Publications related to Del in cylindrical and spherical coordinates

High-order accurate entropy stable adaptive moving mesh finite difference schemes for special relativistic (magneto)hydrodynamics

This paper develops high-order accurate entropy stable (ES) adaptive moving mesh finite difference schemes for the two- and three-dimensional special relativistic hydrodynamic (RHD) and magnetohydrodynamic (RMHD) equations, which is the high-order accurate ...

ACADEMIC PRESS INC ELSEVIER SCIENCE2022

Local invertibility and sensitivity of atomic structure-feature mappings

Michele Ceriotti, Sergey Pozdnyakov

Background: The increasingly common applications of machine-learning schemes to atomic-scale simulations have triggered efforts to better understand the mathematical properties of the mapping between the Cartesian coordinates of the atoms and the variety o ...

2021

Method and system for generating a three-dimensional model based on spherical photogrammetry

Frédéric Kaplan, Pierre-André Mudry, Nils Hamel, Albane Bénédicte Descombes

A computer-implemented method is proposed for creating a three-dimensional model of the environment. The method comprises the steps of planning (105) a trajectory for a moving system carrying an omnidirectional camera comprising a first image sensor facing ...

2021

Physics-Inspired Structural Representations for Molecules and Materials

Michele Ceriotti, Félix Benedito Clément Musil, Andrea Grisafi

The first step in the construction of a regression model or a data-driven analysis, aiming to predict or elucidate the relationship between the atomic-scale structure of matter and its properties, involves transforming the Cartesian coordinates of the atom ...

AMER CHEMICAL SOC2021

Functional Inverse Problems on Spheres: Theory, Algorithms and Applications

Matthieu Martin Jean-André Simeoni

Many scientific inquiries in natural sciences involve approximating a spherical field -namely a scalar quantity defined over a continuum of directions- from generalised samples of the latter (e.g. directional samples, local averages, etc). Such an approxim ...

EPFL2020

Instanton theory of ground-state tunneling splittings with general paths

Christophe Louis Joseph Jean-Luc Vaillant, Mihael Erakovic

We derive a multidimensional instanton theory for calculating ground-state tunneling splittings in Cartesian coordinates for general paths. It is an extension of the method by Mil'nikov and Nakamura [J. Chem. Phys. 115, 6881 (2001)] to include asymmetric p ...

2020

Modeling robot geometries like molecules, application to fast multi-contact posture planning for humanoids

Auke Ijspeert, Salman Faraji

Traditional joint-space models used to describe equations of motion for humanoid robots offer nice properties linked directly to the way these robots are built. However, from a computational point of view and convergence properties, these models are not th ...

Ieee-Inst Electrical Electronics Engineers Inc2018

Hybrid guiding-centre/full-orbit simulations in non-axisymmetric magnetic geometry exploiting general criterion for guiding-centre accuracy

Jonathan Graves, Wilfred Anthony Cooper, David Pfefferlé

To identify under what conditions guiding-centre or full-orbit tracing should be used, an estimation of the spatial variation of the magnetic field is proposed, not only taking into account gradient and curvature terms but also parallel currents and the lo ...

Iop Publishing Ltd2015

Flow separation at convex banks in open channels

Koen Blanckaert

Laboratory experiments in an open channel bend provide insight into the physics of convex bank flow separation occurring in a variety of channel configurations, including confluences and bifurcations. The edge of the zone of flow separation is characterize ...

Cambridge University Press2015

A stabilized finite volume element formulation for sedimentation-consolidation processes

Ricardo Esteban Ruiz Baier

A model of sedimentation-consolidation processes in so-called clarifier-thickener units is given by a parabolic equation describing the evolution of the local solids concentration coupled with a version of the Stokes system for an incompressible fluid desc ...

Siam Publications2012

Spherical 3D isotropic wavelets

Anaïs Marie Rassat, Jean-Luc Starck

Context. Future cosmological surveys will provide 3D large scale structure maps with large sky coverage, for which a 3D spherical Fourier-Bessel (SFB) analysis in spherical coordinates is natural. Wavelets are particularly well-suited to the analysis and d ...

2012

Intrinsic advantages of the w component and spherical imaging for wide-field radio interferometry

Yves Wiaux, Jason Douglas McEwen

Incorporating wide-field considerations in interferometric imaging is of increasing importance for next-generation radio telescopes. Compressed sensing techniques for interferometric imaging have been extended to wide fields recently, recovering images in ...

2011

Dynamic Visual Attention on the Sphere

Pierre-André Farine, Iva Bogdanova Vandergheynst, Heinz Hügli, Alexandre Bur

In this paper we present a computational model of dynamic visual attention on the sphere which combines static (intensity,chromaticity, orientation) and motion features in order to detect salient locations in omnidirectional image sequences while working d ...

Elsevier2010

Conformational analysis of nucleic acids revisited: Curves

John Maddocks, Daiva Petkeviciute

We describe Curves+, a new nucleic acid conformational analysis program which is applicable to a wide range of nucleic acid structures, including those with up to four strands and with either canonical or modified bases and backbones. The program is algori ...

Oxford University Press2009

Some Issues on the p-Laplace Equation in Cylindrical Domains

We investigate the asymptotic behavior of the solution to equations of the p-Laplacian type in cylindrical domains becoming unbounded and address some issues regarding the solution in unbounded domains. ...

2008

Axisymmetric swirling flow simulation of the draft tube vortex in Francis turbines at partial discharge

François Avellan

The flow in the draft tube cone of Francis turbines operated at partial discharge is a complex hydrodynamic phenomenon where an incoming steady axisymmetric swirling flow evolves into a three-dimensional unsteady flow field with precessing helical vortex ( ...

International Association For Hydraulic Research2008

Dense Disparity Estimation from Omnidirectional Images

Pascal Frossard, Zafer Arican

This paper addresses the problem of dense estimation of disparities between omnidirectional images, in a spherical framework. Omnidirectional imaging certainly represents important advantages for the representation and processing of the plenoptic function ...

2007

A multi-colour sensitive device for color image sensing

Michael Graetzel, Udo Bach

A sensor element (1, 20, 21, 22) capable of sensing more than one spectral band of electromagnetic radiation with the same (x-y) spatial location, especially where the dimensions x-y-z form a set of Cartesian coordinates with z parallel to the direction of ...

2006