Heights in finite projective space, and a problem on directed graphs.
Nathanson, Melvyn B., Sullivan, Blair D. (2008)
Integers
Similarity:
Nathanson, Melvyn B., Sullivan, Blair D. (2008)
Integers
Similarity:
Yair Caro, Michael S. Jacobson (2003)
Discussiones Mathematicae Graph Theory
Similarity:
For a graph G, a positive integer k, k ≥ 2, and a non-negative integer with z < k and z ≠ 1, a subset D of the vertex set V(G) is said to be a non-z (mod k) dominating set if D is a dominating set and for all x ∈ V(G), |N[x]∩D| ≢ z (mod k).For the case k = 2 and z = 0, it has been shown that these sets exist for all graphs. The problem for k ≥ 3 is unknown (the existence for even values of k and z = 0 follows from the k = 2 case.) It is the purpose of this paper to show that for k...
Jaroslav Ivančo, Z. Lastivková, A. Semaničová (2004)
Mathematica Bohemica
Similarity:
A graph is called magic (supermagic) if it admits a labelling of the edges by pairwise different (consecutive) positive integers such that the sum of the labels of the edges incident with a vertex is independent of the particular vertex. We characterize magic line graphs of general graphs and describe some class of supermagic line graphs of bipartite graphs.
Gutman, Ivan (1988)
Publications de l'Institut Mathématique. Nouvelle Série
Similarity:
Bohdan Zelinka (1983)
Časopis pro pěstování matematiky
Similarity:
Michel Mollard (2013)
Discussiones Mathematicae Graph Theory
Similarity:
Let (−→ Cm2−→ Cn) be the domination number of the Cartesian product of directed cycles −→ Cm and −→ Cn for m, n ≥ 2. Shaheen [13] and Liu et al. ([11], [12]) determined the value of (−→ Cm2−→ Cn) when m ≤ 6 and [12] when both m and n ≡ 0(mod 3). In this article we give, in general, the value of (−→ Cm2−→ Cn) when m ≡ 2(mod 3) and improve the known lower bounds for most of the remaining cases. We also disprove the conjectured formula for the case m ≡ 0(mod 3) appearing in [12]. ...