• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.10a
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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.

• Journal of Satellite, Information and Communications
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• v.6 no.2
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• pp.102-106
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• 2011

Space Environment including Solar activities such as Solar explosion, Corona Mass Ejection(CMS) is always not friendly for human. Especially it may be fatal to artificial satellites. The lifetime of geostationary communication satellites are reducing due to plasma such as electrons, protons etc. emitting from Sun. This is because the active components constituting communication satellite are easily affected by plasma. Even though the radiation shielding on the components can be a way to prevent, the cost will be high. So the appropriate shielding is necessary and the study on space environment is also. In this study spacecraft anomalies will be investigated from low earth orbit to deep space spacecraft and the correlation between spacecraft anomalies and space environment events including space explosion, geomagnetic storms etc is analyzed.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.59 no.2
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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.

• Bulletin of the Korean Space Science Society
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• 1992.10a
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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.

• Journal of the Korean Solar Energy Society
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• v.30 no.1
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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.

• Journal of the Korean Home Economics Association
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• v.42 no.1
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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).

• Journal of the Korean Solar Energy Society
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• v.27 no.2
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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.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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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.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.255-258
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• 2022

As environmental pollution continues, attention on renewable energy is on the constant rise in recent days. Although various kinds of renewable energy such as solar, wind power and biomass energy have been generated in Jeju, opening and analyzing cases on related data seem insufficient. Therefore, this study is being conducted to deduce the variables which have high relation with solar panel&s output and to understand machine learning methods that can be applied to solar power generation data by utilizing Kaggle platform, which is actively used by a number of scientists. Then, it is planned to propose a form of solar power generation dataset by researching machine learning methods that could be applied to the data. To be specific, analyzing solar power generation data with the Kaggle platform, this study will provide complements on gathering solar power data in Jeju. This study is anticipated to be utilized on data analysis for developing the solar power industry in Jeju. That is, this study is expected to reveal the room for improvement inherent in existing open datasets in Jeju, so that they could be constructed in a suitable form for machine learning for AI analytics. Through this process, a method to increase efficiency of solar power generation is anticipated to be prepared.

• Journal of Astronomy and Space Sciences
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• v.10 no.1
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• pp.17-27
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• 1993

The orbit characteristics and perturbation effects of an artificial satellite with critical inclination have been studied. The critical inclination problem in artificial satellite theory is treated as Ideal Resonance Problem(IRP). The KITSAT-1 satellite launched by Arian 42P at Guiana in August 11, 1992 has orbital inclination close to the critical value cos-1(1/√5). In that case, there is a singularity in some perturbation terms and perigee of the orbit is fixed because d$\omega$/dt is theoretically equal to zero. But actually the long periodic behaviour in argument of perigee, $\omega$ shows a small oscillation. The causes of the oscillation and the relativistic effect in IRP have been studied and applied to the KITSAT-1. The geo-potential perturbation terms which are seperated inclination terms have been obtained using Algebraic manipulation. Also luni-solar disturbing funtion based on the relative position of the sun, moon, and satellite has been obtained. Phase portraits are used to depict the change of eccentricity and grgument of perigee. The variations of each orbital elements have been obtained in case of the KITSAT-1.