Machado, J. A. TenreiroGalhano, AlexandraOliveira, AnabelaTar, József K.2014-04-042014-04-0420091007-5704http://hdl.handle.net/10400.22/4309This paper addresses the calculation of fractional order expressions through rational fractions. The article starts by analyzing the techniques adopted in the continuous to discrete time conversion. The problem is re-evaluated in an optimization perspective by tacking advantage of the degree of freedom provided by the generalized mean formula. The results demonstrate the superior performance of the new algorithm.engFractional derivativesFractional calculusAverageGeneralized meanjournal article10.1016/j.cnsns.2009.03.004