10 research outputs found

    Extreme weights in Steinhaus triangles

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    Let {0=w0<w1<w2<…<wm0=w0<w1<w2<…<wm} be the set of weights of binary Steinhaus triangles of size n , and let Wibe the set of sequences in F2n that generate triangles of weight wi. In this paper we obtain the values of wi and the corresponding sets Wi for i¿{2,3,m}i¿{2,3,m}, and partial results for i=m-1i=m-1.Peer ReviewedPostprint (author's final draft

    Paired and semipaired domination in triangulations

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    A dominating set of a graph GG is a subset DD of vertices such that every vertex not in DD is adjacent to at least one vertex in DD. A dominating set DD is paired if the subgraph induced by its vertices has a perfect matching, and semipaired if every vertex in DD is paired with exactly one other vertex in DD that is within distance 2 from it. The paired domination number, denoted by γpr(G)\gamma_{pr}(G), is the minimum cardinality of a paired dominating set of GG, and the semipaired domination number, denoted by γpr2(G)\gamma_{pr2}(G), is the minimum cardinality of a semipaired dominating set of GG. A near-triangulation is a biconnected planar graph that admits a plane embedding such that all of its faces are triangles except possibly the outer face. We show in this paper that γpr(G)2n4\gamma_{pr}(G) \le 2 \lfloor \frac{n}{4} \rfloor for any near-triangulation GG of order n4n\ge 4, and that with some exceptions, γpr2(G)2n5\gamma_{pr2}(G) \le \lfloor \frac{2n}{5} \rfloor for any near-triangulation GG of order n5n\ge 5

    Total domination in plane triangulations

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    A total dominating set of a graph G=(V,E)G=(V,E) is a subset DD of VV such that every vertex in VV is adjacent to at least one vertex in DD. The total domination number of GG, denoted by γt(G)\gamma _t (G), is the minimum cardinality of a total dominating set of GG. A near-triangulation is a biconnected planar graph that admits a plane embedding such that all of its faces are triangles except possibly the outer face. We show in this paper that γt(G)2n5\gamma _t (G) \le \lfloor \frac{2n}{5}\rfloor for any near-triangulation GG of order n5n\ge 5, with two exceptions

    Metric Dimension of Maximal Outerplanar Graphs

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    In this paper, we study the metric dimension problem in maximal outerplanar graphs. Concretely, if β(G) denotes the metric dimension of a maximal outerplanar graph G of order n, we prove that 2≤β(G)≤⌈2n5⌉ and that the bounds are tight. We also provide linear algorithms to decide whether the metric dimension of G is 2 and to build a resolving set S of size ⌈2n5⌉ for G. Moreover, we characterize all maximal outerplanar graphs with metric dimension 2

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    Abstract We give explicit formulae for obtaining the binary sequences which produce Steinhaus triangles and generalized Pascal triangles with rotational and dihedral symmetries

    Chromatic Automorphisms of Consecutive Digraphs

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