ARS Mathematica Contemporanea

Vol. 12, num. 2, p. 235-245

DOI: 10.26493/1855-3974.896.fbf

Date of publication: 2016-01-05

Abstract:

A Langford sequence of order m and defect d can be identified with a labeling of the vertices of a path of order 2m in which each labeled from d up to d + m - 1 appears twice and in which the vertices that have been label with k are at distance k. In this paper, we introduce two generalizations of this labeling that are related to distances.

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ARS Mathematica Contemporanea

Vol. 8, num. 2, p. 365-379

Date of publication: 2015-05-29

Abstract:

A dominating set S of a graph G is called locating-dominating, LD-set for short, if every vertex v not in S is uniquely determined by the set of neighbors of v belonging to S. Locating-dominating sets of minimum cardinality are called LD-codes and the cardinality of an LD-code is the location-domination number lambda(G). An LD-set S of a graph G is global if it is an LD-set of both G and its complement G'. The global location-domination number lambda g(G) is introduced as the minimum cardinality of a global LD-set of G. In this paper, some general relations between LD-codes and the location-domination number in a graph and its complement are presented first. Next, a number of basic properties involving the global location-domination number are showed. Finally, both parameters are studied in-depth for the family of block-cactus graphs.]]>