Results 71 to 80 of about 192,768 (193)

Rational maximum likelihood estimators of Kronecker covariance matrices

open access: yesAlgebraic Statistics
As is the case for many curved exponential families, the computation of maximum likelihood estimates in a multivariate normal model with a Kronecker covariance structure is typically carried out with an iterative algorithm, specifically, a block-coordinate ascent algorithm.
Drton, Mathias   +2 more
openaire   +2 more sources

Shrinkage estimation of large covariance matrices: Keep it simple, statistician? [PDF]

open access: yesJournal of Multivariate Analysis, 2019
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Ledoit, Olivier, Wolf, Michael
openaire   +5 more sources

Robust Covariance Estimators Based on Information Divergences and Riemannian Manifold

open access: yesEntropy, 2018
This paper proposes a class of covariance estimators based on information divergences in heterogeneous environments. In particular, the problem of covariance estimation is reformulated on the Riemannian manifold of Hermitian positive-definite (HPD ...
Xiaoqiang Hua   +3 more
doaj   +1 more source

Robust Estimates of Covariance Matrices in the Large Dimensional Regime [PDF]

open access: yesIEEE Transactions on Information Theory, 2014
This article studies the limiting behavior of a class of robust population covariance matrix estimators, originally due to Maronna in 1976, in the regime where both the number of available samples and the population size grow large. Using tools from random matrix theory, we prove that, for sample vectors made of independent entries having some moment ...
Couillet, Romain   +2 more
openaire   +4 more sources

A Novel Approach to 3D-DOA Estimation of Stationary EM Signals Using Convolutional Neural Networks

open access: yesSensors, 2020
This paper proposes a novel three-dimensional direction-of-arrival (3D-DOA) estimation method for electromagnetic (EM) signals using convolutional neural networks (CNN) in a Gaussian or non-Gaussian noise environment.
Dong Chen, Young Hoon Joo
doaj   +1 more source

Group Symmetry and non-Gaussian Covariance Estimation

open access: yes, 2013
We consider robust covariance estimation with group symmetry constraints. Non-Gaussian covariance estimation, e.g., Tyler scatter estimator and Multivariate Generalized Gaussian distribution methods, usually involve non-convex minimization problems ...
Soloveychik, Ilya, Wiesel, Ami
core   +1 more source

Best linear unbiased estimation for varying probability with and without replacement sampling

open access: yesSpecial Matrices, 2019
When sample survey data with complex design (stratification, clustering, unequal selection or inclusion probabilities, and weighting) are used for linear models, estimation of model parameters and their covariance matrices becomes complicated.
Haslett Stephen
doaj   +1 more source

Constrained Covariance Matrices With a Biologically Realistic Structure: Comparison of Methods for Generating High-Dimensional Gaussian Graphical Models

open access: yesFrontiers in Applied Mathematics and Statistics, 2019
High-dimensional data from molecular biology possess an intricate correlation structure that is imposed by the molecular interactions between genes and their products forming various different types of gene networks.
Frank Emmert-Streib   +6 more
doaj   +1 more source

A Noise Covariance Regulated Robust Modified Adaptive Extended Kalman Filter for State of Charge Estimation of Lithium-Ion Battery

open access: yesIEEE Access
A battery management system needs a robust algorithm for online state-of-charge estimation of batteries in different dynamic systems. Due to the ease of implementation, model-based state-of-charge estimation using the extended Kalman filter is popularly ...
Satyaprakash Rout, Satyajit Das
doaj   +1 more source

High-Dimensional Quadratic Discriminant Analysis Under Spiked Covariance Model

open access: yesIEEE Access, 2020
Quadratic discriminant analysis (QDA) is a widely used classification technique that generalizes the linear discriminant analysis (LDA) classifier to the case of distinct covariance matrices among classes.
Houssem Sifaou   +2 more
doaj   +1 more source

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