• Title/Summary/Keyword: Mode Interference

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A Study on Electromagnetic Interference of Electric Vehicles with Variations of Charging Device Inlet Location (전기자동차 충전구 위치에 따른 전자파 방사특성에 관한 연구)

  • Gwon, Sunmin;Woo, Hyungu
    • Transactions of the Korean Society of Automotive Engineers
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    • v.24 no.6
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    • pp.694-701
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    • 2016
  • According to revolutionary developments in automobile technologies, eco-friendly advanced vehicles (hybrid vehicle, hydrogen fuel-cell vehicle, electric vehicle, etc.) are rapidly increasing. The electromagnetic compatibility is getting more important for development of a vehicle because those advanced vehicles are driven by electric energy and equipped with more electric systems. In general, electromagnetic compatibility tests consist of an electromagnetic interference(EMI) test and an electromagnetic susceptibility(EMS) test. EMI test of the electric vehicles are needed not only in driving mode but also in charging mode because they must be recharged by much electric energy for driving. Depending on vehicle manufacturers, the charging device type and the location of charging device inlet in electric vehicles are various. In this paper, in order to investigate EMI of electric vehicles in charging mode in consideration of the direction of measuring antenna and the location of charging device inlet, a series of electromagnetic emission tests are conducted using three electric vehicles (neighborhood electric vehicle, electric vehicle and electric vehicle-bus). The test results show that electromagnetic emission measurements in charging mode are dependent on the direction of measuring antenna and the location of charging device inlet.

Comparison of Primary Stability of Different Femoral Fixation Techniques in Anterior Cruciate Ligament Reconstruction (전 십자 인대 재건술에서 대퇴골측 고정 방법의 초기 안정성의 비교)

  • Song, Eun-Kyoo;Lee, Keun-Bae;Lee, Moon
    • Journal of the Korean Arthroscopy Society
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    • v.2 no.1
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    • pp.85-92
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    • 1998
  • Various methods for fixation of graft have been widely used for reconstruction of anterior cruciate ligament. However, the biomechanical strength of each fixation techniques are not fully understood. The purpose of this study is to compare the pull out strength of different fixation techniques which is probably the most important factor for the success at the initial stage of healing. Biomechanical test was carried out to measure and compare the pull out tensile strength of five different fixation techniques in 35 pig(Yorkshire) knees. ANOVA and Duncan multiple comparison test was applied for statistical analysis. In the two fixation techniques with bone patellar tendon bone graft, the mean maximum tensile strength was $1333.4{\pm}148.5N$ with titanium interference screw, while it was $1310.1{\pm}168.9N$ with biodegradable interference screw. The failure mode were pulled out of bone plugs from the femoral tunnel in majority cases. In the fixations with hamstring tendon, the mean maximum tensile strength were $1405.9{\pm}135.1N$ with SemiFix screw, $820.3{\pm}104.5N$ with biodegradable interference screw, and $682.1{\pm}54.2N$ with Endobutton. The mode of failure was variable in each technique. The tendon was pulled out from the tunnel in biodegradable interference screw fixation, the screw was bent in the SemiFix system, and the polyester tape were ruptured or the buttons were pulled into tunnel in Endobutton fixation. The mean maximum tensile strength of two interference screws with bone patellar tendon bone was statistically comparable to that of SemiFix with hamstring tendon. However biodegradable interference screw and Endobutton with hamstring tendon showed weaker maximum tensile strength than above three fixation techniques (P<0.05).

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Analysis and Design of Si3N4 Rib-optical Waveguides for Evanescent-wave Integrated-optical Biosensors (소산파 집적광학 바이오센서에 적합한 Si3N4 립-광도파로 해석 및 설계에 관한 연구)

  • Jung, Hongsik
    • Korean Journal of Optics and Photonics
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    • v.30 no.1
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    • pp.15-22
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    • 2019
  • $Si_3N_4$ rib-optical waveguides for evanescent-wave integrated-optical biosensors were analytically interpreted, to derive the single-mode propagation conditions. The integrated-optical biosensor structure based on two-mode interference was proposed, and the rib width and thickness and core thickness for a single-mode and two-mode waveguide (sensing region) were proposed to be $3{\mu}m$, 2 nm, and 150 nm and $3{\mu}m$, 20 nm, and 340 nm respectively. The optical characteristics of each guided-wave mode were investigated utilizing the film mode-matching (FMM) analysis.

Interference of Acoustic Signals Due to Internal Waves in Shallow Water

  • Na Young-Nam
    • Proceedings of the Acoustical Society of Korea Conference
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    • spring
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    • pp.189-197
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    • 1999
  • To investigate internal waves (IW) effect on acoustic wave propagation, m analysis is conducted on mode travel time and model simulation. Based on the thermistor string data, it can be shown that the thermocline depth variation may cause travel time difference as much as 4-10 ms between mode 1 and 2 over range 10 km. This travel time difference causes interference among modes and thus fluctuation from range-independent stratified ocean structure. In real situations, however, there exist additionally spatial variation of IW. Model simulation with all modes and simple IW shows clear responses of acoustic signals to IW, amplitude and phase fluctuation.

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Design of 4$\times$4 Thermo-optic Switch using Two Mode Interference coupler (두모드간섭 현상을 이용한 4$\times$4 열광학스위치 설계)

  • 정명선;김정근
    • Proceedings of the IEEK Conference
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    • 2003.11c
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    • pp.357-360
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    • 2003
  • In this paper, we investigated the characteristics of 4${\times}$4 thermo-optic switch using two mode interference(TMI) coupler. We designed this matrix switch by using a configuration which combines a double Mach- Zehnder interferometer(MZI) switching unit. The average extinction ratio and average excess loss of the 4${\times}$4 thermo-optic switch was 33.7dB, 0.29dB, respectively.

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Effective Interference Cancellation method on W-CDMA TDD Syetem (W-CDMA TDD 방식에서의 효율적 간섭 제거 기법)

  • 조영보;고균병;권동승;정인철;강창언;홍대식
    • Proceedings of the IEEK Conference
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    • 2001.06a
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    • pp.101-104
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    • 2001
  • In TD-CDMA system, multi-user interference degrades the system performance. In this paper, we propose a effective multi-user detection algorithm applicable to TDD mode. We certify a channel estimation capacity by using midamble and performance of the proposed multistage interference canceller in the system complex aspect. In computer simulations, it is verified that proposed algorithm has lower complexity and better performance than conventional multi-user interference cancellation in Rayleigh fading channel.

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Electromagnetic interference caused by an electric-line current in a cable tray in nuclear power plants

  • Lee, Hoon-Keun;Kim, Yong-Hwa;Choo, Jaeyul
    • Nuclear Engineering and Technology
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    • v.53 no.10
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    • pp.3314-3318
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    • 2021
  • This paper presents a mode-matching analysis of the electromagnetic coupling between open cable trays in an indoor structure when an electric-line current is generated as an electromagnetic source. We validated the mode-matching method by comparing the mode-matching results with those computed from a commercial electromagnetic simulator and then investigated the strength of the electric-field coupled in a victim cable tray while varying the distances between cable trays and architectural surfaces. The results of this study provide geometrical information on the placement of open cable trays to avoid electromagnetic interference problems.

Matched Field Source Localization and Interference Suppression Using Mode Space Estimation (정합장 기반 표적 위치추정 시 모드공간 분석을 통한 간섭 신호 제거 기법)

  • Kim, Kyung-Seop;Seong, Woo-Jae;Pyo, Sang-Woo
    • The Journal of the Acoustical Society of Korea
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    • v.27 no.1
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    • pp.40-46
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    • 2008
  • Weak target detection and localization in the presence of loud surface ship noise is a critical problem for matched field processing (MFP) in shallow water. For stationary sources, each signal component of received signal can be separated and interference can be suppressed using eigen space analysis schemes. However, source motion, in realistic cases, causes spreading of signal energies in their subspace. In this case, eigenvalues of target and interfere signal components are mixed and hard to be separated with usual phone space eigenvector decomposition (EVD) approaches. Our technique is based on mode space and utilizes the difference in their physical characteristics of surface and submerged sources. Performing EVD for modal cross spectral density matrix, interference components in the mode amplitude subspace can be classified and eliminated. This technique is demonstrated with synthetic data, and results are discussed.