On the first of March 2012, Joan Gimbert, an excellent colleague and mathematician, passed away at the age of 49 years. His research is devoted to Graph Theory making important contributions mainly focused on the degree/diameter problem and other distance related problems on graphs.

a special class of cubic graphs are the cycle permutation graphs. a cycle permutation graph pn(α) is defined by taking two vertex-disjoint cycles on n vertices and adding a matching between the vertices of the two cycles.in this paper we determine a good upper bound for tenacity of cycle permutation graphs.

the total version of geometric–arithmetic index of graphs is introduced based on the endvertexdegrees of edges of their total graphs. in this paper, beside of computing the total gaindex for some graphs, its some properties especially lower and upper bounds are obtained.

As if following the natural course of an ingested particle, several structures in the gastrointestinal tract which were named after their discoverers are presented including concise backgrounds of these pioneers of the human intestines.

In this paper we present and analyze new sequential and parallel heuristics to approximate the Minimum Linear Arrangement problem (MinLA). The heuristics consist in obtaining a first global solution using Spectral Sequencing and improving it locally through Simulated Annealing. In order to accelerate the annealing process, we present a special neighborhood distribution that tends to favor moves...

Detecting strongly connected components (SCCs) in a directed graph is a fundamental graph analysis algorithm that is used in many science and engineering domains. Traditional approaches in parallel SCC detection, however, show limited performance and poor scaling behavior when applied to large real-world graph instances. In this paper, we investigate the shortcomings of the conventional approac...

We explore the clearing problem in the barter exchange market. The problem, described in the terminology of graph theory, is to find a set of vertexdisjoint, length-restricted cycles that maximize the total weight in a weighted digraph. The problem has previously been shown to be NP-HARD. We advance the understanding of this problem by the following contributions. We prove three constant inappr...