• 전기학회논문지
• /
• 제57권6호
• /
• pp.1109-1115
• /
• 2008

In the ubiquitous health monitoring environments, it is quite important not only to evaluate the physiological health condition but also mental stress condition. In order to achieve this goal, a heart activity monitoring system utilizing a wearable bipolar electrode is devised and the heart rate variability(HRV) is extracted and interpreted in both frequency and time feature domains. Consequently, to evaluate the emotional stress condition of the subjects, a stress-induced experimental protocol was applied to healthy subjects and the time and frequency features of heart activity were analyzed in terms of the ratio of low frequency components v.s., high frequency components and the relevant the moving average distributions compromising the successive RR peaks intervals in the ambulatory ECG measurement system.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
• /
• pp.380.1-380.1
• /
• 2016

In this study, we report a novel antioxidant ZnO nanoparticle that is newly designed and prepared by simple surface modification process. Antioxidative functionality is provided by the immobilization of antioxidant of 3,4,5-trihydroxybenzoic acid (galic acid, GA) onto the surface of ZnO nanoparticles. Microstructure and physical properties of the ZnO@GA nanoparticles were investigated by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), infrared spectroscopy (IR) and steady state spectroscopic methods. The antioxidative activity of ZnO@GA was also evaluated using ABTS (3-ethylbenzothiazoline-6-sulfonic acid) radical cation decolorization assay. Notably, ZnO@GA showed strong antioxidative activity in spite of the conjugation process of GA on the ZnO surface. These results provide that GA-coating onto ZnO nanoparticles may offer an intriguing potential for biomedical devices as well as nanomaterials.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2002년도 ITC-CSCC -2
• /
• pp.1023-1026
• /
• 2002

In this paper, we propose an efficient transcoding of MPEG video. Transcoding is the process of converting a compressed video format to another different compressed video format. We propose an simple and efficient transcoding by requantization in which MPEG coded video at high bit-rate is converted into MPEG bitstream at lower bit-rate. To reduce a image quality degradation, we use HVS(Human Visual System) that is the effect that visibility of noise is less in high activity regions than in low activity regions. By using the effect, the part of image in high activity region is coarsely quantized without seriously degrading the image quality. Experimental results show that the proposed method can provide good performance.

• 전기학회논문지
• /
• 제57권12호
• /
• pp.2336-2344
• /
• 2008

In this paper, muscular activity and muscle fatigue of FDI(first dorsal interosseous muscle) and thenar muscle of hand was analyzed with surface EMG signal based on four kinds of attitudes(grip, tip, key and palmar) to measure grip strength and pinch strength after hand operation and rehabilitation treatment. The normative data are needed to interpret evaluation data to assess a patient's ability to return to labor environment. The preceding researchers proposed the standard data only by studying on maximum grip strength and the maximum pinch strength followed by each attitude of subjects' hands. But in this study, the muscle activity and muscle fatigue were considered under the various attitude to propose normative data. As a results, the muscle fatigue may be used only for presentation of normative data in labor environment.

• 대한전기학회논문지:전력기술부문A
• /
• 제48권4호
• /
• pp.478-485
• /
• 1999

The purpose of this paper was the determination of the relationship between the chaotic charateristics and various levels of brain activities. Assuming that EEG(eletroencephalogram), which is generated by a nonlinear electiecal behavior of billions of neurons in the brain, has chaotic characteristics, it was confirmed by frequency spectrum analysis, log frequency spectrum analysis, correlation dimension analysis and Lyapunov exponents analysis. Chaotic characteristics are related to the degree of brain activity. The slope of log frequency spectrum increased and the correlation dimension decreased with respect to the brain activities, while the lagrest Lyapunov exponent has some rough correlation.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
• /
• pp.1175-1178
• /
• 2004

On-line partial discharge(PD) monitoring system has been developed to monitor in operating large motor stator insulations. This system makes use of remote diagnosis techniques for the evaluation of PD activity in the control center of thermal power plant. This system can be remotely accessed via a modem to build database, analyze status and interpret the pattern of PD activity. A personnel computer is generally connected to ten motors to continuous measurement of the PD activity. The test data can be easily interpreted by a maintenance staff. For assessing the condition of stator winding in motors, this system ensures a reliable measurement and accurate estimation. Capacitive couplers used for on-line PD measurement have been 80pF. The maximum PD magnitude(Qmax), PD pattern and normalized quantity number(NQN) were performed by this system.

• 한국전기전자재료학회논문지
• /
• 제32권2호
• /
• pp.161-164
• /
• 2019

This study describes the development of graphene-$TiO_2$ conjugates for the enhancement of the photocatalytic efficiency of $TiO_2$. Graphene-based hybrid nanomaterials have attracted considerable attention because of the unique and advantageous properties of graphene. In the proposed hybrid nanomaterial, graphene serves as an electron acceptor to ensure fast charge transfer. Effective charge separation can, therefore, be achieved to slow down electron-hole recombination. This results in an enhancement of the photocatalytic activity of $TiO_2$. In addition, increased adsorption and interactions with the adsorbed reagents also lead to an improvement in the photocatalytic activity of graphene-$TiO_2$ hybrid nanomaterials. The acquired result is encouraging in that the photocatalytic activity of $TiO_2$ was initiated using visible light (630 nm) instead of the typical UV light.

• 한방재활의학과학회지
• /
• 제21권3호
• /
• pp.13-20
• /
• 2011

Objectives : We studied the clinical utility of meridian electromyography for the assessment of erector spinae muscle in functional leg length inequality. Methods : We compared electrical activity between A group with a functional leg length inequality(n=17) and B group(n=23) in dynamic flexion-reextension state during five minutes. We anayzed amplitudes and areas of electrical activity and asymmetry index(AI). Results : 1. The short leg sides were significantly higher electrical activity than the long leg sides in the experimental group and control group(p<0.05). 2. The AI of A group significantly higher than B group(p<0.05). Conclusions : According to above results, there are correlations between erector spinae muscle and functional leg length inequality.

• 국제물리치료학회지
• /
• 제11권1호
• /
• pp.2012-2020
• /
• 2020

Background: Multifaceted approaches will be needed, such as global synkinesis (GS) achieve functional improvements in the arms of stroke patients from involuntary movements during exercise. Objective: To identify changes in arm GS and muscle activity, functional evaluation and the correlation with variables through action observation training, combined with functional electrical stimulation (FES), thereby verifying the effect on stroke patients. Design: A quasi-experimental study. Methods: The subjects of this study were 20 stroke patients who were divided into two groups: Control group (n=10) and experimental group (n=10). Before the intervention, arm GS and muscle activity were measured using surface electromyography (EMG), and arm function was evaluated using the Fugl-Meyer Assessment (FMA) scale. At the end of the intervention, which lasted 4-wk, arm GS and muscle activity were measured again using the same scale. Results: There was a decrease statistically significant difference in GS during the bending action in experimental group (P<.01). Both groups showed a significant difference increased only in the activity of the anterior deltoid (AD) and biceps brachii (BB) (P<.05). The results of the arm functional assessment revealed a significant difference increase in both groups (P<.05). In the between-group comparison, there was a significant difference decrease in GS during the bending action (P<.05). Only the muscle activity of the AD and BB were significantly increase different (P<.05). There was a significant between-group difference increase in the arm functional assessment (P<.05). There was a positive correlation between GS and muscle activity on the FMA in the control group (r=.678, P<.05). In experimental group, GS during the bending arm action exhibited a negative correlation (r=-.749, P<.05), and the muscle activity of the AD and BB showed a positive correlation (r=.701, P<.05). Furthermore, in experimental group, the activity of the extensor carpi radialis increased, and the activity of the flexor carpi radialis decreased, which exhibited a negative correlation (r=-.708, P<.05). Conclusion: These results suggest that brain plasticity could be more efficiently stimulated by combining surface stimulation in the affected arm of stroke patients.

• The Journal of Korean Physical Therapy
• /
• 제29권2호
• /
• pp.45-49
• /
• 2017

Purpose: This study was conducted to determine the effects of sling exercise on muscle activity and pain in patients with rotator cuff repair. Methods: This research evaluated 20 rotator cuff repair patients, divided randomly between 10 controls and 10 in an experimental group who performed a sling exercise. Both the experimental and control groups underwent transcutaneous electrical nerve stimulation and performed continuous passive motion. Muscle activity was measured with a surface electromyograph and pain was measured with the visual analogue scale. The paired t-test was used to compare groups before and after the experiment. The independent t-test was conducted to assess differences in the degree of change between the two groups before and after the experiment. Results: Within-group comparison of both the experimental and control group showed significant differences in muscle activity and pain. Comparison of the groups revealed significant differences in muscle activity between groups group, but not in pain. Conclusion: These results indicate that sling exercise is effective for improving muscle activity of rotator cuff repair patients.