Global ETD Search
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Showing 1 to 17 of 17 for “"Wigner distribution"”.
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Signal reconstruction from discrete-time Wigner distribution
Wigner distribution is considered to be one of the most powerful tools for time-frequency analysis of rumvstationary signals. Wigner distribution is a bilinear signal transformation which provides two dimensional time-frequency characterization of one dimensional signals. Although much work has …
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Quantum mechanics on phase space : geometry and motion of the Wigner distribution
We study the Wigner phase space formulation of quantum mechanics and compare it to the Hamiltonian picture of classical mechanics. In this comparison we focus on the differences in initial conditions available to each theory as well as the differences in dynamics. First we derive new necessary …
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ΘΕΩΡΙΑ ΤΟΥ ΦΑΣΙΚΟΥ ΧΩΡΟΥ ΤΗΣ ΜΗ-ΑΡΝΗΤΙΚΗΣ ΣΥΝΑΡΤΗΣΗΣ ΚΑΤΑΝΟΜΗΣ ΤΥΠΟΥ WIGNER
THE PROBLEM OF THE NON-NEGATIVE WIGNER DISTRIBUTION FUNCTION IS STUDIED. IT HASBEEN RECOGNIZED THAT THE PROBLEM IS RELATED TO SOME RECOGNIZED CORRESPODENSE RULE. THE NEW WIGNER DISTRIBUTION FUNCTION IS CONNECTED TO THE HUSIMI TRANSFORMATION AND AS IT IS PROVED TAKES CLOSED FORM, WHILE AT THE SAME …
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Analysis and filtering of time-varying signals
… representations (MTFRs) such as the Wigner distribution (WD), the Pseudo-Wigner distribution (PWD), the Short-time Fourier transform (STFT) and the optimally smoothed Wigner distribution (OSWD) used in analyzing STV signals are analyzed and compared. The OSWD is shown to perform …
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Shear Madness: Signal-Dependent and Metaplectic Time-Frequency Representations
… the short-time Fourier transform, and the Wigner distribution have proven to be powerful tools for signal analysis and processing; however, current techniques are not without their drawbacks. This thesis presents two new approaches to time-frequency analysis that attempt to overcome two of …
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Statistical time-frequency analysis
… transform, the wavelet transform, and the Wigner distribution, represent signal characteristics jointly in time and frequency and provide a versatile set of tools for the analysis and processing of nonstationary signals. Recent developments have generalized the concept of TFRs, and a fairly …
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A wave-kinetic numerical method for the propagation of optical waves
… the validity of the Liouville approximation, the Wigner distribution function ( WDF ) is conserved along the conventional ray trajectories, and, thus, by discretizing the input WDF with Gaussian beamlets, we can represent the output WDF as a sum of Gaussians, from which irradiance can be obtained …
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Iterative nonlinear beam propagation method and its application in nonlinear devices
… is based on Hamiltonian ray tracing and the Wigner distribution function. First, wave propagation simulation using Hamiltonian ray tracing is illustrated and verified with different examples. Based on this, the iterative method is presented for beam propagation in nonlinear media, which is …
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Theory of phasor-field imaging
… we introduce the two-frequency spatial Wigner distribution and derive primitives that characterize its behavior. These primitives are used to analyze occlusion-aided imaging scenarios as well as to verify intuitive results in the geometric-optics limit. Consistent with prior work, we …
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Volume holographic pupils in ray, wave, statistical optics, and Wigner space
… presented in ray, wave, statistical optics, and Wigner space. Volume holograms have both a shift variant nature and multiplex capability, which can efficiently extract specific information of multi-dimensional objects by engineering imaging kernels with shift variant point spread functions and …
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Linear and nonlinear stochastic differential equations with applications
… The equations for the ensemble average of the Wigner distribution function are defined within the framework of the smoothing approximation. Special attention is paid to the so-called long-time Markovian approximation, where the discrete nature of the quantum mechanical oscillator is explicitly …
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Topics in the Theory of Quantum Degenerate Gases
… an initial thermal equilibrium, based on the Wigner representation of the N-body density operator. We show how to generate an ensemble of random classical fields sampling the initial Wigner distribution in the number conserving Bogoliubov approximation. The fields are then evolved with the …
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Topics in the theory of quantum degenerate gases
… an initial thermal equilibrium, based on the Wigner representation of the N-body density operator. We show how to generate an ensemble of random classical fields sampling the initial Wigner distribution in the number conserving Bogoliubov approximation. The fields are then evolved with the …
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Optical Three-Dimensional Image Matching Using Holographic Information
… aforementioned drawback. This method applies the Wigner distribution to the power fringe-adjusted filtered correlation output to extract the 3-D location of a matched object. We analyze the proposed method and present computer simulation and optical experiment results.
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Design and manufacturing of all-dielectric optical metamaterial with gradient index of refraction
… explaining the bi-foci was also included using Wigner distribution function and Hamiltonian ray-tracings.
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Investigation of new feature descriptors for image search and classification
… Color GLH (FC-GLH) descriptor. Finally, the Wigner based Local Binary Patterns (WLBP) descriptor is proposed that combines multi-neighborhood LBP, Pseudo-Wigner distribution of images and the popular bag of words model to effectively classify scene images. To assess the feasibility of the …
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Quasiklassischer Ansatz für volldifferentielle Ionisationsquerschnitte
Zur Bestimmung niedrig-differentieller Ionisationsquerschnitte, <br>speziell an atomarem Wasserstoff, hat sich die Methode der CTMC <br>(classical trajectory Monte-Carlo) als '`robustes Arbeitspferd'' <br>erwiesen. Diese Methode besitzt jedoch an zwei wesentlichen <br>Stellen Einschränkungen: zum …