altan derivatives of polycyclic conjugated hydrocarbons were recently introduced and studied in theoretical organic chemistry. we now provide a generalization of the altan concept, applicable to any graph. several earlier noticed topological properties of altan derivatives of polycyclic conjugated hydrocarbons are shown to be the properties of all altan derivatives of all graphs. among these ar...

Biometric based techniques have emerged as the most promising option for recognizing individuals in recent years, for authenticating people and granting them access. Face recognition provide a biometric based authentication, authorization, surveillance services. Face recognition has gained increasing interest in the recent decade. Over the years there have been several techniques being develope...

An analog circuit synthesis method based on evolutionary circuit techniques is proposed where the chromosome in the genetic algorithm is coded through the use of adjacency matrices. The method assumes that the circuit is described at the behavioral level in order to reduce the simulation time. It is shown that adjacency matrices coding of the chromosome reduces considerably the number of anomal...

In this paper‎, ‎we define two $n$-square upper Hessenberg matrices one of which corresponds to the adjacency matrix of a directed pseudo graph‎. ‎We investigate relations between permanents and determinants of these upper Hessenberg matrices‎, ‎and sum formulas of the well-known Pell and Jacobsthal sequences‎. ‎Finally‎, ‎we present two Maple 13 procedures in order to calculate permanents of t...

In this paper we prove that a vertex-centered automorphism of a tree gives a proper factor of the characteristic polynomial of its distance or adjacency matrix. We also show that the characteristic polynomial of the distance matrix of any graph always has a factor of degree equal to the number of vertex orbits of the graph. These results are applied to full k-ary trees and some other problems. ...

Generation of realistic topologies plays an important role in determining the accuracy and validity of simulation studies. This study presents a discussion to justify why, and how often randomly generated adjacency matrices may not not conform to wireless topologies in the physical world. Specifically, it shows through analysis and random trials that, more than 90% of times, a randomly generate...

Let T be a tree, A its adjacency matrix, and a scalar. We describe a linear-time algorithm for reducing the matrix In +A. Applications include computing the rank of A, nding a maximum matching in T , computing the rank and determinant of the associated neighborhood matrix, and computing the characteristic polynomial of A.

Let G be a graph of order n. The second stage adjacency matrix of G is the symmetric n× n matrix for which the ij entry is 1 if the vertices vi and vj are of distance two; otherwise 0. The sum of the absolute values of this second stage adjacency matrix is called the second stage energy of G. In this paper we investigate a few properties and determine some upper bounds for the largest eigenvalu...