Table 1 Adaptive performance specifications: decision factors.

Improvement factor

\(F_{r} = \left| {U(L_{S}^{(i)} ({\boldsymbol{x}}^{tmp} ),{\boldsymbol{F}}) - U(L_{S}^{(i)} ({\boldsymbol{x}}^{(i)} ),{\boldsymbol{F}})} \right|\)

Determines potential for design improvement starting from x⁽ⁱ⁾

Distance between the actual and target operating frequencies

\(D_{c} = ||{\boldsymbol{F}}_{c} - {\boldsymbol{F}}||\)

where

F_c = [f_c.1 … f_c.N]^T (actual operating frequencies)

F = [f₁ … f_N]^T (target frequencies)

Used as a safeguard to ensure that the updated specifications are sufficiently close to the current operating frequencies