ELSEYTER

THEMATICS AND

COMPUTERS SIMULATION

Mathematics and Computers in Simulation 44 (1997) 23 1

Preface

This special issue contains selected simulation papers presented at the 18th international conference on Znfomzation Technology Interfaces, ZTZ’96, held in Pula, Croatia, during 18-21 June 1996. The annual IT1 conference traditionally contains a strong simulation section with a number of contributors, and each year hosts simulation-oriented invited papers. The list of invited simulation speakers includes such simulation authorities as Robert Sargent, Michael Pidd, Ray Paul, Felix Breitenecker, Andrew Seila, Andras Javor, Ivan Futo and Brian Dangerfield.

This selection of papers from the ITI’ conference includes six papers devoted to different research and application aspects of simulation modeling. The paper by R. Sargent presents a novel simulation modeling paradigm, hierarchical control flow graphs (HCFG) and their use in building of queueing systems. HCFG model development is supported by the use of hierarchy, encapsulation, reuse and graphical representation. The paper by V. CeriC presents visual interactive modeling and simulation of the railway transport flows for NATO strategic deployment in Bosnia done at the end of 1995 and beginning of 1996. The paper describes development of the visual interactive model and presents simulation abilities of the model. The following paper by M. Slamic et al. is focused on the fixed-view point representation of synthetic environment for the low-cost industrial and military simulators. The authors discusses the possibilities of environmental visualization process simplifications without reducing the image quality.

The paper by Tz. Georgiev et al. describes mathematical modeling of fed-batch fermentation processes for amino acid production. Nonlinear dynamic models based on the stoichiometric equations are used and the adequacy of the proposed model is proved by simulation. In another paper in the biotechnology area, 2. Kurtanjek presents a principal component analysis of bioreactor fed-batch operation by computer simulation. The nonlinear and nonstationary model of the production process includes the proportional and integral feedback control loop for concentration of the secondary product, and the simulation data are decomposed into principal components in view of their application in process modeling, monitoring and control by neural networks.

The final paper by G. Stojanov et al. gives an overview of approaches to the construction of artifical autonomous agents within the behaviour based AI. An interactionist-expectative theory of agency and learning is then presented and its instantiation through a simulated autonomous agent called Petitage is demonstrated. Two types of simulation experiments were performed: one by explicitly given interaction graph and another by physically realistic simulation of the simulated agent and its environment.

Zagreb, March 1997 Vlatko Ceric

University of Zagreb

0378-4754/97/$17.00 0 1997 Elsevier Science B.V. All rights reserved PIISO378-4754(97)00046-3