Fuzzy and related research at Veszprém University of Chemical Engineering (Department of Cybernetics)

Fuzzy and related research at Veszprém University of Chemical Engineering (Department of Cybernetics)

394 Bulletin 3. Fuzzy and Related Research at Veszpr(~m University of Chemical Engineering (Department of Cybernetics) The Department of Cybernetics...

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394

Bulletin

3. Fuzzy and Related Research at Veszpr(~m University of Chemical Engineering (Department of Cybernetics) The Department of Cybernetics was founded in 1977, headed by Prof. P(~ter Arva, with the aim of teaching mathematical modelling and computerized control for engineering students. Teaching activity is accompanied with basic and applied research in different topics of engineering cybernetics. The significance of the fuzzy paradigm in the representation of engineering problems was observed by Prof. ~,rva in 1983. Shortly a fuzzy control algorithm was developed and successfully tested for the regulation of an ill-designed heat exchanger [1,2]. Considerable results with hierarchic 'particularisation' of membership functions were obtained. In the next period the research group joined forces with Prof. B(~la Csukds, and the combination of crisp algebraic methods with fuzzy valuation as well as the evolutionary approach of process synthesis got into the limelight. Different types of fuzzy information [3, 4] in the synthesis problems were studied and fuzzy valued relational algebras for the formalisation of uncertainty change were proposed [5, 6, 7, 8]. The elaborated synthesising algorithms were applied to the solution of various problems [9, 10]. Recently the development of valuated structures has been motivated by the new possibilities of logic programming. A family of the evolutionary (learning) algorithms combining the tools of the Prolog structure representation with the model-based evaluation of generating facts followed by the rearrangement of the database was developed and applied [11, 12, 13]. The methods can easily be extended to multicriteria situations and even a new approach of multiobjective valuation of various hierarchic and cooperative systems is outlined. On the other hand new results in the field of fuzzy control are gained [14]. Our attention is focused especially on learning controllers and potential applications in the computerised control of a fermentation process. At the same time, the fuzzy modelling of a bioreactor is being studied. The general concept of these investigations is the optimum utilisation of human knowledge and imprecise information in the solution of engineering problems.

References [1] P. l~rva, J. Vass and J. D6n, Studies on fuzzy control algorithms, M~szaki Kdmiai Rendszerek "84, Csopak (1984) (in Hungarian). [2] P. ,~,rva and J. Vass, Studies on fuzzy control algorithms, M#r~s ~s Automatika 36 (1988) 39-42 (in Hungarian). [3] P. /~rva and B. Csukds, Fuzzy algebraic structures in chemical engineering design, Proceedings of MATCHEM '86, Balatonf(Jred(1986) Vol. 11/2,pp. 24-36. [4] P. /~rva and B. Csukds, Role of fuzzy information in design and control of chemical engineering processes, 9th International Congress CHISA "87, Prbga (1987). [5] B. Csuk~s and P. Arva, Recursive expert algorithm based on fuzzy valuation of relational algebraic structures, Progress of Fuzzy Sets in Europe, 2nd Workshop of lFSA EC and EURO WG, Warsaw (1986). [6] P./~rva and B. Csukds, Fuzzy valuated relational algebrae in chemical engineering, Hung. J. Ind. Chem. 15 (1987) 1-8. [7] B. Csuk;~s and P. /krva, Uncertain valuation over decomposition and composition of combinations, Paper submitted to IFSA 2nd World Congress, Tokyo (cancelled because of involuntary absence). 18] P. Arva and B. Csukds, Computer-aided process synthesis by fuzzy valuated structures, CompuL Chem. Engng. 12 (2/3) (1988) 215-224. [9] B. Csukds and P./~rva, Computer-aided synthesis of hydrocyclone network, 9th International Congress CHISA '87, Pr&ga (1987). [10] P. /~rva and 8. Csuk~s, Synthesis of engineering objects by recursive fuzzy valuation of crisp cornbinations, Fuzzy Sets and Systems 32 (1) (1989) 13-34. [11] B. Csukds, Z. Kozdr and P./krva, Multicriteria Valuated Prolog Synthesizing Algorithms, Comput. Chem. Engng. 13 (4/5) (1989) 595-602. [12] B. Csukds, Z. Zozdr and R. Lakner, Prolog structures and valuated prolog structures in process synthesis, Proceedings of the 5th Conference on Applied Chemistry, Unit Operations and Processes, Balatonf~red (1989) VoL 2, pp. 507-515.

Bulletin

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[131 B. Csuk~s, P. Arva and Z. Koz~r, Production control by logically described flexible, time-varied networks, Proceedings of the 5th Conference on Applied Chemistry, Unit Operations and Processes, Balatonf(Jred (1989) Vol. 1, pp. 444-450. [14] P. Arva and S. N6meth, Batch reactor fuzzy controlling. M~szaki K~miai Rendszerek '88, BalatonflJred (1988) (in Hungarian). Peter ~,rva H-8201 Veszprem Pf. 158 Hungary

4. Summary of Activities of the Group on Approximate Reasoning and Aritificial Intelligence of the University of Grenada At the beginning of 1988 the Department of Computer Science and Artificial Intelligence was founded in the University of Grenada, and the former GRA (Bulletin of the Journal Fuzzy Sets and Systems, 24, 1987) became the working Group on Approximate Reasoning and Artificial Intelligence (GARAI) by incorporating new members and starting new research lines. Currently, the GARAI is headed by Professor M. Delgado and it is constituted by twenty members (full professors, associated professors and assistants). In reference to Fuzzy Logic, actually two main research lines are being developed. (a) Approximate Reasoning and Decision-Making Models, headed by J. L. Verdegay, and (b) Knowledge Representation, headed by S. Moral. The GARAI develops the t w o following supported research projects, -Defeasible Reasoning and Uncertainty Management Systems (DRUMS): Propagating Uncertainty in Dependence Graphs (CEE-ESPRIT Basic Research Action No 3085), and -Applications of Fuzzy Logic in Optimization Problems (CICYT No PS88 0090). The Group has stable scientific relations with research groups at the Systems Research Institute (Polish Academy of Sciences), Warsaw (Poland), the Department of Statistics, University of Strathclyde, Glasgow (Scotland), and the Institute of Industrial Engineering and Management, Technical University of Wroclaw (Poland). The GARAI supports an active Seminar on Approximate Reasoning in which, in the last two years, among others, have participated as invited: J. Kacprzyk (Systems Research Institute, Warsaw, Poland), E. Ruspini (SRI International, California, USA), E. Sanchez (University of Marseille, France), M. Sugeno (Tokyo Institute of Technology, Japan), and T. Yamakawa (University of Kumamoto, Japan). The Group is interested in collaborations, in the framework of their main scientific interest areas which, at the present, are: The use of linguistic labels in Approximate Reasoning, propagation of uncertainty in graphs, evidential models for knowledge representation and optimization models in fuzzy environment. Some recent selected publications by members of the group are as follows.

References M. Delgado, J. L. Verdegay and M.A. Vila, Fuzzytransportation problems: A general analysis, in: J. Kacprzyk and S.A. Orlovski, Eds., Optimization Models Using Fuzzy Sets and Possibility Theory (Reidel, 1987), 342-358. M. Delgado, J.L. Verdegay and M.A. Vila, Imprecise costs in mathematical programming problems, Control and Cybernet. 18 (1987) 113-121. M. Delgado and S. Moral, On the concept of possibility-probability consistency, Fuzzy Sets and Systems 21 (1987) 311-318. M. Delgado, J.L., Verdegay and M.A. Vila, The Minimal spanning tree problem for fuzzy graphs, Trabajos de Investigacion Operativa 2 (1987) 3-20 (in Spanish). M. Delgado and S. Moral, A definition of inclusion for evidences, Fuzzy Mathematics 7 (1987) 81-87. M. Delgado, J.L. Verdegay and M.A. Vila, on fuzzy linear programming models, Preprints of Second IFSA Congress, Tokyo (July 1987) 715-718.