• 제목/요약/키워드: resonance energy

검색결과 880건 처리시간 0.032초

파력발전기 추출파워 향상을 위한 래칭 제어기법 (Latching Control Technology for Improvement of Extracted Power from Wave Energy Converter)

  • 조일형
    • 한국해양환경ㆍ에너지학회지
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    • 제18권4호
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    • pp.282-290
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    • 2015
  • 부이의 수직운동으로부터 파랑에너지를 추출하는 파력발전기의 추출효율을 극대화하기 위하여 Sheng et al.(2015)이 제안한 래칭 제어기법을 적용하였다. 래칭 제어기법은 부이를 구속하는 래칭 시간을 조절하여 추출효율을 높이는 위상제어 방법이다. 래칭 제어기법을 규칙파중 수직운동하는 부이에 적용한 결과, 공진조건을 만족하지 않았음에도 불구하고 부이의 운동속도와 추출파워는 크게 증가하였다. 부이의 수직운동으로부터 파랑에너지를 흡수하는 파력발전기에 이러한 래칭 제어기법을 도입하면 추출파워의 증가와 더불어 부이의 흘수와 PTO감쇠력을 줄일 수 있어 제작비용을 크게 낮출 수 있다.

철의 공명에너지 영역의 에너지군구조 및 가중스펙트럼이 중성자 차폐계산에 미치는 영향 (An Effect of Energy Group Structure and Weighting Spectrum at the Resonance Energy Region of Iron on Neutron Shielding Calculation)

  • Jung-Do Kim;Yukio Ishiguro
    • Nuclear Engineering and Technology
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    • 제17권2호
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    • pp.129-135
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    • 1985
  • 중성자 차폐계산에 미치는 칠의 공명에너지 영역에서의 미세군 및 소수군 구조에 의한 효과와 축약과정에서 사용되는 가중스펙트럼에 의한 효과를 ANISN 코드와 ENDF/B-IV자료로써 평가하였다. 다루어진 문제는 소수군효과, 철의 두께 증가에 의한 영향 및 고려된 계를 대상으로한 미상군계산에서 얻은 스펙트럼을 사용한 군축약효과이다. 이용된 군정수와 코드의 정확성을 검토하기 위해, 매우 정확한 계산정도를 갖고 있는 연속에너지 Monte Carlo코드 VIM에 의한 벤치마크계산을 수행하고 결과를 비교-검토하였다.

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스택의 채널 수에 다른 열음향파의 특성 비교 연구 (A Comparative Study on the Characteristics of Thermoacoustic Waves by the Stack Channel Number)

  • 박성식;천원기;김남진
    • 한국태양에너지학회 논문집
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    • 제33권4호
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    • pp.8-14
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    • 2013
  • The conversion of solar energy into acoustic waves is experimentally studied. Measurements were made on the Sound Pressure Level(SPL), onset time and the temperature gradient across the stack, with the Cell Per Square Inch(CPSI) of stack changed. A pyrex resonance tube is used with a honey-comb structure ceramic stack along with Ni-Cr and Cu wires. An AL1 acoustical analyzer was used to measure the SPL and frequency of acoustic waves whereas K-type thermocouples were hired to estimate temperature gradients. As a result, when the supply electric power was 25W, maximum SPLs of 104.1 dB, 109.4 dB and 112.8 dB were detected for the stacks of 200, 300 and 400 CPSI and their respective stack positions of 70mm, 60mm and 50mm from the closed end.

A 64 kHz Frequency Control Using BRM for Induction Heating

  • Jamjan, K.;Thepsatorn, P.;Charean, A.;Tipsuwanporn, V.
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2003년도 ICCAS
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    • pp.1857-1861
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    • 2003
  • This paper proposes a method for controlling energy distribution to 1 phase induction heating coil by using the Binary Rate Modulation (BRM) Technique. Such method provides proper frequency to the heating coil's requirement by control the frequency at the resonance point, that is, 64-kHZ frequency band. System design are classified to 2 parts. The first part determines main frequency , and the second part generates the frequency from the 8-bit BRM derived from IC no. PAL22V10 in order to control the frequency for Full-bridge connected inverter when supplying the energy required by the 1 phase induction heating coil. Therefore, efficiency of the energy supply can be increate.

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중심의 유전체 막대가 있는 원통형공동의 전자파흡수 (EM WAVE PENETRATION INTO A CYLINDRICAL CAVITY WITH A CENTER DIELECTRIC-ROD)

  • 조철;이운동
    • 전기의세계
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    • 제28권2호
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    • pp.68-75
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    • 1979
  • The penetration of an electro-magnetic wave through an aperture in a cylindrical structure with a center dielectric-rod is investgated. By using a standard mode matching procedure, the electrical and magnetic fields in a cavity are determined as a function of position inside the cavity and frequency of the incident field. For the given parameters, computed data are obtained and the results exhibited in form of amplitude curves of the nor malized field and energy densities of functions of position and frequency. Depending on the increase of the relative dielectric constant of center dielectric-rod, the resonance frequecies of the cavity vary as the cavity size decrease. The stored electro-magnetic energy varies very rapidly as a function of position inside the cavity and of the source frequency. Its peak value can be two orders of magnitude greater than the incident energy density. The frequencies where the peaks occur can be identified approximately as the resonance frequencies of the cavity.

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방사선 처리에 의한 선충 방제 효과 (Experimental Study on Physical Control of Nematodes Using The Ionizing Radiation)

  • 이재광;유대현;이면주
    • 한국환경과학회지
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    • 제14권12호
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    • pp.1113-1117
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    • 2005
  • Gamma-ray treatment was used to exterminate nematodes, which were harmful to agriculture When gamma-ray at the dose range of $5\~75$ kGy was irradaidated, nematodes were reduced by $40\~50\%$ When irradiated over 30 kGy, almost nematodes were non-mobile and fluorochromatic reactions showed that $60\;\~80\%$ of nematodes with non-mobility died after irradiation. The results of electron spin resonance spectroscopy suggested that radicals generated by radiolysis could damage to nematodes.

파도에너지를 효율적으로 이용하기위한 파력진동발전기에 대한 연구 (The research of vibration power generation to make effective use of ocean wave energy)

  • 이홍찬;이재호;한기봉
    • 한국마린엔지니어링학회:학술대회논문집
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    • 한국마린엔지니어링학회 2011년도 후기공동학술대회 논문집
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    • pp.75-75
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    • 2011
  • This paper has been studied that ocean wave vibration power generator is composed of buoy and vibration generator to make effective use of ocean wave energy. We designed buoy to can occur resonance for dominant frequency with ocean wave. And then we fitted the natural frequency of vibration system with vibration power generator to buoy's natural frequency. And we can show that the amplitude of ocean wave up and down motion is decreased, on the other hand, the displacement of vibration system with vibration power generator is increased. Therefore, ocean wave vibration power generator which is proposed in this paper has merits not only securing its stability from surroundings but also producing more electronic power by using ocean wave energy.

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Single-molecule Detection of Fluorescence Resonance Energy Transfer Using Confocal Microscopy

  • Kim, Sung-Hyun;Choi, Don-Seong;Kim, Do-Seok
    • Journal of the Optical Society of Korea
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    • 제12권2호
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    • pp.107-111
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    • 2008
  • We demonstrated single-molecule fluorescence resonance energy transfer (FRET) from single donor-acceptor dye pair attached to a DNA with a setup based on a confocal microscope. Singlestrand DNAs were immobilized on a glass surface with suitable inter-dye distance. Energy transfer efficiency between the donor and the acceptor dyes attached to the DNA was measured with different lengths of DNA. Photobleaching of single dye molecule was observed and used as a sign of single-molecule detection. We could achieve high enough signal-to-noise ratio to detect the fluorescence from a single-molecule, which allows real-time observation of the distance change between single dye pairs in nanometer scale.

저주파수 진동형 전자기식 마이크로 발전기의 설계 및 해석 (Design and Analyses of Vibration Driven Electromagnetic Energy Harvester with High Power Generation at Low Frequency)

  • 이병철;정귀상
    • 센서학회지
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    • 제20권2호
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    • pp.102-106
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    • 2011
  • This paper presents a design and analysis of an electromagnetic micro generator which can convert low frequency vibration energy to electrical power. The design aspects of the micro generator comprised planar spring, Cu coil and a permanent magnet(NdFeB). Threetype spring designs and four materials(Parylene, FR-4, Cu and Si) were compared to find resonance frequency. It was found that the resonance frequency will be changed according to the spring shape and material. Mechanical and magnetic parameters had been adjusted to optimize the output power through a comprehensive theoretical study.