š¤ AI Summary
This work addresses the challenge of balancing submodular utility maximization against cost minimization in applications such as recommender systems and influence maximization, where traditional approaches yield only a single solution and fail to capture the rich trade-offs between these objectives. The paper formally introduces the Pareto-āØf,cā© problem and proposes the notion of an (αā,αā)-approximate Pareto front. It further develops efficient algorithms that provably approximate the Pareto set for diverse combinations of submodular utility and cost functions. Extensive experiments on multiple real-world datasets demonstrate that the proposed method efficiently generates high-quality approximate fronts, substantially enhancing decision-making flexibility by revealing a spectrum of viable trade-offs between utility and cost.
š Abstract
In many data-mining applications, including recommender systems, influence maximization, and team formation, the goal is to pick a subset of elements (e.g., items, nodes in a network, experts to perform a task) to maximize a monotone submodular utility function while simultaneously minimizing a cost function. Classical formulations model this tradeoff via cardinality or knapsack constraints, or by combining utility and cost into a single weighted objective. However, such approaches require committing to a specific tradeoff in advance and return only a single solution, offering limited insight into the space of viable utility-cost tradeoffs. In this paper, we depart from the single-solution paradigm and examine the problem of computing representative sets of high-quality solutions that expose different tradeoffs between submodular utility and cost. For this, we introduce $(α_1,α_2)$-approximate Pareto frontiers that provably approximate the achievable tradeoffs between submodular utility and cost. Specifically, we formalize the Pareto-$\langle f,c \rangle$ problem and develop efficient algorithms for multiple instantiations arising from different combinations of submodular utility $f$ and cost functions $c$. Our results offer a principled and practical framework for understanding and exploiting utility-cost tradeoffs in submodular optimization. Experiments on datasets from diverse application domains demonstrate that our algorithms efficiently compute approximate Pareto frontiers in practice.