7 research outputs found
Hamilton-connectivity of 3-domination critical graphs with α=δ+1≥5
Author name used in this publication: C. T. Ng2007-2008 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe
Connected Domination Critical Graphs
This thesis investigates the structure of connected domination critical graphs. The characterizations developed provide an important theoretical framework for addressing a number of difficult computational problems in the areas of operations research (for example, facility locations, industrial production systems), security, communication and wireless networks, transportation and logistics networks, land surveying and computational biology. In these application areas, the problems of interest are modelled by networks and graph parameters such as domination numbers reflect the efficiency and performance of the systems
Two conjectures on 3-domination critical graphs
For a graph G = (V (G), E (G)), a set S ~ V (G) dominates G if each vertex
in V (G) \S is adjacent to a vertex in S. The domination number I (G) (independent
domination number i (G)) of G is the minimum cardinality amongst its dominating
sets (independent dominating sets). G is k-edge-domination-critical, abbreviated k-1-
critical, if the domination number k decreases whenever an edge is added. Further, G
is hamiltonian if it has a cycle that passes through each of its vertices.
This dissertation assimilates research generated by two conjectures:
Conjecture I. Every 3-1-critical graph with minimum degree at least two is hamiltonian.
Conjecture 2. If G is k-1-critical, then I ( G) = i ( G).
The recent proof of Conjecture I is consolidated and presented accessibly. Conjecture
2 remains open for k = 3 and has been disproved for k :::>: 4. The progress is
detailed and proofs of new results are presented.Mathematical ScienceM. Sc. (Mathematics