Smoothing, data handling

Different spectral preprocessing and transformations available in SIMCA P-p (version 10.0, Umetrics, Sweden) were evaluated and the best approach for data handling and manipulation was determined. Data collected on the surrogate tablets were divided into a training set to generate the PLS models, and prediction set to test the PLS models. MCC powder, equilibrated at different RH, was also roller compacted at different roll speeds on a Fitzpatrick IR220 roller compactor fitted with smooth rolls. Powder feed rate and roll pressure were kept constant for all experiments. The key sample attributes measured on the surrogate tablets were also measured for the samples prepared by roller compaction. 

Recently, Neupauer et al. [53] performed a study to compare the TR and the MRE methods. They found that both methods perform well in reconstructing a smooth source function. For an error free step function source history, the MRE performs better than the TR. On the other hand, the TR method is more robust in handling data that contain measurement errors. Neupauer and coworkers used measurement errors of 1%, 5%, and 25%. 

X.Q. Lu and J.Y. Mo, Methods of Handling Discrete Data for Deconvolution Voltammetry (I) Wavelet Transform Smoothing, Chemical Journal of Chinese University, 18 (1997), 49-51 (in Chinese). 

Due to the inversion step, DFA cannot handle collinearity and therefore can only analyse data matrices containing independent variables. A common way to accomplish this is to perform a PCA on the original data and only use the orthogonal scores vectors in the DFA routine. In the experiments performed the number of principal components used corresponds to 99.99% of the total variance. Using the same number of PCs for the different wavelet scales is not possible because data set reconstructed with very few scales are very smooth and have much fewer significant PCs. 

Figure 1.1 was first pubhshed by the United States Mineral Management Service (MMS)— the government agency responsible, at the time, for offshore safety regulation and enforcement. These responsibilities for the MMS are now handled by the Bureau of Safety and Environmental Enforcement— BSEE. The chart provides data to do with the number of offshore safety incidents for the period 1996 to 2011. The trend is impressive in just 12 years the recordable injury rate declined from 3.39 to 0.75, a drop of around 80 percent. And the number of lost workdays dropped by a similar percentage. Moreover the trend is quite smooth and steady, showing that the results are not a fluke or one-time event. And these... 

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