@inproceedings{
wang2024outlierrobust,
title={Outlier-Robust Distributionally Robust Optimization via Unbalanced Optimal Transport},
author={Zifan Wang and Yi Shen and Michael M. Zavlanos and Karl Henrik Johansson},
booktitle={The Thirty-eighth Annual Conference on Neural Information Processing Systems},
year={2024},
url={https://openreview.net/forum?id=V8HVsyTSu6}
}
Distributionally Robust Optimization (DRO) accounts for uncertainty in data distributions by optimizing the model performance against the worst possible distribution within an ambiguity set. In this paper, we propose a DRO framework that relies on a new distance inspired by Unbalanced Optimal Transport (UOT). The proposed UOT distance employs a soft penalization term instead of hard constraints, enabling the construction of an ambiguity set that is more resilient to outliers.  Under smoothness conditions, we establish strong duality of the proposed DRO problem. Moreover, we introduce a computationally efficient Lagrangian penalty formulation for which we show that strong duality also holds. Finally, we provide empirical results that demonstrate that our method offers improved robustness to outliers and is computationally less demanding for regression and classification tasks.
Outlier-Robust Distributionally Robust Optimization via Unbalanced Optimal Transport
Zifan Wang Yi Shen Michael M. Zavlanos Karl Henrik Johansson