3471 search results - page 110 / 695 » Obstacle Numbers of Graphs |
ALGORITHMICA
2010
13 years 7 months ago
2010
The problem of computing the chromatic number of a P5-free graph (a graph which contains no path on 5 vertices as an induced subgraph) is known to be NP-hard. However, we show tha...
COMBINATORICS
1999
13 years 9 months ago
1999
It is proven that for every fixed h, a and b, a graph with n vertices and minimum degree at least h-1 h n, which contains no copy of Kb (the complete graph with b vertices), conta...
COMBINATORICS
2007
13 years 9 months ago
2007
We determine the exact and asymptotic number of unlabeled outerplanar graphs. The exact number gn of unlabeled outerplanar graphs on n vertices can be computed in polynomial time,...
DM
1998
13 years 9 months ago
1998
Let G be a median graph on n vertices and m edges and let k be the number of equivalence classes of the Djokovi´c’s relation Θ defined on the edge-set of G. Then 2n − m −...
ICCS
2007
Springer
14 years 1 months ago
2007
Springer
We propose in this paper an extension of Conceptual Graphs that allows to use datatypes (strings, numbers, ...) for typing concept nodes. Though the model-theoretic semantics of th...