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Tytuł:
Domination Parameters of a Graph and its Complement
Autorzy:
Desormeaux, Wyatt J.
Haynes, Teresa W.
Henning, Michael A.
Powiązania:
https://bibliotekanauki.pl/articles/31342430.pdf
Data publikacji:
2018-02-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
domination
complement
total domination
connected domination
clique domination
restrained domination
Opis:
A dominating set in a graph G is a set S of vertices such that every vertex in V (G) \ S is adjacent to at least one vertex in S, and the domination number of G is the minimum cardinality of a dominating set of G. Placing constraints on a dominating set yields different domination parameters, including total, connected, restrained, and clique domination numbers. In this paper, we study relationships among domination parameters of a graph and its complement.
Źródło:
Discussiones Mathematicae Graph Theory; 2018, 38, 1; 203-215
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Total Domination Versus Paired-Domination in Regular Graphs
Autorzy:
Cyman, Joanna
Dettlaff, Magda
Henning, Michael A.
Lemańska, Magdalena
Raczek, Joanna
Powiązania:
https://bibliotekanauki.pl/articles/31342314.pdf
Data publikacji:
2018-05-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
domination
total domination
paired-domination
Opis:
A subset S of vertices of a graph G is a dominating set of G if every vertex not in S has a neighbor in S, while S is a total dominating set of G if every vertex has a neighbor in S. If S is a dominating set with the additional property that the subgraph induced by S contains a perfect matching, then S is a paired-dominating set. The domination number, denoted γ(G), is the minimum cardinality of a dominating set of G, while the minimum cardinalities of a total dominating set and paired-dominating set are the total domination number, γt(G), and the paired-domination number, γpr(G), respectively. For k ≥ 2, let G be a connected k-regular graph. It is known [Schaudt, Total domination versus paired domination, Discuss. Math. Graph Theory 32 (2012) 435–447] that γpr(G)/γt(G) ≤ (2k)/(k+1). In the special case when k = 2, we observe that γpr(G)/γt(G) ≤ 4/3, with equality if and only if G ≅ C5. When k = 3, we show that γpr(G)/γt(G) ≤ 3/2, with equality if and only if G is the Petersen graph. More generally for k ≥ 2, if G has girth at least 5 and satisfies γpr(G)/γt(G) = (2k)/(k + 1), then we show that G is a diameter-2 Moore graph. As a consequence of this result, we prove that for k ≥ 2 and k ≠ 57, if G has girth at least 5, then γpr(G)/γt(G) ≤ (2k)/(k +1), with equality if and only if k = 2 and G ≅ C5 or k = 3 and G is the Petersen graph.
Źródło:
Discussiones Mathematicae Graph Theory; 2018, 38, 2; 573-586
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Vertices belonging to all or to no minimum locating dominating sets of trees
Autorzy:
Blidia, M.
Lounes, R.
Powiązania:
https://bibliotekanauki.pl/articles/255510.pdf
Data publikacji:
2009
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
domination
locating domination
Opis:
A set D of vertices in a graph G is a locating-dominating set if for every two vertices u, v of G \ D the sets N(u) ∩ D and N (v) ∩ D are non-empty and different. In this paper, we characterize vertices that are in all or in no minimum locating dominating sets in trees. The characterization guarantees that the γL-excellent tree can be recognized in a polynomial time.
Źródło:
Opuscula Mathematica; 2009, 29, 1; 5-14
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Graphs with equal domination and certified domination numbers
Autorzy:
Dettlaff, Magda
Lemańska, Magdalena
Miotk, Mateusz
Topp, Jerzy
Ziemann, Radosław
Żyliński, Paweł
Powiązania:
https://bibliotekanauki.pl/articles/255932.pdf
Data publikacji:
2019
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
domination
certified domination
Opis:
A set D of vertices of a graph G = (VG, EG) is a dominating set of G if every vertex in VG — D is adjacent to at least one vertex in D. The domination number (upper domination number, respectively) of G, denoted by [formula], respectively), is the cardinality of a smallest (largest minimal, respectively) dominating set of G. A subset D ⊆ VG is called a certified dominating set of G if D is a dominating set of G and every vertex in D has either zero or at least two neighbors in VG — D. The cardinality of a smallest (largest minimal, respectively) certified dominating set of G is called the certified (upper certified, respectively) domination number of G and is denoted by [formula]), respectively). In this paper relations between domination, upper domination, certified domination and upper certified domination numbers of a graph are studied.
Źródło:
Opuscula Mathematica; 2019, 39, 6; 815-827
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Trees with unique minimum total dominating sets
Autorzy:
Haynes, Teresa
Henning, Michael
Powiązania:
https://bibliotekanauki.pl/articles/743354.pdf
Data publikacji:
2002
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
domination
total domination
Opis:
A set S of vertices of a graph G is a total dominating set if every vertex of V(G) is adjacent to some vertex in S. We provide three equivalent conditions for a tree to have a unique minimum total dominating set and give a constructive characterization of such trees.
Źródło:
Discussiones Mathematicae Graph Theory; 2002, 22, 2; 233-246
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Minimal Graphs with Disjoint Dominating and Paired-Dominating Sets
Autorzy:
Henning, Michael A.
Topp, Jerzy
Powiązania:
https://bibliotekanauki.pl/articles/32222686.pdf
Data publikacji:
2021-08-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
domination
paired-domination
Opis:
A subset D ⊆ VG is a dominating set of G if every vertex in VG – D has a neighbor in D, while D is a paired-dominating set of G if D is a dominating set and the subgraph induced by D contains a perfect matching. A graph G is a DPDP -graph if it has a pair (D, P) of disjoint sets of vertices of G such that D is a dominating set and P is a paired-dominating set of G. The study of the DPDP -graphs was initiated by Southey and Henning [Cent. Eur. J. Math. 8 (2010) 459–467; J. Comb. Optim. 22 (2011) 217–234]. In this paper, we provide conditions which ensure that a graph is a DPDP -graph. In particular, we characterize the minimal DPDP -graphs.
Źródło:
Discussiones Mathematicae Graph Theory; 2021, 41, 3; 827-847
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A remark on the (2,2)-domination number
Autorzy:
Korneffel, Torsten
Meierling, Dirk
Volkmann, Lutz
Powiązania:
https://bibliotekanauki.pl/articles/743033.pdf
Data publikacji:
2008
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
domination
distance domination number
p-domination number
Opis:
A subset D of the vertex set of a graph G is a (k,p)-dominating set if every vertex v ∈ V(G)∖D is within distance k to at least p vertices in D. The parameter $γ_{k,p}(G)$ denotes the minimum cardinality of a (k,p)-dominating set of G. In 1994, Bean, Henning and Swart posed the conjecture that $γ_{k,p}(G) ≤ (p/(p+k))n(G)$ for any graph G with δₖ(G) ≥ k+p-1, where the latter means that every vertex is within distance k to at least k+p-1 vertices other than itself. In 2005, Fischermann and Volkmann confirmed this conjecture for all integers k and p for the case that p is a multiple of k. In this paper we show that $γ_{2,2}(G) ≤ (n(G)+1)/2$ for all connected graphs G and characterize all connected graphs with $γ_{2,2} = (n+1)/2$. This means that for k = p = 2 we characterize all connected graphs for which the conjecture is true without the precondition that δ₂ ≥ 3.
Źródło:
Discussiones Mathematicae Graph Theory; 2008, 28, 2; 361-366
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characterization of block graphs with equal 2-domination number and domination number plus one
Autorzy:
Hansberg, Adriana
Volkmann, Lutz
Powiązania:
https://bibliotekanauki.pl/articles/743677.pdf
Data publikacji:
2007
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
domination
2-domination
multiple domination
block graph
Opis:
Let G be a simple graph, and let p be a positive integer. A subset D ⊆ V(G) is a p-dominating set of the graph G, if every vertex v ∈ V(G)-D is adjacent with at least p vertices of D. The p-domination number γₚ(G) is the minimum cardinality among the p-dominating sets of G. Note that the 1-domination number γ₁(G) is the usual domination number γ(G).
If G is a nontrivial connected block graph, then we show that γ₂(G) ≥ γ(G)+1, and we characterize all connected block graphs with γ₂(G) = γ(G)+1. Our results generalize those of Volkmann [12] for trees.
Źródło:
Discussiones Mathematicae Graph Theory; 2007, 27, 1; 93-103
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Total Domination in Generalized Prisms and a New Domination Invariant
Autorzy:
Tepeh, Aleksandra
Powiązania:
https://bibliotekanauki.pl/articles/32222717.pdf
Data publikacji:
2021-11-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
domination
k -rainbow total domination
total domination
Opis:
In this paper we complement recent studies on the total domination of prisms by considering generalized prisms, i.e., Cartesian products of an arbitrary graph and a complete graph. By introducing a new domination invariant on a graph G, called the k-rainbow total domination number and denoted by γkrt(G), it is shown that the problem of finding the total domination number of a generalized prism G □ Kk is equivalent to an optimization problem of assigning subsets of {1, 2, . . ., k} to vertices of G. Various properties of the new domination invariant are presented, including, inter alia, that γkrt(G) = n for a nontrivial graph G of order n as soon as k ≥ 2Δ(G). To prove the mentioned result as well as the closed formulas for the k-rainbow total domination number of paths and cycles for every k, a new weight-redistribution method is introduced, which serves as an efficient tool for establishing a lower bound for a domination invariant.
Źródło:
Discussiones Mathematicae Graph Theory; 2021, 41, 4; 1165-1178
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the Complexity of Reinforcement in Graphs
Autorzy:
Rad, Nader Jafari
Powiązania:
https://bibliotekanauki.pl/articles/31340751.pdf
Data publikacji:
2016-11-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
domination
total domination
total restrained domination
p- domination
k-rainbow domination
reinforcement
NP-hard
Opis:
We show that the decision problem for p-reinforcement, p-total rein- forcement, total restrained reinforcement, and k-rainbow reinforcement are NP-hard for bipartite graphs.
Źródło:
Discussiones Mathematicae Graph Theory; 2016, 36, 4; 877-887
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Some remarks on α-domination
Autorzy:
Dahme, Franz
Rautenbach, Dieter
Volkmann, Lutz
Powiązania:
https://bibliotekanauki.pl/articles/744557.pdf
Data publikacji:
2004
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
α-domination
domination
Opis:
Let α ∈ (0,1) and let $G = (V_G,E_G$) be a graph. According to Dunbar, Hoffman, Laskar and Markus [3] a set $D ⊆ V_G$ is called an α-dominating set of G, if $|N_G(u) ∩ D| ≥ αd_G(u)$ for all $u ∈ V_G∖D$. We prove a series of upper bounds on the α-domination number of a graph G defined as the minimum cardinality of an α-dominating set of G.
Źródło:
Discussiones Mathematicae Graph Theory; 2004, 24, 3; 423-430
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Paired-domination
Autorzy:
Fitzpatrick, S.
Hartnell, B.
Powiązania:
https://bibliotekanauki.pl/articles/744199.pdf
Data publikacji:
1998
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
domination
paired-domination
matching
Opis:
We are interested in dominating sets (of vertices) with the additional property that the vertices in the dominating set can be paired or matched via existing edges in the graph. This could model the situation of guards or police where each has a partner or backup. This paper will focus on those graphs in which the number of matched pairs of a minimum dominating set of this type equals the size of some maximal matching in the graph. In particular, we characterize the leafless graphs of girth seven or more of this type.
Źródło:
Discussiones Mathematicae Graph Theory; 1998, 18, 1; 63-72
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Graphs With Large Semipaired Domination Number
Autorzy:
Haynes, Teresa W.
Henning, Michael A.
Powiązania:
https://bibliotekanauki.pl/articles/31343332.pdf
Data publikacji:
2019-08-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
paired-domination
semipaired domination
Opis:
Let $G$ be a graph with vertex set $V$ and no isolated vertices. A subset $ S \subseteq V $ is a semipaired dominating set of $G$ if every vertex in $ V \backslash S $ is adjacent to a vertex in $S$ and $S$ can be partitioned into two element subsets such that the vertices in each subset are at most distance two apart. The semipaired domination number $ \gamma_{pr2}(G) $ is the minimum cardinality of a semipaired dominating set of $G$. We show that if $G$ is a connected graph $G$ of order $ n \ge 3 $, then \( \gamma_{pr2} (G) \le \tfrac{2}{3} n \), and we characterize the extremal graphs achieving equality in the bound.
Źródło:
Discussiones Mathematicae Graph Theory; 2019, 39, 3; 659-671
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Bounds on perfect k-domination in trees: an algorithmic approach
Autorzy:
Chaluvaraju, B.
Vidya, K. A.
Powiązania:
https://bibliotekanauki.pl/articles/255985.pdf
Data publikacji:
2012
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
k-domination
perfect domination
perfect k-domination
Opis:
Let k be a positive integer and G = (V, E) be a graph. A vertex subset D of a graph G is called a perfect k-dominating set of G if every vertex v of G not in D is adjacent to exactly k vertices of D. The minimum cardinality of a perfect k -dominating set of G is the perfect k-domination number γkp (G ). In this paper, a sharp bound for γkp (T) is obtained where T is a tree.
Źródło:
Opuscula Mathematica; 2012, 32, 4; 707-714
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A note on domination parameters in random graphs
Autorzy:
Bonato, Anthony
Wang, Changping
Powiązania:
https://bibliotekanauki.pl/articles/743019.pdf
Data publikacji:
2008
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
domination
random graphs
independent domination
total domination
Opis:
Domination parameters in random graphs G(n,p), where p is a fixed real number in (0,1), are investigated. We show that with probability tending to 1 as n → ∞, the total and independent domination numbers concentrate on the domination number of G(n,p).
Źródło:
Discussiones Mathematicae Graph Theory; 2008, 28, 2; 335-343
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A New Upper Bound for the Perfect Italian Domination Number of a Tree
Autorzy:
Nazari-Moghaddam, Sakineh
Chellali, Mustapha
Powiązania:
https://bibliotekanauki.pl/articles/32304138.pdf
Data publikacji:
2022-08-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
Italian domination
Roman domination
perfect Italian domination
Opis:
A perfect Italian dominating function (PIDF) on a graph $G$ is a function $ f : V (G) \rightarrow \{ 0, 1, 2 \} $ satisfying the condition that for every vertex u with $f(u) = 0$, the total weight of $f$ assigned to the neighbors of $u$ is exactly two. The weight of a PIDF is the sum of its functions values over all vertices. The perfect Italian domination number of $G$, denoted $ \gamma_I^p (G) $, is the minimum weight of a PIDF of $G$. In this paper, we show that for every tree $T$ of order $ n \ge 3 $, with $ \mathcal{l} (T) $ leaves and $s(T)$ support vertices, \( \gamma_I^p (T) \ge \tfrac {4n- \mathscr{l}(T) + 2s (T) - 1}{5} \), improving a previous bound given by T.W. Haynes and M.A. Henning in [Perfect Italian domination in trees, Discrete Appl. Math. 260 (2019) 164–177].
Źródło:
Discussiones Mathematicae Graph Theory; 2022, 42, 3; 1005-1022
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A characterization of (γₜ,γ₂)-trees
Autorzy:
Lu, You
Hou, Xinmin
Xu, Jun-Ming
Li, Ning
Powiązania:
https://bibliotekanauki.pl/articles/744036.pdf
Data publikacji:
2010
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
domination
total domination
2-domination
(λ,μ)-tree
Opis:
Let γₜ(G) and γ₂(G) be the total domination number and the 2-domination number of a graph G, respectively. It has been shown that: γₜ(T) ≤ γ₂(T) for any tree T. In this paper, we provide a constructive characterization of those trees with equal total domination number and 2-domination number.
Źródło:
Discussiones Mathematicae Graph Theory; 2010, 30, 3; 425-435
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the Total k-Domination in Graphs
Autorzy:
Bermudo, Sergio
Hernández-Gómez, Juan C.
Sigarreta, José M.
Powiązania:
https://bibliotekanauki.pl/articles/31342422.pdf
Data publikacji:
2018-02-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
k -domination
total k -domination
k -tuple domination
k -tuple total domination
Opis:
Let G=(V, E) be a graph; a set S ⊆ V is a total k-dominating set if every vertex v ∈ V has at least k neighbors in S. The total k-domination number γkt(G) is the minimum cardinality among all total k-dominating sets. In this paper we obtain several tight bounds for the total k-domination number of a graph. In particular, we investigate the relationship between the total k-domination number of a graph and the order, the size, the girth, the minimum and maximum degree, the diameter, and other domination parameters of the graph.
Źródło:
Discussiones Mathematicae Graph Theory; 2018, 38, 1; 301-317
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Protection of Lexicographic Product Graphs
Autorzy:
Klein, Douglas J.
Rodríguez-Velázquez, Juan A.
Powiązania:
https://bibliotekanauki.pl/articles/32361746.pdf
Data publikacji:
2022-02-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
lexicographic product
weak Roman domination
secure domination
total domination
double total domination
Opis:
In this paper, we study the weak Roman domination number and the secure domination number of lexicographic product graphs. In particular, we show that these two parameters coincide for almost all lexicographic product graphs. Furthermore, we obtain tight bounds and closed formulas for these parameters.
Źródło:
Discussiones Mathematicae Graph Theory; 2022, 42, 1; 139-158
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Full domination in graphs
Autorzy:
Brigham, Robert
Chartrand, Gary
Dutton, Ronald
Zhang, Ping
Powiązania:
https://bibliotekanauki.pl/articles/743419.pdf
Data publikacji:
2001
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
full domination
full star domination
full closed domination
full open domination
Opis:
For each vertex v in a graph G, let there be associated a subgraph $H_v$ of G. The vertex v is said to dominate $H_v$ as well as dominate each vertex and edge of $H_v$. A set S of vertices of G is called a full dominating set if every vertex of G is dominated by some vertex of S, as is every edge of G. The minimum cardinality of a full dominating set of G is its full domination number $γ_{FH}(G)$. A full dominating set of G of cardinality $γ_{FH}(G)$ is called a $γ_{FH}$-set of G. We study three types of full domination in graphs: full star domination, where $H_v$ is the maximum star centered at v, full closed domination, where $H_v$ is the subgraph induced by the closed neighborhood of v, and full open domination, where $H_v$ is the subgraph induced by the open neighborhood of v.
Źródło:
Discussiones Mathematicae Graph Theory; 2001, 21, 1; 43-62
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A note on a relation between the weak and strong domination numbers of a graph
Autorzy:
Boutrig, R.
Chellali, M.
Powiązania:
https://bibliotekanauki.pl/articles/255983.pdf
Data publikacji:
2012
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
weak domination
strong domination
Opis:
In a graph G = (V, E) a vertex is said to dominate itself and all its neighbors. A set D ⊆ V is a weak (strong, respectively) dominating set of G if every vertex v ∈ V - S is adjacent to a vertex u ∈ D such that dG(v) ≥ dG(u) (dG(v) ≤ dG(u), respectively). The weak (strong, respectively) domination number of G, denoted by ϒw(G) (ϒs(G), respectively), is the minimum cardinality of a weak (strong, respectively) dominating set of G. In this note we show that if G is a connected graph of order n ≥ 3, then ϒw(G) + tϒs(G) ≤ n, where t = 3/(Δ+1) if G is an arbitrary graph, t = 3/5 if G is a block graph, and t = 2/3 if G is a claw free graph.
Źródło:
Opuscula Mathematica; 2012, 32, 2; 235-238
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Efficient (j,k)-domination
Autorzy:
Rubalcaba, Robert
Slater, Peter
Powiązania:
https://bibliotekanauki.pl/articles/743411.pdf
Data publikacji:
2007
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
efficient domination
multiple domination
Opis:
A dominating set S of a graph G is called efficient if |N[v]∩ S| = 1 for every vertex v ∈ V(G). That is, a dominating set S is efficient if and only if every vertex is dominated exactly once. In this paper, we investigate efficient multiple domination. There are several types of multiple domination defined in the literature: k-tuple domination, {k}-domination, and k-domination. We investigate efficient versions of the first two as well as a new type of multiple domination.
Źródło:
Discussiones Mathematicae Graph Theory; 2007, 27, 3; 409-423
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Vertices Contained In All Or In No Minimum Semitotal Dominating Set Of A Tree
Autorzy:
Henning, Michael A.
Marcon, Alister J.
Powiązania:
https://bibliotekanauki.pl/articles/31341173.pdf
Data publikacji:
2016-02-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
domination
semitotal domination
trees
Opis:
Let G be a graph with no isolated vertex. In this paper, we study a parameter that is squeezed between arguably the two most important domination parameters; namely, the domination number, γ(G), and the total domination number, γt(G). A set S of vertices in a graph G is a semitotal dominating set of G if it is a dominating set of G and every vertex in S is within distance 2 of another vertex of S. The semitotal domination number, γt2(G), is the minimum cardinality of a semitotal dominating set of G. We observe that γ(G) ≤ γt2(G) ≤ γt(G). We characterize the set of vertices that are contained in all, or in no minimum semitotal dominating set of a tree.
Źródło:
Discussiones Mathematicae Graph Theory; 2016, 36, 1; 71-93
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Some Progress on the Double Roman Domination in Graphs
Autorzy:
Rad, Nader Jafari
Rahbani, Hadi
Powiązania:
https://bibliotekanauki.pl/articles/31343730.pdf
Data publikacji:
2019-02-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
Roman domination
double Roman domination
Opis:
For a graph $ G = (V,E) $, a double Roman dominating function (or just DRDF) is a function $ f : V \rightarrow {0, 1, 2, 3} $ having the property that if $ f(v) = 0 $ for a vertex $ v $, then $ v $ has at least two neighbors assigned 2 under $ f $ or one neighbor assigned 3 under $ f $, and if $ f(v) = 1 $, then vertex $ v $ must have at least one neighbor $ w $ with $ f(w) \ge 2 $. The weight of a DRDF $f$ is the sum $f(V) = \Sigma_{ v \in V } f(v) $, and the minimum weight of a DRDF on $G$ is the double Roman domination number of $G$, denoted by $ \gamma_{dR} (G) $. In this paper, we derive sharp upper and lower bounds on $ \gamma_{dR} (G) + \gamma_{dR} ( \overline{G} ) $ and also $ \gamma_{dR} (G ) \gamma_{dR} ( \overline{G} ) $, where $ \overline{G} $ is the complement of graph $G$. We also show that the decision problem for the double Roman domination number is NP- complete even when restricted to bipartite graphs and chordal graphs.
Źródło:
Discussiones Mathematicae Graph Theory; 2019, 39, 1; 41-53
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Roman {2}-Domination Problem in Graphs
Autorzy:
Chen, Hangdi
Lu, Changhong
Powiązania:
https://bibliotekanauki.pl/articles/32314051.pdf
Data publikacji:
2022-05-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
Roman {2}-domination
domination
algorithms
Opis:
For a graph G = (V, E), a Roman {2}-dominating function (R2DF) f : V → {0, 1, 2} has the property that for every vertex v ∈ V with f(v) = 0, either there exists a neighbor u ∈ N(v), with f(u) = 2, or at least two neighbors x, y ∈ N(v) having f(x) = f(y) = 1. The weight of an R2DF f is the sum f(V) = ∑v∈V f(v), and the minimum weight of an R2DF on G is the Roman {2}-domination number γ{R2}(G). An R2DF is independent if the set of vertices having positive function values is an independent set. The independent Roman {2}-domination number i{R2}(G) is the minimum weight of an independent Roman {2}-dominating function on G. In this paper, we show that the decision problem associated with γ{R2}(G) is NP-complete even when restricted to split graphs. We design a linear time algorithm for computing the value of i{R2}(T) in any tree T, which answers an open problem raised by Rahmouni and Chellali [Independent Roman {2}-domination in graphs, Discrete Appl. Math. 236 (2018) 408–414]. Moreover, we present a linear time algorithm for computing the value of γ{R2}(G) in any block graph G, which is a generalization of trees.
Źródło:
Discussiones Mathematicae Graph Theory; 2022, 42, 2; 641-660
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł

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