The MaxSumSum (maximum diversity) problem consists of the selection of <i>p</i> facilities among <i>n</i> candidate locations in a way that the total sum ...

Dispersion problems consist of the selection of a fixed number of vertices from a given set so that some function of the distances among the vertices is maxi...

Since the late forties of the last century, methods of operations research have been extensively used to solve problems in graph theory, and graph theory has...

The paper answers an open problem introduced by Bezdek and Fodor in 2000. The width of any unit-diameter octagon is shown to be less than or equal to `(\fra...

Using a heuristic optimization module based upon Variable Neighborhood Search (VNS), the system AutoGraphiX's main feature is to find extremal or near extre...

We introduce a signless Laplacian for the distance matrix of a connected graph, called the <i>distance signless Laplacian</i>. We study the <i>distance signl...

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...

Finding communities, or clusters, or modules, in networks can be done by optimizing an objective function defined globally and/or by specifying conditions wh...

Clusterwise regression is a clustering technique where multiple lines or hyperplanes are fit to mutually exclusive subsets of a dataset such that the sum of ...

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...

Finding communities, or clusters, in networks, or graphs, has been the subject of intense studies in the last ten years. The most used criterion for that pu...

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 objective in the continuous facility location problem with limited distances is to minimize the sum of distance functions from the facility to the cust...

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...