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Modeling membrane interactions with arbitrarily shaped colloidal particles, such as environmental micro- and nanoplastics, at the cell scale remains particularly challenging, owing to the complexity of particle geometries and the need to…

Soft Condensed Matter · Physics 2025-09-15 Didarul Ahasan Redwan , Justin Reicher , Xin Yong

In this paper we consider a shape optimization problem for the minimization of the erosion, that is caused by the impact of inert particles onto the walls of a bended pipe. Using the continuous adjoint approach, we formally compute the…

Optimization and Control · Mathematics 2019-08-14 Raphael Hohmann , Christian Leithäuser

Adjoint-based shape optimization most often relies on Eulerian flow field formulations. However, since Lagrangian particle methods are the natural choice for solving sedimentation problems in oceanography, extensions to the Lagrangian…

Fluid Dynamics · Physics 2022-09-07 Luka Schlegel , Volker Schulz

Many computational algorithms applied to geometry operate on discrete representations of shape. It is sometimes necessary to first simplify, or coarsen, representations found in modern datasets for practicable or expedited processing. The…

Computational Geometry · Computer Science 2023-02-10 Alexandros Dimitrios Keros , Kartic Subr

Electron self-injection and acceleration until dephasing in the blowout regime is studied for a set of initial conditions typical of recent experiments with 100 terawatt-class lasers. Two different approaches to computationally efficient,…

Advanced stellarators are typically optimized in two stages. The plasma equilibrium is optimized first, followed by the design of coils/permanent magnets. However, the coils/permanent magnets in the second stage may become too complex to…

Plasma Physics · Physics 2024-05-01 Guodong Yu , Ke Liu , Tianyi Qian , Yidong Xie , Xianyi Nie , Caoxiang Zhu

A gradient-based method for shape optimization problems constrained by the acoustic wave equation is presented. The method makes use of high-order accurate finite differences with summation-by-parts properties on multiblock curvilinear…

Numerical Analysis · Mathematics 2024-05-09 Gustav Eriksson , Vidar Stiernström

This article introduces a novel method for the implementation of shape optimisation with Lipschitz domains. We propose to use the shape derivative to determine deformation fields which represent steepest descent directions of the shape…

Optimization and Control · Mathematics 2021-12-15 Klaus Deckelnick , Philip J. Herbert , Michael Hinze

Variational data assimilation technique applied to identification of optimal approximations of derivatives near boundary is discussed in frames of one-dimensional wave equation. Simplicity of the equation and of its numerical scheme allows…

Mathematical Physics · Physics 2015-05-13 Eugene Kazantsev

In this paper, we propose a new set of midpoint-based high-order discretization schemes for computing straight and mixed nonlinear second derivative terms that appear in the compressible Navier-Stokes equations. Firstly, we detail a set of…

Numerical Analysis · Mathematics 2024-06-04 Hemanth Chandravamsi , Steven H. Frankel

A new global two-fluid electromagnetic turbulence code, CENTORI, has been developed for the purpose of studying magnetically-confined fusion plasmas on energy confinement timescales. This code is used to evolve the combined system of…

Computational Physics · Physics 2015-05-30 P. J. Knight , A. Thyagaraja , T. D. Edwards , J. Hein , M. Romanelli , K. G. McClements

Introduction High performance gradients poses a promise for breast diffusion weighted imaging (DWI) but are restricted by physiological limits in whole body scanners. While local nonlinear coils offer higher amplitudes, they often suffer…

A two-dimensional particle-in-cell code for simulation of low-frequency electromagnetic processes in laboratory plasmas has been developed. The code uses the Darwin method omitting the electromagnetic wave propagation. The Darwin method…

Modern product design in the engineering domain is increasingly driven by computational analysis including finite-element based simulation, computational optimization, and modern data analysis techniques such as machine learning. To apply…

Computer Vision and Pattern Recognition · Computer Science 2020-03-20 Skylar Sible , Rodrigo Iza-Teran , Jochen Garcke , Nikola Aulig , Patricia Wollstadt

We develop a method for calculating the equilibrium properties of the liquid-solid phase transition in a classical, ideal, multi-component plasma. Our method is a semi-analytic calculation that relies on extending the accurate fitting…

Solar and Stellar Astrophysics · Physics 2012-07-31 Zach Medin , Andrew Cumming

The free electron model with Boltzmann statistics for spherical low-density plasmas is developed further with asymptotic relations obtaining the density of electrons, mass densities, and the potentials of such plasmas. Solutions are…

Astrophysics of Galaxies · Physics 2024-06-28 Y. Ben-Aryeh

We consider a variational convex relaxation of a class of optimal partitioning and multiclass labeling problems, which has recently proven quite successful and can be seen as a continuous analogue of Linear Programming (LP) relaxation…

Computer Vision and Pattern Recognition · Computer Science 2011-12-06 Jan Lellmann , Frank Lenzen , Christoph Schnörr

A new reformulation of a free boundary problem for the Stokes equations governing a viscous flow with overdetermined condition on the free boundary is proposed. The idea of the method is to transform the governing equations to a boundary…

Optimization and Control · Mathematics 2023-02-24 Julius Fergy T. Rabago , Hirofumi Notsu

We present a new fast solver to calculate fixed-boundary plasma equilibria in toroidally axisymmetric geometries. By combining conformal mapping with Fourier and integral equation methods on the unit disk, we show that high-order accuracy…

Computing accurate splines of degree greater than three is still a challenging task in today's applications. In this type of interpolation, high-order derivatives are needed on the given mesh. As these derivatives are rarely known and are…

Numerical Analysis · Mathematics 2023-03-20 A. Pepin , S. Léger , N. Beaudoin