Results 271 to 280 of about 86,067 (310)
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Theory of Time-Averaged-Product Arrays
The Journal of the Acoustical Society of America, 1957The mathematical analysis of the directional characteristics of linear additive arrays is given in a polynomial representation. The result of multiplying and taking a time average of the outputs of several detectors also has directional characteristics that may be expressed as polynomials.
A. Berman, C. S. Clay
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Averaging theory for functional differential equations
Proceedings of the 37th IEEE Conference on Decision and Control (Cat. No.98CH36171), 2002Previous work by the authors (1997, 1998) has established new averaged models for time-dependent functional differential equations (FDE). In this paper,we present new theorems extending the existing theory to infinite time intervals and a more general class of FDE. Improvements over the classical theory are illustrated in simulations.
B. Lehman, S.P. Weibel
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Kolmogorov theory via finite-time averages
Physica D: Nonlinear Phenomena, 2005zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Foias, C. +4 more
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Fermion-field theory and configuration averaging
Journal of Physics C: Solid State Physics, 1975The configuration-averaging theory of Mookerjee (see abst. A38777, a43969 of 1973) using a disorder field is put here in an equivalent picture of an electron interacting with a fermion field. This provides a more physical background to the mathematically abstruse formalism and also provides a justification to the CPA and cluster cpas proposed by Bishop
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On the convergence of Z-averaged perturbation theory
The Journal of Chemical Physics, 2008Very high order open-shell Z-averaged perturbation theory (ZAPT) energies, equilibrium bond lengths, and harmonic vibrational frequencies have been computed for a suite of small molecules using a determinantal algorithm. The convergence of ZAPTn energies is compared to alternative Møller–Plesset (MP) perturbation theories built on restricted open-shell
Steven E, Wheeler +2 more
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1976
The purpose of this paper is to present a number of recently obtained results in averaging, both in theory and in applications, and to show at the same time what kind of pitfalls there are in applying the theory to problems in dynamics.
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The purpose of this paper is to present a number of recently obtained results in averaging, both in theory and in applications, and to show at the same time what kind of pitfalls there are in applying the theory to problems in dynamics.
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Resonances in Multifrequency Averaging Theory
1994The Whitham method allows to obtain rapidly oscillating asymptotic solutions of nonlinear equations with a small parameter e which characterizes the dispersion. The principal term of such asymptotic solutions can be represented in the form $$ u = f\left( {\frac{{S\left( {x,t} \right)}}{\varepsilon },x,t} \right)$$ (1.1) , where f (τ, x, t ...
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Analyticity, Uniform Averaging and K-Theory
1994Let (A, R, α) be a C*-dynamical systerr, let H∞(α) be the subalgebra of A consisting of those a in A such that the Arveson spectrum of a is contained in [0, ∞), and let Aα be the fixed point subalgebra of A. In this note we investigate conditions for the existence of an R-invariant conditional expectation from A onto Aα and we show that when such an ...
Paul S. Muhly, Chaoxin Qiu, Jingbo Xia
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Elements of Thermodynamically Constrained Averaging Theory
2014Mechanistic computational modeling of environmental systems presupposes the existence of a properly posed set of equations that adequately describes the underlying physical, chemical, and biological processes at time and length scales consistent with the problem being addressed.
William G. Gray, Cass T. Miller
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Fourier interpretation of multiphase averaging theory
Advances in Water Resources, 1984Abstract There has been considerable interest over the last two decades in developing averaging methods to change the scales of motion in multiphase transport theory. More recently, these averaging methods have been related to instrumentation windows. In this article we relate the averaging theory to impulse-response filters.
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