• 한국안전학회지
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• 제26권3호
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• pp.83-90
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• 2011

It is well known that urgency resulted from time stress can be a great cause to industrial accidents. Therefore, time stress has been studied in the aspect of macroscopic view, namely industrial safety management, but has not been studied in microscopic view such as psychophysiological approach. Among diverse psychophysiological indices, Electroencephalogram(EEG) would be on of the most objective psychophysiological research technique on human errors though few research has been taken yet. This study aimed to get characteristics of human error while committing a simple arithmetic addition task by utilizing the power spectrum technique of EEG data. Each experiment was composed of 2 tasks under different condition - with and without time stress. As subjects, 5 young undergraduate students in their early twenties participated in this study. The results advocated a well-known fact that time stress downgrades the performance of human workers. However, correct answer rate and response time were not significantly influenced by time stress factor which might be explained by the constructural factor adopted in the present study. As in the previous studies, among various EEG-related measures, relative band power ratios of ${\alpha}$ and ${\beta}$ waves to sum of ${\alpha}$,${\beta}$,${\theta}$ wave powers, namely $P_{{\alpha}/({\alpha}+{\beta}+{\theta})}$ and $P_{{\beta}/({\alpha}+{\beta}+{\theta})}$ seemed to be the most effective measures to grasp variation of brain activities in time-stressed situation so that discussions were expanded about their variations.

• 대한의용생체공학회:의공학회지
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• 제24권6호
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• pp.487-494
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• 2003

수면뇌파의 해석에 있어서 수면단계는 뇌파의 특성파 검출에 특히 중요하다. 수면단계는 여러 수면질환의 진단에 가장 기초적일 단서를 제공한다. 본 연구에서 수면뇌파 신호를 이산 웨이브렛 변환 뿐 만 아니라 퓨우리에 변환, 연속 웨이브렛 변환을 이용해서 해석하였다. 제안된 시스템 방범인 퓨우리에와 웨이브렛은 수면뇌파의 중요한 특성파(유파, 수면방추파, K복합, 구파 REM) 검출을 위해서 수면상태를 분석했다. 수면뇌파 분석에는 Daubechies 웨이브렛 변환 방법과 고속 퓨우리에를 이용했다. 모의실험결과 신경망 시스템이 특성 파형의 분류에 높은 성능을 발휘함을 알 수 있었다.

• 한국의류학회지
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• 제44권5호
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• pp.824-836
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• 2020

This study investigated the effects of textile attachments on electroencephalogram using 20 persons (10 males and 10 females). Four types of attachment cushions were manufactured by changing the shell fabric (cotton and microfiber) and interlining (synthetic loose fiber and buckwheat). This was done using BIOS-S8 (BioBrain Inc., Korea), an 8-channel polygraph for multi-body signal measurement, to measure EEG. Data were analyzed using the SPSS 24.0 statistical program. EEG values were significantly activated according to gender, particularly when the subjects' eyes were open. For the male cases, 'RT', 'RAHB' values were highly activated and for the female cases, 'RA', 'RB', 'RG', 'RFA', 'RST', 'RLB', 'RMB', 'RST', 'RMT' values were highly activated. Examining the differences in EEG according to type of attachment indicated no significant difference in both sexes. However, in cases of females with their eyes closed, the 'RSA' index was quite different in the left occipital lobe (O1), and when their eyes were open, the 'RFA' in the right frontal lobe (F4) showed a significant difference. However, there was no obvious correlation between the activation of EEG and the subjective preference of textile attachments.

• The Journal of Korean Physical Therapy
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• 제32권6호
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• pp.365-371
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• 2020

Objective: To investigate the action observation effects of functional electrical stimulation (FES) on the communication between motor cortex and muscle through corticomuscular coherence (CMC) analysis. Methods: Electroencephalogram (EEG) and electromyogram (EMG) of 27 healthy, nonathlete subjects were measured during action observation, FES, and action observation with FES, which lasted for 7sper session for 10 times. All trials were repeated for 30 times. Simultaneously measured EEG raw data and rectified EMG signals were used to calculate CMC. Only confidence limit values above 0.0306 were used for analysis. CMC was divided into three frequency domains, andthe grand average coherence and peak coherence were computed. Repeated ANOVA was performed to analyze the coherence value difference for each condition's frequency band. Results: CMC showed significant differences in peak coherence and average coherence between the conditions (p<0.05). Action observation application with FES in all frequency band showed the highest peak and average coherence value. Conclusions: The results of this study are assumed to be the combination of increased eccentric information transfer from the sensorymotor cortex by action observation and an increased in concentric sensory input from the peripheral by the FES, suggesting that these are reflecting the sensorimotor integration process.

• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2022년도 제66차 하계학술대회논문집 30권2호
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• pp.19-22
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• 2022

In this work, we studied consumers' attractiveness/usefulness perceptions (CAUP) of online commerce product photos when exposed to alternative dark/light user interface (UI) modes. We analyzed time-series EEG data from 31 individuals and performed neuroscience mining (NSM) to ascertain (a) how the CAUP of products differs among UI modes; and (b) which deep learning model provides the most accurate assessment of such neuroscience mining (NSM) business difficulties. The dark UI style increased the CAUP of the products displayed and was predicted with the greatest accuracy using a unique EEG power spectra separated wave brainwave 2D-ConvLSTM model. Then, using relative importance analysis, we used this model to determine the most relevant power spectra. Our findings are considered to contribute to the discovery of objective truths about online customers' reactions to various user interface modes used by various online marketplaces that cannot be uncovered through more traditional research approaches like as surveys.

• 전자공학회논문지 IE
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• 제43권1호
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• pp.16-24
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• 2006

본 논문에서는 생체신호의 발생을 자유롭게 조절 할 수 있는 전정기관으로부터 생성된 전기신호를 추출하여 window discriminator로 필요한 신호를 선택한 후, BCI 시스템을 적용하여 정밀하고 정확한 제어가 가능하고 멀티채널을 이용하여 데이터를 처리할 수 있는 통합 시스템을 구현하였다. 전정신경세포의 흥분신호를 검출하는 전치증폭기는 측정된 이득이 47.6dB, 왜율은 100 Hz에서 측정 시 0.005%이었으며, 입력임피던스 특성은 12M$\Omega$이었다. Window discriminator는 2개의 CPU를 사용하여 역할을 분담함으로써 처리 속도를 증가시켰고, ADC 샘플링 주파수는 87kHz이었으며, 기존 시스템보다 분해능이 2배, 변별 오차는 10배가 향상되었음을 알 수 있었다. 제안된 방법이 뇌파분석법 보다 100ms동안 축적된 데이터양이 약 100배 정도 감소되었음을 입증하였다.

• 동력기계공학회지
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• 제14권4호
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• pp.29-36
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• 2010

인체에 음향진동장치에 의하여 자극을 가하였을 경우 영향을 고찰한다. 5명의 건강한 남자 대학생을 대상으로 하여, 3가지 형태의 음악을 음향과 진동자극의 신호원으로 사용해서 실험을 행하였다. 모든 피험자에 대하여, 자극 전, 음악자극, 진동자극, 자극 후로 나누어 뇌파를 측정하였다. 실험의 모든 피험자의 측정 데이터의 t-검정을 수행하여 유의성이 있는 데이터에 한하여 뇌파를 고찰하였다. 결과로서, 음악과 음향파와 진동자극이 뇌파에 미치는 영향은 음향진동장치에 따른 진동자극 형태, 피험자의 몸과 정신 상태에 따라 현저하게 달라질 수 있다는 것을 알 수 있다. 그리고 적절한 음악과 음향진동장치를 사용하여 특정의 뇌파 상태를 유도 할 수 있음을 확인하였다.

• 생물정신의학
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• 제22권2호
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• pp.87-94
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• 2015

Objectives The power spectral analysis of electroencephalogram has been widely used to reveal the pathophysiology of the alcoholic brain. However, the results were not consistent and the three dimensional study can be hardly found. The purpose of this study was to investigate characteristics of the three dimensional electroencephalographic (EEG) activity of alcohol dependent patients using standardized low resolution electromagnetic tomography (sLORETA). Methods The participants consisted of 30 alcohol dependent patients and 30 normal healthy controls. All the participants were males who had refrained from alcohol at least one month and were not taking any medications. Thirty two channel EEG data was collected in the resting state with eyes-closed condition during 30 seconds. The three dimensional data was compared between two groups using sLORETA for delta, theta, alpha, beta1, beta2, and beta3 frequency bands. Results sLORETA revealed significantly increased brain cortical activity in alpha, beta1, beta2, and beta3 bands each in alcohol dependent patients compared to normal controls. The voxels showing the maximum significance were in the left transverse temporal gyrus, left superior temporal gyrus, left anterior cingulate, and left fusiform gyrus in alpha, beta1, beta2, and beta3 bands respectively. Conclusions These results suggest that chronic alcohol intake may cause neurophysiological changes in cerebral activity. Therefore, the measuring of EEG can be helpful in understanding the pathophysiology of cognitive impairements in alcohol dependence.

• 성인간호학회지
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• 제25권6호
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• pp.644-654
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• 2013

Purpose: The purpose of this study was to examine the effects of aroma foot reflexology massage on mood states specifically depression and brain waves of elderly women with osteoarthritis. Methods: The study was a nonequivalent control group non-synchronized design. The participants were 62 elderly women with osteoarthritis. The instruments were the Korean-Profile of Mood States-Brief for mood states and 8-channel EEG (Electroencephalogram) system for brain waves. Data were collected from March to May, 2012. Twenty-six participants were assigned to the treatment group and twenty-six to the comparison group. The data were analyzed using SPSS/WIN 17.0 version program, and included descriptive statistics, t-test, and ANCOVA. The intervention was conducted three times a week for two weeks. Results: There were significantly improvement in reported depression. s. Brain waves (EEG) increased significantly in F3, T3 of ${\alpha}$ wave and in F4, T3, and P4 of ${\beta}$ wave between the two groups. Conclusion: Aroma foot reflexology massage can be utilized as an effective intervention to decrease depression of mood states, increase of ${\alpha}$, and ${\beta}$ brain wave on woman elderly with osteoarthritis.

• 대한의용생체공학회:의공학회지
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• 제36권4호
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• pp.95-102
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• 2015

Epilepsy is a chronic neurological disease which produces repeated seizures. Over 30% of epileptic patients cannot be treated with anti-epileptic drugs, and surgical resection may cause loss of brain functions. Seizure suppression by electrical stimulation is currently being investigated as a new treatment method as clinical evidence has shown that electrical stimulation to brain could suppress seizure activity. In this paper, design of a real-time closed-loop neurostimulation system for epileptic seizure suppression is presented. The system records neural signals, detects seizures and delivers electrical stimulation. The system consists of a 6-channel electrode, front-end amplifiers, a data acquisition board by National Instruments, and a neurostimulator and Generic Osorio-Frei algorithm was applied for seizure detection. The algorithm was verified through simulation using electroencephalogram data, and the operation of whole system was verified through simulation and in- vivo test.