• 제목/요약/키워드: Alpha Waves

검색결과 150건 처리시간 0.037초

한반도 남동부에서의 Coda파 감쇠 (Attenuation of Coda Wave in the Southeastern Korea)

  • 김성균
    • 자원환경지질
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    • 제32권4호
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    • pp.379-384
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    • 1999
  • In order to know the characteristics of attenuation of coda wave in the Kyungsang Sedimetary Basin, quality faclity factor for coda wave (coda Q) is estimated from the earthquake data recorded in the KIGAM local seismic network. Thesingle scattering model for coda wave generation is adopted is adopted in estimating coda Q. In the present study, coda Q(Qc)is estimated in the range of $\alpha$=1.5~3.0, where $\alpha$ denotes the normalized time to S-wave travel time and expressed in terms of frequency (f). The deduced function in the range of 1 to 25 Hz is Qc=36.8283$f^{1.15095}$ which represents the strong dependence of coda Q on frequency. It is found that the difference of Qc between U-D, N-S, and E-W components is negligible. This fact suports the back scattering therory that coda wave originates from scattered waves by randomly distributed heterogenities in the crust On the other hand, it is observed that the coda Q increases with increasing epicentral distence. This observation suggests that QC increases with depth.

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1/f-LIKE FREQUENCY FLUCTUATION IN FRONTAL ALPHA WAVE AS AN INDICATOR OF EMOTION

  • Yoshida, Tomoyuki
    • 한국감성과학회:학술대회논문집
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    • 한국감성과학회 2000년도 춘계 학술대회 및 국제 감성공학 심포지움 논문집 Proceeding of the 2000 Spring Conference of KOSES and International Sensibility Ergonomics Symposium
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    • pp.99-103
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    • 2000
  • There are two approaches in the study of emotion in the physiological psychology. The first is to clarify the brain mechanism of emotion, and the second is to evaluate objectively emotions using physiological responses along with our feeling experience. The method presented here belongs to the second one. Our method is based on the "level-crossing point detection" method. which involves the analysis of frequency fluctuations of EEG and is characterized by estimation of emotionality using coefficients of slopes in the log-power spectra of frequency fluctuation in alpha waves on both the left and right frontal lobe. In this paper we introduce a new theory of estimation on an individual's emotional state by using our non-invasive and easy measurement apparatus.

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국민학교 아동의 정서행동문제에 대한 생물 ${\cdot}$ 정신사회학적 연구(II) -뇌파자동해석장치에 의한 주의력 결핍과잉운동장애 아동과 정서행동문제아동의 뇌파조사- (BIO-PSYCHOSOCIAL STUDY OF EMOTIONAL BEHAVIORAL PROBLEMS IN KOREAN ELEMENTARY SCHOOL CHILDREN(II) -Quantitated Various EEG Elements of Basic Activity in ADHD and Emotional Behavioral Problem Children by Computerized Wave Form Recognition Method -)

  • 이정균;장경준;박성호;홍강의
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • 제1권1호
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    • pp.40-54
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    • 1990
  • Rutter의 아동행동평가표에 의한 정서행동문제아동들과 정상아동들 리고 DSM-III-R의 진단기준에 부합되는 주의력결핍과잉운동장애아동들에 대해 뇌파조사를 시행하여 뇌파이상의 빈도와 양상을 알아보았다. 그 결과, 정서행동문제아동군은 정상대조군과 뇌파이상의 빈도 및 양상에 차이를 보이지 않았지만. 주의력결핍과잉운동장애아동군은 정상대조군에 비해 후두부에서 alpha파의 평균 진폭이 낮았고, 평균출현시간이 짧았으며, 또한 좌측 후두부가 우측 후두부에 비해 alpha파 특히 alpha(2)과의 평균출현시간이 길었다. 이로써 국민학교아동의 정서행동문제는 뇌파이상과는 별 관련성이 없는 것으로 판단된다. 하지만 주의력결핍과잉운동장애아동군은 정상 대조군에 비해 alpha파의 발달이 덜 되어 있음을 알았다.

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섬유/플라스틱 사출성형 복합재료의 음향방출 진폭분포에 대한 감쇠효과 (Effects of Wave Attenuation on the Acoustic Emission Amplitude Distribution of Injection-Molded Fiber/Plastic Composites)

  • 최낙삼
    • 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.

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Vitamin $B_1$ (Thiazole 유도체(誘導體))의 정량법(定量法)에 관(關)한 연구(硏究) (Quantitative Determination of Vitamin $B_1$ (Thazole Derivatives))

  • 김용진
    • 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.

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음악치료가 외상 후 스트레스를 받은 청소년의 뇌파 변화 및 정서, 우울, 불안 감소에 미치는 영향 (The Effects of Music Therapy on the Changes in Brain Waves and Emotion, and Reduction of Depression and Anxiety for the Post-traumatic Stressed Adolescent)

  • 최애나;박형준
    • 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.

Excitatory Influences of Noradrenaline on the Spontaneous Contractions and Electrical Activity of Antral Circular Muscle of the Guinea-pig Stomach

  • Lee, Taik-Jong;Kim, Jin-Hwan;Kim, Ki-Whan
    • 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.

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인지적 정신과제 판정을 위한 EEG해석 (EEG Analysis for Cognitive Mental Tasks Decision)

  • 김민수;서희돈
    • 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.

뇌파를 이용한 두개천골요법 기반 베개의 수면유도 효과 검증 (Evaluation of Cranial Sacral Therapy (CST) Based Pillow on Sleep Induction Using the Electroencephalogram (EEG))

  • 권혁찬;표정빈;박용길;이현주;태기식
    • 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.

EEG, fMRI, EAV 및 SQUID장치(裝置)를 이용(利用)한 기공현상(氣功現狀) 측정(測定) (The Studies on Qigong state Using EEG, fMRI, EAV and SQUID Measurments)

  • 정찬원;최찬헌;윤유식;소철호;나창수;장경선
    • 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.

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