We introduce a Laplacian for the distance matrix of a connected graph, called the <i>distance Laplacian</i> and we study its spectrum. We show the equivalenc...

In 1956, Nordhaus and Gaddum gave lower and upper bounds on the sum and the product of the chromatic number of a graph and its complement, in terms of the or...

Modularity maximization is extensively used to detect communities in complex networks. It has been shown however that this method suffers from a resolution l...

We study the problem of packing equal circles in a square from the mathematical programming point of view. We discuss different formulations, we analyse fo...

In a recent paper, Zhan, Zhang, Guan, and Zhou [Phys. Rev. E <b>83</b>, 066120 (2011)] presented a modified adaptive genetic algorithm (MAGA) tailored to the...

In chemical graph theory, many graph parameters, or topological indices, were proposed as estimators of molecular structural properties. Often several varian...

It is well known that some local search algorithms for <i>K</i>-clustering problems could stop at a solution with fewer clusters than the desired <i>K</i>....

Given a graph <i>G</i> and a bipartition of its vertices, the edge-ratio is the minimum for both classes so defined of their number of internal edges divid...

The GRIEG model is a hybrid model of demo-economic projections that combines two approaches: the econometric approach - based on the micro-economy - of the N...

Community detection in networks based on modularity maximization is currently done with hierarchical divisive or agglomerative as well as with partitioning h...

Heuristics are widely applied to modularity maximization models for the identification of communities in complex networks. We present an approach to be appli...

Le but de cet article est de décrire et de résoudre un nouveau et important problème auquel font face les compagnies maritimes spécialisées dans le transport...

We present a new column generation algorithm for the determination of a classifier in the two classes LAD (Logical Analysis of Data) model. Unlike existing a...

We study extremal graphs for the extremal values of the second largest <i>Q</i>-eigenvalue of a connected graph. We first characterize all simple connected g...

Normalized cut is one of the most popular graph clustering criteria. The main approaches proposed for its resolution are spectral clustering methods (e.g. [1...

Traditionally, IP Network planning and design is mostly based on average delay or loss constraints which can often be easily calculated. Jitter, on the othe...

We present a new general variable neighborhood search approach for the uncapacitated single allocation <i>p</i>-hub median problem in networks. This NP-hard ...

The modularity maximization model proposed by Newman and Girvan for the identification of communities in networks works for general graphs possibly with loop...

A new hierarchical divisive algorithm is proposed for identifying communities in complex networks. To that effect, the definition of <i>community in the weak...

Using the AutoGraphiX system, we obtain conjectures of the form <img src="/cgi-bin/mimetex.cgi?l(n) \leq q_1 \oplus i(G)\leq u(n)"> where <img src="/cgi-bin...