• 한국인터넷방송통신학회논문지
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• 제23권4호
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• pp.143-148
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• 2023

SRM의 특성 중 비선형성으로 인해 최대토크 및 최소 토크 맥동 형성을 위한 적정 운전이 어렵다. 또한 고정 스위칭각 제어 때 속도 가변에 따른 토크 형성이 불안정하여 효율을 저하시키는 문제점을 가지고 있다. 따라서 속도 가변에 따른 능동적인 스위칭각 제어가 필요하다. 본 논문에서는 SRM의 비선형성으로 인한 문제점으로부터 선행각 (Advance angle)의 자동제어에 의한 토크 리플 저감과 이에 따른 출력 토크 향상에 의한 구동 성능개선을 위한 방법에 대해 모색하였다. 또한 히스테리시스 전류제어기 성능에 따른 스위칭 가변으로 인한 SRM의 최적 운전에 대해 살펴보았다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
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• pp.236-241
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• 2001

This paper presents a novel prototype of active voltage-clamping capacitor-assisted edge resonant soft switching PWM inverter operating at a constant frequency variable power (VPCF) regulation scheme, which is suitable for consumer high-power induction-heating cooking appliances. New generation IGBT with a trench gate is particularly improved in order to reduce conduction loss due to its lowered saturation voltage characteristics. The soft switching load resonant and quasi-resonant inverter designed distinctively using the latest IGBTs is evaluated from an experimental point of view.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 추계학술대회논문집
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• pp.743-748
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• 2008

This paper presents an inertia type of piezostack based active mount for unmanned aero vehicle (UAV) camera system. After identifying the stiffness and damping properties of the rubber element and piezostack a mechanical model of the active mount system is established. The governing equation of mount is them derived and expressed in a state space farm. Subsequently, a sliding mode controller which is robust to uncertain parameters is designed in order to reduce the vibration imposed according to the military specification associated with UAV camera mount system operation. Control performances such as acceleration and transmitted force are evaluated through both computer simulation and experimental implementation.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.269-275
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• 2005

This article describes the development on a new style active hybrid bearing system including both merits of an aerostatic bearing system and a magnetic bearing system. The developed active hybrid bearing system has several advantages: exact rotation, robust controller against the variation of a disturbance, improvement of stiffness and a damper of the system at a high-speed operation, and constraints of the heat generated by a bias current. In order to measure a rotating error due to the change of a cutting force and the variation of a system parameter, a CCS (Cylindrical Capacity displacement Sensor) was used.

• 전기학회논문지P
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• 제58권2호
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• pp.116-121
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• 2009

Distributed power systems (DPSs) has been widely used various industrial/military applications due to their various advantages. Furthermore, the "All electric" concept, in conjunction with DC DPS, appears to be more advanced and mature in the AEV(All-Electric Vehicular) industry. Generally, AEV carry many loads with varied functions. However, there may be large pulsed loads with short duty ratios which can affect the normal operation of other loads. In this paper, a converter with spilt capacitors and a simple adaptive controller is proposed as a active damping device to mitigate the voltage transients on the bus. The proposed converter allows the smaller capacitive storage. In addition, the proposed control approach has the advantage of requiring only one sensor and performing both the functions of mitigating the voltage bus transients and maintaining the level of energy stored. The control algorithm has been implemented on a TMS320F2812 Digital Signal Processor (DSP). Simulation and experimental results are presented which verify the proposed control principle and demonstrate the practicality of the circuit topology.

• Journal of Power Electronics
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• 제1권1호
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• pp.9-18
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• 2001

The performance analysis of a three-phase parallel active power filter that compensates PCC voltage and the unbalanced loads is presented in this paper. The proposed scheme in this paper employs a PWM voltage-source inverter and has two operation modes. Firstly, it operates as a conventional active filter with reactive power compensation when PCC voltage is within the 15% voltage drop range. Secondly, it operates as a voltage compensator when PCC voltage is not within the 15% voltage drop range. And both APF and voltage compensator compensate asymmetries caused by nonlinear loads. Finally, two methods of detecting the negative sequence are reviewed, and the validity of this scheme is investigated through analysis of simulation and experimental results for a prototype active power filter system rate at 10KVA.

• 한국경영과학회지
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• 제21권3호
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• pp.75-88
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• 1996

This paper presents an efficient heuristic technique for minimizing the objectives related to tardiness such as total tardiness, maximum tardiness and root mean of tardiness in the job shop scheduling. The heuristic technique iteratively improves an active schedule through exploring the schedule's neighborrhood, using operation move methods. The move operatio is defined on an active chain of tardy jobs in the active schedule. To find the move operations which have a high probability of reducing tardiness, we develop move methods by exploiting the properties of active chains. Our technique is compared with the two existing heuristic techniques, that is, MEHA(Modified Exchange Heuristic Algorithm) and GSP(Global Scheduling Procedure) under the various environmental with the three levels of due date tightness and several sized problems. The experimental results show that the proposed technique outperforms the two exissting techiques in terms of solution quality and computation time.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(2)
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• pp.257-260
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• 2002

This paper describes the pixel of AMOLED(act ive matrix organic light emitting diode) driving circuit by poly-sl technology. The area per pixel is 278um$\times$278um in 120$\times$160(2.2 inch) Driving the OLEDS with active matrix leads to the lower voltage operation, the lower peak pixel currents and the display with much greater efficiency and brightness The role of the active matrix is to provide a constant current throughout the entire frame time and is eliminating the high currents encountered In the passive matrix approach, This design can support the high resolutions expected by the consumer because the current variation specification is norestricted. The pixel has been designed driving TFT threshold voltage cancellation circuit and wide aperture ratio circuit that communizes 4 pixel. The test simulation results and layout are 11% per threshold-current var Eat ion and 12.5% the aperture ratio of increase.

• 전자공학회논문지T
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• 제36T권4호
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• pp.53-59
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• 1999

본 논문에서는 전력용 능동필터의 성능을 가지는 양방향성 무정전 전원장치를 제안한다. 제안된 시스템은 전력용 능동필터모드와 배터리 방전전력모드인 2가지 모드로 나누어진다. 전력용 능동필터모드에서 고조파전류와 무효전력을 효과적으로 보상하기 위하여 기준전류를 계산하는데, 새로운 폐-루프 제어기법이 사용된다. 마지막으로, 제안된 무정전 전원장치의 성능이 시뮬레이션과 실험에 의해 검증된다.

• 한국군사과학기술학회지
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• 제9권1호
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• pp.33-40
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• 2006

A compact broadband active composite dipole antenna for direction finding system at the V/UHF-band is presented. It uses the composite structure which improves the antenna gain and the active circuit for broadband operation. This type of antenna has a high gain more than that of one dipole antenna within limited length(1m). The basic design and performance of both antenna structure and integrated active circuit are presented.