\(e(s_{j})=\sum_{i=1}^{I}{\lambda_{i}(s_{j})\bullet e(S_{i})}\) \(=\sum_{i=1}^{I}{\lambda_{i}(s_{j})\bullet\left[Z\left(S_{i}\right)-f_{\text{SVR}}\left(X_{k}\left(S_{i}\right)\right)\right]}\),
(6)