Editorial from the Editor-in-Chief regarding this case of plagiarism

Philippe Mahey

1 Introduction

Plagiarism is a plague that any scientific publication in any discipline should fight and eradicate all over the world. Unfortunately, if, on the one hand, the powerful search engines available on the web have helped referees to identify most of the cases, the increasing number of publications have on the other hand facilitated that dubious practice and the number of cases have increased. The case we are facing today in our journal is a severe one as the "authors" are multi-recidivists who have been identified in former plagiarized papers since 2007. M. Sreenivas and T. Srinivas have this time succeeded in obtaining the publication of a plagiarized paper in the last issue of the RAIRO journal, but their fraud has been identified very quickly by different colleagues. We will briefly recall below the history of former cases involving these two persons and expose the proofs of plagiarism about the current paper which justify its retraction from the records of the journal.

2 A history of frauds

At least four papers co-authored by Sreenivas and Srinivas have been revealed in the last two years and a report about this investigation has been published on the web page of SIAM (http://www.siam.org/journals/plagiary/index.php). The method was nearly always the same as these papers contained entire paragraphs and abstracts copied almost verbatim from preprints or old papers in the field (the Transportation area). We will only resume one of these facts which is particularly instructive: as mentioned in the SIAM report, the paper: M. Sreenivas and T. Srinivas, The transportation: more-for-less criterion, International Journal of Statistics and Management System, v. 3, n. 1–2, pp. 152–165, 2008 is indeed plagiarized from S. Storøy: The transportation paradox revisited, posted to Optimization Online September 2007. Surprisingly, the same authors have submitted the same paper in parallel to the 4OR journal in october 2007, but it was discovered to be plagiarized and was not published. The editors of that journal published an editorial in the first number of the 2009 volume (D. Bouyssou, S. Martello, F. Plastria, Plagiarism again: Sreenivas and Srinivas, and an update on Marcu, 4OR vol. 7, n°1, 2009, pp. 17–20) with a transcription of the exchange mail between them and the authors where the latter did express some weak regrets without any further justification. As said in the editorial, "this did not prevent them from submitting their plagiarized text to another well-known OR journal, namely the European Journal of Operations Research" Unfortunately enough, the 4OR editorial was published too late to prevent the publication of the present paper in RAIRO.

3 The plagiarized paper

The applied procedure for this kind of plagiarism is always the same: select and copy paragraphs and sentences from textbooks or research reports, and finally merge them in a personal form that is able to mislead the reader. The following references prove that the paper "A short note on marginal analysis of a transportation problem", published in vol. 43, n°4, pp. 331–337, has been almost entirely plagiarized:

1. The entire abstract after the first sentence is a verbatim copy of a paragraph from "Deterministic modeling: linear optimization with applications", a set of course notes by Hossein Arsham.  The paragraph in question can be found at: http://home.ubalt.edu/ntsbarsh/opre640a/partVIII.htm#rmarginalFactorPri

2. The first paragraph of the introduction is taken from course notes posted by Tim Yeager at http://sorrel.humboldt.edu/%7Eeconomic/econ104/marginal/

3. The second paragraph is taken verbatim from http://www.papercamp.com/essays/Decision-Making/3884.html

4. Section 2 is a verbatim copy from K. Murty well-known textbook: http://ioe.engin.umich.edu/people/fac/books/murty/opti_model/junior-6.pdf

5. The first illustration of section 3 is taken too from Murty’s book.

6. The first paragraph of the conclusion comes from the same source as the introduction.

7. None of the references are actually referred to in the paper.

We have asked the authors of the plagiarism to explain the situation and defend themselves. Their answer was that they found normal to refer to other research papers to present the concepts. They add that "A small misunderstanding is that the sources of the taken matter are not mentioned in the article. It never repeat again". We understand in their poor defence that they plead guilty and promise to stop plagiarizing, but the long history of frauds we have reported above shows that we cannot trust them and must ban them from publishing in RAIRO.

4 Conclusion

We hope that the plagiarism activities of Sreenivas and Srinivas will now definitively stop. The above plagiarized paper will be retracted from the electronic records of the RAIRO Journal. They are now banned from publishing in an international OR journal for the second time and their former attempts are now well referenced and diffused so that the whole community, from Transportation, Operations Research and Applied Mathematics areas, will have the right tools to foil their future submissions if any.

Acknowledgements: We thank heartily the former editors of 4OR, Denis Bouyssou, Silvano Martello and Frank Plastria for identifying the plagiarism, and Douglas Arnold, President of SIAM, for his help and advice in dealing with the present plagiarism.

On étudie à l'aide du système AutoGraphiX 2 (AGX 2) des relations de la forme \[ \underline{b}_{n} \, \le \, g \, \oplus \, i \, \le \, \overline{b}_{n} \] où g désigne la maille d'un graphe G=(V, E), i un autre invariant parmi la distance moyenne $\overline{l}$, l'index λ1, l'indice de Randić R et le nombre de domination β, $\oplus$ désigne l'une des opérations +, -, ×, /, $\underline{b}_{n}$ et $\overline{b}_{n}$ des fonctions de l'ordre n du graphe qui bornent l'expression $g\oplus i$ et sont atteintes pour tout n (sauf éventuellement de très petites valeurs du fait des effets de bord). Les résultats prouvés ou discutés ci-dessous ont déjà été présentés, sous forme de conjectures, dans un article précédent paru dans RAIRO Recherche Opérationnelle [RAIRO Oper. Res. 39 (2005) 275–293].

In the paper we generalize sufficient and necessary optimality conditions obtained by Ginchev, Guerraggio, Rocca, and by authors with the help of the notion of ℓ-stability for vector functions.

In this paper, we describe the methodology used to tackle France Telecom workforce scheduling problem (the subject of the Roadef Challenge 2007) and we report the results obtained on the different data sets provided for the competition. Since the problem at hand appears to be NP-hard and due to the high dimensions of the instance sets, we use a two-step heuristical approach. We first devise a problem-tailored heuristic that provides good feasible solutions and then we use a meta-heuristic scheme to improve the current results. The tailored heuristic makes use of sophisticated integer programming models and the corresponding sub-problems are solved using CPLEX while the meta-heuristic framework is a randomized local search algorithm. The approach herein described allowed us to rank 5th in this challenge.

Le problème de planification de techniciens et d'interventions pour les télécommunications (TIST pour Technicians and Interventions Scheduling Problem for Telecommunications) comprend la planification d'interventions et l'affectation d'équipes de techniciens à ces interventions. Chaque intervention est caractérisée, entre autres, par une priorité. L'objectif de ce problème est de séquencer les interventions en tenant compte de leur priorité tout en satisfaisant un ensemble de contraintes comme l'ordre d'exécution de certaines interventions et le nombre minimum de techniciens d'un niveau de compétence donné à affecter à chaque intervention. La résolution de ce problème est centrée sur un algorithme GRASP (Greedy Randomized Adaptive Search Procedure) caractérisé par une mise à jour dynamique des critères de choix des interventions. Pour évaluer la qualité des résultats obtenus par cette approche heuristique, nous présentons également un calcul de bornes inférieures.

Linear programming techniques can be used in constructing schedules but their application is not trivial. This in particular holds true if a trade-off has to be made between computation time and solution quality. However, it turns out that – when handled with care – mixed integer linear programs may provide effective tools. This is demonstrated in the successful approach to the benchmark constructed for the 2007 ROADEF computation challenge on scheduling problems furnished by France Telecom.

Dans ce papier, nous traitons le problème de minimisation du makespan dans un flow shop hybride à deux étages avec machines dédiées. En premier lieu, nous présentons des propriétés de base, un ensemble de bornes inférieures et deux cas polynomiaux. En second lieu, nous proposons une nouvelle heuristique qui exploite ces propriétés, et cherche à placer les jobs, en tenant compte pour chaque instance du problème, de la valeur de la borne inférieure. La dernière partie de ce travail présente les résultats expérimentaux d'une étude comparative avec une heuristique de la littérature. L'analyse de ces résultats permet d'apprécier la qualité de notre proposition.

Cet article décrit une approche de la modélisation d'un système d'acteurs, particulièrement adaptée à la modélisation des entreprises, fondée sur la théorie des jeux [11] et sur l'optimisation par apprentissage du comportement de ces acteurs. Cette méthode repose sur la combinaison de trois techniques : la simulation par échantillonnage (Monte-Carlo), la théorie des jeux pour ce qui concerne la recherche d'équilibre entre les stratégies, et les méthodes heuristiques d'optimisation locale, en particulier les algorithmes génétiques. Cette combinaison n'est pas originale en soi, même si elle est rarement utilisée avec toute la puissance d'expression conjointe de ces techniques. La contribution de cet article est double : d'une part nous proposons un modèle qui permet de structurer de façon systématique cette collaboration entre différentes techniques et, d'autre part, nous utilisons la technique des algorithmes génétiques pour enrichir la recherche des équilibres de Nash sous forme de points fixes. Il s'agit d'une méthode de simulation, qui n'est pas destinée à la résolution de problèmes, mais à la validation et l'étude des propriétés d'un modèle associé à un problème particulier.

Impartial Solitaire Clobber is a one-player version of the combinatorial game Clobber, introduced by Albert et al. in 2002. The initial configuration of Impartial Solitaire Clobber is a graph, such that there is a stone placed on each of its vertex, each stone being black or white. A move of the game consists in picking a stone, and clobbering an adjacent stone of the opposite color. By clobbering we mean that the clobbered stone is removed from the graph, and replaced by the clobbering one. The aim is to make a sequence of moves leaving the minimum number of stones on the graph; this number is called the reducibility value of the configuration. As any one-player game, Solitaire Clobber is essentially an optimization problem, whose resolution may give bounds on the two-player version of the game. As an optimization problem, Solitaire Clobber can be considered as a constrained version of the underlying optimization problem related to Hamiltonian path. This enables to show that Solitaire Clobber is NP-hard. Solitaire Clobber was already studied in various graph structures, including paths, cycles, trees, and Hamming graphs. In this paper we investigate the problem in complete multipartite graphs. In particular, we give a linear-time algorithm computing the reducibility value of any configuration in complete multipartite graphs. We also address some extremal questions related to Solitaire Clobber in general graphs.