• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(1)
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• pp.219-222
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• 2002

In this paper, we propose the OADM based on a Mach-Zehnder interferometer(MZI) with FBG(fiber Bra-gg grating) in the interferometer arms. The OADM us ing FBG and MZI is able to minimize system and red uce weight. We analyze output\ulcorner characteristics of OAD-M, and present the optimum design data through the computer simulation, and obtain the good experimental results. Also, the proposed OADM is suitable to DWD-M(Dense WDM) system because it has the narrow 1-inewidth.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(1)
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• pp.223-226
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• 2002

In this paper, we propose the FBG design using coupled mode theory based on perturbation theory. FBG can be used to extract the specific wavelength channel from the transmission ]me when many wavelengths are coupled in a multiwavelength transmission line. To analyze output characteristics of FBG and get optimum design data, we simulate through computer and verify by experiment. From the results obtained by simulation and experimentation, the proposed FBG fits for DWDM(Dense WBM) system because of the tunning narrow linewidth.

• 한국해안·해양공학회논문집
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• 제32권1호
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• pp.48-54
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• 2020

로터 위치 및 쉬라우드 입구 유속 변화에 따른 쉬라우드 내부 유동장 및 기계적 출력 분석을 위해 수치해석을 수행하였고 이를 실험결과와 비교하였다. 로터와 해수의 유동조건은 쉬라우드 조류발전 시스템 내 유동장 특성에 많은 영향을 미치게 된다. 특히 실린더 내 축 방향 위치에 따른 로터의 기계적 출력은 실린더 중앙 이후까지 점차 증가하며, 입·출구 부근에서는 감소하였다. 또한 쉬라우드 입구 유속이 증가함에 따라 로터 출력량이 점차 증가하였다. 축 방향 운동량과 각운동량은 로터를 통과하면서 급격하게 증가 및 감소하였으며, 전방을 포함한 그 외 영역에서의 큰 변화는 없었다. 이러한 결과들은 조류발전 시스템 개발의 기초 자료로 다양하게 활용될 수 있을 것으로 기대된다.

• 전력전자학회논문지
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• 제4권5호
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• pp.397-404
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• 1999

본 연구에서는 선형화 소신호 모델을 이용하여 불연속 모드 펄스폭 공진회로의 다양한 제어방법에 대하여 조사 하였다. 각 제어방식에 따른 시스템의 안정도와 동적 특성을 분석하기 위하여 정규화 출력 전류와 전압을 사용한 근궤적을 나타내었다. 또한, 최적의 궤적 특성을 가지는 제어기를 새로이 제안하였으며, 이러한 제어의 우수한 특성을 다른 형태의 제어방식과 비교함으로써 입증하였다.

• 대한전기학회논문지
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• 제41권2호
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• pp.125-134
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• 1992

This paper presents a cycloconverter with an LC resonant circuit for an induction motor drive. The cycloconverter can keep input displacement factor at 1.0 by independently controlling real and reactive power under any load conditions. Furthermore it can keep power factor at about 1.0 since input and output current waveforms are nearly sinusoidal. Since it uses high frequency resonant circuit for commutation source, it can produce an output voltage of hundreds of hertz. Since it is also possible to make a system of high capacity using the cycloconverter, it is appropriate to drive motors with high speed and high capacity as well as general purpose motors, In this paper, we describe the operating principles of the cycloconverter and power control algorithms, and analyze its waveforms and present its characteristics. Expermental results are shown for the volts/hertz control of the induction motor and the validity of the proposed model is verified.

• 전기학회논문지
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• 제56권12호
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• pp.2240-2246
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• 2007

Optically coupled linear isolation amplifier requires special care to avoid oscillation in actual applications. In this paper methods to analyze the frequency characteristics of the amplifier are proposed to reveal the cause of oscillation and to provide design guidelines. The loop gain of the amplifier obtained through the equivalent circuit model shows that the phase margin is too small to ensure stable operations. Methods to get non-oscillatory response are proposed and the resulting frequency responses are analyzed. The common method adding a small capacitor to the amplifier is shown to degrade the frequency bandwidth. The frequency response of output voltage explains the need of filter capacitor in output stage. The usefulness of the method is verified through experiments.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2002년도 전력전자학술대회 논문집
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• pp.485-488
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• 2002

DC-DC converter for KOMPSAT 2 has been designed to satisfy input current, and output voltage ripples constraints, in this paper. The converter has been simulated to analyze small signal characteristics. The resulted phase margin of the converter is above $60^{\circ}$. The DC-DC converter has been experimented for 93kHz, 90W output load.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(2)
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• pp.828-831
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• 2003

This paper presents a novel design technique and characteristic analysis of Magnet for dual air-gap axial-flux type permanent-magnet synchronous generator. The process of magnet design is applied to the motor design and steady state analysis considering output voltage waveforms and magnetic flux waveforms. Design and construction of an axial-flux permanent-magnet generator with power output at 60 [Hz], 300[r/min] is introduced. Finite-element (FE) method is applied to analyze magnet shape characteristics. The results of FE analysis show generator is feasible for use with dual air-gap axial-flux permanent- magnet synchronous generator.

• Journal of international Conference on Electrical Machines and Systems
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• 제2권3호
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• pp.260-268
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• 2013

Based on classical Berotti discrete iron loss calculation model, the iron loss analysis mathematical model of alternator was proposed in this paper. Considering characteristics of high speed and changing frequency of the alternator, Maxwell 3-D model was built to analyze iron loss corresponding to each running speed in alternator. Based on iron loss model of alternator at rated speed, the rotor claw pole size was made an optimization design. The optimization results showed that alternator's output performance had been improved. A new idea was explored in size optimization design of claw pole alternator.

• 한국통신학회논문지
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• 제18권4호
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• pp.481-489
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• 1993

등간격의 전극구조를 갖는 탄성표면파 필터의 정전계적 임피던스 해석을 위하여 무한개의 인접전극의 정전계적 상호작용을 해석하여 전극의 구조에 따른 전하분포를 구현하였는데, 이는 Element Factor와 Array Factor로 분리하여 계산할 수 있었다. 임의의 전극 구조를 갖는 탄성표면과 필터의 입력 및 출력 전극의 Radiation Conductionce, Susceptance 및 static Capacitance는 이러한 전극에서의 전하분포를 통하여 구하였고 Apodized IDT의 임피던스는 Multi-Track 해석에 의하여 다수의 Uniform Track의 병렬 연결로써 계산하였다. 이와 같이 얻어진 입.출력 전극의 임피던스를 실제로 제작된 필터의 측정 임피던스와 비교한 결과 잘 일치하였다.