# Control vector analysis for noise reduction with constraint tolerance.

figure

posted on 12.01.2012, 01:10 by Kyung H. Kim, Herbert M. Sauro(a) When the vector length of is small, the change in the mean level due to a parameter perturbation, although directed not perpendicular to , can be negligible within a certain tolerance level (tol). The parameter perturbation can be applied toward a direction that deviates from the perpendicular plane to by an angle less than (defined in Eq (16)). (b–d) The angle between and is modified differently depending on where is placed.