An age-structured bioeconomic model, which is completely continuous in age and time, is developed in order to compare with traditional discrete models. Both types have advantages and disadvantages. The continuous framework complements discrete models as it allows for deeper and more transparent analytical study and leads to analytical results that would be difficult to achieve within a discrete framework. To make the model realistic, a nonlinear recruitment function is introduced and steady state solutions and constant-effort optimal fishing are studied analytically. In addition, the framework has been used for numerical analysis. Simulations are used to investigate how optimal harvesting patterns vary with parameter values.
The relevance of research is due increased environmental tensions associated with the noise impact of transport, including the problem of aircraft noise. The purpose of the study is the development of reduce the с on the population living near airports, and assessment of the cost-effectiveness of measures to implement measures to reduce noise interference with the device of green roof systems on residential and public buildings near aviation facilities. The predominance of green spaces, architectural forms and other elements of improvement contribute to improving the environment, quality of life, including by reducing the noise load. Based economic analysis and assessment of the noise situation use greening strucrures that improve the well-being of the local population, this particularity concerns the provision of health and psychological comfort of the population. The assessment of the ecological and economic efficiency of green roof systems has shown that the benefits of the green spaces are multifunctional, and in addition to reducing noise, they also reduced the island's effect of heat by creating a shadow, reduce the need for conditioning, reduce wind load, filter harmful emissions, improve air quality and preserve biodiversity.