activity
20232026
collaborators

6 papers

stat.ME2026

Hybrid principal component analysis in multivariate allometric regression

Koji Tsukuda, Shun Matsuura

In biological data from allometry studies, the largest eigenvalue is typically dominant, and the gaps between minor eigenvalues are often narrow. Such proximity among small minor e…

stat.ME2026

Robust -Estimation of Scatter Matrices via Precision Structure Shrinkage

Soma Nikai, Yuichi Goto, Koji Tsukuda

Maronna's and Tyler's -estimators are among the most widely used robust estimators for scatter matrices. However, when the dimension of observations is relatively high, their pe…

math.ST2026

On spectral clustering under non-isotropic Gaussian mixture models

Kohei Kawamoto, Yuichi Goto, Koji Tsukuda

We evaluate the misclustering probability of a spectral clustering algorithm under a Gaussian mixture model with a general covariance structure. The algorithm partitions the data i…

math.ST2024

Equality between two general ridge estimators and equivalence of their residual sums of squares

Hirai Mukasa, Koji Tsukuda

General ridge estimators are typical linear estimators in a general linear model. The class of them includes some shrinkage estimators in addition to classical linear unbiased esti…

math.ST2024

Estimators for multivariate allometric regression model

Koji Tsukuda, Shun Matsuura

In a regression model with multiple response variables and multiple explanatory variables, if the difference of the mean vectors of the response variables for different values of e…

math.ST2023

Spectral clustering algorithm for the allometric extension model

Kohei Kawamoto, Yuichi Goto, Koji Tsukuda

The spectral clustering algorithm is often used as a binary clustering method for unclassified data by applying the principal component analysis. To study theoretical properties of…