منابع مشابه
Twin signed total Roman domatic numbers in digraphs
Let $D$ be a finite simple digraph with vertex set $V(D)$ and arcset $A(D)$. A twin signed total Roman dominating function (TSTRDF) on thedigraph $D$ is a function $f:V(D)rightarrow{-1,1,2}$ satisfyingthe conditions that (i) $sum_{xin N^-(v)}f(x)ge 1$ and$sum_{xin N^+(v)}f(x)ge 1$ for each $vin V(D)$, where $N^-(v)$(resp. $N^+(v)$) consists of all in-neighbors (resp.out-neighbors) of $v$, and (...
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Let k ≥ 1 be an integer, and let G be a finite and simple graph with vertex set V (G). A signed total Italian k-dominating function (STIkDF) on a graph G is a functionf : V (G) → {−1, 1, 2} satisfying the conditions that $sum_{xin N(v)}f(x)ge k$ for each vertex v ∈ V (G), where N(v) is the neighborhood of $v$, and each vertex u with f(u)=-1 is adjacent to a vertex v with f(v)=2 or to two vertic...
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Let G be a graph. A function f : V (G) → {−1, 1} is a signed kindependence function if the sum of its function values over any closed neighborhood is at most k − 1, where k ≥ 2. The signed k-independence number of G is the maximum weight of a signed k-independence function of G. Similarly, the signed total k-independence number of G is the maximum weight of a signed total k-independence functio...
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Let D be a finite and simple digraph with vertex set V (D) and arc set A(D). A signed Roman dominating function (SRDF) on the digraph D is a function f : V (D) → {−1, 1, 2} satisfying the conditions that (i) ∑ x∈N−[v] f(x) ≥ 1 for each v ∈ V (D), where N −[v] consists of v and all inner neighbors of v, and (ii) every vertex u for which f(u) = −1 has an inner neighbor v for which f(v) = 2. The w...
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Let D be a finite digraph with the vertex set V (D) and arc set A(D). A two-valued function f : V (D) → {−1, 1} defined on the vertices of a digraph D is called a signed 2-independence function if f(N−[v]) ≤ 1 for every v in D. The weight of a signed 2-independence function is f(V (D)) = ∑ v∈V (D) f(v). The maximum weight of a signed 2independence function of D is the signed 2-independence numb...
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ژورنال
عنوان ژورنال: Filomat
سال: 2014
ISSN: 0354-5180,2406-0933
DOI: 10.2298/fil1410121v