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An Optimal Edge-Robust Identifying Code in the Triangular Lattice
Iiro Honkala
Department of Mathematics, University of Turku, 20014 Turku, Finland
Annals of Combinatorics 8 (3) p.303-323 September, 2004
AMS Subject Classification:05C70, 68R10, 94B65
A subset C of vertices in an undirected graph G=(V, E) is called a 1-identifying code if the sets I(v) ={uC : d(u, v)1}, vV, are non-empty and no two of them are the same set. A 1-identifying code C is called 1-edge-robust 1-identifying if it is 1-identifying in every graph G1 obtained from G by deleting or adding one edge. It is shown that the optimal density of a 1-edge-robust 1-identifying code in the infinite triangular lattice is 3/7.
Keywords: identifying code, triangular lattice, density, graph


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