Date of Award

2026-05-01

Degree Name

Doctor of Philosophy

Department

Data Science

Advisor(s)

Xiaogang Su

Abstract

High-dimensional logistic regression is particularly vulnerable to outliers, which can distort estimation, weaken variable selection, and harm prediction accuracy. This dissertation introduces RobENetLog, a robust elastic net logistic regression method that jointly selects informative variables and reliable observations by extending ideas from least trimmed squares regression to the classification setting. The proposed approach combines adaptive outlier detection with trimmed penalized estimation so that it can address contamination in both predictors and responses across a wide range of dimensional settings. Simulation studies show that RobENetLog consistently improves predictive performance and robustness in the presence of outliers, while remaining competitive with standard methods on clean data. The method also adapts automatically to different data structures, placing emphasis on the most informative type of outlier detection for the setting at hand. In addition, applications to three real-world datasets from chemometrics, genomics, and biomedical voice analysis demonstrate its practical value in challenging classification problems involving high dimensionality, correlated predictors, and suspected outliers. Across these studies, the method provides accurate classification, stable feature selection, and meaningful identification of atypical observations. An accompanying R package will make the approach readily available for practical applications.

Language

en

Provenance

Received from ProQuest

File Size

207 p.

File Format

application/pdf

Rights Holder

Chitra Bahadur Karki

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