• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1763-1766
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• 2003

Millimeter-wave networking is composed of narrow beam link. it is very substantial that beam connecting point to point is fixed in right direction. It is major requirement in the beam network to keep the beam in best direction. In this paper, We propose the method to find a best suited direction of the antenna's beam using the Genetic Algorithm (GA) in point-to-point link. Proposed method presume that each station knows his direction ${\theta}_1$ , ${\theta}_2$ at every step of GA, then it can be expected that GA is possible to search the ideal solution. Intensity of the received signal is evaluated by the multiplication of lengths to the point which the lobe meets with the horizontal line.

• 동의생리병리학회지
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• 제28권6호
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• pp.674-682
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• 2014

The purpose of this study was to identify the effect of applying oriental music therapy and reliability of electroencephalogram(EEG) equipment. The study was approved by the critical trial judge committee from ${\bigcirc}{\bigcirc}$(IRB No. 2013-07) university. In order to measure test-retest reliability for 15 subjects, EEG for same participants were measured using same method mentioned above after 2 hours from the first measurement. Same provider implemented to each person at same time. Firstly, EEG was measured for 5 minutes after the subject with attached electrodes sat on chair comfortably for 10 minutes. Then, the subject was given mental stress using the four fundamental arithmetic operations for 5 minutes, and measured EEG for another 5 minutes. After that the subject sat on the chair comfortably listening oriental medicine music therapy for 5 minutes, and EEG was measured for 5 minutes again. There was no side effect regarding music therapy reported. Raw data, which was measured in each step, were converted through FFT(fast fourier transform) and analyzed after divided into certain frequency including ${\alpha}$ wave, ${\beta}$ wave, ${\theta}$ wave, immersion wave, stabilization wave, sef100 wave, and sef95 wave. Data were analyzed using wilcoxon signed rank test, Intraclass correlation coefficient(ICC), repeated measures ANOVA with the SPSS program. In test-retes method, there were significantly differences in ${\alpha}$ wave, ${\beta}$ wave, immersion wave, stability wave, ${\theta}$ wave, sef100 wave, sef95 wave. ICC has shown a high degree of reliability that it was ${\alpha}$ wave .877, ${\beta}$ wave .855, ${\gamma}$ wave .895, immersion wave .897, stability wave .816, ${\theta}$ wave .904, sef100 wave .910, sef95 wave .776. Also, there was a statistically significant difference in ${\alpha}$ wave after applying oriental music therapy. Based on these results, it is considered that average of the channel EEG and application of oriental music therapy would be practiced by increase of sample size using this machine.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2016년도 춘계학술대회
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• pp.513-514
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• 2016

최근 뇌파에 대한 연구가 아주 활발하게 진행되고 있다. 이러한 뇌파를 분석하기 위해서는 뇌파센서를 이용하여 뇌파를 수집하고 뇌파의 주파수 분석 등을 이용하여 뇌파를 분석할 수 있다. 이러한 분석을 위하여 본 논문에서는 NeuroSky 사의 mindwave mobile 뇌파 센서를 이용하여 뇌파를 수집하고 수집된 뇌파의 주파수 분석을 이용하여 delta, theta, alpha, SMR, beta 파를 분석하고 이러한 주파수별 뇌파가 집중도와 어떤 상관관계를 갖고 있는지 분석하고자 한다. 이러한 분석을 통하여 일반적으로 알려진 집중도와 beta파의 밀접한 관계뿐만 아니라 다른 주파수 성분과의 상관관계도 분석할 수 있을 것이다. 이러한 기초연구를 통하여 보다 발전된 형태의 뇌파를 연구할 수 있을 것이다.

• 한국전자통신학회논문지
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• 제9권5호
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• pp.589-594
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• 2014

인간은 집중할 때 유발되는 특정한 뇌파가 있는 것으로 알려져 있다. 본 논문에서는 인간의 집중과 관련된 뇌파를 분석하는 것을 목표로 하여, 집중을 유발할 수 있는 도구로 시각자극을 설정하였다. 즉 시각자극으로 구성된 과제를 제시하여 피험자가 집중할 수 있도록 하였다. 피험자로부터 유발되는 뇌파는 전극의 위치에 따른 채널별로 계측하였고, 계측한 뇌파는 주파수대역별로 나누어 분석하였다. 그 중에서도 특히 SMR, Mid-beta, Theta파에 해당되는 주파수대역의 파워 스펙트럼으로 분석하였고, 그 특성을 분석한 결과를 제시하였다.

• 한국산학기술학회논문지
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• 제18권12호
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• pp.459-465
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• 2017

이 연구는 뉴로피드백 훈련이 청소년기 세타파를 감소하는 데 효과가 있는지를 알아볼 목적으로 이루어졌다. 경기도에 거주하는 초기청소년 35명을 대상으로 2016년 4월부터 10월까지 6개월간 청소년상담실에서 이루어졌다. 사전 뇌기능검사에 참여한 대상자 중 참여여건과 의사에 따라 무처지 비교군(A) 10명, 12주훈련집단 실험군(B) 15명, 24주훈련집단 실험군(C) 10명으로 분류하여 설계하였다. 뇌파측정 및 뉴로피드백 훈련은 (주)파낙토스의 전전두엽 2채널 뉴로하모니S와 두뇌최적화 소프트웨어로 수행하였으며 뇌파데이터 처리는 (재)한국정신과학연구소에서 개발한 Brain Analysis ver 1.3을 사용하였다. 이렇게 도출한 데이터는 통계처리가 가능하도록 SPSS 21.0으로 변환하였다. 청소년들의 세타파 감소 훈련을 위해 개별적으로 훈련 프로토콜을 정해주었으며 베타파 증가훈련을 통해 세타파를 감소하는 전략으로서 개인에게 알맞은 알파파, SMR, 저베타파 증가 훈련을 적용하였다. 그 결과 전전두엽 뉴로피드백 훈련을 통해 청소년들의 세타파 감소가 감소하는 것으로 확인되었고, 훈련을 받은 집단(B)(C)에서, 또 훈련의 기간이 좀더 긴 집단(C)에서 세타파 감소의 폭이 큰 것으로 확인되었다.

• 한국안광학회지
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• 제7권1호
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• pp.51-55
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• 2002

본 연구는 정상 시력을 가진 피검자의 안구가 동향운동을 하도록 주시점의 위치를 변경하며, 동향운동이 대뇌 시 피질 cerebral visual cortex의 뇌파에 미치는 영향을 분석하였다. 시 유발전위 장치(visual evoked potential system)는 Bio-Pag(production in USA)을 이용하였으며, 검사결과는 컴퓨터에 입력하여 분석하였다. 검사실의 조도는 50lux이며, 사용한 시표의 직경은 3 cm의 붉은 광점이며, 우전 dextroversion과 좌전 levoversion에 따른 결과는 다음과 같다. 1. 시자극에 관계하는 시 피질의 뇌파 출현의 높은 빈도는 delta wave, beta wave, theta wave 그리고 alpha wave의 순으로 나타났다. 2. 우전과 좌전에 대한 뇌파의 종류와 진폭은 거의 비슷하다. 3. 진폭에 대한 히스토그램은 우전과 좌전 모두 가우시안 Gausian 분포로 나타났다. 4. 뇌파의 진폭에 대한 위상 분석의 결과는 거의 비슷하다. 5. 뇌파 진폭과 주파수에 대한 fast fourier transform 분석에서 대개 20 Hz 이하의 저주파 low frequency로 나타났으며, 우전과 좌전의 결과는 비슷하다.

• 대한물리치료과학회지
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• 제15권3호
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• pp.9-17
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• 2008

Background : The conventional electroencephalography(EEG) is commonly used as aid in the diagnosis of dementia. Recently developed quantitative electroencephalography(qEEG) provides data that are not achievable by conventional EEG. The aim of this study was to find out the usefulness of quantified-EEG in dementia. Method : Twenty elderly women(10 normal elderly, 10 demented elderly) were participated in this study. EEG power and coherence was computed over 21 channels; right and left frontal, central, parietal, temporal and occipital areas. Result : The activity of ${\alpha}$ wave was more higher than others significantly at frontal and parietal areas in normal elderly, but the activity of ${\theta}$ wave was higher in demented elderly. And the activity of ${\theta}$ wave in demented elderly women was more higher than normal elderly women significantly. Conclusion : In conclusion, we discovered that quantitative EEG was used to diagnose dementia.

• Bulletin of the Korean Chemical Society
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• 제21권12호
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• pp.1227-1232
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• 2000

Near the conical intersection for the 1,2 $^{2}A'$ states of $H_3$ the derivative coupling vector is calculated and analyzed on the plane of internal coordinates, (U,V) or its polar coordinates $(S{\theta})$, based on the squares of the internuclear distances. It is shown that in the vicinity of the conical intersection the derivative coupling vector behaves like ${\theta}/2S$, which is responsible for the sign changes of the real-valued electronic wave function when the nuclear configuration traverses a closed path enclosing a conical intersection. The analytic property of the wave functions is studied and especially the observation of the sign change in the configuration state function (CSF) coefficients of the real-valued electronic wave functions is demonstrated.

• Current Optics and Photonics
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• 제3권4호
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• pp.342-349
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• 2019

We present a theoretical research concerning terahertz (THz) wave generation with $KTiOPO_4$ (KTP) by collinear phase matching (CPM) stimulated polariton scattering (SPS). Both CPM and corresponding nonzero nonlinear coefficients can be simultaneously realized with $s{\rightarrow}f+f$ in yz plane, $s{\rightarrow}f+s$ with ${\theta}$ < ${\Omega}$ in xz plane and $s{\rightarrow}f+f$ with ${\theta}$ < ${\Omega}$ in xz plane. The effective nonlinear coefficients including electronic nonlinearities and ionic nonlinearities are calculated. Based on the parameter values of refractive indices, absorption coefficients and effective nonlinear coefficients, we simulate THz wave intensities generated with CPM SPS by solving coupled wave equations and give the relationship among the maximum THz wave intensity, optimal crystal length and the angle ${\theta}$. The calculation results demonstrate that CPM SPS with KTP can generate THz waves with high intensities and quantum conversion efficiencies.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1997년도 추계학술발표회논문집(1)
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• pp.481-486
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• 1997

The interfacial shear stress is experimentally investigated for co-current air-water stratified flow in inclined rectangular channels having a length of 1854mm, width of 120mm and height of 40mm at almost atmospheric pressure. Experiments are carried out in several inclinations from $0^{\circ}\;up\;to\;10^{\circ}$. The local film thickness and the wave height are measured at three locations, i.e., L/H = 8,23, and 40. According to the inclination angle, the experimental data are categorized into two groups; nearly horizontal data group ($0^{\circ}\;{\leq}\;{\theta}\;{\leq}\;0.7^{\circ}$), and inclined channel data group ($0.7^{\circ}\;{\leq}\;{\theta}\;{\leq}\;10^{\circ}$). Experimental observations for nearly horizontal data group show that the flow is not fully developed due to the water level gradient and the hydraulic jump within the channel. For the inclined channel data group, a dimensionless wave height, $\Delta$h/h, is empirically correlated in terms of $Re_{G}$ and h/H. A modified root-mean-square wave height is proposed to consider the effects of the interfacial and wave propagation velocities. It is found that an equivalent roughness has a linear relationship with the modified root-mean-square wave height and its relationship is independent of the inclination.