• 전기학회논문지P
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• 제58권4호
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• pp.588-591
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• 2009

We had experimental studies of microwave output generator. We experimented with a corrugate-shped K-band slow wave guide in the backward wave oscillator. It generated output 표 interaction between electron beam's generation and magnetic field. We estimated oscillation frequency at 24GHz by changing propagation velocity and group velocity. We identified movement by second harmonic of Cherencov interaction and slow cyclotron mode. In our study we achieved oscillation stabilization, generation of long pulse, improvement of oscillation efficiency and output.

• 한국정보통신학회논문지
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• 제7권5호
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• pp.1013-1018
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• 2003

본 논문은 이차여자 유도발전기시스템의 파력발전시스템에의 적용에 관한 연구내용을 요약한다. 불규칙적인 파력 입력에 따라 변화하는 발전기의 출력을 슬립주파수에 맞추어 컴퓨터로 이차전류를 제어하여 출력전압과 출력전류를 안정화시키고자 하였다. 본 논문에서 제안한 방법을 확인하기 위하여 실험실 레벨의 파력 시뮬레이터를 제작한 후 이차여자 유도발전기를 구동하였다. 파력과 같은 불규칙입력 발전시스템에 대한 이차여자 유도발전 시스템의 유효성을 실험적으로 확인하였다.

• 한국해양환경ㆍ에너지학회지
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• 제19권3호
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• pp.185-193
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• 2016

본 연구에서는 부유식 풍력-파력 복합발전 플랫폼 안에 설치된 다수 파력발전기의 현 배치안을 부체 간의 상호 간섭효과를 고려하여 평가하였다. 다수 부체가 수면 위에 떠 있는 경우, 순수한 입사파와 함께 인접한 부체에 의해 발생하는 산란파와 방사파의 영향으로 인해 다수 부체 간의 상호작용 과정은 매우 복잡하다. 다수 파력발전기 배열에 따른 회절 및 방사 문제의 상호작용 해석을 위하여 고유함수전개법을 적용하였다. 해석해의 타당성을 검증하기 위하여 상용 프로그램인 WAMIT으로부터 계산된 수치계산 결과와 비교하였다. 다수 부체 간의 상호 간섭효과를 나타내는 q-factor를 이용하여 복합발전 플랫폼내의 24기 파력발전기의 현 배치안에 대한 전체 성능을 평가하였다.

• 한국해양환경ㆍ에너지학회지
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• 제14권1호
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• pp.11-18
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• 2011

암초형 월류 파력발전 시스템은 암초형 구조물에 입사 되는 파랑 에너지를 낙차로 전환하고 이를 전기 에너지로 변환 시키는 파력 발전 방식이다. 기존 연구에서 월파제의 사면 경사, 천단고, 가이드 베인 형상에 따른 월류 성능이 연구 되었다. 본 연구에서는 이러한 기존 연구를 통해 설계된 1/7 축소 모형을 제작하고 수차 터빈 및 발전 시스템, 전력제어시스템, 운전제어 및 모니터링 시스템을 연계하여 통합 축소 모형 시스템을 구축하였다. 이러한 시스템에서 서로 다른 파고와 주기를 갖는 파에 따른 월류량과 발전량을 계측하여 기존 연구와 비교 검증하였다. 이를 통해 설계시 계획한 월류량과 발전량을 확인하였고 다수 터빈에 의한 효율적인 제어 시스템 구동 방안을 제안하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 1998년도 제14회 학술발표회 논문개요집
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• pp.178-178
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• 1998

Bacuum ppower tubes (gyrotron klystron gyro-klystron etc) are attractive for high ppower applications such as radar/communications pplasma heating accelrator naterial pprocessing etc. Over the ppast two decades considerable efforts on the developpment of gyrotron-ppower coherent microwave and millimeter wave sources were made. Expperimental pperformance on the gyro-devices will be ppresented.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.167.1-167.1
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• 2011

Sustainable energy generation is becoming extremely imperative due to the expected limitations in current energy resources and to reduce pollution. Especially, because of its considerable energy potential, ocean wave energy has been investigated with regard to power generation. To develop large high power wave generator system, it is important to make a small scale proto type and to test that. Thus the objective of this research is to examine the characteristics of a mechanically excited generator system having small power capacity experimentally. The water reservoir (4 m length, 1.5 m width and 1.8 m depth) having a wave maker to make arbitrary height and period of the water wave was made. The proto type consists of three main parts; a buoy, rack-pinion base one-way mechanism, and a wave generator(Fig.1). The water wave is going up and down and the hexahedron buoy is following the wave. The rack gear attached to the buoy is also going up and down to roll the pinion connected to an electric generator then it produces electricity. The experiments were performed with several conditions of water waves, and the power outputs over 30 W could be measured for some conditions. In future works, to achieve higher performance for the proto type, the effects of primary parameters (buoy shape and mass, etc.) on the system efficiency will be identified.

• 한국산업융합학회 논문집
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• 제23권5호
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• pp.835-842
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• 2020

This paper considers a method of reproducing abnormal and fault operation for smart monitoring of thrust bearing used in wave power generation system. In order to develop smart monitoring technology, abnormal and failure data of actual equipment are required. However, it is impossible to artificially break down the actual equipment in operation due to safety and cost. To tackle this problem, a test bed that can secure data through reproduction of a faulty operating environment should be developed. Therefore, in this study, test bed that can reproduce each situation was developed and the operation result was analysis after identifying the situation to be reproduced through the failure factor analysis of the thrust bearing.

• KIEE International Transactions on Power Engineering
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• 제12A권1호
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• pp.26-30
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• 2002

The four fuzzy criteria to distinguish the internal fault from the inrush fur the power transformer protection have been identified. They are based on the wave shape, terminal voltage, fundamental and second harmonic component of differential current. systematic way to determine the associated fuzzy membership function is also proposed.

• International Journal of Naval Architecture and Ocean Engineering
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• 제9권3호
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• pp.239-245
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• 2017

As a new technical approach, wave energy converter by using vertical motion of water in the multiple water chambers were developed to realize actual wave power generation as eco-environmental renewable energy. And practical use of wave energy converter was actually to require the following conditions: (1) setting up of the relevant device and its application to wave power generation in case that severe wave loading is avoided; (2) workability in installation and maintenance operations; (3) high energy conversion potential; and (4) low cost. In this system, neither the wall(s) of the chambers nor the energy conversion device(s) are exposed to the impulsive load due to water wave. Also since this system is profitable when set along the jetty or along a long floating body, installation and maintenance are done without difficulty and the cost is reduced. In this paper, we describe the system which consists of a float, a shaft connected with another shaft, a rack and pinion arrangement, a ratchet mechanism, and rotary type generator(s). Then, we present the dynamics model for evaluating the output electric power, and the results of numerical calculation including the effect of the phase shift of up/down motion of the water in the array of water chambers aligned along the direction of wave propagation.

• 동력기계공학회지
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• 제17권5호
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• pp.38-43
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• 2013

In order to design a wave energy generating system, a 6-DOF analysis technique is applied to CFD analysis on of a floating body and the behavior is interpreted according to the nature of the incoming waves. A spring constant is adopted to control the motion of multi floating bodies and to calculate the total average power absorption. Three cases of different wavelengths namely 20D, 30D and 40D have been modeled to analyze the total average power absorption. The average power absorption not only varies with the position of the floating body but also varies with wavelength. From the results obtained, it is concluded that the maximum total average power absorption is 9W approximately in wavelength 30D and the minimum total average power absorption is 4.3W approximately in wavelength 40D.