73,223 research outputs found

    A new Truncated Fourier Transform algorithm

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    Truncated Fourier Transforms (TFTs), first introduced by Van der Hoeven, refer to a family of algorithms that attempt to smooth "jumps" in complexity exhibited by FFT algorithms. We present an in-place TFT whose time complexity, measured in terms of ring operations, is comparable to existing not-in-place TFT methods. We also describe a transformation that maps between two families of TFT algorithms that use different sets of evaluation points.Comment: 8 pages, submitted to the 38th International Symposium on Symbolic and Algebraic Computation (ISSAC 2013

    On the transconductance of polysilicon thin film transistors

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    In order to achieve both driver and display capability for a number of display devices, TFT has attracted attention, model calculations are therefore presented for the grain boundary barrier height, in a polysilicon TFT considering the charge neutrality between the intrinsic free carriers and the grain boundary trap states. The formation of the potential barrier at a grain boundary is considered due to the trapping of carriers at the localized grain boundary trap states. The trapped charges, influenced by the gate bias voltage and the trapping states density, in turn, have been taken to deplete free carriers near the grain boundary in a device such as polysilicon TFT. The present predictions reveal that the barrier height diversely depends on the gate source voltage (VGS) of a TFT along with other crystal parameter. Finally to obtain the transconductance, the contributions of transverse and longitudinal grain boundary resistances are incorporated in the I-V characteristics of a TFT. For all values of grain size, the transconductance of the device is seen to increase initially with the gate voltage (VGS) which finally appears to be saturated. The dependence of the transconductance on grain size and drain voltage has been thoroughly explored. Good agreement with experimental results is achieved. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2299

    Fatigue testing of low-cost fiberglass composite wind turbine blade materials

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    The static and fatigue behavior of transverse filament tape (TFT) fiberglass/epoxy and TFT/polyester composites was established by the testing of specimens cut from panels fabricated by a filament winding process used for the construction of large experimental wind turbine blades

    Three dimensional field theories from infinite dimensional lie algebras

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    A procedure for constructing topological actions from centrally extended Lie groups is introduced. For a \km\ group, this produces \3al \cs, while for the \vir\ group the result is a new \3al \tft\ whose physical states satisfy the \vir\ \wi. This \tft\ is shown to be a first order formulation of two dimensional induced gravity in the chiral gauge. The extension to W3W_3-gravity is discussed.Comment: 11 pages, USC-92/01

    A-models in three and four dimensions

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    We introduce and study a new 3d Topological Field Theory which can be associated to any compact real manifold X. This TFT is analogous to the 2d A-model and reduces to it upon compactification on an interval with suitable boundary conditions. It plays a role in 3d mirror symmetry as well as in the physical approach to the geometric Langlands duality. A similar TFT can be defined in four dimensions.Comment: 16 pages, late
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