Now showing items 1-12 of 12

    • An audio watermarking algorithm via zero assigned filter banks 

      Yücel, Zeynep; Özgüler, A. Bülent (IEEE, 2005)
      In order to identify the owner and distributor of digital data, a watermarking scheme for audio files is proposed in frequency domain. The scheme satisfies the imperceptibility and persistence requirements and is robust ...
    • Equiripple FIR filter design by the FFT algorithm 

      Çetin, A. E.; Gerek, Ö. N.; Yardımcı, Y. (Institute of Electrical and Electronics Engineers, 1997-03)
      The fast Fourier transform (FFT) algorithm has been used in a variety of applications in signal and image processing. In this article, a simple procedure for designing finite-extent impulse response (FIR) discrete-time ...
    • Fabrication of high-speed resonant cavity enhanced schottky photodiodes 

      Özbay, Ekmel; Islam, M. S.; Onat, B.; Gökkavas, M.; Aytür, O.; Tuttle, G.; Towe, E.; Henderson, R. H.; Ünlü, M. S. (Institute of Electrical and Electronics Engineers, 1997-05)
      We report the fabrication and testing of a GaAs-based high-speed resonant cavity enhanced (RCE) Schottky photodiode. The top-illuminated RCE detector is constructed by integrating a Schottky contact, a thin absorption ...
    • Frequency responses of ground-penetrating radars operating over highly lossy grounds 

      Oğuz, U.; Gürel, L. (IEEE, 2002)
      The finite-difference time-domain (FDTD) method is used to investigate the effects of highly lossy grounds and the frequency-band selection on ground-penetrating-radar (GPR) signals. The ground is modeled as a heterogeneous ...
    • A new directional acoustic lens: V-groove lens 

      Bozkurt, Ayhan; Yaralıoğlu, G. Göksenin; Atalar, Abdullah; Köymen, Hayrettin (IEEE, 1993)
      A new directional acoustic lens is introduced. The geometry is very similar to the line-focus lens except the lens cavity, which is shaped as a groove with flat-bottom V cross section. The slanted planar edges of the groove ...
    • On approximation sums by maximums and vice versa 

      Ozaktas, H. M. (SAGE, 1994)
      We discuss the approximation max (x, y) ≈x+y for x, y >0, which is found to be useful in obtaining simple and transparent approximate solutions and interpretations for analytically complicated problems.
    • On reduced order modeling of flexible structures from frequency response data 

      Demir, Okan; Özbay, Hitay (IEEE, 2014)
      In order to identify the dominant flexible modes of a flexible structure with an input/output delay, a numerical method is proposed. The method uses a frequency domain approach (frequency response data) to estimate the ...
    • Rayleigh-bloch waves in CMUT arrays 

      Atalar, Abdullah; Köymen, H.; Oğuz, H. K. (Institute of Electrical and Electronics Engineers Inc., 2014)
      Using the small-signal electrical equivalent circuit of a capacitive micromachined ultrasonic transducer (CMUT) cell, along with the self and mutual radiation impedances of such cells, we present a computationally efficient ...
    • Reduced order modeling of infinite dimensional systems from frequency response data 

      Demir, Okan (Bilkent University, 2014)
      In this thesis, a system identification method using frequency response data is studied. Identification method is applied to various types of distributed parameter systems, in particular flexible structures. One of the ...
    • Sub-band equalization filter design for improving dynamic range performance of modulated wideband converter 

      Alp, Y. K.; Gök, Gökhan; Korucu, A. B. (IEEE, 2017)
      In this work, we propose an iterative method to improve the dynamic range performance of the Modulated Wideband Converter (MWC), which is multi-channel sampling system for digitizing wideband sparse signals below the Nyquist ...
    • Sub-band equalization of modulated wideband converter for improved dynamic range performance 

      Korucu, A. B.; Alp, Y. K.; Gök, Gökhan; Arıkan, Orhan (IEEE, 2017)
      In this work, we propose a new method to improve the dynamic range performance of the Modulated Wideband Converter (MWC), which is multi-channel sampling system for digitizing wideband sparse signals below the Nyquist limit ...
    • Ultrafast and highly efficient resonant cavity enhanced photodiodes 

      Özbay, Ekmel; Kimukin, İbrahim; Bıyıklı, Necmi (SPIE, 2003-09)
      In this talk, we will review our research efforts on resonant cavity enhanced (RCE) high-speed high-efficiency photodiodes (PDs) operating in the 1st and 3rd optical communication windows. Using a microwave compatible ...