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In this work, an efficient blackbox-type multigrid method is proposed for solving multipoint flux approximations of the Darcy problem on logically rectangular grids. The approach is based on a cell-centered multigrid algorithm, which…

Numerical Analysis · Mathematics 2024-02-13 Andrés Arrarás , Francisco J. Gaspar , Laura Portero , Carmen Rodrigo

Consider the Fourier transform on the group $GL(2,R)$ of real $2\times 2$-matrices. We show that Fourier-images of polynomial differential operators on $GL(2,R)$ are differential-difference operators with coefficients meromorphic in…

Representation Theory · Mathematics 2019-10-29 Yury A. Neretin

We introduce a new numerical method, based on Bernoulli polynomials, for solving multiterm variable-order fractional differential equations. The variable-order fractional derivative was considered in the Caputo sense, while the…

Numerical Analysis · Mathematics 2021-11-18 Somayeh Nemati , Pedro M. Lima , Delfim F. M. Torres

Some mathematical models of applied problems lead to the need of solving boundary value problems with a fractional power of an elliptic operator. In a number of works, approximations of such a nonlocal operator are constructed on the basis…

Numerical Analysis · Computer Science 2019-05-28 Petr N. Vabishchevich

Given a set of $n$ sites from $\mathbb{R}^d$, each having some positive weight factor, the Multiplicatively Weighted Voronoi Diagram is a subdivision of space that associates each cell to the site whose weighted Euclidean distance is…

Computational Geometry · Computer Science 2024-03-19 Joachim Gudmundsson , Martin P. Seybold , Sampson Wong

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

This work focuses on developing methods for approximating the solution operators of a class of parametric partial differential equations via neural operators. Neural operators have several challenges, including the issue of generating…

Numerical Analysis · Mathematics 2023-11-17 Prashant K. Jha

While it is widely known that neural networks are universal approximators of continuous functions, a less known and perhaps more powerful result is that a neural network with a single hidden layer can approximate accurately any nonlinear…

Machine Learning · Computer Science 2021-11-03 Lu Lu , Pengzhan Jin , George Em Karniadakis

We present a simple wavefront-like approach for computing multiplicatively weighted Voronoi diagrams of points and straight-line segments in the Euclidean plane. If the input sites may be assumed to be randomly weighted points then the use…

Computational Geometry · Computer Science 2020-06-26 Martin Held , Stefan de Lorenzo

Visually sorted grid layouts provide an efficient method for organizing high-dimensional vectors in two-dimensional space by aligning spatial proximity with similarity relationships. This approach facilitates the effective sorting of…

Computer Vision and Pattern Recognition · Computer Science 2025-03-05 Kai Uwe Barthel , Florian Tim Barthel , Peter Eisert , Nico Hezel , Konstantin Schall

One of the main challenges in using deep learning-based methods for simulating physical systems and solving partial differential equations (PDEs) is formulating physics-based data in the desired structure for neural networks. Graph neural…

In this paper we consider an orthonormal basis, generated by a tensor product of Fourier basis functions, half period cosine basis functions, and the Chebyshev basis functions. We deal with the approximation problem in high dimensions…

Numerical Analysis · Mathematics 2024-04-26 Daniel Potts , Pascal Schröter

We investigate the typical cells $\widehat{Z}$ and $\widehat{Z}^\prime$ of $\beta$- and $\beta'$-Voronoi tessellations in $\mathbb{R}^d$, establishing a Complementary Theorem which entails: 1) a gamma distribution of the $\Phi$-content (a…

Probability · Mathematics 2025-04-01 Gilles Bonnet , Joseph Gordon

We investigate algorithms with predictions in computational geometry, specifically focusing on the basic problem of computing 2D Delaunay triangulations. Given a set $P$ of $n$ points in the plane and a triangulation $G$ that serves as a…

Computational Geometry · Computer Science 2026-01-14 Sergio Cabello , Timothy M. Chan , Panos Giannopoulos

Accuracy of a simulation is strongly depend on the grid quality. Here, quality means orthogonality at the boundaries and quasi-orthogonality within the critical regions, smoothness, bounded aspect ratios, solution adaptive behaviour, etc.…

Numerical Analysis · Mathematics 2007-05-23 sanjay kumar khattri

We consider an extension of the triangular-distance Delaunay graphs (TD-Delaunay) on a set $P$ of points in the plane. In TD-Delaunay, the convex distance is defined by a fixed-oriented equilateral triangle $\triangledown$, and there is an…

Computational Geometry · Computer Science 2014-09-22 Ahmad Biniaz , Anil Maheshwari , Michiel Smid

In this paper, we propose a novel space partitioning strategy for implicit hierarchy visualization such that the new plot not only has a tidy layout similar to the treemap, but also is flexible to data changes similar to the Voronoi…

Data Structures and Algorithms · Computer Science 2020-09-17 Yan-Chao Wang , Feng Lin , Hock-Soon Seah

We develop theory and software for rotation equivariant operators on scalar and vector fields, with diverse applications in simulation, optimization and machine learning. Rotation equivariance (covariance) means all fields in the system…

Machine Learning · Computer Science 2022-08-08 Paul Shen , Michael Herbst , Venkat Viswanathan

Let $P$ be a planar set of $n$ sites in general position. For $k\in\{1,\dots,n-1\}$, the Voronoi diagram of order $k$ for $P$ is obtained by subdividing the plane into cells such that points in the same cell have the same set of nearest $k$…

Computational Geometry · Computer Science 2018-10-02 Bahareh Banyassady , Matias Korman , Wolfgang Mulzer , André van Renssen , Marcel Roeloffzen , Paul Seiferth , Yannik Stein

We investigate the problem of image retrieval based on visual queries when the latter comprise arbitrary regions-of-interest (ROI) rather than entire images. Our proposal is a compact image descriptor that combines the state-of-the-art in…

Computer Vision and Pattern Recognition · Computer Science 2017-03-22 Aaron Chadha , Yiannis Andreopoulos