For each of the 48,268 premise IDs, CVRMSE (equation 5) and NMBE
(equation 6) were calculated between it and its matched prototype building.
= [[summation].sup.N.sub.i=1]([E.sub.i] - [P.sub.i])/[[summation].sup.N.sub.i=1][E.sub.i], (14)
= 100 x[([summation](yi-[??]i))/(n-1)]/[bar.y] (2)
Equal weighting factors for kWh/kW/gas utility bills are assumed, while a ratio of 3:1 has been selected for NMBE
The calibration results were found to be well within the acceptable limits of the NMBE
and CvRMSE criteria and thus are satisfactory.
Calculating the indices, the modified model has a CVRMSE of 12.24% and an NMBE
of 11%, while the default model has a CVRMSE of 14.4% and 8.16%.
Statistical indicators for Monthly Calibration of the Sample Buildings Sample Building NMBE
, % CVRMSE, % 1 -2.6 8.7 2 5.0 3.4 3 1.2 6.3 Table 3.
The coefficient of variation of the root-mean-square error (CV[RMSE]) and normalized mean bias error (NMBE
) were also calculated for each fitted model, shown in the following equations:
Eight specimens (Natural History Museum of Los Angeles County, LACM 146192-146197, Los Angeles, California, USA; Smithsonian Tropical Research Institute, STRI 0113, Panama; Naturhistoriches Museum Bern, NMBE
1049173-1049174, Switzerland) of A.
ASHRAE Guideline 14 suggests two main indicators: normalized mean bias error (NMBE
) and coefficient of variation of the root mean square error (CVRMSE).
For the section least fitting with the experimental data, a temperature fit having a normalized mean bias error (NMBE
) of 4.74 and coefficient of variance of the root mean square error (CV[RMSE]) of 5.79 is calculated for the charging case and a NMBE
of 4.18 and CV(RMSE) of 4.27 for the discharging case.
The statistical indices of the coefficient of variation of the root-mean-square error (CV-RSME) and normalized mean bias error (NMBE
) were used for the model validation process.