Let N denote the set of positive integers. The sum graph G^+(S) of a finite subset S belong to N is the graph (S, E) with uv ∈ E if and only if u + v ∈ S. A graph G is said to be a sum graph if it is isomorph...Let N denote the set of positive integers. The sum graph G^+(S) of a finite subset S belong to N is the graph (S, E) with uv ∈ E if and only if u + v ∈ S. A graph G is said to be a sum graph if it is isomorphic to the sum graph of some S belong to N. By using the set Z of all integers instead of N, we obtain the definition of the integral sum graph. A graph G = (V, E) is a mod sum graph if there exists a positive integer z and a labelling, λ, of the vertices of G with distinct elements from {0, 1, 2,..., z - 1} so that uv ∈ E if and only if the sum, modulo z, of the labels assigned to u and v is the label of a vertex of G. In this paper, we prove that flower tree is integral sum graph. We prove that Dutch m-wind-mill (Dm) is integral sum graph and mod sum graph, and give the sum number of Dm.展开更多
Let G be a simple graph. The cyclic bandwidth sum problem is to determine a labeling of graph G in a cycle such that the total length of edges is as small as possible. In this paper, some upper and lower bound...Let G be a simple graph. The cyclic bandwidth sum problem is to determine a labeling of graph G in a cycle such that the total length of edges is as small as possible. In this paper, some upper and lower bounds on cyclic bandwidth sum of graphs are studied.展开更多
We introduce Tribonacci cordial labeling as an extension of Fibonacci cordial labeling, a well-known form of vertex-labelings. A graph that admits Tribonacci cordial labeling is called Tribonacci cordial graph. In thi...We introduce Tribonacci cordial labeling as an extension of Fibonacci cordial labeling, a well-known form of vertex-labelings. A graph that admits Tribonacci cordial labeling is called Tribonacci cordial graph. In this paper we investigate whether some well-known graphs are Tribonacci cordial.展开更多
文摘Let N denote the set of positive integers. The sum graph G^+(S) of a finite subset S belong to N is the graph (S, E) with uv ∈ E if and only if u + v ∈ S. A graph G is said to be a sum graph if it is isomorphic to the sum graph of some S belong to N. By using the set Z of all integers instead of N, we obtain the definition of the integral sum graph. A graph G = (V, E) is a mod sum graph if there exists a positive integer z and a labelling, λ, of the vertices of G with distinct elements from {0, 1, 2,..., z - 1} so that uv ∈ E if and only if the sum, modulo z, of the labels assigned to u and v is the label of a vertex of G. In this paper, we prove that flower tree is integral sum graph. We prove that Dutch m-wind-mill (Dm) is integral sum graph and mod sum graph, and give the sum number of Dm.
文摘Let G be a simple graph. The cyclic bandwidth sum problem is to determine a labeling of graph G in a cycle such that the total length of edges is as small as possible. In this paper, some upper and lower bounds on cyclic bandwidth sum of graphs are studied.
文摘We introduce Tribonacci cordial labeling as an extension of Fibonacci cordial labeling, a well-known form of vertex-labelings. A graph that admits Tribonacci cordial labeling is called Tribonacci cordial graph. In this paper we investigate whether some well-known graphs are Tribonacci cordial.