• Science of Emotion and Sensibility
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• v.27 no.2
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• pp.105-112
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• 2024

Forward head posture (FHP) is a representative postural deformation problem in people today, causing various physical and mental problems, but the effect of FHP on discomfort or distraction during rest is not well known. Accordingly, this study aims to demonstrate the effect of FHP on these brain functions by analyzing brain wave signals at rest. Thirty-three heavy users of computers participated in this study, and all of them exhibited functional FHP when using computers. All participants performed using both normal posture and FHP, and their brain waves were measured at rest while maintaining each posture for five minutes without stimulation. Brain wave signals were acquired using EEG with 32 channels, and through frequency analysis, changes in delta and beta waves, known to be closely related to discomfort and attention, were compared and analyzed depending on the posture. As a result, FHP showed a significant decrease in delta waves in nine channels compared to the normal posture, and a significant increase in beta waves in 14 channels, showing that FHP does affect brain function at rest. These changes are consistent with those that occur under conditions of psychological discomfort and distraction, and they appear to be because the increased discomfort caused by musculoskeletal changes in the FHP also affects brain activity. These can provide important results showing that posture correction can help improve brain function and psychological state at rest.

• Science of Emotion and Sensibility
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• v.22 no.3
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• pp.3-20
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• 2019

With advancements in technology of virtual reality, it is used for various purposes in many fields such as medical care and healthcare, but as the same time there are also increasing reports of nausea, eye fatigue, dizziness, and headache from users. These symptoms of motion sickness are referred to as cybersickness, and various researches are under way to solve the cybersickness problem because it can cause inconvenience to the user and cause adverse effects such as discomfort or stress. However, there is no official standard for the causes and solutions of cybersickness at present. This is also related to the absence of tools to quantitatively measure the cybersickness. In order to overcome these limitations, this study proposed quantitative and objective cybersickness evaluation method. We measured 128-channel EEG waves from ten participants experiencing visually stimulated virtual reality. We calculated the relative power of delta and alpha in 11 regions (left, middle, right frontal, parietal, occipital and left, right temporal lobe). Multiple regression models were obtained in a stepwise manner with the motion sickness susceptibility questionnaire (MSSQ) scores indicating the susceptibility of the subject to the motion sickness. A multiple regression model with the highest under the area ROC curve (AUC) was derived. In the multiple regression model derived from this study, it was possible to distinguish cybersickness by accuracy of 95.1% with 11 explanatory variables (P_D.MF, P_D.LP, P_D.MP, P_D.RP, P_D.MO, P_A.LF, P_A.MF, P_A.RF, P_A.LP, P_A.RP, P_A.MO). In summary, in this study, objective response to cybersickness was confirmed through 128 channels of EEG. The analysis results showed that there was a clearly distinguished reaction at a specific part of the brain. Using the results and analytical methods of this study, it is expected that it will be useful for the future studies related to the cybersickness.

• Journal of Biomedical Engineering Research
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• v.20 no.1
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• pp.81-90
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• 1999

This paper describes an EEG(electroencephalogram) software for two-channel cerebral function monitoring system to detect the cerebral ischemia. In the software, two-channel bipolar analog EEG signals are digitized and from the signals various EEG parameters are extracted and displayed on a monitor in real-time. Digitized EEG signal is transformed by FFT(Fast Fourier transform) and represented as CSA(compressed spectral array) and DSA(density spectral array). Additional 5 parameters, such as alpha ratio, percent delta, spectral edge frequency, total power, and difference in total power, are estimated using the FFT spectra. All of these are effectively merged in a monitor and displayed in real-time. Through animal experiments and clinical trials on men, the software is modified and enhanced. Since the software provides raw EEG, CSA, DSA, simultaneously with additional 5 parameters in a monitor, it is possible to observe patients multilaterally. For easy comparison of patient's status, reference patterns of CSA, DSA can be captured and displayed on top of the monitor. And user can mark events of surgical operation and patient's conditions on the software, this allow him jump to the points of events directly, when reviewing the recorded EEG file afterwards. Other functions, such as forward/backward jump, gain control, file management are equipped and these are operated by simple mouse click. Clinical tests in a university hospital show that the software responds accurately according to the conditions of patients and medical doctors can use the software easily.

• Sleep Medicine and Psychophysiology
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• v.15 no.2
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• pp.71-76
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• 2008

Introduction: In this study, we compared sleep structure, EEG characteristic of pediatric obstructive sleep apnea (OSA) and normal controls which were matched in sex and age. Methods: Fifteen children (male：female=4：11) who complained snoring and were suspected to have sleep apnea and their age and sex matched normal controls (male：female=5：10) have been done nocturnal polysomnography (NPSG). Sleep parameters, sleep apnea variables and relative spectral components of EEG from NPSG have been compared between both groups. Results: Pediatric OSA group were distinguished from normal controls in terms of apnea index, respiratory disturbance index and nadir of oxyhemoglobulin desaturation. Pediatric OSA group showed increased percent of sleep stage 1, decreased rapid eye movement sleep percent and increased delta power in O1 EEG channel. However other sleep parameters and spectral powers were not different between two groups. Conclusion: In pediatric OSA group, sleep structure parameter disruption may be not prominent as the previous studies for adult OSA group because of including mild OSA data in diagnostic criteria. In addition, EEG changes might not be distinct due to low arousal index compared to adult OSA patients. We can observe general characteristics and particularity of pediatric OSA through this study.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.5
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• pp.608-616
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• 2017

The purpose of this study was to compare how three kinds of emotionally different music impacted on the emotion and arousal by measuring EEG. The research method was to compare the measurement of the background EEG on Fp1 and Fp2 before, while and after listening using a 2-channel EEG device with various experimental groups aging from 20s to 50s. The results were as follows. 1) At both Fp1 and Fp2, the amplitude of alpha(8-13Hz), SMR(12-15Hz), low beta, high beta, and ${\alpha}/-{\beta}$significantly increased in all music, while at Fp2 only, theta and ??/SMR increased meaningfully.2) At right prefrontal cortex(Fp2), all bands of EEG predominated while and after listening to all songs over Fp1 except for the delta of funeral march which predominated while listening to Fp1.3) The music with a noticeably high alpha value and increased activity was Prelude. These results suggested that Prelude induced brain activity along with relaxation, and the emotionally heavy burden of funeral march decreased the activity of the left brain. This research revealed that feeling emotional change by listening to music was due to the fact that music influenced the brain activity inducing the change of emotion and arousal.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.482-492
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• 2019

This study began with the assumption that the phonetics-centered interpretation of 100 Chinese characters would enhance thinking ability and comprehension. For this purpose, two experimental groups and a comparative group were recruited from the graduate students from June 3, 2017 to February 22, 2018. The experimental group participated in the phonetics-centered Chinese character lecture for 4 hours per week for 6 weeks for a total of 24 hours. QEEG were measured before and after the phonetics-centered Chinese character lecture. A total of 18 subjects ( nine subjects in the experimental group and nine comparative subjects) were included in the study, and the difference between before and after the QEEG of the experimental and comparative groups was analyzed, respectively. The conclusions drawn from this study are as follows. First, the Chinese character lecture changed brain waves. Second, the LORETA analysis before and after the lecture in the experimental group significantly decreased the delta wave in the brain region (Broadmann 40) associated with the meaning of language and phonology. This study result is meaningful because it shows the significant changes of EEG via the lecture.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1998.11a
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• pp.158-162
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• 1998

향에 의해 유발되는 감성에 대한 중추신경계 및 자율신경계의 반응의 변화를 측정하기 위해 안정시키는 향과 각성시키는 향을 사용하여 주관적 평가와 동시에 시행하였다. 안정시키는 향으로 1% Lavendar 향을 사용하였고, 각성시키는 향으로 0.8% Jasmin 향을 사용하였으며, 안정상태를 향자극 전후에 측정하여 대조군으로 사용하였다. 중추신경계의 지표로 뇌파측정을 하였고 뇌파의 전극은 international 10-20 system에서 4 채널을 사용하였으며, 자율신경계의 지표로는 심전도, heart rate, 피부저항, 피부온도를 기록하였다. 뇌파의 분석은 Fast Fourier Transform analysis의 power spectra로 하였고, 그 frequency bands는 theta(4-8Hz), alpha(8-l3Hz), beta(14-30Hz)로 하였다 또한 심전도를 이용하여 심전도 상의 연속적인 R-R peak간 시간간격을 시계열 데이터로 재구성한 Heart rate variability 분석도 하였다. HRV 분석을 보다 정확히 할 수 있도록 호흡이 심전도에 미치는 영향을 제거하기 위하여 호흡을 분당 20회로 일정하게 하였다 생체신호 측정과 동시에 실시한 주관적 검사에서 lavendar 향은 친숙하게, jasmin 향은 활기차고 상쾌하고 유쾌하게 평가되었다. 뇌파 분석에서 lavendar 향을 주었을 때 theta의 증가 양상을 보였으며, Jasmin 향을 주었을 때는 모든 채널에서 beta 파의 증가 양상을 보였다. 또한 HRV 분석 결과 부교삼신경의 활동성이 부각되는 HF/LF의 값이 lavendar에서는 대조 자극보다 높게 나타났으며, jasmin에서는 대조자극보다 낮은 값이 나타나는 경향을 보였다. 결론적으로 안정과 각성의 후각 자극으로 인한 감성의 변화를 뇌파와 자율신경계 등의 생체지표로 관찰할 수 있었다.정하는 감성요인의 차이를 알 수 있었으며 또한 essential oil에서는 성별 차이가 없는데 반해 페르몬 향의 경우 성별의 차이를 나타내었다.. 방법을 타액과 혈청내 testosterone 농도 측정에 응용하여 RIA의 결과와 비교하여 본 바 상관관계가 타액에서 r=0.969, 혈청에서 r=0.990으로 두 결과가 잘 일치하였다. 본 실험에서 측정된 한국인 여성의 타액내 testosterone농도는 107.7$\pm$12.0 pmol／l이었고, 남성의 타액내 농도는 274.2$\pm$22.1 pmol／l이었다. 이상의 결과로 보아 본 연구에서 정립된 EIA 방법은 RIA를 대신하여 소규모의 실험실에서도 활용할 수 있을 것으로 사려된다.또한 상실기 이후 배아에서 합성되며, 발생시기에 따라 그 영향이 다르고 팽창과 부화에 관여하는 것으로 사료된다. 더욱이, 조선의 ${\ulcorner}$구성교육${\lrcorner}$이 조선총독부의 관리하에서 실행되었다는 것을, 당시의 사범학교를 중심으로 한 교육조직을 기술한 문헌에 의해 규명시켰다.nd of letter design which represents -natural objects and was popular at the time of Yukjo Dynasty, and there are some documents of that period left both in Japan and Korea. "Hyojedo" in Korea is supposed to have been influenced by the letter design. Asite- is also considered to have been "Japanese Letter Jobcheso." Therefore, the purpose of this study is to loo

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.10
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• pp.1139-1144
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• 2014

Recently, the meditation is getting a major concern because of the trend of wellbeing. The various meditation methods are introduced, but, we need to take an appropriate method for himself or herself. Especially, the numbers of meditators who are using meditation music while they are meditating are increasing. Some people say it is helpful, but others don't. Therefore, I have studied the impact of the meditation music in this paper. I have compared between the meditation with the music and without the music by measuring the channels of left and right hemisphere of prefrontal lobe with 14-channel EEG device. For the result, I have found that there are great difference between two experiments.

• Science of Emotion and Sensibility
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• v.19 no.4
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• pp.119-126
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• 2016

In this study, we investigated the effects of mouth breathing on brain activity through electroencephalogram (EEG). EEG was performed on 12 healthy volunteers of age ranging from 21 to 27 years (male: female = 6:6, non-smoker). Brain waves on resting state (Rest_N/Rest_M) and auditory-language stimuli state (Eng_N/Eng_M) were recorded during mouth and nose breathing. Four different regions (R1~R4) were classified based on the brain functionality. And each channel (e.g., Pf1 and Pf2) and frequency (${\alpha}$, ${\beta}$, ${\gamma}$, and ${\theta}$) were analyzed using their absolute power ratios of fast Fourier transform (FFT). The results showed that there was no significant difference between Rest_N and Rest_M. Eng_N had significantly higher brain activity than Rest_N; on the other hand, there was no significant difference between Rest_M and Eng_M. These results demonstrate that mouth-breathing on resting state does not induce any significant effects on brain activity and/or functionality, even though it causes subtle temporary inconvenience. In addition to the uncomfort, the brain activity can be adversely influenced by mouth-breathing, which could lower the cognitive skills under certain circumstances.

• Sleep Medicine and Psychophysiology
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• v.17 no.1
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• pp.41-49
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• 2010

Unlike the case of adult obstructive sleep apnea syndrome (OSAS), there was no consistent finding on the changes of sleep architecture in childhood OSAS. Further understanding of the sleep electroencephalogram (EEG) should be needed. Non-linear analysis of EEG is particularly useful in giving us a new perspective and in understanding the brain system. The objective of the current study is to compare the sleep architecture and the scaling exponent (${\alpha}$) from detrended fluctuation analysis (DFA) on sleep EEG between OSAS and normal children. Fifteen normal children (8 boys/7 girls, 6.0${\pm}4.3$2.2 years old) and twelve OSAS children (10 boys/2 girls, 6.4${\pm}4.3$3.4 years old) were studied with polysomnography (PSG). Sleep-related variables and OSAS severity indices were obtained. Scaling exponent of DFA were calculated from the EEG channels (C3/A2, C4/A1, O1/A2, and O2/A1), and compared between normal and OSAS children. No difference in sleep architecture was found between OSAS and normal controls except stage 1 sleep (%) and REM sleep latency (min). Stage 1 sleep (%) was significantly higher and REM latency was longer in OSAS group (9.3${\pm}4.3$4.3%, 181.5${\pm}4.3$59.9 min) than in controls (5.6${\pm}4.3$2.8%, 133.5${\pm}4.3$42.0 min). Scaling exponent (${\alpha}$) showed that sleep EEG of OSAS children also followed the 'longrange temporal correlation' characteristics. Value of ${\alpha}$ increased as sleep stages increased from stage 1 to stage 4. Value of ${\alpha}$ from C3/A2, C4/A1, O1/A2, O2/A1 were significantly lower in OSAS than in control (1.36${\pm}4.3$0.05 vs. 1.41${\pm}4.3$0.04, 1.37${\pm}4.3$0.04 vs. 1.41${\pm}4.3$0.04, 1.37${\pm}4.3$0.05 vs. 1.41${\pm}4.3$0.05, and 1.36${\pm}4.3$0.07 vs. 1.41${\pm}4.3$0.05, p<0.05). Higher stage 1 sleep (%) in OSAS children was consistent finding with OSAS adults. Lower $'{\alpha}'$ in OSAS children suggests decrease of self-organized criticality or the decreased piling-up energy of brain system during sleep in OSAS children.