Sparsity Constrained Inverse Problems


Download Sparsity Constrained Inverse Problems PDF/ePub or read online books in Mobi eBooks. Click Download or Read Online button to get Sparsity Constrained Inverse Problems book now. This website allows unlimited access to, at the time of writing, more than 1.5 million titles, including hundreds of thousands of titles in various foreign languages.

Download

Inverse Problems with Sparsity Constraints


Inverse Problems with Sparsity Constraints

Author: Dennis Trede

language: en

Publisher: Logos Verlag Berlin GmbH

Release Date: 2010


DOWNLOAD





This thesis contributes to the field of inverse problems with sparsity constraints. Since the pioneering work by Daubechies, Defries and De Mol in 2004, methods for solving operator equations with sparsity constraints play a central role in the field of inverse problems. This can be explained by the fact that the solutions of many inverse problems have a sparse structure, in other words, they can be represented using only finitely many elements of a suitable basis or dictionary. Generally, to stably solve an ill-posed inverse problem one needs additional assumptions on the unknown solution--the so-called source condition. In this thesis, the sparseness stands for the source condition, and with that in mind, stability results for two different approximation methods are deduced, namely, results for the Tikhonov regularization with a sparsity-enforcing penalty and for the orthogonal matching pursuit. The practical relevance of the theoretical results is shown with two examples of convolution type, namely, an example from mass spectrometry and an example from digital holography of particles.

Theoretical Foundations and Numerical Methods for Sparse Recovery


Theoretical Foundations and Numerical Methods for Sparse Recovery

Author: Massimo Fornasier

language: en

Publisher: Walter de Gruyter

Release Date: 2010-07-30


DOWNLOAD





The present collection is the very first contribution of this type in the field of sparse recovery. Compressed sensing is one of the important facets of the broader concept presented in the book, which by now has made connections with other branches such as mathematical imaging, inverse problems, numerical analysis and simulation. The book consists of four lecture notes of courses given at the Summer School on "Theoretical Foundations and Numerical Methods for Sparse Recovery" held at the Johann Radon Institute for Computational and Applied Mathematics in Linz, Austria, in September 2009. This unique collection will be of value for a broad community and may serve as a textbook for graduate courses. From the contents: "Compressive Sensing and Structured Random Matrices" by Holger Rauhut "Numerical Methods for Sparse Recovery" by Massimo Fornasier "Sparse Recovery in Inverse Problems" by Ronny Ramlau and Gerd Teschke "An Introduction to Total Variation for Image Analysis" by Antonin Chambolle, Vicent Caselles, Daniel Cremers, Matteo Novaga and Thomas Pock

Algorithms for Sparsity-Constrained Optimization


Algorithms for Sparsity-Constrained Optimization

Author: Sohail Bahmani

language: en

Publisher: Springer Science & Business Media

Release Date: 2013-10-07


DOWNLOAD





This thesis demonstrates techniques that provide faster and more accurate solutions to a variety of problems in machine learning and signal processing. The author proposes a "greedy" algorithm, deriving sparse solutions with guarantees of optimality. The use of this algorithm removes many of the inaccuracies that occurred with the use of previous models.