• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1992년도 가을 학술발표회 논문집
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• pp.58-61
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• 1992

Water potential which controls miosture movement in concrete is a kind of stress which causes concrete shrinks or expands. Therefore, there is a straightforward relationship between the water potential and the shrinkage strain. Explicit equations which show the relationships between the two parameters were derived through rational process. Two micro mechanisms among three shrinkage mechanisms were considered in the theory. Thermocouple psychrometer were embedded in a concrete slab to measure the water potential and also to find a correlation with the shrinkage. The test results prove the validity of the theory, and show the way to utilize the delived equations.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2003년도 학술발표논문집
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• pp.531-534
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• 2003

A model using a nonlinear programming technique was applied for allocating the optimal water depending on storage level changes of the Sumjin dam. The objective function of optimization model was set up to maintain the storage at target level, to satisfy the water demand, and to maximize the hydropower production. In this way, the water allocation as to target level and instream flow was optimized and compared with historical operational data.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2002년도 학술발표회 발표논문집
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• pp.33-36
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• 2002

The purpose of this study is to develope a indicator for agricultural water use. Agricultural water is challenged by the increase of water use in the sectors of urbanization and industry and social pressure to use water in sustainable and environmentally sound way. The development of agricultural environment indicators is divided into 13 sectors, among which agricultural water use indicators include amount and intensity of agricultural water use, efficiency of agricultural water use, shortage or surplus of water use, water stress, etc.. Agricultural water use indicators provide basic data for sustainable and environmentally sound agricultural development, and also help policy decision makers to solve water shortage problems through water policy and water management measures by making the most of the total available water resources.

• 건축사
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• 통권606호
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• pp.92-101
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• 2019

• 한국환경교육학회지:환경교육
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• 제3권1호
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• pp.125-129
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• 1992

The purpose of this study was to investigate the condition of school water supply systems and to provide a way to supply safe and sanitary water in schools. In 1991 present, 56.9% of schools in the whole nation are provided with water supply system. And in urban schools, the percentage of small water supply system was larger than that in city. In the survey on water quality of supply water in Seoul city, the items violating the water quality standard were total bacteria, Zinc and Manganse. For supply the safe drinking water changing the old water mains and executing periodical water quality surveys are needed in addition regulations on school supply water and sanitation are also necessary to the drinking water management in schools.

• 한국환경교육학회지:환경교육
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• 제22권4호
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• pp.81-94
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• 2009

This study was intended to develop the STS module regarding conservation of water resources, called "A Project for the Conservation of Water Resources". Since each theme consisted of 2 subject activities, they had total 8 subject activities. Developed STS module was applied to 113 male students of 11th grader of D High School in Incheon. After they received 8 periods of the developed STS module, the environmental sensitivity and environmental conservation behavior and the interest of the affective domains related to science were determined. Results were as follows; Four themes of this module were 'What are the water resources?', 'What is a main cause for the water pollution?', 'A drinking water? or non-drinking water?' and 'Making UCC for the water resources'. Since each theme consisted of 2 subject activities, they were for total 8 periods. Developed STS module was found to be appropriate for the STS and they could be applied to the classroom easily. Students who were instructed according to the developed STS module showed that there was a statistically significant enhancement in the environmental sensitivity and environmental conservation behavior and in the area of interest of the affective domains related to science. Students who were instructed according to the developed STS module showed positive responses to the instructional methods by STS. Based on students' interview, they revealed that they were impressed with the hands-on activities and the process of subject activities. Instruction with STS module seemed to be more appropriate way of teaching compared to the traditional way of teaching. However, it will be necessary to develop more modules or programs which could be linked from the elementary school level to the high school level and to use them consistently in order to maximize their effects.

• 상하수도학회지
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• 제13권1호
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• pp.134-139
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• 1999

This study was conducted to determine the effects of water aggressivity on the corrosion in a recirculating pipe loop systems. As the pH was increased in the range of pH 6.0~8.5, water aggressivity was decreased. Zine and iron concentration of water adjusted by pH were lower than those of tap water and water adjusted by alkalinity and calcium hardness. The major elements of corrosion deposit analyzed by EDS(Energy Dispersion Spectrophotometer) were zinc and calcium. In conclusion, we suggest that in corrosion control practice in the water works industry, increasing the pH of the water can serve as a way of controlling the solubility of metal ions release from water distribution systems.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.167.1-167.1
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• 2011

Sustainable energy generation is becoming extremely imperative due to the expected limitations in current energy resources and to reduce pollution. Especially, because of its considerable energy potential, ocean wave energy has been investigated with regard to power generation. To develop large high power wave generator system, it is important to make a small scale proto type and to test that. Thus the objective of this research is to examine the characteristics of a mechanically excited generator system having small power capacity experimentally. The water reservoir (4 m length, 1.5 m width and 1.8 m depth) having a wave maker to make arbitrary height and period of the water wave was made. The proto type consists of three main parts; a buoy, rack-pinion base one-way mechanism, and a wave generator(Fig.1). The water wave is going up and down and the hexahedron buoy is following the wave. The rack gear attached to the buoy is also going up and down to roll the pinion connected to an electric generator then it produces electricity. The experiments were performed with several conditions of water waves, and the power outputs over 30 W could be measured for some conditions. In future works, to achieve higher performance for the proto type, the effects of primary parameters (buoy shape and mass, etc.) on the system efficiency will be identified.

• 환경위생공학
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• 제14권4호
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• pp.77-84
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• 1999

Most river quality problems are generated by pollutants which are discharged into the river as a consequence of human activities. And eutrophication occurs when water is over enriched with nutrients, principally nitrate and phosphate. Both these nutrients are found in many waste products, especially sewage even when the waste is treated. Eutrophication is concerned in lakes, but it also causes problems in river. Wide growth of Phytoplankton in rivers, leads to blockage of channels, but the main concern is deoxygenation because of the increase in plant life's demand for oxygen in revers. Fish, plant and animals die due to lack of oxygen. The increase of algae floating on the tops of water looks ugly and has attracted public attention and concern in recent years. One way of controlling eutrophication is to restrict the amount of waste carrying nitrate or phosphate from entering the water in the first place. another way is to remove it from the water after it has been entered. This study was carried out to investigate on the trophic state, nutrients and Chlorophyll-a concentration in the Han River. The results were as follows:1. Concentrations of total nitrogen were 2.208~9.221(5.133)mg/$\ell$2. Concentrations of total phosphate were 0.045~0.614(0.195)mg/$\ell$3. Chlorophyll-a concentration were $0.0-25.3(9.6)mg/m^3$.4. The correlation coefficient between T-P and Chlorophyll-a concentration was r=-0.856 at Sungsan sampling site.5. The correlation coefficient was r=-0.578~-0.767, between Paldang Dam outflow and Chlorophyll-a concentration at all sampling sites.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2009년도 학술발표회 초록집
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• pp.1945-1949
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• 2009

It is fact that many research is advanced about management and security of water resources according to serious problem which is raising its head that conservancy and management of water resources development of population and industry. Ground water of water resources is the source of water resources security with surface water, so it have to be continuous exploitation and research however, until now it researched in separate way from surface water, and it become connect each other for the research in actual condition in recent times. The research analyzed the recharge at the SWAT model, interpreted by used GMS/MODFLOW model for ground water flow change.