• Ocean and Polar Research
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• 제26권3호
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• pp.439-451
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• 2004

Total solar irradiance (750), total UV irradiunce (TUV) and erythemal UV irradiance (EUV) measured at King Sejong station $(62.22^{\circ}S,\;58.78^{\circ}W)$ in west Antarctica have been used together with total ozone, cloud amount and snow cover to examine the effects of ozone, cloud and snow surface on these surface solar inadiunce over the period of 1998-2003. The data of three solar components for each scan were grouped by cloud amount, n in oktas $(0{\leq}n<3,\;3{\leq}n<4,\;4{\leq}n<5,\;5{\leq}n<6,\;6{\leq}n<7\;and\;7{\leq}n<8)$ and plotted against solar zenith angle (SZA) over the range of $45^{\circ}\;to\;75^{\circ}$. The radiation amplification factor (RAE) is used to quantify ozone effect on EUV. RAF of EUV decreases from 1.51 to 0.94 under clear skies but increases from 0.94 to 1.85 under cloudy skies as SZA increases, and decreases from 1.51 to 1.01 as cloud amount increases. The effects of cloud amount and snow surface on EUV are estimated as a function of SZA and cloud amount after normalization of the data to the reference total ozone of 300 DU. In order to analyse the transmission of solar radiation by cloud, regression analyses have been performed for the maximum values of solar irradiance on clear sky conditions $(0{\leq}n<3)$ and the mean values on cloudy conditions, respectively. The maximum regression values for the clear sky cases were taken to represent minimum aerosol conditions fur the site and thus appropriate for use as a normalization (reference) factor for the other regressions. The overall features for the transmission of the three solar components show a relatively high values around SZAs of $55^{\circ}\;and\;60^{\circ}$ under all sky conditions and cloud amounts $4{\leq}n<5$ and $5{\leq}n<6$. The transmission is, in general, the largest in TUV and the smallest in EUV among the three components of the solar irradiance. If the ground is covered with snow on partly cloudy days $(6{\leq}n<7)$, EUV increases by 20 to 26% compared to snow-free surface around SZA $60^{\circ}-65^{\circ}$, due to multiple reflections and scattering between the surface and the clouds. The relative difference between snow surface and snow-free surface slowly increases from 9% to 20% as total ozone increases from 100 DU to 400 DU under partly cloud conditions $(3{\leq}n<6)$ at SZA $60^{\circ}$. The snow effects on TUV and TSO are relatively high with 32% and 34%, respectively, under clear sky conditions, while the effects changes to 36% and 20% for TUV and TSO, respectively, as cloud amount increases.

• 대한원격탐사학회지
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• 제34권6_1호
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• pp.1025-1032
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• 2018

적설은 강수의 한 형태로 지표면에 쌓인 눈으로 정의되며 빙권의 가장 큰 단일 구성 요소로서 지구 표면과 대기 사이의 열 교환이나 전 지구 또는 지역적인 측면에서 지구의 에너지 수지 균형을 유지하는 중요한 역할을 하는 등 지구 표면 온도를 조절하는데 영향을 미친다. 그러나 적설은 인간의 접근이 어려운 지역에 주로 분포하기 때문에 위성을 활용한 적설 탐지가 활발히 수행되고 있으며 산림 지역의 적설 탐지는 구름과 적설의 구분 다음으로 중요한 과정이다. 따라서 본 연구는 기존 극 궤도 위성에서 산림 지역 적설 탐지에 활용하는 Normalized Difference Snow Index(NDSI) 및 Normalized Difference Vegetation Index(NDVI)를 정지궤도 위성에 적용하였으며, 산림 지역 외 영역은 적설의 분광 특징을 활용한 $R_{1.61{\mu}m}$ anomaly 기법 및 NDSI를 활용하여 적설 탐지를 수행하였다. 본 연구에서 산출한 Snow Cover 자료와 Visible Infrared Imaging Radiometer(VIIRS) Snow Cover 자료를 활용해 간접 검증을 수행한 결과, Probability of Detection(POD)는 99.95%, False Alarm Ratio(FAR)는 16.63 %로 나타났다. Himawari-8 Advanced Himawari Imager(AHI) RGB 영상을 추가로 활용해 정성적 검증 또한 수행하였으며 수행 결과, VIIRS Snow Cover가 미탐지한 영역과 본 연구가 오탐지한 영역이 혼합되어 나타났다.

• 복식
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• 제67권2호
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• pp.88-100
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• 2017

This study is for the textiles of at Sun Am Temple and characteristic of embroidery. Tak Ui was composed of orange body and green upper cover, and had no strings. The body plate was covered with embroidery, with Gauze base, and upper part was appliqued, by cutting dragon pattern, cloud pattern on satin damask. The thread for embroidery was silk floss, silk twisted thread, rapped gold thread, and rapped silk thread. For padding, it was used cotton thread in the part of dragon's scales. It was used satin stitch, outline stitch, split stitch, couching, and counted stitch, etc. as method of embroidery. In particular, it embroidered counted stitch of diamond shape consecutively on the whole of Tak Ui, it does so with counted stitch of same effect of weaving Brocade in the part of cloud. Besides, it is one of the characteristic for couching rapped silk thread. Such lead embroidery is the popular method in the Ming dynasty of China, in the 16~17 century. The design of Tak Ui is dragon, cloud, and wave in the theme. In the center, 'Seong-su-man-nyeon' was placed on the heads of dragon. This is similar to Dragon Robe of Four-petalled medallion patterns, period of Ming dynasty in China. Therefore, it confirmed that Tak Ui was remodeled the embroidered textiles, made for royal robe, originally, with Tak Ui at temple.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 추계학술대회 초록집
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• pp.131-131
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• 2011

태양광 및 태양열 설비의 효율적인 관리를 위해서는 관련 일사정보가 사전정보로 제공되어 시스템 운용을 위한 입력인자로 활용되어야 한다. 특히 전력그리드에 연계되어 설비가 활용된다고 하면, 그 에너지 공급이 불규칙적인 신재생에너지원의 특성으로 인해 에너지 공급량의 예측이 선행되어 기존의 전력공급체계가 이를 지원할 수 있는 모델과 시스템이 구비되어야 한다. 기존의 다양한 연구들이 한정된 국소지점에 대해 다양한 예측기법을 적용하여 평가를 실시하였지만, 장기간의 결과 축적이 이루어지지 못해 그 신뢰성 확보에 어려움을 겪고 있다. 본 연구에서는 현재 한국에너지기술연구원에서 관리되는 일사정보를 활용하여 청명한 날의 표준 일사 데이터베이스를 생성하고, 기상청에서 RSS(Rich Site Summary) 형태로 지원하는 운량정보를 이용하여 3시간 이상의 미래정보를 계속적으로 산출할 수 있는 시스템을 제작하고자 하였다.

• 한국방재학회 논문집
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• 제9권2호
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• pp.45-51
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• 2009

지구기후모델을 이용하여 예측된 (1) 물성치와 (2) 현재 및 미래의 표면 에너지 입력상수의 가변성을 고려한 동결 및 융해깊이를 예측하기 위하여 확률론적 접근법이 도입되었다. 확률론적 접근법을 예시하기 위하여 극지방에서의 융해깊이 예측을 고려해보았다. 특히 확률론적 융해깊이 예측을 위하여 몬테카를로 시뮬레이션과 함께 Stefan 공식이 사용되었다. 시뮬레이션 결과는 물성치의 가변성을 보여주었다. 표면 에너지 입력상수와 온도 데이터는 융해깊이를 예측하는데 상당한 불확실성을 야기시킬 수 있다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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• pp.329-332
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• 2007

Annual vegetation growth patterns are determined by the intrinsic phenological characteristics of each land cover types. So, if typical growth patterns of each land cover types are well-estimated, and a NDVI time-series data of a certain area is compared to those estimated patterns, we can implement more advanced analyses such as a land surface-type classification or a land surface type change detection. In this study, we utilized Terra MODIS NDVI 250m data and compressed full annual NDVI time series data into several indices using the Harmonic Analysis of Time Series(HANTS) algorithm which extracts the most significant frequencies expected to be presented in the original NDVI time-series data. Then, we found these frequencies patterns, described by amplitude and phase data, were significantly different from each other according to vegetation types and these could be used for land cover classification. However, in spite of the capabilities of the HANTS algorithm for detecting and interpolating cloud-contaminated NDVI values, some distorted NDVI pixels of June, July and August, as well as the long rainy season in Korea, are not properly corrected. In particular, in the case of two or three successive NDVI time-series data, which are severely affected by clouds, the HANTS algorithm outputted wrong results.

• 한국측량학회지
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• 제38권5호
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• pp.435-441
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• 2020

Sentinel-2A satellite imagery provides VNIR (Visible Near InfraRed) and SWIR (ShortWave InfraRed) wavelength bands, and it is known to be effective for land cover classification, cloud detection, and environmental monitoring. Greenhouse is one of the middle classification classes for land cover map provided by the Ministry of Environment of the Republic of Korea. Since greenhouse is a class that has a lot of changes due to natural disasters such as storm and flood damage, there is a limit to updating the greenhouse at a rapid cycle in the land cover map. In the present study, we utilized Sentinel-2A satellite images that provide both VNIR and SWIR bands for the detection of greenhouse. To utilize Sentinel-2A satellite images for the detection of greenhouse, we produced high-resolution SWIR bands applying to the fusion technique performed in two stages and carried out the detection of greenhouse using SVM (Support Vector Machine) supervised classification technique. In order to analyze the applicability of SWIR bands to greenhouse detection, comparative evaluation was performed using the detection results applying only VNIR bands. As a results of quantitative and qualitative evaluation, the result of detection by additionally applying SWIR bands was found to be superior to the result of applying only VNIR bands.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2012년도 춘계학술논문집 2부
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• pp.845-847
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• 2012

본 논문에서는 다수의 Landsat 영상을 이용하여 구름지역을 보정한 영상을 제작하였다. 비슷한 시기에 취득된 다수의 영상에서 구름을 제거하고, 구름이 제거된 부분을 다른 영상의 온전한 화소값을 기준으로 복원함으로써 효과적으로 구름지역 보정 영상을 제작할 수 있었다. 제작된 영상은 구름 때문에 식별이 불가능한 지역을 크게 감소시켰으며, 주기적인 위성영상의 취득이 어려운 여건을 개선하는 한편, 대규모 지역의 변화탐지 및 영상분류 등 다양한 분야에 활용될 것이다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 1998년도 Proceedings of International Symposium on Remote Sensing
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• pp.242-245
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• 1998

Interferometric Monitor for Greenhouse Gases (IMG) is a sensor to monitor the earth's radiation balance, the temperature profile of the atmosphere, the temperature of the earth's surface, and physical properties of clouds, and was loaded on ADEOS satellite. In this paper, we estimated IMG level 2 data by comparing with a Clobal Telecommunications System data (GTS). The IMG level 2 data over sea without cloud cover gave good agreement with the value that had been obtained by buoy and sonde.

• KIEAE Journal
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• 제14권2호
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• pp.3-10
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• 2014

Impact by estimation error of hourly horizontal global solar radiation in a weather file on building energy performance was investigated in this study. There are a number of weather parameters in a given weather file, such as dry-bulb, wet-bulb, dew-point temperatures; wind speed and direction; station pressure; and solar radiation. Most of them except for solar radiation can be easily obtained from weather stations located on the sites worldwide. However, most weather stations, also including the ones in South Korea, do not measure solar radiation because the measuring equipment for solar radiation is expensive and difficult to maintain. For this reason, many researchers have studied solar radiation estimation models and suggested to apply them to predict solar radiation for different weather stations in South Korea, where the solar radiation is not measured. However, only a few studies have been conducted to identify the impact caused by estimation errors of various solar radiation models on building energy performance analysis. Therefore, four different weather files using different horizontal global solar radiation data, one using measured global solar radiation, and the other three using estimated global solar radiation models, which are Cloud-cover Radiation Model (CRM), Zhang and Huang Model (ZHM), and Meteorological Radiation Model (MRM) were packed into TRY formatted weather files in this study. These were then used for office building energy simulations to compare their energy consumptions, and the results showed that there were differences in the energy consumptions due to these four different solar radiation data. Additionally, it was found that using hourly solar radiation from the estimation models, which had a similar hourly tendency with the hourly measured solar radiation, was the most important key for precise building energy simulation analysis rather than using the solar models that had the best of the monthly or yearly statistical indices.