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Related papers: Utilizing wind in spatial covariance

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We introduce a novel class of non-stationary covariance functions for random fields on linear networks that allows both the variance and the correlation range of the random field to vary spatially. The proposed covariance functions are…

Statistics Theory · Mathematics 2026-02-23 Alfredo Alegría

Spatial models for areal data are often constructed such that all pairs of adjacent regions are assumed to have near-identical spatial autocorrelation. In practice, data can exhibit dependence structures more complicated than can be…

Methodology · Statistics 2024-07-04 Michael F. Christensen , Peter D. Hoff

Wind power forecasting has drawn increasing attention among researchers as the consumption of renewable energy grows. In this paper, we develop a deep learning approach based on encoder-decoder structure. Our model forecasts wind power…

Machine Learning · Computer Science 2021-10-08 Jiangyuan Li , Mohammadreza Armandpour

We present a 3D dynamical model of the orbital induced curvature of the wind-wind collision region in binary star systems. Momentum balance equations are used to determine the position and shape of the contact discontinuity between the…

Astrophysics · Physics 2009-11-13 E. R. Parkin , J. M. Pittard

We summarize properties of the spatial sign covariance matrix and especially look at the relationship between its eigenvalues and those of the shape matrix of an elliptical distribution. The explicit relationship known in the bivariate case…

Methodology · Statistics 2016-06-08 Alexander Dürre , Roland Fried , Daniel Vogel

In 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…

Applications · Statistics 2012-02-29 Brian J. Reich , Jo Eidsvik , Michele Guindani , Amy J. Nail , Alexandra M. Schmidt

Multivariate spatial-statistical models are often used when modeling environmental and socio-demographic processes. The most commonly used models for multivariate spatial covariances assume both stationarity and symmetry for the…

Methodology · Statistics 2021-05-11 Quan Vu , Andrew Zammit-Mangion , Noel Cressie

We study the two-point correlation function of density perturbations in a spherically symmetric void universe model which does not employ the Copernican principle. First we solve perturbation equations in the inhomogeneous universe model…

Cosmology and Nongalactic Astrophysics · Physics 2013-12-25 Ryusuke Nishikawa , Chul-Moon Yoo , Ken-ichi Nakao

There exist several theoretical motivations for primordial correlation functions (such as the power spectrum) to contain oscillations as a logarithmic function of comoving momentum k. While these features are commonly searched for in…

High Energy Physics - Theory · Physics 2014-01-22 Mark G. Jackson , Ben Wandelt , François Bouchet

The prevalence of spatially referenced multivariate data has impelled researchers to develop a procedure for the joint modeling of multiple spatial processes. This ordinarily involves modeling marginal and cross-process dependence for any…

Methodology · Statistics 2020-07-10 Ghulam A. Qadir , Ying Sun

The anisotropy of turbulence in the fast solar wind, between the ion and electron gyroscales, is directly observed using a multispacecraft analysis technique. Second order structure functions are calculated at different angles to the local…

Spatial data display correlation between observations collected at neighboring locations. Generally, machine and deep learning methods either do not account for this correlation or do so indirectly through correlated features and thereby…

Methodology · Statistics 2024-10-08 Matthew J. Heaton , Andrew Millane , Jake S. Rhodes

The small and large scale problem of various passive vector models with anisotropic forcing is considered by solving exactly the equation for the pair correlation function. Emphasis is placed in the phenomena of anomalous scaling and the…

Chaotic Dynamics · Physics 2013-05-29 Heikki Arponen

Polytropic models of stellar winds remain to be useful tools because they allow for a simple description of the energy balance of the expanding plasma without explicitly specifying potentially complex energy transport processes like, e.g.,…

Solar and Stellar Astrophysics · Physics 2026-04-23 L. Westrich , B. Shergelashvili , H. Fichtner , V. N. Melnik

Diffusion tensor coefficients play a central role in describing cosmic-ray transport in various astrophysical environments permeated with magnetic fields, which are usually modeled as a fluctuating field on top of a mean field. In this…

High Energy Astrophysical Phenomena · Physics 2024-07-09 O. Deligny

If one is willing to give up the cherished hypothesis of spatial isotropy, many interesting cosmological models can be developed beyond the simple anisotropically expanding scenarios. One interesting possibility is presented by shear-free…

Cosmology and Nongalactic Astrophysics · Physics 2015-07-22 Thiago S. Pereira , Guillermo A. Mena Marugán , Saulo Carneiro

The construction of valid and flexible cross-covariance functions is a fundamental task for modeling multivariate space-time data arising from climatological and oceanographical phenomena. Indeed, a suitable specification of the covariance…

Statistics Theory · Mathematics 2017-11-23 Alfredo Alegría , Emilio Porcu , Reinhard Furrer , Jorge Mateu

The analysis of space-time data from complex, real-life phenomena requires the use of flexible and physically motivated covariance functions. In most cases, it is not possible to explicitly solve the equations of motion for the fields or…

Methodology · Statistics 2016-06-29 Dionissios T. Hristopulos , Ivi C. Tsantili

Forecasting a particular variable can depend upon temporal or spatial scale. Temporal variations that indicate variations with time, reflect the stochasticity present in the variable. Spatial variation usually are dominant in climatology…

Signal Processing · Electrical Eng. & Systems 2020-09-07 Harsh S. Dhiman , Dipankar Deb

Generalizing recent work on isotropic tensor fields in isotropic and achiral condensed matter systems from two to arbitrary dimensions we address both mathematical aspects assuming perfectly isotropic systems and applications focusing on…

Soft Condensed Matter · Physics 2024-10-22 J. P. Wittmer