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Johnson R.W.,Alphawave Research
International Journal of Wavelets, Multiresolution and Information Processing | Year: 2012

The forward and inverse wavelet transform using the continuous Morlet basis may be symmetrized by using an appropriate normalization factor. The loss of response due to wavelet truncation is addressed through a renormalization of the wavelet based on power. The spectral density has physical units which may be related to the squared amplitude of the signal, as do its margins the mean wavelet power and the integrated instant power, giving a quantitative estimate of the power density with temporal resolution. Deconvolution with the wavelet response matrix reduces the spectral leakage and produces an enhanced wavelet spectrum providing maximum resolution of the harmonic content of a signal. Applications to data analysis are discussed. © 2012 World Scientific Publishing Company.


Johnson R.W.,Alphawave Research
European Physical Journal C | Year: 2010

Excited states are extracted from lattice correlation functions using a non-uniform prior on the model parameters. Models for both a single exponential and a sum of exponentials are considered, as well as an alternate model for the orthogonalization of the correlation functions. Results from an analysis of torelon and glueball operators indicate the Bayesian methodology compares well with the usual interpretation of effective mass tables produced by a variational procedure. Applications of the methodology are discussed. © 2010 Springer-Verlag / Società Italiana di Fisica.


Johnson R.W.,Alphawave Research
Astrophysics and Space Science | Year: 2011

To investigate the relation between observations of the 10.7 cm flux and the international sunspot number so that a physical unit may be ascribed to historical records, both polynomial and power law models are developed giving the radio flux as a function of sunspot number and vice versa. Bayesian data analysis is used to estimate the model parameters and to discriminate between the models. The effect on the parameter uncertainty and on the relative evidence of normalizing the measure of fit is investigated. The power law giving flux as a function of sunspot number is found to be the most plausible model and may be used to estimate the radio flux from historical sunspot observations. © 2010 Springer Science+Business Media B.V.


Johnson R.W.,Alphawave Research
Astrophysics and Space Science | Year: 2010

The continuous wavelet transform is adapted to account for signal truncation through renormalization and by modifying the shape of the analyzing window. Comparison is made of the instant, integrated, and mean wavelet power with previous algorithms. The edge adapted and renormalized admissible wavelet transforms are used to estimate the level of solar magnetic activity from the sunspot record. The solar activity is compared to Oerlemans' temperature reconstruction and to the Central England Temperature record. A correlation is seen for years between 1610 and 1990, followed by a strong deviation as the recently observed temperature increases. © Springer Science+Business Media B.V 2010.


Johnson R.W.,Alphawave Research
Mechanics Research Communications | Year: 2011

The neoclassical prescription to use an equation of motion to determine the electrostatic field within a tokamak plasma is fraught with difficulties. Herein we examine two popular expressions for the equilibrium electrostatic field so determined and show that one fails to withstand a formal scrutiny thereof while the other fails to respect the vector nature of the diamagnetic current. Reconsideration of the justification for the presence of the equilibrium electrostatic field indicates that no field is needed for a neutral plasma when considering the net bound current defined as the curl of the magnetization. With any shift in the toroidal magnetic flux distribution, a dynamic electric field is generated with both radial and poloidal components, providing an alternate explanation for any measurements thereof. © 2011 Elsevier Ltd. All rights reserved.


Johnson R.W.,Alphawave Research
Journal of Plasma Physics | Year: 2011

Following the arguments presented by Mansuripur [Opt. Express, vol. 16, 2008, pp. 14821-14835], we suggest a form for the macroscopic electromagnetic stress tensor appropriate for ionized media. The generalized Lorentz force includes the effects of polarization forces as well as those on the free charge and current densities. The resulting tensor is written in terms of the fields D, B, E, and H. Its expression for a fully ionized medium subject to an external electromagnetic field is discussed, as are the plasma conservation equations. An apparatus is suggested for its experimental discrimination. Copyright © Cambridge University Press 2009.


Johnson R.W.,Alphawave Research
European Physical Journal D | Year: 2010

The vector potential for the Ohmic heating coil system of a tokamak is obtained in semianalytical form. Comparison is made to the potential of a simple, finite solenoid. In the quasi-static limit, the time rate of change of the potential determines the induced electromotive force through the Maxwell- Lodge effect. Discussion of the gauge constraint is included. © EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2010.


Johnson R.W.,Alphawave Research
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2010

A heatbath algorithm is proposed for pure SU(N) lattice gauge theory based on the Manton action of the plaquette element for general gauge group N. Comparison is made to the Metropolis thermalization algorithm using both the Wilson and Manton actions. The heatbath algorithm is found to outperform the Metropolis algorithm in both execution speed and decorrelation rate. Results, mostly in D=3, for N=2 through 5 at several values for the inverse coupling are presented. Copyright © American Physical Society.


Johnson R.W.,Alphawave Research
Mechanics Research Communications | Year: 2010

The standard equilibrium equation for magnetized plasma is extended to account for the magnetic polarization force. A factor of the pressure gradient arising from the magnetic decomposition of the Hall term survives the limit of vanishing magnetization and is canceled by a contribution from the magnetic polarization force, such that the proposed equation reduces to the standard form in the free current limit. Comparison of the solutions for an axially symmetric plasma column indicates agreement with the free current limit for vanishing magnetization and variation in the field and current profiles as the degree of magnetization increases. © 2010 Elsevier B.V. All rights reserved.


The derivation of the helicon dispersion relation for a uniform plasma with stationary ions subject to a constant background magnetic field is reexamined in terms of the potential formulation of electrodynamics. Under the same conditions considered by the standard derivation, the nonlinear self-coupling between the perturbed electron flow and the potential it generates is addressed. The plane wave solution for general propagation vector is determined for all frequencies and expressed in terms of a vector phasor. The behavior of the solution as described in vacuum units depends upon the ratio of conductivity to the magnitude of the background field. Only at low conductivity and below, the cyclotron frequency can significant propagation occur as determined by the ratio of skin depth to wavelength. © 2012 American Institute of Physics.

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