4 papers
A Note on Ordinal Submodularity
Satoru Fujishige, Ryuhei Mizutani
Notions of ordinal submodularity/supermodularity have been introduced and studied in the literature. We consider several classes of ordinally submodular functions defined on finite…
Minimizing Submodular Functions over Hierarchical Families
Ryuhei Mizutani
This paper considers submodular function minimization (SFM) restricted to a family of subsets. We show that SFM over complements of families with certain hierarchical structures ca…
An Approximation Algorithm for Monotone Submodular Cost Allocation
Ryuhei Mizutani
In this paper, we consider the minimum submodular cost allocation (MSCA) problem. The input of MSCA consists of nonnegative submodular functions on the gro…
A Polynomial Algorithm for Minimizing -Distant Submodular Functions
Ryuhei Mizutani
This paper considers the minimization problem of relaxed submodular functions. For a positive integer , a set function is called -distant submodular if the submodular inequal…