• Spatial Information Research
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• v.13 no.1 s.32
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• pp.79-90
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• 2005

The purpose of this study is to estimate quantitatively soil loss and sediment yield in alpine farmland. For this purpose, Naerinchon watershed in Gangwon province was selected as our study area and total annual soil loss and sediment yield was estimated respectively by the Revised Universal Soil Loss Equation (RUSLE) model and the Sediment Delivery Distributed (SEDD) model. The results of this study clearly show that dry field areas have significant impact on the total soil erosion and sediment yield compared with other land use. Dry field areas represent only $2.6\%$ of the total area of the watershed but soil loss and sediment yield account for $10.9\%$ and $33.12\%$ of the total amount respectively Especially as with alpine farmland, this result is more clearly shown. These areas account for $1.8\%$ of the entire watershed but contribute to $7.7\%$ and $15\%$ of the total soil loss and sediment yield respectively. From the above results, we can know that alpine farmland is important source of soil loss and sediment yield and it is need to prevent and control. soil erosion from alpine filmland urgently.

• Journal of Soil and Groundwater Environment
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• v.17 no.6
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• pp.119-128
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• 2012

The applicability and accuracy of Revised Universal Soil Loss Equation (RUSLE) model on the estimation of soil loss at impacted area of shooting range was tested to further the understanding of soil erosion at shooting ranges by using RUSLE. At a shooting range located in northern Kyunggi, the amount of soil loss was estimated by RUSLE model and compared with that estimated by Global Positioning System-Total Station survey. As results, the annual soil loss at a study site (202 m long by 79 m wide) was estimated to be 2,915 ton/ha/year by RUSLE and 3,058 ton/ha/year by GPS-TS survey, respectively. The error between two different estimations was less than 5%, however, information on site conditions should be collected more to adjust model coefficients accurately. At the study shooting range, sediments generated by rainfall was transported from the top to near the bottom of the sloping face through sheet erosion as well as rill erosion, forming a gully along the direction of the storm water flow. Coarser fractions of the sediments were redeposited in the limited area along the channel. Distribution characteristics of explosive compounds in soil before and after summer monsoon rainfall in the study area were compared with the erosion patterns. Soil sampling and analyses results showed that the dispersion of explosive compounds in surface soil was consistent with the characteristics of soil erosion and redeposition pattern of sediment movements after rainfalls.

• Journal of Environmental Impact Assessment
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• v.17 no.4
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• pp.243-253
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• 2008

The purpose of this study was to simulate the reduction effect of soil loss in the Yongdam reservoir watershed using SWAT model. To evaluate accuracy for flow and sediment yield of SWAT model, calibration was performed for the period from Jan. 2002 to Dec. 2003, and the verification for Jan. 2005 to Dec. 2005. The calibration and the verification were carried out using data observed at the Cheoncheon gaging station. The $R^2$ and EI values in terms of a flow were 0.8 and 0.78 respectively for calibration, whereas they for verification were 0.88 and 0.86 respectively. In terms of a sediment yield, they were 0.7 and 0.48 respectively for calibration, whereas for verification were 0.64 and 0.54 respectively. As a results from model simulation, annual mean soil loss rates in terms of forest, paddy and upland were 0.02 ton/ha/yr, 0.15 ton/ha/yr and 7.58 ton/ha/yr, respectively. The results show that the land use type of a upland has more significant impact on a total soil loss as well as a sediment yield than other types of land use. The sediment delivery ratio was determined to be about 0.35. In this study 2 land cover change scenarios for upland area were considered. These scenarios were used an input to SWAT model in order to evaluate their impact on soil loss and sediment delivery. The results show that a reduction of the upland area would reduce the soil loss and sediment yield.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.3
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• pp.211-215
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• 1998

Soil loss and runoff were investigated in a small watershed located in Sangeo-ri, Yeoju-eup, Yeoju-gun, Kyonggi-do. The watershed with the area of 35 ha consists of forest, grassland, uplands and mulberry. V-notch type water tank. flow-meter, automatic water sampler and rain gauge were installed at the main outlet stream. Out of $1.037.9Mg\;35ha^{-1}$ of total annual rainfall. 17.9% was lost via run-off. The total amount of soil eroded was $152.2Mg\;35ha^{-1}$, of which $78.6Mg\;35ha^{-1}$ was suspended load and $73.6Mg\;35ha^{-1}$ ha was sediment load. The soil losses under different land uses were $16.02Mg\;ha^{-1}$ for upland annual Crops. $2.69Mg\;ha^{-1}$ for mulberry field, $0.58Mg\;ha^{-1}$ for grassland and $0.55Mg\;ha^{-1}$ for forest. The predicted soil loss by Universal Soil Loss Equation was approximately 20% underestimated in forest, grassland and uplands, and 32% underestimated in mulberry field.

• Journal of Korea Water Resources Association
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• v.32 no.4
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• pp.457-467
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• 1999

No complete methods for estimating soil loss, included by rain storms, from a small watershed are available yet, and the best recommended method is to use measured data from the watershed. When no measured data is available from the watershed, empirical models for estimating the soil loss, such as the Universal Soil Loss Equation(USLE), is well recommended in practice. For using this equation, it is necessary to estimated the rainfall erosivity, commonly expressed as R, of the watershed. In this study, first we collected data of the probable rainfalls with the return periods of 2, 5, 10, 20, 30, 50, 80, 100, 200, and 500-yr and with the duration hours of 0.5, 1, 2, 3, 6, 12, and 24-hr. Using this data, we calculated the design values for R for the return period of 24-hr at each major rainfall-measuring station nationwide. Then we constructed the iso-erodent map of Korea for each return period of the 24-hr design storm. This study shows that the 24-hr duration iso-erodent map of the 5-yr return period is very similar to the annual average iso-erodent map of Korea. This study also shows that the 24-hr duration R-values of a certain return period can be estimated by multiplying certain parameters, obtained from this study, to the 24-hr duration R-values for the 5-yr return period or the annual average R-values. Finally, the R-values of the design storm with the 24-hr return period obtained from this study can be used for designing the settling basins at small watersheds.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.15 no.5
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• pp.405-412
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• 2022

This paper studies the method of estimating power loss and classifying the factors for improving the power generation efficiency through O&M. It is installed under various climatic conditions worldwide, operational and maintenance technologies suitable for the characteristics of the installation location are required. Existing studies related to solar power generation efficiency have been actively quantifying the impact on short-term losses by environmental factors such as high temperature, dust accumulation, precipitation, humidity, and wind speed, but analysis of the overall impact from a long-term operation perspective is limited. In this study, the potential for efficiency improvement was analyzed by re-establishing a loss classification system according to the power flow of solar power to derive a comprehensive efficiency model for long-term operation and estimating power loss through a case study for each region where climate conditions are classified. As a result of the analysis, the average annual potential for improving soiling loss was 26.9%, Death Valley 7.2%, and Seoul 3.8%. Aging losses was 6.6% in the 20th year as a cumulative. The average annual potential due to temperature loss was 2.9 % for Doha, 1.9% for Death Valley, and 0.2% for Seoul.

• Journal of Internet of Things and Convergence
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• v.7 no.3
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• pp.9-14
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• 2021

This paper discovers the energy loss factors through the insulation diagnosis of houses or buildings, and proposes directions for energy efficiency improvement. The energy efficiency factor of a building consists of insulation diagnosis, thermal bridge diagnosis, window diagnosis, airtight diagnosis, and equipment diagnosis. Among the residents and facilities in the energy welfare blind spot, an energy efficiency diagnosis was conducted for one senior citizen building located in Naju-si, Jeollanam-do, and energy efficiency diagnosis was conducted after insulation was installed. Energy measurement, diagnosis and analysis were performed using the IoT-based integrated wired/wireless energy diagnosis platform, Energy Finder. As a result of comparison, an overall energy saving rate of 16.38% was achieved. Annual heating energy consumption per unit area decreased from 333.51kWh before construction to 277.35kWh after construction, and annual cooling energy consumption per unit area decreased from 5.51kWh before construction to 5.22kWh after construction. The annual primary energy consumption per unit area decreased from 464.52kWh before construction to 403.69kWh after construction, and the annual energy cost was reduced from 3,063,307.14 won before construction to 2,641,072.49 won after construction. The additional improvement work is needed on the standards affecting energy efficiency other than insulation.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.4
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• pp.484-491
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• 2012

The hydrological components of a sandy loam soil of nearly level in Chuncheon over 30 years were computed using the E-DiGOR model. Daily simulations were carried out for each year during the period of 1980 to 2009 using standard climate data. Reference evapotranspiration and potential soil evaporation based on Penman-Montheith model were higher during May to August because of the higher atmospheric evaporative demand. Actual soil evaporation was mainly found to be a function of the amount and timing of rainfall, and presumably soil wetness in addition to atmospheric demand. Drainage was affected by rainfall and increased with a higher amount of precipitation and soil water content. Excess drainage occurred throughout rainy months (from July to September), with a peak in July. Therefore, leaching may be a serious problem in the soils all through these months. The 30-year average annual reference evapotranspiration and potential soil evaporation were 951.5 mm and 714.2 mm, respectively. The actual evaporation from bare soil varied between 396.9-528.4 mm and showed comparatively lesser inter-annual variations than drainage. Annual drainage rates below 120 cm soil depth ranged from 477.8 to 1565.9 mm. The long-term mean annual drainage-loss was approximately two times higher than actual soil evaporation.

• Journal of Hydrogen and New Energy
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• v.24 no.6
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• pp.558-565
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• 2013

This paper presents how to determine AEP(Annual Energy Production) by a small wind turbine in DuckjeokDo island. Evaluation of AEP is introduced to make a self-contained island including renewable energy sources of wind, solar, and tidal energy. To determine the AEP in DuckjeokDo island, a local wind data is analyzed using the annual wind data from Korea Institute of Energy Research firstly. After the wind data is separated in 12-direction, a mean wind speed at each direction is determined. And then, a small wind turbine power curve is selected by introducing the capacity of a small wind turbine and the energy production of the wind turbine according to each wind direction. Finally, total annual wind energy production for each small wind turbine can be evaluated using the local wind density and local energy production considering a mechanical energy loss. Throughout the analytic study, it is found that the AEP of DuckjeokDo island is about 2.02MWh/y and 3.47MWh/y per a 1kW small wind turbine installed at the altitude of 10 m and 21m, respectively.

• Journal of Korea Water Resources Association
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• v.51 no.9
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• pp.783-793
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• 2018

The purpose of this study to present updated regional annual mean rainfall erosivity data in the Republic of Korea. In 2012, Ministry of Environment in Korea published the notice about investigation and survey procedure for the amount of topsoil erosion and adopted USLE (Universal Soil Loss Equation) model to predict the amount of national-scale soil erosion in Korea. In the notice, regional rainfall erosivity values for 158 sites, which is essential to apply the USLE, were included, however, these values came from the data made before 1997 and need to be updated. This study collected, classified and combined annual mean rainfall erosivity data from the literature review to analyze the data. We presented that new iso-erodent map, interpolated by IDW (Inverse Distance Weighted) method and extracted updated regional annual mean rainfall erosivity data at 167 regions for 1961~2015. These values will be used as updated rainfall erosivity data to predict the amount of topsoil erosion in Korea.