• 한국전자통신학회논문지
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• 제9권5호
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• pp.589-594
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• 2014

인간은 집중할 때 유발되는 특정한 뇌파가 있는 것으로 알려져 있다. 본 논문에서는 인간의 집중과 관련된 뇌파를 분석하는 것을 목표로 하여, 집중을 유발할 수 있는 도구로 시각자극을 설정하였다. 즉 시각자극으로 구성된 과제를 제시하여 피험자가 집중할 수 있도록 하였다. 피험자로부터 유발되는 뇌파는 전극의 위치에 따른 채널별로 계측하였고, 계측한 뇌파는 주파수대역별로 나누어 분석하였다. 그 중에서도 특히 SMR, Mid-beta, Theta파에 해당되는 주파수대역의 파워 스펙트럼으로 분석하였고, 그 특성을 분석한 결과를 제시하였다.

• 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.

• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2021년도 제64차 하계학술대회논문집 29권2호
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• pp.305-307
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• 2021

Alzheimer's Disease (AD) is a cognitive disorder characterized by memory impairment that can be assessed at early stages based on administering clinical tests. However, the AD pathophysiological mechanism is still poorly understood due to the difficulty of distinguishing different levels of AD severity, even using a variety of brain modalities. Therefore, in this study, we present a hybrid EEG-fNIRS modalities to compensate for each other's weaknesses with the help of Machine Learning (ML) techniques for classifying four subject groups, including healthy controls (HC) and three distinguishable groups of AD levels. A concurrent EEF-fNIRS setup was used to record the data from 41 subjects during Oddball and 1-back tasks. We employed both a traditional neural network (NN) and a CNN-LSTM hybrid model for fNIRS and EEG, respectively. The final prediction was then obtained by using majority voting of those models. Classification results indicated that the hybrid EEG-fNIRS feature set achieved a higher accuracy (71.4%) by combining their complementary properties, compared to using EEG (67.9%) or fNIRS alone (68.9%). These findings demonstrate the potential of an EEG-fNIRS hybridization technique coupled with ML-based approaches for further AD studies.

• 대한인간공학회지
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• 제13권2호
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• pp.43-48
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• 1994

Among many kinds of odors, some are known to have effects of sedation or stimulation on brain activity. In this study, brain activity levels affected by four kinds of fragrance0lemon, lavender, jasmine, and rose-were tested using EEG recording. In the first experiment, the quality of alpha wave was examined under controlled rest condition. In the second experiment, the event-related potential (ERP) and contingent negative variation (CNV) were investigated during a simple reaction tasks (SRT) against auditory signal. EEG data obtained for the rest condition were analyzed suing "3-Dimensional Viewer)" which was developed by ourselves to show the chaotic attractor of the signal. Power spectrum were also calculated using FET. EEG data obtained during the SRT were analyzed by comparing CNV amplitudes about each odor condition. Results confirmed the sedative effect of the lemon and the lavender, and the stimulative effect of the jasmine and the rose.

• IEIE Transactions on Smart Processing and Computing
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• 제4권2호
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• pp.97-102
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• 2015

In this paper, an extension of the standard common spatial pattern (CSP) algorithm using the strong uncorrelated transform (SUT) is used in order to extract the features for an accurate classification of the left- and right-hand motor imagery tasks. The algorithm is designed to analyze the complex data, which can preserve the additional information of the relationship between the two electroencephalogram (EEG) data from distant channels. This is based on the fact that distant regions of the brain are spatially distributed spatially and related, as in a network. The real-world left- and right-hand motor imagery EEG data was acquired through the Physionet database and the support vector machine (SVM) was used as a classifier to test the proposed method. The results showed that extracting the features of the pair-wise channel data using the strong uncorrelated transform complex common spatial pattern (SUTCCSP) provides a higher classification rate compared to the standard CSP algorithm.

• 아동학회지
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• 제36권6호
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• pp.85-100
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• 2015

This study divided elementary school 6th graders of into a higher academic achievement group (n=19) and a lower academic achievement group (n=19) in order to examine the tendency of left and right hemisphere preferences, characteristics and relationships of learning ability factors by means of EEG. For this purpose, brain waves in performing higher cognitive tasks for 5 min. were measured with a two-channel (Fp1, Fp2) EEG measurement system and hemisphere preference was measured by means of a questionnaire. Our results were as follows. First, hemisphere preference indicated that the higher group showed a left hemisphere tendency and the lower group indicated a right hemisphere tendency. Second, the first learning ability test found that the higher group performed its task rapidly with higher levels of concentration and cognitive strength and lower loading and the lower group conducted its task more slowly with lower levels of concentration and cognitive strength and higher loading. The second test showed that the higher group performed its task rapidly with lower levels of concentration.

• 한국전자통신학회논문지
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• 제10권6호
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• pp.757-762
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• 2015

본 논문은 색온도가 글씨 쓰기 과제 수행과 뇌파에 미치는 영향을 알아보고자 2013년 7월부터 9월까지 초등학생 아동 24명을 대상으로 실시하였다. 색온도의 고정과 유지를 위해 준비된 실험실에서 주황색등과 백색등에 따른 과제수행시간의 측정과 뇌파를 측정하여 분석하였다. 연구 결과 알파파, 베타파, 하이베타파의 출현이 백색등에서 높게 나타났으나 과제수행 시간은 주황색등에서 유의하게 빠른 수행을 보였다. 이는 기존의 낮은 색온도는 안정과 이완에 전형적인 색온도로 여겨졌으나 심인적인 요인과 과제의 특성과 종류에 따른 다양한 활용은 학습과 작업의 능률에 긍정적인 영향을 줄 수 있음을 제시했다.

• 한국전자통신학회논문지
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• 제16권1호
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• pp.89-94
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• 2021

본 논문에서는 학습 과제 수행 시 청각 자극이 뇌에 미치는 영향을 확인하기 위하여 뇌파 계측 실험을 통해 얻은 데이터로 분석한 결과를 제시하였다. 피험자가 수학적 과제를 해결하는 동안, 피험자의 선호도에 따라 구분한 선호 음악 및 비선호 음악을 청각 자극으로 제시하였으며, 수학적 과제는 암기형 및 절차형 과제로 구분하여 뇌파를 측정하였다. 이를 집중력과 관련된 뇌파의 주파수 대역인 세타파, SMR파 및 중간베타파로 나누어 상대 파워 스펙트럼 값을 비교하였다. 본 논문의 결과로는 무음악과 선호 음악 및 무음악과 비선호 음악을 비교한 경우에서 유의한 차이를 나타내는 채널을 관측할 수 있었으며, 공통적으로 전두엽 부위의 채널인 F3 및 F4에서 평균의 차이를 나타냈다. 유의미한 차이를 나타낸 채널들에서도 음악이 없는 경우보다 음악이 제시된 경우의 파워가 더 크게 나타났으며, 선호도에 따라서는 선호 음악이 비선호 음악의 경우보다 두뇌의 활성도가 크게 나타난다는 사실을 실험결과로부터 확인할 수 있었다.

• 한국컴퓨터정보학회논문지
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• 제15권10호
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• pp.105-112
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• 2010

의료 분야의 감성 및 심리 치료를 확장하여 이와 관련된 기술을 일반 생활에 접목하고, 또한 생체신호를 이용하여 보다 쾌적한 삶의 환경을 구축하려는 연구가 활발하게 진행되고 있다. 본 논문에서는 뇌전도(EEG : electroencephalogram)와 심전도(ECG : electrocardiogram)의 심박변이도(HRV : Heart Rate Variability)의 패턴을 분석하여 평온, 집중, 긴장, 우울의 네 가지 감성을 분류하고 추론하기 위한 감성추론시스템을 설계하고 구현하였다. 많은 감성 인식 연구가 얼굴이나 음성의 인식에 의하여 이루어지고 있으며, 생체신호를 이용한 추론 연구의 경우에도, 뇌전도나 심전도 등의 단일 생체신호의 분석에 의하여 이루어지고 있다. 본 논문에서는 단일 생체신호가 아닌 뇌전도와 심전도신호를 조합하여 복합적으로 분석함으로서 단일 생체신호의 분석 연구보다 추론의 정확도를 높였으며, 감성 추론을 위한 엔진으로지도 학습과 비지도학습의 RBFN(Radial Basis Function Network) 신경망을 적용하여 오류역전파 알고리즘의 지역 최소점과 수렴속도가 느린 단점을 보완하였다.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제19권2호
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• pp.117-139
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• 2015

For the purpose of determining neurophysiological mechanism of math anxiety, we conducted an EEG measurement for 22 sixth grade elementary students including 11 students with high math anxiety (HMA group), and 11 students with low math anxiety (LMA group). We found that in HMA group, delta wave was significantly generated from the right frontal lobe, and in LMA group, four paths are clearly connected while they perform math tasks (right inferior occipital gyrus ${\leftrightarrow}$ left superior parietal lobule /left middle frontal gyrus ${\leftrightarrow}$ left inferior parietal lobule /left middle frontal gyrus ${\leftrightarrow}$ right inferior parietal lobule / right middle frontal gyrus ${\leftrightarrow}$ right inferior parietal lobule). According to the above results we suggest that math anxiety is related to emotions associated with pain, reduces working memory and has a negative effect on math performance.