In this paper, we consider an optimal control model governed by a class of delay differential equation, which describe the spread avian influenza virus from poultry to human. We take three variables into model, namely: slaughtering susceptible and infected (\begin{document}$ u_{1}(t) $\end{document}), edu...

The development of the Cyprus Stock Exchange together with the increasing trend of investors’ presence in financing activities has led to the importance of this market. In such circumstances, the first step towards a sustainable development of the Exchange is to support the investors. Risk of bankruptcy for the investee is a major challenge that an inexperienced stock investor encounters. In th...

This paper uses a theory of composition based on existential and universal properties. Universal properties are useful to describe components interactions through shared variables. However, some universal properties do not appear directly in components specifications and they must be constructed to prove the composed system. Coming up with such universal properties often requires creativity. Th...