• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.1
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• pp.29-38
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• 2023

Although the biosignal is the best way to represent the human condition, it is difficult to acquire the biosignal of a driver driving for detecting driver's condition. As one of the methods to overcome this limitation, this paper proposes a driving stress monitoring system based on information provided by OBD-II(on-board diagnostics version II). The driving information and EDA(Electrodermal activity) data are obtained through the OBD-II scanner and E4 wristband, respectively. EDA data is used as ground truth to distinguish whether driver is stressed or not. MLP(multi-layer perceptron) neural network is used as a model to detect driving stress and is trained using driving data for about a month. To evaluate the proposed system, we used about 1 hour of driving data and the accuracy is 92%.

• The Journal of Korean Academy of Sensory Integration
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• v.9 no.1
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• pp.45-52
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• 2011

Objective : The aim of this study was to provide the method to measure physiologic response using equipments and auditory stimulation, and the physiologic response features of adult psychiatric disorders through a systemic review. Methods : The systemic review was executed using PubMed. The key words for search were "auditory stimulation, auditory startle, electromyograph, skin conductance, heart rate, psychiatric disorder, anxiety disorder, schizophrenia, depression". 8 studies were used for data analysis, and all of levels of evidence were level II. The substances of the review were subject(population), auditory stimulation, measure equipments and physiologic response features of psychiatric disorder. Results : 1. The subjects for the studies were anxiety disorder(4) and schizophrenia(4). 2. Auditory stimulation was used in 8 studies and visual stimulation with auditory stimulation was used in 2 studies to induce physiologic response. 3. Every study used electromyograph, and skin conductance was used in 2 studies and heart rate was used in 2 studies with electromyograph to measure physiologic response. 4. The subjects for the studies, schizophrenia and anxiety disorder(PTSD, OCD) have different physiologic response features with the normal control group. Conclusion : All studies used simple tones as an auditory stimulation and electromyograph to measure physiologic response. Psychiatric disorders indicated larger response, shorter and delayed habituation. The objective and systematic study using physiologic measure to investigate the sensory feature of psychologic disorders.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.43 no.3 s.309
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• pp.60-66
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• 2006

The purpose of this study was to suggest a new detection method for early diagnosing diabetic neuropathic foot by obtaining a ratio of toe to finger blood flow using photoplethysmography(PPG) and Laser Doppler(LD). Nerve conduction velocity (NCV) has been routinely used for diagnosing neuropathic foot, but it applies strong electric stimulus to peripheries resulting in stress and pain. The blood flow ratio of 50 neuropathic diabetes($0.96{\pm}0.20$) was significantly higher than that of 64 normal person($0.46{\pm}0.15$)(p<0.000). It also showed that toe temperature of neuropathic diabetes($30.5{\pm}1.4^{\circ}C$) was significantly higher than that of normal group($29.3{\pm}2.0^{\circ}C$)(p<0.000). The optimal boundary value of the blood flow ratio was found to be 0.678 and the sensitivity and specificity of this proposed method resulted in 95.3% and 95.3% respectively. Lastly, there were no neuropathic diabetes whose temperature difference between finger and toe was higher than $4.5\;^{\circ}C$.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.34 no.1
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• pp.9-13
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• 2011

The purpose of this study was to investigate the effects of the secondary tasks such as sending text message (STM) and searching navigation (SN) on skin conductance level (SCL) and deviation of vehicle speed during driving. The participants included 30 healthy adults; 14 males aged $25.2{\pm}0.9$ with $1.9{\pm}1.8$ years of driving experiences and 16 females aged $22.6{\pm}1.9$ with $1.2{\pm}0.8$ years of driving experiences. All subjects were instructed to keep a constant speed (80km/h or 100km/h). SCL and deviation of vehicle speed were measured during driving only and driving with secondary tasks. SCL and deviation of vehicle speed were more increased during the driving with secondary tasks than driving only. Secondary tasks increased an activation of sympathetic nerve system and decreased driving performance. However, there were no significant differences in the SCL and deviation of vehicle speed according to gender and speed.

• Science of Emotion and Sensibility
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• v.10 no.2
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• pp.263-271
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• 2007

A review of recent studies indicates that positive emotions help buffer stress. In particular, humor is what only human can appreciate. Humor plays an important role in many facets of human life including psychological, social, and somatic functioning. This study is to identify children's ANS responses by humor or joy using audio-visual film clips. 49 male and female children (12-13 years) participated in this study. The participants were briefed on the experiment was its procedure. During the experiment, electrodes were attached to participant and middle fingers of left hands. Physiological responses(EDA, SKT, PPG and ECG) were measured for 30s both in the resting state and experiment state during which emotion provoking stimulus was presented for 2 min. Also, self-report on emotions was followed for 1 min. Results from the self-report showed that both humor and joy were evoked effectively among 89.3% of children. It explains that emotion-eliciting stimuli were effective and appropriate. ANS responses in both emotion were significant in three physiological variables (i.e., SCL, NSCR, LF). There was a significant difference between humor emotion and joy emotion, and both emotions were distinguishable by a specific ANS response pattern.

• Sleep Medicine and Psychophysiology
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• v.9 no.1
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• pp.61-67
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• 2002

Objectives: This study is aimed at measuring psychophysiological responses using a biofeedback system in healthy people to obtain basic normative data for biofeedback research and treatment. Methods: Ninety-six healthy volunteers (55 males and 41 females : average age $30.4{\pm}8.0$) without any history of major medical or psychiatric illnesses participated in this study. Psychophysiological responses were assessed using the ProComp+ and BioGraph program (ver. 2.1) with regard to forearm and frontal electromyography (EMG), electrodermal response (EDR), and skin temperature. They were measured in 3 phases (baseline, stress, and recovery phases), respectively. Beck depression inventory and Spielberger state and trait anxiety inventory were used to measure mood states. We compared psychophysiological responses according to age and gender differences, respectively and examined the relationship between mood states and psychophysiological measures. Results: People in their twenties showed higher EDR levels in the 3 phases than those of other age groups. Female subjects showed higher frontal EMG levels in the 3 phases compared with male subjects. There was no significant correlation between biofeedback measures and mood states in these subjects. Conclusion: We present normative data of psychophysiological responses measured by a biofeedback system in healthy people. These results suggest that gender and age should be considered as important variables in assessing psychophysiological responses using a biofeedback system.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.42 no.6
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• pp.67-76
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• 2005

This paper proposes a compact-sized surface myoelectric sensor for the myoelectric hand prosthesis. To fit the surface myoelectric sensor in the socket for the myoelectric hand prosthesis, the sensor should be a compact size. The surface myoelectric sensor is. composed of a skin interface and a single processing circuit that are mounted on a single package. The skin interface has one reference and two input electrodes, and the reference electrode is located in the center of two input electrodes. In this paper we propose two types of sensors with the circle- and bar-shaped reference electrode, but all input electrodes are the bar-shaped. The metal material of the electrodes is the stainless steel (SUS440) that endures sweat and wet conditions. Considering the conduction velocity and the median frequency of the myoelectric signal, we select the inter-electrode distance (IED) between two input electrodes as 18mm, 20mm, and 22 mm. The signal processing circuit consists of a differential amplifier with a band pass filter, a band rejection filter for rejecting 60Hz power-line noise, amplifiers, and a mean absolute value circuit. We evaluate the proposed sensor from the output characteristics according to the IED and the shape of the reference electrode. From the experimental results we show the surface myoelectric sensor with the 18mm IED and the bar-shaped reference electrode is suitable for the myoelectric hand prosthesis.

• Journal of the Ergonomics Society of Korea
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• v.29 no.6
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• pp.869-874
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• 2010

The purpose of this study was to analyze the skin conductance level (SCL) induced by unexpected situation which reflected the emotional and cognitional responses during driving. The participants included 57 college graduates; 28 males aged $24.5{\pm}1.3$ with $2.3{\pm}1.5$ years of driving experiences and 29 females aged $23.6{\pm}2.6$ with $2.2{\pm}1.7$ years of driving experience. Reaction time of brake, averaged SCL, maximum SCL, and rising time to maximum amplitude were measured. They were analysed according to condition (crash, non-crash) and gender (male, female). The reaction time of brake was more faster and averaged SCL was greater during non-crash condition than during crash condition. There were no significant differences between male and female drivers in the reaction time of brake and averaged SCL whether or not it crash. There were no significant differences between crash and non-crash conditions in the maximum SCL and rising time to maximum amplitude, but there were significant differences between male and female in them. These results support the hypothesis that averaged SCL is more related to cognitional response and maximum SCL and rising time to maximum amplitude are more related to emotional responses.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.2
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• pp.147-151
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• 2004

This study aims at measuring electrical and rheological properties of cosmetic emulsions on the skin under shear flow. The effects of volume ratio and surfactants on structural changes of emulsions were examined by determining the changes of electrical resistance, viscosity, and morphology. As the ratio of the internal phase increased, the phase inversion occurred more quickly. The viscosity change was found to increase with increasing of the variation of electrical resistance of the emulsions. This phenomenon may be caused by decreased resistant force against the shear flow because of the breakdown of the internal phase. Surfactants a]so played a key ro]e on phase transition of emulsions. It is likely that polymeric surfactants anchoring on the emulsion surface reinforced the interfacial mechanical strength. As the concentration of surfactants increased, the phase transition occurred more slowly. It has been demonstrated that the phase changes of emulsions under shear flow can be monitored on the real-time basis by using a JELLI$\^$TM/ chip system, a combination of conductiometry and rheometry. Our approach is expected to a useful experimental tool for predicting the phase transition of the cosmetic products during skin application.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.31-35
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• 2003

폴리카보네이트는 내열성과 투명성이 우수한데 비해 내후성이 좋지 않아 황변 및 물성이 저하되고, 내찰상성이 약하여 긁히기 쉬운데다 이물질에 의해 오염되기 쉬워 투명성이 저하되는 문제점이 있다. 이러한 단점을 극복하고, 사용하는 용도에 따라 요구되는 다양한 기능성을 부여하기 위하여 폴리카보네이트 표면에 기능성층을 형성시킴으로써 그 목적을 달성하고자 한다. 본 논문에서는 이온 주입기술을 이용하여, 폴리카보네이트 표면의 전기전도도 특성을 향상시키고, 피부암 및 백내장 등을 유발하는 유해한 자외선 (UV-A, UV-B)을 차단하려 한다. 표면전기전도도의 향상은 이물질로부터 오염되는 정도를 낮추며, 정전기를 방지할 수 있다. PC(Polycarbonate) 표면에 $N^+,\;Ar^+,\;Kr^+,\;Xe^+$ 이온을 에너지 20keV에서 50keV을 사용하여, 주입량 $5{\times}10^{15}\;{\sim}\7{\times}10^{16}\cm^2$ 로 조사하였다. 이온 주입된 PC의 표면을 두 접점 방법의 표면 저항 측정으로 표면전기전도도 특성을 알아보았고, 자외선차단 특성은 UV-Vis 로 분석하였다. 이들 전기적 광학적 특성간의 상관관계를 관찰하고, 이러한 특성을 나타내는 화학적 기능그룹들의 변화를 보기 위해 FTIR 분석법으로 관찰하였다. 이온조사량의 증가에 따라 표면저항은 $10^7{\Omega}/sq$까지 감소하여 표면전기특성을 증가시키며, 자외선 차단 특성은 UV-A를 95%까지 차단하여 인체에 유해한 자외선 차단에 유용함을 확인하였다. 이러한 특성은 PC 표면에 카본 네트워크 형성과 $\pi$전자들의 운동량을 증가시키는 구조로 고분자 사슬들의 결합구조 변형에 의한 것으로 생각된다.블을 가지고 파서를 설계하였다. 파서의 출력으로 AST가 생성되면 번역기는 AST를 탐색하면서 의미적으로 동등한 MSIL 코드를 생성하도록 시스템을 컴파일러 기법을 이용하여 모듈별로 구성하였다.적용하였다.n rate compared with conventional face recognition algorithms. 아니라 실내에서도 발생하고 있었다. 정량한 8개 화합물 각각과 총 휘발성 유기화합물의 스피어만 상관계수는 벤젠을 제외하고는 모두 유의하였다. 이중 톨루엔과 크실렌은 총 휘발성 유기화합물과 좋은 상관성 (톨루엔 0.76, 크실렌, 0.87)을 나타내었다. 이 연구는 톨루엔과 크실렌이 총 휘발성 유기화합물의 좋은 지표를 사용될 있고, 톨루엔, 에틸벤젠, 크실렌 등 많은 휘발성 유기화합물의 발생원은 실외뿐 아니라 실내에도 있음을 나타내고 있다.>10)의 $[^{18}F]F_2$를 얻었다. 결론: $^{18}O(p,n)^{18}F$ 핵반응을 이용하여 친전자성 방사성동위원소 $[^{18}F]F_2$를 생산하였다. 표적 챔버는 알루미늄으로 제작하였으며 본 연구에서 연구된 $[^{18}F]F_2$가스는 친핵성 치환반응으로 방사성동위원소를 도입하기 어려운 다양한 방사성의 약품개발에 유용하게 이용될 수 있을 것이다.었으나 움직임 보정 후 영상을 이용하여 비교한 경우, 결합능 변화가 선조체 영역에서 국한되어 나타나며 그 유의성이 움직임 보정 전에 비하여 낮음을 알 수 있었다. 결론: 뇌활성화 과제 수행시에 동반되는 피험자의 머리 움직임에 의하여 도파민 유리가 과대평가되었으며 이는 이 연구에서 제안한 영상정합을 이용한 움직임 보정기법에 의해서 개선되었다. 답이 없는 문제, 문제 만들기, 일반화가 가능한 문제 등으