BC (Boundary Condition)s which reflect temporal and spatial variations at boundaries of regional chemical transport model of CMAQ over East Asia. First, GEOS-Chem outputs are evaluated by comparing predicted concentrations with observed monthly data of gas phase species and secondary inorganic aerosols from EANET (Acid Deposition Monitoring Network in East Asia) sites. The results show that predicted PM10 concentrations are in good agreement with the observations. This implies that GEOS-Chem outputs could be used to provide BCs to CMAQ. Simulated daily and monthly mean PM10 concentrations of CMAQ with the linkage of GEOS-Chem's BCs and constant BCs are then evaluated by comparing predicted concentrations with observations at API (Air Pollution Index) sites in China as well as EANET sites in Korea. CMAQ with the GEOS-Chem outputs improves model simulation in depicting observed PM10 concentrations comparing with those with constant BCs. It is also found that influence of aerosol species are largely dependent on the BCs over East Asia and Korea. Mean biases between simulated versus observed daily and monthly mean concentrations of PM10 with the GEOS-chem were improved by 1~8 ${\mu}g/m^3$ in China region, 3.26 ${\mu}g/m^3$ in Korea.

• 대한원격탐사학회지
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• 제28권4호
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• pp.449-458
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• 2012

본 연구에서는 덕적도와 제주도에서 2005년 10월 15일부터 2007년 10월 24일 까지 9차례에 걸친 집중 관측기간 동안 포집된 PM2.5의 질량 농도 자료와 Moderate-resoultion Imaging Spectroradiometer (MODIS) 인공위성 관측자료로 분석된 대기 에어러솔 광학두께(AOT; Aerosol Optical Thickness) 자료로부터 지역 대기 중 미세 입자의 농도 변화 특성 및 대기질 감시를 위한 인공위성 자료의 활용 가능성을 분석하였다. 전체 관측 기간 중 PM2.5의 일 평균 농도는 덕적도에서는 $25.61{\pm}22.92{\mu}g/m^3$, 제주도에서는 $17.33{\pm}10.79{\mu}g/m^3$으로 변화가 크게 나타났으며, 황사가 발생한 2006년 4월 8일에는 덕적도와 제주도에서 각각 최대값 $188.89{\mu}g/m^3$과 $50.46{\mu}g/m^3$를 기록하였다. 또한 두 지역의 MODIS AOT 값은 $0.79{\pm}0.81$(덕적도), $0.42{\pm}0.24$(제주도)였으며, AOT의 최대값은 PM2.5와 마찬가지로 황사현상이 발생한 2007년 4월 8일에 3.73(덕적도), 1.14(제주도)로 나타났다. 그리고 지상에서 관측된 PM2.5 농도의 공간 분포 양상을 파악하기 위하여 MODIS AOT와 PM2.5의 상관관계 분석결과, 덕적도는 0.85, 고산은 0.06으로서 비교적 에어러솔의 영향을 많이 받는 덕적도가 고산보다 높은 상관계수 값을 나타내었다. 이러한 상관관계를 근거로 하여 도출된 1차 선형회귀 방정식으로부터 MODIS AOT값을 PM2.5로 환산한 결과는 인공위성 자료로부터 대기환경 감시를 가능케 하는 수단이 될 수 있어 유용할 것이다.

• Journal of Preventive Medicine and Public Health
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• 제20권1호
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• pp.97-113
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• 1987

This study was carried out to know physical growth and development, physical and nutritional indices and body fat weight and so forth by semi-longitudinal research method to measure body height, body weight, chest girth and sitting height of 260 of general high school and 306 of vocational high school 3rd grade students who are living in Seoul and born from 1966 March 1st to 1967 Feb.28th. The results are as follows: 1) Physical growth and development Growth in terms of body height showed one step straight linear development, andthat of body weight showed two step straight linear development in each section in high school. The age of cross over between two sexes of general high school students was between 10.6 to 12. 3 years in body height, between 10.8 to 13 years in body weight, between 11.2 to 14.6 years in chest girth and between 10 to 13 years in sitting height. The age of cross over between two sexes of vocational high school students was between 10.5 to 12.5 years in body height, between 10.5 to 12.5 years in body weight, between 10.5 to 12.5 years in chest girth and between 10.5 to 12.5 years in sitting height. In this periods, female group was superior to male group and after that male group was superior to female group again. The growth of vocational school students was superior to that of general school students in both sexes in terms of body height and body weight significantly. 2) Physical growth and nutritional indices In all cases of relative body weight, relative chest girth and relative sitting height, it was found to be increasing thereafter with advancing ages. In cases of $R{\"{o}}hrer$ index and Kaup index, it was found to be reaching to normal state thereafter with advancing ages. In each case of Vervaeck and Pelidisi index, it was found to be increasing and reaching to normal state thereafter with advancing ages. 3) Total body fat by vital measuring method Average values of body surface area, body volume and body density are measured indirectly by using the body height and body weight as Table 12, 13 and 14. The rate of body fat weight of general high school students was from minimum $11.96{\pm}3.53%(3.33{\pm}1.10kg$) to maximum $18.25{\pm}6.46%(9.08{\pm}2.01kg$) in male and from $25.88{\pm}3.62%(7.96{\pm}0.78kg$) to $43.00{\pm}7.22%(12.91{\pm}1.21kg$) in female. The rate of body fat weight of vocational high school students was from minimum $11.20{\pm}2.88%(3.32{\pm}1.13kg$) to maximum $17.16{\pm}5.88(10.83{\pm}3.16kg$) in male and from minimum $25.11{\pm}2.26%(7.91{\pm}0.89kg$) to maximum $42.16{\pm}7.96%(13.22{\pm}1.75kg$) in female.

• 에너지공학
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• 제26권4호
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• pp.45-56
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• 2017

Coal power plants produce electricity for the nation's power grid, but they also produce more hazardous air emissions than any other industrial pollution sources. The quantity is staggering, over 386,000 tons of 84 separate hazardous air pollutants spew from over 400 plants in 46 states. In South Korea also, annual coal ash generation from coal-fired power plants were about 6 million tons in 2015. Pollutants containing particulate matter 10, 2.5 (PM10, PM2.5), heavy metals and dioxins from coal-fired power plant. The emissions threaten the health of people who live near these power plants, as well as those who live hundreds of miles away. These pollutants that have long-term impacts on the environment because they accumulate in soil, water and animals. The present study is to investigate the physical and chemical characteristics of coal-fired power plant fly ash and bottom ash contains particulate matter, whose particulate sizes are lower than $PM_{10}$ and $PM_{2.5}$ and heavy metals. There are wide commercial technologies were available for monitoring the PM 2.5 and ultra-fine particles, among those carbonation technology is a good tool for stabilizing the alkaline waste materials. We collected the coal ash samples from different coal power plants and the chemical composition of coal fly ash was characterized by XRF. In the present laboratory research approach reveals that potential application of carbonation technology for particulate matter $PM_{10}$, $PM_{2.5}$ and stabilization of heavy metals. The significance of this emerging carbonation technology was improving the chemical and physical properties of fly ash and bottom ash samples can facilitate wide re use in construction applications.

• Journal of the Korean Data and Information Science Society
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• 제26권2호
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• pp.289-299
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• 2015

본 연구는 PM10 농도에 대한 계량치 예측모형 개발을 목적으로 한다. 세 종류의 자료 (기상관측 자료, 세계기상통신망 중국 관측자료, 대기질 화학수치모델자료)를 예측인자로 사용하였으며, 일일 단기예보 시스템에 쉽게 적용할 수 있도록 시간자료를 일자료로 변환하였고 시차변환을 수행하였다. 상관분석과 다중공선성 진단을 통하여 예측인자를 선택하고 두 종류의 모형 (중회귀모형, 문턱치 회귀모형)을 각각 적합하였다. 모형 안정성 검사를 위하여 모형검증을 수행하였으며, 전체자료를 사용하여 모형을 재추정한 후 예측치와 관측치 사이의 산점도와 시계열그림, RMSE, 예측성 평가측도를 작성 및 산출하여 두 모형을 비교하였다. 문턱치 회귀모형의 예측력이 고농도 PM10예측에서 다소 우수한 결과를 보였다.

• 한국방사선학회논문지
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• 제10권7호
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• pp.495-502
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• 2016

본 연구는 일개 종합병원 내 방사선 종사자의 피폭선량과 그에 따른 혈액검사를 일반인의 혈액검사결과와 비교하여 방사선피폭의 영향을 분석하였다. 대조군과 방사선 종사자군의 혈액검사 결과 모든 항목 평균 값은 정상범위에 포함되어 있었다. 호산구의 경우 방사선 종사자가($2.52{\pm}1.79%$) 대조군($2.92{\pm}1.39%$)에 비하여 낮으며 유의함을 나타내었다. 방사선 작업 종사기간에 따른 종사자군과 대조군의 혈액학적 검사결과 평균값은 백혈구, 혈소판, 임파구, 단핵구, 호염기구가 전체 평균에서 종사자군이 높은 값을 나타내었고, 20년 이상 종사자에서 대조군에 비하여 백혈구, 단핵구는 낮고, 혈소판은 높은 값을 나타내었으며, 10년 이하 종사자에서 호염기구가 대조군에 비해 낮은 값을 나타내었으나 전체 수치의 통계적 유의성은 없었다. 방사선 종사자의 4년간(2012년~2015년) 누적선량에 따른 검사항목별 평균차이에서 5.0 mSv 초과 종사자가 백혈구 평균값에서 대조군 및 5.0 mSv 이하 피폭군에 비하여 낮은 값을 나타내었고, 적혈구($4.61{\pm}0.53$), 적혈구용적률($41.51{\pm}4.07$) 및 호산구($1.74{\pm}1.14$)는 대조군의 적혈구($4.91{\pm}0.38$), 적혈구용적률($43.97{\pm}3.40$), 호산구($2.92{\pm}1.39$)와 저선량 피폭자의 검사결과에 비하여 유의하게 낮은 값을 나타내었다. 0.5~1.0 mSv 피폭 종사자의 혈색소($13.93{\pm}1.75$)가 대조군($14.90{\pm}1.29$) 및 타 피폭자에 비하여 유의하게 낮은 값을 나타내었다.