scholarly journals Influence of environmental nutrient conditions on Gymnodinium breve (Dinophyceae) population dynamics: a numerical study

2001 ◽  
Vol 213 ◽  
pp. 13-37 ◽  
Author(s):  
G Liu ◽  
GS Janowitz ◽  
D Kamykowski
Keyword(s):  
Population Dynamics ◽  
Numerical Study ◽  
Gymnodinium Breve ◽  
Nutrient Conditions

Dynamic modes of exploited limited population: results of modeling and numerical study

2016 ◽  
Vol 11 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Г.П. Неверова ◽  
G.P. Neverova
Keyword(s):  
Population Dynamics ◽  
Density Dependence ◽  
Population Size ◽  
Age Structure ◽  
Birth Rate ◽  
Numerical Study ◽  
Dynamic Regime ◽  
Demographic Parameters ◽  
Current Population

The paper investigates the model of population dynamics with age structure and density dependence of birth rate. We consider two situations: 1) the population develops freely and 2) the population is exploited. It was shown that harvesting leads to the stabilization of the dynamics. There is multiregimism, i.e. different dynamic regimes are possible with the same values of demographic parameters. It is shown that even a single harvesting in the current population size could lead to a change of the observed dynamic regime.

scholarly journals Synthesis and Computer Study of Population Dynamics Controlled Models Using Methods of Numerical Optimization, Stochastization and Machine Learning

Mathematics ◽  
2021 ◽  
Vol 9 (24) ◽  
pp. 3303
Author(s):  
Anastasia V. Demidova ◽  
Olga V. Druzhinina ◽  
Olga N. Masina ◽  
Alexey A. Petrov
Keyword(s):  
Machine Learning ◽  
Population Dynamics ◽  
Numerical Optimization ◽  
Numerical Study ◽  
Three Dimensional ◽  
Equilibrium States ◽  
Optimal Trajectories ◽  
Trophic Chains ◽  
Dimensional Models ◽  
Three Dimensional Models

The problems of synthesis and analysis of multidimensional controlled models of population dynamics are of both theoretical and applied interest. The need to solve numerical optimization problems for such a class of models is associated with the expansion of ecosystem control requirements. The need to solve the problem of stochastization is associated with the emergence of new problems in the study of ecological systems properties under the influence of random factors. The aim of the work is to develop a new approach to studying the properties of population dynamics systems using methods of numerical optimization, stochastization and machine learning. The synthesis problems of nonlinear three-dimensional models of interconnected species number dynamics, taking into account trophic chains and competition in prey populations, are studied. Theorems on the asymptotic stability of equilibrium states are proved. A qualitative and numerical study of the models is carried out. Using computational experiments, the results of an analytical stability and permanent coexistence study are verified. The search for equilibrium states belonging to the stability and permanent coexistence region is made using the developed intelligent algorithm and evolutionary calculations. The transition is made from the model specified by the vector ordinary differential equation to the corresponding stochastic model. A comparative analysis of deterministic and stochastic models with competition and trophic chains is carried out. New effects are revealed that are characteristic of three-dimensional models, taking into account the competition in populations of prey. The formulation of the optimal control problem for a model with competition and trophic chains is proposed. To find optimal trajectories, new generalized algorithms for numerical optimization are developed. A methods for the synthesis of controllers based on the use of artificial neural networks and machine learning are developed. The results on the search for optimal trajectories and generation of control functions are presented.The obtained results can be used in modeling problems of ecological, demographic, socio-economic and chemical kinetics systems.

Numerical study of microbial population dynamics in anaerobic digestion through the Anaerobic Digestion Model No. 1 (ADM1)

2013 ◽  
Vol 228 ◽  
pp. 87-92 ◽  
Author(s):  
Pasiano Rivas-García ◽  
José E. Botello-Álvarez ◽  
Alejandro Estrada-Baltazar ◽  
José L. Navarrete-Bolaños
Keyword(s):  
Population Dynamics ◽  
Anaerobic Digestion ◽  
Microbial Population ◽  
Numerical Study ◽  
Microbial Population Dynamics
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