Authors
Perevaryukha A.
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Degree
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PhD in Technique, St. Petersburg Institute for Informatics and Automation of Russian Academy of Sciences |
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E-mail
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madelf@pisem.net |
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Articles
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Cognitive simulation in the analysis of structural interactions of environmental processes in Caspian seaEcological processes in the face of rapid changes in the environment as an object for the computer
simulation requires a flexible approach to the analysis. Article devoted to applications of the
conceptual structuring of ideas about the interaction natural and anthropogenous factors on the basis
of cognitive models. The formal analysis of pulses in the sign graph in the context of the situation
degradation bioresources of Caspian Sea has promoted the development of original hybrid dynamic
systems for modeling sturgeon fish reproduction. It is shown that the choice of the mathematical
approach to the description of the situation can be based on the results of cognitive analysis of the
ecological relationships. At the conclusion of results of computational studies should logically follow
the newly theoretical interpretation of the observed changes in behavior of models. Chosen structure
of the new models allows us to consider various scenarios of environmental emergencies. In cognitive
oriented graph possible to make hypotheses, but to assess the abrupt changes necessary to
investigate the nonlinear dynamics of the trajectory of some key characteristics, which for the Caspian
Sea is the effectiveness of fish spawning. In such models often arise bifurcations of attractors
with the appearance of cycles that effect on environmental implications.
Read more...
Dynamically overridden systems for modeling of the two population processes with threshold effectsWe have proposed a method for constructing dynamically redefined structures for the purpose of modeling abrupt changes in biological processes. The method provides for the analysis of scenarios with a control action, which is aimed at optimizing the profit from the exploitation of biological resources. The situations are described by three differential equations, which are numerically solved on adjacent time intervals. The state of the predicate set controls the selection of dynamically overridden coefficients. We carry out comparisons of all predicates on the basis of averaged individual indicators of generations. Threshold states in the dynamics of population size are a consequence of the selection of events as special nonequilibrium states that change the regulation algorithm. Our method makes it possible to implement dangerous qualitative changes in the scenarios of biological resource management, when the stable modes of their existence are suddenly lost. For practical problems, we have algorithmically implemented computational scenarios for two different processes such as the collapse of fish stocks under expert control of the fishery and a rapid outbreak of pests. The situation of the collapse of the fish population in the scenario with control develops in two stages and is a consequence of the experts 'desire to optimize the operation with uncertainty in an expert’s assessment of a state of a fishery. To confirm the relevance of our models, comparisons are made with the graphs of the development of the two real processes, as the spontaneous population explosion and the stock crisis during optimization of the sea cod fishery. Read more... |
