• 어항어장
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• s.78
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• pp.24-28
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• 2007

• Monthly Korean Chicken
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• s.151
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• pp.130-131
• /
• 2008

• KOREAN POULTRY JOURNAL
• /
• v.7 no.9 s.71
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• pp.48-59
• /
• 1975

• The Magazine of the IEIE
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• v.28 no.2
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• pp.79-89
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• 2001

• KIPE Magazine
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• v.4 no.6
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• pp.23-31
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• 1999

• 동위원소뉴스
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• no.10 s.46
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• pp.4-5
• /
• 2000

• KOREAN POULTRY JOURNAL
• /
• v.35 no.2 s.400
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• pp.80-81
• /
• 2003

• Radioisotope journal
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• v.7 no.2
• /
• pp.13-15
• /
• 1992

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.17 no.1 s.104
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• pp.74-80
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• 2006

This paper presents the characteristics of electromagnetic field uniformity in a reverberation chamber that can be used alternatively for the analysis, test and evaluation of electromagnetic interference and immunity. The dual-band diffuser, which can be used at two different frequency bands in a reverberation chamber, is applied, and it is made of two different single-band Schroeder's Quadratic Residue Diffusers. The FDTD method is used to analyze the field characteristics. Compared with single-band diffuser, the dual-band diffuser shows the improvement in not only expansion of test frequency band but also in characteristics of the field uniformity, polarity, power efficiency, and tolerance. Therefore, the reverberation chamber with the dual-band diffuser is a better facility, for the analysis and measurement of electromagnetic interference and immunity, than the reverberation chamber with a single-band diffuser.

• Journal of the Korean earth science society
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• v.30 no.6
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• pp.683-691
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• 2009

Geomagnetic variation around May 2, 2009 when Angdong earthquake broke out was analyzed using the data recorded at the Cheong-yang geomagnetic observatory, KMA. Firstly, we predict the geomagnetic variation by PCA analysis of geomagnetic data, and then compare the predicted value with the observed data to find any significant differences in residuals. Secondly, wavelet semblance technique is applied to compare the time series before and after the earthquake. Some meaningful change is detected in the Z-field. Thirdly, eigen value analysis for the 3 component geomagnetic data is performed. The location of the observatory was too far from the epicenter and the magnitude was too small to find decisive precursory phenomenon. Nevertheless we can detect some significant correlation between the earthquake and the variation of the geomagnetic field. Various signal processing methods applied in this study will give some opportunity to find precursory effects in the future.