Several corrections were not applied at the proofreading stage. The Production team regrets the errors, and presents the corrections here. These corrections do not aect the scientific outcomes of the paper.(1) On page 6, there should be a '.' at the end of the last one of the equation (6).(2) On page 6, there should be a '.' at the end of the equation (7).(3) On the 6th row of page 7, there is an extra x˙ in the expression of d 34 .(4) On the 7th row of page 7, ' and x 1 (0), x 2 (0) and x 3 (0) are the initial conditions'.should be corrected into 'and x 1 (0), x 2 (0), x 3 (0), x˙0 1 ( ), x˙0 2 ( ), x˙0 3 ( ) are the initial conditions'.