Browsing by Keywords "Eigenvalues and eigenfunctions"
Now showing items 120 of 44

Analysis of crosscorrelations between financial markets after the 2008 crisis
(Elsevier BV, 2013)We analyze the crosscorrelation matrix C of the index returns of the main financial markets after the 2008 crisis using methods of random matrix theory. We test the eigenvalues of C for universal properties of random ... 
Canonicalcovariant Wigner function in polar form
(OSA  The Optical Society, 2000)The twodimensional Wigner function was investigated in polar canonical coordinates. The covariance properties under the action of affine canonical transformations were derived. The polar canonical phasespace representations ... 
Characteristic equations for the lasing Modes of infinite periodic chain of quantum wires
(2008)In this paper, we study the lasing modes of a periodic open optical resonator. The resonator is an infinite chain of active circular cylindrical quantum wires standing in tree space. Characteristic equations for the ... 
Classification of closed and open shell pistachio nuts using principal component analysis of impact acoustics
(2004)An algorithm was developed to separate pistachio nuts with closedshells from those with openshells. It was observed that upon impact on a steel plate, nuts with closedshells emit different sounds than nuts with openshells. ... 
Componentwise bounds for nearly completely decomposable Markov chains using stochastic comparison and reordering
(Elsevier, 2005)This paper presents an improved version of a componentwise bounding algorithm for the state probability vector of nearly completely decomposable Markov chains, and on an application it provides the first numerical results ... 
Continuous and discrete fractional fourier domain decomposition
(IEEE (Institute of Electrical and Electronics Engineers), 2000)We introduce the fractional Fourier domain decomposition for continuous and discrete signals and systems. A procedure called pruning, analogous to truncation of the singularvalue decomposition, underlies a number of ... 
Counting surrounding nodes using DSSS signals and de Bruijn sequences in blind environment
(2013)In recent years the technological development has encouraged several applications based on node to node communications without any fixed infrastructure. This paper presents preliminary evaluation of popular estimating ... 
Coupled optical microcavities in onedimensional photonic bandgap structures
(Institute of Physics Publishing, 2001)We present a detailed theoretical and experimental study of the evanescent coupled optical microcavity modes in onedimensional photonic bandgap structures. The coupledcavity samples are fabricated by depositing alternating ... 
Digital computation of the fractional Fourier transform
(Institute of Electrical and Electronics Engineers, 199609)An algorithm for efficient and accurate computation of the fractional Fourier transform is given. For signals with timebandwidth product N, the presented algorithm computes the fractional transform in O(NlogN) time. A ... 
Disorder and localization in the lowest Landau level in the presence of dilute point scatterers
(Pergamon Press, 1999)We study the localization properties of a twodimensional noninteracting electron gas in the presence of randomly distributed shortrange scatterers in very high magnetic fields. We evaluate the participation number of the ... 
An empirical eigenvaluethreshold test for sparsity level estimation from compressed measurements
(European Signal Processing Conference, EUSIPCO, 2014)Compressed sensing allows for a significant reduction of the number of measurements when the signal of interest is of a sparse nature. Most computationally efficient algorithms for signal recovery rely on some knowledge ... 
Equivalence of linear canonical transform domains to fractional Fourier domains and the bicanonical width product: a generalization of the spacebandwidth product
(Optical Society of America, 20100730)Linear canonical transforms (LCTs) form a threeparameter family of integral transforms with wide application in optics. We show that LCT domains correspond to scaled fractional Fourier domains and thus to scaled oblique ... 
Exact diffraction calculation from fields specified over arbitrary curved surfaces
(Elsevier, 20110730)Calculation of the scalar diffraction field over the entire space from a given field over a surface is an important problem in computer generated holography. A straightforward approach to compute the diffraction field from ... 
Fast and accurate algorithm for the computation of complex linear canonical transforms
(Optical Society of America, 20100805)A fast and accurate algorithm is developed for the numerical computation of the family of complex linear canonical transforms (CLCTs), which represent the inputoutput relationship of complex quadraticphase systems. ... 
Fast and accurate linear canonical transform algorithms
(Institute of Electrical and Electronics Engineers Inc., 2015)Linear canonical transforms are encountered in many areas of science and engineering. Important transformations such as the fractional Fourier transform and the ordinary Fourier transform are special cases of this transform ... 
The fractional Fourier domain decomposition
(Elsevier, 1999)We introduce the fractional Fourier domain decomposition. A procedure called pruning, analogous to truncation of the singularvalue decomposition, underlies a number of potential applications, among which we discuss fast ... 
The Fractional Fourier transform and harmonic oscillation
(Springer, 2002)The athorder fractional Fourier transform is a generalization of the ordinary Fourier transform such that the zerothorder fractional Fourier transform operation is equal to the identity operation and the firstorder ... 
The fractional fourier transform and its applications to image representation and beamforming
(2003)The ath order fractional Fourier transform operator is the ath power of the ordinary Fourier transform operator. We provide a brief introduction to the fractional Fourier transform, discuss some of its more important ... 
A general theory on spectral properties of statehomogeneous finitestate quasibirthdeath processes
(Elsevier, 2001)In this paper a spectral theory pertaining to QuasiBirth–Death Processes (QBDs) is presented. The QBD, which is a generalization of the birth–death process, is a powerful tool that can be utilized in modeling many stochastic ... 
Highly directional enhanced radiation from sources embedded inside two and threedimensional photonic crystals
(2005)In this work, we have experimentally and theoretically studied the emission of radiation from a monopole source embedded in a two and three dimensional photonic crystal. We have demonstrated the enhancement of radiation ...