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Instead of sampling a function at a single point, average sampling takes the weighted sum of function values around the point. Such a sampling strategy is more practical and more stable. In this note, we present an explicit method with an…

Information Theory · Computer Science 2014-12-23 Wenjian Chen , Haizhang Zhang

We investigate the problems of 1-D and 2-D signal recovery from subsampled Hadamard measurements using Haar wavelet sparsity prior. These problems are of interest in, e.g., computational imaging applications relying on optical multiplexing…

Information Theory · Computer Science 2019-07-24 Amirafshar Moshtaghpour , José M. Bioucas Dias , Laurent Jacques

We report multipronged progress on the stochastic averaging approach to numerical analytic continuation of quantum Monte Carlo data. With the sampled spectrum parametrized with delta-functions in continuous frequency space, a calculation of…

Strongly Correlated Electrons · Physics 2023-01-11 Hui Shao , Anders W. Sandvik

In this work we propose and analyze a weighted proper orthogonal decomposition method to solve elliptic partial differential equations depending on random input data, for stochastic problems that can be transformed into parametric systems.…

Numerical Analysis · Mathematics 2023-08-08 Luca Venturi , Francesco Ballarin , Gianluigi Rozza

In this paper we propose an algorithm for recovering sparse orthogonal polynomials using stochastic collocation. Our approach is motivated by the desire to use generalized polynomial chaos expansions (PCE) to quantify uncertainty in models…

Numerical Analysis · Mathematics 2021-05-04 John D. Jakeman , Akil Narayan , Tao Zhou

A discretization scheme for variable coefficient elliptic PDEs in the plane is presented. The scheme is based on high-order Gaussian quadratures and is designed for problems with smooth solutions, such as scattering problems involving soft…

Numerical Analysis · Mathematics 2015-03-17 Per-Gunnar Martinsson

Unbalanced tabular data sets present significant challenges for predictive modeling and data analysis across a wide range of applications. In many real-world scenarios, such as fraud detection, medical diagnosis, and rare event prediction,…

Machine Learning · Computer Science 2025-07-23 Ivona Krchova , Michael Platzer , Paul Tiwald

We provide an a priori analysis of collocation methods for solving elliptic boundary value problems. They begin with information in the form of point values of the data and utilize only this information to numerically approximate the…

Numerical Analysis · Mathematics 2025-01-08 Andrea Bonito , Ronald DeVore , Guergana Petrova , Jonathan W. Siegel

The reconstruction of unknown functions from a finite number of samples is a fundamental challenge in pure and applied mathematics. This survey provides a comprehensive overview of recent developments in sampling recovery, focusing on the…

Numerical Analysis · Mathematics 2026-01-14 F. Dai , V. Temlyakov

We introduce a new iterative method for computing solutions of elliptic equations with random rapidly oscillating coefficients. Similarly to a multigrid method, each step of the iteration involves different computations meant to address…

Numerical Analysis · Mathematics 2020-03-31 S. Armstrong , A. Hannukainen , T. Kuusi , J. -C. Mourrat

Recent works have shown that deep neural networks can be employed to solve partial differential equations, giving rise to the framework of physics informed neural networks. We introduce a generalization for these methods that manifests as a…

Numerical Analysis · Mathematics 2021-03-25 Remco van der Meer , Cornelis Oosterlee , Anastasia Borovykh

Class imbalance in real-world data poses a common bottleneck for machine learning tasks, since achieving good generalization on under-represented examples is often challenging. Mitigation strategies, such as under or oversampling the data…

Disordered Systems and Neural Networks · Physics 2025-02-03 Emanuele Loffredo , Mauro Pastore , Simona Cocco , Rémi Monasson

Neural networks have shown significant potential in solving partial differential equations (PDEs). While deep networks are capable of approximating complex functions, direct one-shot training often faces limitations in both accuracy and…

Numerical Analysis · Mathematics 2025-03-10 Mingxing Weng , Zhiping Mao , Jie Shen

We present a multivariate Gaussian process regression approach for parameter field reconstruction based on the field's measurements collected at two different scales, the coarse and fine scales. The proposed approach treats the parameter…

Methodology · Statistics 2018-04-19 David A. Barajas-Solano , Alexandre M. Tartakovsky

We report a multiscale approach of broad applicability to stochastic reconstruction of multiphase materials, including porous ones. The approach devised uses an optimization method, such as the simulated annealing (SA) and the so-called…

Materials Science · Physics 2018-11-13 R. Piasecki , W. Olchawa , D. Frączek , R. Wiśniowski

This work describes a domain embedding technique between two non-matching meshes used for generating realizations of spatially correlated random fields with applications to large-scale sampling-based uncertainty quantification. The goal is…

Numerical Analysis · Mathematics 2017-12-20 Sarah Osborn , Patrick Zulian , Thomas Benson , Umberto Villa , Rolf Krause , Panayot S. Vassilevski

The best practical techniques for exact solution of instances of the constrained maximum-entropy sampling problem, a discrete-optimization problem arising in the design of experiments, are via a branch-and-bound framework, working with a…

Optimization and Control · Mathematics 2024-02-19 Zhongzhu Chen , Marcia Fampa , Jon Lee

This work presents a novel and effective method for fitting multidimensional ellipsoids to scattered data in the contamination of noise and outliers. We approach the problem as a Bayesian parameter estimate process and maximize the…

Methodology · Statistics 2024-07-30 Zhao Mingyang , Jia Xiaohong , Ma Lei , Shi Yuke , Jiang Jingen , Li Qizhai , Yan Dong-Ming , Huang Tiejun

We consider solving the $\ell_1$-regularized least-squares ($\ell_1$-LS) problem in the context of sparse recovery, for applications such as compressed sensing. The standard proximal gradient method, also known as iterative…

Optimization and Control · Mathematics 2012-03-15 Lin Xiao , Tong Zhang

We introduce a randomly extrapolated primal-dual coordinate descent method that adapts to sparsity of the data matrix and the favorable structures of the objective function. Our method updates only a subset of primal and dual variables with…

Optimization and Control · Mathematics 2020-07-14 Ahmet Alacaoglu , Olivier Fercoq , Volkan Cevher