English
Related papers

Related papers: $\ell^1$ penalty for ill-posed inverse problems

200 papers

Sparsification of neural networks is one of the effective complexity reduction methods to improve efficiency and generalizability. We consider the problem of learning a one hidden layer convolutional neural network with ReLU activation…

Optimization and Control · Mathematics 2020-02-26 Thu Dinh , Jack Xin

In the blind deconvolution problem, we observe the convolution of an unknown filter and unknown signal and attempt to reconstruct the filter and signal. The problem seems impossible in general, since there are seemingly many more unknowns…

Information Theory · Computer Science 2021-06-15 Qingyun Sun , David Donoho

We consider the problem of calibrating a compressed sensing measurement system under the assumption that the decalibration consists in unknown gains on each measure. We focus on {\em blind} calibration, using measures performed on a few…

Statistics Theory · Mathematics 2011-12-01 Rémi Gribonval , Gilles Chardon , Laurent Daudet

In compressed sensing, the l0-norm minimization of sparse signal reconstruction is NP-hard. Recent work shows that compared with the best convex relaxation (l1-norm), nonconvex penalties can better approximate the l0-norm and can…

Signal Processing · Electrical Eng. & Systems 2018-05-03 Hao Wang , Zhanglei Shi , Chi-Sing Leung , Hing Cheung So

This paper considers the inverse problem of identifying the source term of parabolic equations from sparse boundary measurements. We used data from moving sensors to locate the unknown source term. This work first proves the uniqueness of…

Analysis of PDEs · Mathematics 2026-04-14 Qiling Gu , Wenlong Zhang , Zhidong Zhang

Inverse Reinforcement Learning (IRL) is the problem of finding a reward function which describes observed/known expert behavior. The IRL setting is remarkably useful for automated control, in situations where the reward function is…

Machine Learning · Computer Science 2022-09-12 Gregory Dexter , Kevin Bello , Jean Honorio

In this paper we analyze the asymptotic properties of l1 penalized maximum likelihood estimation of signals with piece-wise constant mean values and/or variances. The focus is on segmentation of a non-stationary time series with respect to…

Statistics Theory · Mathematics 2014-01-22 Cristian R. Rojas , Bo Wahlberg

We investigate a compressive sensing framework in which the sensors introduce a distortion to the measurements in the form of unknown gains. We focus on blind calibration, using measures performed on multiple unknown (but sparse) signals…

Information Theory · Computer Science 2014-08-26 Cagdas Bilen , Gilles Puy , Rémi Gribonval , Laurent Daudet

We study the problem of recovering a block-sparse signal from under-sampled observations. The non-zero values of such signals appear in few blocks, and their recovery is often accomplished using a $\ell_{1,2}$ optimization problem. In…

Information Theory · Computer Science 2019-07-30 Sajad Daei , Farzan Haddadi , Arash Amini

In the past decade, sparse and low-rank recovery have drawn much attention in many areas such as signal/image processing, statistics, bioinformatics and machine learning. To achieve sparsity and/or low-rankness inducing, the $\ell_1$ norm…

Information Theory · Computer Science 2019-06-07 Fei Wen , Lei Chu , Peilin Liu , Robert C. Qiu

We introduce a general framework to handle structured models (sparse and block-sparse with possibly overlapping blocks). We discuss new methods for their recovery from incomplete observation, corrupted with deterministic and stochastic…

Statistics Theory · Mathematics 2013-02-28 Anatoli Juditsky , Fatma Kılınç Karzan , Arkadi Nemirovski , Boris Polyak

Image reconstruction based on indirect, noisy, or incomplete data remains an important yet challenging task. While methods such as compressive sensing have demonstrated high-resolution image recovery in various settings, there remain issues…

Numerical Analysis · Mathematics 2023-03-07 Jan Glaubitz , Anne Gelb , Guohui Song

We consider an optimization problem with strongly convex objective and linear inequalities constraints. To be able to deal with a large number of constraints we provide a penalty reformulation of the problem. As penalty functions we use a…

Optimization and Control · Mathematics 2020-04-29 Angelia Nedich , Tatiana Tatarenko

We propose a sparse reconstruction framework for solving inverse problems. Opposed to existing sparse regularization techniques that are based on frame representations, we train an encoder-decoder network by including an $\ell^1$-penalty.…

Numerical Analysis · Mathematics 2019-08-07 Daniel Obmann , Johannes Schwab , Markus Haltmeier

This paper presents an error analysis of classical and learned Tikhonov regularization schemes for inverse problems. We first demonstrate, both theoretically and numerically, that using a fixed regularization parameter across varying noise…

Numerical Analysis · Mathematics 2026-04-02 Arne Behrens , Meira Iske , Ming Jiang , Peter Maass , Sebastian Neumayer

We develop techniques to solve ill-posed inverse problems on the sphere by sparse regularisation, exploiting sparsity in both axisymmetric and directional scale-discretised wavelet space. Denoising, inpainting, and deconvolution problems,…

Information Theory · Computer Science 2017-08-17 Christopher G. R. Wallis , Yves Wiaux , Jason D. McEwen

In this paper, we consider the minimization of a Tikhonov functional with an $\ell_1$ penalty for solving linear inverse problems with sparsity constraints. One of the many approaches used to solve this problem uses the Nemskii operator to…

Numerical Analysis · Mathematics 2020-08-26 Fabian Hinterer , Simon Hubmer , Ronny Ramlau

The Laplacian-constrained Gaussian Markov Random Field (LGMRF) is a common multivariate statistical model for learning a weighted sparse dependency graph from given data. This graph learning problem can be formulated as a maximum likelihood…

Machine Learning · Computer Science 2024-04-15 Yakov Medvedovsky , Eran Treister , Tirza Routtenberg

Blind deconvolution is a ubiquitous problem of recovering two unknown signals from their convolution. Unfortunately, this is an ill-posed problem in general. This paper focuses on the {\em short and sparse} blind deconvolution problem,…

Signal Processing · Electrical Eng. & Systems 2019-07-23 Yuqian Zhang , Han-Wen Kuo , John Wright

In this paper we present a linear programming solution for sign pattern recovery of a sparse signal from noisy random projections of the signal. We consider two types of noise models, input noise, where noise enters before the random…

Information Theory · Computer Science 2015-03-13 V. Saligrama , M. Zhao
‹ Prev 1 8 9 10 Next ›