• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.12
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• pp.157-163
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• 2008

In the multi-phase interleaved converter with peak current mode control, current imbalance is measured when inductors of converter module are not exactly identical. In this paper current-sharing controller is proposed to balance phase current of converter modules. It also is designed to have good transient response. Proposed method implemented the 2-phase and 4-phase interleaved boost converter with imbalanced inductance. Experimental results verify the performance of Current share during the transient state of converter.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1998.04a
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• pp.165-170
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• 1998

The purpose of this study was to develop a program for analysis of eye movement on balance. Gain, phase and symmetry in eye movement were calculated automatically by softwere algorithm with C. It was concluded the algorithm established in this study will improve accuracy in evaluating balance function.

• Polymer(Korea)
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• v.25 no.6
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• pp.855-865
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• 2001

The optimization condition of injection molding for a commercial product of TV speaker grille of A Company was induced using a CAE software of Moldflow. The flow and packing phase analysis was performed by using flow balance, runner balance, and the intermediate one by using the above two balances, which were used for controlling the amount of packing resins into the cavity, Later, the analysis performed by using the measured viscosity (local database) at various shear rates and the results were compared with the computer simulation using the standard database. Flow balance induced minimized weld line resulted in a better appearance and physical properties of the were line, but exhibited a disadvantage of large deformation and gas formation due to over-packing of the molten resin in the center of the speaker grille. Runner balance improved the disadvantage of the flow balance by controlling the amount of molten resin injected from the gate, however resulted reduced mechanical properties and poor appearance of the weld line. However, the modified method induced from the flow and runner balance improved the disadvantages by changing the runner size. In addition, the analyses based on the local database and the standard database were compared. Although the measured viscosity was slightly higher and the temperature distribution was broader than the standard database, no distinct difference was obtained from the analysis using the two different databases.

• Journal of the Korean Society of Physical Medicine
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• v.18 no.2
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• pp.1-11
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• 2023

PURPOSE: This study examined the immediate effects of applying ankle eversion taping using kinesiology tape in chronic stroke patients-design: a randomized cross-over trial. METHODS: Seventeen stroke patients underwent three interventions in random order. The subjects were initially assigned randomly to an ankle eversion taping, placebo taping, or no taping for each intervention. Ankle eversion taping was used for mechanical correction and was involved in ankle dorsiflexion and eversion. The tape was stretched by 30-40%. Placebo tapping was applied in the same form as eversion tapping but was not stretched. The balance ability was assessed using the Y-balance test. The gait ability was assessed by maximum foot pressure and time of stance phase, and gait speed was assessed using a 10 m walk test (10MWT). All measurements were performed immediately after the intervention. RESULTS: The results showed that the dynamic balance and stance phase time in chronic stroke patients was improved after ankle eversion taping. The ankle eversion taping conditions increased significantly (p < .05) compared to the placebo and no taping conditions. CONCLUSION: The application of ankle eversion taping that uses kinesiology tape instantly increased the gait ability of chronic stroke patients. On the other hand, more research will be needed to identify the long-term effects of ankle eversion taping.

• Journal of the Korea Institute of Military Science and Technology
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• v.3 no.2
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• pp.81-87
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• 2000

This paper presents an application of forced oscillation technique to measure pitch dynamic stability derivatives of a missile model in the low speed wind tunnel. The missile model is oscillated by D.C. electric servomotor with constant amplitudes and frequencies. Phase shift is determined as the difference of peak values between input and output signals from the dynamic stability balance installed at the center of gravity of the model. Stability derivatives were calculated by using phase shifts, amplitudes, forcing moments and input frequencies. Test results show the proper usage of the force oscillation technique with good damping effects.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.50 no.3
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• pp.101-108
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• 2001

Frequency is an important operating parameter of a power system. Electric power systems sustain transient frequency swings whenever the balance between generation and load does not no longer hold. To cope with this constraints, it requires an accurate and high speedy frequency deviation estimation technique and suitable adjustment to obtain the Power system energy balance. This paper describes a digital signal processing technique for measuring the operating frequency of a power system. The fundamental frequency component of 3-phase signal is first extracted by using an algorithm based on FIR filter. The rate change of the phase angle is used for estimation. To confirm the validity of the proposed algorithm, the simulation studies carried out on a typical 154KV double T/L system by using EMTP software. Some test results are presented in the paper.

• Journal of Power Electronics
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• v.12 no.5
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• pp.739-747
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• 2012

This paper applies carrier phase shifted pulse-width modulation (CPS-PWM) to transformerless modular multilevel converters (MMC) to improve the output spectrum. Because the MMC topology is characterized by the double-star connection of six legs consisting of cascaded modular chopper cells with floating capacitors, the balance control of the DC-link capacitor voltage is essential for safe operation. This paper presents a leg-balancing control strategy to achieve DC-link voltage balance under all operating conditions. This strategy based on circulating current decoupling control focused on DC-link balancing between the upper and lower legs in each phase pair by considering the six legs as three independent phase-pairs. Experiments are implemented on a 100-V 3-kVA downscaled prototype. The experimental results show that the proposed leg-balancing control is both effective and practical.

• Journal of The Korean Society of Integrative Medicine
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• v.5 no.4
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• pp.21-30
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• 2017

Purpose : This research intends to identify the effects of game-based weight bearing exercises on balance, muscular activation, sit to stand to sit motions of stroke patients. Method : 30 patients who were diagnosed as hemiplegia by stroke less in than a year were sampled and they were classified into two group, one of which was game-based weight bearing balance exercise group, and the other was functional weight bearing exercise group. 15 people were randomly selected for each group. Each exercise was coordinated by this research for 8 weeks, 5 days a week. 3D motion analyzer was used to measure the sit to stand to sit motions and a stopwatch was used to measure the time for stand-up motions for 5 times. Result : In terms of analyzing sit to stand to sit motions by phases, game-based weight bearing balance exercise group showed significant reduction compared to functional weight-bearing exercise group in phase I, II, III, IV and total time. In terms of functional stand-up performance analysis, game-based weight bearing balance exercise group showed significant reduction compared to functional weight-bearing exercise group in 5 times stand-up examination. Conclusion : It was verified that game-based weight bearing balance exercise had positive impact on function recovery of stroke patients by enhancing sit to stand to sit capabilities. It is considered that game-based exercise was an effective intermediary for functional improvement of stroke patients, while also inducing consistent and voluntary participation by causing interest and motivation.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.23 no.1
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• pp.63-72
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• 2017

Background: The purpose of this case study was to investigate into the effect of complex exercise program on the postural change, gait and balance ability in elementary school students with forward head posture. Methods: Four patients with forward head posture were recruited. They were evaluated pre-treatment, and after 6weeks, using neck disability index (NDI), numeric pain rating scale (NPRS), balance ability, foot pressure (fore foot/rear foot peak pressure ratio, F/R ratio), gait ability (cadence, toe out angle, stance phase). Results: First, the angle of forward head posture (craniovertebral angle; CVA and cranialrotation angle; CRA) was decreased in all subjects. The NPRS and NDI were decreased in all subjects. Also, The cadence, toe out angle and F/R ratio were increased in all subjects. The stance phase of gait cycle was positively change in all subjects. Lastly, the static balance ability improved in all subjects. Conclusion: According to the results above, the complex exercise program for students with forward head posture can help improve the postural change, gait and balance ability. Also, the complex exercise program was able to select interventions depending on the patient's condition and the desired goal.

• Journal of Power Electronics
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• v.16 no.6
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• pp.2109-2118
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• 2016

Based on the space vector pulse width modulation (SVPWM) theory, this paper realizes an easier SVPWM strategy, which is equivalently implemented by CBSPWM with zero-sequence voltage injection. The traditional SVPWM strategy has no effect on controlling the neutral-point voltage balance. In order to solve the neutral-point voltage unbalance problem for neutral-point-clamped (NPC) three-level inverters, this paper proposes a neutral-point voltage balance controller. The proposed controller realizes controlling the neutral-point voltage balance by dynamically calculating the offset superimposed to the three-phase modulation waves of an equivalent SVPWM strategy. Compared with the traditional SVPWM strategy, the proposed neutral-point voltage balance controller has a strong ability to balance the neutral-point voltage, has good steady-state performance, improves the output waveforms quality and is easy for digital implementation. An experiment has been carried out on a NPC three-level inverter prototype based on a digital signal processor-complex programmable logic device (DSP-CPLD). The obtained experimental results verify the effectiveness of the proposed neutral-point voltage balance controller.