• Proceedings of the KIPE Conference
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• 2007.07a
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• pp.138-140
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• 2007

A novel AC-DC switching technology is suggested without inductors for one-chip semiconductor. The suggested converter consists of a rectifier diodes, AC source level detector, switching control, detector of over-current and voltage, feedback controller and switching block, The key technology of the proposed AC-DC converting methode is detecting of the low level voltage for AC voltage, power control transistor and rectifying of DC level. The measurement results with commercial devices show that the converter has power efficiency of 66.5% for DC 12V 0.24A and the standby power is 49.58mW at AC 110V.

• Proceedings of the KOSOMBE Conference
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• v.1996 no.11
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• pp.107-110
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• 1996

We proposed a new system for the postural balance rehabilitation training. For the purpose, we used the virtual hiking system using virtual reality technology. We evaluated the system by measuring the parameters such as path deviation, path deviation velocity, cycling time, and head movement. From our results, we verified the usefulness of virtual reality technology in rehabilitation. Our results showed that this system was effective postural balance rehabilitation training device and might be useful as the clinical equipment.

• Proceedings of the KOSOMBE Conference
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• v.1996 no.05
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• pp.108-110
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• 1996

Open MRI is a new concept in clinical application of the MRI such as interventional study. Receiving RF coils used in the open MRI must have open structures to insure convenient manipulations fur the patient. In this paper, we presented experimental study fur open head coil suitable to 0.3 Tesla vertical field MRI system with its experimental results.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.170-172
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• 2007

본 논문은 optocoupler를 사용하여 궤환단을 절연한 오프라인 플라이백 변환기의 설계와 해석에 중점적인 목적을 두었으며, 부가적으로 궤환단을 절연하지 않은 구조를 가지는 전류모드제어 플라이백변환기와 optocoupler로 궤환단을 절연한 구조를 가지는 전류모드제어 플라이백 변환기의 상관관계를 분석하였다. 설계와 해석을 하기 위해 PSIM 시뮬레이터를 사용하여 PSIM 모델을 제시하였으며, 제시한 PSIM 모델은 110$\sim$220V 오프라인 전원을 입력하여 10V/5A의 출력을 가지는 50W 오프라인 전류모드 플라이백 변환기의 설계와 실험을 통하여 높은 정확성과 사용의 용이성을 확인하였다.

• Journal of Electrical Engineering and Technology
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• v.9 no.3
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• pp.882-887
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• 2014

In this paper, the water cooling method among the forced coolant cooling methods is considered to be applied to the 110kW-class IPMSM for railway vehicles. First, basic thermal property analysis of the IPMSM is conducted using the three-dimensional thermal equivalent network method. Then, based on the results of the basic thermal property analysis, some design requirements for the water cooling jacket are deduced and a basic design of the water cooling jacket is carried out. Finally, thermal equivalent circuit of the water cooling jacket is attached to the IPMSM's 3D thermal equivalent network and then, the basic thermal and effectiveness analysis are conducted for the case of applying the water cooling jacket to the IPMSM. In the future, the thermal variation trends inside the IPMSM by the application of the water cooling jacket is expected to be quickly and easily predicted even at the design step of the railway traction motor.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05a
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• pp.110-112
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• 2004

Poyethylene films can be modified by radiation grafting of N-vinyl pyrollidone using y-radiation. FTIR spectra were used to confirm the modification of PE films. The modified films were activated by two-step and one step methods for electroless Cu plating. Morphology of metallized films has been investigated. Electroless Cu plating onto the modified films depends mainly on the grafting degree and activation type. The conductivity of the metallized films has been investigated.

• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.232-233
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• 2012

This paper presents an effective control scheme for an electric vehicle battery charger where a symmetrical bridgeless power factor-corrected converter and a buck converter are cascaded. Both converters have been popular in industries because of their high efficiency, low cost, and compact size, hence combining these converters makes the overall battery charging system strongly efficient. Moreover, this charger topology can operate at universal input voltage and attain a desired battery current and voltage without ripple. In order to achieve a unity input power factor and zero input current harmonic distortion, the proposed control scheme adopts duty ratio feed-forward control technique in both current and voltage control loop. Additionally, in the current loop, its reference is created by a phase-locked loop (PLL) block, leading to a pure sinusoidal input current although the input voltage waveform is being distorted. The feasibility and practical value of the proposed approach are verified by simulation and experiment with an 110V/60Hz ac line input and 1.5kW-72V dc output of the battery charging system.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1986-1987
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• 2007

본 논문에서는 PSIM 모델을 이용하여 오프라인 전류모드 제어 플라이백 변환기의 동특성 해석과 제어기 설계방법을 제시하였다. 제시된 PSIM 모델은 시간영역 모델을 이용하기 때문에 구조가 간단하여 이용하기가 쉬우며 정확성이 높다는 장점이 있다. 그리고 $110V{\sim}220V$ 오프라인 전원을 입력하여 10V/5A의 출력을 가지는 50W 플라이백 변환기를 설계 제작하여 실험을 통해 확인하였다.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.106-110
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• 2002

4S-Van is being developed in order to provide the spatial data rapidly and accurately. 4S-Van technique is a system for spatial data construction that is heart of 4S technique. Architecture of 4S-Van system consists of hardware integration part and post-processing part. Hardware part has GPS, INS, color CCD, camera, B/W CCD camera, infrared rays camera, and laser. Software part has GPS/INS integration algorithm, coordinate conversion, lens correction, camera orientation correction, and three dimension position production. In this paper, we suggest that adequate 4S-Van design is needed according to application environment from various test results.

• Proceedings of the KIEE Conference
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• 1995.07a
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• pp.110-112
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• 1995

In this paper, We have designed the new Two-Double 1-2 phase exciting method. And We have developed the chopper constant current drive circuit in order to apply Two-Double 1-2 phase exciting method to 4-phase Stepping Motor.