• Journal of Korean Society of Water and Wastewater
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• v.30 no.3
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• pp.313-319
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• 2016

In this study, the performance experiment was conducted to compare the permeate flux of hollow fiber Vacuum Membrane Distillation module according to leak problem between module housing and membrane bundle. For the permeate flux performance experiment of the two Vacuum Membrane Distillation modules, the Lab-scale experimental equipment was built in the capacity of $1m^3/day$. The performance test of the two Vacuum Membrane Distillation modules were analyzed according to the feed water conditions. As a result, it was analyzed that the leak VMD module decreased about 14% of permeate flux than normal VMD module.

• Solar Energy
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• v.8 no.2
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• pp.26-38
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• 1988

If proper design and selection of the working fluid are made the power generation system of temperature difference could achieve more efficient results than others. This paper is to analysis the production of its power generation due to several parameters. Making the power generation system, the characteristics of power output are investigated to obtain its basic data for design. This results of this experiment are as follows. 1. The most proper working fluid in the system is Freon-22 having high stability and difference between the outlet pressure, $P_E$ of evaporator and outlet pressure, $P_c$ of Condenser. 2. With the increase of temperature difference between evaporator and condenser, the output in the system increases linearly. 3. The generation efficiency is largely dependent on the type or form of propeller, nozzle and optimum design of heat exchanger.

• Journal of the Korean Solar Energy Society
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• v.23 no.4
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• pp.71-80
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• 2003

The purpose of this study is to analyze the window area ratio distribution of building facade in Tokyo metropolitan area. The survey was carried out in Marunouchi, Kanda, Kasai and Todoriki district. The results of this study were as follows; to propose of window area ratio production method, analyzed and surveyed window area ratio of each district building-used and to compared every wall window area ratio of building. Every wall window area ratio of office district is $20\sim40%$, ones of non-office district is 15% or 35%. Residential area results are every wall window area ratio of apartment is 35%, ones of a house is 15%. To increase of office building to appear that Kanda, Kasai added window area ratio. But, Marunouchi, Todoriki wad not this tendency. Above mentioned results are made out database.

• Journal of the Korean Institute of Intelligent Systems
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• v.26 no.5
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• pp.351-360
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• 2016

Rapid population growth with high living standards and high electronics use for personal comfort has raised the electricity demand exponentially. To fulfill this elevated demand, conventional energy sources are shifting towards low production cost and long term usable alternative energy sources. Hybrid renewable energy systems (HRES) are becoming popular as stand-alone power systems for providing electricity in remote areas due to advancement in renewable energy technologies and subsequent rise in prices of petroleum products. Wind and solar power are considered feasible replacement to fossil fuels as the prediction of the fuel shortage in the near future, forced all operators involved in energy production to explore this new and clean source of power. Presented paper proposes fuzzy logic based Energy Management System (EMS) for Wind Turbine (WT), Photo Voltaic (PV) and Diesel Generator (DG) hybrid micro-grid configuration. Battery backup system is introduced for worst environmental conditions or high load demands. Dump load along with dump load controller is implemented for over voltage and over speed protection. Fuzzy logic based supervisory control system performs the power flow control between different scenarios such as battery charging, battery backup, dump load activation and DG backup in most intellectual way.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1442-1442
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• 2011

Increase the cost of electricity generation compared to (30 million won / KW) can only be used in standalone or distributed, but in the same area of photovoltaic conversion efficiency is much higher than with a large Stirling engine development has economic value of the infinite. Commercialization 25KW level or above Stirling engine production or introduction is necessary solar power in the various application and effect analysis for further empirical studies or regional energy projects, demonstration of business expansion and conductor, Stirling engines.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2001.05a
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• pp.285-302
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• 2001

At the present time the desalination technology of sea water for portable water in islands employs the RO method. The technology which needs complicated pretreatment processes with various chemicals can generate secondary water pollution and the high maintenance costs such as replacements of filters and membranes make islanders nearly impossible to operate. The MVRS technology for desalination of sea water however has several advantages such as constant production of quality portable water and capability of managing broad operating load. The variable-speed turbo-type vapor compressors employed in the system can utilize wind energy which is abundant in most Korean islands. Salt as a by-product can be produced by applying solar energy to the salt-concentrated waste water from the system. This paper discusses the relating topics such as technical and economical viabilities of the new MVRS desalination system for the production of portable water and salt as a by-product using new & renewable sources of energy.

• Journal of the Korean Solar Energy Society
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• v.31 no.5
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• pp.1-8
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• 2011

In this study, we performed a sensitivity analysis to see how the true north error of a wind direction vane installed to a meteorological mast affects predictions of the annual-average wind speed and the annual energy production. For this study, two meteorological masts were installed with a distance of about 4km on the ridge in complex terrain and the wind speed and direction were measured for one year. Cross predictions of the wind speed and the AEP of a virtual wind turbine for two sites in complex terrain were performed by changing the wind direction from $-45^{\circ}$ to $45^{\circ}$with an interval of $5^{\circ}$. A commercial wind resource prediction program, WindPRO, was used for the study. It was found that the prediction errors in the AEP caused by the wind direction errors occurred up to more than 20% depending on the orography and the main wind direction at that site.

• Journal of The Korean Astronomical Society
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• v.32 no.2
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• pp.137-147
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• 1999

Recent studies show the importance of understanding three-dimensional magnetic reconnect ion on the solar surface. For this purpose, I consider non-coplanar magnetic reconnection, a simple case of three-dimensional reconnect ion driven by a collision of two straight flux tubes which are not on the same plane initially. The relative angle e between the two tubes characterizes such reconnection, and can be regarded as a measure of magnetic shear. The observable characteristics of non-coplanar reconnection are compared between the two cases of small and large angles. An important feature of the non-coplanar reconnect ion is that magnetic twist can be produced via the re-ordering of field lines. This is a consequence of the conversion of mutual helicity into self helicities by reconnection. It is shown that the principle of energy conservation when combined with the production of magnetic twist puts a low limit on the relative angle between two flux tubes for reconnect ion to occur. I provide several observations supporting the magnetic twist generation by reconnection, and discuss its physical implications for the origin of magnetic twist on the solar surface and the problem of coronal heating.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.402-405
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• 2008

SunPower's corporate mission is to reduce the installed cost of solar electricity 50% by 2012. As part of that mission, the company is continually exploring novel technologies that might enable progress towards the goal. This paper describes SunPower's efforts to decrease the levelized cost of electricity for solar power plants through the use of bifacial cell and system technology. The results of the first production run of SunPower bifacial cells and modules are presented. Future bifacial system development plans are reviewed.

• Rapid Communication in Photoscience
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• v.2 no.3
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• pp.85-88
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• 2013

Silica nanoparticles were synthesized with various silane coupling agents to make specific pathway of electrons and anti-recombination system when solidifying liquid electrolytes. In this study, we used an appropriate method of synthesis for activated silica nanoparticles and silane coupling agents with 3-(triethoxysilyl)propionitrile, Trimethoxy[3-(methylamino)propyl]silane, Triethoxyoctylsilane, and octadecyltrimethoxy silane. Dye-sensitized solar cells using solidified electrolytes with silica nanoparticles exhibit comparatively excellent efficiency, ranging from 2.3 to 7.0% under similar conditions.