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The Roman domination and domatic numbers of a digraph | ||
| Communications in Combinatorics and Optimization | ||
| مقاله 5، دوره 4، شماره 1، تابستان 2019، صفحه 47-59 اصل مقاله (382.24 K) | ||
| نوع مقاله: Original paper | ||
| شناسه دیجیتال (DOI): 10.22049/cco.2019.26356.1101 | ||
| نویسندگان | ||
Zhihong Xie1؛ Guoliang Hao  1؛ Shouliu Wei2
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| 1College of Science, East China University of Technology, Nanchang, P. R. China | ||
| 2Department of Mathematics, Minjiang University, Fuzhou, China | ||
| چکیده | ||
| A Roman dominating function (RDF) on a digraph $D$ is a function $f: V(D)rightarrow {0,1,2}$ satisfying the condition that every vertex $v$ with $f(v)=0$ has an in-neighbor $u$ with $f(u)=2$. The weight of an RDF $f$ is the value $sum_{vin V(D)}f(v)$. The Roman domination number of a digraph $D$ is the minimum weight of an RDF on $D$. A set ${f_1,f_2,dots,f_d}$ of Roman dominating functions on $D$ with the property that $sum_{i=1}^df_i(v)le2$ for each $vin V(D)$, is called a Roman dominating family (of functions) on $D$. The maximum number of functions in a Roman dominating family on $D$ is the Roman domatic number of $D$, denoted by $d_{R}(D)$. In this paper we continue the investigation of the Roman domination number, and we initiate the study of the Roman domatic number in digraphs. We present some bounds for $d_{R}(D)$. In addition, we determine the Roman domatic number of some digraphs. | ||
| کلیدواژهها | ||
| Roman dominating function؛ Roman domination number؛ Roman domatic number؛ digraph | ||
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آمار تعداد مشاهده مقاله: 379 تعداد دریافت فایل اصل مقاله: 276 |
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