December 22, 2024
Mahmoud Afshari

Mahmoud Afshari

Academic Rank: Associate professor
Address: Mahmoud Afshari, Associate Professor. Department of Statistics, College of science Persian Gulf University, 7516913798, Iran E-mail:afshar.5050@gmail.com or afshar@pgu.ac.ir TEL:00989177125766
Degree: Ph.D in statistics
Phone: 07731223328
Faculty: Faculty of Intelligent Systems and Data Science

Research

Title Bayesian shrinkage wavelet estimation of mean matrix of the matrix variate normal distribution with application in de-noising
Type Article
Keywords
Bayesian shrinkage wavelet Mean matrix Matrix variate normal distribution Stein’s unbiased risk estimate Threshold
Journal COMPUTATIONAL & APPLIED MATHEMATICS
DOI https://doi.org/10.1007/s40314-024-02997-9
Researchers ziba botvandi (First researcher) , Mahmoud Afshari (Second researcher) , Hamid Karamikabir (Third researcher)

Abstract

Suppose that X the random matrix has a matrix variate normal distribution with the mean matrix and covariance matrix , where and are known positive definite covariance matrices. This paper studies the Bayesian shrinkage wavelet estimation of the mean matrix under the balanced loss function. Two soft Bayesian shrinkage wavelet estimators are proposed based on two prior distributions: the matrix variate normal , where is a known positive definite covariance matrix, and the improper prior . Using Bayes estimators as the target estimator and Stein’s unbiased risk estimate technique, the soft Bayesian shrinkage wavelet threshold and the soft generalized Bayesian shrinkage wavelet threshold are obtained. Based on the newly proposed thresholds, we derive the soft Bayesian shrinkage wavelet and the soft generalized Bayesian shrinkage wavelet estimators. The performance of the presented theoretical topics is measured through a simulation study and three real examples. The results show that the soft generalized Bayesian shrinkage wavelet estimator outperforms four classical soft shrinkage wavelet estimators and the soft Bayesian shrinkage wavelet estimator.