Ragnar Nevries

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Let G = (V,E) be a graph. A vertex dominates itself and all its neighbors, i.e., every vertex v ∈ V dominates its closed neighborhood N [v]. A vertex set D in G is an efficient dominating (e.d.) set for G if for every vertex v ∈ V , there is exactly one d ∈ D dominating v. An edge set M ⊆ E is an efficient edge dominating (e.e.d.) set for G if it is an(More)
The problem of two-dimensional pattern matching invariant under a given class of admissible transformationsF is to findmatches of transformed versions f (P) of a pattern P in a given text T , for all f inF . In this paper, patternmatching invariant under compositions of real valued scaling and rotation are investigated.We give a new discretization technique(More)
The class Lk of k-leaf powers consists of graphs G = (V,E) that have a k-leaf root, that is, a tree T with leaf set V , where xy ∈ E, if and only if the T -distance between x and y is at most k. Structure and linear time recognition algorithms have been found for 2-, 3-, 4-, and, to some extent, 5-leaf powers, and it is known that the union of all k-leaf(More)
Let G be a finite undirected graph. A vertex dominates itself and all its neighbors in G. A vertex set D is an efficient dominating set (e.d. for short) of G if every vertex of G is dominated by exactly one vertex of D. The Efficient Domination (ED) problem, which asks for the existence of an e.d. in G, is known to be NP-complete even for very restricted(More)
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