We consider the problem of embedding point cloud data sampled from an underlying manifold with an associated flow or velocity. Such data arises in many contexts where static snapshots of dynamic entities are measured,...
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The key issues in CO2 sequestration monitoring involve accurate monitoring, from the injection stage to prediction & verification, of CO2 movement over time for environmental considerations. A natural non-intrusiv...
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In this paper we consider a parameter estimation problem for delay differential equations that are typical in the bioscience. The problem is motivated by a model of the dynamics of the intracellular development cycle ...
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The work of O'Malley et al. (1961) and of Levy et al. (1963) is extended to obtain higher-order terms in the energy dependence of elastic-scattering phase shifts that arise from long-range inverse power forces. Th...
The work of O'Malley et al. (1961) and of Levy et al. (1963) is extended to obtain higher-order terms in the energy dependence of elastic-scattering phase shifts that arise from long-range inverse power forces. The expressions, in terms of the coefficients of the long-range inverse power potentials, give useful predictions of higher partial-wave phaseshifts. A further application would be in work on the determination of phaseshifts from scattering data.
3D structure recovery from a collection of 2D images requires the estimation of the camera locations and orientations, i.e. the camera motion. For large, irregular collections of images, existing methods for the locat...
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In this paper, we develop a general formulation of the continuous sensitivity equations for the standard k - e model of turbulence with wall functions. This formulation accounts for complex parameter dependencies and ...
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Characterization and implementation of efficient rotational motions of flexible spacecraft have been of research interest for more than twenty years. In the present study we consider rest-to-rest pointing maneuvers fo...
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ISBN:
(纸本)1563478080
Characterization and implementation of efficient rotational motions of flexible spacecraft have been of research interest for more than twenty years. In the present study we consider rest-to-rest pointing maneuvers for a very large spacecraft, so that limits on available angular momentum are paramount. A formal system of differential equations is developed based on a model that includes a rigid central hub and Euler-Bernoulli appendages. The model is recast in an appropriate state-space and standard functional analysis methods are used to prove well-posedness and to establish a framework for numerical approximation. Several variants of minimum-angular moment problems are studied;ultimately we focus on a low-dimensional control parameterization based on a family of versine functions and on quasi-static structural response. Results are characterized in terms of simple formulae and sensitivity with respect to problem data is presented.
In earlier papers, 2π-periodic spectral data windows have been used in spectral estimation of discrete-time random fields having finite second-order moments. In this paper, we show that 2π-periodic spectral windows ...
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In earlier papers, 2π-periodic spectral data windows have been used in spectral estimation of discrete-time random fields having finite second-order moments. In this paper, we show that 2π-periodic spectral windows can also be used to construct estimates of the spectral density of a homoge-neous symmetric α-stable discrete-time random field. These fields do not have second-order moments if 0 < α < 2. We construct an estimate of the spectrum, calculate the asymptotic mean and variance, and prove weak consistency of our estimate.
Using recently developed methods in nonlinear dynamics, two hypotheses often advanced to account for recurrent outbreaks of childhood diseases such as measles are investigated. The first, maintenance of otherwise damp...
Using recently developed methods in nonlinear dynamics, two hypotheses often advanced to account for recurrent outbreaks of childhood diseases such as measles are investigated. The first, maintenance of otherwise damped oscillations by noise, appears incapable of reproducing essential features of the data. The second, cycles and chaos sustained by seasonal variation in contact rates gives qualitative and quantitative agreement between model and observation. It is concluded that nonlinear dynamics offers a methodology which may allow students of ecology and epidemiology to distinguish between competing mechanistic hypotheses.
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