Graph Theory with Applications to Engineering and Computer Science (Prentice Hall Series in Automatic Computation)
Connectivity of Imase and Itoh Digraphs
IEEE Transactions on Computers
The Partial Line Digraph Technique in the Design of Large Interconnection Networks
IEEE Transactions on Computers
Line Digraph Iterations and the (d, k) Digraph Problem
IEEE Transactions on Computers
Some conditions for the existence of (d,k)-digraphs
IJCCGGT'03 Proceedings of the 2003 Indonesia-Japan joint conference on Combinatorial Geometry and Graph Theory
On the nonexistence of almost Moore digraphs
European Journal of Combinatorics
Hi-index | 0.01 |
We consider in this paper the (d,k) problem for directed graphs: to maximize the number of vertices in a digraph of degree d and diameter k. For any values of d and k, we construct a graph with a number of vertices larger than (d 2−1)/d2 times the (non-attainable) Moore bound. In particular, this solves the (d,k) digraph problem for k&equil;2. We also show that these graphs can be obtained as line digraph iterations and that this technique provides us with a simple local routing algorithm for the corresponding networks.