modaira, 2000;Quiñonero-Candela et al., 2009;Daume III, 2007;Ben-David et al., 2010;Blitzer et al., 2011;Pryzant et al., 2017) or domaininvariant features (Ganin and Lempitsky, 2015;Tzeng et al., 2014).
many DRO problems admit efficient batch optimization procedures based on Lagrangian duality .