English
Related papers

Related papers: A symmetric alternating minimization algorithm for…

200 papers

Consider solving large sparse range symmetric singular linear systems $ A {\bf x}= {\bf b} $ which arise, for instance, in the discretization of convection diffusion equations with periodic boundary conditions, and partial differential…

Numerical Analysis · Mathematics 2022-11-02 Kota Sugihara , Ken Hayami , Liao Zeyu

Stochastic variance reduced gradient (SVRG) is a popular variance reduction technique for accelerating stochastic gradient descent (SGD). We provide a first analysis of the method for solving a class of linear inverse problems in the lens…

Numerical Analysis · Mathematics 2022-01-19 Bangti Jin , Zehui Zhou , Jun Zou

We study optimization algorithms based on variance reduction for stochastic gradient descent (SGD). Remarkable recent progress has been made in this direction through development of algorithms like SAG, SVRG, SAGA. These algorithms have…

Machine Learning · Computer Science 2016-01-26 Sashank J. Reddi , Ahmed Hefny , Suvrit Sra , Barnabás Póczos , Alex Smola

We propose a new asynchronous parallel block-descent algorithmic framework for the minimization of the sum of a smooth nonconvex function and a nonsmooth convex one, subject to both convex and nonconvex constraints. The proposed framework…

Optimization and Control · Mathematics 2018-04-02 Loris Cannelli , Francisco Facchinei , Vyacheslav Kungurtsev , Gesualdo Scutari

The training of deep neural networks is inherently a nonconvex optimization problem, yet standard approaches such as stochastic gradient descent (SGD) require simultaneous updates to all parameters, often leading to unstable convergence and…

Machine Learning · Computer Science 2025-08-07 Chengcheng Yan , Jiawei Xu , Zheng Peng , Qingsong Wang

Neural network approaches have been demonstrated to work quite well to solve partial differential equations in practice. In this context approaches like physics-informed neural networks and the Deep Ritz method have become popular. In this…

Numerical Analysis · Mathematics 2025-09-12 Andreas Langer , Sara Behnamian

In this paper, we consider the sparse least squares regression problem with probabilistic simplex constraint. Due to the probabilistic simplex constraint, one could not apply the L1 regularization to the considered regression model. To find…

Optimization and Control · Mathematics 2021-12-28 Guiyun Xiao , Zheng-Jian Bai

Due to the COVID-19 pandemic, there is an increasing demand for portable CT machines worldwide in order to diagnose patients in a variety of settings. This has led to a need for CT image reconstruction algorithms that can produce high…

Numerical Analysis · Mathematics 2025-12-10 Mai Phuong Pham Huynh , Manuel Santana , Ana Castillo

Total variation (TV) is a widely used function for regularizing imaging inverse problems that is particularly appropriate for images whose underlying structure is piecewise constant. TV regularized optimization problems are typically solved…

Image and Video Processing · Electrical Eng. & Systems 2025-08-26 Edward P. Chandler , Shirin Shoushtari , Brendt Wohlberg , Ulugbek S. Kamilov

The phase retrieval problem is a fundamental problem in many fields, which is appealing for investigation. It is to recover the signal vector $\tilde{x}\in\mathbb{C}^d$ from a set of $N$ measurements $b_n=|f^*_n\tilde{x}|^2,\ n=1,\cdots,…

Optimization and Control · Mathematics 2017-08-30 Jian-Feng Cai , Haixia Liu , Yang Wang

The main goal of this paper is to propose a new quaternion total variation regularization model for solving linear ill-posed quaternion inverse problems, which arise from three-dimensional signal filtering or color image processing. The…

Numerical Analysis · Mathematics 2024-08-07 Xuan Liu , Zhigang Jia , Xiaoqing Jin

Regularization approaches have demonstrated their effectiveness for solving ill-posed problems. However, in the context of variational restoration methods, a challenging question remains, which is how to find a good regularizer. While total…

Optimization and Control · Mathematics 2011-10-25 Nelly Pustelnik , Caroline Chaux , Jean-Christophe Pesquet

We consider least squares semidefinite programming (LSSDP) where the primal matrix variable must satisfy given linear equality and inequality constraints, and must also lie in the intersection of the cone of symmetric positive semidefinite…

Optimization and Control · Mathematics 2015-05-26 Defeng Sun , Kim-Chuan Toh , Liuqin Yang

In this paper, we study a class of bilevel optimization problems where the lower-level problem is a convex composite optimization model, which arises in various applications, including bilevel hyperparameter selection for regularized…

Optimization and Control · Mathematics 2026-05-13 Xiaoning Bai , Shangzhi Zeng , Jin Zhang , Lezhi Zhang

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

This letter addresses the problem of estimating block sparse signal with unknown group partitions in a multiple measurement vector (MMV) setup. We propose a Bayesian framework by applying an adaptive total variation (TV) penalty on the…

Signal Processing · Electrical Eng. & Systems 2025-03-13 Hamza Djelouat , Reijo Leinonen , Mikko J. Sillanpää , Bhaskar D. Rao , Markku Juntti

We present a new vectorial total variation method that addresses the problem of color consistent image filtering. Our approach is inspired from the double-opponent cell representation in the human visual cortex. Existing methods of…

Computer Vision and Pattern Recognition · Computer Science 2016-05-20 Freddie Åström , Christoph Schnörr

The Alternating Direction Method of Multipliers (ADMM) has been proved to be effective for solving separable convex optimization subject to linear constraints. In this paper, we propose a Generalized Symmetric ADMM (GS-ADMM), which updates…

Optimization and Control · Mathematics 2018-12-11 Jianchao Bai , Jicheng Li , Fengmin Xu , Hongchao Zhang

This paper considers the constrained total variation (TV) denoising problem for complex-valued images. We extend the definition of TV seminorms for real-valued images to dealing with complex-valued ones. In particular, we introduce two…

Image and Video Processing · Electrical Eng. & Systems 2021-09-14 Yunhui Gao , Liangcai Cao

Total variation (TV) regularization has proven effective for a range of computer vision tasks through its preferential weighting of sharp image edges. Existing TV-based methods, however, often suffer from the over-smoothing issue and…

Computer Vision and Pattern Recognition · Computer Science 2018-12-26 Dong Gong , Mingkui Tan , Qinfeng Shi , Anton van den Hengel , Yanning Zhang