Identification of Fractional-Order Transfer Functions Using a Step Excitation. - Luiz Antonio Jacyntho; Marcelo Carvalho Minhoto Teixeira; Edvaldo Assunção; Rodrigo Cardim; Roberto Kawakami Harrop Galvão; Sillas Hadjiloucas (IEEE Trans. Circuits Syst. II Express Briefs, 2015)