• 제목/요약/키워드: Electronic state

검색결과 3,087건 처리시간 0.036초

Collision-Induced Electronic Relaxation of Thiophosgene (S₁)

  • 김택수;Choi, Young S.
    • Bulletin of the Korean Chemical Society
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    • 제17권8호
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    • pp.745-749
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    • 1996
  • Fluorescence from the electronically excited thiophosgene (Cl2CS) in its first excited singlet state (S1) is efficiently quenched by collision. Rates of the collision-induced electronic relaxation were obtained for various vibrational levels in the S1 state by measuring the fluorescence lifetimes. We found that the relaxation process is strongly energy-dependent; the rate consistently increases by a factor of ~40 with the increase of vibrational energy from 0 to 1450 cm-1. Collision-induced intersystem crossing from the S1 to the first triplet state (T1) is attributed to the major process responsible for the electronic relaxation.

Robust H\ulcorner Control for Delayed System with Time-Varying Norm-Bounded Parameter Uncertainty

  • Kim, Jong-Hae;Jeung, Eun-Tae;Park, Hong-Bea
    • Journal of Electrical Engineering and information Science
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    • 제1권2호
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    • pp.33-38
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    • 1996
  • In this paper, we present a robust H\ulcorner control design method for parameter uncertain systems that have delay in both state and control input. Through a certain algebraic Riccati inequality approach, a state feedback controller is obtained. The proposed state feedback controller stabilizes parameter uncertain delay systems and guarantees disturbance attenuation within a prescribed level. An illustrative example is given to demonstrate the results of the proposed method.

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STEADY-STATE OPTIMIZATION OF AN INTERNAL COMBUSTION ENGINE FOR HYBRID ELECTRIC VEHICLES

  • Wang, F.;Zhang, T.;Yang, L.;Zhuo, B.
    • International Journal of Automotive Technology
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    • 제8권3호
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    • pp.361-373
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    • 2007
  • In previous work, an approach based on maximizing the efficiency of an internal combustion engine while ignoring the power conversion efficiency of other powertrain components, such as the electric motor and power battery or ultracapacitor, was implemented in the steady-state optimization of an internal combustion engine for hybrid electric vehicles. In this paper, a novel control algorithm was developed and successfully justified as the basis for maximal power conversion efficiency of overall powertrain components. Results indicated that fuel economy improvement by 3.9% compared with the conventional control algorithm under China urban transient-state driving-cycle conditions. In addition, using the view of the novel control algorithm, maximal power generation of the electric motor can be chosen.

Y이 도핑된 ZnO의 전자상태 계산 (Calculation on Electronic State of Y-doped ZnO)

  • 이동윤;이원재;송재성;구보근;김현주
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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    • pp.172-173
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    • 2005
  • The electronic state of ZnO doped with Y was calculated using the density functional theory. In this study, the program used for the calculation on theoretical structures of ZnO and doped ZnO was Vienna Ab-initio Simulation Package (VASP), which is a sort of pseudo potential method. The detail of electronic structure was obtained by the descrite variational $X\alpha$ (DV-$X\alpha$) method, which is a sort of molecular orbital full potential method. The optimized crystal structures obtained by calculations were compared to the measured structure. The density of state and energy levels of dopant elements was shown and discussed in association with optical properties.

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On-State Resistance Instability of Programmed Antifuse Cells during Read Operation

  • Han, Jae Hwan;Lee, Hyunjin;Kim, Wansoo;Yoon, Gyuhan;Choi, Woo Young
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제14권5호
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    • pp.503-507
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    • 2014
  • The on-state resistance ($R_{ON}$) instability of standard complementary metal-oxide-semiconductor (CMOS) antifuse cells has been observed for the first time by using acceleration factors: stress current and ambient temperature. If the program current is limited, the $R_{ON}$ increases as time passes during read operation.

Steady-State Analysis of Reactance Oscillators having Multiple Oscillations

  • Matsuo, K.;Matsuda, T.;Nishio, Y.;Yamagami, Y.;Ushida, A.
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2000년도 ITC-CSCC -1
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    • pp.203-206
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    • 2000
  • In this paper, we discuss an efficient steady-state analysis of reactance oscillators having multiple oscillations. Our oscillator is consisted of the Cauer or Foster reactance sub-circuit and a negative resistor such as tunnel diode. The reactance circuit has many resonance and antiresonance points on the frequency response curve. Such a circuit having the specified resonance and anti-resonance points can be easily synthesized with the fundamental circuit theory. In this case, the multiple oscillations may occur near at the anti-resonance points. We have developed a user friendly simulator for getting the exact steady state responses using the SPICE.

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웨이브렛 변환과 파워 스펙트럼 분석을 이용한 EEG의 안정 상태 인식에 관한 고찰 (Recognition of Stable State of EEG using Wavelet Transform and Power Spectrum Analysis)

  • 김영서;길세기;임선아;민홍기;허웅;홍승홍
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2006년도 하계종합학술대회
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    • pp.879-880
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    • 2006
  • The subject of this paper is to recognize the stable state of EEG using wavelet transform and power spectrum analysis. An alpha wave, showed in stable state, is dominant wave for a human EEG and a beta wave displayed excited state. We decomposed EEG signal into an alpha wave and a beta wave in the process of wavelet transform. And we calculated each power spectrum of EEG signal, an alpha wave and a beta wave using Fast Fourier Transform. We recognized the stable state by making a comparison between power spectrum ratios respectively.

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자동차 헤드라이트용 전자식 안정기 개발 (Development of Electronic Ballast for Automotive High Intensity Discharge Lamp)

  • 박종연;배수호;조계현
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2002년도 하계종합학술대회 논문집(5)
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    • pp.319-322
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    • 2002
  • In this Paper, we suggested the Half-Bridge inverter for the automotive HID electronic ballast. electronic ballast for automotive HID lamp should be supplied by low-frequency square wave avoiding the acoustic resonance(11kHz ∼ 825kHz). When the HID lamp is hot state, the electronic ballast should supply the sufficient current for a few milli-second to the lamp at the re-strike ignition state. that is called take-over current. We have introduced the new take-over current control method that could have reduced the peak current and supplied the sufficient take-over current.

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