Anisimova L. Simulating ecological-economical systems by means of Petri nets.

Methodology to study ecological-economical systems, that are described by balance equations of the Leontyev-Ford's type, is enriched by algorithmic dynamical simulation means. It is justified that for this purposes the most convenient tool is the technique of Petri nets. A special subclass of Petri nets in which Leontyev-Ford model is embedded is distinguished. Leontyev-Ford balance equations are derived from Petri nets as consequences. A polynomial algorithm depending on a system life-cycle time for finding productive cycles in Petri nets is suggested. This algorithm exploits the property of conditional commutability of elementary interactions. It can also be used for accelerating search procedures on decision trees for many artificial intelligence problems. Programming interpreter for generalized Petri nets is developed.