• Proceedings of the KIEE Conference
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• 1985.07a
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• pp.23-25
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• 1985

• Solar Energy
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• v.14 no.2
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• pp.61-74
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• 1994

Since the atmospheric clearness index is main factor for evaluating atmosphere circumstance, it is necessary to estimate its characteristics all over the cities in Korea. We have began collecting clearness index data since 1982 at 16 different cities and considerable effort has been made for constructing a standard value from measured data at each city. The new clearness index data will be extensively used by evaluating atmospheric circumstance analysies as well as by solar application system designer or users. From the results, we can conclude that 1) Yearly mean 63% of the atmospheric clearness index was evaluated for clear day all veer 16 cities in Korea. 2) Atmospheric clearness index of spring and summer were 63% and 64% and for fall and winter their values wre 61% and 59% respectively. So, spring and summer were higher, and fall and winter were lower then the yearly value. 3) A significant difference of atomospheric clearness index is observed between $1982{\sim}1987$ and $1988{\sim}1993$ through 16 different cities in Korea.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.78-80
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• 1991

Preliminary multiple cell stack testing was performed using three-cell stack each electrode having an active area of $100cm^2$. The stack was operated at $190^{\circ}C$, the output power was 32W at 1.8V and maximum power was 69W. It was recorded as the first stack fabricated in Korea and continuous research works on the fabrication of stack, optimization of stack performance and long run tests will be conducted.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.73-77
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• 1991

200hrs operational characteristics of the single cell in phosphoric acid fuel cell was studied. The initial performance of single cells was examined as a function of PTFE content of electrode in the range of 30 to 60 wt.%. The cell with the electrode of 40wt.% PTFE was chosen for the 200hrs operation. The cell voltage decay was found to be about 0.5mV/hr for 200hrs operation. These results of cell performance were discussed as related to the internal resistance and the exchange current density of the cell.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.212-219
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• 2009

Vietnam is endowed with multiform new and renewable energy resources. However, potential of new and renewable resources in Vietnam has not been completely assessed. Although the Government has embarked several programs to expand the use of these resources, the share of new and renewable energy in total commercial energy is still insignificant. The purpose of this study is to summarize potential and current development status as well as the prospect of new and renewable energy. Identification of barriers that are the hindrances in the development of new and renewable energy would suggest measures to future commercialization of new and renewable energy.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.190-190
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• 2016

The Water, Energy, and Food (WEF) nexus is an emerging concept for sustainable resources planning and management. The three valuable resources are inevitably interconnected, that is, it takes water to produce energy; it takes energy to extract, treat, and distribute water; and both water and energy are required to produce food. Although it is challenging to fully understand the complicated interdependency, a few studies have been devoted to interpret the concept and develop the assessment tools. The tools were mainly developed for nation-wide simulations without considering inter-basin or inter-state resources trade. This study tries to present an idea to develop and implement the WEF nexus simulation model in regional scale by advancing the existing nation-wide model with additional capability to simulate the inter-basin trade. This simulation could help local planners and engineers to determine optimal policies and infrastructure solutions to reach and ensure local demand satisfaction. The simulation model is implemented in hypothetical areas with different conditions of WEF demands and supplies. Although the inter-basin trade scenarios are simulated manually, it shows that the inter-basin resources trade could enhance the resources security for a longer time period. In future, an optimization model might be developed to provide the automatic calculation to reach optimum amount of WEF for the trade, which can be a helpful tool in decision making process.

• The KIPS Transactions:PartA
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• v.10A no.6
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• pp.757-768
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• 2003

Recently, the renewable energy resources play an important role as an energy resources of future due to an environmental pollution and lack of resources and so on. The development and diffusion of information systems related to renewable energy resources have been driven actively abroad. However, at domestic an efficient history management for renewable energy resource data and web retrieve service are not provided. Therefore, in this paper, we propose a history data management system for the renewable energy resources, which stores and manages vast history information of renewable energy resource data systematically. This system collects renewable energy resource data in the outside observation system and stores them in the history database. The stored Information is retrieved through the history query process and can be provided in various forms - table, graph, chart and counter line, etc. - on the internet. Especially, the proposed system manages the history data in real-time so the latest information is always provided to the users through the web interface.

• Solar Energy
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• v.10 no.3
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• pp.66-78
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• 1990

The purpose of this study is to provide materials necessary for planning and designing of passive solar school buildings by comparing and analyzing the satisfaction degree on old passive solar school building environment characteristics according to the school building pattern. In conclusion, passive solar systems are effective and economical when they are applied to school buildings for heating systems.

• Solar Energy
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• v.11 no.1
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• pp.87-91
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• 1991

Experimental study for the heat loss in the swimming pools using pool cover has been performed. Results of these experiments show that over the 50% of the total heat loss are reduced in these cases.

• Journal of Korean Society of Water and Wastewater
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• v.32 no.1
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• pp.1-10
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• 2018

Recently, interest in the development of alternative water resources has been increasing rapidly due to environmental pollution and depletion of water resources. In particular, seawater desalination has been attracting the most attention as alternative water resources. As seawater desalination consumes a large amount of energy due to high operating pressure, many researches have been conducted to improve energy efficiency such as energy recovery device (ERD). Consequently, this study aims to compare the energy efficiency of RO process according to ERD of isobaric type which is applied in scientific control pilot plant process of each $100m^3/day$ scale based on actual RO product water. As a result, it was confirmed that efficiency, mixing rate, and permeate conductivity were different depending on the size of the apparatus even though the same principle of the ERD was applied. It is believed that this is caused by the difference in cross-sectional area of the contacted portion for pressure transfer inside the ERD. Therefore, further study is needed to confirm the optimum conditions what is applicable to the actual process considering the correlation with other factors as well as the factors obtained from the previous experiments.