Browsing by Subject "Fourier series"

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    Analysis of an arbitrary profile reflector antenna system having resistive type surface–E-polarization case
    (IEEE, 2006-06) Oǧuzer, T.; Altıntaş, Ayhan; Nosich, A. I.
    The regularized solution is performed for arbitrary shape conic section profile geometry. In this case the reflector surface is taken as made up of resistive type material. The problem is formulated depending on the circular In periodicity and then Fourier series coefficients of the surface current density are obtained. The resultant matrix equation is in the regularized form. Then the various numerical results are obtained for different eccentricity factor of the conic section and the resisitvity of the reflector surface. © 2006 IEEE.
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    Implications of energy conditions on standard static space-times
    (Pergamon Press, 2009) Dobarro, F.; Ünal, B.
    In the framework of standard static space-times, we state a family of sufficient or necessary conditions for a set of physically reasonable energy and convergence conditions in relativity and related theories. We concentrate our study on questions about the sub-harmonicity of the warping function, the scalar curvature map, conformal hyperbolicity, conjugate points and the time-like diameter of this class of space-times. © 2009 Elsevier Ltd. All rights reserved.
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    Parametric identification of Hybrid Linear-Time-Periodic Systems
    (Elsevier B.V., 2016) Uyanık, İ.; Saranlı U.; Morgϋl, Ö.; Ankaralı, M. M.
    In this paper, we present a state-space system identification technique for a class of hybrid LTP systems, formulated in the frequency domain based on input-output data. Other than a few notable exceptions, the majority of studies in the state-space system identification literature (e.g. subspace methods) focus only on LTI systems. Our goal in this study is to develop a technique for estimating time-periodic system and input matrices for a hybrid LTP system, assuming that full state measurements are available. To this end, we formulate our problem in a linear regression framework using Fourier transformations, and estimate Fourier series coefficients of the time-periodic system and input matrices using a least-squares solution. We illustrate the estimation accuracy of our method for LTP system dynamics using a hybrid damped Mathieu function as an example. © 2016