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For many applications involving a sequence of linear systems with slowly changing system matrices, subspace recycling, which exploits relationships among systems and reuses search space information, can achieve huge gains in iterations…

Numerical Analysis · Mathematics 2023-06-28 Misha E. Kilmer , Eric de Sturler

This paper is concerned with the regularization of large-scale discrete inverse problems by means of inexact Krylov methods. Specifically, we derive two new inexact Krylov methods that can be efficiently applied to unregularized or…

Numerical Analysis · Mathematics 2021-05-18 Silvia Gazzola , Malena Sabaté Landman

Preconditioners are generally essential for fast convergence in the iterative solution of linear systems of equations. However, the computation of a good preconditioner can be expensive. So, while solving a sequence of many linear systems,…

Numerical Analysis · Mathematics 2020-12-21 Arielle Grim-McNally , Eric de Sturler , Serkan Gugercin

We study a source identification problem for a prototypical elliptic PDE from Dirichlet boundary data. This problem is ill-posed, and the involved forward operator has a significant nullspace. Standard Tikhonov regularization yields…

Optimization and Control · Mathematics 2020-10-29 Ole Løseth Elvetun , Bjørn Fredrik Nielsen

Constrained least squares problems arise in a variety of applications, and many iterative methods are already available to compute their solutions. This paper proposes a new efficient approach to solve nonnegative linear least squares…

Numerical Analysis · Mathematics 2017-01-09 Silvia Gazzola , Yves Wiaux

We propose a novel end-to-end trainable framework for the graph decomposition problem. The minimum cost multicut problem is first converted to an unconstrained binary cubic formulation where cycle consistency constraints are incorporated…

Computer Vision and Pattern Recognition · Computer Science 2018-12-27 Jie Song , Bjoern Andres , Michael Black , Otmar Hilliges , Siyu Tang

In this paper we investigate the use of half-precision Kronecker product singular value decomposition (SVD) approximations as preconditioners for large-scale Tikhonov regularized least squares problems. Half precision reduces storage…

Numerical Analysis · Mathematics 2023-11-28 Yizhou Chen , Xiang Ji , James Nagy

To keep massive MIMO systems cost-efficient, power amplifiers with rather small output dynamic ranges are employed. They may distort the transmit signal and degrade the performance. This paper proposes a distortion aware precoding scheme…

Signal Processing · Electrical Eng. & Systems 2019-05-15 Ali Bereyhi , Saba Asaad , Ralf R. Müller , Symeon Chatzinotas

Randomized neural networks (RaNNs), in which hidden layers remain fixed after random initialization, provide an efficient alternative for parameter optimization compared to fully parameterized networks. In this paper, RaNNs are integrated…

Numerical Analysis · Mathematics 2024-12-30 Yong Shang , Alexander Heinlein , Siddhartha Mishra , Fei Wang

A fruitful approach for solving signal deconvolution problems consists of resorting to a frame-based convex variational formulation. In this context, parallel proximal algorithms and related alternating direction methods of multipliers have…

Other Computer Science · Computer Science 2015-05-28 Nelly Pustelnik , Jean-Christophe Pesquet , Caroline Chaux

In this paper we consider the training of single hidden layer neural networks by pseudoinversion, which, in spite of its popularity, is sometimes affected by numerical instability issues. Regularization is known to be effective in such…

Neural and Evolutionary Computing · Computer Science 2015-08-26 Rossella Cancelliere , Mario Gai , Patrick Gallinari , Luca Rubini

Recursive estimates of large systems of equations in the context of least squares fitting is a common practice in different fields of study. For example, recursive adaptive filtering is extensively used in signal processing and control…

Numerical Analysis · Mathematics 2018-01-04 Nasser Kazemi , Mauricio Sacchi

We study kernel least-squares estimation under a norm constraint. This form of regularisation is known as Ivanov regularisation and it provides better control of the norm of the estimator than the well-established Tikhonov regularisation.…

Statistics Theory · Mathematics 2019-06-17 Stephen Page , Steffen Grünewälder

Employing two distinct types of regularization terms, we propose two regularized extragradient methods for solving equilibrium problems on Hadamard manifolds. The sequences generated by these extragradient algorithms converge to a solution…

Optimization and Control · Mathematics 2026-01-06 Shikher Sharmaa , Pankaj Gautam , Simeon Reich

This work introduces a new cubic regularization method for nonconvex unconstrained multiobjective optimization problems. At each iteration of the method, a model associated with the cubic regularization of each component of the objective…

Optimization and Control · Mathematics 2025-06-11 Douglas S. Gonçalves , Max L. N. Gonçalves , Jefferson G. Melo

For real matrices of full column-rank, we analyze the conditioning of several types of normal equations that are preconditioned by a randomized preconditioner computed in lower precision. These include symmetrically preconditioned normal…

Numerical Analysis · Mathematics 2026-03-18 James E. Garrison , Ilse C. F. Ipsen

Tikhonov regularization is a common technique used when solving poorly behaved optimization problems. Often, and with good reason, this technique is applied by practitioners in an ad hoc fashion. In this note, we systematically illustrate…

Optimization and Control · Mathematics 2022-12-16 J. Adriazola

Discretization of flow in fractured porous media commonly lead to large systems of linear equations that require dedicated solvers. In this work, we develop an efficient linear solver and its practical implementation for mixed-dimensional…

Numerical Analysis · Mathematics 2023-02-08 Xiaozhe Hu , Eirik Keilegavlen , Jan M. Nordbotten

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

The discretization of the double-layer potential integral equation for the interior Dirichlet Laplace problem in a domain with smooth boundary results in a linear system that has a bounded condition number. Thus, the number of iterations…

Numerical Analysis · Mathematics 2014-02-27 Bryan Quaife , George Biros