Results 31 to 40 of about 228 (85)

Bounds on Watching and Watching Graph Products

open access: yesDiscussiones Mathematicae Graph Theory, 2022
A watchman’s walk for a graph G is a minimum-length closed dominating walk, and the length of such a walk is denoted (G). We introduce several lower bounds for such walks, and apply them to determine the length of watchman’s walks in several grids.
Dyer Danny, Howell Jared
doaj   +1 more source

Improving the Efficiency of Fuzzy Graphs and Their Complements Using Some Influencing Parameters

open access: yesJournal of Mathematics, Volume 2025, Issue 1, 2025.
This study focuses on constructing optimal network structures for fuzzy graph (FG) products. In graph theory, the complement of a FG product is essential since it analyses alternate interactions between the vertices. Such a complement is used to represent situations in which specific connections are deliberately excluded, which helps to understand ...
A. Meenakshi   +4 more
wiley   +1 more source

On The Total Roman Domination in Trees

open access: yesDiscussiones Mathematicae Graph Theory, 2019
A total Roman dominating function on a graph G is a function f : V (G) → {0, 1, 2} satisfying the following conditions: (i) every vertex u for which f(u) = 0 is adjacent to at least one vertex v for which f(v) = 2 and (ii) the subgraph of G induced by ...
Amjadi Jafar   +2 more
doaj   +1 more source

On Well-Covered Direct Products

open access: yesDiscussiones Mathematicae Graph Theory, 2022
A graph G is well-covered if all maximal independent sets of G have the same cardinality. In 1992 Topp and Volkmann investigated the structure of well-covered graphs that have nontrivial factorizations with respect to some of the standard graph products.
Kuenzel Kirsti, Rall Douglas F.
doaj   +1 more source

A Study on Variants of Status Unequal Coloring in Graphs and Its Properties

open access: yesJournal of Mathematics, Volume 2024, Issue 1, 2024.
Let G∧ be a simple connected graph with vertex set ϑG∧ and edge set ξG∧. The status of a vertex p∈ϑG∧ is defined as ∑q≠pd(p, q). A subset P of ϑG∧ is called a status unequal dominating set (stu‐dominating set) of G∧; for every q∈ϑ−P, there exists p in P such that p and q are adjacent and st(p) ≠ st(q).
Parvathy Gnana Sambandam   +4 more
wiley   +1 more source

Bipartite graphs with close domination and k-domination numbers

open access: yesOpen Mathematics, 2020
Let kk be a positive integer and let GG be a graph with vertex set V(G)V(G). A subset D⊆V(G)D\subseteq V(G) is a kk-dominating set if every vertex outside DD is adjacent to at least kk vertices in DD. The kk-domination number γk(G){\gamma }_{k}(G) is the
Ekinci Gülnaz Boruzanlı   +1 more
doaj   +1 more source

Perfect Roman {3}‐Domination in Graphs: Complexity and Bound of Perfect Roman {3}‐Domination Number of Trees

open access: yesJournal of Mathematics, Volume 2024, Issue 1, 2024.
A perfect Roman {3}‐dominating function on a graph G = (V, E) is a function f : V⟶{0, 1, 2, 3} having the property that if f(v) = 0, then ∑u∈N(v)f(u) = 3, and if f(v) = 1, then ∑u∈N(v)f(u) = 2 for any vertex v ∈ V. The weight of a perfect Roman {3}‐dominating function f is the sum ∑v∈Vf(v).
Ahlam Almulhim, Santi Spadaro
wiley   +1 more source

A Constructive Characterization of Vertex Cover Roman Trees

open access: yesDiscussiones Mathematicae Graph Theory, 2021
A Roman dominating function on a graph G = (V (G), E(G)) is a function f : V (G) → {0, 1, 2} satisfying the condition that every vertex u for which f (u) = 0 is adjacent to at least one vertex v for which f (v) = 2.
Martínez Abel Cabrera   +2 more
doaj   +1 more source

Changing and Unchanging of the Domination Number of a Graph: Path Addition Numbers

open access: yesDiscussiones Mathematicae Graph Theory, 2021
Given a graph G =(V, E) and two its distinct vertices u and v, the (u, v)-Pk-addition graph of G is the graph Gu,v,k−2 obtained from disjoint union of G and a path Pk : x0, x1,...,xk−1, k ≥ 2, by identifying the vertices u and x0, and identifying the ...
Samodivkin Vladimir
doaj   +1 more source

Independent Transversal Total Domination Versus Total Domination in Trees

open access: yesDiscussiones Mathematicae Graph Theory, 2021
A subset of vertices in a graph G is a total dominating set if every vertex in G is adjacent to at least one vertex in this subset. The total domination number of G is the minimum cardinality of any total dominating set in G and is denoted by γt(G).
Martínez Abel Cabrera   +2 more
doaj   +1 more source

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