• Title/Summary/Keyword: Periodic nonuniformity

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Uniformity Optimization of TFTs Fabricated on 2-shot SLS-Processed Si Films

  • Turk, Brandon A.;Wilt, P.C. Van Der;Crowder, M.A.;Voutsas, A.T.;Limanov, A.B.;Chung, U.J.;Im, James S.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.1750-1755
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    • 2006
  • Nonoptimal placement of short-channel-length TFTs in large-grained polycrystalline Si films with a periodic microstructure, as for instance obtained via 2-shot SLS, can potentially lead to degradation in the overall uniformity of the resultant devices. In this paper, we explain and demonstrate that by simply introducing a well-defined misorientation between the devices and the periodic microstructure, it is possible to significantly reduce (and potentially entirely eliminate) the device nonuniformity problem that can arise from such a cause.

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Propagation of Structural Waves along Waveguides with Non-Uniformities Using Wavenumber Domain Finite Elements (국부적 불연속을 갖는 도파관을 따라 전파되는 파동에 대한 파수 영역 유한 요소 해석)

  • Ryue, Jungsoo
    • The Journal of the Acoustical Society of Korea
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    • v.33 no.3
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    • pp.191-199
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    • 2014
  • Wave reflection and transmission characteristics in waveguides are an important issue in many engineering applications. A combined spectral element and finite element (SE/FE) method is used to investigate the effects of local non-uniformities but limited at relatively low frequencies because the SE is formulated by using a beam theory. For higher frequency applications, a method named a combined spectral super element and finite element (SSE/FE) method was presented recently, replacing spectral elements with spectral super elements. This SSE/FE approach requires a long computing time due to the coupling of SSE and FE matrices. If a local non-uniformity has a uniform cross-section along its short length, the FE part could be further replaced by SSE, which improves performance of the combined SSE/FE method in terms of the modeling effort and computing time. In this paper SSEs are combined to investigate the characteristics of waves propagating along waveguides possessing geometric non-uniformities. Two models are regarded: a rail with a local defect and a periodically ribbed plate. In the case of the rail example, firstly, the results predicted by a combined SSE/FE method are compared with those from the combined SSEs in order to justify that the combined SSEs work properly. Then the SSEs are applied to a ribbed plate which has periodically repeated non-uniformities along its length. For the ribbed plate, the propagation characteristics are investigated in terms of the propagation constant.