A.V. Brovko – Ph. D. (Phys.-Math.), Associate Professor, Department «Applied Information Technologies», Yuri Gagarin State Technical University of Saratov
R.S. Pakharev – Post-graduate Student, Department «Applied Information Technologies», Yuri Gagarin State Technical University of Saratov
The paper presents the method of determining a volume fraction of firm particles in the powder material located in the closed waveguide measuring system. The considered method is of great practical interest as the received decision can be applied in many field of science and equipment where monitoring of internal structure of materials is required. The use of this method is of special interest for restoration of internal structure of the material subjected to the microwave oven processing.
The method is based on the use of mathematical apparatus of the artificial neural networks (ANN). The method is based on simple measurements of parameters of a matrix of dispersion (coefficients of reflection and passing) of the waveguide system containing the research sample with the subsequent application of ANN trained on data of numerical modeling of electromagnetic system. The measured parameters are coefficients of reflection and passing of two-port waveguide system.
During modeling of measuring system, the training sets (couple of entrance and corresponding to them output data sets) are generated as random data set. Then, every time, a matrix of dispersion of turnstile connection is calculated. After completion of modeling, we receive a numerical data set which will be used for training of a neural network.
After the neural network is rather trained, it can be used for restoration of parameters of a cubic sample by results of measurements of coefficients of reflection and passing of the electromagnetic field in ports of measuring system.
Quality of training of a neural network is estimated by a value of the relative error of reconstruction calculated for a test data set pro-vided that test pairs of input and output parameters aren\'t included into the training set (a numerical data set on which ANN was trained).
To illustrate the performance of the proposed method, the paper presents numerical results of the reconstruction of parameters of cubic samples consisting of mix of particles of solid material of a rectangular or cylindrical form with air. The restored parameters of material can be determined with the use of elementary electromagnetic measurements in simple waveguide system with the relative error, which isn\'t exceeding 5%.
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