Results 241 to 250 of about 716,617 (262)
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1995
It is actually difficult to characterize directly a covariance function matrix. This becomes easy in the spectral domain on the basis of Cramer’s generalization of the Bochner theorem, which is presented in this chapter. We consider complex covariance functions.
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It is actually difficult to characterize directly a covariance function matrix. This becomes easy in the spectral domain on the basis of Cramer’s generalization of the Bochner theorem, which is presented in this chapter. We consider complex covariance functions.
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Space-Time Covariance Functions
Journal of the American Statistical Association, 2005This work considers a number of properties of space–time covariance functions and how these relate to the spatial-temporal interactions of the process. First, it examines how the smoothness away from the origin of a space–time covariance function affects, for example, temporal correlations of spatial differences.
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Lorentz-Covariant Generalized Functions
1990By Minkowski space M we mean the four-dimensional real space R 4 endowed with the pseudo-Euclidean scalar product $$ pq = {p^0}{q^0} - pq = g\lambda \mu {p^\lambda }{q^\mu } = p\lambda {q^\lambda }. $$ (3.1)
N. N. Bogolubov +4 more
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Planar geodetic covariance functions
Reviews of Geophysics, 1981In the last 20 years statistical methods have been applied in geodesy with considerable success, both in physical geodesy (least squares collocation, variance‐covariance propagation) and in geodetic measuring technique (error propagation and interpolation, inertial navigation, adjustment, diagnosis, and design of networks).
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Conformal covariant Wightman functions
Il Nuovo Cimento A, 1973In this paper a method to build covariant Wightman functions is given. Complications due to the breaking of causality are discussed. After giving a convenient definition of co-ordinate inversion to avoid the appearance of antilinear transformations, the representations of the inversion operator for various fields are given.
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Covariant Hyperelliptic Functions of Genus Two
Theoretical and Mathematical Physics, 2003zbMATH Open Web Interface contents unavailable due to conflicting licenses.
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On Covariance Functions of Unit Processes
SIAM Journal on Applied Mathematics, 1972The problem of meaningful characterization of the covariance functions, “unit covariances,” of two-valued stationary stochastic processes is considered. Some general properties are derived. For some broad classes of unit covariances, corresponding to two-valued processes with a specified structure of axis crossing, complete and explicit ...
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Examples of Covariance Functions
1995We present a few models of covariance functions. They are defined for isotropic (i.e. rotation invariant) random functions. On the graphical representations the covariance functions are plotted as variograms using the relation γ(h) = C(0) - C(h).
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A class of covariate-dependent spatiotemporal covariance functions.
The annals of applied statisticsIn geostatistics, it is common to model spatially distributed phenomena through an underlying stationary and isotropic spatial process. However, these assumptions are often untenable in practice because of the influence of local effects in the correlation structure.
Brian J, Reich +4 more
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Variogram and Covariance Function
1995The experimental variogram is a convenient tool for the analysis of spatial data as it is based on a simple measure of dissimilarity. Its theoretical counterpart reveals that a broad class of phenomena are adequately described by it, including phenomena of unbounded variation.
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