• Geomechanics and Engineering
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• v.28 no.6
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• pp.613-624
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• 2022

A study of the evolution of overburden fractures under the solid-fluid coupling state was conducted based on the geological and mining characteristics of the coal seam depth, weak strata cementation, and high-intensity mining in the mining areas of West China. These mining characteristics are key to achieving water conservation during mining or establishing groundwater reservoirs in coal mines. Based on the engineering background of the Daliuta Coal Mine, a non-hydrophilic simulation material suitable for simulating the weakly cemented rock masses in this area was developed, and a physical simulation test was carried out using a water-sand gushing test system. The study explored the spatial distribution and dynamic evolution of the fractured zone in the mining overburden under the coupling of stress and seepage. The experimental results show that the mining overburden can be vertically divided into the overall migration zone, the fracture extension zone and the collapse zone; additionally, in the horizontal direction, the mining overburden can be divided into the primary fracture zone, periodic fracture zone, and stop-fracture zone. The scope of groundwater flow in the overburden gradually expands with the mining of coal seams. When a stable water inrush channel is formed, other areas no longer generate new channels, and the unstable water inrush channels gradually close. Finally, the primary fracture area becomes the main water inrush channel for coal mines. The numerical simulation results indicate that the overlying rock breaking above the middle of the mined-out area allows the formation of the water-conducting channel. The water body will flow into the fracture extension zone with the shortest path, resulting in the occurrence of water bursting accidents in the mining face. The experimental research results provide a theoretical basis for the implementation of water conservation mining or the establishment of groundwater reservoirs in western mining areas, and this theoretical basis has considerable application and promotion value.

• Korean Journal of Agricultural Science
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• v.44 no.4
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• pp.636-641
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• 2017

Water is an essential resource for human survival. According to the OECD Environmental Outlook to 2050, rapid industrialization and a global population increase by approximately two billion will likely increase global water use by 55% in 2050. However, water depletion has been getting worse than before and has been happening more quickly, as Earth's water resources are limited. The present study proposes water management measures by using the virtual water theory which enables water consumption measurement and the confirmation and recognition of water scarcity problems, and will support the development of counter-measures. As a method for estimating the value of agricultural water, virtual water theory was used to calculate the amount of agricultural water input for domestic rice and to apply prices of agricultural water in the United States and China to Korean water prices. When the Chinese price was applied to Korean water prices, the value of agricultural water represented 0.3% of the Korean rice producer's price. When the US price was applied to Korean water prices, the value of agricultural water represented 1.6% of the domestic rice producer's price. The study exposes the percentage of the value of agricultural water in agricultural product prices, as well as how this scare resource may affect future prices. In the future, if there are water charges to effectively manage agricultural water, this study, which uses the virtual water theory, can be used as a preliminary research.

• Agribusiness and Information Management
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• v.9 no.1
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• pp.7-17
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• 2017

Agricultural water management has gained enormous attention in the developing world to alleviate poverty, reduce hunger and conserve ecosystems in small-scale production systems of resource-poor farmers. The story of food security in the $21^{st}$ century in India is likely t o be closely linked to the story of water security. Today, the water resource is under severe threat. The past experiences in India in general and in Andhra Pradesh in particular, indicated inappropriate management of irrigation has led to severe problems like excessive water depletion, reduction in water quality, water logging, salinization, marked reduction in the annual discharge of some of the rivers, lowering of ground water tables due to pumping at unsustainable rates, intrusion of salt water in some coastal areas etc. Considering the importance of irrigation water resource efficiency, Krishna Western Delta (KWD) of Andhra Pradesh was purposively selected for this in depth study, as the farming community in this area are severely affected due to severe soil salinity and water logging problems and hence, adoption of different water saving crop production technologies deserve special mention. It is quite disappointing that, canals, tube wells and filter points and other wells could not contribute much to the irrigated area in KWD. Due to less contribution from these sources, the net area irrigated also showed declining growth at a rate of -6.15 per cent. Regarding paddy production, both SRI and semi-dry cultivation technologies involves less irrigation cost (Rs. 2475.21/ha and Rs. 3248.15/ha respectively) when compared to transplanted technology (Rs. 4321.58/ha). The share of irrigation cost in Total Operational Cost (TOC) was highest for transplanted technology of paddy (11.06%) followed by semi-dry technology (10.85%) and SRI technology (6.21%). The increased yield and declined cost of cultivation of paddy in SRI and semi-dry production technologies respectively were mainly responsible for the low cost of production of paddy in SRI (Rs. 495.22/qtl) and semi-dry (Rs. 532.81/qtl) technologies over transplanted technology (Rs. 574.93/qtl). This clearly indicates that, by less water usage, paddy returns can be boosted by adopting SRI and semi-dry production technologies. Both the system-level and field-level interventions should be addressed to solve the issues/problems of water management. The enabling environment, institutional roles and functions and management instruments are posing favourable picture for executing the water management interventions in the State of Andhra Pradesh in general and in KWD in particular. This facilitates the farming community to harvest good crop per unit of water resource used in the production programme. To achieve better results, the Farmers' Organizations, Water Users Associations, Department of Irrigation etc., will have to aim at improving productivity per unit of water drop used and this must be supported through system-wide enhancement of water delivery systems and decision support tools to assist farmers in optimizing the allocation of limited water among crops, selection of crops based on farming situations, and adoption of appropriate alternative crops in drought years.

• Journal of the Korean association of regional geographers
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• v.7 no.3
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• pp.44-58
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• 2001

The purpose of this study is to investigate the potential water condition of Honam region according to water budget analysis. For this purpose, the eight regions (Suncheon, Gwangju, Jhangheung, Damyang, Mokpo, Yosu, Huksando, Namwon) are selected as study area. The result is as follows. (1) The water surplus indicating the potential water condition is ordered as Yosu, Sunchon, Changhung, Namwon, Damyang, Huksando, Kwangju, Mokpo. So the potential water condition of Kwangju and Mokpo is worst among study regions. (2) The high water surplus region is corresponded to high precipitation and low actual evapotranspiration legions. (3) The potential water condition is to agree with several facts about the water resource condition of Honam region. For example, large scale dam of Honam region has been constructed for Kwangju and Mokpo city. This fact indicates that the potential water condition calculated by water budget analysis is corresponded to actual water resource condition. (4) Consequently, the water budget analysis is effective method for investigating the actual water condition and establishing the water resource management of specific regions.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09a
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• pp.36-37
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• 2005

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.656-657
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• 2011

산업사회의 급속한 발전과 생활수준 향상에 따라 전력수요 및 공급전망에 대한 인식이 점차 강조되고 있다. 에너지자원이 부족한 우리나라는 전체 에너지의 약 97%를 수입에 의존하고 있으므로 전력공급의 정확한 수요예측을 통해서 안정적, 경제적으로 전력을 공급해야 한다. 2001년 전력산업구조개편에 따라 전력시장은 발전부문만 시장에 참여하여 경쟁하는 발전경쟁체제로 발전사업자의 입찰량과 전력거래소의 전력수요 예측 결과를 이용하여 시간대별 전력시장가격을 결정하는 가격결정발전 계획을 수립하고 있다. 본 논문에서는 청정 녹색에너지로 피크시간대에 발전하여 주파수 조절을 담당함으로써 전력계통에 크게 기여하고 있는 수력 발전기의 최적 입찰 전략 및 수력발전 사업계획에 활용할 수 있는 전력거래가격 전망 전략을 제시하여 수력발전사업자의 수익 증대와 전력시장 가격 안정화에 기여하고자 한다.

• Journal of Korean Society for Atmospheric Environment
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• v.29 no.6
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• pp.773-779
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• 2013

This study was performed to provide the basic data for the function of BTEX removal for compact electrostatic precipitator which are applicable to indoor environment (or closed spaces). For this purpose, the adsorption equilibrium test was conducted for BTEX of activated carbon sheet (ACS) and activated carbon (AC), and the adsorption characteristics of AC and ACS were evaluated using the Langmuir constant which was obtained from the adsorption characteristics, adsorption capacity and regression calculation. The surface area and adsorption pore volume of ACS reduced by 70% and 86%, respectively, as compared to those of AC, and the adsorption capacities of BTEX also showed a similar level. Thus, it is considered that ACS applied electrostatic precipitator is able to remove dust and BTEX simultaneously.

• Proceedings of the KIEE Conference
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• summer
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• pp.357-359
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• 2004

Fuse is the initial equipment of Protective Relay The installation standard of Fuse has been used for long time in Power Facilities. However according to the innovative development of Electric & Electronic element(=semiconductor) Technology, Protective Relay and other Power Equipments are being changed into Digitalization and Multi-Functional Convergence. In contrast with it, the installation standard of Fuse is just the same. There is a need to give careful consideration to it. This study will bear a Part of producing a safe and efficient Power by examining the current installation of primal 8f secondary 1'use in multi-functional PT of Power plant, giving a problem careful consideration and suggesting suitable countermeasures.

• Journal of Ginseng Research
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• v.22 no.3
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• pp.188-192
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• 1998

We established the model of clonogenic assay with human tumor cell line such as Calu-3 (lung carcinoma), HEC- lB (endometrial adenocarcinoma) , HEp-2 (larnyx carcinoma), Hs-5787 (breast carcinoma), K-562 (chronic myelogenous leukemia), SF-188 (brain carcinoma), SNU-1 (stomach carcinoma) and WiDr (colon carcinoma) . We investigated growth inhibition of solvent (EtOH, MeOH) and water (100$^{\circ}C$, 121$^{\circ}C$) extracts from Korean red ginseng by clonogenic assay. The results of clonogenic assay showed that EtOH extract had growth inhibition against Calu-3, SF-188 and SNU-1, MeOH extract had growth inhibition against Calu-3, Hs-5787, K-562, and WiDr, but water extract at 100$^{\circ}C$ and water extract at 121$^{\circ}C$ had not growth inhibition against used cell lines.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1047-1049
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• 2005

Hydraulic power plant is operated for peak load and frequently start-stop because of no continuous operation. So the fault can happen due to field voltage swing in the middle of starting or reactive power swing on the line. On this research, we want to analyze that this status influence on line and generator. we hope this research can contribute to the power quality improvement.