DM
2006
13 years 4 months 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
13 years 4 months 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
13 years 4 months 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
13 years 4 months 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
13 years 4 months ago
2006
The recursive computation of the interlace polynomial introduced by Arratia, Bollob
DM
2006
13 years 4 months 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
13 years 4 months 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
13 years 4 months ago
2006
DM
2006
13 years 4 months 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
13 years 4 months 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...