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Related papers: Multi-Point Gradient Estimation in Turbulence

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We introduce an estimator for the curvature of curves and surfaces by using finite sample points drawn from sampling a probability distribution that has support on the curve or surface. First we give an algorithm for estimation of the…

Differential Geometry · Mathematics 2025-07-03 R. Mirzaie

The recent development of the Velocity Gradient Technique allows observers to map magnetic field orientations and magnetization using the direction of velocity gradients. Aside from the directions, amplitudes of velocity gradients also…

Astrophysics of Galaxies · Physics 2020-05-15 Ka Ho Yuen , A. Lazarian

Robust estimators and different filtering techniques are proposed and their impact on the determination of a wide range of turbulence quantities is analysed. High-frequency water level measurements in a stepped spillway are used as a case…

Fluid Dynamics · Physics 2023-07-13 Daniel Valero , Hubert Chanson , Daniel B. Bung

There are several applications of stochastic optimization where one can benefit from a robust estimate of the gradient. For example, domains such as distributed learning with corrupted nodes, the presence of large outliers in the training…

Machine Learning · Statistics 2025-10-30 Fabian Schaipp , Guillaume Garrigos , Umut Simsekli , Robert Gower

Controlling UAV flights precisely requires a realistic dynamic model and accurate state estimates from onboard sensors like UAV, GPS and visual observations. Obtaining a precise dynamic model is extremely difficult, as important aerodynamic…

Robotics · Computer Science 2022-03-29 Quentin Possamaï , Steeven Janny , Madiha Nadri , Laurent Bako , Christian Wolf

Turbulent fluid flows exhibit a complex small-scale structure with frequently occurring extreme velocity gradients. Particles probing such swirling and straining regions respond with an intricate shape-dependent orientational dynamics,…

Fluid Dynamics · Physics 2020-11-30 Leonhard A. Leppin , Michael Wilczek

Turbulence in curved spacetimes in general, and in the vicinity of black holes (BHs) in particular, represents a poorly understood phenomenon that is often analysed employing techniques developed for flat spacetimes. We here propose a novel…

General Relativity and Quantum Cosmology · Physics 2025-11-19 Rita Megale , Alejandro Cruz-Osorio , Giuseppe Ficarra , Mario Imbrogno , Claudio Meringolo , Leonardo Primavera , Luciano Rezzolla , Sergio Servidio

We show how to use numerical methods within the framework of successive scaling to analyse the microstructure of turbulence, in particular to find inertial range exponents and structure functions. The methods are first calibrated on the…

Numerical Analysis · Mathematics 2007-05-23 Panagiotis Stinis , Alexandre J. Chorin

In this preliminary study, we provide two methods for estimating the gradients of functions of real value. Both methods are built on derivative estimations that are calculated using the standard method or the Squire-Trapp method for any…

Numerical Analysis · Mathematics 2023-12-04 Ergun Akleman , Alan Freed

To achieve point cloud denoising, traditional methods heavily rely on geometric priors, and most learning-based approaches suffer from outliers and loss of details. Recently, the gradient-based method was proposed to estimate the gradient…

Computer Vision and Pattern Recognition · Computer Science 2023-06-27 Yaping Zhao , Haitian Zheng , Zhongrui Wang , Jiebo Luo , Edmund Y. Lam

In many natural and industrial applications, turbulent flows encompass some form of dispersed particles. Although this type of multiphase turbulent flow is omnipresent, its numerical modeling has proven to be a remarkably challenging…

Fluid Dynamics · Physics 2024-07-02 Xander M. de Wit , Rudie P. J. Kunnen , Herman J. H. Clercx , Federico Toschi

The instant Lagranian coordinator system is used to describe the fluid material motion. By this way, the instant deformation gradient (expressed by spatial velocity gradient) concept is established. Based on this geometrical understanding,…

Fluid Dynamics · Physics 2007-05-23 Jianhua Xiao

We study gradient magnetometry with an ensemble of atoms with arbitrary spin. We calculate precision bounds for estimating the gradient of the magnetic field based on the quantum Fisher information. For quantum states that are invariant…

Quantum Physics · Physics 2018-06-08 Iagoba Apellaniz , Inigo Urizar-Lanz , Zoltan Zimboras , Philipp Hyllus , Geza Toth

Engineering design and scientific analysis rely upon computer simulations of turbulent fluid flows using turbulence models. These turbulence models are empirical and approximate, leading to large uncertainties in their predictions that…

Fluid Dynamics · Physics 2024-05-28 Minghan Chu , Weicheng Qian

Prediction is a fundamental objective of science. It is more difficult for chaotic and complex systems like turbulence. Here we use information theory to quantify spatial prediction using experimental data from a turbulent soap film. At…

Fluid Dynamics · Physics 2014-12-05 Rory Cerbus , Walter Goldburg

Grid turbulence is investigated using cross-correlation digital Particle Image Velocimetry (PIV) over a range of Taylor Reynolds Number (Re{\lambda}) from 5 to 44. Instantaneous velocity is measured directly and vorticity and velocity…

Fluid Dynamics · Physics 2021-03-16 Philippa O'Neill , David Nicolaides , Damon Honnery , Julio Soria

Predictive geometric models deliver excellent results for many Machine Learning use cases. Despite their undoubted performance, neural predictive algorithms can show unexpected degrees of instability and variance, particularly when applied…

Machine Learning · Computer Science 2018-07-20 Michaela Regneri , Malte Hoffmann , Jurij Kost , Niklas Pietsch , Timo Schulz , Sabine Stamm

This paper aims at achieving a "good" estimator for the gradient of a function on a high-dimensional space. Often such functions are not sensitive in all coordinates and the gradient of the function is almost sparse. We propose a method for…

Machine Learning · Statistics 2016-07-27 Vivek S. Borkar , Vikranth R. Dwaracherla , Neeraja Sahasrabudhe

We develop a general theory to estimate magnetic field gradients in quantum metrology. We consider a system of $N$ particles distributed on a line whose internal degrees of freedom interact with a magnetic field. Usually gradient estimation…

Quantum Physics · Physics 2017-10-30 Sanah Altenburg , Michał Oszmaniec , Sabine Wölk , Otfried Gühne

Estimates of image gradients play a ubiquitous role in image segmentation and classification problems since gradients directly relate to the boundaries or the edges of a scene. This paper proposes an unified approach to gradient estimation…

Computer Vision and Pattern Recognition · Computer Science 2016-05-10 Anish Acharya , Uddipan Mukherjee , Charless Fowlkes
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