• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2000.04a
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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.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.2
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• pp.51-60
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• 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.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.459-465
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• 2017

This research aims to assess whether neurofeedback training can reduce theta waves in adolescents. The experiment was conducted on 35 early youths living in Gyeonggi-do at youth counseling centers during April-October. According to circumstances and opinions of participants in the pre-brain analysis, they were classified into a non-training group (A), 12-week training group (B), and 24-week training group (C), containing 10, 15, and 10 members, respectively. EEG measurement and neurofeedback training was performed using the prefrontal 2-channel NeuroharmonyS and Brain Optimization program. EEG data was processed utilizing Brain Analysis ver1.3. Deducted data was converted to SPSS 21.0 to enable statistical processing. As a strategy to reduce theta through the Beta increase training, we applied the appropriate Alpha, SMR, Beta low reward training to the individual. Study results confirmed that theta waves of adolescents decreased through the prefrontal neurofeedback training. Groups (B) and (C) exhibited a greater decrease in theta waves compared with the control group.

• Korean Journal of Occupational Health Nursing
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• v.29 no.2
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• pp.114-122
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• 2020

Purpose: This study aimed to identify the effect of integrated nursing using cognicise and neurofeedback on cognition and α waves among elderly individuals. Methods: This quasi-experimental single group pretest-posttest study included 29 Korean adults aged 65 years or older who participated at a senior welfare center in Y city from February to May 2019. Each integrated nursing session consisted of cognicise (10 minutes) and neurofeedback (20 minutes). Subjects participated twice a week for 10 weeks. Structured questionnaires to assess participants' general characteristics and the Korean version of the Mini-Mental Status Examination for Dementia Screening (K-MMSE-DS) were applied. Alpha waves were measured using BrainMaster. Results: Following the integrated nursing program, alpha waves improved in F3 (t=2.41, p=.023), C3 (t=3.00, p=.006), C4 (t=2.60, p=.015), P3 (t=2.43, p=.022), O1 (t=2.30, p=.029), T3 (t=3.05, p=.005), T4 (t=2.28, p=.030), T5 (t=2.91, p=.007), Fz (t=2.30, p=.029), Cz (t=2.73, p=.011), and Pz (t=2.23, p=.034). Most subjects experienced improvement in concentration after participating in the intervention. Conclusion: This study provides evidence for the use of a neuroscientific approach including brain wave measurement to improve cognitive health among community-living elderly people.

• Journal of The Korean Society of Integrative Medicine
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• v.7 no.3
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• pp.171-180
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• 2019

Purpose : The purpose of this study was to investigate the difference in motor cortical excitability during mental practice and action observation in subjects with forward head posture. Methods : This study was performed in two groups, a forward head posture group (n=17) and a normal posture group (n=17). Electroencephalography (EEG) was conducted to investigate cerebral cortex activity, and six electrodes were attached to Fp1, Fp2, C1, C2, C3, and C4 to measure the relative alpha power, relative beta power, relative gamma power, and mu rhythms. The subjects were requested to perform the four different conditions, which were eye opening, eye closing, mental practice, and action observation for 300 seconds. Results : The results showed that the relative alpha waves showed a significant difference between the normal and forward head posture groups in the C1, C2, C3, and C4 regions with the eyes open (p<.05). The relative beta waves also showed a significant difference between the two groups in the Fp1 and Fp2 regions during action observation (p<.05). The relative gamma waves were significantly different between the normal and forward head posture groups in the Fp1 and Fp2 regions during action observation (p<.05) in C1, C2, and C3 with eyes closed (p<.05) and in C1, C2, C3, and C4 with eyes open (p<.05). Conclusion : The results of this study showed that EEG change in the forward head posture group was different from that in the normal control group in action observation rather than in mental practice. Therefore, we are expected to provide a neurophysiological basis for applying action observation to motor skill learning during exercise for correcting forward head posture.

• Korean Journal of Biological Psychiatry
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• v.21 no.4
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• pp.168-174
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• 2014

Objectives Sensory gating dysfunctions in patients with schizophrenia and bipolar disorder have been investigated through two similar methods ; P50 suppression and prepulse inhibition paradigms. However, recent studies have demonstrated that the two measures are not correlated but rather constitute as distinct neural processes. Recent studies adopting spectral frequency analysis suggest that P50 suppression reflects the interaction between gamma and other frequency bands. The aim of the present study is to investigate which frequency component shows more significant interaction with gamma band. Methods A total of 108 mood disorder patients and 36 normal subjects were included in the study. The P50 responses to conditioning and test stimuli with an intra-pair interval of 500 msec were measured in the study population. According to P50 ratio (amplitude to the test stimulus/amplitude to the conditioning stimulus), the subjects with P50 ratio less than 0.2 were defined as suppressed group (SG) ; non-suppressed group (NSG) consisted of P50 ratio more than 0.8. Thirty-five and 25 subjects were included in SG and NSG, respectively. Point-to-point correlation coefficients (PPCCs) of both groups were calculated between two time-windows : the first window (S1) was defined as the time-window of one hundred millisecond after the conditioning auditory stimulus and the second window (S2) was defined as the time-window of 100 msec after the test auditory stimulus. Spectral frequency analysis was performed to investigate which frequency band results in the difference of PPCC between SG and NSG. Results Significant reduction of PPCC between S1 and S2 was observed in the SG (Pearson's r = 0.24), compared to PPCC of the NSG (r = 0.58, p < 0.05). In spectral frequency analysis, gamma band showed "phase-reset" and similar responses after the two auditory stimuli in suppressed and non-suppressed group. However in the case of alpha band, comparison showed significantly low PPCC in SG (r = -0.14) compared to NSG (r = 0.36, p < 0.05). This may be reflecting "phase-out" of alpha band against gamma band at approximately 50 msecs after the test stimulus in the SG. Conclusions Our study suggests that normal P50 suppression is caused by phase-out of alpha band against gamma band after the second auditory stimulus. Thus it is demonstrated that normal sensory gating process is constituted with attenuated alpha power, superimposed on consistent gamma response. Implications of preserved gamma and decreased alpha band in sensory gating function are discussed.

• Journal of The Korean Association For Science Education
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• v.21 no.3
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• pp.516-528
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• 2001

In the educational study, the measure of EEG(brain waves) can be useful method to study the functioning state of brain during learning behaviour. This study investigated the changes of neuronal response according to four times repetition of audio-visual learning. EEG data at the prefrontal$(Fp_{1},Fp_{2})$ were obtained from twenty subjects at the 8th grade, and analysed quantitatively using FFT(fast Fourier transform) program. The results were as follows: 1) In the first audio-visual learning, the activities of $\beta_{2}(20-30Hz)$ and $\beta_{1}(14-19Hz)$ waves increased highly, but the activities of $\theta(4-7Hz)$ and $\alpha$ (8-13Hz) waves decreased compared with the base lines. 2). According to the repetitive audio-visual learning, the activities of $\beta_{2}$ and $\beta_{1}$ waves decreased gradually after the 1st repetitive learning. And, the activity of $\beta_{2}$ wave had the higher change than that of $\beta_{1}$ wave. 3). The activity of $\alpha$ wave decreased smoothly according to the repetitive audio-visual learning, and the activity of $\theta$ wave decreased radically after twice repetitive learning. 4). $\beta$ and $\theta$ waves together showed high activities in the 2nd audio-visual learning(once repetition), and the learning achievement increased highly after the 2nd learning. 5). The right prefrontal$(Fp_{2})$ showed higher activation than the left$(Fp_{1})$ in the first audio-visual learning. However, there were not significant differences between the right and the left prefrontal EEG activities in the repetitive audio-visual learning. Based on these findings, we can conclude that the habituation of neuronal response shows up in the repetitive audio-visual learning and brain hemisphericity can be changed by learning experiences. In addition, it is suggested once repetition of audio-visual learning be effective on the improvement of the learning achievement and on the activation of the brain function.

• The Korean Journal of Physiology
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• v.23 no.2
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• pp.277-289
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• 1989

The effects of noradrenaline on the contractile and electrical activities were investigated using the circular muscle strips with intact mucosa prepared from the antrum and fundus of guinea-pig stomach. Electrical responses of circular muscle cells were recorded using glass capillary microelectrodes filled with 3 M KCI. 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 recorded from the antral and fundic circular muscle strips with intact mucosa were suppressed dose-dependently by the application of noradrenaline, whereas those recorded from the mucosa-free strips were potentiated in a dose-dependent manner. 2) The inhibitory influences on the contractile activities in the normal intact strips were developed via both ${\alpha}-adrenoceptors\;and\;{\beta}-adrenoceptors$, while the excitatory influences in the mucosa-free strips resulted from the strong excitatory effect via ${\alpha}-adrenoceptors$ and the weak inhibitory effect via ${\beta}-adrenoceptors$. 3) Noradrenaline produced hyperpolarization of membrane potential, and increased the amplitude and the maximum rate of rise of slow waves in the mucosa-free strips of antral and fundic circular muscle. 4) Apamin blocked the appearance of the component of initial suppression of spontaneous phasic contractions observed in the mucosa-free strips of antral circular muscle after the application of noradrenaline. 5) The inhibitory influences on the contractile activities in the normal strips with intact mucosa remained unaffected even in the strip with separate mucosa, in which mucosa and muscle layer were mechanically disconnected . From the above results, following conclusions could be made. (1) There are no regional differences between the effects of noradrenaline on the antral circular muscle and those on the fundic circular muscle. (2) Excitatory responses to noradrenaline observed in the mucosa-free strip result from the dominant ${\alpha}-excitatory$ and tile weak ${\beta}-inhibitory$ action of noradrenaline. (3) Inhibitory responses to noradrenaline in the normal strips with intact mucosa develop via both ${\alpha}-inhibitory\;and\;{\beta}-inhibitory$ actions.

• Science of Emotion and Sensibility
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• v.17 no.2
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• pp.101-110
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• 2014

High-frequency is sound produced in non-audible area, which couldn't be heard in daily life. The frequency range above 22Khz is called 'high-frequency' and its components are called 'HFC(High-Frequency Components)'. It is known that ocean wave sound is rich in HFC, because it brings serenity and causes ${\alpha}$-waves in human mind. When this natural sound is combined with high-frequency, it seems to give a pleasurable feeling, indicated by an ${\alpha}$-wave increase and a ${\beta}$-wave decrease. We call this phenomena "the hypersonic effects". In this experiment, subjects listened to the ocean wave sound simultaneously with corresponding frequencies similar to ocean wave frequency components created artificially in a electric circuit. Brain waves were measured by an EEG system with 8 channels using 8 electrodes on Fp1, Fp2, F3, F4, T3, T4, O1, and O2. The results showed that ${\alpha}$-wave increase and ${\beta}$-wave decrease were statistically significant while subjects were listening to the ocean wave sound along with the high frequency components, reflecting the hypersonic effect.

• Horticultural Science & Technology
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• v.34 no.3
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• pp.472-487
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• 2016

This study aimed to determine the effects of floral fragrances on human brain waves and moods. A total of 44 subjects participated in this experiment. Group 1 consisted of 11 male and 14 female college students with a mean age of 24.5 years (${\pm}2.23$) and Group 2 consisted of 10 males and 9 females with a mean age of 54.3 years (${\pm}2.98$). Subjects were exposed to floral fragrances of Rosa hybrida, 'Hera' (hereafter referred to as "rose"), Cymbidium faberi (hereafter referred to as "orchid"), or odorless control flowers (hereafter referred to as "control"). Experiments took place in three rooms (rose, orchid, and control). Electroencephalographs (EEGs) were recorded during exposure to the odors and the data were processed using quantitative electroencephalographic (QEEG) techniques. The changing EEG patterns were analyzed by brain mapping and compressed spectral arrays, and the subjects' preferences (hedonic evaluations) were quantified with an A1 index. Increased activation of absolute alpha waves was verified on six of the eight EEG channels, with the right frontal and left occipital lobes exhibiting no changes and the left parietal region showing the greatest activation. According to the QEEG measurements in the electrode sites over the frontal, temporal, parietal, and occipital lobes, the strongest absolute alpha waves were induced in the parietal lobes, followed by the temporal lobes, with the other lobes showing no significant changes. On brain maps, the orchid fragrance induced greater absolute alpha and absolute mid-beta activities compared with the rose and control fragrances, and the rose fragrance induced high absolute mid-beta activation. To identify emotional responses to floral fragrances, the subjects were requested to fill in a questionnaire and the resulting odor-related emotional descriptors were analyzed using semantic differential and factor analysis. Principal component analysis identified "elegant" as the first principal component describing the floral fragrance, followed by "refreshing" and "aromatic." The subjects gave orchid higher scores for "elegant" and "refreshing," while finding rose more "aromatic." Differences in hedonic evaluation revealed by the A1 index appeared in the 65-115 sec range of scent exposure time. The subjects with ages of around 50 years showed olfactory preferences throughout the entire experimental time of 160 sec, most markedly in the later time segment (115-165 sec), showing an increasing preference with increasing exposure time. We conclude that rose fragrance can improve concentration by creating an aromatic environment conducive to a concentrated and calm state of mind, and orchid fragrance can make people feel pampered and relaxed by creating an elegant and refreshing environment.