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Selecting regularization parameters in penalized high-dimensional graphical models in a principled, data-driven, and computationally efficient manner continues to be one of the key challenges in high-dimensional statistics. We present…

Methodology · Statistics 2016-10-19 Christian L. Müller , Richard Bonneau , Zachary Kurtz

A critical task in graph signal processing is to estimate the true signal from noisy observations over a subset of nodes, also known as the reconstruction problem. In this paper, we propose a node-adaptive regularization for graph signal…

Signal Processing · Electrical Eng. & Systems 2021-02-08 Maosheng Yang , Mario Coutino , Geert Leus , Elvin Isufi

Parametric model order reduction using reduced basis methods can be an effective tool for obtaining quickly solvable reduced order models of parametrized partial differential equation problems. With speedups that can reach several orders of…

Numerical Analysis · Mathematics 2022-01-26 Mario Ohlberger , Stephan Rave

Inverse problems are inherently ill-posed and therefore require regularization techniques to achieve a stable solution. While traditional variational methods have well-established theoretical foundations, recent advances in machine learning…

Numerical Analysis · Mathematics 2023-09-15 Simon Göppel , Jürgen Frikel , Markus Haltmeier

Robustness and stability of image-reconstruction algorithms have recently come under scrutiny. Their importance to medical imaging cannot be overstated. We review the known results for the topical variational regularization strategies…

Optimization and Control · Mathematics 2023-01-24 Pol del Aguila Pla , Sebastian Neumayer , Michael Unser

This paper deals with the resolution of inverse problems in a periodic setting or, in other terms, the reconstruction of periodic continuous-domain signals from their noisy measurements. We focus on two reconstruction paradigms: variational…

Optimization and Control · Mathematics 2018-11-14 Anaïs Badoual , Julien Fageot , Michael Unser

Piecewise constant denoising can be solved either by deterministic optimization approaches, based on the Potts model, or by stochastic Bayesian procedures. The former lead to low computational time but require the selection of a…

Machine Learning · Computer Science 2017-10-11 Jordan Frecon , Nelly Pustelnik , Nicolas Dobigeon , Herwig Wendt , Patrice Abry

In this paper we study Tikhonov regularization for the stable solution of an ill-posed non-linear operator equation. The operator we consider, which is related to an active contour model for image segmentation, is continuous, compact, but…

Numerical Analysis · Mathematics 2012-09-12 Markus Grasmair

Tilt stability is a fundamental concept of variational analysis and optimization that plays a pivotal role in both theoretical issues and numerical computations. This paper investigates tilt stability of local minimizers for a general class…

Optimization and Control · Mathematics 2025-07-16 Boris S. Mordukhovich , Peipei Tang , Chengjing Wang

Motion detection has been widely used in many applications, such as surveillance and robotics. Due to the presence of the static background, a motion video can be decomposed into a low-rank background and a sparse foreground. Many…

Computer Vision and Pattern Recognition · Computer Science 2023-04-12 Jing Qin , Biyun Xie

Regularization methods allow one to handle a variety of inferential problems where there are more covariates than cases. This allows one to consider a potentially enormous number of covariates for a problem. We exploit the power of these…

Methodology · Statistics 2012-10-03 Yoonkyung Lee , Steven N. MacEachern , Yoonsuh Jung

We consider hierarchical variational inequality problems, or more generally, variational inequalities defined over the set of zeros of a monotone operator. This framework includes convex optimization over equilibrium constraints and…

Optimization and Control · Mathematics 2026-01-07 Daniel Cortild , Meggie Marschner , Mathias Staudigl

Non-uniqueness and instability are characteristic features of image reconstruction processes. As a result, it is necessary to develop regularization methods that can be used to compute reliable approximate solutions. A regularization method…

Numerical Analysis · Mathematics 2022-12-16 Andrea Ebner , Markus Haltmeier

Several strategies for nonlinearity mitigation based on signal processing at the transmitter and/or receiver side are analyzed and their effectiveness is discussed. Improved capacity lower bounds based on their combination are presented.

Information Theory · Computer Science 2021-07-15 Marco Secondini , Stella Civelli , Enrico Forestieri

The method of regularised stokeslets is widely used in microscale biological fluid dynamics due to its ease of implementation, natural treatment of complex moving geometries, and removal of singular functions to integrate. The standard…

Numerical Analysis · Mathematics 2021-03-10 Meurig Gallagher , David Smith

The importance of regularization has been well established in image reconstruction -- which is the computational inversion of imaging forward model -- with applications including deconvolution for microscopy, tomographic reconstruction,…

Image and Video Processing · Electrical Eng. & Systems 2021-06-29 Sanjay Viswanath , Manu Ghulyani , Muthuvel Arigovindan

In this paper we present a tractable approach for regularizing randomly placed points, by splitting them into two subsets: the first is generated by means of the Mat\'ern hard-core point process, while the remaining points constitute the…

Statistics Theory · Mathematics 2016-05-27 Akram Al-Hourani , Bill Moran , Sithamparanathan Kandeepan

This article addresses the challenge of learning effective regularizers for linear inverse problems. We analyze and compare several types of learned variational regularization against the theoretical benchmark of the optimal affine…

Numerical Analysis · Mathematics 2025-10-15 Sebastian Banert , Christoph Brauer , Dirk Lorenz , Lionel Tondji

In recent years, a variety of learned regularization frameworks for solving inverse problems in imaging have emerged. These offer flexible modeling together with mathematical insights. The proposed methods differ in their architectural…

This paper addresses the problem of synchronizing orthogonal matrices over directed graphs. For synchronized transformations (or matrices), composite transformations over loops equal the identity. We formulate the synchronization problem as…

Optimization and Control · Mathematics 2017-04-10 Johan Thunberg , Florian Bernard , Jorge Goncalves