• 대한의용생체공학회:의공학회지
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• 제8권1호
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• pp.69-74
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• 1987

The power spectrum of background EEG is estimated by the Plsarenko Harmonic Decomposition with the stochastic process whlch consists of the nonhamonic sinus Bid and the white nosie. The estimation results are examined and compared with the results from the maximum entropy spectral extimation, and the optimal order of this from the maximum entropy spectral extimation, and the optimal order of this model can be determined from the eigen value's fluctuation of autocorrelation of background EEG. From the comparing results, this method is possible to estimate the power spectrum of background EEG.

• 한국전자통신학회논문지
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• 제9권12호
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• pp.1421-1426
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• 2014

현대의 복잡한 도시생활로 인하여 많은 이들이 크고 작은 정신적인 스트레스를 호소하고 있으며 이에 따라 각종 정신질환에 노출되어 있다. 특히, 학생이나 직장인 할 것 없이 많은 이들이 집중력 부족으로 인하여 일의 능률 저하나 양질의 생활 유지에 어려움을 가지고 있다. 이러한 집중력을 향상시키기 위해 명상이 대안으로 떠오르고 있으며, 이러한 명상이 집중력에 어떠한 형태로 영향을 미치는지 알아보기 위해 EEG 뇌파를 활용하여 실험하였다. 명상경험자를 실험대상으로 하였으며 뇌의 좌우반구의 전전두엽 영역에 배치된 AF3와 AF4영역을 중점적으로 관찰하고 분석하였다. 그 결과 리듬성 활동 뇌파의 특유한 패턴과 파워 스팩트럼의 변화를 관찰할 수 있었다.

• 대한기계학회논문집B
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• 제20권3호
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• pp.1028-1039
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• 1996

This study was focused on the examination of the flame structure and the combustion characteristics of diffusion flame which was formed the turbulent shear flow of a double coaxial air jet system. The shear flow was formed by the difference velocity of surrounding air jet(U$\_$s/) and center air jet (U$\_$c/). So experimental condition was divided S-type flame (.lambda. > 1) and C-type flame (.lambda. < 1) by velocity ratio .lambda. (=U$\_$s//U$\_$c/). For examination of the flame structure and the combustion characteristics in diffusion flame, coherent structure was observed in flame by schlieren photograph method. We measured fluctuating temperature and ion current simultaneously and accomplished the statistical analysis of its. According to schlieren photograph, the flame was stabilized in the rim of the direction of lower velocity air jet, coherent eddy was produced and developed by higher velocity air jet. The statistical data of fluctuating temperature and ion current was indicated that reaction was dominated by higher velocity air jet. The mixing state of burnt gas and non-burnt gas was distributed the wide area at Z = 100 mm of C-type flame.