Estimation performance of the adopted oscillator ensemble models applied on 100 samples of type A films, picked randomly from the fully-synthetic data set.

EEd: R2-score between original and estimated thickness values, mEEn: median of R2-scores between original and estimated n(λ) arrays; mEEk: median of R2-scores between original and estimated k(λ) arrays; mEER: mean of R2-scores between original and estimated R(λ) arrays; mEET: mean of R2-scores between original and estimated T(λ) arrays; SR: success rate = number of successful occasions (nss)/ total occasions (ns); and mFE: average number of function evaluations: ; and mFE denotes the average number of function evaluations (iterations × population size).