Now showing items 1-20 of 21

    • Adaptive filtering approaches for non-Gaussian stable processes 

      Arıkan, O.; Belge, M.; Çetin, A. E.; Erzin, E. (Institute of Electrical and Electronics Engineers, 1995)
      A large class of physical phenomenon observed in practice exhibit non-Gaussian behavior. In this paper, α-stable distributions, which have heavier tails than Gaussian distribution, are considered to model non-Gaussian ...
    • Adaptive methods for dithering color images 

      Akarun, L.; Yardımcı, Y.; Çetin, A. E. (Institute of Electrical and Electronics Engineers, 1997-07)
      Most color image printing and display devices do not have the capability of reproducing true color images. A common remedy is the use of dithering techniques that take advantage of the lower sensitivity of the eye to spatial ...
    • Cumulant based identification approaches for nonminimum phase FIR systems 

      Alshebeili, S. A.; Venetsanopoulos, A. N.; Çetin, A. E. (IEEE, 1993)
      In this paper, recursive and least squares methods for identification of nonminimum phase linear time-invariant (NMP-LTI) FIR systems are developed. The methods utilize the second- and third-order cumulants of the output ...
    • Cumulant-based parametric multichannel FIR system identification methods 

      Özgen, M. T.; Alshebeili, S. A.; Çetin, A. E.; Venetsanopoulos, A. N. (Elsevier, 1994)
      In this paper, “least squares” and recursive methods for simultaneous identification of four nonminimum phase linear, time-invariant FIR systems are presented. The methods utilize the second- and fourth-order cumulants of ...
    • Efficient evaluation of spatial-domain MoM matrix entries in the analysis of planar stratified geometries 

      Kinayman, N.; Aksun, M. I (IEEE, 2000)
      An efficient hybrid method for evaluation of spatial-domain method-of-moments (MoM) matrix entries is presented in this paper. It has already been demonstrated that the introduction of the closed-form Green's functions ...
    • Enhancements to linear least squares localization through reference selection and ML estimation 

      Guvenc I.; Gezici, S.; Watanabe F.; Inamura H. (2008)
      Linear least squares (LLS) estimation is a low complexity but sub-optimum method for estimating the location of a mobile terminal (MT) from some distance measurements. It requires selecting one of the fixed terminals (FTs) ...
    • LMS based adaptive prediction for scalable video coding 

      Toreyin, B.U.; Trocan, M.; Pesquet-Popescu, B.; Cetin, A.E. (2006)
      3D video codecs have attracted recently a lot of attention, due to their compression performance comparable with that of state-of-art hybrid codecs and due to their scalability features. In this work, we propose a least ...
    • Lossless image compression by LMS adaptive filter banks 

      Öktem, R.; Çetin, A. E.; Gerek, O. N.; Öktem, L.; Egiazarian, K. (Elsevier, 2001)
      A lossless image compression algorithm based on adaptive subband decomposition is proposed. The subband decomposition is achieved by a two-channel LMS adaptive filter bank. The resulting coefficients are lossy coded first, ...
    • On the performance of linear least-squares estimation in wireless positioning systems 

      Gezici, S.; Guvenc I.; Sahinoglu, Z. (2008)
      A common technique for wireless positioning is to estimate time-of-arrivals (TOAs) of signals traveling between a target node and a number of reference nodes, and then to determine the position of the target node based on ...
    • Optimization of F2 layer parameters using IRI-Plas and IONOLAB-TEC 

      Şahin O.; Sezen, U.; Arikan F.; Arikan, O. (2011)
      In this study, the relation of the maximum ionization height (HmF2) and the critical frequency (FoF2) of F2 layer is examined within their parametric range through the International Reference Ionosphere extended towards ...
    • Optimization of F2 layer parameters using IRI-Plas model and IONOLAB Total Electron Content 

      Sahin O.; Sezen, U.; Arikan F.; Arikan, O.; Aktug, B. (2011)
      In this study, the relation of the maximum ionization height (HmF2) and the critical frequency (FoF2) of F2 layer is examined within their parametric range through the International Reference Ionosphere extended towards ...
    • Parallel minimum norm solution of sparse block diagonal column overlapped underdetermined systems 

      Torun, F. S.; Manguoglu, M.; Aykanat, C. (Association for Computing Machinery, 2017)
      Underdetermined systems of equations in which the minimum norm solution needs to be computed arise in many applications, such as geophysics, signal processing, and biomedical engineering. In this article, we introduce a ...
    • QR-RLS algorithm for error diffusion of color images 

      Unal, G. B.; Yardimci, Y.; Arikan, O.; Çetin, A. E. (SPIE, 2000)
      Printing color images on color printers and displaying them on computer monitors requires a significant reduction of physically distinct colors, which causes degradation in image quality. An efficient method to improve the ...
    • Range based sensor node localization in the presence of unknown clock skews 

      Gholami, M.R.; Gezici, S.; Strom, E.G. (2013)
      We deal with the positioning problem based on two-way time-of-arrival (TW-TOA) measurements in asynchronous wireless sensor networks. The optimal estimator for this problem poses a difficult global optimization problem. ...
    • Recovery of sparse perturbations in Least Squares problems 

      Pilanci, M.; Arikan, O. (2011)
      We show that the exact recovery of sparse perturbations on the coefficient matrix in overdetermined Least Squares problems is possible for a large class of perturbation structures. The well established theory of Compressed ...
    • Robust least squares methods under bounded data uncertainties 

      Vanli, N. D.; Donmez, M. A.; Kozat, S. S. (Academic Press, 2015)
      We study the problem of estimating an unknown deterministic signal that is observed through an unknown deterministic data matrix under additive noise. In particular, we present a minimax optimization framework to the least ...
    • Solution and cost analysis of general multi-channel and multi-stage filtering circuits 

      Kutay, M. A.; Arikan, O.; Özaktaş, H. M.; Erden, M. F.; Özaktaş, H. (IEEE, Piscataway, NJ, United States, 1998)
      The fractional Fourier domain multi-channel and multi-stage filtering configurations that have been recently proposed enable us to obtain either exact realizations or useful approximations of linear systems or matrix-vector ...
    • Static positioning using UWB range measurements 

      Gholami, M.R.; Ström, E.G.; Sottile F.; Dardari, D.; Conti, A.; Gezici, S.; Rydström, M.; Spirito, M.A. (2010)
      The performance of several existing and partly new algorithms for positioning of sensor node based on distance estimate is compared when the distance estimates are obtained from a measurement campaign. The distance estimates ...
    • Theoretical limits and a practical estimator for joint estimation of respiration and heartbeat rates using UWB impulse radio 

      Gezici, S.; Ankan O. (2007)
      In this paper, Cramer-Rao lower bounds are derived fo r joint estimation of respiration and heartbeat rates via impulse radio ultra-wideband signals. Generic models are employed for displacement functions due to respiration ...
    • Theoretical limits for estimation of vital signal parameters using impulse radio UWB 

      Gezici, S.; Sahinoglu, Z. (2007)
      In this paper, Cramer-Rao lower bounds (CRLBs) for estimation of vital signal parameters, such as respiration and heart-beat rates, using ultra-wideband (UWB) pulses are derived. In addition, a simple closed-form CRLB ...