• 대한인간공학회지
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• 제29권1호
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• pp.47-53
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• 2010

An analysis of biosignal and performance data collected during driving has increasingly employed in research to explore a human-vehicle interface design for better safety and comfort. The present study developed a protocol and a system to effectively analyze biosignal and driving performance measurements in various driving conditions. Electrocardiogram (ECG), respiration rate (RR), and skin conductance level (SCL) were selected for biosignal analysis in the study. A data processing and analysis protocol was established based on a comprehensive review of related literature. Then, the established analysis protocol was implemented to a computerized system so that immense data of biosignal and driving performance can be analyzed with ease, efficiency, and effectiveness for an individual and/or a group of individuals of interest. The developed analysis system would be of use to examine the effects of driving conditions to cognitive workload and driving performance.

• 대한인간공학회지
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• 제29권1호
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• pp.113-120
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• 2010

This research is to evaluate the arousal level by using cardiovascular response. PPG was used in this study as one of the method of measuring it rather than ECG (Electrocardiography) for the purpose of solving ergonomic problem of sensing. The participants were in the age group of 20 (mean=24, standard deviation=1.25): five men and five women. Each experiment composed with four identical sets. First, a black screen was displayed for 30 second rest. Then, the prepared 6 pair images were randomly presented for 10 second stimulation and for 30 second non-stimulation. PPG was measured on the earlobes of experimenters at 200Hz sampling frequency. PPG amplitude, PPI(Pulse to Pulse Interval), and PRV(Pulse Rate Variability) were analyzed according to arousal level. T-test was performed to compare between the PPG variables of rest and relaxation, rest and arousal, and relaxation and arousal. Relative to the rest state, PPG amplitude decreased in relaxed state and increased in aroused state. Relative to the rest state, PPI decreased in both emotional states. However, more significant decline was observed in aroused state. PRV's LF and HF were used in the form of LF/HF to compare between the relaxed and the aroused state. Therefore, PPG signal showed significant differences between relaxed and aroused state. In conclusion, evaluation of human arousal level used in the PPG analysis demonstrated that PPG has better usability and comforter measurement than ECG and is clearly an alternative method of measuring arousal level.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 V
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• pp.2745-2748
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• 2003

In this paper, we implement the photoplethysmo-graphy system that have three channel pulse wave detects and one channel ECG amplifier. In order to detect the artery state, we measured the pulse waves at different positions, simultaneously. In general, arterial vascular system suffers the decrease of compliance, increase of resistance, and decrease of distensibility through aging. Therefore, we compared and analyzed variation of tile Pulse waves parameter both in time and frequency domains that is concerned with the changes of arterial characteries. And then evaluated the correlation coefficients between the parameters variation and the age group. As the result of experiment, we found that the Parameters have a significant correlation about aging.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.935-939
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• 2003

The emotion recognition is one of the most significant interface technologies which make the high level of human-machine communication possible. The central nervous system stimulated by emotional stimuli affects the autonomous nervous system like a heart, blood vessel, endocrine organs, and so on. Therefore bio-signals like HRV, ECG and EEG can reflect one' emotional state. This study investigates the correlation between emotional states and bio-signals to realize the emotion recognition. This study also covers classification of human emotional states, selection of the effective bio-signal and signal processing. The experimental results presented in this paper show possibility of the emotion recognition.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1993년도 춘계학술대회
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• pp.63-65
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• 1993

We have done a preliminary study on the detection of ventricular late potentials using high-resolution electrocardiography. We designed a battery powered low-noise ECG amplifier. We used the XYZ lead system and the amplifier provides 3 channels of X, Y, and Z signals with a conventional gain and another 3 channels of the amplitude-limited X, Y, and Z signals with high-gain. 12-bit data acquisition system interfaces the amplifiers to a personal computer for further signal analysis. Beat alignment algorithm was implemented on the low-gain signals to synchronize the signal averaging of the high-gain amplitude-limited signals. We suggest the use of the weighted vector sum of X', Y', and Z' signals based on the SNR of each channel. We speculate that this new method will increase the accuracy of the LP detector at the expense of more complicated hardware.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 추계학술대회
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• pp.443-446
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• 1997

HRV(heart rate variability) is the time series data of R-R interval time duration based on ECGs. Power spectral analysis of HRV has recently been used to define the activity of ANS(autonomic nervous system). In this study, 14 rats were divided into two groups, sympathectomy and vagotomy. During the experiments, ECGs of rats were collected three times at each experimental conditions or the duration of 5 minutes, where sampling frequency was set at 2KHz. After the application of the Berger's Serires algorithm to ECG raw data, power spectrum of HRV was obtained via FFT. Results showed that HF/LF were increased or the sympathectomy group and decreased or the vagotomy group. It implies that the variations in HF/LF components could be used or the ANS function classification.

• 한국감성과학회:학술대회논문집
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• 한국감성과학회 2002년도 춘계학술대회 논문집
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• pp.186-189
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• 2002

The footwear such as socks and shoes is the clothing which are necessary to our life. In this study, clothing comfort of the footwear was carried out by physiological responses and subjective evaluation. As a result, the effect to walking comfort by the height of a heel in female shoes became clear. Then suitability evaluation system of shoes was proposed from the measuring results. On the other hands, the clothing comfort of the hosiery was evaluated from ECG analysis. By this analysis, it became clear that the factor which influences the clothing comfort of the hosiery was the clothes pressure in the hosiery. In the future, plane shape of the foot and solid shape must be considered in order to design the hosiery.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 D
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• pp.2693-2695
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• 2002

In this paper, the power spectral analysis of heart rate variability(HRV) was performed to evaluate effects of orthostatic stress with head-up tilt on autonomic nervous system(ANS) for 20 healthy male subjects(age : 245 yr.) and a new method was proposed to assess the autonomic balance. The ECG signals wore recorded for 3 minutes in both the supine and 70 head-up tilt positions, and then the HRV signals underwent power spectrum analysis at each position. The results of this study suggest that cardiac autonomic functions, such as sympathetic tone in autonomic balance with the increment of sympathetic tone and the decrement of parasympathetic tone which occur during head-up tilt position, arc not sufficient to overcome tile orthostatic stress arising in Cerebral Palsy.

• 한국자동차공학회논문집
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• 제17권4호
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• pp.16-23
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• 2009

Driving simulators are useful tools not only to test the components of future cars but also to evaluate the telematics service and HMI (Human-Machine Interface). However driving simulators cannot be implemented to test and evaluate the telematics service system because the GPS (Global Positioning System) which contains basic functional support for the telematics module do not work in the VR (virtual reality) environment. This paper presents a method to implement telematics service to a driving simulator by developing the GPS simulator which is able to emulate GPS satellite signals consist of NMEA-0183 protocol and RS232C communication standards. It is expected that the driving simulator with the GPS simulator can be used to study HMI and human-factor evaluations of the commercial telematics system to realize the HiLES (Human-in-the-Loop Evaluation System).

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 춘계학술대회
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• pp.176-178
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• 1997

We are exposed to the various types of external stimuli, and many researches have been conducted to analyze the emotional changes to the stimuli quantitatively. In this paper, changes of human emotion was studied by analyzing HRV from ECG signals which were varied by the auditory stimulus. Power contents for each frequency bands were calculated from HRV waveforms. Two peak values representing autonomic nervous system status, HF and LF, were used to extract the parameters. An analysis on the normalized HF/LF to the subjective rating of the subject were performed. It was assumed that the positive emotional changes evoked by the auditory stimuli, the HF values representing activation of the parasympathetic nervous system, are increased much higher than the LF values, activation of the sympathetic nervous system. Results showed that the parasympathetic nervous system works more actively than the sympathetic nervous system to the stimuli which cause the positive emotional changes.