“…Introduction. Modelling and optimal control of many practical systems in engineering, science and economics traditionally involve Ordinary Differential Equation (ODE) systems of integer orders [2,24,25,27,28,29,30]. While integer order ODE systems are adequate for capturing the evolution of most standard phenomena, it has been shown over the last two decades that many complex systems in solid mechanics, viscoelastics, gas diffusion and heat conduction in porous media, signal and image processing, bio-engineering, biology, economics and financial engineering are better modelled by systems with fractional or non-integer-order differential equations (cf., for example, [3,4,5,6,7,8,22,23,26]).…”