Model fitting summary.

Note. Description lists model components (SCUWA) used to calculate the alertness score. Subscripts indicate the presence of the “brake function” described in equation 2–3 for process S (B), if the phase of C was different from the default p = 16.8 h based on circadian type (T) or set at 15 h (p15h) for all subjects, and the daily acclimatization rate for process A (%). log L = log likelihood. ε = residual standard deviation. η = subject level random effect standard deviation. All models (except 1a & 1b) are based on equation 11 and differ only in how the alertness score was calculated. Deviance indicate 2*- log likelihood difference (chi2) compared to selected models (vs). Transfer to KSS describes the best fitting constant (a) and coefficient (b) to transfer the alertness score to KSS (equation 9).Model fitting summary.