#### Filter Results:

- Full text PDF available (6)

#### Publication Year

2007

2015

- This year (0)
- Last 5 years (5)
- Last 10 years (16)

#### Publication Type

#### Co-author

#### Journals and Conferences

#### Key Phrases

Learn More

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

- M. H. Khalifeh, Hassan Yousefi-Azari, Ali Reza Ashrafi
- Discrete Applied Mathematics
- 2008

The Padmakar-Ivan (PI) index of a graph G is the sum over all edges uv of G of the number of edges which are not equidistant from u and v. In this paper, the notion of vertex PI index of a graph is introduced. We apply this notion to compute an exact expression for the PI index of Cartesian product of graphs. This extends a result by Klavzar [On the PI… (More)

- Hassan Yousefi-Azari, M. H. Khalifeh, Ali Reza Ashrafi
- J. Computational Applied Mathematics
- 2011

- M. H. Khalifeh, Hassan Yousefi-Azari, Ali Reza Ashrafi
- Discrete Applied Mathematics
- 2009

- M. H. Khalifeh, Hassan Yousefi-Azari, Ali Reza Ashrafi
- Computers & Mathematics with Applications
- 2008

Let G be a graph. The distance d(u,v) between the vertices u and v of the graph G is equal to the length of a shortest path that connects u and v. The Wiener index W(G) is the sum of all distances between vertices of G, whereas the hyper-Wiener index WW(G) is defined as WW(G)=12W(G)+12@?"{"u","v"}"@?"V"("G")d (u,v)^2. In this paper the hyper-Wiener indices… (More)

- Hassan Yousefi-Azari, B. Manoochehrian, Ali Reza Ashrafi
- Appl. Math. Lett.
- 2008

The Padmakar–Ivan index of a graph G is the sum over all edges uv of G of number of edges which are not equidistant from u and v. In this work, an exact expression for the PI index of the Cartesian product of bipartite graphs is computed. Using this formula, the PI indices of C4 nanotubes and nanotori are computed. c © 2007 Elsevier Ltd. All rights reserved.

- Hassan Yousefi-Azari, B. Manoochehrian, Ali Reza Ashrafi
- Ars Comb.
- 2007

- M. H. Khalifeh, Hassan Yousefi-Azari, Ali Reza Ashrafi
- Computers & Mathematics with Applications
- 2010

- Hassan Yousefi-Azari, Ali Reza Ashrafi, N. Sedigh
- Ars Comb.
- 2009

- A. Behmaram, Hassan Yousefi-Azari, Ali Reza Ashrafi
- Appl. Math. Lett.
- 2012