A lot of researchers are developing new DEM parameters calibration approaches based on an experiment plan or the use of learning algorithms. This research is aimed at improving iterative algorithms frequently used for calibration. The big time consumption as a main problem of iterative algorithms is questioned. It is proposed to use Random forest algorithm to determine DEM parameters impact on the measured bulk responses. Measured responses are the parameters obtained by image processing using a technical vision system. As a result of 200 experiments processing, DEM parameters impact values on each bulk response were generated and presented as histograms. Obtained results were interpreted on the basis of the bulk material behavior and its physical properties. There is a discussion on the possibility of developing a universal DEM parameters calibration method based on the iterative algorithm.

In the article the process of destruction of the array of Cambrian clays by cutting, as a dynamic contact problem of mechanics, solved with using the software environment ANSYS Worbench, is observed. The obtained results are verified on a laboratory bench setup with experimental investigations. Analysis of the results of computational and laboratory experiments shows that in the framework of theoretical and experimental approach to solving problems of continuum mechanics, as an integral part of the basic research a finite element method can be used, which lets adequately and with sufficient accuracy to determine the power and energy indicators of process of destruction of the clay arrays by cutting. A characteristic feature of the process of destruction of flooded Cambrian clays is significant plastic deformation of rocks at the contact with the cutter. The separation of the elements of destruction from the array occurs under the action of shearing stress by the formation of shear cracks. High viscosity of arrays of Cambrian clays defines a large share of energy consumption on their destruction, comparable in value to the energy intensity of the process of cutting of hard coal and salt rocks. The use of computer simulation can significantly reduce the duration and increase the accuracy of design calculations at designing of the actuating devices of mining machines.

This article is devoted to expanding the possibilities of assessing the technical state of the current consumption of asynchronous electric drives, as well as increasing the information capacity of diagnostic methods, in conditions of limited access to equipment and incompleteness of information. The method of spectral analysis of the electric drive current can be supplemented by an analysis of the components of the current of the Park's vector. The research of the hodograph evolution in the moment of appearance and development of defects was carried out using the example of current asymmetry in the phases of an induction motor. The result of the study is the new diagnostic parameters of the asynchronous electric drive. During the research, it was proved that the proposed diagnostic parameters allow determining the type and level of the defect. At the same time, there is no need to stop the equipment and taky it out of service for repair. Modern digital control and monitoring systems can use the proposed parameters based on the stator current of an electrical machine to improve the accuracy and reliability of obtaining diagnostic patterns and predicting their changes in order to improve the equipment maintenance systems. This approach can also be used in systems and objects where there are significant parasitic vibrations and unsteady loads. The extraction of useful information can be carried out in electric drive systems in the structure of which there is a power electric converter.