Now showing items 1-11 of 11

    • An adaptive speckle suppression filter for medical ultrasound imaging 

      Karaman, M.; Kutay, M. A.; Bozdagi, G. (Institute of Electrical and Electronics Engineers, 1995-06)
      An adaptive smoothing technique for speckle suppression in medical B-scan ultrasonic imaging is presented. The technique is based on filtering with appropriately shaped and sized local kernels. For each image pixel, a ...
    • Chirp filtering in the fractional Fourier domain 

      Dorsch, R. G.; Lohmann, A. W.; Bitran, Y.; Mendlovic, D.; Haldun M. Özaktaş (Optical Society of America, 1994-11-10)
      In the Wigner domain of a one-dimensional function, a certain chirp term represents a rotated line delta function. On the other hand, a fractional Fourier transform (FRT) can be associated with a rotation of the ...
    • A comparative performance analysis for the commonly used time series filters in economics : Hodrick-Prescott versus Baxter-King 

      Yüksel, Ebru (Bilkent University, 2001)
      This thesis compares the performance of the Hodrick-Prescott filter commonly employed in economic analysis to separate the trend of a given non-stationary time series from its cyclical components, to that of the Band-Pass ...
    • Extensions to common laplace and fourier transforms 

      Onural, L.; Erden, M. F.; Haldun M. Özaktaş (Institute of Electrical and Electronics Engineers, 1997-11)
      The extended versions of common Laplace and Fourier transforms are given. This is achieved by defining a new function fe(p), p 2 C related to the function to be transformed f(t), t 2 R. Then fe(p) is transformed by an ...
    • H∞ filter design for vehicle tracking under delayed and noisy measurements 

      Ezercan, Sami; Özbay, Hitay (IEEE, 2007-06)
      In many intelligent vehicles applications tracking plays an important role. This paper considers tracking of a vehicle under delayed and noisy measurements. For this purpose we design an H∞ optimal filter for linear systems ...
    • On stability of interval matrices 

      Sezer, M. E.; Siljak, D. D. (Institute of Electrical and Electronics Engineers, 1994-02)
      New sufficient, and sometimes necessary and sufficient conditions, are obtained for Schur- and Hurwitz-stability of interval matrices by relying on the concept of connective stability and M-matrices. The necessity part is ...
    • Optimal filtering in fractional Fourier domains 

      Kutay, M. A.; Haldun M. Özaktaş; Arıkan, Orhan (Institute of Electrical and Electronics Engineers, 1997-05)
      For time-invariant degradation models and stationary signals and noise, the classical Fourier domain Wiener filter, which can be implemented in O(N log N) time, gives the minimum mean-square-error estimate of the original ...
    • Past, present, and future on news streams: discovering story chains, selecting public front-pages, and filtering microblogs for predicting public reactions to news 

      Toraman, Çağrı (Bilkent University, 2017-09)
      News streams have several research opportunities for the past, present, and future of events. The past hides relations among events and actors; the present re ects needs of news readers; and the future waits to be ...
    • Right-triangular subdivision for texture mapping ray-traced objects 

      Akdemir, U.; Özgüç, B.; Güdükbay, Uğur; Selçuk, A. (Springer, 1998)
      The introduction of global illumination and texture mapping enabled the generation of high-quality, realistic looking images of computer graphics models. We describe a fast and efficient 2D texture mapping algorithm that ...
    • Texture mapping with ray tracing 

      Akdemir, Uğur (Bilkent University, 1993-10)
      By using texture generation and global illumination techniques, it is possible to produce realistic computer images. Currently, ray tracing is one of the most popular global illumination techniques due to its simplicity, ...
    • A two-stage stochastic programming approach for reliability constrained power system expansion planning 

      Peker, M.; Kocaman, A. S.; Kara, B. Y. (Elsevier, 2018)
      Probabilistic realizations of outages and their effects on the operational costs are highly overlooked aspects in power system expansion planning. Since the effect of randomness in contingencies can be more prominent ...