• 전기학회논문지
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• 제63권9호
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• pp.1286-1293
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• 2014

Typically, studies through the simulation system have been progressed, because the evaluation of the driver's arousal state about the service of a actual train has risk of safety for the driver. When configured event same as the real in simulation system, the ability to cope with an accident situation may be the same each other. But the difference in the state of tension or arousal will occur. In this study, requested to cooperate with the railways in order to escape from these constraints, and the target of the experiment was to real engineer service. I was set about experiment when the train was stopped as safe as possible. As a result, the beta wave of EEG signals that representing complex calculations or anxiety is increased rapidly on the basis of a flag station from at the time of departure. The size of the electrodermal activity signal in response to movement of the body gave a noticeable. In terms of HRV, if the train approach a flag station gradually and the R-R interval is narrowed. So that the driver can be estimated as arousal state. In accordance with this study, if the quantitative standard of arousal state be based on the driver's biosignals will provide, it will be able to take advantage of development the system that would prevent train accidents caused by human error.

• 국제학술발표논문집
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• The 8th International Conference on Construction Engineering and Project Management
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• pp.257-264
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• 2020

Objective: To investigate test-retest reliability and responsiveness of Equivital Lifemonitor and photoplethysmography based wristwatch tools in assessing physiological parameters during a simulated fatigue task. Methods: Ten university students (Mean age, 30.6 ± 1.7 years) participated in this pilot study. Participants were asked to perform a 30-minute of a simulated fatigue task in an experimental setup in a lab. The physiological parameters (e.g., heart rate, heart rate variability, respiratory rate, electrodermal activity, and skin temperature) were measured at baseline and immediately after the fatigue task. An intraclass correlation coefficient (ICC2,1) was used to evaluate the test-retest reliability of each tool in assessing physiological measures. In addition, the responsiveness of each tool to measure changes from baseline to posttest was calculated using a standardized response mean. Results: The Equivital Lifemonitor has shown good to excellent test-retest reliability for the assessment of heart rate (ICC, 0.97), heart rate variability (ICC, 0.86), respiratory rate (ICC, 0.77), and local skin temperature (ICC, 0.76). However, photoplethysmography based wristwatch showed moderate to good test-retest reliability for the assessment of heart rate (ICC, 0.71), heart rate variability (ICC, 0.73), electrodermal activity (ICC, 0.80), and skin temperature (ICC, 0.72). A large standardized response mean (>0.8) indicates that both tools can capture the changes in heart rate, heart rate variability, respiratory rate, skin temperature, and electrodermal activity after a 30-minute of fatigue task. Conclusions: The Equivital Lifemonitor and photoplethysmography based wristwatch devices are reliable in measuring physiological parameters after the fatigue task. Additionally, both devices can capture the fatigue response after a simulated construction task. Future field studies with a larger sample should investigate the sensitivity and validity of these tools in measuring physiological parameters for fatigue assessment at construction sites.

• 한국감성과학회:학술대회논문집
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• 한국감성과학회 1997년도 한국감성과학회 연차학술대회논문집
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• pp.228-232
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• 1997

The special interest should be paid to the analysis of the influences of positive emotions in terms of their possible effects on the dyanmics of autonomic. recovery after the negative affective stimualtion. Taking into account emotion-specific autonomic response patterning and dissociation of parameters of autonomic arousal during experience of both positive and negative emotional states, this problem seems a challenging one. In present study several autonomic parameters were analyzed altogether, namely inedices of electrodermal activity, heart rate and respitation rate during consecutive combination or both IAPS-based visual affective and auditory stimulation. The aim of the study was analysis of patterns of electrodermal and cardiorespiratory responses during emotional states evoked by negative affective visual stimulation followed by positive or neutral auditory one with intention to identify if the latter is able to facilitate post-stress recovery and enhance restoration of pre-arousal levels. The main orientation was dirdcted towards the further application of experimentally induced comfort emotions for dampening the negative consequences of exposure to stressful stimuli.

• 음성과학
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• 제12권2호
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• pp.81-88
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• 2005

Electrodermal activity(EDA) is a bio-electric signal which occurs at the skin surface during the sweating. EDA reflects the activity of the sympathetic axis of the autonomic nervous system. EDA is associated with the eccrine sweat gland at the palmar and plamar surface. This study was aimed to characterize the relationship between EDA and auditory stimulus intensities. Acoustic stimulus used in this study were 500 Hz, 1 kHz, 2 kHz of narrow band noise, which were representative of speech frequencies in audible range. Stimulus intensity between 90 and 30 dB in 10 dB within dynamic range. After deriving the minimum stimulus intensity(threshold of skin potential) which elicited skin potential, and then the latency and amplitude were derived from waveform of skin potential, each latency and amplitude were compared to stimulus intensity. The waveform of skin potential were recorded stably, and the threshold of skin potential appeared nearly the hearing threshold level of the participant. The latency was decreased and the amplitude was increased according to the increase of the stimulus intensity. These results suggest that auditory evoked skin potential can be applicable to auditory assessment and audiological diagnosis tool.

• 한국감성과학회:학술대회논문집
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• 한국감성과학회 2000년도 춘계 학술대회 및 국제 감성공학 심포지움 논문집 Proceeding of the 2000 Spring Conference of KOSES and International Sensibility Ergonomics Symposium
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• pp.370-379
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• 2000

Autonomic responses were analyzed in 323 college students exposed to visual stimulation with Korean Affective Picture System (KAPS). Cardiac, vascular and electrodermal variables were recorded during 30 sec of viewing affective pictures. The same slides intended to elicit basic emotions (fear, anger, surprise, disgust, sadness, happiness) were presented to subjects in 2 trials with different experimental context. The first time slides were shown without any instructions (passive viewing), while during the second with instruction to exert efforts to magnify experienced emotion induced by pictures (active viewing). The aim of the study was to differentiate autonomic manifestations of emotions elicited by KAPS stimulation and to identify the role of instructed emotional engagement on physiological response profiles. The obtained results demonstrated reproducibility of responses in both trials with different contexts. Pairwise comparison of physiological responses in emotion conditions revealed the most pronounced differentiation for "ear-anger" and "fear-sadness" pairs (in electrodermal and HR variability parameters). "Fear-surprise" pair was also well differentiable. The typical response profile for all emotions included HR acceleration (except happiness and surprise), an increase of electrodermal activity, and a decrease of pulse volume. Higher cardiovascular and electrodermal reactivity to fear observed in this study, e.g., as compared to data with IAPS as stimuli, can be explained by cultural relevance and higher effectiveness of KAPS as stimuli, can be explained by cultural relevance and higher effectiveness of KAPS in producing certain emotions such as fear in Koreans.

• 한국음향학회:학술대회논문집
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• 한국음향학회 1999년도 학술발표대회 논문집 제18권 1호
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• pp.269-273
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• 1999

Combination of mental stress task with noise background is a traditional tool employed in psychophysiology. However, intensity of background noise is a factor affecting both performance on test and psychophysiological responses associated with stress evoked by mental load in noisy environment. In the current study on 7 subjects we analyzed the influence of white noise (WN) intensity (55, 70, and 85 dB[A] ) on psychophysiological responses during word recognition test performed on noise background. There were recorded following physiological variables: electrodermal activity (EDA) , namely, skin conductance level (SCL), skin conductance response (SCR) amplitude (SCR-A), rise time and total number of SCRs (N-SCR); cardiovascular activity, e.g., heart rate (HR), respiratory sinus arrhythmia (RSA) index, pulse transit time (PTT), finger pulse volume (PV), skin temperature (SKT) and respiratory activity, such as respiration rate (RESP-R) and inspiration wane amplitude (RESP-A) during baseline resting state and 40 s long performance on 3 similar Korean word recognition tests with different WN intensity (55, 70, and 85 dB). Electrodermal responses (SCR-A, SCL, N-SCR) demonstrated gradual increment with increased intensity of noise, and this increase of response magnitude with higher intensity of noise was typical also for r skin temperature (phasic SKT decrease) and pulse volume (phasic and tonic PV decrease). However, some cardiovascular and respiratory responses did not exhibit same tendency of gradual increase of reactivity , namely HR, as well as RESP-R and RESP-A showed decrement of response magnitudes. Important finding in terms of cardiovascular reactivity was that 55 and 70dB evoked similar profiles, while 85dB WN resulted in significantly different profile of reactions, suggesting that there exists a threshold level after which intensive auditory stimulation elicits psychophyslological responses pattern of different quality. There are discussed potential autonomic mechanism involved in mediation of observed physiological responses.

• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.1247-1248
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• 2022

Due to rapid urbanization and population growth, it has become crucial to analyze the various volumes and characteristics of pedestrian pathways to understand the capacity and level of service (LOS) for pathways to promote a better walking environment. Different indicators have been developed to measure pedestrian volume. The pedestrian level of service (PLOS), tailored to analyze pedestrian pathways based on the concept of the LOS in transportation in the Highway Capacity Manual, has been widely used. PLOS is a measurement concept used to assess the quality of pedestrian facilities, from grade A (best condition) to grade F (worst condition), based on the flow rate, average speed, occupied space, and other parameters. Since the original PLOS approach has been criticized for producing idealistic results, several modified versions of PLOS have also been developed. One of these modified versions is perceived PLOS, which measures the LOS for pathways by considering pedestrians' awareness levels. However, this method relies on survey-based measurements, making it difficult to continuously deploy the technique to all the pathways. To measure PLOS more quantitatively and continuously, researchers have adopted computer vision technologies to automatically assess pedestrian flows and PLOS from CCTV videos. However, there are drawbacks even with this method because CCTVs cannot be installed everywhere, e.g., in alleyways. Recently, a technique to monitor bio-signals, such as electrodermal activity (EDA), through wearable sensors that can measure physiological responses to external stimuli (e.g., when another pedestrian passes), has gained popularity. It has the potential to continuously measure perceived PLOS. In their previous experiment, the authors of this study found that there were many significant EDA responses in crowded places when other pedestrians acting as external stimuli passed by. Therefore, we hypothesized that the EDA responses would be significantly higher in places where relatively more dynamic objects pass, i.e., in crowded areas with low PLOS levels (e.g., level F). To this end, the authors conducted an experiment to confirm the validity of EDA in inferring the perceived PLOS. The EDA of the subjects was measured and analyzed while watching both the real-world and virtually created videos with different pedestrian volumes in a laboratory environment. The results showed the possibility of inferring the amount of pedestrian volume on the pathways by measuring the physiological reactions of pedestrians. Through further validation, the research outcome is expected to be used for EDA-based continuous measurement of perceived PLOS at the alley level, which will facilitate modifying the existing walking environments, e.g., constructing pathways with appropriate effective width based on pedestrian volume. Future research will examine the validity of the integrated use of EDA and acceleration signals to increase the accuracy of inferring the perceived PLOS by capturing both physiological and behavioral reactions when walking in a crowded area.

• 한국감성과학회:학술대회논문집
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• 한국감성과학회 1999년도 춘계학술발표논문집 논문집
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• pp.127-132
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• 1999

Cardiovascular, respiratory and electrodermal responses to acute stress episodes modeled by combined presentation of intense white noise and performance of word recognition task with noise background were studied in 15 college students. Experimental procedure consisted in sessions with white noise, word recognition task presentation with noise background and test with noise background. Recorded physiological variables were analyzed in terms of their sensitivity to detect activation of sympathetic and parasympathetic branches of autonomic nervous system and thus reflect autonomic arousal level during shout-term stress-inducing experimental manipulations. It was shown that performance of effortful mental task with noise background elicited significant physiological responses typical for active coping behavior, namely electrodermal arousal and increased cardiovascular activity. this response profile was more profound as compared to white noise only or attending task in noise background. However, all physiological responses were mostly phasic, without long-term tonic changes, since almost all variables recovered to their initial baseline levels, suggesting that dominant autonomic mechanisms in transient acute stress episodes were of parasympathetic nature (withdrawal in stress with subsequent activation in restoration period), while sympathetic contribution was not long-lasting. Nevertheless, increased number of stressors and their longer exposure may result in higher profile of tonic sympathetic arousal and reduced functional role of vagal mechanisms in autonomic balance regulation.

• 센서학회지
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• 제5권3호
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• pp.55-64
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• 1996

생리지표로서 각성 수준을 잘 반영하는 피부전기활동 신호로부터 피부임피던스 수준과 피부임피던스 반사 신호를 분리 검출하고 실시간으로 각성도를 판단 및 제어하는 휴대형 시스템을 구현하였다. 이를 위하여 각성도 평가 지표를 세분화하여 의식 수준을 자동적으로 판단하고 경고신호를 이용하여 각성도를 제어하는 알고리즘을 연구하여 구현된 시스템의 제어효과를 평가하고 유효성을 입증하였다. 구현된 제어 시스템은 각성도 저하의 초기 단계부터 검출하고 판정 및 제어하므로서 각성도를 향상 시킬 수 있었으며, 앞으로 각성도 향상 및 제어를 위한 경보음 등의 효과 평가와 졸음운전 방지 시스템, 수면연구 등에도 활용될 수 있으리라 기대 된다.

• 대한한의학회지
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• 제28권2호통권70호
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• pp.114-125
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• 2007

Objectives : Uterine myoma is the most common pelvic benign tumor and may cause abnormal menstrual pattern. The growth of uterine myoma depends on hormones. The 7-zone-diagnostic system (CP-6000A) is a measuring system using skin resistance variability (SRV). The machine shows organic energy and was reported by the gynecologic department to detect functional abnormality of hypothalamus-hypophysis-ovarian axis (H-P-O). Our study was to investigate the SRV of women with uterine myoma by the 7-zone diagnostic system. Methods: Two groups were selected from those who took the CP-6000A test in the College of Korean Medicine Hospital of Sangji University from March 2003 to September 2006. They were divided into normal control (n=40) and uterine myoma groups (n=40). Electrodermal activity of the two groups was compared. Results : The mean value of electrodermal activity of the uterine myoma group was lower than that of thenormal group in all areas on first and second measurement. Especially, the mean value of the patient group was significantly lower than that of the normal group and fell below normal range in the 1, 2, and 3 areas on first and second measurement. Conclusions : The results suggest that women with uterine myoma may have organic energy deficiency and functional abnormality of the H-P-O axis. Further studies to determine the feasibility of this 7 -zone diagnostic system as a reliable diagnostic tool are needed.