In this paper, we study the constrained stochastic submodular maximization problem with state-dependent costs. The input of our problem is a set of items whose states (i.e., the marginal contribution and the cost of an item) are drawn from a known probability distribution. The only way to know the realized state of an item is to select that item. We consider two constraints, i.e., \emph{inner} and \emph{outer} constraints. Recall that each item has a state-dependent cost, and the inner constraint states that the total \emph{realized} cost of all selected items must not exceed a give budget. Thus, inner constraint is state-dependent. The outer constraint, one the other hand, is state-independent. It can be represented as a downward-closed family of sets of selected items regardless of their states. Our objective is to maximize the objective function subject to both inner and outer constraints. Under the assumption that larger cost indicates larger "utility", we present a constant approximate solution to this problem.
翻译:在本文中, 我们研究受限的随机子模块最大化问题, 取决于国家的成本。 我们问题的投入是一系列项目, 其状态( 即一个项目的边际贡献和成本) 来自于已知的概率分布。 唯一知道一个项目实现状态的方法是选择该项目。 我们考虑两个制约因素, 即 \ emph{inner} 和\ emph{outer} 限制。 回顾每个项目都有国家依赖的成本, 而内限则指出所有选定项目的总成本不能超过给付预算。 因此, 内限取决于国家。 外部制约, 一方面是状态独立。 它可以代表一个向下封闭的选定项目组群, 不论其状态如何。 我们的目标是在内部和外部制约下最大化目标功能。 在假设成本较大表明更大的“ 用途 ” 的情况下, 我们提出这一问题的常态近似解决办法 。