• 천문학회보
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• 제39권1호
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• pp.75.2-75.2
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• 2014

We have developed a set of daily solar flare peak flux forecast models using the multiple linear regression (MLR), the auto regression (AR), and artificial neural network (ANN) methods. We consider input parameters as solar activity data from January 1996 to December 2013 such as sunspot area, X-ray flare peak flux, weighted total flux $T_F=1{\times}F_C+10{\times}F_M+100{\times}F_X$ of previous day, mean flare rates of a given McIntosh sunspot group (Zpc), and a Mount Wilson magnetic classification. We compute the hitting rate that is defined as the fraction of the events whose absolute differences between the observed and predicted flare fluxes in a logarithm scale are ${\leq}$ 0.5. The best three parameters related to the observed flare peak flux are as follows: weighted total flare flux of previous day (r=0.5), Mount Wilson magnetic classification (r=0.33), and McIntosh sunspot group (r=0.3). The hitting rates of flares stronger than the M5 class, which is regarded to be significant for space weather forecast, are as follows: 30% for the auto regression method and 69% for the neural network method.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2008년도 추계학술대회 논문집
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• pp.315-318
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• 2008

In this paper proposed the solar tracking system to use a fuzzy control order to increase an output of the PV(Photovoltaic) array. The solar tracking system operated two DC motors driving by signal of photo sensor. The control of dual axes is not an easy task due to nonlinear dynamics and unavailability of the parameters. Recently, artificial intelligent control of the fuzzy control, neural-network and genetic algorithm etc. have been studied. The fuzzy control made a nonlinear dynamics to well perform and had a robust and highly efficient characteristic about a parameter variable as well as a nonlinear characteristic. Hence the fuzzy control was used to perform the tracking system after comparing with error values of setting-up, nonlinear altitude and azimuth. In this paper designed a fuzzy controller for improving output of PV array and evaluated comparison with efficient of conventional PI controller. The data which were obtained by experiment were able to show a validity of the proposed controller.

• 한국위성정보통신학회논문지
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• 제6권2호
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• pp.102-106
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• 2011

태양폭발, 코로나물질방출(Corona Mass Ejection, CME)등의 태양활동을 포함한 우주환경(space environment)은 결코 인간에게 우호적이지만은 않다. 특히 인공위성에게는 치명적일 수 있다. 그 중에서 정지궤도에 있는 통신위성에게는 상기와 같은 급격한 태양활동뿐만 아니라 지속적으로 끊임없이 배출되는 전자, 양성자등 플라즈마 입자들로 인해 수명이 단축되고 있다. 통신위성을 구성하는 능동부품들은 플라즈마 입자들에 특히 약하기 때문이다. 이를 방지하기 위하여 방사능 차폐(Radiation Shielind)등을 하지만 이에 대한 비용이 매우 많이 드는 것이 사실이다. 그러므로 적절한 차폐가 필요하며 이를 위해서는 우주환경의 연구가 필요하다. 본 연구에서는 저궤도부터 우주탐사용 위성까지 모든 궤도영역의 인공위성의 이상현상등을 분석한 후 이것이 태양폭발, 지자기 폭풍등 우주환경이벤트와의 연관성을 조사해보고자 한다.

• 전기학회논문지P
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• 제59권2호
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• pp.218-221
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• 2010

This paper presents energy efficiency about an electrolyser which is related with the hybrid system of solar cell and fuel cell for using the system more fully. The water electrolyser is the exact reverse of a hydrogen fuel cell; it produces gaseous hydrogen and oxygen from water. Electrolyser technology may be implemented at a variety of scales wherever there is an electricity supply to provide hydrogen and/or oxygen for virtually any requirement. Also, this paper shows optimum operating point in the electrolyser for saving cost of the electrical energy with hybrid system.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 1992년도 한국우주과학회보 제1권1호
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• pp.11-11
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• 1992

The most celebrated problem in artificial satellite theory is undoubtedly the critical inclination problem. The KITSAT-1 satellite launched by Arian 42P from Guiana in August 11, 1992 has orbital inclination close to the critical value cos-1(1/rs). In that case, there is a singularity in some perturbation terms and therefore perigee will be fixed because do/dt is equals to zero. But actually the long periodic behaviour in argument of perigee, u is affected by luni-solar gravity andrelativistic effect, etc. Luni-solar gravity induces periodic perturbations in allorbital elements except the semi-major axis, and secular variations in 0, u and M.We have obtained nodal rate and inclination variations in case of the KITSAT-1.In this paper, we will also show the geopotential perturbations in 0, M of the Satellite in CIUding J2, J3, J4, J22 terms.

• 한국태양에너지학회 논문집
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• 제30권1호
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• pp.19-24
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• 2010

At the altitudes above 3km, the wind is three to four time faster and less variable than at the current MW sized wind turbine hub height of around 100m. In addition, power generation from wind turbines installed on the ground is intermittent because local wind conditions are affected by local topography and artificial structures. The wind energy researchers and engineers are now looking for revolutionary ideas to utilize high altitude wind resources in-creasing the capabilities of wind turbine installations. This article presents and discusses several concepts for wind energy exploitation from wind at high altitudes. The concepts presented in this paper make use of lifting bodies, called wings or kites, connected to a tether that stetches into the higher regions of the atmosphere.

• 대한가정학회지
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• 제42권1호
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• pp.99-113
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• 2004

To protect farmers from solar radiation and UV, the movable sunshade tent was designed and its protection efficiency was measured in the artificial chamber and outdoors. Sunshade tent and the existing farmer's hat were examined. The results were as followes； Heart rate, total body weight loss and temperature of clothing microclimate on the chest and the back were lower in using sunshade tent than those in wearing existing hat in two experiments. In subjective sensation, subjects answered to feel significantly hotter and more uncomfortable in wearing existing hat in two experiments. Rectal temperature was significantly lower using the sunshade hat in experiment at outdoors(p<0.001).

• 한국태양에너지학회 논문집
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• 제27권2호
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• pp.95-101
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• 2007

The surface changes due to urban expansion and the increase of artificial heat releases have brought significant climate changes such as heat island phenomenon in urban area. Furthermore, these changes also have brought serious problems such as air temperature increase, wind changes, and air pollution in urban area. Comprehensive analytical technologies considering various effects are required to analyse complicated mechanism of climate changes, and review the efficient measures. In this research, the effect of the urban expansion in Tokyo and Bangkok area on urban environment will be discussed. By using CFD, urban development and the mechanism of global warming and wind change are studied in those two cities. As a result of numerical research, the surface changes of city could bring the environmental changes in urban area.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.35-36
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• 2008

In this paper, we studied the long term durability estimation for crystalline photovoltaic module while exposing to mechanical stress. Solar cell and PV module have many different kinds of stresses from cell to module fabrication. For this reason, some solar cell shows micro crack that decrease crystallization. In here, we expose artificial mechanical load on surface of PV module. Through this, the periodic external force on PV module might give an negative effect. The further analysis is described in the following paper.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2022년도 춘계학술대회
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• pp.255-258
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• 2022

최근 환경 오염이 지속되면서 신재생 에너지에 대한 사람들의 관심이 높아지고 있다. 제주 지역은 태양광, 태양열, 바이오, 풍력 발전 등 신재생 에너지 발전이 많이 이루어지고 있지만, 그에 비하여 관련 데이터의 개방과 분석 사례는 부족한 상황이다. 이에 본 연구에서는 전 세계 데이터 사이언티스트(Data Scientists)들이 활동하고 있는 캐글(Kaggle) 플랫폼을 활용하여 태양광 생산량과 관련된 변수를 추출하고, 데이터에 적용할 수 있는 머신러닝(Machine Learning) 기법을 탐구하여 머신 러닝 설계를 위한 제주 지역의 태양광 발전 데이터셋(Dataset) 형태(Form)를 제시하고자 한다. 구체적으로는 캐글 데이터 플랫폼을 활용하여 태양광 에너지 분석을 진행한 후 제주 지역 태양광 데이터 수집에 대한 보완점을 제안할 수 있다. 이러한 시도는 제주 지역의 태양광 산업의 발전을 위한 데이터 분석에 활용이 가능할 것으로 기대할 수 있다. 즉, 현재 개방되어 있는 제주 지역의 태양광 발전 데이터셋 형태를 인공지능(Artificial Intelligent) 분석을 위한 머신러닝에 적합한 형태로 구축이 될 수 있도록 제안할 수 있다. 이를 통하여 제주 지역 태양광 산업의 발전의 효율을 높이는 방안을 마련하는데 기반 연구가 될 것이다.