Table 1 Parameters of the double-exponential function used to model the relationship between single-count rates S and activity concentration A = fS → A(S), and the inverse relationship between activity concentration A and single-count rates S = fA → S(A), both for the ingenuity (fIng) and Vereos (fVer) cameras. Two goodness-of-fit criteria are additionally provided for each regression: the coefficients of determination (R2) and the root mean square error (RMSE)
|  |  | Exponential regression parameters y = aebx + cedx | Goodness of fit | ||||
|---|---|---|---|---|---|---|---|
| Â | Â | a | b | c | d | R2 | RMSE |
S = fA → S(A) | \( {f}_{A\to S}^{Ing} \) | 76.42 | 0.006298 | − 73.95 | − 0.020330 | 1.0000 | 0.22910 |
\( {f}_{A\to S}^{Ver} \) | 183.6 | 0.001547 | − 183.2 | − 0.006269 | 1.0000 | 0.07143 | |
A = fS → A(S) | \( {f}_{S\to A}^{Ing} \) | 368.9 | 0.004056 | − 370.2 | 0.002680 | 0.9999 | 0.22390 |
\( {f}_{S\to A}^{Ver} \) | − 117.9 | − 0.001315 | 117.6 | 0.004609 | 1.0000 | 0.06627 | |