One may find out the application‎ ‎of mathematics in the areas of ecology‎, ‎biology‎, ‎environmental‎ ‎sciences etc‎. ‎Mathematics is particulary used in the problem of‎ ‎predator-prey known as lotka-Volterra predator-prey equations.‎ ‎Indeed‎, ‎differential equations is employed very much in many areas‎ ‎of other sciences‎. ‎However‎, ‎most of natural problems involve some‎ ‎unknown functions...

abstract exchange rate volatility is one of the effective and ambiguous factors in agricultural products export. regarding the importance of agricultural trade, to avoid single-product economy, the main aim of this study is to investigate the impact of exchange rate volatility on the pistachio export of iran during 1338-1386. for this purpose, exchange rate volatility index was estimated using ...

in this study, the longitudinal shrinkage behavior of knitted fabrics during drying has been studied. in this context, a model is presented to predict the longitudinal shrinkage of plain knitted fabric during drying process. in order to model the shrinkage behavior, a 1dof model consists of a mass, a linear spring and a linear damper have been used. in presented model the time-varying mass is c...