6 sonuçlar
Arama Sonuçları
Listeleniyor 1 - 6 / 6
Yayın Design of optimum nyquist signals based on generalized sampling theory for data communications(IEEE, Piscataway, NJ, United States, 1999-06) Panayırcı, Erdal; Özuğur, Timuçin; Çağlar, HakanA new method is given for the optimal design of bandlimited Nyquist-type signal shapes for data communications, which maximizes its energy in a given time interval. The method is based on the periodically nonuniform sampling (PNS) theory making use of the linear splines. The computation is straightforward, and the constraint for intersymbol interferrence is shown to be easy to include in the problem. A numerical example is given, and performance of the optimal signal shapes is compared with that resulting from the use of previously obtained signal shapes in the literature. It is also concluded that the optimal signal shapes thus obtained are almost immune to small offsets at the sampling instants.Yayın Comments on "upper cutoff frequency of the bound wave and new leaky wave on the slotline"(IEEE-INST Electrical Electronics Engineers Inc, 1999-05) İdemen, Mehmet Mithat; Büyükaksoy, İbrahim Alinur[No abstract available]Yayın 3-D spatio-temporal Gabor-type filter implementations with Time-Derivative Cellular Neural Networks(IEEE, 2013) Yavuz, Oğuzhan; Tural Polat, Sadiye Nergis; Cesur, Evren; Tavşanoğlu, Ahmet VedatIn this paper, a 3-D spatio-temporal Gabor-type filter is implemented using Time-Derivative Cellular Neural Network (TDCNN) structure. To this end, the transfer function of the spatio-temporal filter previously constructed by cascading a CNN spatial filter with a temporal filter is shown to be made equal to that of a band-pass filter obtained using a TDCNN structure having first-order temporal derivative diffusion connections only. By equating the coefficients, we obtain the discrete-space Fourier transforms of the TDCNN templates of the Gabor-type band-pass filter. Taking the inverse Fourier transform yields the TDCNN templates. Simulation results are presented.Yayın A numerical study of the long wave-short wave interaction equations(Elsevier B.V., 2007-03-07) Borluk, Handan; Muslu, Gülçin Mihriye; Erbay, Hüsnü AtaTwo numerical methods are presented for the periodic initial-value problem of the long wave-short wave interaction equations describing the interaction between one long longitudinal wave and two short transverse waves propagating in a generalized elastic medium. The first one is the relaxation method, which is implicit with second-order accuracy in both space and time. The second one is the split-step Fourier method, which is of spectral-order accuracy in space. We consider the first-, second- and fourth-order versions of the split-step method, which are first-, second- and fourth-order accurate in time, respectively. The present split-step method profits from the existence of a simple analytical solution for the nonlinear subproblem. We numerically test both the relaxation method and the split-step schemes for a problem concerning the motion of a single solitary wave. We compare the accuracies of the split-step schemes with that of the relaxation method. Assessments of the efficiency of the schemes show that the fourth-order split-step Fourier scheme is the most efficient among the numerical schemes considered.Yayın Feature extraction in shape recognition using segmentation of the boundary curve(Elsevier Science BV, 1997-10) Özuğur, Timuçin; Denizhan, Yağmur; Panayırcı, ErdalWe present a new method for feature extraction of two-dimensional shape information based on segmentation of the boundary curve. This approach partitions closed shapes into segments and finds their angular spans. The number of segments and the angular spans form the first two feature parameters of a given shape. Fourier coefficients of all segments constitute the final feature parameters. The algorithm renders the shapes independent of scale, rotation and translation, The main advantage of this method is to speed up substantially the recognition process of the shapes, mainly because it is possible to design the classification rule in a hierarchical way. It is therefore suitable for objects to be sorted in a factory environment where the silhouette boundary supplies sufficient information for identification.Yayın Digital color halftoning(IEEE-INST Electrical Electronics Engineers Inc, 2005-01) Baqai, F. A.; Lee, J. H.; Agar, A. Ufuk; Allebach, Jan P.Digital color halftoning is done to create the perception of a continuous-tone color image using the limited spatiochromatic discrimination capability of the human visual system. Several techniques to perform this task are now available. These techniques are broadly classified into three groups: approaches that characterize the spectral distribution created by a certain combination of colorant dots at a given printer addressable location; dot model based approaches; and empirical tone correction based approaches.
