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Related papers: Robust Least Squares for Quantized Data Matrices

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In this paper, we present perturbation analysis and randomized algorithms for the total least squares (TLS) problems. We derive the perturbation bound and check its sharpness by numerical experiments. Motivated by the recently popular…

Numerical Analysis · Mathematics 2014-11-12 Pengpeng Xie , Yimin Wei , Hua Xiang

This paper studies the robustness of reinforcement learning algorithms to errors in the learning process. Specifically, we revisit the benchmark problem of discrete-time linear quadratic regulation (LQR) and study the long-standing open…

Optimization and Control · Mathematics 2021-03-16 Bo Pang , Zhong-Ping Jiang

Adaptive cubic regularization methods for solving nonconvex problems need the efficient computation of the trial step, involving the minimization of a cubic model. We propose a new approach in which this model is minimized in a low…

Optimization and Control · Mathematics 2024-12-02 Stefania Bellavia , Davide Palitta , Margherita Porcelli , Valeria Simoncini

We consider a polynomial reconstruction of smooth functions from their noisy values at discrete nodes on the unit sphere by a variant of the regularized least-squares method of An et al., SIAM J. Numer. Anal. 50 (2012), 1513--1534. As nodes…

Numerical Analysis · Mathematics 2015-01-12 Sergei. V. Pereverzyev , Ian. H. Sloan , Pavlo Tkachenko

We consider the problem of linear fitting of noisy data in the case of broad (say $\alpha$-stable) distributions of random impacts ("noise"), which can lack even the first moment. This situation, common in statistical physics of small…

Data Analysis, Statistics and Probability · Physics 2015-05-27 Eugene B. Postnikov , Igor M. Sokolov

We study the choice of the regularisation parameter for linear ill-posed problems in the presence of data noise and operator perturbations, for which a bound on the operator error is known but the data noise-level is unknown. We introduce a…

Numerical Analysis · Mathematics 2018-07-16 Uno Hämarik , Urve Kangro , Stefan Kindermann , Kemal Raik

As in other estimation scenarios, likelihood based estimation in the normal mixture set-up is highly non-robust against model misspecification and presence of outliers (apart from being an ill-posed optimization problem). A robust…

Methodology · Statistics 2023-12-20 Soumya Chakraborty , Ayanendranath Basu , Abhik Ghosh

Shrinkage estimators of covariance are an important tool in modern applied and theoretical statistics. They play a key role in regularized estimation problems, such as ridge regression (aka Tykhonov regularization), regularized discriminant…

Statistics Theory · Mathematics 2011-05-10 Noureddine El Karoui , Holger Koesters

We have recently presented a method to solve an overdetermined linear system of equations with multiple right hand side vectors, where the unknown matrix is to be symmetric and positive definite. The coefficient and the right hand side…

Optimization and Control · Mathematics 2014-09-19 Negin Bagherpour , Nezam Mahdavi-Amiri

Many regularization schemes for high-dimensional regression have been put forward. Most require the choice of a tuning parameter, using model selection criteria or cross-validation schemes. We show that a simple non-negative or…

Methodology · Statistics 2012-02-07 Nicolai Meinshausen

Many problems in data science can be treated as estimating a low-rank matrix from highly incomplete, sometimes even corrupted, observations. One popular approach is to resort to matrix factorization, where the low-rank matrix factors are…

Machine Learning · Computer Science 2021-04-23 Tian Tong , Cong Ma , Yuejie Chi

Data-driven decision-making is performed by solving a parameterized optimization problem, and the optimal decision is given by an optimal solution for unknown true parameters. We often need a solution that satisfies true constraints even…

Optimization and Control · Mathematics 2020-03-03 Akihiro Yabe , Takanori Maehara

Two new hybrid algorithms are proposed for large-scale linear discrete ill-posed problems in general-form regularization. They are both based on Krylov subspace inner-outer iterative algorithms. At each iteration, they need to solve a…

Numerical Analysis · Mathematics 2024-09-02 Yanfei Yang

The inverse problem associated with electrochemical impedance spectroscopy requiring the solution of a Fredholm integral equation of the first kind is considered. If the underlying physical model is not clearly determined, the inverse…

Numerical Analysis · Mathematics 2022-08-16 Jakob Hansen , Jarom Hogue , Grant Sander , Rosemary Renaut , Sudeep Popat

Robust Optimization has traditionally taken a pessimistic, or worst-case viewpoint of uncertainty which is motivated by a desire to find sets of optimal policies that maintain feasibility under a variety of operating conditions. In this…

Machine Learning · Statistics 2017-11-22 Matthew Norton , Akiko Takeda , Alexander Mafusalov

A common problem in the optimization of structures is the handling of uncertainties in the parameters. If the parameters appear in the constraints, the uncertainties can lead to an infinite number of constraints. Usually the constraints…

Optimization and Control · Mathematics 2012-05-01 Daniel P. Mohr , Ina Stein , Thomas Matzies , Christina A. Knapek

This paper provides a new regularization method which is particularly suitable for linear exponentially ill-posed problems. Under logarithmic source conditions (which have a natural interpretation in terms of Sobolev spaces in the…

Numerical Analysis · Mathematics 2020-07-08 Walter Cedric Simo Tao Lee

In this paper, we develop a regularized higher-order Taylor based method for solving composite (e.g., nonlinear least-squares) problems. At each iteration, we replace each smooth component of the objective function by a higher-order Taylor…

Optimization and Control · Mathematics 2025-03-05 Yassine Nabou , Ion Necoara

Robust quantization improves the tolerance of networks for various implementations, allowing reliable output in different bit-widths or fragmented low-precision arithmetic. In this work, we perform extensive analyses to identify the sources…

Machine Learning · Computer Science 2022-08-02 Sein Park , Yeongsang Jang , Eunhyeok Park

In this work we consider the stable numerical solution of large-scale ill-posed nonlinear least squares problems with nonzero residual. We propose a non-stationary Tikhonov method with inexact step computation, specially designed for…

Optimization and Control · Mathematics 2020-01-03 Stefania Bellavia , Marco Donatelli , Elisa Riccietti