• Title/Summary/Keyword: Resonance

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Efficiency evaluation and characteristics of receiver coil under different inserted resonance coils in wireless power charging system for MAGLEV

  • Chung, Yoon Do;Jeon, Haeryong
    • Progress in Superconductivity and Cryogenics
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    • v.20 no.1
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    • pp.23-27
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    • 2018
  • As the wireless power transfer (WPT) technology based on strongly resonance coupled method realizes large power charging without any wires through the air, there are advantages compared with the wired counterparts, such as convenient, safety and fearless transmission of power. From this reason, the WPT systems have started to be applied to the wireless charging for various power applications such as train, underwater ship, electric vehicle. This study aims for the effect and characteristics of different inserted resonance coil between Tx and Rx coils for charging system of superconducting magnetic levitation (MAGLEV) train. The transfer efficiency and effect are evaluated with helix type, rectangular type copper resonance coil, and HTS resonance coil under bulb and HTS magnet load, respectively. The input power is adapted with radio frequency (RF) power of 370 kHz below 500 W.

A Study on the Presure Resonance with Combustion Chamber Geometry for a Spark Ignition Engine (스파크 점화기관의 연소실 형상에 따른 공진현상 해석에 관한 연구)

  • Park, Kyoung-Suk;Jang, Seok-Hyung
    • Proceedings of the KSME Conference
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    • 2001.06d
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    • pp.890-895
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    • 2001
  • Pressure resonance frequency that is caused in the combustion chamber can be interpreted to acoustic analysis. Until now the pressure resonance has been assumed and calculated to a disc type combustion chamber that neglected the combustion chamber height because the knock occurs near the TDC(top dead center). In this research FEM(fine element method) has been used to calculate the pressure resonance frequency inside the experimental engine combustion. The reduce error of the resonance frequency obtained by FEM has decreased about 50% compared to the calculation of Draper's equation. Due to the asymmetry in the shape of the combustion chamber that was neglected in Draper's equation we could find out that a new resonance frequency could be generated. To make the experimental results equal we could know that the speed of sound that satisfies Draper's equation was selected 13% higher than all the pent-roof type combustion considered.

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Structural Studies on IRES 4-2 Domain of Foot-and-mouth Disease Virus

  • Kim, Young-Mee;Yoo, Jun-Seok;Cheong, Hae-Kap;Lee, Chul-Hyun;Cheong, Chae-Joon
    • Journal of the Korean Magnetic Resonance Society
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    • v.7 no.2
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    • pp.89-97
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    • 2003
  • Foot-and-mouth disease virus (FMDV) belongs to the aphthovirus genus within the picornavirus which has a single copy of a positive sense RNA. The translation initiation process of FMDV occurs by a cap-independent mechanism directed by a highly structured element (∼435 nt) termed an internal ribosome entry site (IRES). We have designed and prepared FMDV 4-2 RNA (28nt) by in vitro transcription. The 2D NMR data revealed that FMDV 4-2 IRES domain RNA has a flexible loop and bulge conformation. In further study, we need to make an isotope labeled RNA sample and conduct 3D NMR experiments to completely determine the 3D structure. This study may establish a new drug design strategy to treat foot-and mouth disease.

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Energy Calibration for Neutron Capture Resonance of Natural Sm by Using 46-MeV Electron Linear Accelerator

  • Lee, Jae-Hong;Lee, Sam-Yol
    • Journal of the Korean Society of Radiology
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    • v.1 no.2
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    • pp.31-35
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    • 2007
  • Energy calibration is important to identify accurate neutron capture resonance energy in the neutron TOF (Time-of-Flight) experiment. In present study, the accurate neutron capture resonance energies of natural Sm were measured by using a 46-MeV electron linear accelerator (linac) at the Research Reactor Institute, Kyoto University(KURRI). The BGO spectrometer were adopted for measurement the prompt capture gamma-ray of the sample. To obtain energy calibration curve, resonance energy of a gold sample used as standard resonance energy Mughabghab's data (From neutron resonance parameters data). Previous data (by Mughabghab) of natural Sm sample have been compared with the present result.

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Resonance avoidance and Safety Evaluation of Vertical Pump (입형펌프의 공진회피와 안전성 평가)

  • Jeong, Wooyoung;Song, Jindae
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2013.04a
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    • pp.698-702
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    • 2013
  • This paper considers the vertical pumps resonance and soundness. Normally large vertical pump's rotating speed is low, so the low natural mode can make a resonance on the motor and motor stand assembly. The pump resonance makes a very high vibration and trouble on the pump systems. Thus to avoid pump resonance when the pump is on the resonance region, we give the added mass method and evaluate the structure soundness by computer simulation and test on the site. Furthermore we evaluate the modal sensitivity and expect running conditions by the using ISO10814.

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Nondestructive Inspection Method of Composite Laminated Plates by Holographic Interferometry (홀로그래피 간섭계를 이용한 복합적층판의 결함측정)

  • 김석중;김재형;박현철
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.12
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    • pp.3202-3218
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    • 1994
  • Mode shapes and natural frequencies of vibrating laminated composite plates are taken using real-time and time-average holographic interferometry. Debonds and delamination in the laminated plates are measured nondestructively. During holographic testing of composite plates, it has been found that the conditions for the local resonance in debonds are strongly dependent on the frequency of excitation. A membrane resonance model was proposed to describe this behavior. Relations between characteristic length according to the size, shape of debonds and membrane resonance frequency are presented. Several experiments were performed to verify the membrane resonance model. The agreements between the predicted excitation frequency and the observed resonance frequency are good. The experimental results show that higher stresses and strains due to local resonance lead to the debond detection.

Ferromagnetic resonance of Hensler $Ni_2$MnGa thin films

  • M. D. Huang;Lee, N. N.;Lee, Y. P.;J. Y. Rhee;J. Dubowik
    • Journal of the Korean Vacuum Society
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    • v.12 no.S1
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    • pp.116-119
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    • 2003
  • $Ni_2$MnGa films, deposited on mica and glass substrates, were studied by ferromagnetic resonance (FMR) technology. The temperature-dependent resonance field was measured and a martensitic phase transformation (MT) was found between 310 and 340 K, exhibiting an abnormality on the curve. The easy axis is found to be in the film plane. The line width increases as a whole with decreasing temperature, which is discussed in terms of the motional narrowing mechanism. The resonance field was also measured as a function of orientation and the results were fitted, exhibiting a good consistence.

A Wide-band Multi-layer Antenna Design using Double Resonance (이중공진을 사용한 적층기판용 광대역 안테나 설계)

  • Lee, Kook-Joo;Zhang, Mei-Shan;Lee, Jung-Aun;Han, Myeong-Woo;Kim, Moon-Il
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.2
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    • pp.431-434
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    • 2011
  • In this paper, bandwidth enhanced design of dielectric resonator antenna fabricated in multi-layer substrate is introduced. The proposed dielectric resonator antenna is operating with fundamental TE101 mode and higher-order TM111 mode. Each resonance frequency is dependent on resonator dimensions. As increasing the height of radiating aperture, the higher-order TM111 mode resonance frequency approach the fundamental TE101 mode resonance frequency and the antenna bandwidth increase by double resonance. Three different aperture height size antennas that operated at 7GHz are fabricated in FR4 multi-layer substrate. Measured 10 dB matching bandwidth is 8 percent for single resonace antenna and 18 percent for double resonance antenna.

Analysis of the Efficiency According to Resonant Repeater Application in Magnetic Resonant Wireless Power Transfer System (자기공진방식의 무선전력전송 시스템에서 공진 중계기 적용 여부에 따른 전력전송 효율 분석)

  • Baek, Seung-Myung;Kim, Dong-Eun;Shon, Jin-Geun
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.67 no.4
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    • pp.221-226
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    • 2018
  • In this paper, the power transfer efficiency analysis based on the resonant repeater in a magnetic resonance wireless power transfer system is proposed. The efficiency of the magnetic resonance method was verified by comparing the general frequency with the resonance frequency. The resonance repeater was arranged to increase the efficiency and increase the transfer distance. When using resonant repeaters, the maximum efficiency increase is about 36.23[%] and the transfer distance was extended to more than 20[cm]. Through this study, confirmed the effect of using resonance repeaters in wireless power transfer system. As a result, it can be expected that the overall technology related to wireless power transfer system will be more valuable for energy-IT technology.