The chemical composition of the sample was then determined, and equations corresponding to linear combinations of the source profiles were solved using an effective variance-weighted least-squares analysis technique (Watson et al. 1984, 2001).
This may be due to a lack of effective variance in the number of training sessions among the WMT groups (see " Training data") since the amount of training was controlled and we did not include this analysis as a primary method to reveal the effects of WMT.
The current protein concentration is effectively an average over these samples, so the effective variance is reduced to <img src="http://journals.plos.org/plosone/article/asset?id=info?doi/10.1371/journal.pone.0002774.e085.PNG" class= inline-graphic"/> Except for the factor of g0 that converts n into g, this is the first term in Eq (57).
In summary, our dust model can be described with only seven parameters: real (m 0) and imaginary (k 0) parts of RI of silicate substrate, volume mixing ratio of hematite inclusion (ρ A ), effective radius (r eff) and effective variance (v eff) of size distribution, and optical depth and scale height (z s ) of extinction coefficient at wavelength 550 nm.
Sampling variance alone results in bias toward zero, but this bias is even larger when heterogeneity is present since this results in a further increase in dispersion (or the effective variance) of the results.
To address this, effective variance reduction techniques have been developed and implemented into MC codes.
The effective variance, however, shows decreased performance with the correlation coefficient of 0.46421.
The effective variance is slightly worse with the correlation coefficient of 0.76938.
Effective variance reduction techniques are required to further reduce the simulation times in MC-based SPECT reconstructions.
Authors of [14] suggest that the visually effective variance should be used to compute the distortion thresholds.
This may be due to the strong nonlinearity dependence of the scattering properties on the effective variance.
