• Title/Summary/Keyword: Cloudy

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Cloudy Area Detection in Satellite Image using K-Means & GHA (K-Means 와 GHA를 이용한 위성영상 구름영역 검출)

  • 서석배;김종우;최해진
    • Proceedings of the IEEK Conference
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    • 2003.11a
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    • pp.405-408
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    • 2003
  • This paper proposes a new algorithm for cloudy area detection using K-Means and GHA (Generalized Hebbian Algorithm). K-Means is one of simple classification algorithm, and GHA is unsupervised neural network for data compression and pattern classification. Proposed algorithm is based on block based image processing that size is l6$\times$l6. Experimental results shows good performance of cloudy area detection except blur cloudy areas.

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Cloudy Area Detection Algorithm By GHA and SOFM

  • Seo, Seok-Bae;Kim, Jong-Woo;Lee, Joo-Hee;Lim, Hyun-Su;Choi, Gi-Hyuk;Choi, Hae-Jin
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.458-460
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    • 2003
  • This paper proposes new algorithms for cloudy area detection by GHA (Generalized Hebbian Algorithm) and SOFM (Self-Organized Feature Map). SOFM and GHA are unsupervised neural networks and are used for pattern classification and shape detection of satellite image. Proposed algorithm is based on block based image processing that size is 16${\times}$16. Results of proposed algorithm shows good performance of cloudy area detection except blur cloudy area.

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Pathological Studies on the Experimentally Induced Rodenticide Poisoning in Ruminant (반추수(反芻獸)의 살서제중독(殺鼠劑中毒)에 관한 병리학적(病理學的) 연구(硏究))

  • Lee, Cha-Soo;Park, Cheong-Kyu;Cho, Yong-Joon;Kwak, Soo-Dong
    • Korean Journal of Veterinary Research
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    • v.22 no.2
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    • pp.221-232
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    • 1982
  • This paper dealt with the pathological and clinical findings on the experimentally induced rodenticide (fluoroacetate, zinc phosphide, thallium sulfate, coumarin) and NaCN poisoning of ruminants (Holstein cattle and/or Korean native goat) for the purpose of the diagnosis in the accidental rodenticide poisoning of cattle. The results observed are summarized as follows: Fluoroacetate poisoning (cattle and goat): in the clinical signs, there were depression, convulsion, dyspnea, groan, grinding of the teeth, vomiting, opisthotonus and post-mortem tympany. In the macroscopical findings, the blood was more or less poor coagulative and dark red, bloody fluid with foam in the trachea, hyperemia and hemorrhage of tracheal mucosa and lung, cloudy swelling and hyperemia of kidney, epicardial hemorrhage(cattle), and hyperemia of abomasum, intestine and brain were observed. In the microscopical findings, there were pulmonary edema and hemorrhage, necrosis of convoluted tubular epithelium and interstitial hemorrhage of kidney, focal coagulative necrosis of myocardium, hemorrhage of pancreas and spleen, dilatation of Virchow-Robin space and hyperemia of brain, and necrosis with desquamation of mucosal epithelia of abomasum and upper small intestine. In the histological lesions of the liver, lobular peripheral hyperemia, centrilobular necrosis and cytoplasmic inclusion bodies of the hetatic cells were observed. The cytoplasmic inclusion body of the hepatic cells was not seen in the affected goat, but hydropic degeneration of the hepatic cells was marked. Zinc phosphide poisoning (cattle and goat): clinically, the affected animals died in recumbent position after ataxia, dyspnea and convulsion. In the macroscopical findings, hyperemia and hemorrhage of lung, cloudy swelling and hyperemia of liver and kidney, hemorrhage of spleen (cattle), and catarrh of abomasum and small intestine were observed. In the microscopical findings, necrosis of the convoluted tubular epithelium and hyperemia of kidney, hemorrhage of spleen, hyperemia of lung, hyperemia or hemorrhage of heart, cloudy. swelling and fatty changes of hepatic cells, dilatation of hepatic central vein, hyperemia of brain, and catarrh of abomasal and small intestinal mucosae were observed. Thallium sulfate poisoning (cattle): in the macroscopical findings dark red color of blood, hyperemia and hemorrhage of lung, bloody fluid with foam in the tracheal mucosa, petechiae of tracheal mucosa, cloudy swelling and hemorrhage of liver, necrotic lesions and hemorrhage of renal cortex and epicardial hemorrhage were observed. In the microscopical findings, severe hemorrhages of the lung, cloudy swelling and necrosis of hepatic cells, hyperemia and hemorrhage of liver, focal coagulative necrosis of mycordium, necrosis of the convoluted tubular epithelium and hyperemia of kidney, hyperemia and hemorrhage of spleen and dilatation of Virchow-Robin apace in brain were observed. Coumarin poisoning (goat): the poisoned animals died in the state of groan and depression. In the macroscopical findings, poor coagulation of blood, hemorrhage of lung, cloudy swelling and severe hemorrhages of liver, cloudy swelling and hemorrhage of kidney, abomasal hemorrhage, catarrh of small intestine, and hyperemia and hemorrhage of the other organs were observed, In the microscopical findings, hyperemia and hemorrhage of lung and kidney, cloudy swelling of the convoluted tubular epithelium of kidney, severe hepatic hyperemia, cloudy swelling and hydropic degeneration of heptatic cell, and hyperemia and hemorrhage of brain and spleen were observed. NaCN poisoning (cattle and goat): clinically, there were convulsion, severe dyspnea, paresis of hind limb, depression and then rigor of four limbs. In the macroscopical findings, bright red color of blood, hyperemia and bright and red tinge of lung cloudy swelling of kidney and liver, and hyperemia of abomasum were observed. In the microscopical findings, cloudy swelling and hydropic degeneration of hepatic cell, hyperemia and edema of lung, necrosis and degeneration of the convoluted tubular epithelium and hemorrhage in kidney, dilatation of Virchow-Robin space of brain and hemorrhage of spleen were observed.

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Performance Comparison of an Urban Canopy Model under Different Meteorological Conditions (기상 조건에 따른 도시 캐노피 모형의 성능 비교)

  • Ryu, Young-Hee;Baik, Jong-Jin;Lee, Sang-Hyun
    • Atmosphere
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    • v.22 no.4
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    • pp.429-436
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    • 2012
  • The performances of the Seoul National University Urban Canopy Model (SNUUCM) under different meteorological conditions (clear, cloudy, and rainy conditions) in summertime are compared using observation dataset obtained at an urban site. The daily-averaged net radiation, sensible heat flux, and storage heat flux are largest in clear days and smallest in rainy days, but the daily-averaged latent heat flux is similar among clear, cloudy, and rainy days. That is, the ratio of latent heat flux to net radiation increases in order of clear, cloudy, and rainy conditions. In general, the performance of the SNUUCM is better in clear days than in cloudy or rainy days. However, the performance in simulating sensible heat flux in clear days is as poor as that in rainy days. For all the meteorological conditions, the performance in simulating latent heat flux is worst among the performances in simulating net radiation, sensible heat flux, and latent heat flux. The normalized mean error for latent heat flux is largest in rainy days in which the relative importance of latent heat flux in the surface energy balance becomes greatest among the three conditions. This study suggests that improvements to the parameterization of processes that are related to latent heat flux are particularly needed.

Research on Visibility in Tourist Attraction of Mt. Sorak Focused on Dae Chung Bong and Kwon Keum Sung (대청봉과 권금성을 중심으로한 설악산 관광명소의 시정(視程)조사)

  • 한국대기환경학회
    • Journal of Korean Society for Atmospheric Environment
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    • v.17 no.3
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    • pp.289-297
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    • 2001
  • From March 1998 to February 1999, we observed visibility and weather change in Dae Chung Bong and Kwon Keum Sung three times a day; at 10 Am, 1 PM and 4 PM. During research period (357 days for Kwon Keum Sung, 351 days for Dae Chung Bong), clear days were 185 days(52%) in Kwon Keum Sung and 149 days (43%) in Dae Chung Bong. Months that had many clear days in a year were December and January in both area. The rate of clear day to cloudy day in Sokcho downtown and Dae Chung Bong was 5 to 5, 4 to 6, respectively. The number of cloudy day in a year in Dae Chung Bong was 34days more than in Sokcho downtown. The visual distance in Kwon Keum Sung was 12.2km on the clear day, and 3.3km on the cloudy day. The yearly average was 7.9km. And we can see 8.9km farther on the clear day. The visual distance in Dae Chung Bong was 13.3km on the clear day, and 3.1km on the cloudy day. The yearly average was 8.1km. The visibility of clear day was 10.2km longer than that of cloudy day. The percentage to observe East Sea clearly was about 70% between December and January in both areas, and showed the highest visibility during research period. We observed Mt. Keumkang from 3 to 6 times in a month except rainy season. The yearly average visibility was 2%. If you go Mt. Serok except April, when there was yellow duet cloud from China, and rainy season (between the last of June and early of September), you can appreciate the most beautiful Mt. Sorak with Mt. Keumkang.

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Photoionization Models for Planetary Nebulae: Comparison of Predictions by NEBULA and CLOUDY

  • Lee, Seong-Jae;Hyung, Siek
    • Journal of the Korean earth science society
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    • v.29 no.5
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    • pp.419-427
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    • 2008
  • The Galactic planetary nebulae emit many strong recombination and forbidden lines. By analyzing such lines, the physical condition of the planetary nebulae has been inferred using the strategically important diagnostic line ratios. In order to fully understand the physical condition of a planetary nebula and to derive its chemical abundances, the photoionization model codes, e.g., CLOUDY and NEBULA, were employed for an analysis of gaseous nebular spectra. For the well-studied, relatively simple planetary nebula NGC 7026, theoretical investigation was done with about the same input parameters in models. The predictions made by both codes seem to be in good accord. However, the predicted physical conditions, such as electron temperature and density, are slightly different. Especially, the electron temperatures are predicted to be higher in CLOUDY, which may cause a problem in chemical abundance determination. Our analysis shows that the main discordance may occur due to the diffuse radiation.

Characteristics of Precipitable Water Vapor and Liquid Water Path Retrieved from a Ground-based Microwave Radiometric Profiler at Haenam NCIO (해남 라디오미터로부터 산출된 가강수량과 구름물량의 분포특성)

  • Won, Hye Young;Kim, Yeon-Hee;Chang, Dong-Eon
    • Atmosphere
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    • v.20 no.1
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    • pp.1-12
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    • 2010
  • Temporal distributions and characteristics of PWV (Precipitable Water Vapor) and LWP (Liquid Water Path) are investigated by using the microwave radiometric profiler at Haenam NCIO from 1 August 2007 to 31 July 2008. Temporal variations of PWV are closely connected with the thermal response of water vapor in atmosphere. The variations of LWP are characterized by the rainfall variation being basically attributable to the heavy rain-bearing clouds. The frequency distributions of PWV and LWP according to the four sky conditions ('clear', 'lightly cloudy', 'cloudy', and 'deeply cloudy') by total cloud amount at Wando Observatory corresponds with a change of slope in cumulative distribution function for PWV and LWP. There results implies that the classification of sky condition can be applied by using the distribution of PWV and LWP from microwave radiometric profiler.

A Study of the Photo-Electric Efficiency of Dye-Sensitized Solar Cells Under Lower Light Intensity

  • Kim, Hee-Je;Kim, Yong-Chul;Hong, Ji-Tae;Kim, Mi-Jeong;Seo, Hyun-Woong;Park, Je-Wook;Choi, Jin-Young
    • Journal of Electrical Engineering and Technology
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    • v.2 no.4
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    • pp.513-517
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    • 2007
  • To elucidate possible challenges for outdoor practical use of dye-sensitized solar cells (DSCs), we compared conventional Si solar cells with DSCs. DSC modules still require a larger area than conventional Si solar modules to attain the same rated output because of lower photoelectron-chemical conversion efficiency. However, in backup systems by using batteries, the measured data shows that DSCs generated 15% more electricity than Si solar cells of the same rated output power in the same interval of cloudy daylight. Moreover, the battery charging time of DSCs is about 1 hour faster than the same rate of Si solar cells under outdoor cloudy daylight. This result also indicates that conversion efficiency obtained by the certified condition less than AM 1.5 condition does not always coincide with the electricity generated outdoors daily, and it is not a crucial measure to evaluate the performance of solar cells.

Nitrate Poisoning Occurred in Holstein Calves (홀스타인 독우(犢牛)에 발생(發生)한 질산염중독(窒酸鹽中毒))

  • Lee, Cha Soo
    • Korean Journal of Veterinary Research
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    • v.18 no.1
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    • pp.9-13
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    • 1978
  • Nitrate poisoning was observed in Holstein calves raising for beef purpose in a dairy-farm of Gyeongbug province. The results observed were summarized as follows: 1. These calves had been fed mainly cornstalk, and a qualitative reaction by "dephenylamine blue test" for nitrate was positive in the serum of the affected calves and in the cornstalk provided. 2. In the clinical signs, the affected calves were suddenly recumbent without premonition and then dyspnea, followed by death. Death also occurred after inappetence, depression, dyspnea, cyanosis of mucous membrane, and terminal anoxic convulsions were observed. 3. In the macroscopical findings, the blood was dark brown (chocolate in color) and more or less poor coagulative. Petechiae of epicardium, severe cloudy swelling of liver, cloudy swelling and hemorrhage of kidney, congestion and hemorrhage of spleen, congestion and edema of lung, and congestion af abomasum and small intestine were observed in these cases. 4. Microscopical changes observed in these cases were peripheral congestion of lobules, centrilobular necrosis and sinusoidal dilatation in liver, hydropic degeneration of hepatic cells, hemorrhage and edema of kidney, necrosis of convoluted-tubular epithelium, and dilatation of Bowman's space and convoluted tubule. There were also congestion and hemorrhage of spleen, hemorrhage and edema of lung, cloudy swelling of myocardium, and congestion and hemorrhage of various organs.

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The prediction of reduction ranges of daylight illuminance in small office for sky and shading conditions (천공 및 차양조건에 따른 소규모 사무실의 주광 조도 감소범위 예측)

  • Jang, Seo Yeon
    • Land and Housing Review
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    • v.10 no.3
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    • pp.33-41
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    • 2019
  • This study examines the distributions of daylight illuminance in a small office space under clear and cloudy sky conditions. Three shading conditions using Venetian blinds were applied for the analysis of daylight illuminance. Computer simulations using the Lightscacpe were conducted for the daylight conditions applied to the office space. Results indicate that the illuminance differences between clear and cloudy sky for south-facing conditions were greater than those for north-facing conditions. The differences in December and June were the greatest and smallest, respectively. For the north-facing conditions, the daylight illuminance at 10:00, 12:00 and 14:00 in June and September under the cloudy sky was higher than those under the clear sky conditions. For all daylight conditions, the biggest amount of illuminance reduction occurred when the shading device conditions were changed from the no blind to the 45 degree blinds. As the distance from window increased, the shading effect that occurred when the shading device conditions were changed from the horizontal blind to the 45 degree blinds increased.