# Experimental Research on Unit Operation for Fruit Crops' Bones Calibration
## 3 Results and Discussion
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Fruit Crops**} & \multicolumn{2}{c}{**Factors**} & **n, fluct/min** & **A, mm** & \multirow{2}{*}{**\(\boldsymbol{\beta}\), deg**} \\ \cline{2-4}  & **The Coded Designation** & **X1** & **X2** & **X3** \\ \hline \multirow{4}{*}{Cherry} & Variation Interval & 45 & 2.5 & 2.5 \\ \cline{2-4}  & Basic level (0) & 455 & 7.5 & 9.5 \\ \cline{2-4}  & Top level (+1) & 500 & 10.0 & 12.0 \\ \cline{2-4}  & Lower level (\(-1\)) & 410 & 5.0 & 7.0 \\ \hline \multirow{4}{*}{Sweet cherry} & Variation Interval & 65 & 2.5 & 3.0 \\ \cline{2-4}  & Basic level (0) & 415 & 7.5 & 7.0 \\ \cline{2-4}  & Top level (+1) & 480 & 10.0 & 10.0 \\ \cline{2-4}  & Lower level (\(-1\)) & 350 & 5.0 & 4.0 \\ \hline \multirow{4}{*}{Cherry plum} & Variation Interval & 70 & 2.5 & 3.0 \\ \cline{2-4}  & Basic level (0) & 430 & 7.5 & 7.0 \\ \cline{2-4}  & Top level (+1) & 500 & 10.0 & 10.0 \\ \cline{2-4}  & Lower level (\(-1\)) & 360 & 5.0 & 4.0 \\ \hline \multirow{4}{*}{Apricot} & Variation Interval & 50 & 1.5 & 4.0 \\ \cline{2-4}  & Basic level (0) & 450 & 8.5 & 6.0 \\ \cline{2-4}  & Top level (+1) & 500 & 10.0 & 9.0 \\ \cline{2-4}  & Lower level (\(-1\)) & 400 & 7.0 & 3.0 \\ \hline \multirow{4}{*}{Almond} & Variation Interval & 50 & 2.0 & 2.0 \\ \cline{2-4}  & Basic level (0) & 430 & 8.0 & 5.0 \\ \cline{1-1} \cline{2-4}  & Top level (+1) & 480 & 10.0 & 7.0 \\ \cline{1-1} \cline{2-4}  & Lower level (\(-1\)) & 380 & 6.0 & 3.0 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Factors variation intervals. * variance of reproducibility by the results of the experiments in the center of the de-sign was calculated \(D_{m}\) (Table 3);
* variances characterizing the errors in determining the coefficients of the regression equation were found;
* the confidence interval of the regression coefficients was calculated using Student's \(t\)-criterion, with the number of degrees of freedom \(f=N\cdot(\gamma-1)=28\). Its value is found from the tables [31]; in our case it is \(t_{\sigma}\) = 2.05;
* confidence intervals are compared to the values of regression coefficients. Checking the significance of the regression coefficients of the obtained model allows rejection, with 95% confidence, of the least significant coefficients: cherries \(b_{33}\), sweet cherries \(b_{22}\), cherry plum \(b_{23}\), apricot \(b_{12}\) and \(b_{13}\), almond \(b_{12}\). To check the homogeneity of the dispersions of the reproducibility of the experiments, [PERSON]'s criterion was used. With the help of this criterion, the repeatability of experiments is checked within certain measurement limits with a given confidence level. The number of experiments was \(k\) = 14, the number of degrees of freedom \(f\) = 2, the number of repetitions of the experiments was 3. The tabular value of [PERSON]'s criterion, in accordance with [31]\(G_{tab}\) = 0.35. Calculated values of [PERSON]'s criterion Gp are obtained:  
* for cherries \(G_{p}\) = 0.21;
* for sweet cherries \(G_{p}\) = 0.31;
* for plum cherries \(G_{p}\) = 0.2;
* for apricots \(G_{p}\) = 0.29;
* for almonds \(G_{p}\) = 0.27. It was found that for all crops \(G_{p}<G_{tab}\); hence, the reproducibility dispersion is homogeneous. By the tightness of the relationship between the experimental and theoretical regression, one can judge the presence of a correlation. To determine the percentage of scatter of the desired response function (\(y\)) relative to its average value, determined by the variability of the factors \(x_{1}\), \(x_{2}\), \(x_{3}\), regression statistics of mathematical models (4)-(8) were calculated:  
* coefficient of multiple correlation \(R\);
* coefficient of determination \(R_{2}\) (\(r\)-square). The calculation results are presented in Table 3.  
The coefficient of determination for all cultures averages \(R_{2}\) = 0.87. This means that on average 87% of the spread is due to variability and 13% to other causes. This means that the variability of the function (\(y\)) is almost completely characterized by a spread of factors.