• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 A
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• pp.221-223
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• 1997

This paper deals with the slip power recovery system using switch mode converter in the inverter DC side, which recovers slip power of induction machine to AC line with the aid of the boost converter. As a results, the motor speed can be controlled by the duty ratio of boost switch, not by inverter firing angle. This results that the reactive power produced by phase controlled inverter and diode rectifier can be greatly reduced and linear speed regulation can be obtained. Moreover, the harmonic components of line current caused by the commutation in inverter and rectifier can be considerably suppressed. Therefore, most of the problems in conventional system can be solved.

• Journal of Electrical Engineering and Technology
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• 제8권4호
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• pp.911-919
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• 2013

This paper reports the development of test bed with the energy recovering technique using two-step boost converter. The device is utilized for LDC aging test of Hyundai Motor's LPI AVANTE HEV in mass production. The developed power recycle type test bed is designed as 1.5 kW class to test up to the maximum load power of LDC and is also designed to supply scant power supply up to 500 W after power recycle. The theoretical design analysis and operational characteristics analysis results of test bed are reported, and its practicality and reliability are verified through the test result. Also, the finally developed test bed confirms approximately 79~85 % energy saving effect compared to the usual traditional aging test system.

• 한국산학기술학회논문지
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• 제17권7호
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• pp.459-466
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• 2016

본 연구는 아급성기 뇌졸중 환자에서 로봇 보조치료법이 운동능력 및 기능적인 회복에 미치는 효과를 알아보고자 하였다. 환자 53명이 연구에 참여하였다. 로봇보조 보행치료군은 고식적인 치료에 추가로 Lokomat$^{(R)}$ 이용하여 하루에 삼십분씩, 일주일에 5회, 4주 동안 시행하였으며, 대조군은 고식적인 치료에 추가로 하루에 삼십분씩 고식적인 치료를 시행 받았다. 모든 환자들은 임상지표의 비교를 위해, 치료 전과 4주간의 치료 후 Fugl-Meyer assessment, Motricity index, functional ambulation category, Berg balance scale, 10m 보행검사, 한국판 수정 바델지수, 한국판 간이 정신 상태검사와 벡 우울증 척도를 평가 받았다. 환자들은 기능회복과 체성 감각 유발전위 검사 결과의 관계를 알아보기 위해 유발 전위 검사를 시행하였다. 아급성기 뇌졸중 환자에서 로봇 보조 보행치료군에서 대조군에 비해 하지의 운동기능, 보행 능력, 일상생활능력의 유의한 호전이 나타났다. 체성 감각 유발 전위 검사의 결과는 임상 지표들의 관련성 분석에서 Motricity index와 한국판 수정 바델지수와 관련이 있는 것으로 나타나 아급성기 뇌졸중 환자의 기능을 예측하는데 유용할 것으로 생각된다. 로봇 보조 보행치료는 아급성기 뇌졸중 환자의 운동기능과 보행기능의 회복을 촉진하는 것으로 생각된다.

• 대한임상전기생리학회지
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• 제6권1호
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• pp.1-15
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• 2008

This study was designed to investigate the effect of treadmill exercise of low-intensity and high-intensity on the functional recovery and histological change in spinal cord injury rats. Sprague-Dawley rats were experimented(n=15) for this research. Spinal cord injury was induced by the NYU drop impacter device after laminectomy. After operation, rats were test at modified Tarlov scale at 3 days, and divided into the control group(n=5), experimental group I(n=5, low-intensity treadmill) and experimental group II(n=5, high-intensity treadmill). The rats were disciplined from 7 day through 21 day. Functional recovery was evaluated by the BBB scales and the Grid Walk test for the progressive locomotor recovery at 3, 7, 14, 21 days. Histopathological studies for the muscle in order to observation the change of damage and size of the organized surface which is visible visually it executed hematoxylin & eosin stain. According to the result of 4 weeks of treadmill exercise, group II showed improvement than group I of motor behavior after spinal cord injury.

• 대한물리치료과학회지
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• 제9권2호
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• pp.7-16
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• 2002

This study was conducted to assess the changes in the functional levels of affected upper extremities after treating hemiplegic patients by applying constraint-induced movement therapy(CIMT). The subjects were selected from 20 hemiplegic patients with scores of 25 or more in Mini Mental State Examination(MMSE-k), transferred to the departments of physical therapy in two university hospitals in Busan from December, 2001 to march, 2002, and were divided into two groups. Eleven subjects with fixing unaffected arms by CIMT were assigned to the experimental patient group and the other 9 patients to control group without fixing unaffected arms. The function of upper arms for both groups were evaluated by using Actual Amount of Use Test(AAUT) and Motor Active Log(MAL) before and after physical therapy. The malts were as follows: The recovery rates of upper extremity by AOU(Activity of Use) and QOM(Quality of Movement) were 23.9% and 27.3% for CIMT treated group, and by 8.3% and 4.6% for the control group on the average, respectively, in AAUT after physical therapy, showing statistically significant differences between two groups. And in MAL, the average recovery rates were 27.3% by AOU and 22.6% by QOM for CIMT treated group while 3.1% by both AOU and QOM for the control group, and were significantly different between twogroups.

• 조명전기설비학회논문지
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• 제21권7호
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• pp.117-123
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• 2007

제조업에서 생산설비에 사용되는 중요한 에너지원 중 하나는 전력에너지이며, 에너지 다소비 업종의 생산설비 즉, 플랜트에서는 사용하는 에너지의 절감과 효율 운전은 매우 중요한 관심사항이다. 본 논문에서는 생산 플랜트의 한 공정에서 가장 빈번히 사용되는 유도전동기를 모델로 하여 실제 진단, 계측을 통하여 측정값을 얻고, 기존의 운전 중인 설비들을 고효율 기기로 교체하였을 경우의 경제성을 분석하였다. 이를 위해서 현재 운전 중인 설비와 고효율설비로 교체하였을 경우에 대하여 각각 설비들의 연간 운전비용과 자본회수계수에 의한 연간 투자비용을 계산하였고, 이를 합산한 연간 총 운용비용을 비교하여 고효율설비의 경제적 타당성을 입증하였다.

• 설비공학논문집
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• 제25권10호
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• pp.529-533
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• 2013

Heat-recovery ventilators are being adopted in most newly built apartment houses for energy reduction and indoor environment improvement. In winter, however, the dew condensation resulting from the difference between the indoor and outdoor temperatures may reduce the ventilator's performance and threaten the health of indoor residents. This study analyzes the occurrence of dew condensation according to the ventilator's operational conditions and the changes of temperature and products. The experimental results show that condensations is formed at $26^{\circ}C$ and 60%R.H, which is an unfavorable climatic condition, and when the damper is not closed tightly. Therefore it is important to ensure damper performance to prevent back flow.

• 전기학회논문지
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• 제67권9호
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• pp.1159-1164
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• 2018

Vacuum circuit breakers(VCB) are widely used for current interruption of high-voltage inductive loads such as induction motors. This VCB can be chopped off before the current zero due to its high arc-extinguishing capability. One of the outstanding features of VCB is that it can cut off high frequency re-ignition current more than other circuit breakers. If the transient recovery voltage generated in the arc extinguishing is higher than the dielectric strength of the circuit breaker, a re-ignition phenomenon occurs. The surge voltage of the re-ignition is very high in magnitude and the steepness of the waveform is so severe that it can act as a high electrical stress on the winding. If the high frequency current of one phase affects the other two phases when the re-ignition occurs, it may cause a high surge voltage due to the virtual current chopping. If the magnitude of the voltage allowed in the motor winding is high or the waveform level is too severe, it may lead to insulation breakdown. Therefore, it is necessary to reduce the voltage to within a certain range. In this study, we briefly explain the various phenomena at the time of interruption, analyzed the magnitude of the dielectric strength and the transient recovery voltage at the simultaneous three-phase interruption that can give the greatest influence to the inductive load, proposed a method to reduce the impact.

• 동의생리병리학회지
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• 제25권2호
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• pp.257-263
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• 2011

This study was designed to investigate the effects of Hominis placenta pharmacopuncture treatment and electroacupuncture therapy on the functional recovery and histological change, protein expression in spinal cord injury(SCI) rats. Experimental groups were divided into the Group I(normal control rat), Group II(Non-treatment after spinal cord injury induction), Group III(Hominis placenta pharmacopuncture treatment after SCI induction), Group IV (Electroacupuncture therapy after SCI induction), Group V(Hominis placenta pharmacopuncture treatment and electroacupuncture therapy after SCI induction). After operation, rats were tested at modified Tarlov test at 1 to 3 days with divided into 4 groups, and motor behavior test(BBB locomotor rating scale, Grid walk test) was examined at 3, 7, 14, and 21 days. For the observation of damage change and size of the organized surface in muscle and spinal cord, histopathological studies were performed at 21 days by H & E stain, and BDNF & NT-3 protein expression studies were performed at 21 days. Acco rding to the results, Hominis placenta pharmacopuncture treatment and electroacupuncture therapy can play a role in facilitating recovery of locomotion following spinal cord injury. Specially, Hominis placenta pharmacopuncture treatment and electroacupuncture combimed therapy after SCI induction was most improvement in functional recovery, BDNF, and NT-3 protein synthesis.

• 설비공학논문집
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• 제20권6호
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• pp.372-380
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• 2008

In order to control indoor air quality and save energy, it is needed to install a suitable ventilation system equipped with heat exchanger for heat recovery. Paper heat exchanger can recover $50{\sim}70%$ of the enthalpy difference between supply and exhaust air. The purpose of this research is to obtain the experimental correlations for the friction factor, heat transfer coefficient, mass transfer coefficient and permeance of paper heat exchanger, which can be used to predict the performance of the paper heat exchanger. Pressure drops at various velocities, and sensible and latent heat transfer rates at various dry-bulb temperatures, relative humidities and specific humidities are measured to derive experimental correlations. The results of prediction using correlations show fairly good agreement with the experimental data obtained in the actual operating conditions.