当前位置: X-MOL 学术J. Comb. Optim. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Secure Italian domination in graphs
Journal of Combinatorial Optimization ( IF 0.9 ) Pub Date : 2020-10-28 , DOI: 10.1007/s10878-020-00658-1
M. Dettlaff , M. Lemańska , J. A. Rodríguez-Velázquez

An Italian dominating function (IDF) on a graph G is a function \(f:V(G)\rightarrow \{0,1,2\}\) such that for every vertex v with \(f(v)=0\), the total weight of f assigned to the neighbours of v is at least two, i.e., \(\sum _{u\in N_G(v)}f(u)\ge 2\). For any function \(f:V(G)\rightarrow \{0,1,2\}\) and any pair of adjacent vertices with \(f(v) = 0\) and u with \(f(u) > 0\), the function \(f_{u\rightarrow v}\) is defined by \(f_{u\rightarrow v}(v)=1\), \(f_{u\rightarrow v}(u)=f(u)-1\) and \(f_{u\rightarrow v}(x)=f(x)\) whenever \(x\in V(G){\setminus }\{u,v\}\). A secure Italian dominating function on a graph G is defined as an IDF f which satisfies that for every vertex v with \(f(v)=0\), there exists a neighbour u with \(f(u)>0\) such that \(f_{u\rightarrow v}\) is an IDF. The weight of f is \(\omega (f)=\sum _{v\in V(G) }f(v)\). The minimum weight among all secure Italian dominating functions on G is the secure Italian domination number of G. This paper is devoted to initiating the study of the secure Italian domination number of a graph. In particular, we prove that the problem of finding this parameter is NP-hard and we obtain general bounds on it. Moreover, for certain classes of graphs, we obtain closed formulas for this novel parameter.



中文翻译:

在图表中确保意大利的统治地位

G上的意大利语支配函数(IDF)是函数\(f:V(G)\ rightarrow \ {0,1,2 \} \),使得对于每个具有\(f(v)= 0的顶点v \),分配给v的邻居的f的总权重至少为2,即\(\ sum _ {u \ in N_G(v)} f(u)\ ge 2 \)。对于任何函数\(f:V(G)\ rightarrow \ {0,1,2 \} \)和任意一对相邻顶点均为\(f(v)= 0 \)u\(f(u) > 0 \),函数\(f_ {u \ rightarrow v} \)\(f_ {u \ rightarrow v}(v)= 1 \)\(f_ {u \ rightarrow v}(u)定义= f(u)-1 \)\(f_ {u \ rightarrow v}(x)= f(x)\)每当\(x \ in V(G){\ setminus} \ {u,v \} \)时。在图上一个安全意大利控制函数G ^定义为IDF ˚F其满足,对于每一个顶点v\(F(V)= 0 \) ,存在邻居ù\(F(U)> 0 \)这样\(f_ {u \ rightarrow v} \)是IDF。f的权重为\(\ omega(f)= \ sum _ {v \ in V(G)} f(v)\)。在所有安全意大利主导功能之间的最小重量是安全意大利控制数g ^。本文致力于启动图的安全意大利支配数的研究。特别地,我们证明了找到此参数的问题是NP-难的,并且我们获得了关于它的一般边界。此外,对于某些类的图,我们获得了该新颖参数的封闭公式。

更新日期:2020-10-30
down
wechat
bug