Machado, J.A.TenreiroLopes, António M.2015-11-192015-11-192015http://hdl.handle.net/10400.22/6940This paper analyzes several natural and man-made complex phenomena in the perspective of dynamical systems. Such phenomena are often characterized by the absence of a characteristic length-scale, long range correlations and persistent memory, which are features also associated to fractional order systems. For each system, the output, interpreted as a manifestation of the system dynamics, is analyzed by means of the Fourier transform. The amplitude spectrum is approximated by a power law function and the parameters are interpreted as an underlying signature of the system dynamics. The complex systems under analysis are then compared in a global perspective in order to unveil and visualize hidden relationships among them.engComplex systemsDynamical systemsFourier transformVisualizationjournal article10.1007/s11071-014-1645-1