in this paper, we have studied the effect of population on iranian economic growth by using optimal growth theory. optimal growth theory is a nonlinear dynamic planning. classical approaches in mathematics are used for solving these nonlinear systems. but, in this study, we have used genetic algorithm (ga) method. as results show, it seems that population growth in previous years (1350- 1386), ...

The population growth, is increase in the number of individuals in population and it depends on some random environment effects. There are several different mathematical models for population growth. These models are suitable tool to predict future population growth. One of these models is logistic model. In this paper, by using Feynman-Kac formula, the Adomian decomposition method is applied to ...

in this study, age and growth for two populations of shemaya, chalcalburnus chalcoides, in haraz and shirud rivers were investigated from april to june 2006. 704 fish specimens were collected using a cast- net. the maximum length and weight in a 5- year old female observed were 251 mm and 96 gr, respectively. the most abundant age groups were 2+ and 3+ years for male and female respectively. wh...

There is growing awareness of the need for fishery management policies that are robust to changing environmental, social, and economic pressures. Here we use conventional bioeconomic theory to demonstrate that inherent biological constraints combined with nonlinear supply-demand relationships can generate threshold effects due to harvesting. As a result, increases in overall demand due to human...

population in all countries plays a fundamental role in economic growth and economic development. but besides absolute size and growth rate of population, the more important factor will be “age structure” or “age distribution” of population, because it can be as source of many economical, social, and political challenges. in this research, we investigate effect of changes in population shares i...