• Elastomers and Composites
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• v.56 no.1
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• pp.1-5
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• 2021

Tire and road wear particles (TRWPs) were collected from road dust and thermogravimetric analysis (TGA) was performed to measure the content of tire wear particles (TWPs) in the TRWPs. The TGA thermograms of TRWPs showed two weight loss steps associated with polymer decomposition including weight loss after 480℃ which may be due to road wear particles. Different samples gave different TGA thermograms because the types and contents of the road wear particles attached to the TWPs should be different from each other, and each TWP might have different composition. The TGA results of the model asphalt pavement wear particles, with (volatile organics + polymers + carbon black) : ash = 33.5 : 66.5, was applied to the TRWP results, and the TWP contents of TRWPs were found to be 50-65%. The zinc oxide content in the rubber compound was negligible.

• IEMEK Journal of Embedded Systems and Applications
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• v.17 no.2
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• pp.93-100
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• 2022

In this paper, we propose a machine learning-based method for supporting resource management of IoT software platforms in a multi-modal sensing scenario. We assume that an IoT device installed with a oneM2M-compatible software platform is connected with various sensors such as PIR, sound, dust, ambient light, ultrasonic, accelerometer, through different embedded system interfaces such as general purpose input output (GPIO), I2C, SPI, USB. Based on a collected dataset including CPU usage and user-defined priority, a machine learning model is trained to estimate the level of nice value required to adjust according to the resource usage patterns. The proposed method is validated by comparing with a rule-based control strategy, showing its practical capability in a multi-modal sensing scenario of IoT devices.

• Annual Conference of KIPS
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• 2022.11a
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• pp.1009-1011
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• 2022

최근 미세먼지는 중대한 건강위험요소로 고려되고 있고, 미세먼지 취약계층은 이에 대한 적극적 대응이 필요하다. 그러나 현재의 대기환경지수는 세분화 되어있지 않아 본 논문에서는 위해성 평가와 GAM 모형을 기반으로 건강취약계층 대상을 위한 미세먼지 위험지수를 새롭게 개발하였다. 또한, 이에 따라 실내 및 실외활동을 추천하는 시스템을 구현함으로써 생활밀착형 스마트시티로 발돋움하도록 한다.

• Annual Conference of KIPS
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• 2022.11a
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• pp.14-16
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• 2022

세계보건기구에 의해 미세먼지가 1급 발암물질로 지정됨에 따라, 건강에 미치는 영향에 대한 관심이 커지고 있다. 성장기 학생들은 학교에서 오랫동안 머무르게 되며, 따라서 교내 미세먼지는 학생들의 건강에 미치는 영향이 매우 클 수 있다. 본 연구에서는 1년동안 대상 학교에서 수집한 미세먼지 관련 데이터 및 공개된 Air Korea, 기상청 데이터를 활용하여, LSTM 기반 미세먼지 예측 모델을 개발하였다. 수집한 데이터에서 일부 오류나 결측치가 있었지만, 이를 활용한 미세먼지 예측 정확도는 충분히 가치가 있다고 판단된다.

• Annual Conference of KIPS
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• 2023.05a
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• pp.90-91
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• 2023

대기오염에 대한 사회적 관심이 증가함에 따라 미세먼지 관련 IoT 가전제품의 수요가 증가하였다. 이에 따라 IoT 제품에서 수집되는 실내 데이터의 정확성을 높이기 위해 미세먼지 센서 외의 추가적인 센서를 사용하여 관측치를 예측하는 연구가 진행되고 있다. 하지만 기존 연구에서는 센서의 물리적 한계를 인공지능을 통하여 극복하려는 시도는 존재하지 않는다. 본 논문에서는 추가적인 센서를 사용하지 않고 단일 센서만을 사용하여 미세먼지 종류의 구분 가능성을 판단하고자 하며 이를 정확도 기반으로 비교 실험을 진행하여 가장 좋은 성능을 나타낸 딥러닝 기반 분류모델을 선정한다.

• Journal of Korean Society for Atmospheric Environment
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• v.31 no.5
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• pp.461-471
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• 2015

Base on emission factors derived from National Institute of Environmental Research, Particulate matter from combined cycle power plants (CCPPs) has been estimated to be a important source of $PM_{10}$. Generally there is no serious emission of particulate matter in CCPPs. because the fuel of them is natural gas. But emission gas after long shut down season has very high dust content. Therefore $PM_{10}$ emission rate is dependent on its operation mode. In this study, particulate dispersion study for new city near CCPPs complex has performed using CALPUFF model for three case. $PM_{10}$ concentration has big difference between normal operation and 2 case start-up condition after long shutdown. In normal operating conditions, daily $0.32{\sim}0.50{\mu}g/m^3$ influence on of the surrounding area. But when 1~2 aerobic high concentration discharged conditions, average concentration is higher about $9.2{\sim}34.1{\mu}g/m^3$ than normal operating conditions.

• Journal of The Korean Astronomical Society
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• v.36 no.1
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• pp.21-31
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• 2003

ASTRO-F /FIS will carry out all sky survey in the wavelength from 50 to 200 ${\mu}m$. At far infrared, stars and galaxies may not be good calibration sources because the IR fluxes could be sensitive to the dust shell of stars and star formation activities of galaxies. On the other hand, asteroids could be good calibration sources at far infrared because of rather simple spectral energy distribution. Recent progresses in thermal models for asteroids enable us to calculate the far infrared flux fairly accurately. We have derived the Bond albedos and diameters for 559 asteroids based on the IRAS and ground based optical data. Using these thermal parameters and standard thermal model, we have calculated the spectral energy distributions of asteroids from 10 to 200 ${\mu}m$. We have found that more than $70\%$ of our sample asteroids have flux errors less than $10\%$ within the context of the best fitting thermal models. In order to assess flux uncertainties due to model parameters, we have computed SEDs by varing external parameters such as emissivity, beaming parameter and phase integral. We have found that about 100 asteroids can be modeled to be better than $5.8\%$ of flux uncertainties. The systematic effects due to uncertainties in phase integral are not so important.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.522-525
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• 2008

최근 세라믹 막은 우수한 화학적, 열적 안정성으로 기체 분리 공정에 각광을 받아 왔다. 특히 혼합기체에서 고 순도의 수소를 분리해 내는 기술은 연료전지 공정에서 화학 에너지를 전기화학 에너지로 전환시키는데 중요한 역할을 차지한다. 본 연구에서는MTES 템플레이팅 막을 이용하여 이 막 공정의 흡착 및 투과 특성을 규명하고, 이성분 혼합기체에서 고 순도의 수소를 추출해 낼 수 있는 최적 조건을 도출해 내었다. 또한, 기체 분리 거동을 살펴보기 위해 Gproms Dynamic Simulator를 이용하였으며, 이때 기체상의 물질전달을 모사하기 위해 Dust Gas Model(DGM)을, 표면 확산 거동을 모사하기 위해 Generalized Stefan-Maxwell(GSM)식을 적용하였다. 이를 통해 평형론적 흡착 뿐 아니라 속도론적 흡착을 동시에 적용할 수 있게 하였다. MTES 템플레이팅 막의 흡착 및 분리능을 규명하기 위해 본 연구에서는 혼합기체의 투과, 분리 실험이 선행되었다. 실험 조건은 온도범위 323$\sim$473 K, 압력범위 0$\sim$7 atm에서 수행되었으며, 혼합기체는2성분으로 수소-메탄, 수소-이산화탄소, 수소-질소로 기체의 구성비는 각각 50:50 이다. 본 연구를 통해 각 혼합 기체들이 정상상태에 도달하는 시간과 분리능을 계산해 내었으며, 이 분리능을 다시 온도와 압력에 따른 결과로 분석하여 어느 조건에서의 수소 분리도가 최고치를 보이는지를 규명했으며, 시뮬레이션과 비교,대조하여 예측도를 검사하였다.

• Journal of Korean Society for Atmospheric Environment
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• v.16 no.5
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• pp.445-451
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• 2000

To estimate dry deposition flux of 12 elements in aerosols, aerosol particles were sampled by a low-pressure impactor(LPI) and a dust jar. The concentrations of 12 elements in aerosol particle and dry deposition were analyzed by a PIXE analysis using as a 2.0 MeV-proton beam. The mean dry deposition velocities of 12 elements were estimated by ranges of 0.74∼2.62 cm/sec. The results showed that the highest value was 3.26 cm/sec for Ca and the lowest value 0.74 cm/sec for Fe. The dry deposition flux for elements was calculated as a function of particle size by 1-step method and 12-step method. In this work, dry deposition velocities were computed with the two existing models; the coarse-particle fraction(4∼30 mm diameter) using the dry deposition velocity model of the Noll and Fang(1998) and the fine-particle fraction (0.05∼4mm diameter) using the Shemel and Hodgson(1980) model. The ratios of the mean calculated/measured fluxes were 3.59 for 1-step method and 0.60 for 12-step method respectively.

• Journal of Environmental Science International
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• v.22 no.8
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• pp.1043-1052
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• 2013

This study was conducted to investigate the correlations between the $PM_{10}$ concentration trend and meteorological elements in the Gimhae region and analyze the transportation routes of air pollutants through back-trajectory analysis. Among the air quality measuring stations in the Gimhae regions, the $PM_{10}$ concentration of the Sambangdong station was higher than that of the Dongsangdong station. Also, an examination of the relationships between $PM_{10}$ concentration and meteorological elements showed that the greater the number of yellow dust occurrence days was and the lower the temperature and precipitation were, the higher the $PM_{10}$ concentration appeared. Furthermore, a cluster analysis through the HYSPLIT model showed that there were 4 clusters of trajectories that flowed into the Gimhae region and most of them originated in China. The meteorological characteristics of the four clusters were analyzed and they were similar to those of the air masses that influence South Korea. These analyses found that meteorological conditions affect the $PM_{10}$ concentration.