Yazar "Akçay, Hüseyin" için Makale Koleksiyonu listeleme
-
On the existence of a disk algebra basis
Akçay, Hüseyin (Elsevier Science BV, 2000)In this paper, approximation of discrete-time systems by fixed pole orthonormal basis functions is investigated. It is shown that if accumulation points of basis poles do not cover the entire unit circle, then the Fourier ... -
On the uniform approximation of discrete-time systems by generalized Fourier series
Akçay, Hüseyin (IEEE-Inst Electrical Electronics Engineers Inc, 2001)In this paper, model sets for linear time-invariant discrete-time systems spanned by fixed orthonormal bases are studied. It is shown that the Fourier series of the system transfer function with respect to these bases ... -
Paley inequalities for discrete-time rational orthonormal bases
Akçay, Hüseyin (Elsevier Science BV, 2000)In this paper, we derive some inequalities which provide information about the Fourier coefficients of linear-time-invariant discrete-time systems with respect to the bounded rational orthonormal basis functions studied ... -
Power spectrum estimation in innovation models
Akçay, Hüseyin; Türkay, Semiha (Academic Press LTD- Elsevier Science LTD, 2019)In this paper, a regularized nuclear norm minimization-based subspace identification algorithm is proposed to estimate discrete-time power spectra of multi-input/multi-out systems in innovation models from output-only ... -
Rational interpolation of analytic functions from real or imaginary parts of frequency-response data: A subspace-based approach
Akçay, Hüseyin; Türkay, Semiha (2009)In this letter, construction of analytic functions from evaluations of real or imaginary parts on finite subsets of the unit circle is studied. The points in the subsets are not necessarily uniformly spaced as in the most ... -
Road Roughness Evaluation by Curve-Fitting and Subspace-Identification Methods
Türkay, Semiha; Akçay, Hüseyin (Asce-Amer Soc Civil Engineers, 2016)In this paper, for a quarter-car model, root-mean square response variables are calculated for roads classified by the international standard organization, based on the straight-line spectrum models. Covariance expressions ... -
Short-term wind speed forecasting by spectral analysis from long-term observations with missing values
Akçay, Hüseyin; Filik, Tansu (Elsevier Sci LTD, 2017)In this paper, we propose a novel wind speed forecasting framework. The performance of the proposed framework is assessed on the wind speed measurements collected from the five meteorological stations in the Marmara region ... -
Spectral estimation in frequency-domain by subspace techniques
Akçay, Hüseyin (Elsevier Science BV, 2014)In this paper, frequency-domain subspace-based algorithms are proposed to estimate discrete-time cross-power spectral density (cross-PSD) and auto-power spectral density (auto-PSD) matrices from samples of the Welch cross-PSD ... -
Spectrum estimation with missing values: A regularized nuclear norm minimization approach
Akçay, Hüseyin; Türkay, Semiha (World Scientific Publ Co Pte LTD, 2016)In this paper, we consider estimation of a power spectrum from noise corrupted spectrum samples on uniform grids of frequencies with missing values. We propose two schemes based on the regularized nuclear norm minimization ... -
A stochastic analysis of robust estimation algorithms in H-infinity with rational basis functions
Akçay, Hüseyin (John Wiley & Sons LTD, 2002)In this paper, a two-stage nonlinear identification algorithm parameterized in terms of rational basis functions with fixed basis poles is studied when disturbances are subject to mild stochastic assumptions. The two-stage ... -
Stochastic optimal control of truck cabin with active suspension
Akçay, Hüseyin; Türkay, Semiha (Inderscience Enterprises LTD, 2014)In this paper, a three-degree-of-freedom cabin model for a commercial truck is derived to study ride motions of the cabin under random road excitations. First, an active suspension system is designed using the linear-Nqu ... -
A study of random vibration characteristics of the quarter-car model
Türkay, Semiha; Akçay, Hüseyin (Academic Press LTD Elsevier Science LTD, 2005)In this paper, the quarter-car model is used to study the response of the vehicle to profile imposed excitation with randomly varying traverse velocity and variable vehicle forward velocity. Root-mean-square response of ... -
Subspace-Based Identification of Acoustic Noise Spectra in Induction Motors
Akçay, Hüseyin; Germen, Emin (IEEE-Inst Electrical Electronics Engineers Inc, 2015)In this paper, we study the identification of acoustic noise spectra in induction motors by using a recently developed frequency-domain cross-power spectrum estimation algorithm. This algorithm is a noniterative high-resolution ... -
A subspace-based method for solving Lagrange-Sylvester interpolation problems
Akçay, Hüseyin; Türkay, Semiha (Siam Publications, 2007)In this paper, we study the Lagrange-Sylvester interpolation of rational matrix functions which are analytic at infinity, and propose a new interpolation algorithm based on the recent subspace-based identification methods. ... -
Subspace-Based Rational Interpolation of Analytic Functions From Phase Data
Akçay, Hüseyin (IEEE-Inst Electrical Electronics Engineers Inc, 2010)In this paper, two simple subspace-based identification algorithms to identify stable linear-time-invariant systems from corrupted phase samples of frequency response function are developed. The first algorithm uses data ... -
Subspace-based spectrum estimation in frequency-domain by regularized nuclear norm minimization
Akçay, Hüseyin (Elsevier Science BV, 2014)Subspace-based methods have been effectively used to estimate multi-input/multi-output, discrete-time, linear-time-invariant systems from noisy spectrum samples. In these methods, a critical step is splitting of two invariant ... -
Subspace-based spectrum estimation in innovation models by mixed norm minimization
Akçay, Hüseyin; Türkay, Semiha (Pergamon-Elsevier Science LTD, 2019)In this paper, identification of discrete-time power spectra of multi-input/multi-output (MIMO) systems in innovation models from output-only time-domain measurements is considered.A hybrid identification algorithm unifying ... -
Synthesis of complete orthonormal fractional basis functions with prescribed poles
Akçay, Hüseyin (IEEE-Inst Electrical Electronics Engineers Inc, 2008)In this paper, fractional orthonormal basis functions that generalize the well-known fixed pole rational basis functions are synthesized. For a range of noninteger differentiation orders and under mild restrictions on the ... -
Synthesis of complete rational orthonormal bases with prescribed asymptotic order
Akçay, Hüseyin (Pergamon-Elsevier Science LTD, 2001)In this paper, a method to construct complete rational orthonormal model sets with prescribed asymptotic order is presented for continuous-time systems. Two special cases that illustrate the application of the method are ... -
Tire Damping Effect on H-2 Optimal Control of Half-Car Active Suspensions
Türkay, Semiha; Akçay, Hüseyin (Asme-Amer Soc Mechanical Eng, 2010)In this note the root-mean-square response of a half-car model following a random road profile is studied. Road excitation at the front wheel is modeled by a first-order linear shape filter driven by white-noise and the ...