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Donghwan Kim

4 papers indexed

arxivcs.CLcs.AIcs.LG2026-07-22

Are Diversity Metrics Measuring Diversity? A Capability-Controlled Audit of Majority-Vote Gain in LLM Ensembles

Donghwan Kim

Majority voting over LLMs is widely assumed to benefit from diversity, and diversity measures are used to choose which models to combine. We ask whether five such measures track diversity or mainly re-express capability, auditing them as predictors of majority-vote gain over the…

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arxivcs.LGmath.OC2026-07-10

Understanding Schedule-Free Methods in Nonconvex Optimization: Rate Guarantees and Escaping Saddles

Jiseok Chae, Donghwan Kim

Schedule-Free methods have attracted growing interest for alleviating the burden of designing and tuning a learning rate scheduler, while matching and sometimes even outperforming optimizers with tuned schedulers. Despite their strong empirical results, their convergence theory i…

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arxivcs.LG2026-06-27

A Kernel Fisher Discriminant Analysis-Based Tree Ensemble Classifier: KFDA Forest

Donghwan Kim, Seung Hwan Park, Jun-Geol Baek

In general, an ensemble classifier is more accurate than a single classifier. In this study, we propose an ensemble classifier called the kernel Fisher discriminant analysis forest (KFDA Forest), which is a tree-based ensemble method that applies KFDA. To promote diversity, boots…

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