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Showing 1 to 20 of 925 for “"Dispersive"”.
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Improving the Dispersive Optical Model toward a Dispersive Self-energy Method
The connection between the dispersive optical potential and the irreducible nucleon self-energy from Green's function theory is improved, providing a tighter link between nuclear reactions and nuclear structure. In particular, since the self-energy is inherently nonlocal, an explicitly nonlocal …
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Resonance in dispersive wave systems
… three wave equations containing higher order dispersive terms was investigated with the intention of providing a link between the continuous and discrete three wave cases. Both analytic and numerical studies were conducted for a number of parameter regimes. In particular for the case analogous …
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Dispersive Estimates for the Schrodinger Equation
Finally in Chapter 3 we consider a problem involving the non-linear Schrodinger equation. In particular, we consider the following equation that arises in fiber optic communication systems, iut+dtu xx+u2u=0. We can reduce this to a non-linear, non-local eigenvalue equation that describes the …
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Dispersive estimates for the Schrödinger equation
Item withdrawn by Mark Zulauf (zulauf@illinois.edu) on 2010-06-30T12:54:50Z Item was in collections: University of Illinois Theses & Dissertations (ID: 1) No. of bitstreams: 1 Green_William.pdf: 999536 bytes, checksum: 87eb33f24c92fd62a4874b5db34bf8da (MD5)
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Dispersive waves in Earth's outer core
… field lines, are united by the fact they are dispersive - which is to say, the velocity at which a given wave travels is a function of the spacing and orientation of its wave crests; the behaviour of such waves is remarkably rich and has frequently counter-intuitive consequences. Our analysis …
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Computational studies of nonlinear dispersive plasma systems
<p>Plasma systems with dispersive waves are ubiquitous. Dispersive waves have the property that their wave velocity depends on the wave number of the wave. These waves show up in weakly as well as strongly coupled plasmas, and play a significant role in the underlying plasma dynamics. Dispersive …
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Dispersive neural networks for adaptive signal processing
… thesis extends the back-propagation technique to dispersive networks, which contain internal delay elements. Both the delays and the weights adapt to minimize the error at the output. Dispersive networks can perform many tasks, including signal prediction, signal production, channel equalization, …
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Dispersive phonon imaging in III-V semiconductors
… background due to scattered phonons. In the dispersive regime, where phonon wavelength is comparable to atomic spacing, the angular positions of these caustic lines are very sensitive to phonon frequency, thus providing a novel test for lattice dynamics theories. Experiments are performed …
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Nonlinear dispersive equations with random initial data
In the first part of this thesis we consider the defocusing nonlinear wave equation of power-type on R3. We establish an almost sure global existence result with respect to a suitable randomization of the initial data. In particular, this provides examples of initial data of supercritical …
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Dispersive Characteristics of Left Ventricle Filling Waves
… LV filling waves in a normal ventricle act as dispersive waves and not only propagate along the length of the LV but also spread and disperse in the direction of the apex. In certain diseased ventricles, this dispersion is limited due to changes in LV geometry and wall motion. This improved …
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Stability of Periodic Waves in Nonlocal Dispersive Equations
In this work consisting of joint projects with my advisor, Dr. Mathew Johnson, we study the existence and stability of periodic waves in equations that possess nonlocal dispersion, i.e. equations in which the dispersion relation between the temporal frequency, omega, and wavenumber, k, of a plane …
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The interaction of shock waves and dispersive waves
… which model the interaction of shocks with a dispersive wave envelope. The system mimics the Zakharov equations from weak plasma turbulence theory but replaces the linear wave equation in that system by a nonlinear equation allowing shock formation. This nonlinear equation is a hyperbolic …
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Three-dimensional solitary waves in dispersive wave systems
… attention than two-dimensional solitary waves in dispersive wave systems. Prior studies have focused in the long-wave limit, where lumps exist if the long-wave speed is a minimum of the phase speed and are described by the Kadomtsev-Petviashvili (KP) equation. In the water-wave problem, in …
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Dispersive mixing in a partially saturated porous medium.
Massachusetts Institute of Technology. Dept. of Civil Engineering. Thesis. 1974. Ph.D.
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Propagation of electromagnetic waves in spatially dispersive inhomogeneous media
… behaviour of electromagnetic waves in spatially dispersive, inhomogeneous media. In particular, two types of inhomogeneity are considered: media formed from two homogeneous regions with a common interface, and those with a periodic structure. For a material made of two homogeneous regions joined …
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Stability bounds for nonlinear dispersive Hamiltonian partial differential equations
Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2024-03-01 without embargo terms
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Smoothing properties of certain dispersive nonlinear partial differential equations
… concerned with the smoothing properties of dispersive equations and systems. Smoothing in this context means that the nonlinear part of the solution flow is of higher regularity than the initial data. We establish this property, and some of its consequences, for several equations. The first …
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The role of smoothing effect in some dispersive equations
… effect in the local well-posedness theory of dispersive partial differential equations in three different contexts. First, we use it to overcome a loss of derivatives in a family of nonlocal dispersive equations. Second, we exploit a discrete version of the smoothing effect to study a discrete …
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Dispersive Transport and Drift Mobilities in Methylammonium Lead Iodide Perovskites
… methylammonium lead iodide. I found evidence of dispersive transport for both photocharge carriers. I have made transient temperature-dependent studies of the drift mobility and the dispersion parameter, under otherwise normal device operating conditions. The low values of the electron and hole …
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