K-Medoids and K-Center clustering solved to global optimality on up to one billion samples.
Overview
I developed reduced-space spatial branch-and-bound algorithms for K-Medoids and K-Center clustering, with customized lower bounds, bound tightening, and sample reduction, accelerated on hybrid CPU–GPU hardware. They solve problems with up to one billion samples to global optimality, scaling 250× (K-Medoids) and 200,000× (K-Center) beyond earlier exact methods, with over 20% better objectives than widely used heuristics.

Publications
A Global Optimization Algorithm for K-Center Clustering of One Billion Samples
Management Science, 72(6): 5106–5130 (2026).
Global Optimal K-Medoids Clustering of One Million Samples
Advances in Neural Information Processing Systems, 35: 982–994 (2022).
Global Optimization of K-Center Clustering
International Conference on Machine Learning, PMLR 162: 19956–19966 (2022).