ISSN 0021-3454 (print version)
ISSN 2500-0381 (online version)
Summaries of the issue


A system of verification of the computing process in information system is proposed. The study relevance is determined by the demand for reliable, correctly functioning information systems and insufficient verification of such systems. Computing process verification has not been applied to information systems before. The computing processes in information system, as well as the main blocks of the information system "Conference" are considered. Applied graphical-analytic and software models check the main points of verification of the computing process. The use of the developed computing process verification system for the web-oriented information system "Conference" is considered.


The use of a well-known method for calculating a digital tracking system with a minimum time of complete attenuation of a free process in the presence of a net delay time in a direct circuit does not allow the correction device to be physically implemented. The adaptation of the calculation method to the case under consideration is based on the preliminary determination of the minimum attenuation time of the free process. This made it possible to reduce the order of the numerator of the desired transfer function of the closed digital tracking system to the order of the numerator of the transfer function of the continuous part of the system and to ensure the physical implementation of the correction device. The minimum transition time of the digital tracking system is shown to increases by the time of the net delay t in the forward circuit, and the speed error increases by an amount equal to the product of t and the tracking speed. It is proved that the choice of the numerator of the desired transfer function of a closed digital tracking system equal to the numerator of the discrete transfer function of the continuous part, not only simplifies the correction device and ensures the digital tracking system "roughness", but is also a necessary and sufficient condition for the exclusion of "hidden oscillations" after the total attenuation of the discrete transient process. The proposed calculation method is compared with the method based on the use of the Smith predictor. An example of calculating a digital tracking system with a net delay in a direct circuit is considered. Its digital modeling was carried out in the MatLab system when working out linearly increasing and discontinuous setting effects, which confirmed the minimum attenuation time of the free process and the calculated value of the velocity error.


The structure of a multilayer neural network of direct propagation, designed to determine the motion parameters of the mass center of a non-cooperating orbital object by results of measurements carried out by a spacecraft optical-electronic system, is substantiated. The orbital object zenith distances at characteristic points of the spacecraft's orbit and the time of the orbital object's passage between these points were chosen as the measured parameters. The shortest duration of training for a given accuracy of determining the of the orbital object's center of mass motion parameters is determined. The presented results can be used in justification and development of systems for autonomous determination of the parameters of motion of the orbital object center of mass based on a spacecraft onboard optical means.


The aim of the work is to improve light microscopes for biological research, which record images on CCD detectors, providing operation without time spent on optics refocusing. The prospects and relevance of the development of high-aperture microscope objectives with an enlarged field of view, operating in conjunction with a matrix CCD image detector, are shown. A high-aperture wide-field microscope objective has been developed, its optical characteristics are given, and the optical scheme is demonstrated. Evaluation and calculation of tolerances for subsequent manufacturing by the Monte Carlo method are carried out.


The problem of filament burr in 3D printing devices is analyzed, a review of existing solutions is carried out, and an original method for automatic detection of scoring is proposed. The proposed method for automating the detection of filament burr in 3D printing devices can provide material savings, equipment safety, and reduce time spent on readjustment and repair of devices due to the timely termination of the emergency process, which as a result guarantees the stability and reliability of the production technology.


Two variants of the device containing four or six small-sized magnetic induction sensors mounted on the sole of the rail are considered. The device is designed to diagnose the shape of the crest of rolling stock wheelsets during its movement over the sensors along a straight rail track. An algorithm for calculating the parameters of the profile of the wheelset ridge is proposed, which allows identifying the coordinates of the center and the radius of the ridge with the shape described by a second-order equation, i.e., the model of the crest tire has the shape of a semicircle corresponding to the standard wheel profile. In addition, an algorithm for testing the adequacy of the obtained parametric model is implemented. An algorithm for identifying the degree of wear of the vertical undercutting of the ridges of the wheelsets is proposed based on the use of approaches similar to instrumental control methods, using standard templates specially developed in accordance with the State Standard "Solid Rolled Wheels". The proposed mathematical model describing the process of wear of the vertical undercutting of the ridge makes it possible to automate the procedure for diagnosing the state of the wheel pair profile during the movement of the train over the three-point system of magnetic induction sensors and simulating the procedure for instrumental control of the wheel crest parameters. The algorithms embedded in the proposed mathematical model and implemented on the basis of a microprocessor controller allow automating the process of instrument monitoring of the condition of wheel ridges in real time, calculating and predicting the timing of maintenance or necessary repair of wheel sets of railway transport rolling stock.
It is shown that not all mathematical models used to estimate the time of the technological run of telecommunication equipment take into account the design and technological features of the hardware. The statistics of failures of telecommunication equipment are given, proving the need to take into account these features. It is shown that the simultaneous influence of factors such as ambient temperature, on/off cycling, relative humidity, supply voltage or current leads to an acceleration of the technological run by thousands of times. A technique has been developed that allows to significantly reduce the time of technological run-through and confirmation of the service life of the electronic module of the first level of telecommunication equipment. The advantages of the technique are the use of a multifactorial forced mode to assess the required acceleration coefficient, as well as taking into account factors that significantly affect the state of telecommunications equipment. The advantage of the technique lies in the differential prediction of reliability indicators of telecommunication equipment and in the possibility of reducing the number of failures during its normal operation, which is proved by the results of experimental research carried out.
STUDY OF THE LATEST DENTAL MATERIALS BY STRETCHING TO OBTAIN THE TENSILE STRENGTH PARAMETER Ludmila I. Shalamay, Elena Yu. Mendosa, Majorov Evgeniy E., Victoria B. Lampusova, Оксас Н. С.
The latest dental materials are tested by stretching to obtain a tensile strength parameter. The safety of restorative composite materials on the hard tissues of the tooth is ensured by mechanical parameters, so the work is promising and relevant for therapeutic dentistry. For different composites, the tensile strength parameters were obtained using the IM-4R automated tensile testing machine. The strength parameters were measured on thirty specimens where the cross-sectional area of each specimen was 5 mm. The results of measurements of the dependence of strength on the number of dental composites are represented by polynomials of the third degree; the values of approximation reliability are determined.