• Title/Summary/Keyword: Detuning

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Study for the Bragg Detuning Effects on the Transmission Holograms and the Reflection Holograms (투과형 홀로그램과 반사형 홀로그램에서의 Bragg detuning 현상에 대한 연구)

  • Kwon, Yun-Young;Kim, Kun-Yul;Park, Joo-Youn
    • Transactions of the Society of Information Storage Systems
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    • v.2 no.3
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    • pp.189-195
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    • 2006
  • Bragg detuning effect if, one of the serious problems if the photopolymer is used for the recording material of holography memories. And the critical reasons of that are known as the bulk refractive index change and shrinkage of recording material. However, the trials for analyzing the effect are mainly on the K-sphere and biased on the transmission hologram. So, we approached Bragg detuning effect numerically and applied the method to the transmission holograms and the reflection holograms all together. We simulated it with MATLAB. As a result, the bulk refractive index change causes+Bragg detuning effect on the transmission holograms and the reflection holograms. But the shrinkage leads to+Bragg detuning effect on the transmission hologram and-Bragg detuning effect on the reflective hologram. Compared to experimental result, the bulk refractive index change(${\fallingdotseq}4{\times}10^{-4}$) and the ratio of shrinkage to the thickness of the material(${\fallingdotseq}1.67{\times}10^{-3}$) could be matched with Bragg detuning effect on the transmission hologram and the reflection hologram.

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Analysis on Parameter Detuning of Induction Motor Drives in Constant Torque Region (일정토크영역에서 유도전동기 고정자자속기준제어의 파라미터 비동조 영향 분석)

  • Shin, Myoung-Ho
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.26 no.11
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    • pp.81-86
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    • 2012
  • It is well known that the stator-flux-oriented induction motor drives are not dependent on parameter detuning in constant torque region except low speed range. This paper presents parameter detuning effects of stator-flux-oriented induction motor drives in constant torque region. The detuning effects of stator resistance, rotor resistance and rotor leakage inductance are analyzed.

Analysis on Parameter Detuning of Induction Motor Drives in Field Weakening Region (약계자영역에서 유도전동기 고정자자속기준제어의 파라미터 비동조 영향 분석)

  • Shin, Myoung-Ho
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.24 no.9
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    • pp.118-123
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    • 2010
  • The selection of flux level in the maximum torque control of stator flux-oriented induction motor drives in the field weakening region is dependent on stator resistance and inductances. This paper presents parameter detuning effects of stator flux-oriented control drives in the field weakening region. The detuning effects of stator resistance and rotor leakage inductance are analyzed. The decrease of torque and the flux control lost by the detuning of inductance are shown in the simulation results.

Considerations on the Performance of Current Sensorless Control of a Synchronous Reluctance Motor (동기릴럭턴스전동기의 전류센서리스 제어 성능 고찰)

  • Shin, Myoung-Ho
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.26 no.1
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    • pp.61-65
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    • 2012
  • Some works about the current sensorless control of a synchronous reluctance motor have been presented. However, there is no analysis about the performance and the detuning effect of the current sensorless control. This paper presents the problems and the detuning effect of the current sensorless control of a synchronous reluctance motor by simulation results. In addition, torque limiter is proposed to limit the torque current within the torque limit.

Chirping Characteristics Analysis of Electroabsorption Modulators by Riber Transmission Simulations (전송 모의실험을 통한 전계흡수 광변조기의 파장왜곡 특성해석)

  • Han, Sub;Kim, Kyung-Hyun;Han, Sang-Kook
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.35D no.5
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    • pp.93-99
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    • 1998
  • The chirping characteristics of InGaAsP electroabsorption modulatiors have been analyzed. The effective .alpha. parameters for large signal modulation were estimated by comparing the pulse shape after fiber transmission with constant chirping assumption.We investigated the structure and the operating condition of the modulator to improve the chirping characteristics. The .alpha. parameters were calculated as the function of wavelength detuning and the bias voltage. To minimize the chirping performance, high bias voltage and a small wavelength detuning and the bias voltage. To minimize the chirping performance, high bias voltage and a small wavelength detuning were preferred. An negative .alpha. value is achieved at the wavelength detuning below 30meV with a proper bias voltage so that pulse compression effect was expected.

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Non-Lorentzian Resonance Due to the Detuning in One-Color Two-Photon Photodissociation

  • Lee, Seong Yul
    • Bulletin of the Korean Chemical Society
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    • v.21 no.7
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    • pp.712-714
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    • 2000
  • Non-Lorentyian resonance is predicted to occur in two-photon photoabsorption processes due to the detuning off the intermediate levels. This type of non-Lorentzian resonance is distinct from the asymmetric resonance resulting from the effects of q uantum interference between competing indistinguishable dynamic pathways. The product distributions are shown to be constant near this type of resonance.

Analysis of Key Parameters for Inductively Coupled Power Transfer Systems Realized by Detuning Factor in Synchronous Generators

  • Liu, Jinfeng;Li, Kun;Jin, Ningzhi;Iu, Herbert Ho-Ching
    • Journal of Power Electronics
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    • v.19 no.5
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    • pp.1087-1098
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    • 2019
  • In this paper, a detuning factor (DeFac) method is proposed to design the key parameters for optimizing the transfer power and efficiency of an Inductively Coupled Power Transfer (ICPT) system with primary-secondary side compensation. Depending on the robustness of the system, the DeFac method can guarantee the stability of the transfer power and efficiency of an ICPT system within a certain range of resistive-capacitive or resistive-inductive loads. A MATLAB-Simulink model of a ICPT system was built to assess the system's main evaluation criteria, namely its maximum power ratio (PR) and efficiency, in terms of different approaches. In addition, a magnetic field simulation model was built using Ansoft to specify the leakage flux and current density. Simulation results show that both the maximum PR and efficiency of the ICPT system can reach almost 70% despite the severe detuning imposed by the DeFac method. The system also exhibited low levels of leakage flux and a high current density. Experimental results confirmed the validity and feasibility of an ICPT system using DeFac-designed parameters.

Self-Pulsation in Multisection Distributed Feedback Laser Diode with a Novel Dual Grating Structure

  • Park, Kyung-Hyun;Leem, Young-Ahn;Yee, Dae-Su;Baek, Yong-Soon;Kim, Dong-Churl;Kim, Sung-Bock;Sim, Eun-Deok
    • ETRI Journal
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    • v.25 no.3
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    • pp.149-155
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    • 2003
  • A self-pulsating multisection distributed-feedback laser diode (DFB LD) can potentially realize all-optical clock extraction. This device generally consists of three sections, two DFB sections and one waveguide section. The most important variable in this device is detuning, which is the relative spectral position between the stop bands of two DFB sections. We fabricated a novel structure in which two gratings were located one over and one under the active layers. Each grating structure was independently defined in processing so that detuning, which is the prerequisite for self-pulsation, could be easily controlled. Observing various self-pulsating phenomena in these devices under several detuning conditions, we characterized the phenomena as dispersive Q-switching, mode beating, and self-mode-locking.

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Asymmetry of microwave transition signal in a Cs atomic beam frequency standard (광펌핑된 세슘빔원자시계에서 마이크로파 전이신호의 비대칭성)

  • 강훈수;김영기;정혜연;김재필;송석호;김필수;오차환;이호성
    • Proceedings of the Optical Society of Korea Conference
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    • 2000.08a
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    • pp.70-71
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    • 2000
  • 세슘빔 공진기에서 세슘D$_2$ 전이선으로 광펌핑된 원자가 램지공진기에서 마이크로파의 주파수에 따른 초미세준위의 바닥상태간의 원자밀도 전이에 의한 형광 신호의 분포를 펌핑광의 세기에 따라 관측하였다. 펌핑광의 편광방향이 자기장에 나란한 $\pi$편광일 때 각 제만부준위의 마이크로파 전이 신호는 mF=0을 중심으로 $\pm$mF의 신호세기가 대칭적이었으나 펌핑광의 편광 방향이 자기장에 수직인 $\sigma$ $\pm$ 인 경우에는 비대칭적임을 확인하였다. 이것은 펌핑광의 주파수가 세슘빔 공진기에서의 세슘공진주파수에서 detuning이 있는 것에 의한 것으로 예상하였다. 이를 확인하기 위해 원자밀도행렬방정식으로 세슘빔공진기에서 마이크로파 전이신호를 계산하였다. 펌핑광의 세기와 편광방향, detuning에 따른 마이크로파 전이신호의 분포가 실험치와 잘 일치함을 알 수 있었다. 이 연구는 세슘빔 원자공진기에서 펌핑광의 주파수가 세슘공진주파수에 detuning된 정도를 관측할 수 있는 방법을 제시해 준다. (중략)

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