نتایج جستجو برای: wiener index w

تعداد نتایج: 594664  

2006
Weigen Yan Yeong-Nan Yeh

Let T be an acyclic molecule with n vertices, and let S(T ) be the acyclic molecule obtained from T by replacing each edge of T by a path of length two. In this work, we show that the Wiener index of T can be explained as the number of matchings with n− 2 edges in S(T ). Furthermore, some related results are also obtained.

Ante Graovac, Franco Cataldo, Ottorino Ori, Tomislav Doslic,

We present explicit formulae for the eccentric connectivity index and Wiener index of 2-dimensional square and comb lattices with open ends. The formulae for these indices of 2-dimensional square lattices with ends closed at themselves are also derived. The index for closed ends case divided by the same index for open ends case in the limit N →&infin defines a novel quantity we call compression...

Journal: :Discrete Applied Mathematics 1997
Wen-Chung Huang Bo-Yin Yang Yeong-Nan Yeh

An explicit, non-recursive formula for the Wiener index of any given benzenoid chain is derived, greatly speeding up calculations and rendering it manually manageable, through a novel envisioning of chains as ternary strings. Previous results are encompassed and two completely new and useful ones are obtained, a formula to determine Wiener indices of benzenoid chains in periodic patterns, and a...

Journal: :Eur. J. Comb. 2009
M. H. Khalifeh Hassan Yousefi-Azari Ali Reza Ashrafi Stephan G. Wagner

We study distance-based graph invariants, such as the Wiener index, the Szeged index, and variants of these two. Relations between the various indices for trees are provided as well as formulas for line graphs and product graphs. This allows us, for instance, to establish formulas for the edge Wiener index of Hamming graphs, C4nanotubes and C4-nanotori. We also determine minimum and maximum of ...

F. WEI Y. WU Z. JIA

Let G be a simple connected graph. The generalized polarity Wiener index of G is defined as the number of unordered pairs of vertices of G whose distance is k. Some formulas are obtained for computing the generalized polarity Wiener index of the Cartesian product and the tensor product of graphs in this article.

H. YONG WANG I. GUTMAN J. QIN

The Wiener index is the sum of distances between all pairs of vertices in a connected graph. In this paper, explicit expressions for the expected value of the Wiener index of three types of random pentagonal chains (cf. Figure 1) are obtained.

The sum of distances between all the pairs of vertices in a connected graph is known as the {it Wiener index} of the graph. In this paper, we obtain the Wiener index of edge complements of stars, complete subgraphs and cycles in $K_n$.

Journal: :iranian journal of mathematical chemistry 2012
p. manuel m. arockiaraj

a lot of research and various techniques have been devoted for finding the topologicaldescriptor wiener index, but most of them deal with only particular cases. there exist threeregular plane tessellations, composed of the same kind of regular polygons namely triangular,square, and hexagonal. using edge congestion-sum problem, we devise a method to computethe wiener index and demonstrate this m...

2004
Sandi Klavžar

Abstract. A subgraph H of a graph G is gated if for every x ∈ V (G) there exists a vertex u in H such that dG(x, v) = dG(x, u) + dG(u, v) for any v ∈ V (H). The gated amalgam of graphs G1 and G2 is obtained from G1 and G2 by identifying their isomorphic gated subgraphs H1 and H2. Two theorems on the Wiener index of gated amalgams are proved. Several known results on the Wiener index of (chemica...

Journal: :Applied Mathematics and Computation 2022

The Wiener index of a graph W(G) is well studied topological for graphs. An outstanding problem Šoltés to find graphs G such that W(G)=W(G−v) all vertices v∈V(G), with the only known example being G=C11. We relax this by defining notion indices signed graphs, which we denote Wσ(G), and under relaxation construct many Wσ(G)=Wσ(G−v) v∈V(G). This ends up related independent interest, asks when it ...

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