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In space-time adaptive processing (STAP) of the airborne radar system, it is very important to realize sparse restoration of the clutter covariance matrix with a small number of samples. In this paper, a clutter suppression method for…

Signal Processing · Electrical Eng. & Systems 2023-01-30 Tao Zhang , Haifang Zheng , Qijun Luo

We introduce a novel Bayesian approach for both covariate selection and sparse precision matrix estimation in the context of high-dimensional Gaussian graphical models involving multiple responses. Our approach provides a sparse estimation…

Methodology · Statistics 2024-09-25 Anwesha Chakravarti , Naveen N. Narishetty , Feng Liang

Solving large-scale optimization on-the-fly is often a difficult task for real-time computer graphics applications. To tackle this challenge, model reduction is a well-adopted technique. Despite its usefulness, model reduction often…

Graphics · Computer Science 2015-06-30 Jianbo Ye , Zhixin Yan

Covariance tapering is a popular approach for reducing the computational cost of spatial prediction and parameter estimation for Gaussian process models. However, tapering can have poor performance when the process is sampled at spatially…

Computation · Statistics 2016-02-22 David Bolin , Jonas Wallin

This paper deals with adaptive radar detection of a subspace signal competing with two sources of interference. The former is Gaussian with unknown covariance matrix and accounts for the joint presence of clutter plus thermal noise. The…

Applications · Statistics 2016-04-20 Antonio De Maio , Danilo Orlando

Compressive covariance estimation has arisen as a class of techniques whose aim is to obtain second-order statistics of stochastic processes from compressive measurements. Recently, these methods have been used in various image processing…

Image and Video Processing · Electrical Eng. & Systems 2022-07-27 Jonathan Monsalve , Juan Ramirez , Iñaki Esnaola , Henry Arguello

Sparsity in the eigenvectors of signal covariance matrices is exploited in this paper for compression and denoising. Dimensionality reduction (DR) and quantization modules present in many practical compression schemes such as transform…

Applications · Statistics 2015-06-03 Ioannis D. Schizas , Georgios B. Giannakis

In some multivariate problems with missing data, pairs of variables exist that are never observed together. For example, some modern biological tools can produce data of this form. As a result of this structure, the covariance matrix is…

Methodology · Statistics 2013-08-13 Max Grazier G'Sell , Shai S. Shen-Orr , Robert Tibshirani

Many popular statistical models, such as factor and random effects models, give arise a certain type of covariance structures that is a summation of low rank and sparse matrices. This paper introduces a penalized approximation framework to…

Methodology · Statistics 2015-03-19 Xi Luo

This paper addresses the task of estimating a covariance matrix under a patternless sparsity assumption. In contrast to existing approaches based on thresholding or shrinkage penalties, we propose a likelihood-based method that regularizes…

Methodology · Statistics 2021-09-13 Jason Xu , Kenneth Lange

We derive a maximum a posteriori estimator for the linear observation model, where the signal and noise covariance matrices are both uncertain. The uncertainties are treated probabilistically by modeling the covariance matrices with prior…

Statistics Theory · Mathematics 2014-03-12 Dave Zachariah , Nafiseh Shariati , Mats Bengtsson , Magnus Jansson , Saikat Chatterjee

In the Bayesian approach to inverse problems, data are often informative, relative to the prior, only on a low-dimensional subspace of the parameter space. Significant computational savings can be achieved by using this subspace to…

Numerical Analysis · Mathematics 2015-07-07 Alessio Spantini , Antti Solonen , Tiangang Cui , James Martin , Luis Tenorio , Youssef Marzouk

The state-of-the-art methods for estimating high-dimensional covariance matrices all shrink the eigenvalues of the sample covariance matrix towards a data-insensitive shrinkage target. The underlying shrinkage transformation is either…

Machine Learning · Statistics 2025-11-25 Man-Chung Yue , Yves Rychener , Daniel Kuhn , Viet Anh Nguyen

Many statistical applications require an estimate of a covariance matrix and/or its inverse. When the matrix dimension is large compared to the sample size, which happens frequently, the sample covariance matrix is known to perform poorly…

Statistics Theory · Mathematics 2012-07-24 Olivier Ledoit , Michael Wolf

It has been proposed that complex populations, such as those that arise in genomics studies, may exhibit dependencies among observations as well as among variables. This gives rise to the challenging problem of analyzing unreplicated…

Machine Learning · Statistics 2018-06-08 Michael Hornstein , Roger Fan , Kerby Shedden , Shuheng Zhou

One of the major challenges in multivariate analysis is the estimation of population covariance matrix from sample covariance matrix (SCM). Most recent covariance matrix estimators use either shrinkage transformations or asymptotic results…

Methodology · Statistics 2019-12-10 Samruddhi Deshmukh , Amartansh Dubey

This paper is concerned with optimizing the global minimum-variance portfolio's (GMVP) weights in high-dimensional settings where both observation and population dimensions grow at a bounded ratio. Optimizing the GMVP weights is highly…

Signal Processing · Electrical Eng. & Systems 2022-04-13 Maaz Mahadi , Tarig Ballal , Muhammad Moinuddin , Tareq Y. Al-Naffouri , Ubaid Al-Saggaf

Abstract Covariance matrix estimation is a challenging problem in cosmology. Recent work has shown that model covariance matrices can be precise, and that at relatively large scales they can also be accurate. We introduce a data-driven…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-13 Ross O'Connell

Estimation of large sparse covariance matrices is of great importance for statistical analysis, especially in the high-dimensional settings. The traditional approach such as the sample covariance matrix performs poorly due to the high…

Statistics Theory · Mathematics 2023-08-21 Xiaoning Kang , Xinwei Deng

Structured covariance matrix estimation in the presence of missing data is addressed in this paper with emphasis on radar signal processing applications. After a motivation of the study, the array model is specified and the problem of…

Signal Processing · Electrical Eng. & Systems 2022-12-09 Augusto Aubry , Antonio De Maio , Stefano Marano , Massimo Rosamilia