• Journal of Korean Physical Therapy Science
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• v.11 no.4
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• pp.20-28
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• 2004

The studys purpose were the effects of work posture, treatment method and prevention for Video Display Terminal(VDT) workers in Work-Related Musculoskeletal Disorders(WMSD) The results were as follows: 1. The prevalence rate of VDT workers in WMSD was $20{\sim}40%$. The complaint was mostly shoulder, neck, and hack area pain 2. VDT worker used to forward flexed posture and then affect of increase of muscle fatigue and pain 3. When exercise therapy PT and ADL training, were used workers decrease in pain, muscle strength, balance training, endurance strength and relief of psychiatricIn conclusion, VDT worker need good health and posture to rest and exercise with time space and treatment. It is best to prevent WMSD. VDT workers need health management by itself and systemic rehabilitation program by speciality therapist.

• Journal of Satellite, Information and Communications
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• v.10 no.2
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• pp.70-74
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• 2015

In this paper, satellite communication based video surveillance system that consisted of ultra-small aperture terminals with small-size smart vision sensor is proposed. The events such as forest fire, smoke, intruder movement are detected automatically in field and false alarms are minimized by using intelligent and high-reliable video analysis algorithms. The smart vision sensor is necessary to achieve high-confidence, high hardware endurance, seamless communication and easy maintenance requirements. To satisfy these requirements, real-time digital signal processor, camera module and satellite transceiver are integrated as a smart vision sensor-based ultra-small aperture terminal. Also, high-performance video analysis and image coding algorithms are embedded. The video analysis functions and performances were verified and confirmed practicality through computer simulation and vision sensor prototype test.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.54-57
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• 2002

In this study, a new programming method, to minimize the generation of Si-SiO$_2$ interface traps of scaled SONOS flash memory as a function of number of program/erase cycles has been proposed. In the proposed programming method, power supply voltage is applied to the gate, forward biased program voltage is applied to the source and the drain, while the substrate is left open, so that the program is achieved by Modified Fowler-Nordheim (MFN) tunneling of electron through the tunnel oxide over source and drain region. For the channel erase, erase voltage is applied to the gate, power supply voltage is applied to the substrate, and the source and drain are open. A single power supply operation of 3 V and a high endurance of 1${\times}$10$\^$6/ prograss/erase cycles can be realized by the proposed programming method. The asymmetric mode in which the program voltage is higher than the erase voltage, is more efficient than symmetric mode in order to minimize the degradation characteristics of scaled SONOS devices because electrical stress applied to the Si-SiO$_2$ interface is reduced by short programming time.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.122-122
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• 2010

A Static Induction Thyristor (SI-Thyristor) has a great potential as power semiconductor switch for pulsed power or high voltage applications with fast turn-on switching time and high switching stress endurance (di/dt, dV/dt). However, due to direct commutation between gate driver and SI-Thyristor, it is difficult to design optimal gate driver at the aspect of impedance matching for fast gate current driving into internal SI-Thyristor. Thus, to penetrate fast positive gate current into steady off state of the SI-Thyristor, it is proposed and proceeded the internal impedance calculation of the SI-Thyristor at steady off state with the gate driver while switching conditions that are indicated applied gate voltage, $V_{GK}$ and applied high voltage across anode and cathode, $V_{AK}$.

• Physical Therapy Korea
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• v.15 no.3
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• pp.17-25
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• 2008

This study aimed to evaluate the effect of a weekly circuit-group exercise program on functional performance, flexibility of the trunk and lower extremities, and balance in individuals with chronic stroke who are living in a community. Thirteen community-living individuals (eleven males and two females) with chronic stroke participated in this study. The group exercise program was set up as a weekly circuit application with four stations aiming to strengthen the muscles, increase endurance, improve flexibility, and enhance functional capacity. The average duration of a session was an hour, and the sessions were conducted once a week for six months for a total of 24 sessions. Assessments for functional performance, flexibility of the trunk and lower extremities and balance were conducted four times: before treatment, after one month of treatment, after four months of treatment, and after six months of treatment. There were significant improvements in functional performance and flexibility of the trunk and lower extremities in the given time frame. No significant improvement was observed in balance ability. The findings suggest that a weekly circuit-group exercise program has some benefits in terms of managing the physical symptoms of individuals with mobility problems after stroke. Therefore, this program can be adapted and employed as a community-based rehabilitation program for such patients. Further studies with various community-based treatments will be conducted to validate these findings.

• Journal of the Korea Institute of Building Construction
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• v.4 no.3
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• pp.83-91
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• 2004

With labor shortage and high-wage era, the construction cost is rising and the construction business is dull, demanding the construction environment of Korea to raise profitability through major cost savings and rationalization of construction management. However, although reinforcing bar(rebar) work, which greatly effects the building's safety, endurance, and construction time, is an important phase in construction, it holds serious problem of quality and productivity deterioration due to its characteristic of intensive-labor and maintaining of old work methods resulting in poor management, and costs increase. Therefor in this study to investigate current situation and problems of rebar work and to find methods of betterment, a survey was conducted to site engineers and individuals in division of cost estimate of domestic construction company. The survey questions were on the subjects of (1) calculating rebar quantity, (2) ordering and procurement, (3) rebar cutting and bending, and (4) rebar work management. Method of improvement was sought by analyzing the results of the survey

• The Journal of Korean Physical Therapy
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• v.14 no.3
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• pp.373-406
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• 2002

This study was peformed to investigate the effects on skeletal muscle recovery with aqua-exercise; swimming to take the muscle endurance for 20 days on two group of white rats which were the low extremity atrophy group(control groups) by fixed for two weeks and aqua-exercise group(experimental groups) after it. The effects was observed with light and electron microcope to measure the morphological changes of muscle fibers. The results obtained were as follow. 1. Light microscope: In the case of control groups, quadriceps fibers had been irregular alignment, decreased muscle width and the irregular alignment nuclear appeared, as it is degenerative muscle fibers. In the case of experimental groups, the fibers had been regular alignment cells and fibers. The nucleus of muscle had been normal characterized by oval shape and fiber sarcomere clearly classified. 2. Electron microscope: In the case of control groups, there were the quadriceps which was Z-line streaming phenomenon induced at the sarcomere and cells nuclear separated from basal membrane. It was not only observed the sarcomere alignment irregularly and mitochondria damaged, but also vacuoles found. In the case of experimental groups, A band, I band, H band had been clearly appeared, classified at the myofibrils of quadriceps, and electronic dense M-line found in sarcomere. There were observed satellite cells and basal laminas that usually to be appeared at the time of mitochondrial development, skeletal muscle fiber regeneration or development. This results suggest that the aqua-exercise assisted to inhibit the degenerative morphological changes of skeletal muscle cells and help to recover from abnormal states. Especially, it is considered to effect on a normal structural formation.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.47 no.3
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• pp.55-62
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• 2015

Paper mulberry fibers have been used as fibrous raw materials for manufacturing traditional handmade paper, hanji for a long time. Compared to wood pulp fibers, pulp fibers from mulberry bast tissue have some benefits in physical and chemical properties due to their high D.P (degree of polymerization), M.W (molecule weight) and long fiber length. Specially, Korean handmade hanji shows outstanding characteristics in mechanical tensile strength, folding endurance, flexibility and long sustainable conservation properties. Therefore, hanji is widely applied to daily supplies, hygienic goods, medical supplies, clothing industries and so on. Recently, the potential demand of mulberry pulp fibers is more and more increased on the strength of high application fields. This study was focused on the possibility of wastewater recycling in unit operation systems for the development of automated mass production line. The properties and environmental loads of wastewater from debarking, cooking, bleaching and screening process were analyzed by means of COD, conductivity, turbidity and solid materials. The wastewater from debarking and cooking process was comparatively high in pollution load, and would be treated by additional approaches of chemico-physical method.

• Laser Solutions
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• v.12 no.4
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• pp.12-16
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• 2009

The engineering ceramic is one of the materials advantageous in various conditions with high strength, endurance at high temperature, abrasion resistance and corrosion resistance, etc. However, due to high strength and high brittleness, ceramic incurs high costs and long time on finishing process required after sintering. So a process for obtaining wanted measurements of them has been studied using the high temperature which makes ceramics softened and heat affected recently. This study makes an estimate of laser-assisted machining (LAM) if an economically practical process for manufacturing precision silicon nitride ceramic parts using laser beam. In this study, mechanical properties of silicon nitride at high temperature were observed. And during the LAM, it was observed that cutting force and tool wear were reduced and oxidation of machined surface was increased according to a increase of laser power.

• The Journal of Korean Physical Therapy
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• v.19 no.3
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• pp.11-17
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• 2007

Purpose: The purpose of this study were to analyze fatigue patterns of the rectus femoris muscle by isometric contraction. Methods: Twenty healthy subjects(10 male, 10 female) participated in this study. Maximal voluntary isometric contraction(MVIC) was measured by the dynamometer. Muscle activity was recorded from the rectus femoris muscle. During the experiment, the subject was seated in the chair. The measured items, median frequency(MDF) and root mean square (RMS), were collected from the surface EMG. All data were analyzed using repeated measures ANOVA. Results: There was significant difference of MVIC between male and female. Endurance time was significant difference by the level of MVIC but no significant in the main effect(sex) and interaction effect. The MDF and fatigue index were significant differences in the interaction effect. The RMS was not significant difference in both of main and interaction effect. The muscle fatigue patterns of female was greater than male after 60% MVIC. Conclusion: This study showed that sex differences of muscle fatigue were started from 60% MVIC.