Metacirculants are a basic and well-studied family of vertex-transitive graphs, and weak metacirculants are generalizations of them. A graph is called a weak metacirculant if it has a vertex-transitive metacyclic automorphism group. This paper is devoted to the study of weak metacirculants with odd prime power order. We first prove that a weak metacirculant of odd prime power order is a metacir...

We give a first polynomial-time algorithm for (Weighted) Feedback Vertex Set on graphs of bounded maximum induced matching width (mim-width). Explicitly, given a branch decomposition of mim-width w, we give an nO(w)-time algorithm that solves Feedback Vertex Set. This provides a unified algorithm for many well-known classes, such as Interval graphs and Permutation graphs, and furthermore, it gi...

The objective of this paper is to investigate the effect of fuel injection pressure on power performance and fuel consumption of diesel engine. In a diesel engine, fuel injection pressure is an important aspect of the engines’ power performance in order to obtain combustion treatment. The experiments in this paper are performed on a four-cylinder two-stroke direct injection diesel engine. The d...

This paper introduces a family of modular, self-similar, small-world graphs with clustering zero. Relevant properties of this family are comparable to those of some networks associated with technological systems with a low clustering, like the power grid or some electronic circuits. Moreover, the graphs are outerplanar and it is know that many algorithms that are NP-complete for general graphs ...

The explicit construction of infinite families of d-regular graphs which are Ramanujan is known only in the case d−1 is a prime power. In this paper, we consider the case when d− 1 is not a prime power. The main result is that by perturbing known Ramanujan graphs and using results about gaps between consecutive primes, we are able to construct infinite families of “almost” Ramanujan graphs for ...

Software collaboration graphs for two Open Source software projects written in the Java programming language, the Kowari Metastore and JRDF, were analyzed for fifteen-month periods of development. Collaboration graphs were produced at the package, class and method levels. The collaboration graphs were found to form networks which exhibited approximately scale-free properties at all three levels...

The explicit construction of infinite families of d-regular graphs which are Ramanujan is known only in the case d 1 is a prime power. In this paper, we consider the case when d 1 is not a prime power. The main result is that by perturbing known Ramanujan graphs and using results about gaps between consecutive primes, we are able to construct infinite families of ‘‘almost’’ Ramanujan graphs for...

We examine powers of Hamiltonian paths and cycles as well as Hamiltonian (power) completion problems in several highly structured graph classes. For threshold graphs we give efficient algorithms as well as sufficient and minimax toughness like conditions. For arborescent comparability graphs we have similar results but also show that for one type of completion problem an ‘obvious’ minimax condi...