• 제목/요약/키워드: Characteristic variation

검색결과 1,459건 처리시간 0.028초

Study of Non-uniform Plasma Layer Variation with Optically-Controlled Microwave Pulses

  • Wang, Xue;Yun, Ji-Hun;Kim, Yong-K.
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2009년도 하계학술대회 논문집
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    • pp.90-91
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    • 2009
  • We study of the variation on non-uniform plasma in different layer of the semiconductor. The transient response in different plasma layer has been evaluated theoretically. The reflection function of dielectric microstrip lines resulting from the presence of plasma are evaluated by the transmission line model. The diffusion length is small compared to the absorption depth. The variation of characteristic response in plasma layer with microwave pulses which has in localized has been evaluated.

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Study of FFF with Optically-Controlled Microwave Pulses in Non-uniform Plasma Layer

  • Wang, Xue;Seo, Dong-Ho;Kim, Yong-K.
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2009년도 하계학술대회 논문집
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    • pp.149-150
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    • 2009
  • In this paper we study on the semiconductor characteristic by calculating the variation of reflection function in microstrip lines, which has open-ended termination containing an optically induced plasma region. The variation of impedances resulting from the presence of plasma has evaluated with time and frequency domain. The responses have been also evaluated theoretically for changing the phase of the variation in the reflection.

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1 - 5 Micron Spectra of Titan: The Spectral and Altitudinal Variation of Haze

  • Kim, Sang-Joon
    • 천문학회보
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    • 제39권2호
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    • pp.96.2-96.2
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    • 2014
  • Using solar occultation data obtained by Cassini/Visual Infrared Mapping Spectrometer (VIMS), we were able to retrieve the 1 - 5 mm optical-depth spectra of the Titanian haze, for which only selected wavelength and altitudinal ranges were previously analyzed. We found that the gross 1 - 5 mm shapes of the retrieved haze spectra are significantly different from the spectra of tholin samples in the literature. We also derived the vertical variation of the spectral structure of the $3.3-3.4{\mu}m$ absorption feature of the Titan haze from the VIMS data recorded between 250 and 700 km altitude. We found a marked change between 480 and 580 km in the relative amplitudes of the 3.33 and $3.38{\mu}m$ features which are characteristic of aromatic (double C=Cchains or rings) or aliphatic (single C-C chains) structural groups, respectively. Dicussions on this spectral and altitudinal variation will be presented.

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Vibration analysis of a shear deformed anti-symmetric angle-ply conical shells with varying sinusoidal thickness

  • Javed, Saira;Viswanathan, K.K.;Aziz, Z.A.;Lee, J.H.
    • Structural Engineering and Mechanics
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    • 제58권6호
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    • pp.1001-1020
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    • 2016
  • The study is to investigate the free vibration of antisymmetric angle-ply conical shells having non-uniform sinusoidal thickness variation. The arbitrarily varying thickness is considered in the axial direction of the shell. The vibrational behavior of shear deformable conical shells is analyzed for three different support conditions. The coupled differential equations in terms displacement and rotational functions are obtained. These displacement and rotational functions are invariantly approximated using cubic spline. A generalized eigenvalue problem is obtained and solved numerically for an eigenfrequency parameter and an associated eigenvector of spline coefficients. The vibration characteristic of the shells is examined for cone angle, aspect ratio, sinusoidal thickness variation, layer number, stacking sequence, and boundary conditions.

예압에 따른 압전 변환기의 공진특성 변화 (Variation in the Vibration Characteristics of a Piezoelectric Transducer due to Pre-pressure)

  • 김대승;김진오
    • 한국소음진동공학회논문집
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    • 제16권1호
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    • pp.89-100
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    • 2006
  • This paper presents an analytical approach to describe the variation in the vibration characteristics such as the natural frequency of a piezoelectric transducer under static pre-pressure. The transducer considered in this paper is a bolt-clamped Langevin-type transducer, which consists of a couple of piezoelectric discs, a couple of metal blocks for added mass effect, and a bolt to tighten them. A new analysis model for the transducer has been developed by taking into account the contact area between the piezoelectric ceramic disc and the metal block. The variation of the resonance frequency due to the pre-pressure has been calculated and compared with measured results reported earlier.

정원등(lanterns)용 태양전지셀의 온도특성 변화연구 (A study on characteristic variation of solar cells for lanterns as a temperature change)

  • 이세현;박창용;조미령;신상욱;황명근;양승용
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년도 제37회 하계학술대회 논문집 B
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    • pp.1199-1200
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    • 2006
  • In this paper, I try to measure the electrical characteristics of PV cell for lanterns with solar simulator and simulated with PC1D software. I keep my eye on the characteristics variation of PV cell as a temperature change. Therefore, I try to increase a temperature of controlled block from $10^{\circ}C$ to $50^{\circ}C$ while measuring the PV cell. As a result, A variation caused by voltage have an effect on the efficacy of PV cell. Hence, it is an important variable when a designer plan to make a solar cell for lanterns.

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능동판토그래프의 저차제어기 설계 (A Low-Order Controller Design of Active Pantograph System)

  • 백승구;장석각;권성태;김진환
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2009년도 춘계학술대회 논문집
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    • pp.940-945
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    • 2009
  • This paper presents the design method of low order controller for the active pantograph of electric train system. The pantograph is the most playa role to supply constant current to the train. The design objectives are to have good tracking performance about reference contact force despite the stiffness variation that is like sinusoidal function concerned in train speed or span length of contact wire. In this paper, we consider stiffness variation from external disturbance of active pantograph to simplify model equation, and propose simple second-order controller which is designed by Characteristic ratio assignment(CRA) control method. Finally, we verify time response appling to model equation of real system and frequency response about parameter uncertainty like stiffness variation. it is performed by Matlab version 6.5 and Matlab simulink simulation.

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열차의 속도 하중을 고려한 강우시 성토사면의 안정성 변화 (Variation of Slope Stability under rainfall considering Train Speed)

  • 김정기;김현기;박영곤;신민호;김수삼
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2002년도 추계학술대회 논문집(I)
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    • pp.601-607
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    • 2002
  • Infiltration of rainfall causes railway embankment to be unstable and may result in failure. Basic relationship between the stability of railway embankment and rainfall introducing the partial saturation concept of ground are defined to analyze the stability of embankment by rainfall. A pressure plate test is also peformed to obtain soil-water characteristic curve of unsaturated soils. Based on this curve, the variables in the shear strength function and permeability function are also defined. These functions are used fur the numerical model for evaluation of railway embankments under rainfall. As comparing the model and case studies, the variation of shear strength, the degree of saturation and pore-water pressure for railway embankment during rainfall can be predicted and the safety factor of railway embankment can be expressed as the function of rainfall amount namely rainfall index. Therefore, the research on safety factor on railway embankment considering train speed and rainfall infiltration with the variation of rainfall intensity and rainfall duration was carried out in this paper.

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