• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.5B
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• pp.497-502
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• 2009

The wastewater treatment by photocatalyst decomposes pollutants directly in water, and it is easy to decompose indecomposable organics and inorganic. and Especially, it has an advantage that there is no secondary production of pollutants. However, there will be many problems which are generated depending on the type of photocatalyst. The type of rotating photocatalyst minimizes previous problems, and advanced oxidation processes is possible by the application of rotating disc method. The consideration of the characteristics about various designs and operation factors is needed for the application of rotating photocatalyst system. In this study, rotating photocatalyst was manufactured for rotating disc method by fixing of $TiO_2$. The operation factors were derived for the wastewater treatment by the reaction of rotating photocatalyst. The contained quantity of $TiO_2$ was limited about 70%. The more the contained quantity of $TiO_2$ was increased, the more the treatment rate was continually increased. The optimum rotating photocatalyst was R4, and the contained quantity of $TiO_2$ was 36.8%. The more the exposed amount of UV is increased, the more the decomposition effect of TCODcr was continually increased. However, the adequate strength of light source must be determined by the consideration of economical efficiency. The more the speed of rotating photocatalyst is increased, the more treatment efficiency was increased. When UV lamp was not submerged in reactor, the wastewater treatment was efficient in the order of the depth of water 50%, 30%, 10%, 70%, 100%. This study is a basic research for the development of a system which treats organics in solar light.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.451-451
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• 2009

CdTe는 에너지밴드갭이 1.45eV인 직접천이헝 II-VI 화합물 반도체로서 높은 광홉수율과 가시광 영역의 에너지밴드캡으로 태양전지, x-선 검출기 등에 널리 사용되고 있다. 본 연구에서는 Metal Organic Chemical Vapor Deposition (MOCVD)으로 Si 기판위에 CdTe 에피 박막을 성장 하고자 하였다. Cd, Te의 금속유기 화합물로는 Dimethylcadmium(DmCd)과 Diisopropyltellurium(DIPTe)을 사용하였다. 기판으로는 Si 을 사용하였으며 박막성장 온도를 $360^{\circ}C\;{\sim}\;500^{\circ}C$로 제어하여 에피박막이 형성되는 조건을 얻고자 하였다. $360^{\circ}C$, $450^{\circ}C$에서 성장된 CdTe박막은 다양한 방향이 존재하는 다결정 구조 였으며 $500^{\circ}C$의 경우 단결정 에피 박막 성장이 이루어졌음을 확인하였다. 본 연구를 통한 CdTe 에피박막은 기존의 열증착 등으로 제조되는 다결정 CdTe 박막과 비교하여 높은 에너지변환 효율을 얻을 것으로 기대된다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.10
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• pp.95-100
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• 2014

To solve the problem of conventional fossil energy, utilization of renewable energy is growing rapidly. Solar energy as an energy source is infinite, and a variety of research is being conducted into its utilization. To change solar energy into electrical energy, we need to build a solar power plant. The efficiency of such a plant is strongly influenced by meteorological factors; that is, its efficiency is determined by solar radiation. However, when analyzing observed generation data, it is clear that the generated amount is changed by various factors such as weather, location and plant efficiency. In this paper, we proposed a solar power generation prediction algorithm using geographical factors such as latitude and elevation. Hence, changes in generated amount caused by the installation environment are calculated by curve fitting. Through applying the method to calculate this generation amount, the difference between real generated amount is analyzed.

• Journal of Energy Engineering
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• v.25 no.4
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• pp.62-73
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• 2016

Daylighting systems offer substantial advantages over conventional ones in illuminating the building interior. Especially, considering that lighting accounts for about 28% of total energy consumption in buildings, the use of daylighting systems deem very important in lessening the dependency on artificial lighting. This work has carried out a survey and analysis to explore the characteristics and current status of various daylighting systems with solar tracking features recently introduced in Korea.

• Proceedings of the KIPE Conference
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• 2003.07b
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• pp.949-952
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• 2003

인터넷으로 표현되는 디지털 세상은 빠른 속도로 변하는 삶 전체에 영향을 미치는데, 특히 산업체에서의 업무와 일하는 방식을 바꾼다. 인터넷과 웹 접속 기술은 현재의 업무 과정을 개선하고, 전통적인 제조 기업의 생산성과 관리 효율을 극대화한다 본 논문에서는 이러한 발전 설비의 안정성과 원거리 모니터링의 신뢰성과 PV시스템의 제어에 관한 것이다 그리고 PV시스템의 센서 모니터링 데이터와 간접적인 제어를 설계하였다. 전통적인 모니터링 시스템은 특수한 하드웨어나 소프트웨어에 의존한다 모니터링 시스템의 기본적인 목표는 사용자가 휴대용 단말기를 통해 모니터링과 제어를 할 수 있게 하는 것이다. Labview GUI를 이용하여 설계한 모니터링 시스템은 윈도우 2000을 운영체제로 한 IBM PC를 사용하였고, TCP/IP 프로토콜에 기본을 두었다. 이러한 모니터링 시스템의 이점은 사원의 지출(급여)를 줄이고 지구 어느 곳에서든 발전 시스템을 인공위성을 통하여 모티터링과 제어를 할 수 있다.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.484-485
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• 2011

반사방지(Anti-Reflection, AR) 특성은 태양전지, LED, 광검출기 등의 광전소자와 디스플레이의 효율과 투과도를 향상시키기 위해 적용되고 있다. 또한 최근에 네비게이션, 스마트폰의 보급 증가로 인해 소형 디스플레이에 지문방지와 동시에 반사방지 기능을 갖는 필름이 사용되고 있다. 현재 적용되고 있는 반사방지 필름은 다층박막 코팅으로 형성된 필름[1]으로 생산단가와 박막의 내구성 및 신뢰성에 문제점을 가지고 있다. 이런 문제점을 해결하기 위해 나노구조로 제작 되는 반사방지 필름에 관한 연구가 활발히 진행되고 있다[2]. 나노구조로 형성된 반사방지 구조는 moth-eye 구조라고 하며, 기본 원리는 원뿔 형태를 형성된 나노 구조를 통해 공기와 나노구조 사이의 유효 굴절률을 서서히 변화시켜 반사를 줄이는 것이다. 그러므로 moth-eye 나노구조는 파장 이하의 pitch와 파장 크기의 높이를 갖도록 구조가 제작되어야 한다[3]. Photo-lithography[4], e-beam lithography[5], interference lithography[6], dip-pen nanolithography[7], hybrid nano-patterning lithography[8] 등 여러 가지 방법으로 나노 구조를 제작하고 있으나, 네비게이션이나 스마트폰 등에 적용될 수 있는 대면적으로 제작하기 위해서는 roll-to-roll printing과 같은 대면적 공정을 이용하여 제작하는 것이 필요하다. 본 논문에서는 원통형 알루미늄 rod에 양극산화를 통해 다공성 AAO(anode aluminium oxide) template를 제작하고, roll-to-roll printing 기술을 사용하여 moth-eye 나노구조를 갖는 반사방지 필름을 제작하는 것에 대해 기술하였다.

• Journal of the Semiconductor & Display Technology
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• v.13 no.2
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• pp.37-44
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• 2014

In this study, the performance of dye-sensitized solar cells with different thickness of the photelectrode film was simulated by using the electron-diffusion differential model. Through this simulation, the relationships between the thickness of the photoelectrode film and the performances (open-circuit voltage, short-circuit current density, and overall photoelectric-conversion efficiency) of cells were understood and the performances with different thickness of the photoelectrede film were also examined. For considering the refractive index in the liquid electrolyte and exploring the scattering effect of titanium dioxide particles with different sizes using the Mie light-scattering theory, the highest scattering effect of each particles was found out and the optimal size of the titanium dioxide particle was determined for light scattering in the photoelectrode film of dye-sensitized solar cell. Through experiment, the mixed titanium dioxide cell was better than the single titanium dioxide cell and generated a higher overall conversion efficiency because the optimal titanium dioxide particles in the phoelectrode film as light scattering.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.64 no.1
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• pp.1-6
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• 2015

Factors that have influence on solar power generation are specified into three aspects such as meteorological, geographical factors as well as equipment installation. Meteorological factors influence the most among the three. Insolation, sunshine hours, and cloud directly influence on solar power generation, whereas temperature and wind speed have impacts on equipment installation. This paper provides explanation over temperature-wind speed equation by calculating influence of temperature and wind speed on equipment installation. In order to conduct a research, pyranometer, anemometer, air thermometer, module thermometer are installed in 2MWp solar power plant located in South Cholla province, so that real-time meteorological data and generating amount can be analyzed through monitoring system. Besides, if existing and new methods are applied together, accuracy of prediction for generating amount is improved.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1997.10a
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• pp.88-92
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• 1997

Power conversion system must be increased swiching frequency in order to achieve a small size, a light weight and a low noise, However, the swiches of converter are subjected to high switching power losses and switching stresses. As a result of those, the power system brings on a low efficiency. In this paper, the authors propose a DC-DC boost converter of high power by partial resonant switch method (PRSM). The switching devices in a proposed circuit are operated with soft swiching and the control technique of those is simplified for switch to drive in constant duty cycle. The partial resonant circuit makes use of a inductor suing step up and a condenser of loss-less snubber. Also the circuit has a merit which is taken to increase of efficiency, as if makes to a regeneration at input source of accumulated energy in snubber condenser without loss of snubber in conventional cirvuit. The result is the the switching loss is very low and the efficiency of system is high. The proposed converter is deemed the most suitable for high power applications where the power switching devices are used.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.10
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• pp.1423-1427
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• 2014

Quantity of the solar power generation is heavily influenced by weather. In other words, due to difference in insolation, different quantity may be generated. However, it does not mean all areas with identical insolation produces same quantity because of various environmental aspects. Additionally, geographic factors such as altitude, height of plant may have an impact on the quantity. Hence, through this research, we designed a system to predict efficiency of the solar power generation system by applying insolation, weather factor such as duration of sunshine, cloudiness parameter and location. By applying insolation, weather data that are collected from various places, we established a system that fits with our nation. Apart from, we produced a geographic model equation through utilizing generated data installed nationwide. To design a prediction model that integrates two factors, we apply fuzzy algorithm, and validate the performance of system by establishing simulation system.