Sharif Digital Repository

In this study, we will examine persistence of various kinds of seasonally forced epidemiological models and seasonally varying predator-prey models. The results of our study regarding persistence of the models will be shown via basic reproduction number. We will show that, in the framework of our study and under some conditions, persistence is obtained as long as the basic reproduction number is bigger than one. We will also prove that, in the framework of our study and under sufficient conditions, if the basic reproduction number is smaller than one, the species under discussion won’t survive in the predator-prey models, and the disease(s) would go extinct in the epidemiological... 

Family businesses comprise the majority of businesses in the world and in Iran as well, However, many of them fail in their succession to the next generation. Hence, the factors influencing family business succession has been studies by many researchers in the past decades. To contribute to the present literature, our study addresses one of the factors which is assumed to be influential on children choice about whether to enter their family business. The literature proposes that the presence of the siblings in the family business has both positive and negative effects on one's decision about whether to enter the family business or not. The positive effect stems from one's desire to work...