• 천문학논총
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• 제30권2호
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• pp.57-58
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• 2015

In this study, we present geometrical and kinematical analysis of Moreton wave observed in 2012 June 3rd and July 6th, recorded in H-${\alpha}$ images of Global Oscillation Network Group (GONG) archive. These large-scale waves exhibit different features compared to each other. The observed wave of June 3rd has angular span of about $70^{\circ}$ with a diffuse wave front associated to NOAA active region 11496. It was found that the propagating speed of the wave at 17:53 UT is about $931{\pm}80km/s$. The broadness nature of this Moreton wave can be interpreted as the vertical extension of the wave over the chromosphere. On the other hand, the wave of July 6th associated with X1.1 class are that occurred at 23:01 UT in AR NOAA11515. From the kinematical analysis, the wave propagated with the initial velocity of about $994{\pm}70km/s$ which is in agreement with the speed of coronal shock derived from type II radio burst, v ~ 1100 km/s. These two identified waves add the inventory of the large-scale waves observed in 24th Solar Cycle.

• 한국전자통신학회논문지
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• 제15권3호
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• pp.527-532
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• 2020

본 논문에서는 개인인증 시 활용 가능한 EEG 신호의 주파수 대역을 확인하기 위하여 뇌파 측정을 통해 분석한 결과를 제시하였다. 시각 과제의 유무에 따라 개안 상태와 폐안 상태로 구분하여 뇌파를 측정하였으며, 이를 델타파, 세타파, 알파파, SMR파, 중간베타파, 베타파 및 감마파의 7종류의 주파수 대역으로 나누어 시간에 따른 파워의 변동이 가장 작은 주파수 대역을 관찰하였다. 본 논문의 결과에서는 개안 상태와 폐안 상태에서는 유의한 차이가 나타나지 않았으나, 인간의 집중과 관련한 SMR파 및 중간베타파가 시간에 따른 파워의 변동이 가장 작게 관찰되었기에 재현성이 높은 주파수 대역인 것으로 나타났다.

• International Journal of Advanced Culture Technology
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• 제10권4호
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• pp.286-293
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• 2022

In this study, we extracted sound waves that can improve psychological skills for volleyball players, investigated the changes that the application training of the extracted sound waves has on the brain waves of volleyball players, and the changes in brain waves are the psychological of volleyball players. The purpose of the research is to investigate the effect on technology. In order to achieve this purpose of the study, a total of 10 people from the experimental group and 10 from the control group were selected as the research subjects of university volleyball players with more than 5 years of volleyball experience. The experimental procedure was for the experimental group to listen to sound waves for more than 30 minutes at least 4 times a week for 12 weeks, and brain waves were measured 3 times before, during, and after. In addition, psychological skills were measured twice before and after. The measured data were subjected to t-test and two-way variance repeated measures analysis using SPSS 20.0. The results obtained through this process are as follows. First, as a result of analyzing the differences in psychological skills according to sound wave application training, there were statistically significant differences in goal setting and attention factors of the experimental group. Second, as a result of repeated measurement variance analysis at each time point according to the application of the sound wave application training program, it was found that alpha waves had a synergistic effect at the statistical significance level in the experimental group. Third, as a result of repeated measurement variance analysis at each time point according to the application of the sound wave application training program, it was found that the beta wave had a synergistic effect at the statistical significance level in the experimental group.

• 비파괴검사학회지
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• 제18권1호
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• pp.1-9
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• 1998

짧은 섬유로 강화된 열가소성수지의 복합재료를 대상 재료로 하여 AE의 발생위치(AE source location)를 구하고 AE신호의 진폭분포에 미치는 감쇠 손실(attenuation loss)의 영향을 정량적으로 검토했다. 모의 AE파를 이용하여 측정된 감쇠율은 시험편내의 섬유체적함유율의 증가에 따라 단순 선형관계식으로 예상되는 값보다 더 작았다. 시험편에서 계측된 AE진폭분포에 감쇠손실을 보정한 결과, 시험편의 게이지부에 설정된 각 구역에서 서로 유사한 수준의 진폭분포가 나타났다. 또한 보정된 AE진폭은 시험편의 변형이 진행됨에 따라 더욱 크게 되었다. 따라서, AE진폭을 이용한 고분자복합재료의 손상해석에서는 AE파의 감쇠효과를 보정해야 됨이 확인되었다.

• 한국식품과학회지
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• 제12권1호
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• pp.41-44
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• 1980

Vitamin $B_1$의 모형(模型) 화합물(化合物)인 3-benzyl-4-methylthiazolium bromide, (1), 3, 4-dimethylthiazolium iodide (2) and 2-($\alpha$-hydroxyethyl)-3-benzyl-4-methylthiazolium bromide (3)을 유기(有機) 화학적(化學的) 합성법(合成法)으로 제조(製造)하였다. Thiazole 유도체(誘導體)는 phosphotungstic acid로 발색(發色)시켜 하룻밤 방치(放置) 후(後)의 흡광도(吸光度)가 발색(發色) 즉시(卽時)의 흡광도(吸光度)에 비(比)하여 화합물(化合物)(1)은 $1.1{\sim}1.2$배(倍) 화합물(化合物)(3)은 $1.5{\sim}1.9$배(倍)가 증가(增加)하였다. 2.6-dibromoquinone chloroimide 비색(比色) 정양법(定量法)은 화합물(化合物)(1)이 화합물(化合物)(3)에 비(比)하여 $2.2{\sim}2.5$배나 늘었다. 화합물(化合物)(1), (2), (3)의 산화파(酸化波) 그리고 환원파(還元波)의 half wave potential과 확산(擴散) 전류(電流)는 모두 그 값이 다르다. 이 연구(硏究)의 결과(結果)로 볼 때 이 모형(模型) 화합물(化合物)(1), (2), (3)의 정량가(定量價)를 그대로 Vitamin $B_1$에 응용(應用)할 수 없음이 판명(判明)되었다.

• 가정과삶의질연구
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• 제26권4호
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• pp.13-25
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• 2008

This study of a music therapy program for the 18 subjects residing in Jeollanam-do province was conducted two times per week during 4 months totalling 17 times in order to evaluate the reduction of the characteristics of patients suffering from stress disorder patients such as depression, and anxiety, Though the experiment for non-symmetric level the concentration and appearance of Alpha wave were determine to be stable but the findings from non-symmetric level according to the left-right brain activity were not significant for T-test, though its effective intermission of music therapy due to variation of the mean values was demonstrated, and the variation of the Alpha wave appearance rate was also significant for the statistics of the T-test for the effectiveness of the music therapy. And for the reduction of depression, emotion, and state-trait anxiety between groups divided into the control group and the experiment, pre-measurement and post-measurement comparisons through psychological tess, validated the effectiveness of music therapy for Posttraumatic stress disorder patients. First of all, this study was conducted in the situation of scarce study cases and program developments for the efficacy of music therapy for the patients suffering from Posttraumatic stress disorders without precedent studies of scientific identification through brain wave measurement. Because this study is insightful in the context of validating the efficacy of musical treatment, we expect that these kinds of studises will be continued.

• The Korean Journal of Physiology
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• 제25권2호
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• pp.147-158
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• 1991

The effects of noradrenaline on the spontaneous contraction recorded from a strip of mucosa-free antral circular muscle were studied in the guinea-pig stomach, and the changes in slow waves and membrane resistance were analyzed in order to elucidate the mechanism for the excitatory response to noradrenaline. Electrical responses of circular muscle cells were recorded using glass microelectrodes filled with 3 M KCI. Electrotonic potentials were produced to estimate membrane resistance by the partition stimulating method. All experiments were performed in tris-buffered Tyrode solution which was aerated with 100% $O_2$ and kept at $35^{\circ}C$. The results obtained were as follows: 1) The spontaneous contractions were potentiated dose-dependently by the application of noradrenaline. 2) Through the experiments using adrenoceptor-blockers, the strong excitatory effect via $[\alpha}-adrenoceptors$ and the weak inhibitory efffect via ${\beta}-adrenoceptors$ were noted. 3) Noradrenaline produced hyperpolarization of membrane potential, and increases in the amplitude and the maximum rate of rise of slow waves. 4) In the presence of apamin, Ca-dependent K channel blocker, the characteristic hyperpolarization was not developed. However, the excitatory effect of noradrenaline on spontaneous contraction remained. 5) Membrane resistance was reduced during the hyperpolarized state by the application of noradrenaline, and the change of membrane resistance and the hyperpolarized state were completely abolished by apamin. From the above results, following conclusions could be made: Excitatory responses to noradrenaline result from the dominant ${\alpha}-excitatory$, and the weak ${\beta}-inhibitory$ action of noradrenaline. Hyperpolarization of membrane potential by noradrenaline is due to the activation of Ca-dependent K channel.

• 센서학회지
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• 제12권6호
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• pp.289-297
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• 2003

본 논문에서는 정신적 과제수행 동안 EEG 뇌파의 정확한 분류방법에 관하여 기술한다. 피험자는 실험 task에서 시각적 자극에 대한 반응, 문제의 해석, 손동작 제어와 키 선택을 수행한다. 선택시간을 감지하기 위하여 측정한 뇌파로부터 $\alpha$, $\beta$, $\theta$, $\gamma$를 분리하고 4가지의 특징들을 해석한파. 이 특징들을 분석하여 각 피험자별로 공통적인 특징플로 구성된 일반 규칙을 설정한다. 본 시스템의 신경망은 1개의 은닉층을 갖는 3층의 피드포워드 신경망 구조를 가지며 학습에는 역전파 학습 알고리즘을 이용하였다. 4명의 피험자를 대상으로 설정한 알고리즘들을 적용하여 평균 87% 분류 성공률을 보였다. 본 논문에서 제안한 방법은 인지적인 정신과제 판별을 위한 방법들과 결합하여 BCI 기술을 위한 기반 기술로 활용될 수 있다.

• 대한의용생체공학회:의공학회지
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• 제39권1호
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• pp.55-61
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• 2018

The purpose of this study was to investigate the effect of a pillow simulated with cranial sacral therapy (CST) on sleep induction using electroencephalography (EEG). This study included 12 voluntary participants divided into experimental group (CST group) and control group (Non-CST group) to observe EEG changes. The position of the electrode for EEG measurement consists of 8 channels electrodes (Fp1, Fp2, F3, F4, T3, T4, P3 and P4). In this study, we measured the fall asleep time, change of brain activity and sleep wave ratio using EEG wave (${\delta}$, ${\theta}$, ${\alpha}$, ${\beta}$ and ${\gamma}$). As a result, the mean fall asleep time of the experimental group was shorter than that of the control group significantly (p < 0.001). Also in comparison with the control group, both the delta (d) and theta (q) wave corresponding to the slow waves showed a larger increase and the alpha (a) wave showed a larger decrease significantly. The slow waves of experimental group showed a higher rate of significant increase than the control group (p < 0.001). Therefore this study showed that pillow based on CST had an effective in improving sleep induction and quality.

• Korean Journal of Acupuncture
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• 제21권2호
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• pp.1-28
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• 2004

Objectives : Human physiological changes in the state of qigong has been measured using EEG(Electroencephalography), functional MRI(functional Magnetic Resonance Image), EAV(Electro-Acupuncture according to Voll) and SQUID(Superconducting Quantum Interference Device) measurements. Methods & Results : EEGs were measured to study the differences between Qigong masters and Qi receiver on the changes of EEG. During Qigong, an alpha waves were increased. The power spectra indicate that the peak frequency of alpha waves increased during Qigong. Qi receiver's EEG signals seemed to affected by the state of himself. Brain activation did not observed when qigong master concentrates the Qi at Laogong(P8). But a localization of fMRI signal in the sensory cortex was observed by electric acupuncture stimulation at Laogong(P8). Five phase deviation of EAV were clearly changed in the both cases of Qigong master and Qi receiver. When a Qigong master concentrates the Qi at Yintang, Laogong(P8), Qihai(CV6) meridian points during Qigong state, the change of magnetic field around acupoints Yintang, Laogong points has been measured using 40-Channel DROS-SQUID apparatus. After smoothing process of the continuously measured magnetic signal around acupoints for a few minutes, we could observe that a series of peaks, magnitude of -1.0~2.5pT appeared. But there was no significant difference in changes of magnetic signal around acupoints. Physical signals of magnetocardiogram has been measured by using 2-Channel DROS SQUID(Magnetocardiogram). Physical signals of magnetocardiogram were clealy changed at the ST segments after S-wave when qigong master concentrates the Qi.