Yazar "Ucar, FN" seçeneğine göre listele

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  • Küçük Resim
    Öğe
    Beam space processing for low-cost scanners
    (I E E E, 1996) Ucar, FN; Karaman, M
    A subaperture processing technique suitable for low-cost ultrasound imaging systems is presented. The technique is based on multi-element synthetic aperture approach and beam interpolation. A large receive aperture is synthesized using a transmit subaperture at the transducer array center and a number of non-overlapping receive subapertures multiplexed across the array. The number of beam lines scanning a sector angle is chosen according to the spatial Nyquist criteria of a single transmit-receive subaperture. The beam count is increased through digital interpolation, where a linear filter with a different spatial frequency band for each subaperture is employed. This technique reduces the number of firings in data acquisition and hence permits real-time synthetic aperture processing with low susceptibility to motion artifacts.
  • Küçük Resim
    Öğe
    A noise reduction algorithm in ECG signals using wavelet transform
    (Ieee, 1998) Ucar, FN; Korurek, M; Yazgan, E
    A noise reduction algorithm based on multiresolution orthogonal wavelet transform in ECG signals is discussed. The results are presented for different analysis and synthesis filter coefficients proposed by Vetterli-Herley and Daubechies for two different noise characteristics. The first one is artificially obtained line interference sinusoidal noise and the second one is uniformly distributed random noise or white noise. The results show that the former noise is completely eliminated from the signal by using both of the filter coefficients. However, the latter noise did not give the same performance as that of the former one.