54 citations · 123 across the 39 of their papers we have counts for
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math.OC2014
L-extendable functions and a proximity scaling algorithm for minimum cost multiflow problem
Hiroshi Hirai
In this paper, we develop a theory of new classes of discrete convex functions, called L-extendable functions and alternating L-convex functions, defined on the product of trees. W…
math.MG2014★ 54 cited
Weakly modular graphs and nonpositive curvature
Jérémie Chalopin, Victor Chepoi, Hiroshi Hirai +1
This article investigates structural, geometrical, and topological characterizations and properties of weakly modular graphs and of cell complexes derived from them. The unifying t…
math.MG2014★ 1 cited
Discrete Convexity and Polynomial Solvability in Minimum 0-Extension Problems
Hiroshi Hirai
For a graph G and a set V containing the vertex set of G, a 0-extension of G is a metric d on V such that d extends the shortest path metric of G and for all x in V there exists a…