activity
20242026
collaborators

6 papers

stat.ME2026

Zero-inflated stochastic volatility model for disaggregated inflation data with exact zeros

Geonhee Han, Kaoru Irie

The disaggregated time-series for the Consumer Price Index (CPI) often exhibits exact zero price changes, stemming from structural features of the data collection process. However,…

stat.ME2025

On non-stationarity of the Poisson gamma state space models

Kaoru Irie, Tevfik Aktekin

The Poisson-gamma state space (PGSS) models have been utilized in the analysis of non-negative integer-valued time series to sequentially obtain closed form filtering and predictiv…

stat.ME2025

The Group R2D2 Shrinkage Prior for Sparse Linear Models with Grouped Covariates

Eric Yanchenko, Kaoru Irie, Shonosuke Sugasawa

Shrinkage priors are a popular Bayesian paradigm to handle sparsity in high-dimensional regression. Still limited, however, is a flexible class of shrinkage priors to handle groupe…

stat.ME2025

Outlier-Robust Bayesian Multivariate Analysis with Correlation-Intact Sandwich Mixture

Yasuyuki Hamura, Kaoru Irie, Shonosuke Sugasawa

Handling outliers is a fundamental challenge in multivariate data analysis because outliers may distort the structures of correlation or conditional independence. Although robust B…

stat.AP2024

State-Space Modeling of Shape-constrained Functional Time Series

Daichi Hiraki, Yasuyuki Hamura, Kaoru Irie +1

Functional time series data frequently appears in econometric analyses, where the functions of interest are subject to some shape constraints, including monotonicity and convexity,…

math.NA2024

Quantifying uncertainty in the numerical integration of evolution equations based on Bayesian isotonic regression

Yuto Miyatake, Kaoru Irie, Takeru Matsuda

This paper presents a new Bayesian framework for quantifying discretization errors in numerical solutions of ordinary differential equations. By modelling the errors as random vari…