• The Bulletin of The Korean Astronomical Society
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• v.31 no.1
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• pp.19.2-19.2
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• 2006

• Journal of the Korean Society for Aviation and Aeronautics
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• v.20 no.2
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• pp.13-17
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• 2012

The solar storm generated by solar activity can be impact on earth in various area. If solar storm impact on Navaids system, it will be a serious problem for aviation and human safety. The impact analysis of solar strom on Navaids system are performed in three area, ILS, GPS navigation and radio communication for aviation. Analysis result show that Instrument Landing System(LLZ, GP, MB) and Navaids system(VOR, DME, Radar) are not impacted by the solar storm, but GPS system is impacted by solar storm. Also analysis result show that VHF/UHF radio system are not impacted by solar storm, but HF radio system is impacted by solar storm.

• Current Photovoltaic Research
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• v.1 no.1
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• pp.11-16
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• 2013

The current solar cell industry is experiencing a temporary plateau due to a sluggish economy and oversupply. It is expected that the solar industry can see similar growth to that of the recent past by overcoming the current situation, as there is growing demand globally for solar energy. The current situation led to restructuring of the world's solar industry, and domestic firms will need to have competitiveness through strategic approaches and proprietary technology to survive in the global solar market. Crystalline and amorphous silicon based solar cells have led the solar industry and occupied half or more of the market thus far. They will do so in the future PV market as well by playing a pivotal role in the solar industry. In this paper, the current status and prospects of silicon based solar cells, from materials to comprehensive and high efficiency technology that can emerge in the future, are discussed.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.43.2-43.2
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• 2011

Minority Carrier recombination should be suppressed for high efficiency solar cells. However, impurities in the silicon bulk region deteriorate the minority carrier lifetimes, causes conversion efficiency drop. In this study, we introduced phosphorus external gettering for silicon heterojunction solar cell substrates. Gettering was undergone at 750, 800, 850 and $900^{\circ}C$ in furnace for 30 minutes. Bulk lifetimes and calculated diffusion length were improved. We applied phosphorus gettering to silicon heterojunction solar cells. Gettered group and ungettered group were used as substrate of silicon heterojunction solar cells. After fabrication, characteristics of solar cells were analyzed. The results were observed to see the enhancement of substrate quality which directly connects with solar cell properties.

• The Bulletin of The Korean Astronomical Society
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• v.32 no.1
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• pp.24.2-24.2
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• 2007

• The Bulletin of The Korean Astronomical Society
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• v.38 no.2
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• pp.96.2-96.2
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• 2013

The solar images are taken by the CCD detectors of the Sun monitoring satellites. The solar images are constructed after removing the traces of cosmic rays on the raw CCD data files. Thus, while applying the method of removing the cosmic rays traces, we can estimate the cosmic rays flux by counting the number of traces. The cosmic ray flux in the steady state might be the sum of the solar and galactic cosmic rays. However, the abrupt change in the flux could be assumed to be originated from the Sun. Therefore, we can identify the solar origins of the sudden solar cosmic ray flux changes from the phenomena shown in the processed solar images taken by SOHO/EIT. As the results, the estimated cosmic ray flux in the steady state is the anti-correlated with sunspot numbers, which shows the minima in cosmic ray flux at the solar cycle maxima defined by the sunspot numbers. The profiles of estimated solar cosmic ray associated with the ground level enhancements have the significant increase in the cosmic ray flux with good correlation. Thus, the solar images are valuable data useful in estimating the solar cosmic ray long term and transient flux variations.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.11
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• pp.699-704
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• 2017

The amount of electric power for photovoltaic power generation depends on the location of the power plant and the direction of solar cell. The solar cell controls the generation of solar power plants. Therefore, the structure of solar cell, manufacturing method, and optic technology were factors contributing to increased solar cell efficiency; however, the technical limit has been reached. Herein, we propose a new method to increase the solar cell efficiency using a wavelength conversion technology that converts ultraviolet and infrared rays, which are not effectively used in solar cells, into effective wavelength of solar cell. We used fluoride $Na(Ca)YF_4$ phosphor for wavelength conversion. Then, a wavelength-conversion fluorescent paste, prepared using an organic-silicon binder, was used to prepare a film that was applied to Si solar cells. It was confirmed that conversion efficiency improved by 5% or more.

• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.168-171
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• 2006

The Korean Solar Thermal Industry hopes to realize 1 Million Solar Thermal Roofs. According to the 2nd Renewable Basic Plan : 2003-2012 the Government showed a very aggressive Solar Thermal Deployment Plan including Solar Thermal Apartment Housings Program. Owing to the Vision Statement such as Million Solar Thermal Roofs Program Korean Solar thermal Industry also can bring another shinny days Especially the more solar thermal applications such as to the Apartment Housings and Green Villages could bring a sustainable Solar Society Korea The RPA Program by the 9 Major Non-Private Energy Corporal ions and the RPS Program for the Solar Thermal Energy shall be another useful policy for the realization of Million Solar Korea era.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.1
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• pp.39-48
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• 2013

The solar radiation is the primary energy source that drives many of the earth's physical and biological processes and climate change. Understanding its importance to the solar radiation observation is a key to understanding a broad range of natural processes, agricultural, energy and human activities. The purpose of this study is to estimate solar radiation using sunshine duration, and to estimate distribution of solar radiation using a topography factor considering surface slope and aspect in complex terrain. The result of regression analysis between ratio of solar radiation and sunshine duration from 2001 to 2010 shows high $R^2$ value of 0.878. Regression analyses indicated that topographic attributes including elevation, slope and aspect had significant effects on solar radiation. The variation of topographic factor with aspect and slope for the summer and winter are considered. The highest month of daily mean solar radiation at Jeju island appears in April of 20.61 $MJ{\cdot}m^{-2}{\cdot}day^{-1}$, and the lowest month appears in December of 6.90 $MJ{\cdot}m^{-2}{\cdot}day^{-1}$. These results provided useful quantitative information about the influence of topography on solar radiation in the island region.

• Journal of Astronomy and Space Sciences
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• v.27 no.4
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• pp.319-327
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• 2010

We examine the ionospheric F2-layer electron density variation by solar activity in middle latitude by using foF2 observed at the Kokubunji ionosonde station in Japan for the period from 1997 to 2008. The semi-annual variation of foF2 shows obviously in high solar activity (2000-2002) than low solar activity (2006-2008). It seems that variation of geomagnetic activity by solar activity influences on the semi-annual variation of the ionospheric F2-layer electron density. According to the Lomb-Scargle periodogram analysis of foF2 and Ap index, interplanetary magnetic field (IMF) Bs (IMF Bz <0) component, solar wind speed, solar wind number density and flow pressure which influence the geomagnetic activity, we examine how the geomagnetic activity affects the ionospheric F2-layer electron density variation. We find that the semi-annual variation of daily foF2, Ap index and IMF Bs appear clearly during the high solar activity. It suggests that the semi-annual variation of geomagnetic activity, caused by Russell-McPherron effect, contributes greatly to the ionospheric F2-layer semi-annual electron density variation, except dynamical effects in the thermosphere.