• 천문학회보
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• 제37권1호
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• pp.80.2-80.2
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• 2012

We firstly present the unified Far-UV continuum map of the Taurus-Auriga-Perseus (TPA) complex, one of the largest local associations of dark cloud located in (l, b)=([152,180], [-28, 0]), by merging both FIMS and GALEX. The FUV continuum map shows that dust extinction correlate well with the FUV around the complex. It says strong absorption in the dense Taurus cloud and Auriga cloud. Although the column density of Perseus and California cloud is similar to Taurus' and Auriga's, Perseus and California cloud do not show strong absorption in FUV because they are more distant than Taurus and Auriga cloud. We also present the dust scattering simulation based on Monte Carlo Radiative Transfer technique. Through the result of Monte-Carlo dust scattering simulation and comparing the result with FIMS-GALEX unified map we gain deeper understanding related to the spatial dust distribution of TPA region. As a preliminary result of the simulation we present the most probable front face, thickness, albedo, and asymmetry factor in this region, respectively. Through this work we can show a certain inclination of the spatial dust distribution. During this study we have developed the FUV dust scattering simulation code using Monte-Carlo method. We expect that it will be generally used to simulate dust scattering in the Galaxy.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2020년도 봄 학술논문 발표대회
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• pp.210-211
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• 2020

In this study, a questionnaire survey on the occurrence status of fine dust in urban construction sites and the response level was conducted. Based on the results of the survey, it is intended to be used as basic data for establishing a method to reduce fine dust in construction sites.

• 천문학회보
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• 제35권2호
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• pp.71.2-71.2
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• 2010

We present the results of FUV dust scattering simulation, which is based on the Monte-Carlo method. In this simulation, we focus on the multiple scattering in the Ophiuchus complex region because the single scattering case in the region already reported by Lee et al. 2008. We compare the simulation result to the FUV intensity with FIMS and the single scattering result. We also discuss the parameters related to the results of this simulation, such as asymmetry factor, albedo and other different setting-ups.

• 천문학회보
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• 제46권1호
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• pp.57.3-58
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• 2021

We performed three-dimensional Monte Carlo dust scattering radiative transfer simulations for FUV light to obtain dust scattered FUV images and compared them with the observed FUV image obtained by FIMS/SPEAR and GALEX. From this, we find the scattering properties of interstellar dust in our Galaxy and suggest the intensity of extragalactic background light (EBL) at FUV wavelength. The best-fit values of the scattering properties of interstellar dust are albedo = 0.38^-0.04_+0.04, g-factor = 0.55^-0.15_+0.10, and EBL = 138^-23₊₂₁ CU for the allsky which are consistent well with the Milky Way dust model of Draine and direct measurements of Gardner et al., respectively. At the high Galactic latitude of |b|>10°, the observation is well fitted with the model of lower albedo = 0.35^-0.04_+0.06 and g-factor = 0.50^-0.20_+0.15. On the contrary, the scattering properties of interstellar dust show higher albedo = 0.43^-0.02_+0.02 and g-factor = 0.65^-0.15_+0.05 near the Galactic plane of |b|<10°. In the present simulation, recent three-dimensional distribution maps of interstellar dust in our Galaxy, stellar distances in the catalog of GAIA DR2, and FUV fluxes and/or spectral types in the TD-1 and Hipparcos star catalogs were used.

• 천문학논총
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• 제25권4호
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• pp.177-186
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• 2010

We developed an efficient Monte-Carlo algorithm to solve dust-scattering radiative transfer problems for continuum radiation. The method calculates the scattered intensities for various anisotropic factors ($g_i$) all at once, while actual photon packets are tracked following a scattering phase function given by a single anisotropic factor ($g_0$). The algorithm was tested by applying the method to a dust cloud embedding a star at the cloud center and found to provide accurate results within the statistical fluctuation that is intrinsic in Monte-Carlo simulations. It was found that adopting $g_0$ = 0.4 - 0.5 in the algorithm is most efficient. The method would be efficient in estimating the anisotropic factor of the interstellar dust by comparing the observed data with radiative transfer models.

• 한국구조물진단유지관리공학회 논문집
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• 제23권7호
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• pp.40-48
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• 2019

본 연구에서는 건설 현장에서 발생하는 미세먼지의 정확한 측정을 위한 새로운 개념의 알고리즘을 제안한고 검증한다. 기존 측정법의 한계를 보완하기 위하여 초음파 산란 기반 측정법을 제안하였으며, 유한 차분법을 통하여 알고리즘의 활용 및 그 정확성을 검증하고자 하였다. 미세먼지와 같은 다중 산란을 일으키는 현상에 대하여 수학적 모델링을 수행하였고 신호의 감쇠율, 평균 자유 거리, 산란 반경으로 미세먼지의 단위 밀도를 예측할 수 있는 알고리즘을 도출하였다. 2-D 시간 이력해석을 통하여 미세먼지 부피비에 따라 알고리즘을 검증하였으며 신호 해석을 위한 신호처리 기법을 나타내었다. 해석 결과, 알고리즘의 오차는 개수밀도 단위 최소 0.7, 최대 24.9를 보였다. 오차율을 줄이기 위해 미세먼지의 산란 반경을 주파수별로 도출하여야 하는 추후 연구가 필요함을 토의하였다.

• 생물환경조절학회지
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• 제31권2호
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• pp.114-124
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• 2022

새만금은 염분과 미사질 토양으로 인해 지표면이 건조하고 함수율이 낮아 다른 지역에 비해 식생피복이 낮다. 식생 피복도가 낮은 지역에서는 바람에 의한 침식으로 인해 먼지가 비산될 가능성이 높습니다. 새만금 간척지에서 견딜 수 있는 작물을 재배하여 식생 피복도를 높이면 바닥의 유속을 줄여 비산먼지를 줄일 수 있다. 따라서 본 연구의 목적은 새만금 간척지에 겨울철 동계 밭작물을 재배하여 미세먼지 및 비산먼지 발생을 억제하는 효과를 분석하는 것이다. 새만금 간척지에서 보리 0.5ha, 라이밀 0.5ha를 재배하는 동안 농작업 및 생육단계에 따라 미세먼지 농도를 모니터링하였다. PM-10, PM-2.5 및 PM-1.0 농도의 변화는 풍하측, 풍상측, 경작지 내부를 중심으로 모니터링하였다. 모니터링 결과 PM-1.0은 작물 재배에 거의 영향을 미치지 않는 것으로 나타났으며, PM-10과 PM-2.5의 농도는 경운과 수확에 따라 증가하였고 수확에 비해 경운 시 PM-10과 PM-2.5의 농도 증가가 더 높았다. 작물의 생육단계에 따라 비산먼지 억제효과를 보였으며, 유묘기보다 출수기에서 비산먼지 억제효과가 높게 나타났다. 따라서 토지피복효과 이외에 캐노피에 따른 비산먼지 억제효과가 있음을 알 수 있었다. 본 연구를 통해 작물재배에 따른 비산먼지 발생 및 억제 효과에 대해 알 수 있었다.

• 천문학회보
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• 제37권1호
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• pp.74.1-74.1
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• 2012

It is known that the diffuse H${\alpha}$ halos around bright H II regions are more extended than the dust-scattered halos around point sources and the line ratios [S II] ${\lambda}$6716/H${\alpha}$ and [N II] ${\lambda}$6583/H${\alpha}$ observed outside of bright H II regions are generally higher than those in H II regions. These observational facts have been regarded as evidence against the dust-scattering origin of the diffuse H${\alpha}$ emission and the effect of dust-scattering has been neglected in studying the diffuse H${\alpha}$ emission. In this paper, we find, however, that dust-scattered halos of H II regions should be more extended than those of point sources and is in good agreement with the observed H${\alpha}$ profiles around H II regions. We also found that the observed line ratios [S II]/H${\alpha}$, [N II]/H${\alpha}$, and He I ${\lambda}$5876/H${\alpha}$ in the diffuse regions can be well reproduced with the dust-scattered halos around H II regions which are photoionized by late O- and/or early B-type stars in the interstellar medium with the abundances close to those of the warm neutral medium. Therefore, we conclude that the diffuse H${\alpha}$ emission may originate mostly from the dust-scattering.

• 한국입자에어로졸학회지
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• 제14권4호
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• pp.107-119
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• 2018

In this study, we have developed a real-time monitoring device for measuring PM10 and PM2.5 of ambient aerosol particles. The real-time PM monitor (SENTRY Dust Monitor) uses the optical scattering method and has 16 channels in particle size. The laboratory and field tests were carried out to evaluate the developed SENTRY Dust Monitor. Arizona Test Dust particles were used as test particles in the laboratory test and the field test was carried out at the Jongno-gu Observatory in Seoul. The measurements of PM10 and PM2.5 concentrations obtained by SENTTRY Dust Monitor were compared with Grimm Dust Monitor (Model 1.108) and a beta ray gauge. It was shown that the PM10 and PM2.5 concentrations obtained by SENTRY Dust Monitor agree well with that of the reference devices. Based on the results obtained in this study, it could be concluded that the SENTRY Dust Monitor can be used as a PM monitoring device for real-time monitoring of the ambient aerosols.

• 천문학회지
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• 제20권1호
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• pp.1-26
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• 1987

By inverting the brightness integral for the dust-scattered continuum, we have determined how the dust grains are distributed inside the Orion nebula. The scattering characteristics of the Orion dust at a given wavelength is kept constant within the nebula, and the geometry of the nebula is assumed to have a hemispherical shape. The resulting radial distance dependence of the distribution of dust number density, $N_d(r)$, shows that the dust grains are depleted at the central region of the Orion nebula and concentrated in the region $5'{\sim}6'$ away from the Trapezium stars. The scattering characteristics of the Orion dust are of moderately forward throwing nature, and the Orion dust has low values of albedo.