Machado, J. A. TenreiroPires, E. J. SolteiroCouceiro, Micael S.2015-01-272015-01-2720140924-090X1573-269Xhttp://hdl.handle.net/10400.22/5486We agree with Ling-Yun et al. [5] and Zhang and Duan comments [2] about the typing error in equation (9) of the manuscript [8]. The correct formula was initially proposed in [6, 7]. The formula adopted in our algorithms discussed in our papers [1, 3, 4, 8] is, in fact, the following: ...engVibrationDynamical SystemsControlMechanicsMechanical EngineeringAutomotive Engineeringjournal article10.1007/s11071-014-1302-8