Browsing by Keywords "Sampling"
Now showing items 1-19 of 19
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Accounting for parameter uncertainty in large-scale stochastic simulations with correlated inputs
(Institute for Operations Research and the Management Sciences (I N F O R M S), 2011)This paper considers large-scale stochastic simulations with correlated inputs having normal-to-anything (NORTA) distributions with arbitrary continuous marginal distributions. Examples of correlated inputs include processing ... -
Application of signal-processing techniques to reduce the errors related to the FDTD excitations
(IEEE, 2001)A study on the reduction of the errors related to the finite-difference time-domain (FDTD) excitations was performed by employing signal-processing techniques. Plane-wave scattering problems were simulated. The improvements ... -
A aurvey of signal processing problems and tools in holographic three-dimensional television
(Institute of Electrical and Electronics Engineers, 2007)Diffraction and holography are fertile areas for application of signal theory and processing. Recent work on 3DTV displays has posed particularly challenging signal processing problems. Various procedures to compute ... -
Automatic detection of compound structures by joint selection of region groups from a hierarchical segmentation
(Institute of Electrical and Electronics Engineers, 2016)A challenging problem in remote sensing image analysis is the detection of heterogeneous compound structures such as different types of residential, industrial, and agricultural areas that are composed of spatial arrangements ... -
DCT coding of nonrectangularly sampled images
(IEEE, 1994)Discrete cosine transform (DCT) coding is widely used for compression of rectangularly sampled images. In this letter, we address efficient DCT coding of nonrectangularly sampled images. To this effect, we discuss an ... -
Diffraction and holography from a signal processing perspective
(SPIE, 2006)The fact that plane waves are solutions of the Helmholtz equation in free space allows us to write the exact solution to the diffraction problem as a superposition of plane waves. The solution of other related problems can ... -
The effect of distribution of information on recovery of propagating signals
(Bilkent University, 2015-09)Interpolation is one of the fundamental concepts in signal processing. The analysis of the di fficulty of interpolation of propagating waves is the subject of this thesis. It is known that the information contained in a ... -
An efficient and accurate technique for the incident-wave excitations in the FDTD method
(Institute of Electrical and Electronics Engineers, 1998-06)An efficient technique to improve the accuracy of the finite-difference time-domain (FDTD) solutions employing incident-wave excitations is developed. In the separate-field formulation of the FDTD method, any incident wave ... -
Efficient computation of the ambiguity function and the Wigner distribution on arbitrary line segments
(IEEE, Piscataway, NJ, United States, 1999)Efficient algorithms are proposed for the computation of Wigner distribution and ambiguity function samples on arbitrary line segments based on the relationship of Wigner distribution and ambiguity function with the ... -
Finite representation of finite energy signals
(Bilkent University, 2011)In this thesis, we study how to encode finite energy signals by finitely many bits. Since such an encoding is bound to be lossy, there is an inevitable reconstruction error in the recovery of the original signal. We also ... -
Interpolating between periodicity and discreteness through the fractional Fourier transform
(IEEE, 2006)Periodicity and discreteness are Fourier duals in the same sense as operators such as coordinate multiplication and differentiation, and translation and phase shift. The fractional Fourier transform allows interpolation ... -
A multiresolution nonrectangular wavelet representation for two-dimensional signals
(Elsevier, 1993)In this paper, a new multiresolution wavelet representation for two-dimensional signals is described. This wavelet representation is based on a nonrectangular decomposition of the frequency domain. The decomposition can ... -
Optimal representation and processing of optical signals in quadratic-phase systems
(Elsevier, 2016)Optical fields propagating through quadratic-phase systems (QPSs) can be modeled as magnified fractional Fourier transforms (FRTs) of the input field, provided we observe them on suitably defined spherical reference surfaces. ... -
Reducing the dispersion errors of the finite-difference time-domain method for multifrequency plane-wave excitations
(Taylor & Francis, 2003)We demonstrate the applications of discrete-time signal-processing (SP) techniques for the purpose of generating accurate plane waves in the finite-difference time-domain (FDTD) method. The SP techniques are used either ... -
Sampling and series expansion theorems for fractional Fourier and other transforms
(Elsevier, 2003)The sampling and series expansion theorems for fractional Fourier transforms were analyzed. In addition to the fractional Fourier transform, the method can also be applied to the Fresnel, Hartley and scale transforms. The ... -
Signal processing issues in diffraction and holographic 3DTV
(Elsevier BV, 2007)Image capture and image display will most likely be decoupled in future 3DTV systems. Due to the need to convert abstract representations of 3D images to display driver signals, and to explicitly consider optical diffraction ... -
Signal-processing techniques to reduce the sinusoidal steady-state error in the FDTD method
(IEEE, 2000-04)Techniques to improve the accuracy of the finite-difference time-domain (FDTD) solutions employing sinusoidal excitations are developed. The FDTD computational domain is considered as a sampled system and analyzed with ... -
Some mathematical properties of the uniformly sampled quadratic phase function and associated issues in digital Fresnel diffraction simulations
(SPIE - International Society for Optical Engineering, 2004)The quadratic phase function is fundamental in describing and computing wave-propagation-related phenomena under the Fresnel approximation; it is also frequently used in many signal processing algorithms. This function has ... -
Synthetic TEC mapping with ordinary and universal kriging
(IEEE, 2007-06)Spatiotemporal variations in the ionosphere affects the HF and satellite communications and navigation systems. Total Electron Content (TEC) is an important parameter since it can be used to analyze the spatial and temporal ...
