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Wyszukujesz frazę "dominating set" wg kryterium: Temat


Wyświetlanie 1-46 z 46
Tytuł:
Connected odd dominating sets in graphs
Autorzy:
Caro, Yair
Klostermeyer, William
Yuster, Raphael
Powiązania:
https://bibliotekanauki.pl/articles/744351.pdf
Data publikacji:
2005
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
dominating set
odd dominating set
Opis:
An odd dominating set of a simple, undirected graph G = (V,E) is a set of vertices D ⊆ V such that |N[v] ∩ D| ≡ 1 mod 2 for all vertices v ∈ V. It is known that every graph has an odd dominating set. In this paper we consider the concept of connected odd dominating sets. We prove that the problem of deciding if a graph has a connected odd dominating set is NP-complete. We also determine the existence or non-existence of such sets in several classes of graphs. Among other results, we prove there are only 15 grid graphs that have a connected odd dominating set.
Źródło:
Discussiones Mathematicae Graph Theory; 2005, 25, 3; 225-239
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Note on the Locating-Total Domination in Graphs
Autorzy:
Miller, Mirka
Rajan, R. Sundara
Jayagopal, R.
Rajasingh, Indra
Manuel, Paul
Powiązania:
https://bibliotekanauki.pl/articles/31341658.pdf
Data publikacji:
2017-08-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
dominating set
total dominating set
locating-dominating set
locating-total dominating set
regular graphs
Opis:
In this paper we obtain a sharp (improved) lower bound on the locating-total domination number of a graph, and show that the decision problem for the locating-total domination is NP-complete.
Źródło:
Discussiones Mathematicae Graph Theory; 2017, 37, 3; 745-754
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Making a Dominating Set of a Graph Connected
Autorzy:
Li, Hengzhe
Wu, Baoyindureng
Yang, Weihua
Powiązania:
https://bibliotekanauki.pl/articles/31342251.pdf
Data publikacji:
2018-11-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
independent set
dominating set
connected dominating set
Opis:
Let $ G = (V,E) $ be a graph and $ S \subseteq V $. We say that $ S $ is a dominating set of $ G $, if each vertex in $ V \backlash S $ has a neighbor in $S$. Moreover, we say that $S$ is a connected (respectively, 2-edge connected or 2-connected) dominating set of $G$ if $ G[S] $ is connected (respectively, 2-edge connected or 2-connected). The domination (respectively, connected domination, or 2-edge connected domination, or 2-connected domination) number of $G$ is the cardinality of a minimum dominating (respectively, connected dominating, or 2-edge connected dominating, or 2-connected dominating) set of $G$, and is denoted $ \gamma (G) $ (respectively $ \gamma_1 (G) $, or $ \gamma_2^′ (G) $, or $ \gamma_2 (G) $). A well-known result of Duchet and Meyniel states that $ \gamma_1 (G) \le 3 \gamma (G) − 2 $ for any connected graph $G$. We show that if $ \gamma (G) \ge 2 $, then $ \gamma_2^′ (G) \ge 5 \gamma (G) − 4 $ when $G$ is a 2-edge connected graph and $ \gamma_2 (G) \le 11 \gamma (G) − 13 $ when $G$ is a 2-connected triangle-free graph.
Źródło:
Discussiones Mathematicae Graph Theory; 2018, 38, 4; 947-962
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Odd and residue domination numbers of a graph
Autorzy:
Caro, Yair
Klostermeyer, William
Goldwasser, John
Powiązania:
https://bibliotekanauki.pl/articles/743442.pdf
Data publikacji:
2001
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
dominating set
odd dominating set
parity domination
Opis:
Let G = (V,E) be a simple, undirected graph. A set of vertices D is called an odd dominating set if |N[v] ∩ D| ≡ 1 (mod 2) for every vertex v ∈ V(G). The minimum cardinality of an odd dominating set is called the odd domination number of G, denoted by γ₁(G). In this paper, several algorithmic and structural results are presented on this parameter for grids, complements of powers of cycles, and other graph classes as well as for more general forms of "residue" domination.
Źródło:
Discussiones Mathematicae Graph Theory; 2001, 21, 1; 119-136
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Eternal Domination: Criticality and Reachability
Autorzy:
Klostermeyer, William F.
MacGillivray, Gary
Powiązania:
https://bibliotekanauki.pl/articles/31342174.pdf
Data publikacji:
2017-02-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
dominating set
eternal dominating set
critical graphs
Opis:
We show that for every minimum eternal dominating set, D, of a graph G and every vertex v ∈ D, there is a sequence of attacks at the vertices of G which can be defended in such a way that an eternal dominating set not containing v is reached. The study of the stronger assertion that such a set can be reached after a single attack is defended leads to the study of graphs which are critical in the sense that deleting any vertex reduces the eternal domination number. Examples of these graphs and tight bounds on connectivity, edge-connectivity and diameter are given. It is also shown that there exist graphs in which deletion of any edge increases the eternal domination number, and graphs in which addition of any edge decreases the eternal domination number.
Źródło:
Discussiones Mathematicae Graph Theory; 2017, 37, 1; 63-77
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hereditary Equality of Domination and Exponential Domination in Subcubic Graphs
Autorzy:
Chen, Xue-Gang
Wang, Yu-Feng
Wu, Xiao-Fei
Powiązania:
https://bibliotekanauki.pl/articles/32324524.pdf
Data publikacji:
2021-11-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
dominating set
exponential dominating set
subcubic graphs
Opis:
Let γ(G) and γe(G) denote the domination number and exponential domination number of graph G, respectively. Henning et al., in [Hereditary equality of domination and exponential domination, Discuss. Math. Graph Theory 38 (2018) 275–285] gave a conjecture: There is a finite set ℱ of graphs such that a graph G satisfies (H) = γe(H) for every induced subgraph H of G if and only if G is ℱ-free. In this paper, we study the conjecture for subcubic graphs. We characterize the class ℱ by minimal forbidden induced subgraphs and prove that the conjecture holds for subcubic graphs.
Źródło:
Discussiones Mathematicae Graph Theory; 2021, 41, 4; 1067-1075
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Independent transversal domination in graphs
Autorzy:
Hamid, Ismail
Powiązania:
https://bibliotekanauki.pl/articles/743635.pdf
Data publikacji:
2012
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
dominating set
independent set
independent transversal dominating set
Opis:
A set S ⊆ V of vertices in a graph G = (V, E) is called a dominating set if every vertex in V-S is adjacent to a vertex in S. A dominating set which intersects every maximum independent set in G is called an independent transversal dominating set. The minimum cardinality of an independent transversal dominating set is called the independent transversal domination number of G and is denoted by $γ_{it}(G)$. In this paper we begin an investigation of this parameter.
Źródło:
Discussiones Mathematicae Graph Theory; 2012, 32, 1; 5-17
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Quasiperfect domination in triangular lattices
Autorzy:
Dejter, Italo
Powiązania:
https://bibliotekanauki.pl/articles/743129.pdf
Data publikacji:
2009
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
perfect dominating set
quasiperfect dominating set
triangular lattice
Opis:
A vertex subset S of a graph G is a perfect (resp. quasiperfect) dominating set in G if each vertex v of G∖S is adjacent to only one vertex ($d_v$ ∈ {1,2} vertices) of S. Perfect and quasiperfect dominating sets in the regular tessellation graph of Schläfli symbol {3,6} and in its toroidal quotients are investigated, yielding the classification of their perfect dominating sets and most of their quasiperfect dominating sets S with induced components of the form $K_ν$, where ν ∈ {1,2,3} depends only on S.
Źródło:
Discussiones Mathematicae Graph Theory; 2009, 29, 1; 179-198
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Bounds on the Locating-Domination Number and Differentiating-Total Domination Number in Trees
Autorzy:
Rad, Nader Jafari
Rahbani, Hadi
Powiązania:
https://bibliotekanauki.pl/articles/31342324.pdf
Data publikacji:
2018-05-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
locating-dominating set
differentiating-total dominating set
tree
Opis:
A subset $S$ of vertices in a graph $G = (V,E)$ is a dominating set of $G$ if every vertex in $V − S$ has a neighbor in $S$, and is a total dominating set if every vertex in $V$ has a neighbor in $S$. A dominating set $S$ is a locating-dominating set of $G$ if every two vertices $ x, y \in V − S$ satisfy $N(x) \cap S \ne N(y) \cap S$. The locating-domination number $ \gamma_L (G) $ is the minimum cardinality of a locating-dominating set of $G$. A total dominating set $S$ is called a differentiating-total dominating set if for every pair of distinct vertices $u$ and $v$ of $G$, $ N[u] \cap S \ne N[v] \cap S $. The minimum cardinality of a differentiating-total dominating set of $G$ is the differentiating-total domination number of $G$, denoted by $ \gamma_t^D (G) $. We obtain new upper bounds for the locating-domination number, and the differentiating-total domination number in trees. Moreover, we characterize all trees achieving equality for the new bounds.
Źródło:
Discussiones Mathematicae Graph Theory; 2018, 38, 2; 455-462
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Domination, Eternal Domination, and Clique Covering
Autorzy:
Klostermeyer, William F.
Mynhardt, C.M.
Powiązania:
https://bibliotekanauki.pl/articles/31339487.pdf
Data publikacji:
2015-05-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
dominating set
eternal dominating set
independent set
clique cover
Opis:
Eternal and m-eternal domination are concerned with using mobile guards to protect a graph against infinite sequences of attacks at vertices. Eternal domination allows one guard to move per attack, whereas more than one guard may move per attack in the m-eternal domination model. Inequality chains consisting of the domination, eternal domination, m-eternal domination, independence, and clique covering numbers of graph are explored in this paper. Among other results, we characterize bipartite and triangle-free graphs with domination and eternal domination numbers equal to two, trees with equal m-eternal domination and clique covering numbers, and two classes of graphs with equal domination, eternal domination and clique covering numbers.
Źródło:
Discussiones Mathematicae Graph Theory; 2015, 35, 2; 283-300
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On minimum intersections of certain secondary dominating sets in graphs
Autorzy:
Kosiorowska, Anna
Michalski, Adrian
Włoch, Iwona
Powiązania:
https://bibliotekanauki.pl/articles/29519420.pdf
Data publikacji:
2023
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
dominating set
2-dominating set
(1, 2)-dominating set
proper (1, 2)-dominating set
domination number
(1,2)-intersection index
Opis:
In this paper we consider secondary dominating sets, also named as (1,k)-dominating sets, introduced by Hedetniemi et al. in 2008. In particular, we study intersections of the (1, 1)-dominating sets and proper (1, 2)-dominating sets. We introduce (1,2̅)-intersection index as the minimum possible cardinality of such intersection and determine its value for some classes of graphs.
Źródło:
Opuscula Mathematica; 2023, 43, 6; 813-827
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Edge Dominating Sets and Vertex Covers
Autorzy:
Dutton, Ronald
Klostermeyer, William F.
Powiązania:
https://bibliotekanauki.pl/articles/30146532.pdf
Data publikacji:
2013-05-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
edge dominating set
matching
total dominating set
vertex cover
Opis:
Bipartite graphs with equal edge domination number and maximum matching cardinality are characterized. These two parameters are used to develop bounds on the vertex cover and total vertex cover numbers of graphs and a resulting chain of vertex covering, edge domination, and matching parameters is explored. In addition, the total vertex cover number is compared to the total domination number of trees and grid graphs.
Źródło:
Discussiones Mathematicae Graph Theory; 2013, 33, 2; 437-456
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dominating Vertex Covers: The Vertex-Edge Domination Problem
Autorzy:
Klostermeyer, William F.
Messinger, Margaret-Ellen
Yeo, Anders
Powiązania:
https://bibliotekanauki.pl/articles/32083812.pdf
Data publikacji:
2021-02-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
cubic graph
dominating set
vertex cover
vertex-edge dominating set
Opis:
The vertex-edge domination number of a graph, γve(G), is defined to be the cardinality of a smallest set D such that there exists a vertex cover C of G such that each vertex in C is dominated by a vertex in D. This is motivated by the problem of determining how many guards are needed in a graph so that a searchlight can be shone down each edge by a guard either incident to that edge or at most distance one from a vertex incident to the edge. Our main result is that for any cubic graph G with n vertices, γve(G) ≤ 9n/26. We also show that it is NP-hard to decide if γve(G) = γ(G) for bipartite graph G.
Źródło:
Discussiones Mathematicae Graph Theory; 2021, 41, 1; 123-132
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A characterization of roman trees
Autorzy:
Henning, Michael
Powiązania:
https://bibliotekanauki.pl/articles/743366.pdf
Data publikacji:
2002
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
dominating set
Roman dominating function
Opis:
A Roman dominating function (RDF) on a graph G = (V,E) is a function f: V → {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. The weight of f is $w(f) = ∑_{v ∈ V} f(v)$. The Roman domination number is the minimum weight of an RDF in G. It is known that for every graph G, the Roman domination number of G is bounded above by twice its domination number. Graphs which have Roman domination number equal to twice their domination number are called Roman graphs. At the Ninth Quadrennial International Conference on Graph Theory, Combinatorics, Algorithms, and Applications held at Western Michigan University in June 2000, Stephen T. Hedetniemi in his principal talk entitled "Defending the Roman Empire" posed the open problem of characterizing the Roman trees. In this paper, we give a characterization of Roman trees.
Źródło:
Discussiones Mathematicae Graph Theory; 2002, 22, 2; 325-334
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Bounds on the Locating-Total Domination Number in Trees
Autorzy:
Wang, Kun
Ning, Wenjie
Lu, Mei
Powiązania:
https://bibliotekanauki.pl/articles/31867549.pdf
Data publikacji:
2020-02-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
tree
total dominating set
locating-total dominating set
locating-total domination number
Opis:
Given a graph $G = (V, E)$ with no isolated vertex, a subset $S$ of $V$ is called a total dominating set of $G$ if every vertex in $V$ has a neighbor in $S$. A total dominating set $S$ is called a locating-total dominating set if for each pair of distinct vertices $u$ and $v$ in $V \ S, N(u) ∩ S ≠ N(v) ∩ S$. The minimum cardinality of a locating-total dominating set of $G$ is the locating-total domination number, denoted by $γ_t^L(G)$. We show that, for a tree $T$ of order $n ≥ 3$ and diameter $d$, \(\frac{d+1}{2}≤γ_t^L(T)≤n−\frac{d−1}{2}\), and if $T$ has $l$ leaves, $s$ support vertices and $s_1$ strong support vertices, then \(γ_t^L(T)≥max\Big\{\frac{n+l−s+1}{2}−\frac{s+s_1}{4},\frac{2(n+1)+3(l−s)−s_1}{5}\Big\}\). We also characterize the extremal trees achieving these bounds.
Źródło:
Discussiones Mathematicae Graph Theory; 2020, 40, 1; 25-34
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
False alarms in fault-tolerant dominating sets in graphs
Autorzy:
Nikodem, M.
Powiązania:
https://bibliotekanauki.pl/articles/255949.pdf
Data publikacji:
2012
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
liar’s dominating set
fault-tolerant dominating set
false alarm
hamming distance
Opis:
We develop the problem of fault-tolerant dominating sets (liar's dominating sets) in graphs. Namely, we consider a new kind of fault - a false alarm. Characterization of such fault-tolerant dominating sets in three different cases (dependent on the classification of the types of the faults) are presented.
Źródło:
Opuscula Mathematica; 2012, 32, 4; 751-760
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mean value for the matching and dominating polynomial
Autorzy:
Arocha, Jorge
Llano, Bernardo
Powiązania:
https://bibliotekanauki.pl/articles/743687.pdf
Data publikacji:
2000
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
matching
matching polynomial
dominating set
Opis:
The mean value of the matching polynomial is computed in the family of all labeled graphs with n vertices. We introduce the dominating polynomial of a graph whose coefficients enumerate the dominating sets for a graph and study some properties of the polynomial. The mean value of this polynomial is determined in a certain special family of bipartite digraphs.
Źródło:
Discussiones Mathematicae Graph Theory; 2000, 20, 1; 57-69
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Domination hypergraphs of certain digraphs
Autorzy:
Sonntag, M.
Teichert, H. M.
Powiązania:
https://bibliotekanauki.pl/articles/254767.pdf
Data publikacji:
2010
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
hypergraph
dominating set
directed graph
Opis:
If D = (V,A) is a digraph, its domination hypergraph DH(D) = (V, E) has the vertex set V and e ⊆ V is an edge of DH(D) if and only if e is a minimal dominating set of D. We investigate domination hypergraphs of special classes of digraphs, namely tournaments, paths and cycles. Finally, using a special decomposition/composition method we construct edge sets of domination hypergraphs of certain digraphs.
Źródło:
Opuscula Mathematica; 2010, 30, 2; 179-191
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On non-z(mod k) dominating sets
Autorzy:
Caro, Yair
Jacobson, Michael
Powiązania:
https://bibliotekanauki.pl/articles/743399.pdf
Data publikacji:
2003
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
dominating set
tree
unicyclic graph
Opis:
For a graph G, a positive integer k, k ≥ 2, and a non-negative integer with z < k and z ≠ 1, a subset D of the vertex set V(G) is said to be a non-z (mod k) dominating set if D is a dominating set and for all x ∈ V(G), |N[x]∩D| ≢ z (mod k).For the case k = 2 and z = 0, it has been shown that these sets exist for all graphs. The problem for k ≥ 3 is unknown (the existence for even values of k and z = 0 follows from the k = 2 case.) It is the purpose of this paper to show that for k ≥ 3 and with z < k and z ≠ 1, that a non-z(mod k) dominating set exist for all trees. Also, it will be shown that for k ≥ 4, z ≥ 1, 2 or 3 that any unicyclic graph contains a non-z(mod k) dominating set. We also give a few special cases of other families of graphs for which these dominating sets must exist.
Źródło:
Discussiones Mathematicae Graph Theory; 2003, 23, 1; 189-199
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Highly connected counterexamples to a conjecture on α-domination
Autorzy:
Tuza, Zsolt
Powiązania:
https://bibliotekanauki.pl/articles/744177.pdf
Data publikacji:
2005
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
graph
dominating set
α-domination
Opis:
An infinite class of counterexamples is given to a conjecture of Dahme et al. [1] concerning the minimum size of a dominating vertex set that contains at least a prescribed proportion of the neighbors of each vertex not belonging to the set.
Źródło:
Discussiones Mathematicae Graph Theory; 2005, 25, 3; 435-440
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
NP-completeness of weakly convex and convex dominating set decision problems
Autorzy:
Raczek, J.
Powiązania:
https://bibliotekanauki.pl/articles/2050778.pdf
Data publikacji:
2004
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
dominating set
NP-completeness
distance
convex set
Opis:
The convex domination number and the weakly convex domination number are new domination parameters. In this paper we show that the decision problems of convex and weakly convex dominating sets are NP-complete for bipartite and split graphs. Using a modified version of Warshall algorithm we can verify in polynomial time whether a given subset of vertices of a graph is convex or weakly convex.
Źródło:
Opuscula Mathematica; 2004, 24, 2; 189-196
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The domination number of $K_n^3$
Autorzy:
Georges, John
Lin, Jianwei
Mauro, David
Powiązania:
https://bibliotekanauki.pl/articles/30148694.pdf
Data publikacji:
2014-08-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
Cartesian product
dominating set
domination number
Opis:
Let $K_n^3$ denote the Cartesian product $K_n□K_n□K_n$, where $K_n$ is the complete graph on $n$ vertices. We show that the domination number of $K_n^3$ is $⌈\frac{n^2}{2}⌉$.
Źródło:
Discussiones Mathematicae Graph Theory; 2014, 34, 3; 629-632
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
M2-edge colorings of dense graphs
Autorzy:
Ivanco, J.
Powiązania:
https://bibliotekanauki.pl/articles/254913.pdf
Data publikacji:
2016
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
edge coloring
dominating set
dense graphs
Opis:
An edge coloring φ of a graph G is called an Mi-edge coloring if [formula] every vertex v of G, where φ (v) is the set of colors of edges incident with v. Let K1(G) denote the maximum number of colors used in an Mi-edge coloring of G. In this paper we establish some bounds of K.2(G), present some graphs achieving the bounds and determine exact values of K.2(G) for dense graphs.
Źródło:
Opuscula Mathematica; 2016, 36, 5; 603-612
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Domination Number of Graphs with Minimum Degree Five
Autorzy:
Bujtás, Csilla
Powiązania:
https://bibliotekanauki.pl/articles/32222697.pdf
Data publikacji:
2021-08-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
dominating set
domination number
discharging method
Opis:
We prove that for every graph G on n vertices and with minimum degree five, the domination number γ(G) cannot exceed n/3. The proof combines an algorithmic approach and the discharging method. Using the same technique, we provide a shorter proof for the known upper bound 4n/11 on the domination number of graphs of minimum degree four.
Źródło:
Discussiones Mathematicae Graph Theory; 2021, 41, 3; 763-777
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fault Tolerant Detectors for Distinguishing Sets in Graphs
Autorzy:
Seo, Suk J.
Slater, Peter J.
Powiązania:
https://bibliotekanauki.pl/articles/31234046.pdf
Data publikacji:
2015-11-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
distinguishing sets
fault tolerant detectors
redundant distinguishing open-locating-dominating set
detection distinguishing open-locating-dominating set
Opis:
For various domination-related parameters involving locating devices (distinguishing sets) that function as places from which detectors can determine information about the location of an “intruder”, several types of possible detector faults are identified. Two of these fault tolerant detector types for distinguishing sets are considered here, namely redundant distinguishing and detection distinguishing. Illustrating these concepts, we focus primarily on open-locating-dominating sets.
Źródło:
Discussiones Mathematicae Graph Theory; 2015, 35, 4; 797-818
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On equality in an upper bound for the acyclic domination number
Autorzy:
Samodivkin, V.
Powiązania:
https://bibliotekanauki.pl/articles/255046.pdf
Data publikacji:
2008
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
dominating set
acyclic set
independent set
acyclic domination number
Opis:
A subset A of vertices in a graph G is acyclic if the subgraph it induces contains no cycles. The acyclic domination number ϒa (G) of a graph G is the minimum cardinality of an acyclic dominating set of G. For any graph G with n vertices and maximum degree Δ(G), ϒa(G) ≤ n - Δ(G). In this paper we characterize the connected graphs and the connected triangle-free graphs which achieve this upper bound.
Źródło:
Opuscula Mathematica; 2008, 28, 3; 331-334
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
γ-paired dominating graphs of cycles
Autorzy:
Eakawinrujee, Pannawat
Trakultraipruk, Nantapath
Powiązania:
https://bibliotekanauki.pl/articles/2048671.pdf
Data publikacji:
2022
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
paired dominating graph
paired dominating set
paired-domination number
Opis:
A paired dominating set of a graph G is a dominating set whose induced subgraph contains a perfect matching. The paired domination number, denoted by γpr(G), is the minimum cardinality of a paired dominating set of G. A γpr(G)-set is a paired dominating set of cardinality γpr(G). The γ-paired dominating graph of G, denoted by PDγ(G), as the graph whose vertices are γpr(G)-sets. Two γpr(G)-sets D1 and D2 are adjacent in PDγ(G) if there exists a vertex u ∈ D1 and a vertex v /∈ D1 such that D2 = (D1 \ {u}) ∪ {v}. In this paper, we present the γ-paired dominating graphs of cycles.
Źródło:
Opuscula Mathematica; 2022, 42, 1; 31-54
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dominating sets and domination polynomials of certain graphs, II
Autorzy:
Alikhani, S.
Yee-hock, P.
Powiązania:
https://bibliotekanauki.pl/articles/255942.pdf
Data publikacji:
2010
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
domination polynomial
dominating set
cycle
theta graph
Opis:
The domination polynomial of a graph G of order n is the polynomial [formula] where d(G, i) is the number of dominating sets of G of size i, and ϒ (G) is the domination number of G. In this paper, we obtain some properties of the coefficients of D(G, x). Also, by study of the dominating sets and the domination polynomials of specific graphs denoted by G'(m), we obtain a relationship between the domination polynomial of graphs containing an induced path of length at least three, and the domination polynomial of related graphs obtained by replacing the path by shorter path. As examples of graphs G' (m), we study the dominating sets and domination polynomials of cycles and generalized theta graphs. Finally, we show that, if n ≡ 0, 2(mod 3) and D(G, x) = D(Cn, x), then G = Cn.
Źródło:
Opuscula Mathematica; 2010, 30, 1; 37-51
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Domination in partitioned graphs
Autorzy:
Tuza, Zsolt
Vestergaard, Preben
Powiązania:
https://bibliotekanauki.pl/articles/743565.pdf
Data publikacji:
2002
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
graph
dominating set
domination number
vertex partition
Opis:
Let V₁, V₂ be a partition of the vertex set in a graph G, and let $γ_i$ denote the least number of vertices needed in G to dominate $V_i$. We prove that γ₁+γ₂ ≤ [4/5]|V(G)| for any graph without isolated vertices or edges, and that equality occurs precisely if G consists of disjoint 5-paths and edges between their centers. We also give upper and lower bounds on γ₁+γ₂ for graphs with minimum valency δ, and conjecture that γ₁+γ₂ ≤ [4/(δ+3)]|V(G)| for δ ≤ 5. As δ gets large, however, the largest possible value of (γ₁+γ₂)/|V(G)| is shown to grow with the order of (logδ)/(δ).
Źródło:
Discussiones Mathematicae Graph Theory; 2002, 22, 1; 199-210
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On Mf-Edge Colorings of Graphs
Autorzy:
Ivančo, Jaroslav
Onderko, Alfréd
Powiązania:
https://bibliotekanauki.pl/articles/32222570.pdf
Data publikacji:
2022-11-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
edge coloring
anti-Ramsey number
dominating set
Opis:
An edge coloring φ of a graph G is called an Mf-edge coloring if |φ(v)| ≤ f(v) for every vertex v of G, where φ(v) is the set of colors of edges incident with v and f is a function which assigns a positive integer f(v) to each vertex v. Let Kf (G) denote the maximum number of colors used in an Mf-edge coloring of G. In this paper we establish some bounds on Kf(G), present some graphs achieving the bounds and determine exact values of Kf(G) for some special classes of graphs.
Źródło:
Discussiones Mathematicae Graph Theory; 2022, 42, 4; 1075-1088
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Weakly convex and convex domination numbers
Autorzy:
Lemańska, M.
Powiązania:
https://bibliotekanauki.pl/articles/2050775.pdf
Data publikacji:
2004
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
dominating set
connected domination number
distance
isometric set
convex set
Opis:
Two new domination parameters for a connected graph G: the weakly convex domination number of G and the convex domination number of G are introduced. Relations between these parameters and the other domination parameters are derived. In particular, we study for which cubic graphs the convex domination number equals the connected domination number.
Źródło:
Opuscula Mathematica; 2004, 24, 2; 181-188
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimal Locating-Total Dominating Sets in Strips of Height 3
Autorzy:
Junnila, Ville
Powiązania:
https://bibliotekanauki.pl/articles/31339416.pdf
Data publikacji:
2015-08-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
locating-total dominating set
domination
square grid
strip
Opis:
A set C of vertices in a graph G = (V,E) is total dominating in G if all vertices of V are adjacent to a vertex of C. Furthermore, if a total dominating set C in G has the additional property that for any distinct vertices u, v ∈ V \ C the subsets formed by the vertices of C respectively adjacent to u and v are different, then we say that C is a locating-total dominating set in G. Previously, locating-total dominating sets in strips have been studied by Henning and Jafari Rad (2012). In particular, they have determined the sizes of the smallest locating-total dominating sets in the finite strips of height 2 for all lengths. Moreover, they state as open question the analogous problem for the strips of height 3. In this paper, we answer the proposed question by determining the smallest sizes of locating-total dominating sets in the finite strips of height 3 as well as the smallest density in the infinite strip of height 3.
Źródło:
Discussiones Mathematicae Graph Theory; 2015, 35, 3; 447-462
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On Minimal Geodetic Domination in Graphs
Autorzy:
Nuenay, Hearty M.
Jamil, Ferdinand P.
Powiązania:
https://bibliotekanauki.pl/articles/31339437.pdf
Data publikacji:
2015-08-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
minimal geodetic dominating set
upper geodetic domination number
Opis:
Let $G$ be a connected graph. For two vertices $u$ and $v$ in $G$, a $u$-$v$ geodesic is any shortest path joining $u$ and $v$. The closed geodetic interval $ I_G[u, v] $ consists of all vertices of $G$ lying on any $u$-$v$ geodesic. For $ S \subseteq V (G) $, $S$ is a geodetic set in $G$ if \( \bigcup_{u,v \in S} I_G [u, v] = V (G) \). Vertices $u$ and $v$ of $G$ are neighbors if $u$ and $v$ are adjacent. The closed neighborhood $ N_G[v]$ of vertex $v$ consists of $v$ and all neighbors of $v$. For $S \subseteq V (G)$, $S$ is a dominating set in $G$ if \( \bigcup_{u \in S} N_G[u] = V (G) \). A geodetic dominating set in $G$ is any geodetic set in $G$ which is at the same time a dominating set in $G$. A geodetic dominating set in $G$ is a minimal geodetic dominating set if it does not have a proper subset which is itself a geodetic dominating set in $G$. The maximum cardinality of a minimal geodetic dominating set in $G$ is the upper geodetic domination number of $G$. This paper initiates the study of minimal geodetic dominating sets and upper geodetic domination numbers of connected graphs.
Źródło:
Discussiones Mathematicae Graph Theory; 2015, 35, 3; 403-418
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Counterexample to a conjecture on the structure of bipartite partitionable graphs
Autorzy:
Gibson, Richard
Mynhardt, Christina
Powiązania:
https://bibliotekanauki.pl/articles/743437.pdf
Data publikacji:
2007
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
domination
prism fixer
symmetric dominating set
bipartite graph
Opis:
A graph G is called a prism fixer if γ(G×K₂) = γ(G), where γ(G) denotes the domination number of G. A symmetric γ-set of G is a minimum dominating set D which admits a partition D = D₁∪ D₂ such that $V(G)-N[D_i] = D_j$, i,j = 1,2, i ≠ j. It is known that G is a prism fixer if and only if G has a symmetric γ-set.
Hartnell and Rall [On dominating the Cartesian product of a graph and K₂, Discuss. Math. Graph Theory 24 (2004), 389-402] conjectured that if G is a connected, bipartite graph such that V(G) can be partitioned into symmetric γ-sets, then G ≅ C₄ or G can be obtained from $K_{2t,2t}$ by removing the edges of t vertex-disjoint 4-cycles. We construct a counterexample to this conjecture and prove an alternative result on the structure of such bipartite graphs.
Źródło:
Discussiones Mathematicae Graph Theory; 2007, 27, 3; 527-540
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Triangle-free planar graphs with minimum degree 3 have radius at least 3
Autorzy:
Kim, Seog-Jim
West, Douglas
Powiązania:
https://bibliotekanauki.pl/articles/743089.pdf
Data publikacji:
2008
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
planar graph
radius
minimum degree
triangle-free
dominating set
Opis:
We prove that every triangle-free planar graph with minimum degree 3 has radius at least 3; equivalently, no vertex neighborhood is a dominating set.
Źródło:
Discussiones Mathematicae Graph Theory; 2008, 28, 3; 563-566
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Distance 2-Domination in Prisms of Graphs
Autorzy:
Hurtado, Ferran
Mora, Mercè
Rivera-Campo, Eduardo
Zuazua, Rita
Powiązania:
https://bibliotekanauki.pl/articles/31341963.pdf
Data publikacji:
2017-05-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
distance 2 dominating set
prisms of graphs
universal fixer
Opis:
A set of vertices D of a graph G is a distance 2-dominating set of G if the distance between each vertex u ∊ (V (G) − D) and D is at most two. Let γ2(G) denote the size of a smallest distance 2-dominating set of G. For any permutation π of the vertex set of G, the prism of G with respect to π is the graph πG obtained from G and a copy G′ of G by joining u ∊ V(G) with v′ ∊ V(G′) if and only if v′ = π(u). If γ2(πG) = γ2(G) for any permutation π of V(G), then G is called a universal γ2-fixer. In this work we characterize the cycles and paths that are universal γ2-fixers.
Źródło:
Discussiones Mathematicae Graph Theory; 2017, 37, 2; 383-397
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dominating bipartite subgraphs in graphs
Autorzy:
Bacsó, Gábor
Michalak, Danuta
Tuza, Zsolt
Powiązania:
https://bibliotekanauki.pl/articles/744313.pdf
Data publikacji:
2005
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
dominating set
dominating subgraph
forbidden induced subgraph
bipartite graph
k-partite graph
Opis:
A graph G is hereditarily dominated by a class of connected graphs if each connected induced subgraph of G contains a dominating induced subgraph belonging to . In this paper we characterize graphs hereditarily dominated by classes of complete bipartite graphs, stars, connected bipartite graphs, and complete k-partite graphs.
Źródło:
Discussiones Mathematicae Graph Theory; 2005, 25, 1-2; 85-94
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Compared Costs of Domination Location-Domination and Identification
Autorzy:
Hudry, Olivier
Lobstein, Antoine
Powiązania:
https://bibliotekanauki.pl/articles/32083840.pdf
Data publikacji:
2020-02-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
graph theory
dominating set
locating-dominating code
identifying code
twin-free graph
Opis:
Let G = (V, E) be a finite graph and r ≥ 1 be an integer. For v ∈ V, let Br(v) = {x ∈ V : d(v, x) ≤ r} be the ball of radius r centered at v. A set C ⊆ V is an r-dominating code if for all v ∈ V, we have Br(v) ∩ C ≠ ∅; it is an r-locating-dominating code if for all v ∈ V, we have Br(v) ∩ C ≠ ∅, and for any two distinct non-codewords x ∈ V \ C, y ∈ V \ C, we have Br(x) ∩ C ≠ Br(y) ∩ C; it is an r-identifying code if for all v ∈ V, we have Br(v) ∩ C ≠ ∅, and for any two distinct vertices x ∈ V, y ∈ V, we have Br(x) ∩ C ≠ Br(y) ∩ C. We denote by γr(G) (respectively, ldr(G) and idr(G)) the smallest possible cardinality of an r-dominating code (respectively, an r-locating-dominating code and an r-identifying code). We study how small and how large the three differences idr(G)−ldr(G), idr(G)−γr(G) and ldr(G) − γr(G) can be.
Źródło:
Discussiones Mathematicae Graph Theory; 2020, 40, 1; 127-147
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On (k,l)-kernels in D-join of digraphs
Autorzy:
Szumny, Waldemar
Włoch, Andrzej
Włoch, Iwona
Powiązania:
https://bibliotekanauki.pl/articles/743421.pdf
Data publikacji:
2007
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
(k,l)-kernel
k-independent set
l-dominating set
D-join
counting
Opis:
In [5] the necessary and sufficient conditions for the existence of (k,l)-kernels in a D-join of digraphs were given if the digraph D is without circuits of length less than k. In this paper we generalize these results for an arbitrary digraph D. Moreover, we give the total number of (k,l)-kernels, k-independent sets and l-dominating sets in a D-join of digraphs.
Źródło:
Discussiones Mathematicae Graph Theory; 2007, 27, 3; 457-470
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Trees whose 2-domination subdivision number is 2
Autorzy:
Atapour, M.
Sheikholeslami, S. M.
Khodkar, A.
Powiązania:
https://bibliotekanauki.pl/articles/254847.pdf
Data publikacji:
2012
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
2-dominating set
2-domination number
2-domination subdivision numbe
Opis:
A set S of vertices in a graph G = (V,E) is a 2-dominating set if every vertex of V \ S is adjacent to at least two vertices of S. The 2-domination number of a graph G, denoted by γ2(G), is the minimum size of a 2-dominating set of G. The 2-domination subdivision number sdγ2 (G) is the minimum number of edges that must be subdivided (each edge in G can be subdivided at most once) in order to increase the 2-domination number. The authors have recently proved that for any tree T of order at least 3, 1 ≤ sdγ2 (T ) ≤ 2. In this paper we provide a constructive characterization of the trees whose 2-domination subdivision number is 2.
Źródło:
Opuscula Mathematica; 2012, 32, 3; 423-437
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Graph domination in distance two
Autorzy:
Bacsó, Gábor
Tálos, Attila
Tuza, Zsolt
Powiązania:
https://bibliotekanauki.pl/articles/744316.pdf
Data publikacji:
2005
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
graph
dominating set
connected domination
distance domination
forbidden induced subgraph
Opis:
Let G = (V,E) be a graph, and k ≥ 1 an integer. A subgraph D is said to be k-dominating in G if every vertex of G-D is at distance at most k from some vertex of D. For a given class of graphs, Domₖ is the set of those graphs G in which every connected induced subgraph H has some k-dominating induced subgraph D ∈ which is also connected. In our notation, Dom coincides with Dom₁. In this paper we prove that $Dom Dom _u = Dom₂ _u$ holds for $_u$ = {all connected graphs without induced $P_u$} (u ≥ 2). (In particular, ₂ = {K₁} and ₃ = {all complete graphs}.) Some negative examples are also given.
Źródło:
Discussiones Mathematicae Graph Theory; 2005, 25, 1-2; 121-128
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A simple linear algorithm for the connected domination problem in circular-arc graphs
Autorzy:
Hung, Ruo-Wei
Chang, Maw-Shang
Powiązania:
https://bibliotekanauki.pl/articles/744451.pdf
Data publikacji:
2004
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
graph algorithms
circular-arc graphs
connected dominating set
shortest path
Opis:
A connected dominating set of a graph G = (V,E) is a subset of vertices CD ⊆ V such that every vertex not in CD is adjacent to at least one vertex in CD, and the subgraph induced by CD is connected. We show that, given an arc family F with endpoints sorted, a minimum-cardinality connected dominating set of the circular-arc graph constructed from F can be computed in O(|F|) time.
Źródło:
Discussiones Mathematicae Graph Theory; 2004, 24, 1; 137-145
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the Rainbow Vertex-Connection
Autorzy:
Li, Xueliang
Shi, Yongtang
Powiązania:
https://bibliotekanauki.pl/articles/30146636.pdf
Data publikacji:
2013-05-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
rainbow vertex-connection
vertex coloring
minimum degree
2-step dominating set
Opis:
A vertex-colored graph is rainbow vertex-connected if any two vertices are connected by a path whose internal vertices have distinct colors. The rainbow vertex-connection of a connected graph $G$, denoted by $rvc(G)$, is the smallest number of colors that are needed in order to make $G$ rainbow vertex-connected. It was proved that if $G$ is a graph of order $n$ with minimum degree $ \delta $, then $ rvc(G) < 11n//\delta$. In this paper, we show that $rvc(G) \le 3n//(δ+1)+5$ for $ \delta \ge \sqrt{n-1} -1 $ and $ n \le 290 $, while $ rvc(G) \le 4n//(δ + 1) + 5 $ for $ 16 \le \delta \le \sqrt{n-1}-2 $ and $ rvc(G) \le 4n//(\delta + 1) + C(\delta) $ for $6 \le \delta \le 15$, where $ C(\delta) = e^\frac{ 3 \log (\delta^3 + 2 \delta^2 +3)-3(\log 3 - 1)}{\delta - 3} - 2$. We also prove that $ rvc(G) \le 3n//4 − 2 $ for $ \delta = 3$, $ rvc(G) \le 3n//5 − 8//5$ for $\delta = 4$ and $rvc(G) \le n//2 − 2$ for $\delta = 5$. Moreover, an example constructed by Caro et al. shows that when $ \delta \ge \sqrt{n-1} - 1 $ and $ \delta = 3, 4, 5 $, our bounds are seen to be tight up to additive constants.
Źródło:
Discussiones Mathematicae Graph Theory; 2013, 33, 2; 307-313
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spanning trees with many or few colors in edge-colored graphs
Autorzy:
Broersma, Hajo
Li, Xueliang
Powiązania:
https://bibliotekanauki.pl/articles/971955.pdf
Data publikacji:
1997
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
edge-coloring
spanning tree
matroid (intersection)
complexity
NP-complete
NP-hard
polynomial algorithm
(minimum) dominating set
Opis:
Given a graph G = (V,E) and a (not necessarily proper) edge-coloring of G, we consider the complexity of finding a spanning tree of G with as many different colors as possible, and of finding one with as few different colors as possible. We show that the first problem is equivalent to finding a common independent set of maximum cardinality in two matroids, implying that there is a polynomial algorithm. We use the minimum dominating set problem to show that the second problem is NP-hard.
Źródło:
Discussiones Mathematicae Graph Theory; 1997, 17, 2; 259-269
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An efficient connected dominating set algorithm in WSNs based on the induced tree of the crossed cube
Autorzy:
Zhang, J.
Xu, L.
Zhou, S. M.
Wu, W.
Ye, X.
Powiązania:
https://bibliotekanauki.pl/articles/330830.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
wireless sensor networks
connected dominating set
induced tree
approximation algorithm
crossed cube
bezprzewodowa sieć sensorowa
podgrafy indukowane
algorytm aproksymacyjny
Opis:
The connected dominating set (CDS) has become a well-known approach for constructing a virtual backbone in wireless sensor networks. Then traffic can forwarded by the virtual backbone and other nodes turn off their radios to save energy. Furthermore, a smaller CDS incurs fewer interference problems. However, constructing a minimum CDS is an NP-hard problem, and thus most researchers concentrate on how to derive approximate algorithms. In this paper, a novel algorithm based on the induced tree of the crossed cube (ITCC) is presented. The ITCC is to find a maximal independent set (MIS), which is based on building an induced tree of the crossed cube network, and then to connect the MIS nodes to form a CDS. The priority of an induced tree is determined according to a new parameter, the degree of the node in the square of a graph. This paper presents the proof that the ITCC generates a CDS with a lower approximation ratio. Furthermore, it is proved that the cardinality of the induced trees is a Fibonacci sequence, and an upper bound to the number of the dominating set is established. The simulations show that the algorithm provides the smallest CDS size compared with some other traditional algorithms.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2015, 25, 2; 295-309
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Quest for A Characterization of Hom-Properties of Finite Character
Autorzy:
Broere, Izak
Matsoha, Moroli D.V.
Heidema, Johannes
Powiązania:
https://bibliotekanauki.pl/articles/31340894.pdf
Data publikacji:
2016-05-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
(countable) graph
homomorphism (of graphs)
property of graphs
hom-property
(finitely-)induced-hereditary property
finitely determined property
(weakly) finite character
axiomatizable property
compactness theorems
core
connectedness
chromatic number
clique number
independence number
dominating set
Opis:
A graph property is a set of (countable) graphs. A homomorphism from a graph \( G \) to a graph \( H \) is an edge-preserving map from the vertex set of \( G \) into the vertex set of \( H \); if such a map exists, we write \( G \rightarrow H \). Given any graph \( H \), the hom-property \( \rightarrow H \) is the set of \( H \)-colourable graphs, i.e., the set of all graphs \( G \) satisfying \( G \rightarrow H \). A graph property \( mathcal{P} \) is of finite character if, whenever we have that \( F \in \mathcal{P} \) for every finite induced subgraph \( F \) of a graph \( G \), then we have that \( G \in \mathcal{P} \) too. We explore some of the relationships of the property attribute of being of finite character to other property attributes such as being finitely-induced-hereditary, being finitely determined, and being axiomatizable. We study the hom-properties of finite character, and prove some necessary and some sufficient conditions on \( H \) for \( \rightarrow H \) to be of finite character. A notable (but known) sufficient condition is that \( H \) is a finite graph, and our new model-theoretic proof of this compactness result extends from hom-properties to all axiomatizable properties. In our quest to find an intrinsic characterization of those \( H \) for which \( \rightarrow H \) is of finite character, we find an example of an infinite connected graph with no finite core and chromatic number 3 but with hom-property not of finite character.
Źródło:
Discussiones Mathematicae Graph Theory; 2016, 36, 2; 479-500
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
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