The development of an automatic system for installing a magneto-optical magnetic field sensor in a neutral position has been carried out. Installation in the neutral position is carried out by an automatic piezoelectric drive control system based on a microcontroller. A mathematical model is constructed and numerical simulation of the automatic control system is performed. The results and parameters of the simulation are presented. The developed system provides a significant increase in the autonomy of the sensor, which makes it possible to eliminate or significantly reduce the cost of regulating the sensor.
Keywords: magnetic field sensor, magneto-optical sensor, automatic control system, piezo motor
The article deals with modern research in the field of decision support. A model of distributed processing of requests by agents of decision support systems is proposed. The main components of the model are considered. An algorithm is built on the basis of the proposed model. A step-by-step description of the algorithm's actions is given. The main planned results have been identified.
Keywords: decision support systems, intelligent agents, request processing, decision support model
The article provides a solution to the problem of optimizing the frequency of maintenance on the example of the frame of a KamAZ-4308 truck. As an optimization criterion, it is proposed to use unit costs for a given time, including the costs of eliminating hidden failures. The calculation of the frame resource is carried out, the empirical and approximating functions of the general population of the finite volume are obtained.
Keywords: car, probability of uptime, maintenance, optimization, unit costs, reliability assessment
The article discusses the problems that arise in pattern recognition related to clustering and data abstraction. Detailed typical data clustering options. The problem of data transformation by vector quantization with the least error is given. A competitive training system for an artificial neural network based on a growing neural gas is described. Using the method of growing neural gas, an improved algorithm of a self-learning artificial neural network of competitive training is proposed. The criteria for completing clustering using the adaptation criterion as a stop criterion are defined. Examples of data clustering by an artificial neural network using the method of growing neural gas are given.
Keywords: clustering, artificial neural network, computer modeling, pattern recognition, self-learning intelligent systems
The article is devoted to the study of the thyristor regulator of the booster voltage harmonic composition in the mode of longitudinal-transverse regulation. The results of the harmonic analysis of thyristor regulator output voltage , obtained using simulation in the Simulink package, are presented.
Keywords: longitudinal-transverse regulation, thyristor regulator, regulating characteristics, modeling, harmonic analysis, Matlab Simulink
In this paper, a numerical study of the optimized body shape with minimal aerodynamic drag has been carried out. A computational experiment involves the transition from the study of a real object to the study of its mathematical model, for the study of such processes, a full-scale study of which is impossible, for some reason is difficult or expensive. The conditions for comparing the forms of bodies in a computational experiment are that they are kept constant for all bodies: the volume and shape of the working area; distances from sources, drains and centers of bodies; gas flow rates; body mass and other secondary characteristics besides just the very shape of the surface.
Keywords: aerodynamic resistance, optimized body shape, numerical simulation, computational experiment, temperature field, convective heat transfer
In this paper, an analysis of the problems and tasks arising from the design of situational awareness tools has been carried out. As a result, it has been established that the approaches in this area do not satisfy the requirements for modern intelligent tools for operational decision support for the reasons for the lack of methods and tools reflecting the dynamics of information processes and a distributed information processing architecture with weakly structured properties. The methods of operating and extracting knowledge from semistructured dynamic information are proposed.
Keywords: Situational awareness, poorly structured data, temporal information, dynamic structures, intellectual analysis
In this work, a study was made of the efficiency of the heat sink surface of a volumetric body with an internal heat source. An electrostatic analog of the distribution of the thermal field is chosen. A model of the convective flow is proposed, under certain initial and boundary conditions, the thermal conductivity of the medium transforming into heat removal. The conclusion is made about the ineffectiveness of the heat-conducting surface in the form of whip, finned and other designs of existing heat sinks, increasing only the mass, technological complexity of manufacture, thermal resistance and temperature of the heat-loaded element.
Keywords: Temperature field, convective heat transfer, effective heat sink area, electrostatic analog, similarity theory
The paper presents the development of a system for detecting the status of control and protection system drives (CPS) of a water-water power reactor by vibration signals using the frequency components method. Results of experimental researches at the "Izhorskiy Plant" PO are given. Spectral analysis is used to isolate the frequency ranges of the CPS diagnostic signal spectra, and to develop diagnostic standards. The work describes formation of reference diagnostic vectors (a set of diagnostic features in the form of a binary code) and their comparison with the current state. The developed standards formed the basis for the system of automatic recognition of the object state. The introduction of such a system will simplify the task of collecting, analyzing, comparing drives data during operation at nuclear power plants, as well as improving methods of testing and diagnosing CPS drives, which should positively affect the reliability and resource of equipment.
Keywords: CPS drive, technical diagnostics, spectral analysis, diagnostic vector, state recognition
The paper proposes a method for determining the leakage in the gate of an electric drive armature by sound and ultrasonic signals using the Shannon and approximation entropy indices. The results of equipment diagnostics in laboratory and industrial conditions are presented. The results indicate the possibility of using entropy indicators as sensitive diagnostic features.
Keywords: electric drive armature, ultrasonic diagnostics, Shannon entropy, approximation entropy
The assessment of the quality of the production of works on the construction of the upper layers of the road cover by the destructive and non-destructive method is considered, both methods are compared by searching for the main advantages and disadvantages. The order and the scheme of the production of each of the estimates are described.
Keywords: motor roads, quality assessment, road facilities, gamma density meters, electromagnetic (dielectric) densitometers, radioisotope densitometers, densitometer
The problem of selection of diagnostic signs is solved by methods of statistical, spectral and entroic processing of signals and the logical analysis of their results. Results of data processing allowed to choose the most efficient characteristics (diagnostic signs) of signals providing separability of signals in the chosen priznakovy space i.e. classification. The problem of algorithmization of diagnostics of electrodrive fittings (further EPA) is solved as a problem of a pattern recognition of five classes of a condition of EPA on the basis of comparison of the current Boolean combinations to seven standards.
Keywords: electrodrive fittings, spectral analysis, entropy of Shannon, permutation entropy, basic vector, pattern recognition
In this paper, the temperature distribution from a point source of heat under convective heat transfer is studied. The Navier-Stokes equation describing the steady two-dimensional laminar motion of a fluid is solved numerically. The distribution of the temperature field of a heat-loaded point source is obtained under appropriate boundary conditions, supplemented by the boundary conditions for the flow velocity to equal zero on the paraboloid walls by numerical integration using the control volume method.
Keywords: Radiator protrusion shape, thermal conductivity, thermal apparatus mode, the temperature of the heat source
In work on the basis of one of the methods of nonlinear acoustics (method of successive approximations) is considered environment as a set of orthogonal plane layers. The analysis is conducted with the division generated total field into components parallel and orthogonal to the direction of its propagation. It is recognized as the primary distribution field distribution along the longitudinal direction with the introduction of the aperture factor and orthogonal to the introduction of the cross-aperture factor. It determines the range of changes of the parameters for biological environments in the case of the nonlinear interaction of acoustic waves in them.
Keywords: nonlinear interaction, quadratic nonlinearity, different layered media, immersion method, transverse aperture factor.
One of the parameters determining the efficiency of cleaning the blood in hemodialysis therapy is an effective mass transfer processes of metabolites through the dialyzer, which is defined by the mechanism of molecular diffusion and convection of low and medium weight substances in the blood. The article presents an analysis of modern mass transport models: streaming and kinetic; the analytical expressions of the spatial and temporal distribution of metabolites in the dialyzer. The results of mathematical modeling showed that these models do not reflect the full extent of the entire mechanism of mass transfer and must be supplemented. This is primarily due to the fact that blood is a non-Newtonian fluid. In addition, during hemodialysis, there is a change of the rheological properties of the blood - viscosity aggregated and deformability of erythrocytes, which ultimately affects the dialyzer mass transfer processes, reduces its clearance and thus reduces the efficiency of hemodialysis. The authors consider that the solution to this problem might be to develop a space-time mathematical model of mass transfer (the so-called distributed model of mass transfer), built with the influence of the driving forces behind the transfer of substances through the membrane dialyzer basic parameters and characteristics of fibers and rheological blood properties. In our view, the space-time dependence of the distribution of concentrations of metabolites in the blood and dialysate hemodialyzers allow to predict normalization the concentration of metabolites in the blood, and thus improve the accuracy of assessing the quality of dialysis.
Keywords: hemodialysis, mathematical modeling, spatial distribution, the time dependence, the space-time model