DM
2006
14 years 18 days ago
2006
For n, k and t such that 1 < t < k < n, a set F of subsets of [n] has the (k, t)threshold property if every k-subset of [n] contains at least t sets from F and every (k -...
DM
2006
14 years 18 days ago
2006
We provide a simple constructive characterization for trees with equal domination and independent domination numbers, and for trees with equal domination and total domination numb...
DM
2006
14 years 18 days ago
2006
We complete the enumeration of Dumont permutations of the second kind avoiding a pattern of length 4 which is itself a Dumont permutation of the second kind. We also consider some ...
DM
2006
14 years 18 days ago
2006
A directed star forest is a forest all of whose components are stars with arcs emanating from the center to the leaves. The acircuitic directed star arboricity of an oriented grap...
DM
2006
14 years 18 days ago
2006
The recursive computation of the interlace polynomial introduced by Arratia, Bollob
DM
2006
14 years 18 days ago
2006
We will present some properties of the direct limit of a direct system of multialgebras in a subcategory of the category of multialgebras obtained by considering as morphisms the i...
DM
2006
14 years 18 days ago
2006
Given a graph G, a function f : V (G) {1, 2, . . . , k} is a k-ranking of G if f (u) = f (v) implies every u - v path contains a vertex w such that f (w) > f (u). A k-ranking ...
DM
2006
14 years 18 days ago
2006
DM
2006
14 years 18 days ago
2006
Let F be a family of translates of a fixed convex set M in Rn. Let (F) and (F) denote the transversal number and the independence number of F, respectively. We show that (F) (F) 8...
DM
2006
14 years 18 days ago
2006
Let G be a connected, locally connected, claw-free graph of order n and x, y be two vertices of G. In this paper, we prove that if for any 2-cut S of G, S {x, y} = , then each (x...