There are serious issues ofresearch malpractice with the paper

J.E Rowe., M. Vose, A. Wright “State aggregation and population dynamics in linear systems” Artificial Life, Vol 11, no. 4, pages 473-492., 2005

http://www.cs.bham.ac.uk/~jer/papers/linear.pdf

which relate to plagiarism.

Below are a few aspects of malpractice. Please help us to identify more of them!

The authors claim that they are presenting a new method for state aggregation of discrete state space systems (modelling population dynamics), which are nothing else but discrete Markov chains.

The paper contains a sophisticated rewording of existing research topics and mathematical

results based on a simple, known mathematical characterisation of Markov chains. In functional

analysis, these are characterised using linear operators on the linear space of absolute state

probabilities. Consequently, the authors re-worded the Markov chains as “linear systems” and

then borrowed, without appropriate citations, topics and results from various branches of

mathematics and Markov models verification via abstraction (also reworded as aggregation or

coarse graining).

In the the pages 481-484, the authors introduce the symmetry group and the symmetry reduction method (with definitions, results and proofs) without absolutely no citation. These are concepts that have been intensively studied in algebra but which are not common background. As presented, the authors induce the idea of a new development.

There is no mention of the fact that the concepts of “state aggregation” and “lumpability” are synonyms. As expected, there is no reference regarding lumpability of Markov chains For example, people working in this area of research cite the celebrated book of John Kemeny and Laurie Snell

“Finite Markov Chains” Springer Verlag 1960 8 pages

The authors propose a method for aggregating the states of Markov chains using their associated symmetry groupsIn fact,.this method is is a plagiarised version of the very old method called “symmetry reduction of probabilistic systems”. The latest represents a very well studied method not for both the discrete stochastic processes and the continuous ones. A relevant reference is the 1990 paper of J. Glover and J. Mitro

“Symmetries and Functions of Markov Processes” The Annals of Probability 18(2): 655-668.

See also th 1982 paper of P. Hanggi, H. Thomas:

“Stochastic Processes: Time Evolution, Symmetries and Linear Response”. Physics Reports 88 (4) 207-319.

There are also uncited sources from computer science, like Prof. Peter Buchholz.Habilitation thesis from February 1996:

“A framework for the hierarchical analysis of discrete event dynamic systems” University of Dortmund.

The list below contains closely related publications that the ethical authors should have been cited. This is because in the publication context, the state aggregation is a method explicitly used in model checking and verification.

The ethical research practice asks the authors to discuss the similarities and the differences between their approach and these very closely related publications. Perhaps a deeper analysis will reveal that some papers from the uncited literature were used as source.

A. Donaldson and A. Miller, “Automatic symmetry detection for model checking using computational group theory,” in J. Fitzgerald, I. Hayes, and A. Tarlecki, Eds. “Proc. of FM 2005: Formal Methods” Springer Lecture Notes in Computer Science, vol. 3582, pp. 631–631, 2005.

E. Emerson and T. Wahl, “Dynamic symmetry reduction,” in N. Halbwachs and L. Zuck, Eds “Tools and Algorithms for the Construction and Analysis of Systems” Springer’s Lecture Notes in Computer Science, vol. 3440, pp. 382–396, 2005,

P. Buchholz. “A heuristic approach for the aggregation of Markovian submodels” In: B. Walke, O. Spaniol (eds.) Proc. MMB’93, Springer Informatik aktuell. (1993) 117-129.

E. A. Emerson and A. P. Sistla, “Symmetry and model checking,” In Formal Methods in System Design, vol. 9, pp. 105–131, 1996.

M. Kuntz and K. Lampka “Probabilistic methods in state space analysis,” in H. Hermanns, J.-P. Katoen, C. Baier, B. Haverkort, and M. Siegle, Eds. “Validation of Stochastic Systems, Springer Lecture Notes in Computer Science vol. 2925, pp. 251–266, 2004,

E. A. Emerson, J. W. Havlicek and R. J. Trefler “Virtual symmetry reduction,” Proceedings of the 15th Annual IEEE Symposium on Logic in Computer Science, pp. 121–131, 2000.

C. Norris and D. Dill “Better verification through symmetry,” Formal Methods in System Design, vol. 9, no. 1, pp. 41–75, 1996.

P. Buchholz. “Hierarchical Markovian models -symmetries and aggregation”

Performance Evaluation 22, 1995, 93-110 (Pre-version in R. Pooley, J. Hillston (eds.). Proc. Sixth International Conference on Modelling Techniques and Tools for Computer Performance Evaluation, Edinburgh University Press (1992) 305-319)

P. Buchholz. “Aggregation and reduction techniques for hierarchical GCSPNs.”

In: Proc. 5th Int. Workshop on Petri Nets and Performance Models (PNPM’93), IEEE CS-Press (1993) 216-225.

E. Clarke, E. Emerson, S. Jha, and A. Sistla, “Symmetry reductions in model checking,”

in Proceedings of Computer Aided Verification, A. Hu and M. Vardi, Eds., vol. 1427.

Springer, 1998, pp. 147–158.

E. Emerson and R. Trefler, “From asymmetry to full symmetry: New techniques for

symmetry reduction in model checking,” Correct Hardware Design and Verification

Methods, pp. 704–704, 1999.

A. P. Sistla, V. Gyuris, and E. A. Emerson, “SMC: A symmetry-based model checker

for verification of safety and liveness properties,” ACM Transactions on Software En-

gineering and Methodology, vol. 9, no. 2, pp. 133–166, 2000.

Dragan Bosnaki, D. Dams, and L. Holenderski, “Symmetric Spin,” International Journal on Software Tools for Technology Transfer, vol. 4, no. 1, pp. 92–106, 2002.

A. F. Donaldson, A. Miller and Muffy Calder, “Finding symmetry in models of concurrent systems by static channel diagram analysis,” Electronic Notes in Theoretical Computer Science, vol. 128, no. 6, pp. 161–177, 2005.

E. Emerson and T. Wahl, “On combining symmetry reduction and symbolic representation for efficient model checking,” in Correct Hardware Design and Verification Methods, ser. Lecture Notes in Computer Science, D. Geist and E. Tronci, Eds. Springer

Berlin / Heidelberg, 2003, vol. 2860, pp. 216–230.