• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.5
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• pp.976-981
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• 2009

This paper proposed optimal design and microcontroller driver for driving the thin-type ultrasonic motor. To find the optimal size of the stator, motions of the motor were simulated using ATILA by changing length, width and thickness of the ceramics. Two sinusoidal waves which have 90 degree phase difference were needed for driving the thin-type motor. The thin-type ultrasonic motor driver was composed of microcontroller(Atmega128), push-pull inverter, encoder and AD-converter. Microcontroller generates four square waves which have variable frequency and 25[%] duty ratio in $20{\sim}150$[kHz]. The output signals of microcontroller were converted to sine wave and cosine wave by push-pull inverter and were applied to the thin-type ultrasonic motor. The encoder and AD-converter were used for maintaining speed of the thin-type ultrasonic motor. The AD-converter controlled DC voltage of inverter in accordance with output signal of encoder. Using the driver, characteristics of the motor as speed and torque were measured.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1999.11a
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• pp.189-194
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• 1999

This paper proposes a current-fed type high frequency inverter using a soft switching technology Zero-Voltage-Switching to reduce turn on and off loss at the switching. The analysis of the proposed circuit was described by using normalized parameter and operating characteristics have been evaluated as to switching frequency and parameters. The theoretical results are in good agreement with the experimental ones. In the future the proposed circuit is considered to be useful for induction heating applications.

• Proceedings of the KIPE Conference
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• 2013.11a
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• pp.29-30
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• 2013

본 논문에서는 수중통신용 Parametric Array Transducer를 구동하기 위한 고효율 전력증폭기를 제안한다. 수중전력증폭기는 증폭부와 전원부로 나뉘며 증폭부는 Class B push-pull type의 전력증폭기를 사용하며 전력증폭기 구동을 위한 전원부는 기존의 일정전압이 아닌 가변전압을 얻는 Phase-shifted PWM AC/DC 컨버터를 사용하여 고효율로 동작한다. 증폭부는 Class B push-pull type 증폭기를 사용함으로써 뛰어난 선형성이 보장되며 전원 또한 ET(Envelope Tracking)기술을 적용한 가변전압 AC/DC컨버터를 사용하여 고효율로 동작한다. 본 논문에서는 고 효율 수중전력증폭기와 가변전압 AC/DC컨버터의 전력회로를 제시하고 시뮬레이션과 실험을 통하여 특성을 확인하였으며, 수중음향센서를 위한 전력증폭기로 유용하게 사용 될 것을 예상한다.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.364-367
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• 2000

This paper describes a Push-Pull type high fre-quency resonant inverter conposed of consolidation of boost converter circuit and resonant circuit. By using a boost converter circuit the proposed inverter can obtain a twice input voltage of reson ant circuit and reduce a secondary turn ratios. By using both boost-converter and switching device can be reduce by half. Also the ana-lysis of the proposed circuit was described by using normalized parameter and operating characteristics have been evaluated as to switching frequency and parameters. In the future this pro-posed inverter shows that it can be practically used as a power source system for the lighting equipment of discharge lamp induction heating applications.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.3
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• pp.401-406
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• 2012

The aim of this research is to develop more actual high-frequency power generators that includes various noise, to make flexible control systems for test or performance analysis of electric and electronic machines. It proposed power generating circuits using basic amplifier, B-level Push-Pull type, and FPGA for the easier control to get data and transmit. And it also testify to realize the proposed systems to report output data by input waveform and designed the digital LPF with MATLAB, universal simulation tools, for this study.

• Transactions of the Korean hydrogen and new energy society
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• v.19 no.5
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• pp.417-422
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• 2008

In this paper, a novel DC/DC low-voltage high-current converter circuit is proposed to improve the efficiency of power converter used in the grid-connected fuel-cell generator system. We proposed a novel high efficiency grid-connected power conditioning system for RPG fuel cell. On the result of that, the loss of system was decreased rapidly by driving stack within the condition of maximum efficiency. The peak currents of the current-type inductor and the transformer's coil are reduced by synchronizing switching frequency of Buck-type converter is increased twice as the Push-Pull converter's switching frequency. The novel structure of DC/DC converter is able to realize ZVS-ZCS in fuel-cell system is proposed. The proposed switching component of Push-Pull converter has the ZVS and ZCS function by using the circuit of new passive clamp.

• IE interfaces
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• v.10 no.3
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• pp.209-216
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• 1997

This mixed push and pull production system defines that all stages are not ordered by either of the production systems. Some stages are ordered by a push-type production system and the other stages are ordered by a pull-type production system. A decision support system is built by using a combination of optimization program and the "tunable" SIMAN discrete-event simulation for the implementation of an optimally mixed production system. Finding this optimal system requires 6 CPU hours for the case study on a Pentium. Both the simulation and optimization model are validated with a case study of Phoenix company that manufactures transmitters. This paper uses survey from experts in this company for evaluation and validation of this system.

• Journal of Biomedical Engineering Research
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• v.38 no.4
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• pp.143-152
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• 2017

The main purpose of this research was to examine the EMG characteristics of driver's upper limb and driving performance for operating accelerator and brake pedal by using four types of left hand control devices(Push/Pull, Push/Right angle, Push/Rock, Push/Twist) during simulated driving. The persons with disabilities in the lower extremity have problems in operation of the vehicle because of functional impairments for controlling accelerator and brake pedal. Therefore, if hand control device is used for adaptive driving controls in persons with lower extremity loss, the disabled people could improve their quality of mobility life by driving a car. Twenty subjects were involved in this research to assess driving performance and EMG activities for operating accelerator and brake pedal by using four types of left hand controls in driving simulator. We measured EMG responses of six muscles(posterior deltoid, middle deltoid, biceps, triceps, extensor carpi radialis, and flexor carpi radialis) during pulling and pushing movement with four types of left hand controls for acceleration and braking. STISim Drive 3 program was used for evaluation test of four types of left hand control devices in straight lane course for time to reach target speed and brake reaction time. While operating the four types of left hand controls for acceleration, EMG activities of posterior deltoid in normal subjects were significantly increased(p < 0.05) compared to the disabled subjects. It was also found that EMG responses of triceps and posterior deltoid were significantly increased(p < 0.05) when using the Push/Right angle type than Push/Pull type. While operating the four types of left hand controls for braking, EMG activities of flexor carpi radialis and triceps in subjects with disability were significantly increased(p < 0.05) compared to the normal subjects. It was shown that muscle responses of posterior deltoid, middle deltoid and triceps were significantly increased when using the Push/Right angle type than Push/Rock type. Time to reach target speed and brake reaction time in subjects with disability was increased by 2.5% and 4.6% on average compared to normal subjects. The person with disabilities showed a tendency to relatively slow performance in acceleration at the straight lane course.

• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.6
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• pp.577-583
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• 2004

Optimal parameters were selected to design an inverter circuit that drives a cold cathode fluorescent lamp for LCD backlight using a piezoelectric transformer and it was verified by an experiment. In this paper, the applied inverter topologies are a push-pull type and a half-bridge type, and the dimming control methods of these drive system were used a analog control method and a burst control method each other. When change a control voltage from 2.5V to 4.5V in the analog control method, the brightness 0-100% was seen in current 1-6 mA. And, the input/output efficiency were obtained 90.3%. Also, the control performance of 1-6 mA was seen in duty ratio 5-50% in the burst control method, and the input/output efficiency of the designed inverter got 82.1%.

• IE interfaces
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• v.13 no.3
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• pp.348-357
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• 2000

SCM(Supply Chain Management) is a new approach to satisfy customers via an integrated management for the whole business processes of the manufacturing from the raw material procurement to the product or service delivery to customers. Typically the semiconductor industry is the one whose supply chain network is distributed all over the world, and its manufacturing process has the particular characteristics which has to be considered in the modeling of supply chain. In this paper we suggest the push and pull type supply chain models based on the manufacturing characteristics and their mathematical formulation for the semiconductor industry. Push supply chain model pursuits the high throughput and the balance of the WIP flow, and pull supply chain model does to minimize the total cost of order-based manufacturing, distribution and transportation process in order to meet customer's request appropriately.