Let <i>G</i> be a connected graph of order <i>n</i>. The algebraic connectivity of <i>G</i> is the second smallest eigenvalue of the Laplacian matrix of <i>G...

The <i>proximity</i> <img src="/cgi-bin/mimetex.cgi?\pi = \pi (G)"> of a connected graph <i>G</i> is the minimum, over all vertices, of the average distance ...

We address the problem of locating in the plane objects such as segments, arcs of circumferences, arbitrary convex sets, their complements or their boundarie...

Harmonic means clustering is a variant of Minimum sum of squares clustering (which is sometimes called <i>K</i>-means clustering), designed to alleviate the ...

Variable neighborhood search (VNS) is a metaheuristic for solving combinatorial and global optimization problems whose basic idea is a systematic change o...

Let <i>Q = D + A</i> denote the signless Laplacian matrix of a graph <i>G</i> of order <i>n</i>, where <i>D</i> is the diagonal matrix of the degrees and <i...

Khalifeh, Yousefi-Azari, Ashrafi and Wagner [European J. Combin. 30 (2009) 1149-1163] conjectured that for a connected graph <i>G</i> on <i>n</i> vertices...

The proximity <img src="/cgi-bin/mimetex.cgi?\pi"> of a graph <i>G</i> is the minimum average distance from a vertex of <i>G</i> to all others. Similarly, th...

During the last three decades, the computer has been widely used in spectral graph theory. Many results about graph eigenvalues were first conjectured, and i...

This paper focuses on the use of different memory strategies to improve multistart methods. A network design problem in which the costs are given by discrete...

It is observed that mutations in the formulations of test problems over time are not infrequent. Ensuing problems are illustrated with examples from geometri...

Finding maximum likelihood parameter values for Finite Mixture Model (FMM) is often done with the Expectation Maximization (EM) algorithm. However the choice...

Frequency hopping is a feature in GSM (Global System for Mobile Communications) cellular systems in which a frequency carrying the communication rapidly chan...

This paper proposes a construction heuristic and an adaptive large neighborhood search heuristic for the technician and task scheduling problem arising in a ...

The aim of this paper is to propose a model for the design of a robust rapid transit network. In this paper, a network is said to be robust when the effect o...

Upper bounds on the average distance \(\overline{l}\) between pairs of vertices of a connected graph with given order \(n\) and minimum degree `(\delta...

The transmission of a vertex in a connected graph is the sum of all distance from that vertex to the others. It is said to be normalized if divided by <i>n-1...

Variable neighborhood search (VNS) is a metaheuristic, or framework for building heuristics, based upon systematic change of neighborhoods both in a decent ...

With the help of the Graffiti system, Fajtlowicz conjectured around 1992 that the average distance between two vertices of a connected graph <i>G</i> is at ...

Methods, models, heuristic and exact algorithms for clustering are reviewed from a mathematical programming view point.