scholarly journals On The Total Edge and Vertex Irregularity Strength of Some Graphs Obtained from Star

2019 ◽  
Vol 25 (3) ◽  
pp. 314-324
Author(s):  
Rismawati Ramdani ◽  
A.N.M Salman ◽  
Hilda Assiyatun

Let $G=(V(G),E(G))$ be a graph and $k$ be a positive integer. A total $k$-labeling of $G$ is a map $f: V(G)\cup E(G)\rightarrow \{1,2,\ldots,k \}$. The edge weight $uv$ under the labeling $f$ is denoted by $w_f(uv)$ and defined by $w_f(uv)=f(u)+f(uv)+f(v)$. The vertex weight $v$ under the labeling $f$ is denoted by $w_f(v)$ and defined by $w_f(v) = f(v) + \sum_{uv \in{E(G)}} {f(uv)}$. A total $k$-labeling of $G$ is called an edge irregular total $k$-labeling of $G$ if  $w_f(e_1)\neq w_f(e_2)$ for every two distinct edges $e_1$ and $e_2$  in $E(G)$.  The total edge irregularity strength of $G$, denoted by $tes(G)$, is the minimum $k$ for which $G$ has an edge irregular total $k$-labeling.  A total $k$-labeling of $G$ is called a vertex irregular total $k$-labeling of $G$ if  $w_f(v_1)\neq w_f(v_2)$ for every two distinct vertices $v_1$ and $v_2$ in $V(G)$.  The total vertex irregularity strength of $G$, denoted by $tvs(G)$, is the minimum $k$ for which $G$ has a vertex irregular total $k$-labeling.  In this paper, we determine the total edge irregularity strength and the total vertex irregularity strength of some graphs obtained from star, which are gear, fungus, and some copies of stars.

2018 ◽  
Vol 197 ◽  
pp. 01007
Author(s):  
Rismawati Ramdani ◽  
Muhammad Ali Ramdhani

Let G = (V (G),E(G)) be a graph and k be a positive integer. A total k-labeling of G is a map f : V (G) ∪ E(G) → {1,2...,k}. The vertex weight v under the labeling f is denoted by Wf(v) and defined by Wf(v) = f(v) + Σuv∈E(G)f(uv). A total k-labeling of G is called vertex irregular if there are no two vertices with the same weight. The total vertex irregularity strength of G, denoted by tvs(G), is the minimum k such that G has a vertex irregular total k-labeling. This labeling was introduced by Bača, Jendrol', Miller, and Ryan in 2007. Let G and H be two connected graphs. Let o be a vertex of H . The comb product between G and H, in the vertex o, denoted by G⊳o H, is a graph obtained by taking one copy of G and |V (G)| copies of H and grafting the i-th copy of H at the vertex o to the i-th vertex of G. In this paper, we determine the total vertex irregularity strength of comb product of Cn and Cm where m ∈ {1,2}.


2020 ◽  
Vol 4 (2) ◽  
pp. 91
Author(s):  
Meilin I Tilukay ◽  
A. N. M. Salman

<div class="page" title="Page 1"><div class="layoutArea"><div class="column"><p><span>Under a totally irregular total </span><em>k</em><span>-labeling of a graph </span><span><em>G</em> </span><span>= (</span><span><em>V</em>,<em>E</em></span><span>), we found that for some certain graphs, the edge-weight set </span><em>W</em><span>(</span><em>E</em><span>) and the vertex-weight set </span><em>W</em><span>(</span><em>V</em><span>) of </span><span><em>G</em> </span><span>which are induced by </span><span><em>k</em> </span><span>= </span><span>ts</span><span>(</span><em>G</em><span>), </span><em>W</em><span>(</span><em>E</em><span>) </span><span>∩ </span><em>W</em><span>(</span><em>V</em><span>) is a non empty set. For which </span><span>k</span><span>, a graph </span><span>G </span><span>has a totally irregular total labeling if </span><em>W</em><span>(</span><em>E</em><span>) </span><span>∩ </span><em>W</em><span>(</span><em>V</em><span>) = </span><span>∅</span><span>? We introduce the total disjoint irregularity strength, denoted by </span><span>ds</span><span>(</span><em>G</em><span>), as the minimum value </span><span><em>k</em> </span><span>where this condition satisfied. We provide the lower bound of </span><span>ds</span><span>(</span><em>G</em><span>) and determine the total disjoint irregularity strength of cycles, paths, stars, and complete graphs.</span></p></div></div></div>


2020 ◽  
Vol 4 (1) ◽  
pp. 10
Author(s):  
I Nengah Suparta ◽  
I Gusti Putu Suharta

<div class="page" title="Page 1"><div class="layoutArea"><div class="column"><p><span>Let </span><em>G</em><span>(</span><span><em>V</em>, <em>E</em></span><span>) </span><span>be a finite simple graph and </span><span>k </span><span>be some positive integer. A vertex </span><em>k</em><span>-labeling of graph </span><em>G</em>(<em>V,E</em>), Φ : <em>V</em> → {1,2,..., <em>k</em>}, is called edge irregular <em>k</em>-labeling if the edge weights of any two different edges in <em>G</em> are distinct, where the edge weight of <em>e</em> = <em>xy</em> ∈ <em>E</em>(<em>G</em>), w<sub>Φ</sub>(e), is defined as <em>w</em><sub>Φ</sub>(<em>e</em>) = Φ(<em>x</em>) + Φ(<em>y</em>). The edge irregularity strength for graph G is the minimum value of k such that Φ is irregular edge <em>k</em>-labeling for <em>G</em>. In this note we derive the edge irregularity strength of chain graphs <em>mK</em><sub>3</sub>−path for m ≢ 3 (mod4) and <em>C</em>[<em>C<sub>n</sub></em><sup>(<em>m</em>)</sup>] for all positive integers <em>n</em> ≡ 0 (mod 4) 3<em>n</em> and <em>m</em>. We also propose bounds for the edge irregularity strength of join graph <em>P<sub>m</sub></em> + <em>Ǩ<sub>n</sub></em> for all integers <em>m, n</em> ≥ 3.</p></div></div></div>


2020 ◽  
Vol 3 (2) ◽  
pp. 79
Author(s):  
Rismawati Ramdani

Let <em>G </em>= (<em>V</em>(<em>G</em>),<em>E</em>(<em>G</em>)) be a graph and <em>k</em> be a positive integer. A total <em>k</em>-labeling of <em>G</em> is a map <em>f</em> : <em>V</em> ∪ <em>E</em> → {1,2,3,...,<em>k</em>}. The vertex weight <em>v</em> under the labeling <em>f</em> is denoted by w_<em>f</em>(<em>v</em>) and defined by <em>w</em>_<em>f</em>(<em>v</em>) = <em>f</em>(<em>v</em>) + \sum_{uv \in{E(G)}} {<em>f</em>(<em>uv</em>)}. A total <em>k</em>-labeling of <em>G</em> is called vertex irregular if there are no two vertices with the same weight. The total vertex irregularity strength of <em>G</em>, denoted by <em>tvs</em>(<em>G</em>), is the minimum <em>k</em> such that <em>G</em> has a vertex irregular total <em>k</em>-labeling. This labelings were introduced by Baca, Jendrol, Miller, and Ryan in 2007. Let <em>G</em> and <em>H</em> be two connected graphs. Let <em>o</em> be a vertex of <em>H</em>. The comb product between <em>G</em> and <em>H</em>, denoted by <em>G </em>\rhd_o <em>H</em>, is a graph obtained by taking one copy of <em>G</em> and |<em>V</em>(<em>G</em>)| copies of <em>H</em> and grafting the i-th copy of <em>H</em> at the vertex <em>o</em> to the i-th vertex of <em>G</em>. In this paper, we determine the total vertex irregularity strength of comb product of two cycles and two stars.


2020 ◽  
Vol 87 (1-2) ◽  
pp. 83
Author(s):  
Husnul Khotimah ◽  
Yeni Susanti

Let <em>G = (V(G),E(G))</em> be a simple, connected, undirected graph with non empty vertex set <em>V(G)</em> and edge set<em> E(G)</em>. The function <em>f : V(G) ∪ E(G) ↦ </em>{1,2, ...,k} (for some positive integer k) is called an edge irregular total <em>k</em>−labeling where each two edges <em>ab</em> and<em> cd</em>, having distinct weights, that are<em> f (a)+ f (ab)+ f (b) ≠ f (c)+ f (cd)+ f (d).</em> The minimum <em>k</em> for which <em>G</em> has an edge irregular total <em>k</em>−labeling is denoted by tes<em>(G)</em> and called total edge irregularity strength of graph <em>G</em>. In this paper, we determine the exact value of the total edge irregularity strength of double fan ladder graph, centralized double fan graph, and generalized parachute graph with upper path.


Author(s):  
Nurdin Hinding ◽  
Hye Kyung Kim ◽  
Nurtiti Sunusi ◽  
Riskawati Mise

For a simple graph G with a vertex set V G and an edge set E G , a labeling f : V G ∪ ​ E G ⟶ 1,2 , ⋯ , k is called a vertex irregular total k − labeling of G if for any two different vertices x and y in V G we have w t x ≠ w t y where w t x = f x + ∑ u ∈ V G f x u . The smallest positive integer k such that G has a vertex irregular total k − labeling is called the total vertex irregularity strength of G , denoted by tvs G . The lower bound of tvs G for any graph G have been found by Baca et. al. In this paper, we determined the exact value of the total vertex irregularity strength of the hexagonal cluster graph on n cluster for n ≥ 2 . Moreover, we show that the total vertex irregularity strength of the hexagonal cluster graph on n cluster is 3 n 2 + 1 / 2 .


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