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Related papers: A Lifted $\ell_1 $ Framework for Sparse Recovery

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We consider a regularization problem whose objective function consists of a convex fidelity term and a regularization term determined by the $\ell_1$ norm composed with a linear transform. Empirical results show that the regularization with…

Numerical Analysis · Mathematics 2023-01-18 Qianru Liu , Rui Wang , Yuesheng Xu , Mingsong Yan

We consider the problem of recovering polynomials that are sparse with respect to the basis of Legendre polynomials from a small number of random samples. In particular, we show that a Legendre s-sparse polynomial of maximal degree N can be…

Numerical Analysis · Mathematics 2011-04-05 Holger Rauhut , Rachel Ward

We propose a unified framework to solve general low-rank plus sparse matrix recovery problems based on matrix factorization, which covers a broad family of objective functions satisfying the restricted strong convexity and smoothness…

Machine Learning · Statistics 2018-02-21 Xiao Zhang , Lingxiao Wang , Quanquan Gu

In inverse problems, the use of an $\ell_{12}$ analysis regularizer induces a bias in the estimated solution. We propose a general refitting framework for removing this artifact while keeping information of interest contained in the biased…

Optimization and Control · Mathematics 2019-03-06 Charles-Alban Deledalle , Nicolas Papadakis , Joseph Salmon , Samuel Vaiter

In this paper, we consider the efficient and robust reconstruction of signals and images via $\ell_{1}-\alpha \ell_{2}~(0<\alpha\leq 1)$ minimization in impulsive noise case. To achieve this goal, we introduce two new models: the…

Optimization and Control · Mathematics 2018-10-15 Peng Li , Huanmin Ge , Wengu Chen

Deep neural networks (DNNs) have achieved extraordinary success in numerous areas. However, to attain this success, DNNs often carry a large number of weight parameters, leading to heavy costs of memory and computation resources.…

Computer Vision and Pattern Recognition · Computer Science 2019-01-07 Rongrong Ma , Jianyu Miao , Lingfeng Niu , Peng Zhang

We consider a minimization problem whose objective function is the sum of a fidelity term, not necessarily convex, and a regularization term defined by a positive regularization parameter $\lambda$ multiple of the $\ell_0$ norm composed…

Optimization and Control · Mathematics 2021-11-17 Yuesheng Xu

In $\ell^1$-regularization, which is an important tool in signal and image processing, one usually is concerned with signals and images having a sparse representation in some suitable basis, e.g. in a wavelet basis. Many results on…

Optimization and Control · Mathematics 2018-09-28 Jens Flemming , Bernd Hofmann , Ivan Veselic

Consider reconstructing a signal $x$ by minimizing a weighted sum of a convex differentiable negative log-likelihood (NLL) (data-fidelity) term and a convex regularization term that imposes a convex-set constraint on $x$ and enforces its…

Computation · Statistics 2017-02-28 Renliang Gu , Aleksandar Dogandžić

Designing computational experiments involving $\ell_1$ minimization with linear constraints in a finite-dimensional, real-valued space for receiving a sparse solution with a precise number $k$ of nonzero entries is, in general, difficult.…

Optimization and Control · Mathematics 2013-09-11 Christian Kruschel , Dirk A. Lorenz

Sparse estimation methods are aimed at using or obtaining parsimonious representations of data or models. While naturally cast as a combinatorial optimization problem, variable or feature selection admits a convex relaxation through the…

Machine Learning · Computer Science 2012-04-23 Francis Bach , Rodolphe Jenatton , Julien Mairal , Guillaume Obozinski

Extreme learning machine (ELM) is a network model that arbitrarily initializes the first hidden layer and can be computed speedily. In order to improve the classification performance of ELM, a $\ell_2$ and $\ell_{0.5}$ regularization ELM…

Optimization and Control · Mathematics 2023-01-05 Liangjuan Zhou , Wei Miao

The $\ell_1$-penalized method, or the Lasso, has emerged as an important tool for the analysis of large data sets. Many important results have been obtained for the Lasso in linear regression which have led to a deeper understanding of…

Machine Learning · Statistics 2011-12-30 Jian Huang , Cun-Hui Zhang

In recent studies on sparse modeling, the nonconvex regularization approaches (particularly, $L_{q}$ regularization with $q\in(0,1)$) have been demonstrated to possess capability of gaining much benefit in sparsity-inducing and efficiency.…

Numerical Analysis · Computer Science 2015-06-17 Jinshan Zeng , Shaobo Lin , Yao Wang , Zongben Xu

We discuss a general notion of "sparsity structure" and associated recoveries of a sparse signal from its linear image of reduced dimension possibly corrupted with noise. Our approach allows for unified treatment of (a) the "usual sparsity"…

Optimization and Control · Mathematics 2016-11-26 Anatoli Juditsky , Fatma Kilinc Karzan , Arkadi Nemirovski

Sparse recovery is ubiquitous in machine learning and signal processing. Due to the NP-hard nature of sparse recovery, existing methods are known to suffer either from restrictive (or even unknown) applicability conditions, or high…

Signal Processing · Electrical Eng. & Systems 2024-03-21 William de Vazelhes , Bhaskar Mukhoty , Xiao-Tong Yuan , Bin Gu

Learned sparse retrieval (LSR) is a family of first-stage retrieval methods that are trained to generate sparse lexical representations of queries and documents for use with an inverted index. Many LSR methods have been recently introduced,…

Information Retrieval · Computer Science 2023-03-28 Thong Nguyen , Sean MacAvaney , Andrew Yates

This paper is intended to solve the nonconvex $\ell_{p}$-ball constrained nonlinear optimization problems. An iteratively reweighted method is proposed, which solves a sequence of weighted $\ell_{1}$-ball projection subproblems. At each…

Optimization and Control · Mathematics 2024-10-28 Hao Wang , Xiangyu Yang , Wei Jiang

In this paper, we study the support recovery guarantees of underdetermined sparse regression using the $\ell_1$-norm as a regularizer and a non-smooth loss function for data fidelity. More precisely, we focus in detail on the cases of…

Information Theory · Computer Science 2016-11-04 Kévin Degraux , Gabriel Peyré , Jalal M. Fadili , Laurent Jacques

We consider a new family of regularizers, termed {\it weighted sorted $\ell_1$ norms} (WSL1), which generalizes the recently introduced {\it octagonal shrinkage and clustering algorithm for regression} (OSCAR) and also contains the $\ell_1$…

Computer Vision and Pattern Recognition · Computer Science 2014-04-14 Xiangrong Zeng , Mário A. T. Figueiredo