Let ϕ = (1 + √ 5)/2 denote the golden section. We investigate relationships between unbounded iterations of the floor function applied to various combinations of ϕ and ϕ2. We...
For a fixed graph H, let Ret(H) denote the problem of deciding whether a given input graph is retractable to H. We classify the complexity of Ret(H) when H is a graph (with loops ...
A set of vertices C in a graph is convex if it contains all vertices which lie on shortest paths between vertices in C. The convex hull of a set of vertices S is the smallest conve...
K¨orner and Malvenuto asked whether one can find n n/2 linear orderings (i.e., permutations) of the first n natural numbers such that any pair of them places two consecutive int...
We study grooming for two-period optical networks, a variation of the traffic grooming problem for WDM ring networks introduced by Colbourn, Quattrocchi, and Syrotiuk. In the two-...
Jean-Claude Bermond, Charles J. Colbourn, Lucia Gi...