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Abstract:The construction of Pohang Accelerator Laboratory X-ray Free-Electron Laser (PAL-XFEL), a 0

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This study presents a new carrier-based hybrid pulse width modulation (PWM) Method for the cascaded capacitorclamp multilevel inverter (CCCMLI), which combines the benefits of a new alternative level-shifted carrier PWM and a phase-shifted carrier PWM. For modulating the CCCMLI, the phase disposition sub-harmonic PWM was first proposed, but does not show good performances in an even load sharing between inverter cells connected in series, flying-capacitor voltage balancing and output waveform quality. On the other hand, a proposed PWM method enables to achieve a balanced load sharing between cascaded cells even at low amplitude modulation indices as well as the excellent voltage balancing control of the flying-capacitors with a much smaller voltage ripple and the good harmonic characteristics in output waveforms. The proposed modulation is verified through both simulation and field-programmable gate array (FPGA) based experimental results.

PURPOSE:The purpose of this study was to analyze the effect and examine the feasibility of an intervention of ankle strategy exercise on balance of patients with hemiplegia. METHODS:The subject were randomly allocated to three groups: ankle strategy exercise (group A), balance exercise (group B) and control (group C).Group A was received the conventional physical therapy plus ankle strategy exercises for 20 minutes in one session. Group B was received the same conventional physical therapy plus balance exercises for 20 minutes in one session. Two active groups were performed in the session 3 times a week, for a total of 6 weeks. and Group C was only received the same conventional physical therapy.Balance test was assessed using center of pressure (COP) in the anteroposterior (A-P), mediolateral (M-L) direction, Berg balance scale (BBS) and Timed Up and Go Test (TUG).

-Speed sensorless modes of operation are becoming standard solution in the area of electric drives. This paper presents flux estimator and speed estimator for the speed sensorless vector control of induction motors. The proposed sensorless methods are based on the model reference adaptive system (MRAS) observer and adaptive speed observer (ASO). The proposed speed estimation algorithm can be employed in the power control of grid connected induction generator for wind power applications. Two proposed schemes are verified through computer simulation PSIM and compared their simulation results.

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