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Related papers: Augmented unprojected Krylov subspace methods

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We propose algorithms for efficient time integration of large systems of oscillatory second order ordinary differential equations (ODEs) whose solution can be expressed in terms of trigonometric matrix functions. Our algorithms are based on…

Numerical Analysis · Mathematics 2023-04-07 M. A. Botchev , L. A. Knizhnerman , M. Schweitzer

The generalized minimal residual (GMRES) algorithm is applied to image reconstruction using linear computed tomography (CT) models. The GMRES algorithm iteratively solves square, non-symmetric linear systems and it has practical application…

Medical Physics · Physics 2022-05-04 Emil Y. Sidky , Per Christian Hansen , Jakob S. Jørgensen , Xiaochuan Pan

In this paper, we introduce an uplifted reduced order modeling (UROM) approach through the integration of standard projection based methods with long short-term memory (LSTM) embedding. Our approach has three modeling layers or components.…

Fluid Dynamics · Physics 2020-04-22 Shady E. Ahmed , Omer San , Adil Rasheed , Traian Iliescu

This paper presents an efficient algorithm to solve total variation (TV) regularizations of images contaminated by a both blur and noise. The unconstrained structure of the problem suggests that one can solve a constrained optimization…

Numerical Analysis · Computer Science 2018-02-13 A. Bentbib , M. El Guide , K. Jbilou

The hybrid LSMR algorithm is proposed for large-scale general-form regularization. It is based on a Krylov subspace projection method where the matrix $A$ is first projected onto a subspace, typically a Krylov subspace, which is implemented…

Numerical Analysis · Mathematics 2024-09-17 Yanfei Yang

This paper introduces new solvers for efficiently computing solutions to large-scale inverse problems with group sparsity regularization, including both non-overlapping and overlapping groups. Group sparsity regularization refers to a type…

Numerical Analysis · Mathematics 2023-06-16 Julianne Chung , Malena Sabaté Landman

Krylov subspace methods are a powerful family of iterative solvers for linear systems of equations, which are commonly used for inverse problems due to their intrinsic regularization properties. Moreover, these methods are naturally suited…

Nesterov's accelerated gradient methods (AGM) have been successfully applied in many machine learning areas. However, their empirical performance on training max-margin models has been inferior to existing specialized solvers. In this…

Machine Learning · Computer Science 2010-11-03 Xinhua Zhang , Ankan Saha , S. V. N. Vishwanathan

We develop and analyze an inexact regularized alternating projection method for nonconvex feasibility problems. Such a method employs inexact projections on one of the two sets, according to a set of well-defined conditions. We prove the…

Optimization and Control · Mathematics 2025-07-28 Stefania Bellavia , Simone Rebegoldi , Mattia Silei

An efficient Krylov subspace algorithm for computing actions of the $\varphi$ matrix function for large matrices is proposed. This matrix function is widely used in exponential time integration, Markov chains and network analysis and many…

Numerical Analysis · Mathematics 2020-10-20 Mike A. Botchev , Leonid A. Knizhnerman , Eugene E. Tyrtyshnikov

The discretization of convection-diffusion equations by implicit or semi-implicit methods leads to a sequence of linear systems usually solved by iterative linear solvers such as GMRES. Many techniques bearing the name of \emph{recycling…

Numerical Analysis · Mathematics 2018-07-26 Giuseppe Pitton , Luca Heltai

We present a new short-recurrence reaidual-optimal Krylov subspace recycling method for sequences of Hermitian systems of linear equations with a fixed system matrix and changing right-hand sides. Such sequences of linear systems occur…

Numerical Analysis · Mathematics 2016-04-15 Martin Peter Neuenhofen , Sven Groß

This paper presents a single-life reinforcement learning (SLRL) approach to adaptively select the dimension of the Krylov subspace during the generalized minimal residual (GMRES) iteration. GMRES is an iterative algorithm for solving large…

Computational Engineering, Finance, and Science · Computer Science 2025-02-04 Hadi Keramati , Feridun Hamdullahpur

Motivated by applications arising from sensor networks and machine learning, we consider the problem of minimizing a finite sum of nondifferentiable convex functions where each component function is associated with an agent and a…

Optimization and Control · Mathematics 2021-03-22 Harshal D. Kaushik , Farzad Yousefian

Krylov subspace methods are among the most efficient solvers for large scale linear algebra problems. Nevertheless, classic Krylov subspace algorithms do not scale well on massively parallel hardware due to synchronization bottlenecks.…

Distributed, Parallel, and Cluster Computing · Computer Science 2019-01-29 Jeffrey Cornelis , Siegfried Cools , Wim Vanroose

We address the inverse problem of cosmic large-scale structure reconstruction from a Bayesian perspective. For a linear data model, a number of known and novel reconstruction schemes, which differ in terms of the underlying signal prior,…

Astrophysics · Physics 2009-11-06 F. S. Kitaura , T. A. Ensslin

We present two minimum residual methods for solving sequences of shifted linear systems, the right-preconditioned shifted GMRES and shifted recycled GMRES algorithms which use a seed projection strategy often employed to solve multiple…

Numerical Analysis · Mathematics 2016-02-04 Kirk M. Soodhalter

This paper introduces a new class of algorithms for solving large-scale linear inverse problems based on new flexible and inexact Golub-Kahan factorizations. The proposed methods iteratively compute regularized solutions by approximating a…

Numerical Analysis · Mathematics 2025-10-22 Malena Sabaté Landman , Silvia Gazzola

We present SKA-SGD (Streaming Krylov-Accelerated Stochastic Gradient Descent), a novel optimization approach that accelerates convergence for ill-conditioned problems by projecting stochastic gradients onto a low-dimensional Krylov…

Numerical Analysis · Mathematics 2025-05-13 Stephen Thomas

This paper introduces new solvers for the computation of low-rank approximate solutions to large-scale linear problems, with a particular focus on the regularization of linear inverse problems. Although Krylov methods incorporating explicit…

Numerical Analysis · Mathematics 2019-11-05 Silvia Gazzola , Chang Meng , James Nagy