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Browsing by Subject "Signal processing"
Now showing items 1-18 of 18
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(Optical Society of America, 2008-02-01)A signal may have compact support, be band-limited (i.e., its Fourier transform has compact support), or neither (“unbounded”). We determine conditions for the linear canonical transform of a signal having these properties. ...
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(Optical Society of America, 2010-04-15)Sampling a function periodically replicates its spectrum. As a bilinear function of the signal, the associated Wigner distribution function contains cross terms between the replicas. Often neglected, these cross terms ...
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(The Institution of Engineering and Technology, 2009-06)A system for soft error detection and correction is proposed for digital Integrated Circuit (IC) implementation of convolution. The convolution is implemented in a Residue NumberSystem using Fermat Number Theoretic Transforms. ...
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(Optical Society of America, 2007-07-01)In the usual model of an imaging system, only the effects of the aperture stop are considered in determining diffraction-limited system performance. In fact, diffraction at other stops—those associated with different lens ...
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(Optical Society of America, 2006-12-01)In speckle-based metrology systems, a finite range of possible motion or deformation can be measured. When coherent imaging systems with a single limiting aperture are used in speckle metrology, the observed decorrelation effects ...
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(IEEE, 2012-06)This paper presents a novel reference-free ultrasonic indoor location system. Unlike most previous proposals, the mobile device (MD) determines its own position based only on ultrasonic signals received at a compact sensor ...
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(IEEE, 2007-11)An important pre-processing stage in speech recognition systems is that of extracting phonetically pertinent acoustic features from the speech signal. These features form the basis for discriminative classification and ...
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(Optical Society of America, 2003-02-15)A number of methods have recently been proposed in the literature for the encryption of two-dimensional information by use of optical systems based on the fractional Fourier transform. Typically, these methods require ...
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(Optical Society of America, 2011-07-10)Modeling the propagation of light through free space and simple paraxial systems continue to be enduring, and practically important topics in optics. Is there anything new or interesting that remains to be said? Given the ...
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(Optical Society of America, 2006-11-01)Digital speckle photography can be used in the analysis of surface motion in combination with an optical linear canonical transform (LCT). Previously [D. P. Kelly et al. Appl. Opt. 44, 2720 (2005)] it has been shown that ...
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(Optical Society of America, 2010-04-01)The linear canonical transform may be used to simulate the effect of paraxial optical systems on wave fields. Using a recent definition of the discrete linear canonical transform, phase space diagram analyses of the ...
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(Optical Society of America, 2010-06-07)A concise review is presented of research recently carried out within our research group. Topics discussed include: (i) Imaging through turbulent media using Lucky Imaging combined with synthetic apertures; (ii) ...
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(IEEE, 2011-10)This paper presents a novel method for ultrasonic range estimation. The method uses a wideband frequency-hop spread spectrum ultrasonic signal to increase robustness to noise and reverberation. The method applies ...
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(Optical Society of America, 2007-05-01)A novel technique for multiplexing complex images is proposed in which each image may be demultiplexed only if a set of random encryption keys is known. The technique utilizes the ability of the double random phase encoding ...
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(Optical Society of America, 2004-03-01)The relationship between optical fractional Fourier transforms (OFRTs) obtained at different wavelengths is derived by use of the ABCD matrix formalism. It is shown that varying the wavelength while retaining the same ...
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(Institution of Civil Engineers/Thomas Telford Publishing, 2012-03-01)Accurate determination of shear wave arrival time using bender elements may be severely affected by a combination of near field effects and reflected waves. These may mask the first arrival of the shear wave, making its ...
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(Elsevier, 2006-11)Bridge Weigh-In-Motion (B-WIM) is a process by which the axle and gross vehicle weights of vehicles travelling at highway speeds can be determined from instrumented bridges. The traditional method of attaching strain ...
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(Optical Society of America, 2009-10-11)If we sample a scalar wave field, it becomes periodic in frequency. We examine the cross-terms which occur between these periodic replicas in the Wigner-Ville distribution function of such a signal. We present analytic ...
Now showing items 1-18 of 18