• 한국산업보건학회지
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• 제18권4호
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• pp.262-270
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• 2008

This study was conducted to measure concentrations of particulate matter ($PM_{10}$, $PM_{2.5}$) and endotoxin in thirty public facilities (7 elderly-care facilities, 4 hypermarkets, 4 university hospitals, 7 child-care facilities, 4 subway stations and 4 bus terminals) from September 2004 to February 2007 in Seoul and Gyeonggi-do province. $PM_{10}$ or $PM_{2.5}$ was measured with glass fiber filter and mini volume air sampler for 6 to 8 hours in indoor and outdoor of the facilities and expressed as ${\mu}g/m^3$. After weighing the filter, endotoxin was analyzed by Limulus Ameobocyte Lysate method ($EU/m^3$). $PM_{10}$ in indoor air was higher (GM and GSD was 78.00 and $1.92\;{\mu}g/m^3$, respectively) than the outdoor air (GM and GSD was 60.70 and $2.23\;{\mu}g/m^3$, respectively, I/O=1.28). All measurements was not exceeded the national maintenance standard. Elderly-care and child-care facilities showed relatively higher concentrations ($83.27\;{\mu}g/m^3$ and $81.75\;{\mu}g/m^3$; I/O=2.01 and 1.19, respectively) than hypermarkets or university hospitals. The highest PM2.5 was seen in child-care facilities ($62.15\;{\mu}g/m^3$, I/O=2.42). The I/O of the endotoxin in the PM10 and the $PM_{2.5}$ was exceeded 1.0 (1.37 and 1.57, respectively). Indoor $PM_{10}$ was affected by user/day and humidity, and endotoxin in the PM10 was affected by temperature. In conclusion, elderly- and child-care facilities are high priority facilities to be improved indoor air quality.

• 한국환경보건학회지
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• 제36권5호
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• pp.402-410
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• 2010

The objectives of this study were to evaluate the air quality surrounding an indoor swimming pool, to estimate the cancer risk based on the airborne exposure to trihalomethanes (THMs), and to examine the ventilation efficiency by Computational Fluid Dynamics (CFD). Chlorine and THMs were measured poolside, and in the staff room and reception area. The indoor swimming pool was modeled using the Airpak program, with ventilation drawings and actual survey data. Temperature, flow and mean age of the air were analyzed. Levels of chlorine poolside, and in the staff room, and reception area were $203\;{\mu}g/m^3$, $5\;{\mu}g/m^3$, and $10\;{\mu}g/m^3$, respectively. Chloroform was the dominant THM in all sampling sites and mean concentrations were $16.30\;{\mu}g/m^3$, $0.51\;{\mu}g/m^3$, and $0.06\;{\mu}g/m^3$ poolside, in the staff room and reception area, respectively. Bromodichloromethane and Dibromochloromethane levels were respectively estimated as $10.3\;{\mu}g/m^3$ and $1.7\;{\mu}g/m^3$ poolside, $1.3\;{\mu}g/m^3$ and $0.1\;{\mu}g/m^3$ in the staff room, and were not detected in the reception area. The cancer risks from inhalation exposure to THMs were estimated between $3.37{\times}10^{-7}$ and $1.84{\times}10^{-5}$. A short circulation phenomenon was observed from the supply air vents to the exhaust air vents located in the ceiling. A high temperature layer was formed within one meter of the ceiling, and a low temperature layer was formed under this layer due to the low velocity and high temperature of the supply air, and the improper locations of the supply air vents and exhaust air vents. The stagnation was evident at the above adult pool and the mean age of the air was 22 minutes. Disinfection by-products in the indoor swimming pool were present in higher concentrations than in the outdoor air. In order to increase the removal of pollutants, adjustment was required of the supply air volume and the supply/exhaust position.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2018년도 춘계학술대회
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• pp.536-539
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• 2018

본 논문에서는 심층 학습을 이용하여 주변 환경 정보를 분석하고 이후 환경 정보 변화를 예측해 사용자에게 적합한 환경을 제공하는 시스템을 제안한다. 생활의 수준이 향상되면서 삶의 질의 향상에 대한 관심도 높아지고 있다. 특히 최근 황사, 스모그, 미세먼지, 초미세먼지 등의 발생으로 대기질이 악화되자 실외공기뿐 아니라 실내공기의 질 역시 심각한 문제로 대두되었다. 환기의 부족, 화학 물질 사용 등으로 인해 실내 오염이 증가하는 상황은 실내 생활의 비중이 높은 현대인들에게는 심각한 문제이다. 이러한 실내 대기 오염을 해결하기 위해서 센서를 통해 대기질의 상태를 측정하고 적정 온도, 습도를 유지하는 시스템이 제안되었다. 그러나 기존 시스템은 대기 환경 정보의 대부분을 센서에만 의존하여 다양한 사용자에게 적용하는데 어려움이 있다. 본 논문에서 제안하는 시스템은 센서를 통해 수집한 실내 오염 정보를 심층 학습을 이용해 분석하여 실내 환경을 예측한다. 그리고 예측된 실내 환경을 모델링하여 본 시스템에 학습시킨 후 사용자에게 적합한 환경을 제안한다. 이후, 시스템은 사용자에게 제안된 환경을 최적의 환경 조성이 가능하도록 사용자로부터 피드백을 받고, 이를 재학습하는 과정을 반복한다.

• 한국환경보건학회지
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• 제47권5호
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• pp.410-424
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• 2021

Background: Subway stations have the characteristics of being located underground and are a representative public-use facility used by an unspecified number of people. As concerns about indoor air quality (IAQ) increase, various management measures are being implemented. However, there are few systematic studies and cases of long-term continuous measurement of underground station air quality. Objectives: The purpose of this study is to analyze changes and factors influencing IAQ in subway stations through real-time continuous long-term measurement using IoT-based IAQ sensing equipment, and to evaluate the IAQ improvement effect of a bio-filter system. Methods: The IAQ of a subway station in Seoul was measured using IoT-based sensing equipment. A bio-filter system was installed after collecting the background concentrations for about five months. Based on the data collected over about 21 months, changes in indoor air quality and influencing factors were analyzed and the reduction effect of the bio-filter system was evaluated. Results: As a result of the analysis, PM₁₀, PM_2.5, and CO₂ increased during rush hour according to the change in the number of passengers, and PM₁₀ and PM_2.5 concentrations were high when a PM warning/watch was issued. There was an effect of improving IAQ with the installation of the bio-filter system. The reduction rate of a new-bio-filter system with improved efficiency was higher than that of the existing bio-filter system. Factors affecting PM_2.5 in the subway station were the outdoor PM_2.5, platform PM_2.5, and the number of passengers. Conclusions: The IAQ in a subway station is affected by passengers, ventilation through the air supply and exhaust, and the spread of particulate matter generated by train operation. Based on these results, it is expected that IAQ can be efficiently improved if a bio-filter system with improved efficiency is developed in consideration of the factors affecting IAQ and proper placement.

• 한국전자통신학회논문지
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• 제16권2호
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• pp.271-278
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• 2021

본 논문은 외부환경을 인식하고 오염도에 따라 자동으로 오염물질을 제거하는, 스마트 필터 시스템의 구현에 관한 연구이다. 최근 실내외 공간에서 다양한 오염물질의 발생은 인체에 악영향을 미치고 있으며 특히 대기 중에서 발생되는 다양한 미세먼지는 밀폐된 주거 공간이나 사무공간에서 심해진다. 환기 등을 통해 일시적인 공기질 오염도를 낮출 수는 있으나 미세먼지 변화를 실시간적으로 대응하는 것이 어려워 가정이나 산업체와 같이 다수의 인력이 상주하는 공간에서 이와 같은 문제점은 심각해진다. 따라서 거주 공간의 내부의 미세먼지 농도를 실시간적으로 측정하고, 외부와의 자동 환기를 통해, 실내 환기의 오염농도를 저감시킬 필요성이 있다. 이와 같은 문제점을 개선하기 위하여, 본 논문에서는 외부환경 인식용 스마트 필터 시스템에 대한 구현을 제안하고자 한다. 실내외부의 공기질을 자동으로 측정하고, 오염물질을 제거하는 스마트 필터 시스템에 대한 구조를 설계하고 기능을 구현하였으며, 시제품을 제작하여 동작성을 확인하였다. 최종적으로는 스마트 필터 시스템의 미세먼지 문제 해결에 대한 효용성을 검토하였다.

• 한국환경보건학회지
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• 제50권1호
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• pp.16-24
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• 2024

Background: Indoor PM_2.5 concentrations in residential houses can be affected by various factors depending on the season. This is because not only do the climate characteristics depend on the season, but the activity patterns of occupants are also different. Objectives: The purpose of this study is to compare factors affecting indoor PM_2.5 concentrations in apartments and detached houses in Daegu according to seasonal changes. Methods: This study included 20 households in Daegu, South Korea. The study was conducted during the summer (from July 10 to August 10, 2023) and the autumn (from September 11 to October 9, 2023). A sensor-based instrument for PM_2.5 levels was installed in the living room of each residence, and measurements were taken continuously for 24 hours at intervals of one minute during the measurement period. Based on the air quality monitoring system data in Daegu, outdoor PM_2.5 concentrations were estimated using ordinary kriging (OK) in Python. In addition, the indoor activities of the occupants were investigated using a time-activity pattern diary. The affecting factors of indoor PM_2.5 concentration were analyzed using multiple regression analysis. Results: Indoor and outdoor PM_2.5 concentrations of the residences during summer were 15.27±11.09 ㎍/m³ and 11.52±7.56 ㎍/m³, respectively. Indoor and outdoor PM_2.5 concentrations during autumn were 13.82±9.61 ㎍/m³ and 9.57±5.50 ㎍/m³, respectively. The PM_2.5 concentrations were higher in summer compared to autumn both indoors and outdoors. The primary factor affecting indoor PM_2.5 concentration in summer was occupant activity. On the other hand, during the autumn season, the primary affecting factor was outdoor PM_2.5 concentration. Conclusions: Indoor PM_2.5 concentration in residential houses is affected by occupant activity such as the inflow of outdoor PM_2.5 concentration, cooking, and cleaning, as found in previous studies. However, it was revealed that there were differences depending on the season.

• 한국의료질향상학회지
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• 제7권1호
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• pp.72-89
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• 2000

Background : Various types of protective footwear have been used to minimize bacterial contamination in operating rooms. In recent years, debate has arisen concerning the need for use of such protective footwear. This study was designed to provide useful data about choosing shoes most suitable for the surgical environment. Methods : Between November, 1999 and January, 2000, we performed this experimental study by comparing effect of three types of shoes (i.e., disposable shoescover, operating room-restricted shoes, and ordinary shoes) on bacterial contamination of operating rooms equipped with two different ventilation systems (i.e., high air-change, low air-change) respectively. Data were collected during two- hour sham operations in which subjects and their activities were strictly standardized. Bacterial flora were sampled from the study area floor and air colony counts were measured. Results : In experiments involving high air-change ventilation system, there was a significant difference of floor contamination between three types of shoes, but no difference of air contamination. Under low air-change system, there was a significant difference of both floor and air contamination between three types of shoes. Conclusion : The results show that protective footwear would be unnecessary in the operating room with high air-change ventilation system, but it is important to choose suitable shoes carefully under low air-change system. Therefore, the use of outdoor shoes can be considered under high air-change system, but it would seem sensible to apply their first use in less bloody operations at the day surgery center or out-patient department to prevent transfer of body fluid into the outside environment.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2002년도 춘계학술대회 논문집
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• pp.555-560
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• 2002

Subway has been used one of major public transportations because of overpopulation and heavy traffic problems in the metropolitan areas. In this study, continuous date of PM-10(particles with aerodynamic diameter < 10$\mu\textrm{m}$) and heavy metal concentration measurements for autumn and winter period were analysed. These measurements have been carried out at the outdoor, concourse, platform, tunnel. The study results showed that the average seasonal concentration of PM-10 particles were 181.01$\mu\textrm{g}$/㎥ in autumn and 129.03$\mu\textrm{g}$/㎥ in winter, respectively. The concentration of Fe, Cu showed the largest peak concentrations during the respective season.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2009년도 추계학술발표대회 논문집
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• pp.123-129
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• 2009

In these days, the green building movement caused by the energy crisis is increasing, passive design is getting mere and more attention as it provides many possibilities for energy conservation. Moreover, with the increasing social intention for healthy life, the demand for indoor air Quality is increasing in Korea. As result, the ventilation system which can provide the sound outdoor air constantly has been obliged in Korea. So, the hybrid system which using natural power and mechanical power and makes up for the shortage of mechanical and natural ventilation attracts people's attention in Korea. As a hybrid ventilation system, in this study, the stack effect driven hybrid ventilation system in high-rise residential building will be suggested. And in this paper, the theoretical review for hybrid ventilation system suggested in this study will be addressed. Especially, the characteristics of pressure distribution and airflow caused by stack effect in high-rise residential building and the possibility of natural ventilation as results of stack effect will be described.

• 대한건축학회논문집:구조계
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• 제34권12호
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• pp.57-63
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• 2018

The purpose of this study was to confirm the effects of flush-out on the reduction of Volatile Organic Compounds(VOCs) concentration in newly built residential buildings. The field measurements were conducted in two complexes of multi-residential buildings which are located suburban areas of Seoul. About three samples of residential buildings were selected in the field measurements. Two samples, B and C, had been flush-out with outdoor air more than seven days. The sample A was maintained at same condition during the flush-out because of the comparison. The indoor concentrations of VOCs in the three samples were measured at three times, before, during, and after flush-out. From the field measurements, it was confirmed that two samples' indoor VOCs' concentrations were considerably decreased after the flush-out comapred with those of the sample A in which the flush-out was not conducted. The decreases of indoor VOCs concentrations were corresponding to about 50% ~ 92% of the concentrations of before. Through the reviews for the previous studies, it was also found that the reduction effects of the flush-out is similar with the those of the bake-out which were reported in the previous studies.