December 22, 2024
Hamid Karamikabir

Hamid Karamikabir

Academic Rank: Assistant professor
Address: Department of Statistics, Persian Gulf University, Bushehr, Iran.
Degree: Ph.D in Statistics
Phone: 09188175368
Faculty: Faculty of Intelligent Systems and Data Science

Research

Title Soft thresholding wavelet shrinkage estimation for mean matrix of matrix-variate normal distribution: low and high dimensional
Type Article
Keywords
Balanced loss function · Matrix-variate normal distribution · Restricted parameter · Soft wavelet estimator · Stein’s unbiased risk estimate · Threshold
Journal SOFT COMPUTING
DOI https://doi.org/10.1007/s00500-022-07005-y
Researchers Hamid Karamikabir (First researcher) , Ahmad Navid Asghari (Second researcher) , AbdolAziz Salimi (Third researcher)

Abstract

One of the most important issues in matrix-variate normal distribution is the mean matrix parameter estimation problem. In this paper, we introduce a new soft-threshold wavelet shrinkage estimator based on Stein’s unbiased risk estimate (SURE) for the matrix-variate normal distribution.We focus on particular thresholding rules to obtain a new SURE threshold and we produce new estimators under balanced loss function. In addition, we obtain the restricted soft-threshold wavelet shrinkage estimator based on non-negative sub matrix of the mean matrix. Also, we obtain the soft-threshold wavelet shrinkage estimator in high dimensional cases. Denoising real data set is one of the challenges in this field. In this regard, we present a simulation study to test the validity of proposed estimator and provide real examples in low and high-dimensional case. After denoising the real data sets, by computing average mean square error, we find that the new estimator dominates other competing estimators.