He is responsible for the data set calibration, development of the data processing pipeline, error analysis and dataset validation, co-coordinator of the calibration paper.
Step 1: Set calibration grid, as shown in Figure 5. Step 2: Calculate the position of each calibration point in the subimage, (N r,N a).
Split data set calibration models, which accounted for country-level covariates and other sources of heterogeneity, effectively adjusted FAO estimates to approximate estimates from national survey data (r = 0.47 0.80) with small SEs of prediction (generally 1 5 g/d).
With an increasing size of the calibration set, the calibration reaches a steady state for a number of measurements of 10 and starts to deviate around a constant value which shows the performance limit of the ray tracing modeling method.
With the aid of this data set, calibration models were built based on 10 different chemometrics methods such as classical least squares (CLS), principal component regression (PCR), partial least squares (PLS), artificial neural networks (ANN) and others.
To evaluate the robustness of the dating in Gray et al[3], we re-estimated the age of the Austronesian expansion under a heavily reduced set of calibrations.
A blank and set of calibration standards were used to establish a three-point calibration curve.
These were set as calibration standard concentrations producing signal to noise ratio of 3 and 10 respectively.
Since ANNs are supervised classification systems, spectra are split into a training set for calibration, a pre-validation set and a test set for internal validation.
In the test set, the variables were pre-processed in the same way as for the calibration set, using the global calibration set means and standard deviations.
