We consider the NP-hard problem of scheduling n jobs in m two-stage parallel flow shops so as to minimize the makespan. This problem decomposes into two subproblems: assigning the jobs to parallel flow shops; and scheduling the jobs assigned to the same flow shop by use of Johnson’s rule. For...

We analyze the performance of the greedy algorithm for the on-line two-machine open shop scheduling problem of minimizing makespan, in which time lags exist between the completion time of the first and the start time of the second operation of any job. The competitive ratio for the greedy...

Mathematical programming representation has been recently used to describe the behavior of discrete event systems as well as their formal properties. This new way of representing discrete event systems paves the way to the creation of simpler mathematical programming models that reduce the...

In this paper, we propose a tool for testing the quality of heuristic solutions for scheduling problems with a min-max objective function, such as, for example, the minimization of maximum tardiness or makespan. We present a bounding scheme which is powerful enough to allow an accurate quality...

The g-index is a well-known index for measuring and comparing the output of scientific researchers, which has been introduced by Leo Egghe in 2006 as an improvement of the Hirsch-index. This article gives an axiomatic characterization of the g-index in terms of three natural axioms.

We provide a new axiomatic characterization of the Hirsch-index. This new characterization is based on a simple and appealing symmetry axiom which essentially imposes that the number of citations and the number of publications should be treated in the same way and should be measured in the same...

In this note we investigate the computational complexity of the transportation problem with a permutable demand vector, TP-PD for short. In the TP-PD, the goal is to permute the elements of the given integer demand vector b=(b 1 ,…,b n ) in order to minimize the overall transportation costs....

In a recent paper, Chambers and Miller introduced two fundamental axioms for scientific research indices. We perform a detailed analysis of these two axioms, thereby providing clean combinatorial characterizations of the research indices that satisfy these axioms and of the so-called step-based...