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Standard geostatistical models assume stationarity and rely on a variogram model to account for the spatial dependence in the observed data. In some instances, this assumption that the spatial dependence structure is constant throughout the…

Methodology · Statistics 2022-12-16 Dave Higdon , Jenise Swall , John Kern

We present a stochastic model of gait rhythm dynamics, based on transitions between different ``neural centers'', that reproduces distinctive statistical properties of normal human walking. By tuning one model parameter, the hopping range,…

Statistical Mechanics · Physics 2009-11-07 Yosef Ashkenazy , Jeffrey M. Hausdorff , Plamen Ch. Ivanov , Ary L. Goldberger , H. Eugene Stanley

Spatial systems with heterogeneities are ubiquitous in nature, from precipitation, temperature and soil gradients controlling vegetation growth to morphogen gradients controlling gene expression in embryos. Such systems, generally described…

Dynamical Systems · Mathematics 2023-05-10 Denis D. Patterson , Simon A. Levin , A. Carla Staver , Jonathan D. Touboul

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

Animal movement exhibits complex behavior which can be influenced by unobserved environmental conditions. We propose a model which allows for a spatially-varying movement rate and spatially-varying drift through a semiparametric potential…

Applications · Statistics 2017-02-28 James C. Russell , Ephraim M. Hanks , Murali Haran , David P. Hughes

This paper investigates the modeling of an important class of degradation data, which are collected from a spatial domain over time; for example, the surface quality degradation. Like many existing time-dependent stochastic degradation…

Methodology · Statistics 2017-12-29 Xiao Liu , Kyongmin Yeo , Jayant Kalagnanam

Demographic heterogeneity is often studied through the geographical lens. Therefore it is considered at a predetermined spatial resolution, which is a suitable choice to understand scalefull phenomena. Spatial autocorrelation indices are…

Physics and Society · Physics 2024-04-01 Aleksejus Kononovicius , Justas Kvedaravicius

Ambit stochastics is the name for the theory and applications of ambit fields and ambit processes and constitutes a new research area in stochastics for tempo-spatial phenomena. This paper gives an overview of the main findings in ambit…

Probability · Mathematics 2012-10-05 Ole E. Barndorff-Nielsen , Fred Espen Benth , Almut E. D. Veraart

Stochastic geometric mechanics (SGM) is known for its potential utility in quantifying uncertainty in global climate modelling of the Earth's ocean and atmosphere while also preserving the fundamental advective transport properties of ideal…

Fluid Dynamics · Physics 2023-08-30 Darryl D. Holm , Erwin Luesink

Motivated by previous work on kinetic energy cascades in the ocean and atmosphere, we develop a spatio-temporal spectral transfer tool that can be used to study scales of variability in generalized dynamical systems. In particular, we use…

This paper proposes a physical-statistical modeling approach for spatio-temporal data arising from a class of stochastic convection-diffusion processes. Such processes are widely found in scientific and engineering applications where…

Applications · Statistics 2020-08-07 Xiao Liu , Kyongmin Yeo , Siyuan Lu

Stochastic differential equations (SDEs) are established tools to model physical phenomena whose dynamics are affected by random noise. By estimating parameters of an SDE intrinsic randomness of a system around its drift can be identified…

Computation · Statistics 2012-05-03 Umberto Picchini , Susanne Ditlevsen

Stochastic thermodynamics is formulated for variables that are odd under time reversal. The invariance under spatial rotation of the collision rates due to the isotropy of the heat bath is shown to be a crucial ingredient. An alternative…

Statistical Mechanics · Physics 2015-07-29 C. Van den Broeck , R. Toral

The behavior of interacting populations typically displays irregular temporal and spatial patterns that are difficult to reconcile with an underlying deterministic dynamics. A classical example is the heterogeneous distribution of plankton…

Populations and Evolution · Quantitative Biology 2009-11-13 M. H. Vainstein , J. M. Rubi , J. M. G. Vilar

The mobility of an overdamped particle, in a periodic potential tilted by a constant external field and moving in a medium with periodic friction coefficient is examined. When the potential and the friction coefficient have the same…

Statistical Mechanics · Physics 2009-10-31 Debasis Dan , Mangal C. Mahato , A. M. Jayannavar

The climate system is a forced, dissipative, nonlinear, complex and heterogeneous system that is out of thermodynamic equilibrium. The system exhibits natural variability on many scales of motion, in time as well as space, and it is subject…

Atmospheric and Oceanic Physics · Physics 2020-08-05 Michael Ghil , Valerio Lucarini

Atmospheric trace-gas inversion refers to any technique used to predict spatial and temporal fluxes using mole-fraction measurements and atmospheric simulations obtained from computer models. Studies to date are most often of a…

Spatial heterogeneity in the elastic properties of soft random solids is investigated via a two-pronged approach. First, a nonlocal phenomenological model for the elastic free energy is examined. This features a quenched random kernel,…

Disordered Systems and Neural Networks · Physics 2011-12-06 Xiaoming Mao , Paul M. Goldbart , Xiangjun Xing , Annette Zippelius

Spatial linear instability analysis is employed to investigate the instability of a viscoelastic liquid jet in a co-flowing gas stream. The theoretical model incorporates a non-uniform axial base profile represented by a hyperbolic tangent,…

Fluid Dynamics · Physics 2026-03-03 Jiawei Li , Ming Wang , Kai Mu , Zhaodong Ding , Ting Si

The two most commonly used methods to model the behaviour of granular flows are discrete element and continuum mechanics simulations. These approaches concentrate on the deterministic description of particle or bulk material motion. Unlike…

Soft Condensed Matter · Physics 2025-01-15 Benjy Marks , Shivakumar Athani , Itai Einav