• 한국산학기술학회논문지
• /
• 제22권3호
• /
• pp.536-545
• /
• 2021

본 연구는 전기향로를 이용한 침향 흡입이 스트레스와 뇌파에 미치는 영향을 파악하기 위해 시행되었다. 'H' 발달센터 공고로 모집한 성인 남녀 16명 대상으로 2019년도 09월부터 2020년 4월까지 실시하였다. 전기향로에 침향편(沈香片)을 올려놓고 침향 흡입 전과 후의 스트레스 반응과 뇌파 측정을 비교 분석하여 침향 흡입이 스트레스 대처자원의 가능성을 알아보고자 하는 것이다. 뇌파 측정은 19 Channel, Brainmaster Discovery로 하였으며, 분석은 NeuroGuide와 LORETA를 사용하였다. 수집된 자료는 SPSS/WIN 21.0 프로그램으로 기술 통계, Wilcoxon 부호 순위 검정을 하였다. 결과는 첫째, 침향 흡입 후 스트레스 반응 지수는 분노, 우울, 신체화 모든 항목에서 유의수준 0.01로 유의미한 차이로 감소하였다. 둘째, 침향 흡입 후 뇌파에서 측정 부위 19곳 중에서 FP1 1곳을 제외한 18곳에서 Alpha Wave가 증가하였고, 유의수준 0.05에서 확인되었다. 감정에 영향을 주는 영역(우측 측두엽, T6)에서 침향 흡입 전과 후의 차이가 가장 크게 나타났다. 셋째, LORETA 분석 결과 침향 흡입 후 기억과 정서적 활동에 중요한 뇌 영역(BA40)에서 Alpha Wave가 증가하였다. 이러한 결과로 전기향로를 이용한 침향 흡입이 스트레스와 뇌파에 긍정적인 영향을 미쳐 스트레스 대처 자원이 될 가능성을 확인하였다.

• 조명전기설비학회논문지
• /
• 제26권2호
• /
• pp.51-60
• /
• 2012

An improved method for detecting fault distance in overhead transmission lines is described in this paper. Based on single-ended measurement, propagation theory of traveling waves together with the wavelet transform technique is used. In estimating fault location, a simple, but fundamental method using the time difference between the two consecutive peaks of transient signals is considered; however, a new method to enhance measurement sensitivity and its accuracy is sought. The algorithm is developed based on the lattice diagram for traveling waves. Representing both the ground mode and alpha mode of traveling waves, in a lattice diagram, several relationships to enhance recognition rate or estimation accuracy for fault location can be found. For various cases with fault types, fault locations, and fault inception angles, fault resistances are examined using the proposed algorithm on a typical transmission line configuration. As a result, it is shown that the proposed system can be used effectively to detect fault distance.

• 한국세라믹학회지
• /
• 제32권3호
• /
• pp.341-348
• /
• 1995

An analysis of the use of temperature profiles in the determination of the kinetic parameters of combustion synthesis of Ti5Si3 were investigated. From profile analysis, an apparent activation energy of 12KJ/mol was calculated. The Maximum heating rate achieved during 10wt% Ti5Si3 reaction by the product dilution method was approximately $1.5\times$104 K/s. Coupling this value with the measured wave velocity of 7.02 cm/s yields a maximum thermal gradient of 2.14$\times$103 K/cm. The value of tr (=t*) was calculated to be 1.2$\times$10-1 s and the value of td (=tx) was calculated to be 32.89 s. Using the definition of t* and the measured wave velocity, the effective thermal diffusivity, $\alpha$, was calculated to be 0.59$\times$10 $\textrm{cm}^2$/s. From these analysis, the power function, G, was also calculated.

• Korean Journal of Hydrosciences
• /
• 제4권
• /
• pp.81-92
• /
• 1993

This paper presents a model on the migration characteristics which is developed by using the equations for conservation of mass, momentum, and for lateral stability of the streambed. This model enables prediction of the magnitude the location of near-bank bed scour as well as rates and direction of meander migration in the sine-wave type revers (SWR) of small sinuosity. It is evident from this study that the transverse bed slope factor B' and transverse mass flux factor play significant roles in predicting migration characteristics, and their values of B'=4.0 and $\alpha$= 0.4 seem reasonable. This model will produce a useful quidelines in planning, design, construction, and development of SWR basin projects.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2006년도 추계학술대회논문집
• /
• pp.41-47
• /
• 2006

In this study, the influences of environmentally friendly visual and auditory information on traffic noise perception were surveyed by the using electroencephalogram Green rural region image and CBD image in urban city were used as visual informations. And traffic noise, signal and environmental music were used to detect the impact on electroencephalogram variance. It was revealed that green rural region image caused a-wave ratio increase about 10% and environmental music increased $\alpha$-wave ratio approximately $40{\sim}50%$. The results of this study improved that environmentally friendly visual and auditory information had an effect on decreasing traffic noise loudness to some extents.

• 한국섬유공학회:학술대회논문집
• /
• 한국섬유공학회 1998년도 봄 학술발표회 논문집
• /
• pp.291-295
• /
• 1998

The purpose of this Study was to determine thermal sensation and physiological responses for men in winter indoor environment, under various air temperature and relative humidity, with male university students. Subjective Evaluation, Heart Rate Variability(HRV), Electroencephalogram(EEG) were examined. We found that comfort of people was achieved at 50% R.H., 24$^{\circ}C$, and the difference of skin temperature was found at the calf area as air temperature changes. At low air temperature and low humidity, heart rate was decreased, but there was no change at brain wave, keeping ${\alpha}$-wave.

• 대한전기학회논문지:시스템및제어부문D
• /
• 제51권1호
• /
• pp.39-42
• /
• 2002

For the purpose of modeling EEG signal which has nonstationary and nonlinear dynamic characteristics, this paper propose a state feedback real time recurrent neural network model. The state feedback real time recurrent neural network is structured to have memory structure in the state of hidden layers so that it has arbitrary dynamics and ability to deal with time-varying input through its own temporal operation. For the model test, Mackey-Glass time series is used as a nonlinear dynamic system and the model is applied to the prediction of three types of EEG, alpha wave, beta wave and epileptic EEG. Experimental results show that the performance of the proposed model is better than that of other neural network models which are compared in this paper in some view points of the converging speed in learning stage and normalized mean square error for the test data set.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2015년도 제46회 하계학술대회
• /
• pp.1397-1398
• /
• 2015

본 연구에서는 뇌파를 이용하여 자동차에 HUD를 적용하였을 때, HUD의 위치와 이미지 컬러 변경 시 뇌 활성화 지수(Brain Activity Quotient)의 변화를 관찰하였다. 뇌파데이터는 Fp1, Fp2, O1, O2 총 4채널에서 얻었고, HUD위치는 좌측, 중앙, 우측으로 구성하였고 컬러는 초록, 주황, 빨강 총 3가지 색상을 사용하였다. HUD이미지의 크기는 $8{\times}4.5cm^2$로 구성하였다. 뇌 활성화 지수는 상대파워분석(Relative power analysis)를 사용하여 Slow beta wave(13~20 Hz)/alpha wave(4~7.99 Hz)로 계산하였다.

• Journal of Information Display
• /
• 제10권2호
• /
• pp.72-75
• /
• 2009

The Brillouin spectrum of 4'-n-pentyl-4-cyano-biphenyl (5CB) liquid crystals homogeneously confined in a planar liquid crystal (LC) cell was measured using a 6-pass tandem Fabry-Perot interferometer. By adopting a special right-angle scattering geometry, the sound velocity of 5CB was estimated from the Brillouin shift without knowing the refractive index. The sound velocity of the longitudinal wave propagating along the direction of the directors aligned parallel to the glass plates of the LC cell was 1784${\pm}$7 m/s at 300 K. The attenuation coefficient $\alpha$ was estimated to be approximately $1.9{\times}10^6m^{-1}$, which is about twice as large as that of the longitudinal sound wave propagating along the direction perpendicular to the directors. The present method may be very useful in the evaluation of the elastic properties of the materials used in display devices, whose refractive indices are not known.

• 수면정신생리
• /
• 제19권2호
• /
• pp.63-67
• /
• 2012

The reciprocal interaction between sleep and pain has been reported by numerous studies. Patients with acute or chronic pain often complain of difficulty falling asleep, frequent awakenings, shorter sleep duration, unrefreshing sleep, and poor sleep quality in general. According to the majority of the experimental human studies, sleep deprivation may produce hyperalgesic changes. The selective disruption of slow wave sleep has shown this effect more consistently, while results after selective REM sleep deprivation remain unclear. Patients with chronic pain have a marked alteration of sleep structure and continuity, such as frequent sleep-stage shifts, increased nocturnal awakenings, decreased slow wave sleep (SWS), decreased rapid eye movement (REM) sleep, and alpha-delta sleep. Many analgesic medications can alter sleep architecture in a manner similar to the effects of acute and chronic pain, suppressing SWS and REM sleep.