The finding that σμ, which measures the variation in efficiency, is much (at least a factor 35) larger than σν, which measures random variation, adds to this conclusion.
The mean variation between measurements within sessions was 10%, which includes random variation and variation due to environmental effects.
Since the concentration is affected by how long the production rate term deviates from its average value, the time step over which the random variation is changing also affects the concentration variability.
Previous disease mapping work was based on collating, mapping and analysing prevalence or incidence data with conventional statistical approaches, which are affected by random variation due to population variability and a loss of statistical power when cases are assigned to subgroups (e.g., several geographic subareas).
Children were assigned a baseline FEV1% which was affected by daily random variation as well as external conditions including pollutant exposures.
However, non-negligible standard errors for non-standardised expected survival were observed, which can be explained by the random variation of the age distribution of the sample.
Furthermore, the reported incidences in our review varied widely between studies, which may be explained by random variation due to the small sample sizes of most included studies, but also by differences in patient populations and by misclassification (that is, not all episodes of AF may have been correctly detected).
The fluctuation of network connectivity ratio in Fig. 6 is also caused by the random variation of the distribution relationship, which is familiar with the fluctuation in Fig. 4.
But the differences that the researchers observed were much greater than what could be explained by random variation alone, suggesting that "survival of the fittest" played an important role.
