• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.5
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• pp.197-206
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• 2014

Motor imagery based Brain-computer Interface(BCI), which has recently attracted attention, is the technique for decoding the user's voluntary motor intention using Electroencephalography(EEG). For classifying the motor imagery, event-related desynchronization(ERD), which is the phenomenon of EEG voltage drop at sensorimotor area in ${\mu}$-band(8-13Hz), has been generally used but this method are not free from the performance degradation of the BCI system because EEG has low spatial resolution and shows different ERD-appearing band according to users. Common spatial pattern(CSP) was proposed to solve the low spatial resolution problem but it has a disadvantage of being very sensitive to frequency-band selection. Discriminative filter bank common spatial pattern(DFBCSP) tried to solve the frequency-band selection problem by using the Fisher ratio of the averaged EEG signal power and establishing discriminative filter bank(DFB) which only includes the feature frequency-band. However, we found that DFB might not include the proper filters showing the spatial pattern of ERD. To solve this problem, we apply a band-selection process using CSP feature vectors and linear discriminant analysis to DFBCSP instead of the averaged EEG signal power. The filter selection results and the classification accuracies of the existing and the proposed methods show that the CSP feature is more effective than signal power feature.

• Journal of Biomedical Engineering Research
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• v.24 no.6 s.81
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• pp.487-494
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• 2003

The sleep stages provides the most basic evidence for diagnosing a variety of sleep diseases. for staging sleep by analysis of EEG(electroencephalogram), it is especially important to detect the characteristic waveforms from EEG. In this paper, sleep EEG signals were analyzed using Fourier transform and continuous wavelet transform as well as discrete wavelet transform. Proposeed system methods. Fourier and wavelet for detecting of important characteristic waves(hump, sleep spindles. K-complex, hill wave, ripple wave) in sleep EEG. Sleep EEG data were analysed using Daubechies wavelet transform method and FFT method. As a result of simulation, we suggest that our neural network system attain high performance in classification of characteristic waves.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.8
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• pp.725-730
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• 2013

This paper proposed a novel method for an analysis feature of an Electroencephalogram (EEG) at all channels simultaneously. In a BCI (Brain-Computer Interface) system, EEGs are used to control a machine or computer. The EEG signals were weak to noise and had low spatial resolution because they were acquired by a non-invasive method involving, attaching electrodes along with scalp. This made it difficult to analyze the whole channel of EEG signals. And the previous method could not analyze multiple stimuli, the result being that the BCI system could not react to multiple orders. The method proposed in this paper made it possible analyze multiple-stimuli by grouping the channels. We searched the groups making the largest correlation coefficient summation of every member of the group with a BHS (Binary Harmony Search) algorithm. Then we assumed the EEG signal could be written in linear summation of groups using concentration parameters. In order to verify this assumption, we performed a simulation of three subjects, 60 times per person. From the simulation, we could obtain the groups of EEG signals. We also established the types of stimulus from the concentration coefficient. Consequently, we concluded that the signal could be divided into several groups. Furthermore, we could analyze the EEG in a new way with concentration coefficients from the EEG channel grouping.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2002.06a
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• pp.99-99
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• 2002

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.41 no.3
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• pp.221-229
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• 2004

The Continuous Wavelets Transform project signal f(t) to "Time-scale"plan utilizing the time varied function which called "wavelets". This Transformation permit to analyze scale time dependence of signal f(t) thus the local or global scale properties can be extracted. Moreover, the signal f(t) can be reconstructed stably by utilizing the Inverse Continuous Wavelets Transform. In this paper, the EEG signal is analyzed by wavelets coherence method and the De-noising procedure is represented.

• Proceedings of the KOSOMBE Conference
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• v.1995 no.11
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• pp.282-285
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• 1995

In this paper, we present a feedback structured adaptive RF filter based on the recursive modified Gram-Schmidt algorithm for short-term prediction of EEG signal. And the performance of this proposed filter is compared with those of linear AR model, RF filter, Volterra filter and RBF neural network as single-step prediction and multi-step prediction. The results show the superiority of this proposed filter in prediction of EEG signals.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.736-740
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• 1991

EEG(Electroencephalogram) background signals can be represented as the sun of a conventional AR(Autoregressive) process and an innovation process, or a prediction error process. We have seen that conventional estimation techniques. such as least square estimates(LSE) or Gaussian maximum likelihood estimates(MLE-G) are optimal when the innovation process satisfies the Gaussian or presumed distribution. But when the data are contaminated by outliers, or artifacts, these assumptions are not met and conventional estimation techniques can badly fall and be strongly biased. It is known that EEG can be easily affected by artifacts. So we suggest a robust estimation technique which considerably performs well against those artifacts.

• Journal of Korea Multimedia Society
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• v.21 no.1
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• pp.1-9
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• 2018

Much research has been conducted to judge aesthetic value for a single type of stimuli, but research to determine aesthetic value when two kinds of stimuli are presented at the same time is not explored in depth. In this paper, we measure the difference between the presentation of visual stimuli like general image and the presentation of signboard image including text stimuli using EEG. In the experiment, two oddball tasks were performed for general images and signboard images, and EEG changes according to the aesthetic value of the images were measured. As a result, the change of ERP in signboard image was larger than that of general image. We confirmed that more visual information was received and processed when two stimuli were presented at the same time.

• Journal of the Korean Institute of Telematics and Electronics
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• v.19 no.4
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• pp.31-37
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• 1982

A microcomputerized biomedical signal processing system has been designed and fabricated. Softwares for this system have also been developed to record and analyze ECG and EEG waveforms. In this systenm, the vectorcardiogram of ECG waveforms is formed automatically and displayed on CRT with of her usefull cardiac information. The frequency components of EEG waveform can also be analyzed in this system and the analyzed spectrum is displayed on CRT.

• Proceedings of the Korean Society of Computer Information Conference
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• 2020.07a
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• pp.467-468
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• 2020

현재 많은 곳에서 생체신호를 이용하여 보다 쾌적한 삶의 환경을 구축하려는 연구가 활발하게 진행되고 있으며 뇌-컴퓨터 인터페이스(Brain-Computer Interface, BCI)기술은 미래 손꼽히는 기술 중 하나로 보고 있다. 본 논문에서는 기존에 웹사이트나 애플리케이션으로 나와 있는 윷놀이 게임을 뇌전도(Electroencephologram, EEG)를 이용한 상호작용을 바탕으로 한 윷놀이 게임의 개발에 대해 기술하고 있다. 이 게임을 통해 마비 환자나 부득이하게 손을 사용하지 못하는 경우에도 게임을 진행할 수 있으며, 뇌신경 운동에도 도움이 될 것으로 기대하고 있다.