• Journal of the Korean Solar Energy Society
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• v.26 no.3
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• pp.45-51
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• 2006

Recently, various kinds of daylight system are recognized as an important and useful strategy in energy-efficient building designs. However, a large amount of direct sunlight can make many problems. Therefore, it is necessary to control daylighting through louver systems for high quality visual environment. The purpose of this study is to analyze daylighting performance in the reading room of a library according to different azimuths and louver systems. The results evaluated daylight performance based on the RADIANCE lighting software.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.495-498
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• 2008

Photocatalytic water splitting into $H_2$ and $O_2$ using semiconductors has received much attention, especially for its potential application to direct production of $H_2$ for clean energy from water utilizing solar light energy. Since the report of Fujishima and Honda on the water splitting by photoelectrochemical cells, numerous different semiconducting materials have been used as photocatalysts for hydrogen generation from water. Among them, platinized titania significantly accelerates hydrogen production from water. For geometrical improvement of $TiO_2$ particle, porous $TiO_2$ structure was proposed and studied such as nanofiber, nanorod and nototubes. This research focuses on finding out the optimum temperature and electrolyte to produce $H_2$ by solar water splitting.

• Membrane and Water Treatment
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• v.5 no.4
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• pp.251-263
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• 2014

The study contributes in the treatment of waste generated by the textile complex cotton of Draa Ben Khedda, Algeria. The azo dye "Direct Red Solophenyle 4GE" represents the base particle of the discharges and electrocoagulation with nanofiltration are used as a means of treatment. The solar photovoltaic is suitable for electrochemical process to reduce the energy cost. Several study parameters are considered in this work. The electrocoagulation batch gives the best reduction 37% for a dye concentration of 7.21 mg/L ($[NaCl]_{added}$=1g/L; $j=25.2mA/cm^2$). Coupling methods (electrocoagulation-nonofiltration) gives a complete discoloration rejecting concentration 52.4 mg/L (pHi = 7.6, $[NaCl]_{added}$=3g/L, $j=2.13mA/cm^2$). The result shows the coupling efficiency with a reduced amount of resulting slurry at the end of treatment.

• Journal of the Korean Solar Energy Society
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• v.34 no.2
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• pp.91-97
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• 2014

This paper presents the modeling and contingency analysis of Jeju power system. For the analysis of contingency with simulation, thermal power plants, current source type HVDC systems, wind farms, STATCOMs and Jeju power load are modeled by PSCAD/EMTDC program. And three kinds of simulation are carried out. Firstly, two STATCOMSs are in normal operation. Secondly, one STATCOM is in fault. Lastly, all of STATCOMs are in fault. These comparative studies will be useful for evaluating the effectiveness of STATCOM to stabilize for the Jeju power system.

• Proceedings of the KIPE Conference
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• 2003.11a
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• pp.206-209
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• 2003

This paper deals with stand-alone PV power generation system with charge and discharge controller for the LED road sign. Main power source of PV system are generally solar cell and battery. Therefore PV system can be classified into variable types in accordance with connection type between battery and solar sell. Mainly used on of them is direct connection type which has advantage such as simple structure and simple controller. To verify the proposed PV generation system for the LED road sign, the detail simulation and experiment results indicate that operating characteristics are verified by experiment with a laboratory prototype in this paper.

• Proceedings of the Membrane Society of Korea Conference
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• 2004.05b
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• pp.1-8
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• 2004

Ion-conducting polymer electrolyte membranes (PEMs) have recently used in developing fuel cell or solar cell for portable, mobile and residential applications [1]. Polymer electrolyte membrane fuel cell (PEMFC), direct methanol fuel cell (DMFC), alkaline electrolyte fuel cell (AFC) and dye-sensitized solar cell have been employing the ion-conducting PEMs to complete their electrical circuits to produce electricity.(omitted)

• Journal of the Semiconductor & Display Technology
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• v.13 no.4
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• pp.43-48
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• 2014

Two-level inverter has some disadvantages like high harmonics contained in the output current, efficiency limit and stress to switching device as IGBT and FET. Many researches have reported multi-level inverter to complement two-level inverter of problems. In this paper, we suggest MPPT algorithm of multi-string three-level solar inverter that considered nowadays. We added midpoint controller in order to implement the MPPT algorithm because the three-level inverter has to need midpoint controller and procured the stability of direct current link. We verify the superiority of multi-string T-Type inverter and the algorithm we suggested with solar irradiance variation experiment and MPPT efficiency measurement. The MPPT efficiency was confirmed with a high efficiency more than 99.97%.

• Transactions on Electrical and Electronic Materials
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• v.17 no.1
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• pp.21-24
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• 2016

A junction box used in a 3 kW photovoltaic power generation system plays a role in collecting and supplying the direct current voltage produced by photovoltaic modules to an inverter. It is also used for facilitating maintenance checks and protecting the module and inverter by keeping the voltage constant. As for the junction box, using it in a parallel connection creates a difference between the setup modules. In order to compensate, an inverse voltage diode is used. But the high-power created through the solar generator can be delivered to the inverter through the inverter regularly. Therefore, a component can break down due to excess heat. And consequently short circuits and electric leakage occurs. In this study, using a junction box that enabled the bypass of high electric power, it was possible to reduce heat generation by approximately 35℃ when compared to a standard junction box.

• Journal of Environmental Impact Assessment
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• v.21 no.1
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• pp.219-227
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• 2012

Daily solar radiation is essential for water resources planning and environmental impact assessment. However, radiation data is not commonly available in Korea other than in big cities, and there has been no direct measurement for rural areas where water resources planning and environmental impact assessment is usually most needed. In general, missing radiation data is estimated from nearby regional stations within a certain distance, and this study compared two dominant methods (modified Angstrom equation and transmittance interpolation method) at six stations in Nakdong River watershed area. Two methods shows a similar level of accuracy but the transmittance interpolation method is likely to be superior in that there is no need for any measurement element since the modified Angstrom equation require the sunshine hour measurement. This study will contribute to improve water resource and water quality management in Nakdong River watershed.

• Journal of Korea Society of Digital Industry and Information Management
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• v.14 no.4
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• pp.163-168
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• 2018

In this paper presents comparison of performance of flexible solar cells construction applied to curtain walls. The proposed paper compares power generation for curtain walls of various shapes using flexible PV. Through the comparison of performance, the power generation was compared by installing various types of flexible PV on the air layer of double windows. By comparing the measured power generation, it is possible to find an optimal flexible PV shape that can be applied to a curtain wall. Flexible PV installation was divided into diagonal, S and W shapes. As a result of comparison, the amount of power generation when there was no flexure of flexible PV was large. Also, as the angle with the light source increased, the power generation decreased. Therefore, it is necessary to study the structure which can fix the PV more than the flexible PV and to be able to direct the sun without distortion.