Jenq-Jong Lin - Academia.edu (original) (raw)

Papers by Jenq-Jong Lin

Research paper thumbnail of A characterization of unicyclic graphs with the same independent domination number

Applied Mathematical Sciences

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Research paper thumbnail of Unicyclic graphs with the total domination number twice the distance-2 domination number

Applied Mathematical Sciences

This article is distributed under the Creative Commons by-nc-nd Attribution License.

Research paper thumbnail of The 3-independence number of trees

Applied Mathematical Sciences, 2020

This article is distributed under the Creative Commons by-nc-nd Attribution License.

Research paper thumbnail of Algorithms for generating all the maximal independent sets of some graphs

International Journal of Contemporary Mathematical Sciences, 2018

An independent set is a set of vertices in a graph, no two of which are adjacent. A maximal indep... more An independent set is a set of vertices in a graph, no two of which are adjacent. A maximal independent set is an independent set that is not a proper subset of any other independent set. Note that in general counting the number of maximal independent sets in a graph is NP-complete [5]. In this paper, we give two linear-time algorithms to characterize all the maximal independent sets of the path P n and the cycle C n .

Research paper thumbnail of The second largest number of maximum independent sets in trees of odd order without duplicated leaves

Applied Mathematical Sciences, 2021

This article is distributed under the Creative Commons by-nc-nd Attribution License.

Research paper thumbnail of Domination Numbers of Trees

Proceedings of the 2017 International Conference on Applied Mathematics, Modelling and Statistics Application (AMMSA 2017), 2017

A set S of vertices is a dominating set of G if NG[S]=V(G). The domination number γ(G) of a graph... more A set S of vertices is a dominating set of G if NG[S]=V(G). The domination number γ(G) of a graph G is the minimum cardinality among all dominating sets of G. The decision problem of determining the domination number for arbitrary graphs is NP-complete. Here we focus on trees. If x and x' are duplicated leaves adjacent to the same support vertex in a tree T, then γ(Tx')= γ(T). If T' can be obtained from T by adding some duplicated leaves, we can see that γ(T')= γ(T). So the maximum order of a tree T, which is γ(T)=k, is infinity. In this paper, we focus on trees which are without duplicated leaves. For k≧1, we determine the minimum and maximum orders of the trees T which are without duplicated leaves and γ(T)=k. Moreover, we characterize the trees of minimum and maximum orders.

Research paper thumbnail of A characterization of the cactus graphs with equal domination and connected domination numbers

The International Journal of Contemporary Mathematical Sciences, 2017

A cactus graph is a connected graph in which any two cycles have at most one vertex in common. Le... more A cactus graph is a connected graph in which any two cycles have at most one vertex in common. Let γ(G) and γc(G) be the domination number and connected domination number of a graph G, respectively. We can see that γ(G) ≤ γc(G) for any graph G. S. Arumugam and J. Paulraj Joseph [1] have characterized trees, unicyclic graphs and cubic graphs with equal domination and connected domination numbers. A few years later, Xue-gang Chena, Liang Suna, Hua-ming Xing [3] characterized the cactus graphs for which the domination number is equal to the connected domination number. Their characterization is in terms of global properties of a construction. In this paper, we provide a constructive characterization of the cactus graphs with equal domination and connected domination numbers. Mathematics Subject Classification: 05C69

Research paper thumbnail of Weak-trees with equal distance-2 domination and independent domination

The distance between two vertices u and v in a graph equals the length of a shortest path from u ... more The distance between two vertices u and v in a graph equals the length of a shortest path from u to v. The distance-2 domination number of a graph G, denoted by γ2(G), is the minimum cardinality of a vertex subset where every vertex not belonging to the set is within distance two from some element of the set. The independent domination number of a graph G, denoted by γi(G), is the minimum cardinality of a vertex subset that it is an independent set and every vertex not belonging to the set is adjacent to an element of the set. A weak-tree is a tree which has no duplicated leaf. Here we focus on the weak-trees. Let T (n) be the set of weak-trees T̃ satisfying γ2(T̃ ) = γi(T̃ ) = n. In this paper, we provide a constructive characterization of T (n) for all n ≥ 2. Mathematics Subject Classification: 05C05, 05C69

Research paper thumbnail of Trees with the total domination number twice the distance-2 domination number

The International Journal of Contemporary Mathematical Sciences, 2021

The distance between two vertices u and v in a graph equals the length of a shortest path from u ... more The distance between two vertices u and v in a graph equals the length of a shortest path from u to v. The distance-2 domination number of a graph G, denoted by γ2(G), is the minimum cardinality of a vertex subset where every vertex not belonging to the set is within distance two from some element of the set. The total domination number of a graph G, denoted by γt(G), is the minimum cardinality of a vertex subset where every vertex of G is adjacent to an element of the set. For any nontrivial connected graph G, we can see that γt(G) ≥ 2. Here we focus on the trees. For n ≥ 1, let T (n) be the set of trees T satisfying γt(T ) = 2γ2(T ) = 2n. In this paper, we provide a constructive characterization of T (n) for all n ≥ 1. Mathematics Subject Classification: 05C05, 05C69

Research paper thumbnail of On the 2-independence number of connected graphs

International Journal of Contemporary Mathematical Sciences, 2020

This article is distributed under the Creative Commons by-nc-nd Attribution License.

Research paper thumbnail of On the 2-independence number of trees

International Journal of Contemporary Mathematical Sciences, 2020

This article is distributed under the Creative Commons by-nc-nd Attribution License.

Research paper thumbnail of Trees with the same distance domination number

International Journal of Contemporary Mathematical Sciences, 2020

This article is distributed under the Creative Commons by-nc-nd Attribution License.

Research paper thumbnail of {Ck, Pk, Sk} -Decompositions of Balanced Complete Bipartite Multigraphs

Open Journal of Discrete Mathematics, 2016

Let 2 0 mod λ .

Research paper thumbnail of The Number of Maximal Independent Sets in the Pm-extended of Graphs

DEStech Transactions on Computer Science and Engineering, 2020

A maximal independent set is an independent set that is not a proper subset of any other independ... more A maximal independent set is an independent set that is not a proper subset of any other independent set. Given a graph G of order n, we define the m P-extended of G, denoted G(m), as the graph consisting of G together with n copies of m P , a leaf of each path attached to exactly one vertex of G. In this paper, we determine the number of maximal independent sets of the m P-extended of a star and a path.

Research paper thumbnail of A Constructive Characterization of Trees with the Same Distance-3 Domination Number

DEStech Transactions on Computer Science and Engineering, 2020

Research paper thumbnail of Decompositions of balanced complete bipartite graphs into suns and stars

International Journal of Contemporary Mathematical Sciences, 2018

Let L = {H 1 , H 2 ,. .. , H r } be a family of subgraphs of a graph G. An L-decomposition of G i... more Let L = {H 1 , H 2 ,. .. , H r } be a family of subgraphs of a graph G. An L-decomposition of G is an edge-disjoint decomposition of G into positive integer α i copies of H i , where i ∈ {1, 2,. .. , r}. Let S(C k/2) and S k denote a sun and a star with k edges, respectively. In this paper, we prove that a balanced complete bipartite graph with 2n vertices has a {S(C k/2), S k }-decomposition if and only if 8 ≤ k ≤ n, k ≡ 0 (mod 4) and n 2 ≡ 0 (mod k).

Research paper thumbnail of The k-th largest numbers of maximum independent sets in quasi-forest graphs

International Journal of Contemporary Mathematical Sciences, 2019

This article is distributed under the Creative Commons by-nc-nd Attribution License.

Research paper thumbnail of Characterization of the distance-k independent dominating sets of the n-path

International Journal of Contemporary Mathematical Sciences, 2018

The distance between two vertices u and v in a graph G equals the length of a shortest path from ... more The distance between two vertices u and v in a graph G equals the length of a shortest path from u to v. A set I of vertices is distance-k independent if every vertex in I is at distance at least k + 1 to any other vertex of I. A set I of vertices is distance-k dominating if every vertex not belonging to I is at distance at most k of a vertex in I. A set of vertices is a distance-k independent dominating set if and only if this set is a distance-k independent set and a distance-k dominating set. Note that in general counting the number of independent dominating sets in a graph is NP-complete [2]. In this paper, we want to characterize all the distance-k independent dominating sets of the path P n. Besides, we calculate the number of the distance-k independent dominating sets of P n .

Research paper thumbnail of The Number of Maximal Independent Sets in Quasi-Tree Graphs and Quasi-Forest Graphs

Open Journal of Discrete Mathematics, 2017

A maximal independent set is an independent set that is not a proper subset of any other independ... more A maximal independent set is an independent set that is not a proper subset of any other independent set. A connected graph (respectively, graph) G with vertex set () V G is called a quasi-tree graph (respectively, quasi-forest graph), if there exists a vertex () x V G ∈ such that G x − is a tree (respectively, forest). In this paper, we survey on the large numbers of maximal independent sets among all trees, forests, quasi-trees and quasi-forests. In addition, we further look into the problem of determining the third largest number of maximal independent sets among all quasi-trees and quasi-forests. Extremal graphs achieving these values are also given.

Research paper thumbnail of Quasi-forest graphs with the k-th largest number of maximal independent sets

International Journal of Contemporary Mathematical Sciences, 2017

In this paper we complete the determination of the k-th (3 ≤ k ≤ n−1 2) largest numbers of maxima... more In this paper we complete the determination of the k-th (3 ≤ k ≤ n−1 2) largest numbers of maximal independent sets among all quasiforest graphs of order n ≥ 8 and characterize the extremal graphs.

Research paper thumbnail of A characterization of unicyclic graphs with the same independent domination number

Applied Mathematical Sciences

This article is distributed under the Creative Commons by-nc-nd Attribution License.

Research paper thumbnail of Unicyclic graphs with the total domination number twice the distance-2 domination number

Applied Mathematical Sciences

This article is distributed under the Creative Commons by-nc-nd Attribution License.

Research paper thumbnail of The 3-independence number of trees

Applied Mathematical Sciences, 2020

This article is distributed under the Creative Commons by-nc-nd Attribution License.

Research paper thumbnail of Algorithms for generating all the maximal independent sets of some graphs

International Journal of Contemporary Mathematical Sciences, 2018

An independent set is a set of vertices in a graph, no two of which are adjacent. A maximal indep... more An independent set is a set of vertices in a graph, no two of which are adjacent. A maximal independent set is an independent set that is not a proper subset of any other independent set. Note that in general counting the number of maximal independent sets in a graph is NP-complete [5]. In this paper, we give two linear-time algorithms to characterize all the maximal independent sets of the path P n and the cycle C n .

Research paper thumbnail of The second largest number of maximum independent sets in trees of odd order without duplicated leaves

Applied Mathematical Sciences, 2021

This article is distributed under the Creative Commons by-nc-nd Attribution License.

Research paper thumbnail of Domination Numbers of Trees

Proceedings of the 2017 International Conference on Applied Mathematics, Modelling and Statistics Application (AMMSA 2017), 2017

A set S of vertices is a dominating set of G if NG[S]=V(G). The domination number γ(G) of a graph... more A set S of vertices is a dominating set of G if NG[S]=V(G). The domination number γ(G) of a graph G is the minimum cardinality among all dominating sets of G. The decision problem of determining the domination number for arbitrary graphs is NP-complete. Here we focus on trees. If x and x' are duplicated leaves adjacent to the same support vertex in a tree T, then γ(Tx')= γ(T). If T' can be obtained from T by adding some duplicated leaves, we can see that γ(T')= γ(T). So the maximum order of a tree T, which is γ(T)=k, is infinity. In this paper, we focus on trees which are without duplicated leaves. For k≧1, we determine the minimum and maximum orders of the trees T which are without duplicated leaves and γ(T)=k. Moreover, we characterize the trees of minimum and maximum orders.

Research paper thumbnail of A characterization of the cactus graphs with equal domination and connected domination numbers

The International Journal of Contemporary Mathematical Sciences, 2017

A cactus graph is a connected graph in which any two cycles have at most one vertex in common. Le... more A cactus graph is a connected graph in which any two cycles have at most one vertex in common. Let γ(G) and γc(G) be the domination number and connected domination number of a graph G, respectively. We can see that γ(G) ≤ γc(G) for any graph G. S. Arumugam and J. Paulraj Joseph [1] have characterized trees, unicyclic graphs and cubic graphs with equal domination and connected domination numbers. A few years later, Xue-gang Chena, Liang Suna, Hua-ming Xing [3] characterized the cactus graphs for which the domination number is equal to the connected domination number. Their characterization is in terms of global properties of a construction. In this paper, we provide a constructive characterization of the cactus graphs with equal domination and connected domination numbers. Mathematics Subject Classification: 05C69

Research paper thumbnail of Weak-trees with equal distance-2 domination and independent domination

The distance between two vertices u and v in a graph equals the length of a shortest path from u ... more The distance between two vertices u and v in a graph equals the length of a shortest path from u to v. The distance-2 domination number of a graph G, denoted by γ2(G), is the minimum cardinality of a vertex subset where every vertex not belonging to the set is within distance two from some element of the set. The independent domination number of a graph G, denoted by γi(G), is the minimum cardinality of a vertex subset that it is an independent set and every vertex not belonging to the set is adjacent to an element of the set. A weak-tree is a tree which has no duplicated leaf. Here we focus on the weak-trees. Let T (n) be the set of weak-trees T̃ satisfying γ2(T̃ ) = γi(T̃ ) = n. In this paper, we provide a constructive characterization of T (n) for all n ≥ 2. Mathematics Subject Classification: 05C05, 05C69

Research paper thumbnail of Trees with the total domination number twice the distance-2 domination number

The International Journal of Contemporary Mathematical Sciences, 2021

The distance between two vertices u and v in a graph equals the length of a shortest path from u ... more The distance between two vertices u and v in a graph equals the length of a shortest path from u to v. The distance-2 domination number of a graph G, denoted by γ2(G), is the minimum cardinality of a vertex subset where every vertex not belonging to the set is within distance two from some element of the set. The total domination number of a graph G, denoted by γt(G), is the minimum cardinality of a vertex subset where every vertex of G is adjacent to an element of the set. For any nontrivial connected graph G, we can see that γt(G) ≥ 2. Here we focus on the trees. For n ≥ 1, let T (n) be the set of trees T satisfying γt(T ) = 2γ2(T ) = 2n. In this paper, we provide a constructive characterization of T (n) for all n ≥ 1. Mathematics Subject Classification: 05C05, 05C69

Research paper thumbnail of On the 2-independence number of connected graphs

International Journal of Contemporary Mathematical Sciences, 2020

This article is distributed under the Creative Commons by-nc-nd Attribution License.

Research paper thumbnail of On the 2-independence number of trees

International Journal of Contemporary Mathematical Sciences, 2020

This article is distributed under the Creative Commons by-nc-nd Attribution License.

Research paper thumbnail of Trees with the same distance domination number

International Journal of Contemporary Mathematical Sciences, 2020

This article is distributed under the Creative Commons by-nc-nd Attribution License.

Research paper thumbnail of {Ck, Pk, Sk} -Decompositions of Balanced Complete Bipartite Multigraphs

Open Journal of Discrete Mathematics, 2016

Let 2 0 mod λ .

Research paper thumbnail of The Number of Maximal Independent Sets in the Pm-extended of Graphs

DEStech Transactions on Computer Science and Engineering, 2020

A maximal independent set is an independent set that is not a proper subset of any other independ... more A maximal independent set is an independent set that is not a proper subset of any other independent set. Given a graph G of order n, we define the m P-extended of G, denoted G(m), as the graph consisting of G together with n copies of m P , a leaf of each path attached to exactly one vertex of G. In this paper, we determine the number of maximal independent sets of the m P-extended of a star and a path.

Research paper thumbnail of A Constructive Characterization of Trees with the Same Distance-3 Domination Number

DEStech Transactions on Computer Science and Engineering, 2020

Research paper thumbnail of Decompositions of balanced complete bipartite graphs into suns and stars

International Journal of Contemporary Mathematical Sciences, 2018

Let L = {H 1 , H 2 ,. .. , H r } be a family of subgraphs of a graph G. An L-decomposition of G i... more Let L = {H 1 , H 2 ,. .. , H r } be a family of subgraphs of a graph G. An L-decomposition of G is an edge-disjoint decomposition of G into positive integer α i copies of H i , where i ∈ {1, 2,. .. , r}. Let S(C k/2) and S k denote a sun and a star with k edges, respectively. In this paper, we prove that a balanced complete bipartite graph with 2n vertices has a {S(C k/2), S k }-decomposition if and only if 8 ≤ k ≤ n, k ≡ 0 (mod 4) and n 2 ≡ 0 (mod k).

Research paper thumbnail of The k-th largest numbers of maximum independent sets in quasi-forest graphs

International Journal of Contemporary Mathematical Sciences, 2019

This article is distributed under the Creative Commons by-nc-nd Attribution License.

Research paper thumbnail of Characterization of the distance-k independent dominating sets of the n-path

International Journal of Contemporary Mathematical Sciences, 2018

The distance between two vertices u and v in a graph G equals the length of a shortest path from ... more The distance between two vertices u and v in a graph G equals the length of a shortest path from u to v. A set I of vertices is distance-k independent if every vertex in I is at distance at least k + 1 to any other vertex of I. A set I of vertices is distance-k dominating if every vertex not belonging to I is at distance at most k of a vertex in I. A set of vertices is a distance-k independent dominating set if and only if this set is a distance-k independent set and a distance-k dominating set. Note that in general counting the number of independent dominating sets in a graph is NP-complete [2]. In this paper, we want to characterize all the distance-k independent dominating sets of the path P n. Besides, we calculate the number of the distance-k independent dominating sets of P n .

Research paper thumbnail of The Number of Maximal Independent Sets in Quasi-Tree Graphs and Quasi-Forest Graphs

Open Journal of Discrete Mathematics, 2017

A maximal independent set is an independent set that is not a proper subset of any other independ... more A maximal independent set is an independent set that is not a proper subset of any other independent set. A connected graph (respectively, graph) G with vertex set () V G is called a quasi-tree graph (respectively, quasi-forest graph), if there exists a vertex () x V G ∈ such that G x − is a tree (respectively, forest). In this paper, we survey on the large numbers of maximal independent sets among all trees, forests, quasi-trees and quasi-forests. In addition, we further look into the problem of determining the third largest number of maximal independent sets among all quasi-trees and quasi-forests. Extremal graphs achieving these values are also given.

Research paper thumbnail of Quasi-forest graphs with the k-th largest number of maximal independent sets

International Journal of Contemporary Mathematical Sciences, 2017

In this paper we complete the determination of the k-th (3 ≤ k ≤ n−1 2) largest numbers of maxima... more In this paper we complete the determination of the k-th (3 ≤ k ≤ n−1 2) largest numbers of maximal independent sets among all quasiforest graphs of order n ≥ 8 and characterize the extremal graphs.