• Journal of the Korean Solar Energy Society
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• v.32 no.2
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• pp.28-34
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• 2012

It is necessary to estimate the regression coefficients in order to predict the daily global radiation on a horizontal surface. Therefore many different equations have proposed to evaluate them for certain areas. In this work a new correlation has been made to predict the solar radiation for 16 different areas over Korea by estimating the regression coefficients taking into account cloud hours of bright sunshine. Particularly, the multiple linear regression model proposed shows reliable results for estimating the global radiation on a horizontal surface with monthly average deviation of-0.26 to +0.53% and each station annual average deviation of -1.61 to +1.7% from measured values.

• Proceedings of the KSRS Conference
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• 2008.10a
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• pp.378-381
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• 2008

The regulating and relaxing targets in the Land Use Regulation and Total Maximum Daily Loads are influenced by Land cover information. For the providing more accurate land information, this study attempted to generate an impervious surface map using KOMPSAT-2 image which a Korea manufactured high resolution satellite image. The classification progress of this study carried out by tasseled-cap spectral enhancement through each class extraction technique neither existing classification method. KOMPSAT-2 image of this study is enhanced by Soil Brightness Index(SBI), Green vegetation Index(GVI), None-Such wetness Index(NWI). Then ranges of extracted each index in enhanced image are determined. And then, Confidence Interval of classes was determined through the calculating Non-exceedance Probability. Spectral distributions of each class are changed according to changing of Control coefficient(${\alpha}$) at the calculated Non-exceedance Probability. Previously, Land cover classification map was generated based on established ranges of classes, and then, pervious and impervious surface was reclassified. Finally, impervious ratio of reclassified impervious surface map was calculated with blocks in the study area.

• Journal of Korean Academic Society of Home Health Care Nursing
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• v.24 no.1
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• pp.52-60
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• 2017

Purpose: This study sought to identify the relationship between knowledge and compliance with cough etiquette among elders in the community. Methods: Participants were 186 olders. Data were collected December 2016 and analyzed using descriptive statistics, t-test, ANOVA, Pearson correlation coefficients, and stepwise multiple regression. Results: Mean scores for knowledge and compliance relating to cough etiquette were above average. Several factors were related to significant differences in level of knowledge: education level, use of items to cover a cough, Carrying a handkerchief or tissue, daily frequency of hand washing, awareness of cough etiquette, and prior education on cough etiquette. Compliance differed according to use of items to cover a cough, awareness of cough etiquette, and prior education on cough etiquette. Significant correlations were found between knowledge and compliance with cough etiquette. Awareness of cough etiquette and knowledge of cough etiquette were predictors of cough etiquette compliance. Conclusion: These findings indicate that publicity and education taking into account the characteristics of the elderly are required to improve compliance with cough etiquette among olders. The results of the study can be utilized in health promotional programs for this population.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.10 no.3
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• pp.60-70
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• 2007

Green space infrastructures for three cities, Gwacheon, Uiwang, and Hanam, were analyzed in terms of the area of urban parks per capita, the percentage of green space area, the area of green space per capita, and the percentage of vegetation cover in residential area, etc., which are commonly used as criteria for urban green space planning. The differences in green space infrastructure among these three cities were compared to the satisfaction level of residents for their green space. The area of parks per capita corresponded to the satisfaction level when Seoul Great Park in Gwacheon and Misa Park in Hanam were not included. Although these two huge parks accounted more than 90% of the area of urban parks in Gwacheon and Hanam, they serve more people from outside the cities and not likely visited by residents due to lacking of daily accessibility. The percentage of vegetation cover in residential area were considered to affect the satisfaction of residents for green space, whereas the total area of green space or the percentage of green space area in the cities was not related to the satisfaction level. It suggests that the distributions and accessibilities of green space and park service are more important for satisfaction than total green space area indicating urban sustainability.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.153-153
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• 2019

Evapotranspiration (ET) is an important component of hydrological processes. Accurate estimates of ET variation are of vital importance for natural hazard adaptation and water resource management. This study first developed a soil water index (SWI)-based Priestley-Taylor algorithm (SWI-PT) based on the enhanced vegetation index (EVI), SWI, net radiation, and temperature. The algorithm was then compared with a modified satellite-based Priestley-Taylor ET model (MS-PT). After examining the performance of the two models at 10 flux tower sites in different land cover types over East Asia and Australia, the daily estimates from the SWI-PT model were closer to observations than those of the MS-PT model in each land cover type. The average correlation coefficient of the SWI-PT model was 0.81, compared with 0.66 in the original MS-PT model. The average value of the root mean square error decreased from $36.46W/m^2$ to $23.37W/m^2$ in the SWI-PT model, which used different variables of soil moisture and vegetation indices to capture soil evaporation and vegetative transpiration, respectively. By using the EVI and SWI, uncertainties involved in optimizing vegetation and water constraints were reduced. The estimated ET from the MS-PT model was most sensitive (to the normalized difference vegetation index (NDVI) in forests) to net radiation ($R_n$) in grassland and cropland. The estimated ET from the SWI-PT model was most sensitive to $R_n$, followed by SWI, air temperature ($T_a$), and the EVI in each land cover type. Overall, the results showed that the MS-PT model estimates of ET in forest and cropland were weak. By replacing the fraction of soil moisture ($f_{sm}$) with the SWI and the NDVI with the EVI, the newly developed SWI-PT model captured soil evaporation and vegetation transpiration more accurately than the MS-PT model.

• Journal of the Korean Association of Geographic Information Studies
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• v.6 no.1
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• pp.107-118
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• 2003

The purpose of this study is to assess the hydrological impact on a watershed from long-term land cover changes. Gyeongan-cheon watershed($558.2km^2$) was selected and WMS(watershed modeling system) HEC-1 model was adopted as an evaluation tool. To identify land cover changes, five Landsat images(1980/2/15, 1986/4/15, 1990/4/26, 1996/4/26, 2000/5/17) were selected and analyzed using maximum likelihood method. As a result, urban areas have increased by 5.6% and forest areas have decreased by 6.1% between 1980 and 2000. SCS curve number increased by 9.8. To determine model parameters and evaluate HEC-1 model, five storm events(1998/5/2, 1998/8/23, 1998/9/30, 1999/5/3, 2000/7/29) were used. The simulated stream flow agreed well with the observed one with relative errors ranging from 9% to 36%. For 254 mm daily rainfall of 30 years frequency, due to the increase of urban areas peak flow increased by $455m^3/sec$ and the time of peak flow reduced about four hours for 20 years land cover changes.

• Korean Journal of Agricultural and Forest Meteorology
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• v.3 no.4
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• pp.215-219
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• 2001

Land surface parameterization schemes for atmospheric models as well as decision support tools for ecosystem management require a frequent updating of land cover classification data for regional to global scales. Rice paddies have not been treated independently from other agricultural land classes in many classification systems, despite their atmospheric and ecological significance. A simple but improved method over conventional land cover classification schemes for rice paddy is suggested. Normalized difference vegetation index (NDVI) was calculated for the land area of South Korea at a 1km by 1 km resolution from the visible and the near-infrared channel reflectances of NOAA-AVHRR (Advanced Very High Resolution Radiometer). Monthly composite images of daily maximum NDVI were prepared for May and August, and used to classify 4 major land cover classes : urban, farmland, forests and water body. Among the pixels classified as "forests" in August, those classified as "water body" in May were assigned a "rice paddy" class. The distribution pattern of "rice paddy" pixels was very similar to the reported rice acreage of 1,455 Myons, which is the smallest administrative land unit in Korea. The correlation coefficient between the estimated and the reported acreage of Myons was 0.7, while 0.5 was calculated from the USGS classification.calculated from the USGS classification.

• Journal of Institute of Convergence Technology
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• v.4 no.2
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• pp.27-33
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• 2014

To well design the solar energy system using solar energy, the correlation to calculate solar irradiation is basically needed. So, this study was performed to reveal the relationships between the solar irradiation and four meteorological observation data(dry bulb temperature, relative humidity, sunshine duration, and cloud cover) which are different from previous other researches. And then, we finally proposed the first order non-linear correlation from the measured solar irradiation using four meteorological observation data with MINITAB. To show the deviation of the solar irradiation between measured and calculated, this study compared using the daily total solar irradiance and the maximum peak value. From those results, the calculation error was estimated about maximum 25.4% for the daily total solar irradiance. The error of the solar irradiation between measured and calculated was made from the curve fitting error. So, solar irradiation prediction correlation with higher accuracy can be obtained using 2nd or higher order terms with four meteorological observation data.

• Journal of Institute of Convergence Technology
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• v.9 no.1
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• pp.31-36
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• 2019

After 30 years of KKP model analysis and extended 30 years of accuracy analysis, the unique correlation and various problems between measured horizontal surface insolation and measured weather data are found in this paper. The KKP model's 10yrs daily total horizontal surface insolation forecasting was averaged about 97.7% on average, and the forecasting accuracy at peak times per day was about 92.1%, which is highly applicable regardless of location and weather conditions nationwide. The daily total solar radiation forecasting accuracy of the modified KKP cloud model was 98.9%, similar to the KKP model, and 93.0% of the forecasting accuracy at the peak time per day. And the results of evaluating the accuracy of calculation for 30 years of KKP model were cloud model 107.6% and cloud model 95.1%. During the accuracy analysis evaluation, this study found that inaccuracies in measurement data of cloud cover should be clearly assessed by the Meteorological Administration.

• Atmosphere
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• v.16 no.3
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• pp.187-201
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• 2006

During summer (JJA) of 2004, a record-high temperature in Korea appeared at Miryang ($38.5^{\circ}C$ on July 30). Moreover, Miryang showed the most frequent occurrence (25 days in JJA) of the daily highest temperature among observational sites in Korea. Based on meteorological analysis, it is found that this phenomenon is caused by neither the global warming effect nor the urban climate effect. It is caused by the mesoscale and synoptic and/or global scale atmospheric circulations, as evidenced by several factors described below. Firstly, the hottest areas have normally occurred not at a point but over an area, particularly along an axis connecting Sancheong and Daegu. But in 2004, this axis has moved southward and locates over Namhae-Miryang due to northerlies that were induced by the heating effect related to the low snow-cover on the Tibet Plateau. Secondly, although the maximum temperature was the highest among observational sites in Korea, the daily mean temperature and the number of nights with air temperature over $25^{\circ}C$ were not the highest at Miryang. Thirdly, the downdraft induced by the second circulation of typhoon and abnormal development of the North-Pacific High were found to have exerted an important role.