Table of Contents

  • THEORETICAL FOUNDATIONS AND SPECIFICITY OF MATHEMATICAL MODELLING

  • MATHEMATICAL MODELLING OF TECHNOLOGICAL PROCESSES AND SYSTEMS

    • P-BOX UNCERTAINTY QUANTIFICATION OF QUEUES USING THE TAYLOR SERIES EXPANSION

      pg(s) 83-85

      In this work, firstly we opted, for the global sensitivity analysis using the first order Sobol indices of simulated by the Monte Carlo method, to see and determine the parameters to which the stationary distribution of model GI/M/1/N with negative arrivals is sensitive. Secondly, we used the Monte Carlo method to propagate the uncertainty of the parameters of the stationary distribution of GI/M/1/N queuing model with negative arrivals, while estimating its statistics (expectation and variance).

    • THE FORMATION OF INVESTMENT PORTFOLIOS BASED ON FORECASTED INCOME WITH THE USE OF FRACTAL MODELS

      pg(s) 86-88

      The article proposes an approach to the formation of optimal investment portfolios according to the criteria of profitability and risk based on the predicted returns of assets obtained using fractal econometric models. It has been hypothesized that this method allows you to create more profitable and low-risk portfolios than in the optimization of historical returns. To test the approach and test the hypothesis, an attempt was made to form various portfolio options from the shares of two Russian issuers. The results obtained allow us to conclude that the proposed approach is promising, and further research is needed.

    • THEORETICAL MODELING OF THE MAGNETIC STATES OF SYNTHESIZED FE3O4 – FE3-XTIXO4 PARTICLES

      pg(s) 89-92

      A system of two-phase particles (Fe3O4 – Fe3-xTixO4) has been obtained using the sol-gel method followed by hydrothermal treatment. It is shown that the synthesis conditions favor forming composites that contain titanomagnetite in very low concentration. A theoretical analysis of the magnetic properties of system was performed using the model of clusters consisting of magnetostatically interacting particles. The theoretical value of the saturation magnetization and the experimental values of the coercive force can be explained by the presence of two different magnetic phases.

    • DESIGN AND ANALYSIS OF A NOVEL SEALING UNIT FOR PACKING MACHINES

      pg(s) 93-96

      Packaging machines using for wet wipes operate at high speeds and the demand for speed in the relevant market is constantly increasing. The most important difficulty to faster operation of these machines is the relative slowness of the units used for sealing the packages. In this study, it is aimed to design a unique mechanism that can work at 160 packages per min instead of sealing unit which is still operating at 120 packages per min, and to verify the design by mechanical analysis. For this purpose; instead of the existing sealing unit driven by a single servo motor, the horizontal and vertical movements are separated and driven by two servo motors to achieve %33 more speed.

    • MATHEMATICAL REPRESENTATION OF A CFD MODEL FOR ARTIFICIAL FOG SPRAY INVESTIGATION

      pg(s) 97-100

      We present and explain the mathematical apparatus used in a numerical simulation model created with АNSYS СFX Software. The purpose of the model is to perform computations of fog parameters in different points of artificially generated fog sprays, which are then used to calibrate a novel type of fog sensors. By changing the distance between the nozzle and the measuring laser beam of the sensor, we can assess how the number flow rate and diameter distribution of fog droplets are varied within in the spray. This work is related to improving European security by introducing systems for quick counteraction to terrorist attacks, industrial accidents and natural disasters. These systems use artificial fog generation to collect and deposit on the ground harmful aerosols dispersed in air, especially CBRN agents. Our newly developed fog sensors operate on the basis of the electromagnetic echo effect to control the decontamination process. In order to optimize the work of the sensors, it is crucial to investigate fogs and their ability to absorb harmful substances from air. The most important fog parameters that influence the efficiency of the cleaning process are the number of droplets and their size.

    • MATHEMATICAL AND NUMERICAL SIMULATION OF STRESSES AND DISPLACEMENTS LOCALIZATION PROBLEMS

      pg(s) 101-104

      Mathematical and numerical simulation of the non-classical problems, namely problems of localization of stresses and displacements in the elastic body, are obtained by the boundary element method. The current work examines two localization problems, which have the following physical sense: on the middle point of the segment lying inside a body parallel to the border half plane in first case a point force is applied, and we must find such value of the normal stress along the section of the border half plane, which will cause this point force, while in the second case, there is given a vertical narrow deep trench outgoing of this point, and we must find such value of the normal stress along the section of the border half plane, which will result in such a pit. By using MATLAB software, the numerical results are obtained and corresponding graphs are constructed.