• Korean Journal of Remote Sensing
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• v.14 no.1
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• pp.53-68
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• 1998

Observation of hydrometeors' behavior in the atmosphere is important to understand weather and climate. By conventional observations, we can get the distribution of water vapor at limited number of points on the earth. In this study, the precipitable water has been estimated from the split window channel data on GMS-5 based upon the technique developed by Chesters et al.(1983). To retrieve the precipitable water, water vapor absorption parameter depending on filter function of sensor has been derived using the regression analysis between the split window channel data and the radiosonde data observed at Osan, Pohang, Kwangiu and Cheju staions for 4 months. The air temperature of 700 hPa from the Global Spectral Model of Korea Meteorological Administration (GSM/KMA) has been used as mean air temperature for single layer radiation model. The retrieved precipitable water for the period from August 1996 through December 1996 are compared to radiosonde data. It is shown that the root mean square differences between radiosonde observations and the GMS-5 retrievals range from 0.65 g/$cm^2$ to 1.09 g/$cm^2$ with correlation coefficient of 0.46 on hourly basis. The monthly distribution of precipitable water from GMS-5 shows almost good representation in large scale. Precipitable water is produced 4 times a day at Korea Meteorological Administration in the form of grid point data with 0.5 degree lat./lon. resolution. The data can be used in the objective analysis for numerical weather prediction and to increase the accuracy of humidity analysis especially under clear sky condition. And also, the data is a useful complement to existing data set for climatological research. But it is necessary to get higher correlation between radiosonde observations and the GMS-5 retrievals for operational applications.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.1
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• pp.23-31
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• 2013

Microwave remote sensing can help monitor the land surface water cycle and crop growth. This type of remote sensing has great potential over conventional remote sensing using the visible and infrared regions due to its all-weather day-and-night imaging capabilities. In this paper, a ground-based multi-frequency (L-, C-, and X-band) polarimetric scatterometer system capable of making observations every 10 min was developed. This system was used to monitor the wheat over an entire growth cycle. The polarimetric scatterometer components were installed inside an air-conditioned shelter to maintain constant temperature and humidity during the data acquisition period. Backscattering coefficients for the crop growing season were compared with biophysical measurements. Backscattering coefficients for all frequencies and polarizations increased until dat of year 137 and then decreased along with fresh weight, dry weight, plant height, and vegetation water content (VWC). The range of backscatter for X-band was lower than for L- and C-band. We examined the relationship between the backscattering coefficients of each band (frequency/polarization) and the various wheat growth parameters. The correlation between the different vegetation parameters and backscatter decreased with increasing frequency. L-band HH-polarization (L-HH) is best suited for the monitoring of fresh weight (r=0.98), dry weight (r=0.96), VWC (r=0.98), and plant height (r=0.96). The correlation coefficients were highest for L-band observations and lowest for X-band. Also, HH-polarization had the highest correlations among the polarization channels (HH, VV and HV). Based on the correlation analysis between backscattering coefficients in each band and wheat growth parameters, we developed prediction equations using the L-HH based on the observed relationships between L-HH and fresh weight, dry weight, VWC and plant height. The results of these analyses will be useful in determining the optimum microwave frequency and polarizations necessary for estimating vegetation parameters in the wheat.

• The Journal of Dong Guk Oriental Medicine
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• v.8 no.2
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• pp.1-24
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• 2000

The comparison of climate's character of Yunqi(運氣) with the data of meterological observation were made in the research of climate. 1. The comparison of the average velocity of wind, temperature, rainfall, humidity of Seoul, by late 1954 to 1983, with Yunqi(運氣) was made. Fire-Chi(火氣) and moisture-qi(濕氣) were matched with the attribute of Taiyun(大運). Cold-qi(寒氣) was had some relationship. Dry-qi(燥 氣) and Wind-qi(風氣) were not matched. About the relationship of Spirit-of-official-sky(司天之氣) with climate, when the Moisture-soil(濕土) was added, they were matched and when the King-fire(君火) was added, they have some relationship. But Wind-tree(風木), Dry-metal(燥金), Buble-fire(相火), Cold-water(寒水) was added they were not matched. 2. According to the observation data of rainfall by late 180 years of Seoul; about Taiyun(大運), when the Water-Yun(水運) was greatly exceeded and Fire-Yun(火運) was shorted, in the case of Official-sky(司天), when Wind-Tree(風木) was added, the frequency was highly. So when the Soil-Yun(土運) was greatly exceeded and when Official-sky(司天)was added to the Moisture-soil(濕土), the rainfall was not matched. 3. The relationship of the frequency of the abnormal climate occurrences between Yunqi-promotion-weak(運氣盛衰)and Yunqi-Harmony(運氣同化) and Yunqi-soft-attacking(運氣順逆) in the weather of Korean Peninsula was compared by 1564 to 1863. They were not matched except the case of Yunqi-Harmony(運氣同化). 4. There were some cases which were not matched exactly between the climate predicted by the theory and real climate in 1984, the year of Kap-ga(甲子年). But many correspondence between the observation by the office of meteorology and the prediction by the analysis from Yun-qi-sang-hab(運氣相合) theory. 5. Because meterological phenomena of real world and analysis from the hypothesis of Yunqi(運氣) have no relationship with each other, some of Doctor denied Yunqi(運氣) in the way of matching mechanically. But the thought of Doctor who denied Fortune-spirit(運氣) made promotion for the theory of divination by bringing deeper insight. And it was not only the negative side. 6. In the point of geographical difference, the climate of China, the origination Yunqi theory, is different from the Korea's. Thus some observation errors should be considered. From the basis of this thesis, I hope that the deeper advance would be made into the Korean Yunqi theory.