• Particle and aerosol research
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• v.16 no.3
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• pp.65-72
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• 2020

In this study, the indoor fine dust concentration in an office of the Korea Knowledge Industry Center was measured for about 80 hours when the concentration of atmospheric PM_2.5 was very high. The effect of the operation of the air cleaner and the forced ventilation system on the indoor PM_2.5 was investigated, and the particle size distribution of the indoor and outdoor particles was analyzed. When forced ventilator and air purifiers were partially used, the indoor PM_2.5 concentrations were maintained between 27.7 ㎍/㎥ and 32.9 ㎍/㎥ when the atmospheric PM_2.5 was 127.7 ㎍/㎥ to 141.6 ㎍/㎥ during working hours. It is more effective to operate the air purifier without operating the forced ventilation system when the concentration of the PM_2.5 is high since the PM_2.5 penetrating the installed filter is continuously introduced indoor from the outside.

• Environmental and Resource Economics Review
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• v.31 no.1
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• pp.85-112
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• 2022

This study analyzed the influence of domestic and Chinese factors on fine dust(PM10 & PM2.5) in Korea by using the panel quantile regression. Daily analysis was conducted for 11 regions in Korea. For domestic factors, electricity demand and traffic volume, and for Chinese factors, interaction term of Chinese three cities' fine dust and the domestic west wind are used. As a result, the influence of domestic factors was different when the domestic fine dust concentration was high and low. When the fine dust concentration was low, electricity demand had a positive effect only on PM2.5, and didn't affect PM10 in the national analysis. In regional analysis, the amount of electricity demand had a significant effect on fine dust and ultrafine dust only in the capital area and Chungcheong. Electricity demand was found to significantly increase both PM2.5 and PM10 when it was high. On the other hand, it was confirmed that the Chinese factor always had a significant effect regardless of the concentration of PM10 and PM2.5. Therefore, in order to solve the problem of high concentration of fine dust, in addition to international cooperation, the reduction of PM2.5 generated by domestic thermal power generation should also be strengthened compared to the present.

• Journal of the Korean Data and Information Science Society
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• v.28 no.3
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• pp.473-481
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• 2017

It is well known that the air quality of 92% of the world is known to exceed the standard of WTO and the death caused by air pollution is almost 6 million per year. The $PM_{2.5}$ concentration in Korea is the second most serious among the OECD countries following Turkey. Since the $PM_{2.5}$ has a direct effect on the respiratory system, it has been actively studied in domestic and foreign countries. But current research on the $PM_{2.5}$ is limited in weather factor or air pollutants. In this paper, we consider the influence of spatial neighbor with weather factor or air pollutants using spatial panel model. We applied the proposed method to 25 borough of Seoul in Korea. The result shows a significant effect of spatial neighbor on the $PM_{2.5}$ concentration fields.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.4
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• pp.221-228
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• 2017

We proposed a novel method to remove PM2.5 dusts without HEPA filters aiming at applications in kitchens or enclosed work spaces generating PM2.5 at high concentrations. Many workers are exposed to PM2.5 owing to lack of air purification because the high replacement costs of HEPA filters make their application impractical. A key idea is to use the condensational growth of nanoparticles. Once particles grow to the size of a few micrometers, it is much easier to remove them because of their increased inertia. We developed and tested a prototype consisting of an air saturator (equipped with water spray nozzles), a condenser in which humid air was cooled down to make the particles grow, and a multi-impactor assembly for collecting the grown particles.

• Korean Journal of Remote Sensing
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• v.37 no.6_2
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• pp.1891-1900
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• 2021

Fine particulate matter (FPM; diameter ≤ 2.5 ㎛) is frequently found in metropolitan areas due to activities associated with rapid urbanization and population growth. Many adolescents spend a substantial amount of time at school where, for various reasons, FPM generated outdoors may flow into indoor areas. The aims of this study were to estimate FPM concentrations and categorize types of FPM in schools. Meteorological and chemical variables as well as satellite-based aerosol optical depth were analyzed as input data in a random forest model, which applied 10-fold cross validation and a grid-search method, to estimate school FPM concentrations, with four statistical indicators used to evaluate accuracy. Loose and strict standards were established to categorize types of FPM in schools. Under the former classification scheme, FPM in most schools was classified as type 2 or 3, whereas under strict standards, school FPM was mostly classified as type 3 or 4.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.10
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• pp.717-723
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• 2013

The Korea Ministry of Environment prepares some paticulate matter eliminate measures for national health protection, as the Paticulate Matter ($PM_{2.5}$) exceeds the standard at more than half of the monitoring posts installed in the nation's big cities. At the center of JeonJu, when measuring the ultrafine particles of inner car at the different driving conditions, at the condition of the Actuator of inner recirculation mode and the Blower of 2-speed, the reduction speed of the ultrafine particles is most fast and the concentration stays low. When the windows are opened during driving, outer pollutants enter the car and also inner paticulate matter flies in all direction, and the increase of passengers causes the scattering of the ultrafine paticles. As the filter for air cleaning, the using of polypropylene non-woven fabric (used commonly now) is most excellent, but for the removal of volatile organic substance as well as the paticulate matter, it is thought that the using of activated carbon fiber filter, carbon adsorbent, is even more excellent.

• Particle and aerosol research
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• v.15 no.1
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• pp.37-44
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• 2019

It is recommended for the public to stay at home and to close the doors and windows when a high-particulate-matter environment such as a yellow sand event occurs outside. However, there are lack of empirical studies describing how much outdoor PM infiltrates into a closed house and how much indoor PM an inhabitant is exposed to during the period. In this study, the $PM_{10}$ and $PM_{2.5}$ were measured at the kitchen in an apartment house by an optical particle counter for 3 days including a yellow sand event. The outdoor PMs and the outdoor wind speeds were referred from surrounding weather stations. We analyzed the penetration of $PM_{10-2.5}$ and $PM_{2.5}$ at the test house against the outdoor wind speed supposed corresponding to the change of air exchange rate. In addition, the effect of an indoor activity on change in the indoor PM was investigated. In result, the indoor $PM_{10-2.5}$ was very low even a yellow sand event occurred outside; rather, a contribution of indoor activities to increase in $PM_{10-2.5}$ was higher. In contrast, the indoor $PM_{2.5}$ fluctuated following the outdoor $PM_{2.5}$ trend at high wind speeds or remained almost constant at low wind speed.

• Journal of Convergence for Information Technology
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• v.11 no.8
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• pp.92-99
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• 2021

Light-scattering fine particulate matter monitors can measure particulate matter (PM) concentrations in every second and can be designed in a portable size. They can measure the concentrations of various PM sizes (PM_1.0, PM_2.5, PM_4.0 and PM₁₀) with a single sensor. They measure the number and size of particulate matters and convert them to weight per volume (concentration). These devices show a large error for asian dust. This paper proposes a scheme that compensates the PM_2.5 concenstration error for asian dust by multiple linear regression machine learning in light-scattering PM monitors. This scheme can be effective with only two or three types of PM sizes. The experimental results compare a beta-ray PM monitor of national institute of environmental research and a light-scattering PM monitor during a month. The correlation coefficient (R²) of theses two devices was 0.927 without asian dust, but it was 0.763 due to asian dust during the entire experimental period and improved to 0.944 by the proposed machine learning.

• Korean Journal of Remote Sensing
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• v.38 no.5_3
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• pp.863-872
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• 2022

Rare earth elements (REEs) have been used as one of power tracers for understanding geological and environmental changes due to their similar physico-chemical properties. In this study, we investigated the characteristics of rare earth elements in atmospheric particulates(PM_2.5) collected in Beijing and Gwangju during January 2018. The total concentrations of REEs in the Beijing samples were about 16X higher than those in Gwangju samples, and both samples are enriched in light REE than heavy REE, up to 8-10 times. The Post Archean Australian Shale (PAAS)-normalized pattern showed that both samples are enriched in Eu, Tb, and Er, and displayed positive Eu but negative Ce anomalies. The elemental correlations indicate that both samples originated from China desert and Loess plateau as well as cities surrounding Beijing. This study suggests that REEs in PM_2.5 can be used as a powerful proxy of revealing the difference between China and Korea, and provide basic information on the source and transport of PM_2.5.

• Proceedings of the Korea Information Processing Society Conference
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• 2019.05a
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• pp.491-492
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• 2019

최근, 한국에서는 사람들이 미세먼지로 많은 고통을 받고 있으며, 특히, 초미세먼지(PM2.5)의 경우에는 생성될 때, 화학적인 2차 반응에 의하여 생성되는 것으로 여겨지고 있다. 본 논문에서는 R에서 제공하는 기계학습 프로그램을 이용하여 초미세먼지를 예측하기 위한 실험을 진행하였다. R소프트웨어는 빅데이터 및 통계 분석을 위해서 많이 사용되고 있는 프로그램이다. 최근에는 인공지능의 기계학습을 위한 기능도 제공하고 있는데, 데이터 예측을 할 때, 사용하면 매우 유용하다.