Results 11 to 20 of about 108,134 (338)

Shrinkage estimators of large covariance matrices with Toeplitz targets in array signal processing

open access: yesScientific Reports, 2022
The problem of estimating a large covariance matrix arises in various statistical applications. This paper develops new covariance matrix estimators based on shrinkage regularization.
Bin Zhang, Shoucheng Yuan
doaj   +1 more source

Sparse estimation of a covariance matrix [PDF]

open access: yesBiometrika, 2011
We suggest a method for estimating a covariance matrix on the basis of a sample of vectors drawn from a multivariate normal distribution. In particular, we penalize the likelihood with a lasso penalty on the entries of the covariance matrix. This penalty plays two important roles: it reduces the effective number of parameters, which is important even ...
Jacob Bien, Robert J. Tibshirani
openaire   +3 more sources

HighFrequencyCovariance: A Julia Package for Estimating Covariance Matrices Using High Frequency Financial Data

open access: yesJournal of Statistical Software, 2022
High frequency data typically exhibit asynchronous trading and microstructure noise, which can bias the covariances estimated by standard estimators. While a number of specialized estimators have been proposed, they have had limited availability in open ...
Stuart Baumann, Margaryta Klymak
doaj   +1 more source

A Best Linear Empirical Bayes Method for High-Dimensional Covariance Matrix Estimation

open access: yesSAGE Open, 2023
Covariance matrix estimation plays a significant role in both in the theory and practice of portfolio analysis and risk management. This paper deals with the available data prior to developing a factor model to enhance covariance matrix estimation.
Jin Yuan, Xianghui Yuan
doaj   +1 more source

Sample Space-time Covariance Matrix Estimation [PDF]

open access: yesICASSP 2019 - 2019 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), 2019
Estimation errors are incurred when calculating the sample space-time covariance matrix. We formulate the variance of this estimator when operating on a finite sample set, compare it to known results, and demonstrate its precision in simulations.
Delaosa, Connor   +4 more
openaire   +1 more source

Clutter Covariance Matrix Estimation for Radar Adaptive Detection Based on a Complex-Valued Convolutional Neural Network

open access: yesRemote Sensing, 2023
In this paper, we address the problem of covariance matrix estimation for radar adaptive detection under non-Gaussian clutter. Traditional model-based estimators may suffer from performance loss due to the mismatch between real data and assumed models ...
Naixin Kang   +3 more
doaj   +1 more source

Estimating the covariance matrix: a new approach [PDF]

open access: yesJournal of Multivariate Analysis, 2003
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Tatsuya Kubokawa, M. S. Srivastava
openaire   +2 more sources

Improved Large Dynamic Covariance Matrix Estimation With Graphical Lasso and Its Application in Portfolio Selection

open access: yesIEEE Access, 2020
The estimation of the large and high-dimensional covariance matrix and precision matrix is a fundamental problem in modern multivariate analysis. It has been widely applied in economics, finance, biology, social networks and health sciences. However, the
Xin Yuan   +3 more
doaj   +1 more source

Estimation of the Parameters of Power Function Distribution based on Progressively Type-II Right Censoring with Binomial Removal

open access: yesStatistica, 2023
In this article, we proposed the estimates of unknown parameters of power function distribution in the context of progressive type-II censoring with binomial removals, where the number of units removed at each failure time follows a binomial distribution.
E.I. Abdul Sathar, G.S. Sathyareji
doaj   +1 more source

Improved Shrinkage Estimators of Covariance Matrices With Toeplitz-Structured Targets in Small Sample Scenarios

open access: yesIEEE Access, 2019
Shrinkage regularization is an effective strategy to estimate the covariance matrix of multi-variate random vector in small sample scenarios. The purpose of this paper is to propose improved linear shrinkage estimators of covariance matrix as two types ...
Bin Zhang, Jie Zhou, Jianbo Li
doaj   +1 more source

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