New Results on Subtractive Magic Graphs

For any edge xy in a directed graph, the subtractive edge-weight is the sum of the label of xy and the label of y minus the label of x. Similarly, for any vertex z in a directed graph, the subtractive vertex-weight of z is the sum of the label of z and all edges directed into z and all the labels of edges that are directed away from z. A subtractive magic graph has every subtractive edge and vertex weight equal to some constant k. In this paper, we will discuss variations of subtractive magic labelings on directed graphs

PELABELAN TOTAL SISI AJAIB SUPER (TSAS) PADA GABUNGAN GRAF BINTANG GANDA DAN LINTASAN

An edge-magic total (EMT) labeling on a graph G(V,E) with the vertex set V and the edge set E, where |V| = p and |E| = q, is a bijective function λ: V E {1, 2, 3, ..., p + q} with the property that for each edge (xy) of G, λ(x) + λ(xy) + λ(y) = k, for a fixed positive integer k. The labeling λ is called a super edge magic total (SEMT) if it has the property that for each vertex obtain the smallest label, (V) = {1, 2, ..., p}. A graph G(V,E) is called EMT (SEMT) if there exists an EMT (SEMT) labeling on G. Study on SEMT labeling for the union of stars and paths initiated by Figueroa-Centeno et al. [2] with graph form . Furthermore, an investigation will be conducted on SEMT labeling of double stars and path, that are 2 ; 2 ;    2  and 2 . We obtain that the graphs presented above are SEMT with the magic constants k = , , and , respectivel

New Methods for Magic Total Labelings of Graphs

University of Minnesota M.S. thesis. May 2015. Major: Mathematics. Advisors: Dalibor Froncek, Sylwia Cichacz-Przenioslo. 1 computer file (PDF); ix, 117 pages.A \textit{vertex magic total (VMT) labeling} of a graph $G=(V,E)$ is a bijection from the set of vertices and edges to the set of numbers defined by $\lambda:V\cup E\rightarrow\{1,2,\dots,|V|+|E|\}$ so that for every $x \in V$ and some integer $k$, $w(x)=\lambda(x)+\sum_{y:xy\in E}\lambda(xy)=k$. An \textit{edge magic total (EMT) labeling} is a bijection from the set of vertices and edges to the set of numbers defined by $\lambda:V\cup E\rightarrow\{1,2,\dots,|V|+|E|\}$ so that for every $xy \in E$ and some integer $k$, $w(xy)=\lambda(x)+\lambda(y)+\lambda(xy)=k$. Numerous results on labelings of many families of graphs have been published. In this thesis, we include methods that expand known VMT/EMT labelings into VMT/EMT labelings of some new families of graphs, such as unions of cycles, unions of paths, cycles with chords, tadpole graphs, braid graphs, triangular belts, wheels, fans, friendships, and more

Perfect (super) Edge-Magic Crowns

A graph G is called edge-magic if there is a bijective function f from the set of vertices and edges to the set {1,2,…,|V(G)|+|E(G)|} such that the sum f(x)+f(xy)+f(y) for any xy in E(G) is constant. Such a function is called an edge-magic labelling of G and the constant is called the valence. An edge-magic labelling with the extra property that f(V(G))={1,2,…,|V(G)|} is called super edge-magic. A graph is called perfect (super) edge-magic if all theoretical (super) edge-magic valences are possible. In this paper we continue the study of the valences for (super) edge-magic labelings of crowns Cm¿K¯¯¯¯¯n and we prove that the crowns are perfect (super) edge-magic when m=pq where p and q are different odd primes. We also provide a lower bound for the number of different valences of Cm¿K¯¯¯¯¯n, in terms of the prime factors of m.Postprint (updated version