Test of independence in a 2×2 contingency table with nonignorable nonresponse via constrained EM algorithm. - Keiji Takai; Yutaka Kano (Comput. Stat. Data Anal., 2008)

Simple Computation of Maximum Likelihood Estimates in Latent Class Model with Equality and Constant Constraints. - Keiji Takai; Yutaka Kano (Commun. Stat. Simul. Comput., 2009)

Relation between Stay-Time and Purchase Probability Based on RFID Data in a Japanese Supermarket. - Keiji Takai; Katsutoshi Yada (KES (3), 2010)

Clockwise and Anti-clockwise Directions of Customer Orientation in a Supermarket: Evidence from RFID Data. - Marina Kholod; Keiji Takai; Katsutoshi Yada (KES (3), 2011)

Finding latent groups of customers via the poisson mixture regression model. - Keiji Takai; Katsutoshi Yada (SMC, 2011)

Analysis of NMAR missing data without specifying missing-data mechanisms in a linear latent variate model. - Yutaka Kano; Keiji Takai (J. Multivar. Anal., 2011)

Exploration of Dependencies among Sections in a Supermarket Using a Tree-Structured Undirected Graphical Model. - Keiji Takai (ICDM Workshops, 2012)

Constrained EM algorithm with projection method. - Keiji Takai (Comput. Stat., 2012)

A framework for analysis of the effect of time on shopping behavior. - Keiji Takai; Katsutoshi Yada (J. Intell. Inf. Syst., 2013)

Global Distribution of Watches: A Network Analysis of Trade Relations. - Pierre-Yves Donze; Ken Ishibashi; Bo Wu; Yuta Kaneko; Kei Miyazaki; Keiji Takai (ICDM Workshops, 2017)

Finite-sample analysis of impacts of unlabeled data and their labeling mechanisms in linear discriminant analysis. - Kenichi Hayashi; Keiji Takai (Commun. Stat. Simul. Comput., 2017)

Incomplete-data Fisher scoring method with steplength adjustment. - Keiji Takai (Stat. Comput., 2020)