Kurum Yazarı "Türkay, Semiha" WoS İndeksli Yayınlar Koleksiyonu İçin Listeleme
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Power spectrum estimation with missing values
Akçay, Hüseyin; Türkay, Semiha (IEEE, 2015)In this paper, we consider estimation of a power spectrum from noise corrupted spectrum samples on uniform grids of frequencies with missing values. A scheme based on regularized nuclear norm optimization and subspace ... -
Rail Track Modelling by Using Identification and Curve Fitting Techniques
Türkay, Semiha; Leblebici, Aslı Soyic; Akçay, Hüseyin (IEEE, 2018)In this paper, a seventeen-degree-of-freedom full-car model of a high speed railway vehicle excited by real track profile is going to be studied. The field measurements are collected by Turkish State Railways (TCDD) on a ... -
Regularized Nuclear Norm Spectrum Estimation in Frequency Domain
Akçay, Hüseyin; Türkay, Semiha (IEEE, 2013)Subspace-based methods have been effectively used to estimate multi-input/multi-output, discrete-time, linear-time invariant systems from spectrum samples. A critical step in these methods is the splitting of causal and ... -
RMS Performance Limitations and Constraints for Quarter-Car Active Suspensions
Akçay, Hüseyin; Türkay, Semiha (IEEE, 2008)In this paper, performance limitations and constraints for an actively controlled quarter-car model subject to white or colored-noise velocity road inputs are investigated. It is demonstrated that tire damping by coupling ... -
Road Profile Modeling by Subspace Identification Methods
Türkay, Semiha; Akçay, Hüseyin (IEEE, 2015)In this paper, spectral models of road profiles using nonparametric and subspace identification methods are developed from road elevation measurements. First, power spectra of road profiles are estimated on uniform grids ... -
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 ... -
Road Roughness Modelling by Using Spectral Factorization Methods
Türkay, Semiha; Akçay, Hüseyin (IEEE, 2016)In this paper, road roughness model for the right and the left tracks are constructed by utilizing two methods. In the first method, from time-domain measurements the empirical auto and cross-power spectral densities of ... -
A spectral estimation case study in frequency-domain by subspace methods
Akçay, Hüseyin; Türkay, Semiha (IEEE, 2013)In this paper, the properties of two recently proposed frequency-domain subspace-based algorithms to estimate discrete-time cross-power spectral density (cross-PSD) and auto-power spectral density (auto-PSD) matrices of ... -
Spectral Modeling of Longitudinal Road Profiles
Türkay, Semiha; Akçay, Hüseyin (IEEE, 2015)In this paper, for a quarter-car model, we derive covariance expressions for the MIRA spectrum and calculate the root-mean square outputs for the ISO 8608 classified roads. The derived results are compared with existing ... -
Spectrum estimation in innovation models by a nuclear norm optimization based algorithm
Akçay, Hüseyin; Türkay, Semiha (IEEE, 2017)In this paper, identification of multi-input/multioutput (Ml MO) state-space models in the innovation form by a regularized-nuclear norm optimization based subspace algorithm is studied. Parametrization issues arc carefully ... -
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 ... -
Stochastic Models for Parallel Road Tracks
Türkay, Semiha; Akçay, Hüseyin (IEEE, 2016)In this paper, we propose a method for constructing road roughness on parallel tracks. This method uses empirical power spectral densities and coherence of the left and the right-tracks estimated by non-parametric methods. ... -
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 ... -
A subspace-based approach to Lagrange-Sylvester interpolation of rational matrix functions
Akçay, Hüseyin; Türkay, Semiha (IEEE, 2005)In this paper, we study 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. As ... -
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 real or imaginary parts of frequency-response data
Akçay, Hüseyin; Türkay, Semiha (IEEE, 2009)In this paper, 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 ... -
Subspace-Based Spectrum Estimation By Nuclear Norm Minimization
Akçay, Hüseyin; Türkay, Semiha (IEEE, 2013)Subspace-based methods have been effectively used to estimate multi-input/multi-output, linear-time-invariant systems from noisy spectrum samples. In these methods, a critical step is splitting of two invariant subspaces ... -
Subspace-based spectrum estimation by reweighted and regularized nuclear norm minimization in frequency-domain
Akçay, Hüseyin; Türkay, Semiha (IEEE, 2015)In this paper, we study model order choice in subspace-based identification algorithms using nonuniformly spaced spectrum measurements. A critical step in these methods is splitting of two invariant subspaces associated ... -
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 ...