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Related papers: A data-driven approach for 2D vorticity PDF equati…

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We investigate the behavior of the magnetic pressure, $b^2$, in fully turbulent MHD flows in ``1+2/3'' dimensions by means of its effect on the probability density function (PDF) of the density field. We start by reviewing our previous…

Astrophysics · Physics 2007-05-23 Enrique Vazquez-Semadeni , Thierry Passot

The streaming model describes the mapping between real and redshift space for 2-point clustering statistics. Its key element is the probability density function (PDF) of line-of-sight pairwise peculiar velocities. Following a kinetic-theory…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-24 Joseph Kuruvilla , Cristiano Porciani

We develop an iterative (greedy) deep learning (DL) algorithm which is able to transform an arbitrary probability distribution function (PDF) into the target PDF. The model is based on iterative Optimal Transport of a series of 1D slices,…

Machine Learning · Computer Science 2021-06-16 Biwei Dai , Uros Seljak

In this paper hyperbolic partial differential equations with random coefficients are discussed. Such random partial differential equations appear for instance in traffic flow problems as well as in many physical processes in random media.…

Analysis of PDEs · Mathematics 2017-06-19 Andrea Barth , Franz G. Fuchs

Data-Driven Computational Mechanics is a novel computing paradigm that enables the transition from standard data-starved approaches to modern data-rich approaches. At this early stage of development, one can distinguish two mainstream…

Numerical Analysis · Mathematics 2019-10-29 Cristian Guillermo Gebhardt , Dominik Schillinger , Marc Christian Steinbach , Raimund Rolfes

The local streamline topology classification method of Chong et al. (1990) is adapted and extended to describe the geometry of infinitesimal vortex lines. Direct numerical simulation (DNS) data of forced isotropic turbulence reveals that…

Fluid Dynamics · Physics 2023-06-22 Bajrang Sharma , Rishita Das , Sharath S. Girimaji

A method providing optimal estimate of probability density functions (PDFs) from time series is proposed. It allows almost arbitrary resolution PDFs when applied to either, sampled analytic functions or digitized data from experiments. When…

Data Analysis, Statistics and Probability · Physics 2007-05-30 R. Labbé

A new class of analytical 2-D solutions of the full set of the steady magnetohydrodynamic (MHD) equations, describing an axisymmetric helicoidal magnetized outflow originating from a rotating central object, is presented. The solutions are…

Astrophysics · Physics 2009-11-06 J. J. G. Lima , E. R. Priest , K. Tsinganos

In the present paper, an aerodynamic investigation of a high-speed train is performed. In the first section of this article, a generic high-speed train against a turbulent flow is simulated, numerically. The Reynolds-Averaged Navier-Stokes…

In this paper we address the derivation of causal relativistic hydrodynamics, formulated within the framework of Divergence Type Theories (DTTs), from kinetic theory for spinless particles obeying Fermi-Dirac statistics. The approach leads…

High Energy Physics - Phenomenology · Physics 2017-05-03 Milton Aguilar , Esteban Calzetta

A transport equation with a non-smooth velocity field is considered under inhomogeneous Dirichlet boundary conditions. The spatial gradient of the velocity field is assumed in $L^{p'}$ in space and the divergence of the velocity field is…

Analysis of PDEs · Mathematics 2025-01-23 Tokuhiro Eto , Yoshikazu Giga

The analytical formalism to obtain the probability distribution functions (PDFs) of spherically-averaged cosmic densities and velocity divergences in the mildly non-linear regime is presented. A large-deviation principle is applied to those…

Cosmology and Nongalactic Astrophysics · Physics 2017-08-03 Cora Uhlemann , Sandrine Codis , Oliver Hahn , Christophe Pichon , Francis Bernardeau

We review various methods used to estimate uncertainties in quantum correlation functions, such as parton distribution functions (PDFs). Using a toy model of a PDF, we compare the uncertainty estimates yielded by the traditional Hessian and…

High Energy Physics - Phenomenology · Physics 2022-08-17 N. T. Hunt-Smith , A. Accardi , W. Melnitchouk , N. Sato , A. W. Thomas , M. J. White

In this work, we discuss some points relevant for stochastic modelling of one- and two-phase turbulent flows. In the framework of stochastic modelling, also referred to PDF approach, we propose a new Langevin model including all viscosity…

Fluid Dynamics · Physics 2010-09-14 Sergio Chibbaro , Jean-Pierre Minier

Intermittency in MHD turbulence has been analyzed using high resolution 2D numerical simulations. We show that the Probability Distribution Functions (PDFs) of the fluctuations of the Elsasser fields, magnetic field and velocity field…

Chaotic Dynamics · Physics 2015-06-26 L. Sorriso-Valvo , V. Carbone , P. Veltri , H. Politano , A. Pouquet

Atmospheric wind speeds and their fluctuations at different locations (onshore and offshore) are examined. One of the most striking features is the marked intermittency of probability density functions (PDF) of velocity differences -- no…

Adaptation and Self-Organizing Systems · Physics 2007-05-23 F. Böttcher , St. Barth , J. Peinke

We investigate the single-point probability density function of the velocity in three-dimensional stationary and decaying homogeneous isotropic turbulence. To this end we apply the statistical framework of the Lundgren-Monin-Novikov…

Fluid Dynamics · Physics 2011-07-04 Michael Wilczek , Anton Daitche , Rudolf Friedrich

Turbulence is a complex phenomenon that plays a critical role in the interstellar medium (ISM). Previous simulations and observations show that the probability density function (PDF) of gas density in isothermal and compressible systems…

Astrophysics of Galaxies · Physics 2025-03-26 Xunchuan Liu

This paper introduces an optimization problem (P) and a solution strategy to design variable-speed-limit controls for a highway that is subject to traffic congestion and uncertain vehicle arrival and departure. By employing a finite…

Optimization and Control · Mathematics 2020-09-08 Dan Li , Dariush Fooladivanda , Sonia Martinez

Inertial particle data from three-dimensional direct numerical simulations of particle-laden homogeneous isotropic turbulence at high Reynolds number are analyzed using Voronoi tessellation of the particle positions, considering different…

Fluid Dynamics · Physics 2020-11-12 Thibault Oujia , Keigo Matsuda , Kai Schneider
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