In this paper we develop an economic growth model that includes anthropogenic climate change. We explicitly include a research sector that creates new technologies and simultaneously expands productivities of existing technologies. The environment is affected by R&D activities both negatively, through increase of output from productivity growth, as well as positively, as new technologies are le...

â  â â â â â  â  â  abstract: â  there is a significant relationship between economic growth and the degree of urban concentration, as measured by primacy or the share of the largest city in an urban system. in accordance to urban economic theories, there is an inverse-u shape relationship between urban concentration –urban primacy- and economic growth. that is, as economy grows, urban concen...

A nonlinear control model of a firm describing the change of production and accumulated R&D investment is investigated. An optimal control problem with R&D investment rate as a control parameter is solved. Optimal dynamics of economic growth of a firm versus the current cost of innovation is studied. It is analytically determined that dependent on the model parameters, the optimal control must ...

Such a trade-off curve for time t might be as depicted in Figure 1. For the BSSDG model, a point on this time-t consumption-investment production possibility frontier is determined by the direct specification of a consumption demand function for c(t). For example, we considered the particular case in which consumption demand was More precisely, f(0) = 0, f(k) is continuous over all k ≥ 0 and tw...

The species Gracilariopsis persica was first described by Bellorin et al. (2008). G. persica grows from late September to July and shows high growth rate from January to May in the Persian Gulf. Tissue growth and branch induction of red seaweed, Gracilariopsis persica from the Persian Gulf investigated under various culture levels of temperature, light intensity, photoperiod, salinity, initial ...

  There is a significant relationship between economic growth and the degree of urban concentration, as measured by primacy or the share of the largest city in an urban system. In accordance to urban economic theories, there is an inverse-U shape relationship between urban concentration –urban primacy- and economic growth. That is, as economy grows, urban concentration increases, approaches a...

In this paper we first describe the stochastic optimal control algorithm called ((OPTCON)). The algorithm minimizes an intertemporal objective loss function subject to a nonlinear dynamic system in order to achieve optimal value of control (or instrument) variables. Second as an application, we implemented the algorithm by the statistical programming system ((GAUSS)) to determine the optimal fi...

The species Gracilariopsis persica was first described by Bellorin et al. (2008). G. persica grows from late September to July and shows high growth rate from January to May in the Persian Gulf. Tissue growth and branch induction of red seaweed, Gracilariopsis persica from the Persian Gulf investigated under various culture levels of temperature, light intensity, photoperiod, salinity, initial ...

the purpose of this paper is a study on the effect of cash flows on the gap between actual and optimal financial leverage ratio companies listed in tehran stock exchange. in this regard, we try to help with advanced econometric techniques such as partial adjustment model on panel data and generalized method of moments to achieve a reasonable estimate of the impacts.in this paper, were analyzed ...