English
Related papers

Related papers: Sparse Approximation to the Dirac-{\delta} Distrib…

200 papers

We analyze sparse frame based regularization of inverse problems by means of a diagonal frame decomposition (DFD) for the forward operator, which generalizes the SVD. The DFD allows to define a non-iterative (direct) operator-adapted frame…

Numerical Analysis · Mathematics 2019-12-13 Jürgen Frikel , Markus Haltmeier

The need for fast sparse optimization is emerging, e.g., to deal with large-dimensional data-driven problems and to track time-varying systems. In the framework of linear sparse optimization, the iterative shrinkage-thresholding algorithm…

Optimization and Control · Mathematics 2025-01-22 Vito Cerone , Sophie M. Fosson , Diego Regruto

Orthogonal Matching Pursuit (OMP) plays an important role in data science and its applications such as sparse subspace clustering and image processing. However, the existing OMP-based approaches lack of data adaptiveness so that the data…

Machine Learning · Computer Science 2019-09-02 Jiaqiyu Zhan , Zhiqiang Bai , Yuesheng Zhu

We consider the problem of sampling from the posterior distribution of a $d$-dimensional coefficient vector $\boldsymbol{\theta}$, given linear observations $\boldsymbol{y} = \boldsymbol{X}\boldsymbol{\theta}+\boldsymbol{\varepsilon}$. In…

Methodology · Statistics 2024-07-01 Andrea Montanari , Yuchen Wu

Signal decomposition and multiscale signal analysis provide many useful tools for time-frequency analysis. We proposed a random feature method for analyzing time-series data by constructing a sparse approximation to the spectrogram. The…

Signal Processing · Electrical Eng. & Systems 2023-03-17 Nicholas Richardson , Hayden Schaeffer , Giang Tran

We consider a class of linear integral operators with impulse responses varying regularly in time or space. These operators appear in a large number of applications ranging from signal/image processing to biology. Evaluating their action on…

Numerical Analysis · Mathematics 2016-04-18 Paul Escande , Pierre Weiss

We present a novel approach to the formulation and the resolution of sparse Linear Discriminant Analysis (LDA). Our proposal, is based on penalized Optimal Scoring. It has an exact equivalence with penalized LDA, contrary to the multi-class…

Machine Learning · Computer Science 2012-07-03 Luis Francisco Sanchez Merchante , Yves Grandvalet , Gerrad Govaert

The sparse regression problem, also known as best subset selection problem, can be cast as follows: Given a set $S$ of $n$ points in $\mathbb{R}^d$, a point $y\in \mathbb{R}^d$, and an integer $2 \leq k \leq d$, find an affine combination…

Data Structures and Algorithms · Computer Science 2020-01-01 Jean Cardinal , Aurélien Ooms

Sparse principal component analysis (PCA) improves interpretability of the classic PCA by introducing sparsity into the dimension-reduction process. Optimization models for sparse PCA, however, are generally non-convex, non-smooth and more…

Optimization and Control · Mathematics 2024-01-09 Lei Wang , Xin Liu , Yin Zhang

In this paper modified variants of the sparse Fourier transform algorithms from [14] are presented which improve on the approximation error bounds of the original algorithms. In addition, simple methods for extending the improved sparse…

Numerical Analysis · Mathematics 2010-10-04 M. A. Iwen

Uncertainty estimation is crucial in safety-critical applications, where robust out-of-distribution (OOD) detection is essential. Traditional Bayesian methods, though effective, are often hindered by high computational demands. As an…

Machine Learning · Computer Science 2024-11-06 Maksim Zhdanov , Stanislav Dereka , Sergey Kolesnikov

Various precoders have been recently studied by the wireless community to combat the channel fading effects. Two prominent precoders are implemented with the discrete Fourier transform (DFT) and Walsh-Hadamard transform (WHT). The WHT…

Information Theory · Computer Science 2023-09-11 Roberto Bomfin , Marwa Chafii

Despite the remarkable progress, weakly supervised segmentation approaches are still inferior to their fully supervised counterparts. We obverse the performance gap mainly comes from their limitation on learning to produce high-quality…

Computer Vision and Pattern Recognition · Computer Science 2018-05-29 Yunchao Wei , Huaxin Xiao , Honghui Shi , Zequn Jie , Jiashi Feng , Thomas S. Huang

Ultra-reliable wireless communication links require the utilization of all diversity sources of a wireless communication channel. Hadani et al. propose a two dimensional discrete symplectic Fourier transform (DSFT) as orthogonal pre-coder…

Information Theory · Computer Science 2019-07-24 Thomas Zemen , Markus Hofer , David Loeschenbrand , Christoph Pacher

Direction of arrival (DOA) estimation is a classical problem in signal processing with many practical applications. Its research has recently been advanced owing to the development of methods based on sparse signal reconstruction. While…

Applications · Statistics 2016-11-18 Zai Yang , Lihua Xie , Cishen Zhang

Sparse representation of astronomical images is discussed. It is shown that a significant gain in sparsity is achieved when particular mixed dictionaries are used for approximating these types of images with greedy selection strategies.…

Mathematical Physics · Physics 2015-06-11 Laura Rebollo-Neira , James Bowley

We describe a fast approximation algorithm for the $\Delta$-separated sparsity projection problem. The $\Delta$-separated sparsity model was introduced by Hegde, Duarte and Cevher (2009) to capture the firing process of a single Poisson…

Data Structures and Algorithms · Computer Science 2017-12-20 Henning Bruhn , Oliver Schaudt

We propose a method for finding a cumulative distribution function (cdf) that minimizes the distance to a given cdf, while belonging to an ambiguity set constructed relative to another cdf and, possibly, incorporating soft information. Our…

Optimization and Control · Mathematics 2024-08-23 Julio Deride , Johannes O. Royset , Fernanda Urrea

We recently proposed a general algorithm for approximating nonstandard Bayesian posterior distributions by minimization of their Kullback-Leibler divergence with respect to a more convenient approximating distribution. In this note we offer…

Computation · Statistics 2014-01-10 Tim Salimans

In this paper, a new method is proposed for sparse PCA based on the recursive divide-and-conquer methodology. The main idea is to separate the original sparse PCA problem into a series of much simpler sub-problems, each having a closed-form…

Computer Vision and Pattern Recognition · Computer Science 2012-12-03 Qian Zhao , Deyu Meng , Zongben Xu