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We propose an adaptive refinement algorithm to solve total variation regularized measure optimization problems. The method iteratively constructs dyadic partitions of the unit cube based on i) the resolution of discretized dual problems and…

Optimization and Control · Mathematics 2023-01-19 Axel Flinth , Frédéric de Gournay , Pierre Weiss

We propose and analyze a two-level method for mimetic finite difference approximations of second order elliptic boundary value problems. We prove that the two-level algorithm is uniformly convergent, i.e., the number of iterations needed to…

Numerical Analysis · Mathematics 2014-10-14 Paola F. Antonietti , Marco Verani , Ludmil Zikatanov

A local weighted discontinuous Galerkin gradient discretization method for solving elliptic equations is introduced. The local scheme is based on a coarse grid and successively improves the solution solving a sequence of local elliptic…

Numerical Analysis · Mathematics 2018-07-30 Assyr Abdulle , Giacomo Rosilho de Souza

Despite recent progress in diffusion models, generating realistic head portraits from novel viewpoints remains a significant challenge. Most current approaches are constrained to limited angular ranges, predominantly focusing on frontal or…

Computer Vision and Pattern Recognition · Computer Science 2025-09-24 Stathis Galanakis , Alexandros Lattas , Stylianos Moschoglou , Bernhard Kainz , Stefanos Zafeiriou

A parallel dynamic overset framework has been developed for the curvilinear immersed boundary (overset-CURVIB) method to enable tackling a wide range of challenging flow problems. The dynamic overset grids are used to locally increase the…

Computational Engineering, Finance, and Science · Computer Science 2019-10-22 Mohammadali Hedayat , Iman Borazjani

Various classes of stable finite difference schemes can be constructed to obtain a numerical solution. It is important to select among all stable schemes such a scheme that is optimal in terms of certain additional criteria. In this study,…

Numerical Analysis · Computer Science 2010-06-01 Petr N. Vabishchevich

We propose a method to address challenges in unconstrained face detection, such as arbitrary pose variations and occlusions. First, a new image feature called Normalized Pixel Difference (NPD) is proposed. NPD feature is computed as the…

Computer Vision and Pattern Recognition · Computer Science 2015-09-08 Shengcai Liao , Anil K. Jain , Stan Z. Li

We consider variational problems that model the bending behavior of curves that are constrained to belong to given hypersurfaces. Finite element discretizations of corresponding functionals are justified rigorously via Gamma-convergence.…

Numerical Analysis · Mathematics 2020-04-24 Sören Bartels

This paper introduces a numerical approach to solve singularly perturbed convection diffusion boundary value problems for second-order ordinary differential equations that feature a small positive parameter {\epsilon} multiplying the…

Numerical Analysis · Mathematics 2023-06-14 Daniel T. Gregory

In this work, we propose and develop efficient and accurate numerical methods for solving the Kirchhoff-Love plate model in domains with complex geometries. The algorithms proposed here employ curvilinear finite-difference methods for…

Numerical Analysis · Mathematics 2021-05-13 Longfei Li , Hangjie Ji , Qi Tang

Divergence and vorticity damping, which operate upon horizontal divergence and relative vorticity, are explicit diffusion mechanisms used in dynamical cores to ensure stability. To avoid numerical blow-up from excessively strong diffusion,…

Numerical Analysis · Mathematics 2026-02-19 Timothy C. Andrews , Christiane Jablonowski

In this paper we develop finite difference schemes for elliptic problems with piecewise continuous coefficients that have (possibly huge) jumps across fixed internal interfaces. In contrast with such problems involving one smooth…

Numerical Analysis · Mathematics 2023-02-21 Qiwei Feng , Bin Han , Peter Minev

In theory, diffusion curves promise complex color gradations for infinite-resolution vector graphics. In practice, existing realizations suffer from poor scaling, discretization artifacts, or insufficient support for rich boundary…

Numerical Analysis · Mathematics 2023-11-27 Seungbae Bang , Kirill Serkh , Oded Stein , Alec Jacobson

In this paper, we propose an efficient numerical scheme for the approximate solution of the time fractional diffusion-wave equation with reaction term based on cubic trigonometric basis functions. The time fractional derivative is…

Numerical Analysis · Mathematics 2017-05-24 Muhammad Abbas

Diffusion Purification, purifying noised images with diffusion models, has been widely used for enhancing certified robustness via randomized smoothing. However, existing frameworks often grapple with the balance between efficiency and…

Computer Vision and Pattern Recognition · Computer Science 2024-07-02 Yiquan Li , Zhongzhu Chen , Kun Jin , Jiongxiao Wang , Bo Li , Chaowei Xiao

We introduce a new general-purpose approach to deep learning on 3D surfaces, based on the insight that a simple diffusion layer is highly effective for spatial communication. The resulting networks are automatically robust to changes in…

Computer Vision and Pattern Recognition · Computer Science 2022-01-10 Nicholas Sharp , Souhaib Attaiki , Keenan Crane , Maks Ovsjanikov

We present a novel approach of discretizing variable coefficient diffusion operators in the context of meshfree generalized finite difference methods. Our ansatz uses properties of derived operators and combines the discrete Laplace…

Numerical Analysis · Mathematics 2024-06-21 Heinrich Kraus , Jörg Kuhnert , Pratik Suchde

Time fractional advection-dispersion equations arise as generalizations of classical integer order advection-dispersion equations and are increasingly used to model fluid flow problems through porous media. In this paper we develop an…

Numerical Analysis · Mathematics 2019-05-16 Carlos E. Mejía , Alejandro Piedrahita

We propose to augment standard grid-based fluid solvers with pointwise divergence-free velocity interpolation, thereby ensuring exact incompressibility down to the sub-cell level. Our method takes as input a discretely divergence-free…

Graphics · Computer Science 2023-11-28 Jumyung Chang , Ruben Partono , Vinicius C. Azevedo , Christopher Batty

We prove optimal error bounds for a second order in time finite element approximation of curve shortening flow in possibly higher codimension. In addition, we introduce a second order in time method for curve diffusion. Both schemes are…

Numerical Analysis · Mathematics 2026-01-29 Klaus Deckelnick , Robert Nürnberg