Stochastic programs where the uncertainty distribution must be inferred from noisy data samples are considered. The stochastic programs are approximated with distributionally-robust optimizations that minimize the worst-case expected cost over ambiguity sets, i.e., sets of distributions that are sufficiently compatible with the observed data. In this paper, the ambiguity sets capture the set of probability distributions whose convolution with the noise distribution remains within a ball centered at the empirical noisy distribution of data samples parameterized by the total variation distance. Using the prescribed ambiguity set, the solutions of the distributionally-robust optimizations converge to the solutions of the original stochastic programs when the numbers of the data samples grow to infinity. Therefore, the proposed distributionally-robust optimization problems are asymptotically consistent. This is proved under the assumption that the distribution of the noise is uniformly diagonally dominant. More importantly, the distributionally-robust optimization problems can be cast as tractable convex optimization problems and are therefore amenable to large-scale stochastic problems.
翻译:本文考虑从噪声数据样本中推断不确定性分布的随机规划问题。将随机规划问题近似为分布式鲁棒优化问题,最小化在包含概率分布集合的曖昧集合中最坏情况下期望代价。本文提出的曖昧集合包含那些与观测到的数据样本的总变差距离为参数的球中的噪声分布卷积之后仍然足够兼容的概率分布。使用所述曖昧集合,当数据样本数逐渐递增时,分布式鲁棒优化问题的解收敛于原始随机规划问题的解。因此,所提出的分布式鲁棒优化问题是渐进一致的。该结论是在噪声分布的分布是均匀对角占优的假设下证明的。更重要的是,分布式鲁棒优化问题可以转化为易于处理的凸优化问题,因此适用于大规模随机问题。