Title
Directed distance in digraphs: centers and medians
Abstract
The directed distance d(D)(u, upsilon) from a vertex u to a vertex upsilon in a strong digraph D is the length of a shortest (directed) u - upsilon path in D. The eccentricity of a vertex upsilon in D is the directed distance from upsilon to a vertex furthest from upsilon. The distance of a vertex upsilon in D is the sum of the directed distances from upsilon to the vertices of D. The center C(D) of D is the subdigraph induced by those vertices of minimum eccentricity, while the median M(D) of D is the subdigraph induced by those vertices of minimum distance. It is shown that for every two asymmetric digraphs D1 and D2, there exists a strong asymmetric digraph H such that C(H) congruent-to D1 and M(H) congruent-to D2, and where the directed distance from C(H) to M(H) and from M(H) to C(H) can be arbitrarily prescribed. Furthermore, if K is a nonempty asymmetric digraph isomorphic to an induced subdigraph of both D1 and D2, then there exists a strong asymmetric digraph F such that C(F) congruent-to D1, M(F) congruent-to D2, and C(F) and M(F) congruent-to K. (C) 1993 John Wiley & Sons, Inc.
Year
DOI
Venue
1993
10.1002/jgt.3190170408
Journal of Graph Theory
Field
DocType
Volume
Discrete mathematics,Topology,Combinatorics,Vertex (geometry),Graph isomorphism,Eccentricity (behavior),Directed graph,Isomorphism,Digraph,Mathematics
Journal
17
Issue
ISSN
Citations 
4
0364-9024
5
PageRank 
References 
Authors
0.59
1
4
Name
Order
Citations
PageRank
Gary Chartrand150.93
Garry L. Johns26811.78
Songlin Tian3193.51
Steven J. Winters4126.33