## 3 Calculation  
This section describes the procedure for solving both parts of the classification task. Partial results are presented at each step, and the next step is determined. **Step 1: Selection for signal attributes for classification and estimate record length to calculate attributes. **  
There were 16,384 values for each type of rock. In order to obtain information about the nature of the data, time series were created from the data from ranked values, and the following attributes were calculated for them (Table 2):  
* \(Sum\_of\_abs\) (mm\(\cdot\)s\({}^{-2}\)) \[Sum_{of\_abs}=\sum_{i=j}^{j+l-1}\lvert vibro\_signal\rvert\] (2) where \(j\) is the order of the start point of the time series sequence, \(l\) is the length of the time series sequence and the number of points of the time series;  
\(Sum\_0\) (mm\(\cdot\)s\({}^{-2}\))--the sum of real value (mm\(\cdot\)s\({}^{-2}\))  
\[Sum_{o}=\sum_{i=j}^{j+l-1}\mathit{vibro\_signal} \tag{3}\] \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline
**Object** & **Start Order** & \(Sum\_of\_abs\) & \(Sum\_o\) & _Fluctua-tion_ & \begin{tabular}{c} _Count_ \\ _peaks\_10_ \\ \end{tabular} & \
\begin{tabular}{c} _Count_ \\ _peaks\_15_ \\ \end{tabular} &
\begin{tabular}{c} _Count_ \\ _peaks\_20_ \\ \end{tabular} & _Variab_ & _Skew_ & _Kurt_ \\ \hline l\_1 & 1 & 4665.05 & 180.88 & 498 & 125,250 & 125,249 & 125,249 & 136.53 & \(-0.26\) & 3.11 \\ l\_2 & 501 & 4052.12 & \(-987.00\) & 56 & 166 & 77 & 29 & 101.65 & 0.56 & 3.17 \\ l\_3 & 1001 & 4467.58 & 358.89 & 63 & 175 & 97 & 41 & 133.05 & \(-0.10\) & 3.30 \\ \hline g\_1 & 1 & 4318.03 & 276.94 & 499 & 125,249 & 125,249 & 125,249 & 118.74 & 0.08 & 3.01 \\ g\_2 & 501 & 4809.68 & \(-963.82\) & 50 & 219 & 116 & 34 & 132.10 & 0.12 & 2.37 \\ g\_3 & 1001 & 4446.05 & 149.36 & 56 & 183 & 99 & 34 & 125.23 & 0.17 & 2.81 \\ \hline a\_1 & 1 & 5946.27 & \(-622.32\) & 499 & 125,250 & 125,250 & 125,250 & 216.53 & 0.03 & 2.64 \\ a\_2 & 501 & 7080.23 & 113.09 & 48 & 298 & 206 & 135 & 301.41 & 0.04 & 2.70 \\ a\_3 & 1001 & 5583.08 & \(-745.50\) & 48 & 218 & 122 & 67 & 216.70 & \(-0.42\) & 4.47 \\ \hline c\_1 & 1 & 3217.27 & \(-953.86\) & 498 & 125,249 & 125,249 & 125,249 & 63.18 & \(-0.24\) & 3.06 \\ c\_2 & 501 & 3302.33 & 68.39 & 44 & 109 & 36 & 20 & 74.16 & \(-0.07\) & 3.90 \\ c\_3 & 1001 & 2982.76 & \(-214.89\) & 42 & 92 & 13 & 0 & 53.30 & \(-0.03\) & 2.42 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: The properties of the tested rock. * _Fluctuation_--fluctuation through zero is the number of times the sign of the vibration signal changes in the time series;
* _Count_peaks_10_ is count of the number of points of the time series in which the absolute value of the vibration signal is higher than 10 mm\(\cdot\)s\({}^{-2}\);
* _Count_peaks_15_ is count of the number of points of the time series in which the absolute value of the vibration signal is higher than 15 mm\(\cdot\)s\({}^{-2}\);
* _Count_peaks_20_ is count of the number of points of the time series in which the absolute value of the vibration signal is higher than 20 mm\(\cdot\)s\({}^{-2}\);
* _Variab_ is var of time series (mm\(\cdot\)s\({}^{-2}\))\({}^{2}\);
* _Skew_ is the skewness of time series, a coefficient, so it has no units;
* _Kurt_ is a kurtosis time series, a coefficient with no units. **Step 2: Evaluation of the attributes' suitability**  
This section describes how the signal sequence's attributes and length were selected for classification. Sequences of 500 values were created from the vibration signal recording for each rock. Thus, 32 objects from each rock were created. Table 2 shows the attributes of the first three objects for each rock. The start order value is the sequence number of the first point of the vibration signal of the rock for which the attributes of the object's vibration signal have been calculated. Each row of Table 2 is a vector of an object. The object label consists of the first letter of the material name and the object's serial number.