• Tribology and Lubricants
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• v.15 no.2
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• pp.164-170
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• 1999

Gerotor is widely used as a hydraulic pump or motor, by virtue of its volume changing ability. Performance deterioration of a gerotor hydraulic motor mainly due to the wear come from the contact between inner rotor with trochoidal curve and outer rotor with circular arc profile. This research covers the basic investigation about the contact forces of a gerotor hydraulic motor using analytic method. The influence of the eccentricity and the radius of circular arc teeth on the contact stress was evaluated.

• International Journal of Control, Automation, and Systems
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• v.2 no.3
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• pp.279-288
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• 2004

This paper presents a novel design for a tubular linear brushless permanent-magnet motor. In this design, the magnets in the moving part are oriented in an NS-NS―SN-SN fashion which leads to higher magnetic force near the like-pole region. An analytical methodology to calculate the motor force and to size the actuator was developed. The linear motor is operated in conjunction with a position sensor, three power amplifiers, and a controller to form a complete solution for controlled precision actuation. Real-time digital controllers enhanced the dynamic performance of the motor, and gain scheduling reduced the effects of a nonlinear dead band. In its current state, the motor has a rise time of 30 ms, a settling time of 60 ms, and 25% overshoot to a 5-mm step command. The motor has a maximum speed of 1.5 m/s and acceleration up to 10 g. It has a 10-cm travel range and 26-N maximum pull-out force. The compact size of the motor suggests it could be used in robotic applications requiring moderate force and precision, such as robotic-gripper positioning or actuation. The moving part of the motor can extend significantly beyond its fixed support base. This reaching ability makes it useful in applications requiring a small, direct-drive actuator, which is required to extend into a spatially constrained environment.

• Journal of Wellbeing Management and Applied Psychology
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• v.5 no.2
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• pp.29-32
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• 2022

Purpose: The purpose of this study is to observe the immediate effects of elastic taping and isometric exercises on balance ability in the elderly. Research design, data and methodology: 15 elderlies were participated in this study and randomly assigned into two group. The intervention group was applied elastic taping on ankle joint while the control group performed isometric ankle exercise in three sets for 30 seconds per set. Anterior-posterior and medial-lateral postural sway speed were measured after the experiment. To compare the change in balance ability between groups after the experiment, independent t-test was used. To investigate the change in balance ability between pre- and post-experiment within the groups, paired t-test was used. Results: A significant difference in medial-lateral postural sway speed was found after elastic taping application only in the intervention group (p>0.05). However, there was no significant difference between the groups. Conclusions: In conclusion, this finding supported that elastic taping would be helpful to support ankle stability and increase balance ability for the elderly as well as performance for sports athlete that was demonstrated in previous studies. Further studies will be necessary to confirm the long-term effects of elastic taping application on motor control and the risk of falling.

• Journal of the Korean Academy of Clinical Electrophysiology
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• v.8 no.1
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• pp.7-13
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• 2010

Purpose : This study was performed as follows in order to investigate the effect of presynaptic inhibition mechanism using the transcutaneous electrical stimulation (TES) for global synkinesis (GS) on the post-stroke hemiplegic patients. Methods : The subjects consist of 38 post stroke hemiplegic patients; experiments were performed on thirty patients excluding eight. The experiment was performed on sham group, sensory level stimulation group, and motor level stimulation group for 20 minutes a day 5 times a week for 6 weeks total. We compared the differences in GS levels and walking ability. The measurements were carried out pre, immediated, post 10th, and 20th, for a total of four measurements. Results : The GS level using sEMG found significant differences between groups at the post 10th and post 20th in dorsiflexion, and post 20th in plantarflexion (p<0.05, p<0.01). The motor level group indicated more significant differences when the number of electrical stimulations increased. TUG and 10 m walking test indicated a significant difference at immediated, post 10th, and post 20th. The motor level group showed more significant decreasing tendency than the sensory level group. Conclusion: From these results, electrical stimulation using presynaptic inhibition mechanism of transcutaneous electrical stimulation (TES) had positive effects for walking ability on inhibition of muscle tone in lower extremity. The motor level stimulation group experienced a more significant effect than the sensory level stimulation group. Therefore, the transcutaneous electrical stimulation (TES) is considered to be effective on walking ability increasing through inhibition of muscle tone in lower extremity for rehabilitation of post stroke hemiplegic patients.

• The Journal of Korean Academy of Sensory Integration
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• v.15 no.1
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• pp.10-20
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• 2017

Objective : The purpose of this study was to investigate the effect of proprioceptive-vestibular based sensory integrative intervention on handwriting and fine motor function in elementary school students in grades 1 to 3. Methods : In this study, eight students in an elementary school in Busan were enrolled. The intervention was conducted twice a week from May to October, 2016, and a total of 14 intervention sessions were conducted. In order to evaluate the writing ability and the fine-motor exercise ability before and after the intervention, the fine-motor movement items of the Korean alphabet writing test and the Bruininks-Oseretsky Test of Motor Proficiency (BOTMP) evaluation were used. Results : There was a statistically significant difference between the total scores of consonant writing and the Korean alphabet writing assessment after the intervention. In BOTMP-Fine motor, the response speed items showed statistically significant difference. Visual-motor control scores increased during intervention, but the statistical significance was not found. Conclusion : Sensory integration interventions might have positive effects on elementary school students' writing skills and fine motor functions.

• Journal of The Korean Society of Integrative Medicine
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• v.2 no.4
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• pp.91-100
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• 2014

Purpose : The purpose of this experiment is to find out the effectiveness which exert influence on cognitive skills by using the Driver Rehabilitation program for senior citizens who are over 65 years old and live in Busan. Method : From July first, 2014 to August 28th, 2014, we researched the 60 elderly people who are over 65 and go to community relief center which is in Busan. - 30 are experimental group and the other is control group. In the experimental group, we used Nintendo wii's driving simulation program and RC Car driving program in the model road. For estimation, we used MVPT-3(Motor-Free Visual Perception Test-3), Trail Making Test - 1, Trail making Test - 2 and LOTCA(Loewenstein Occupational Therapy Cognitive Assessment). Result : Nintendo wii's driving simulation program and RC Car driving program in model road results efficient visual perception ability. This programs results effectively in visual perception ability and space perception ability. This programs results effectively in motor apraxia ability. This programs results effectively in control ability for visual perception. This programs results effectively in thinking operation. Conclusion : Nintendo Wii's driving simulation program and RC Car driving program in model road positively influence improving for visual perceptual ability and cognitive function of elderly people. Also it is considered as being more efficient for improving visual perceptual ability and cognitive function to implement basic rehabilitation training with driving rehabilitation program than basic training itself.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.3032-3036
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• 2011

Cooling type of traction motor for EMU in domestic is mostly an open type. Its system is a cooling air entered through air inlet cool down a traction motor and an hot air by traction motor get out air outlet. It is easy to cool it down but hard to maintain it. To improve an ability of maintenance, a total enclosed type traction motor is already developed and used in abroad, not an opne type. So we developed a total enclosed type traction motor which will be used in domestic and abroad EMU. We tried to reduce a weight and a size compared with the abroad one. In contrast with open type traction motors which cool off inside of motors, total enclosed motors cool down by cooling exterior frame of motors. In this case, cooling fins or air fan blowing to the exterior of motors are applied. The total enclosed type traction motor developed by us have two housing to block the foreign substance into inner of a motor and have two cooling fan to easy to reduce a heat happened at a coil. In this paper, design of a cooling structure of the total enclosed traction motor developed twice and performance verification through test will be discussed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.401-406
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• 2006

This paper presents the fault diagnosis of induction motor based on support vector machine(SVMs). SVMs are well known as intelligent classifier with strong generalization ability. Application SVMs using kernel function is widely used for multi-class classification procedure. In this paper, the algorithm of SVMs will be combined with feature extraction and reduction using component analysis such as independent component analysis, principal component analysis and their kernel(KICA and KPCA). According to the result, component analysis is very useful to extract the useful features and to reduce the dimensionality of features so that the classification procedure in SVM can perform well. Moreover, this method is used to induction motor for faults detection based on vibration and current signals. The results show that this method can well classify and separate each condition of faults in induction motor based on experimental work.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.171.1-171
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• 2001

This paper describes the design and implementation of a new type of a force reflective joystick. It has single degree of freedom that is actuated by motor and brake pair. The use of motor and brake allows various objects to be simulated without the stability problem and related safety issues involved with high torque motors only. The joystick performance is measured by its ability to simulate various test objects. Simple test objects are modeled as a benchmark test of the system´s performance and to evaluate different control approaches for hybrid motor/brake actuator. The force output joystick is capable of simulating forces in a variety of virtual environments. This device demonstrates the effectiveness of a hybrid motor/brake haptic actuator.

• Journal of Institute of Control, Robotics and Systems
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• v.5 no.7
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• pp.868-875
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• 1999

In this paper, digital motor control center using protection relay is developed in order to protect power systems by means of timely fault detection and diagnosis during operation for induction motor which have various load environments and capacities in power systems. Digital motor control center is employed by power supervisory control systems without separate remote terminal unit and transducers adding communicational ability. Also we develope a maximum demand controller to control the load effectively at peak status and a power factor controller to minimize real power losses and improve the power factor. Therefore, when using the developed controller, real time computation is possible by loading DSP in hardware and applying real-time kernel which can convert each algorithm to task module.