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A Note on the Budgeted Maximization of Submodular Functions
Andreas Krause
出版
Carnegie Mellon University. Center for Automated Learning and Discovery
, 2005
URL
http://books.google.com.hk/books?id=MBH6PgAACAAJ&hl=&source=gbs_api
註釋
Abstract: "Many set functions F in combinatorial optimization satisfy the diminishing returns property F(A [union of] X) - F(A) [> or =] F(A' [union of] X) - F(A') for A [element of] A'. Such functions are called submodular. A result from Nemhauser et.al. states that the problem of selecting k-element subsets maximizing a nondecreasing submodular function can be approximated with a constant factor (1 - 1/e) performance guarantee. Khuller et.al. showed that for the special submodular function involved in the MAX-COVER problem, this approximation result generalizes to a budgeted setting under linear nonnegative cost-functions. In this note, we extend this result to general submodular functions. Motivated by the problem of maximizing entropy in discrete graphical models, where the submodular objective cannot be evaluated exactly, we generalize our result to account for absolute errors."