Using a device of close homogeneous exponential queueing networks (QN) a mathematical model of an distributed information system functiouning for solving the problem of getting integral indexis on the basis of local computing network on the basis of three- level client server arhitecture. The base correlation for transitione matrix probabilities constraction and intensitiese of service at the network nodes are given.The peculiarity of the model being worked out is in making a selective choice of information at the database servers and via the channel of communication not the full data base is transmitted but some separate parts of it, which satisfy the conditions of SQL-request search.
Keywords: Distributed information system, distributed data base, local computing system, mass service network, conceptual model, exponential law of distributing the random value, stationary probability, mark process, the global balance equation, system reaction tim
This article describes the stages of implementing the program to solve the task of calculating the average response time of a distributed information processing system to user requests and an algorithm for the optimal distribution of information relations over the nodes of a distributed information processing system implemented on the basis of a file server architecture and a two-tier client server architecture, with and without locks. The procedure for constructing the initial data for modeling is described: the elements of the matrix of the initial distribution of information resources (relations) over the nodes of the distributed information processing system, the elements of the matrix of information interrelation between the requests of users of the distributed information processing system and the information resources themselves, the elements of the matrix of probabilities for generating queries by users. A procedure has been developed and programmed to significantly simplify the calculation of the normalizing constant, and accordingly the average response time of the system to user requests. The results of numerical experiments are presented
Keywords: Distributed information processing system, file-server architecture, two-level client-server architecture, nonlinear combinatorial optimization, generator of equiprobable choice, Jordan-Gauss method, normalized constant, average reaction time of the syste
The presented work is devoted to mathematical model operation of the clinoid support (a slider, a guide) working on micropolar fluid lubricant in the turbulent mode of a sliding friction taking into account dependence of viscous characteristics of mikroprolyarny lubricant on temperature and pressure. We consider for a case of ""lamina"" a set of equations of driving of thick incompressible liquid of micropolar lubricant taking into account dependence of viscous characteristics of mikroprolyarny lubricant on temperature and pressure, an equation of continuity and a formula of speed of a dissipation of energy for definition of the function Ф (х) caused by a melt of a surface of a basic ring. The main performance characteristics of the considered couple of sliding friction are as a result defined. Influence of parameter which is caused by a guide melt and also dependence of structural and viscous parameters of micropolar fluid lubricant on temperature and pressure upon a carrying capacity and a frictional force is estimated.
Keywords: hydrodynamics, a sliding support (a slider, a guide), viscid incompressible fluid micropolar lubricant, the melted guide surface, dependence of viscosity of lubricant on pressure and temperature
In the paper, on the basis of the equation of motion of an incompressible lubricant having the micro-polar properties for the case of a ""thin layer"", the equation of continuity, Darcy and the formula for the energy dissipation rate for determining the function Ф (θ), caused by the molten surface of the bearing bush covered with a low-melting metallic melt of a carrier asymptotic solution by the thermal parameter K. Using a self-similar solution for the zeroth approximation, i.e. without taking into account the melt of the low-melting metallic melt, and for the first approximation, taking into account the low-melting metallic melt, the velocity and pressure fields in the lubricating and porous layers are determined, and the basic performance characteristics of the radial slide bearing are determined. The characteristic permeability of the porous layer and the melt of the surface of the bearing bush, coated with a low-melting metallic melt, on the load capacity and frictional force are estimated.
Keywords: low-melting metallic melt, porous layer permeability, lubricant with micro-polar properties, sliding bearing
The article is devoted to the development of a multicriteria transport problem solution. As criteria, the minimal cost of transportation, the minimal time of transportation, the minimal overhead charges and the maximal volume of transportations were taken. Classical methods for solving multicriteria optimization problems are modified and adapted to the transport problem specification. In Visual Studio C # programming language, is used as a software package to solve the multicriteria transport task problem by one of the methods of linear convolution, or the main criterion, or compromise method or the method of guaranteed result and to compare the results obtained. The first paragraph is devoted to the formulation and mathematical model design of four-criterial transport problem. The second paragraph contains an example the application of guaranteed result method to solve transport problem. The next paragraph describes the program realization of transport problem with four criteria.
Keywords: four-criterial transport problem, method of potentials, initial symplex table, main criterium method, compromise method, lambda-problem, liniar convolutuin method, transporat carriages, program realization, multiplicative convolution, guaranteed result me
Set out the main stages of development of the automated system of operational control in railway transport, the issue of the effectiveness of this system. Describes methods to improve efficiency, a model of the processing of information flows
Keywords: automated system of operational control in railway transport, road-network database, a table of the current status information message, the transport system, thematic table, efficiency, rail transport
In the article is considered the minimax problem solving. This is a characteristic problem of the schedules theory. As a possible method for solving this problem, a modified Goldberg model is considered, which is one of the varieties of genetic algorithms. The efficiency of this model is described on the results accuracy estimate, obtained by using a standard crossover for various types of mutations and parameters of the genetic algorithm.
Keywords: single-point crossover, genetic algorithm, modified Goldberg model, mutation, minimax problem, scheduling theory, elite individual, individual, generation
The article discusses the development of a mathematical model in the deterministic form of recording the main dependences that determine the process of vaporization in a steam power plant to produce heat and electricity when used as a source of biofuel energy. Theoretically, the parameters of the working process of the installation were calculated; thermal efficiency of the turbine; heat useful used in the boiler unit; the efficiency of the boiler; the percentage of heat loss with exhaust gases; the estimated hourly consumption of solid biofuel; the annual amount of heat obtained by burning the mass of crop residues; the theoretical combustion temperature of crop residues; the actual steam velocity in the Laval nozzle; the heat loss in the nozzle, etc.in the course of calculations with the help of a multi-factor experiment, the parameters and the shape of the turbine blade used in the installation were obtained. Using the presented mathematical model given in the article and the data of the Federal state statistics service, we obtain the numerical values of the working process of the installation working on biofuel. For convenience, all the summary theoretical data of the numerical values of the basic theoretical dependences of the mathematical model of the working process of the layout of the steam power plant for heat and electricity was included in the table. Thus, theoretical studies show the possibility of producing electricity of the required quality using straw to produce high-pressure steam.
Keywords: mathematical model the working process of the pressure volume, a steam turbine,producing heat and electric energy, biofuels
In this paper, we study the frequency dependence of the inductor with a ferromagnetic core in the sound frequency range. Based on the measurements made, a replacement circuit for the coil is constructed, taking into account the active losses due to magnetic hysteresis, as well as the capacitive component of the current appearing at higher frequencies. The method of determining the parameters of the substitution scheme is given in the article, which, due to the complexity of the mathematical model, was determined by statistical averaging of the solutions of systems of nonlinear equations. Conclusions are made about the practical application of this substitution scheme in electronic devices.
Keywords: substitution scheme induction coil, frequency dependence of the impedance of the induction coil, active losses in the core
The article reports about approximation algorithm for Integer Factoriation Problem (IFP) using reduction to optimizing case of SAT problem with 3 literals per clause (MAX-3SAT). A continuous functional that equivivalent MAX-3SAT is builded and solved by simple iteration method with variable neighboordood search and Bayesian rounding. It shown that global minimum of the functional cannot be reached in almost samples because local extremums but arguments of ones can be compared with the exact solution. The experiments show that the developed gybrid algorithm improves earlier version developed by authors. Also this method is analyzed by quantum channels defense In systems of quantum key distribution. A typical structure of one is described.
Keywords: Integer Factorization Problem, an optimzed version of SAT problem (MAX-3SAT), various neighboorhood search, continuous functional of MAX-3SAT representation, quantum key distribution
The shock interaction of the links of the mechanism of the cable trimming machine on the example of the model of "oblique" impacts is considered in the article, when shock impulses arise between the links not only along the impact line, but also in a tangent to the colliding surfaces of the plane. It is shown that the resulting significant pulses between colliding elements contribute to the creation of wave processes in long bodies. Such processes, due to their transfer to the tubular bodies of the spindles, give rise to acoustic fields
Keywords: noise generation, vibroacoustics, vibration damping, noise control, noise emission
Passive detection sensors are widely spread in engineering-technical systems of information protection. During designing such systems, it may be difficult to calculate the coverage areas of infrared detectors. This is due to the fact that the problem of establishing a relationship between the theory of statistical detection and the choice of parameters for the equation of the maximum detection range is not considered in detail. In this regard, the task was to develop a method for applying the basic equation of passive location to calculate the coverage areas of infrared detectors. The calculation method is developed on the basis of the equation of the maximum range of the passive receiver. The study considered three models of the signal-to-noise ratio: a signal against a white noise background with fully known signal-to-noise parameters; detection of a signal whose phase and amplitude are unknown; and detection of a random signal against a noise background. As a result of the research, the conditions under which the passive signal detection formulas on the background of noise give correct results were found. Thus, the connection of the statistical theory of detection with the equation of the range of the passive emitter was established.
Keywords: information security, infrared detector, passive location, engineering and technical protection, the pyroelectric element
In the article on the basis of the analysis the basic technical and organizational actions are defined that allowed to carry out statement of a task on improvement of system of management of technological process of portal car wash. A mathematical model of fuzzy car wash control is developed due to the program control of water supply depending on the shape, geometry and degree of pollution of the car, in order to reduce water consumption and improve the energy efficiency of the portal car wash. Mamdani algorithm is proposed as fuzzy inference algorithm, which is easily implemented in MATLAB software product on the basis of knowledge and experience of experts, as well as modeling of the operator. Formalization of the description of water supply level, shape, size and degree of pollution of the car is carried out by means of linguistic variables, their type and description of elements of thermal sets of these variables is given. The proposed mathematical model can be used in the design of control systems and other types of automatic car washes.
Keywords: car wash, mathematical model, fuzzy control, fuzzy inference algorithm, linguistic variable, term-set of linguistic variable, basic set
In this article to solve the problem of optimal distribution of information resources over the nodes of distributed inorganic system according to the criterion of minimum of the medium time, the response of the system to the requests of the users an original heuristic algorithm is proposed that uses the notion of databases as points of a mulltidimensional space, but about nodes in which these bases are placed as clasters. The resuts of numerical experiments are presennted depending on the architecture of the distributed system used and on the method of ensuring data integrity. Numerical experiments showed rather high efficiency of the proposed algorithm.
Keywords: Distributed information system, distributed data base, local computing system, mass service network, non-lineare combinatorial optimization, query generation, a matrix of probabilities for generating queries by users, a matrix for distributing relations a
The article once again highlights the problem of injury growth in our country. The article presents the developed digital jumpsuit for work at height, excluding the possibility of violation of the rules of TB, controlling the integrity of the belts. It is concluded that human security, his life can not be given to him only in a rapidly developing technogenic society, a person should actively help digital technology
Keywords: poor working conditions, simple protective measures against the fall of man, fiber optics, probability, risk, and digital technology
The econometric analysis of GDP per capita in the Russian Federation is being given. The number of the departured people from the Russian Federation, nominal average charged wages and exports volume are used as the exogenous variety. The received model of the multiple linear regression is being studied for quality.
Keywords: gross domestic product, GDP per capita, econometrics analysis, multiple linear regression model, endogenous variety, exogenous variety, heteroskedasticity
Optimal usage of territories appears as applicable problem at the present time. Its description is hold in geographic information systems (GIS) and may be used for solving ecological, administrative, transport and logistical tasks. We consider to use topographic maps for production GIS. By now algorithms for reconstruction of plan of contour lines are developed. This plan of contour lines appears as matrix of spatial scattered data, which are needed to interpolate for production a digital terrain model. There are some common algorithms for interpolation (linear, cubic spline, natural), but they aren’t fit for good shape reproduction. We consider an algorithm based on 3-class classifier of points. Points of 1st class are between two contour lines and are interpolated by n nearest points of the nearest contour line and the nearest point of another line. Points of 2nd class are inside of one contour line, accord with peaks or depths and are interpolated with similar algorithm and value of extremum which is taken by mark of height is used. Points of 3rd class are between a contour line and boundaries of topographic map; their interpolation may be taken by union of several maps and they become points of 1st class. Processing speed, maximal error and mean-root square error are used as measure of quality. Considered algorithm has shown improvement by comparison with other methods with decrease of errors and nonthreatening increasing of processing time.
Keywords: interpolation, geographic information system, topographic map, digital terrain model, scattered data
In this paper we consider the problem of constructing a precise passability model by point cloud obtained from stereo cameras. To solve this problem, we used a hierarchical elevation map. The criterion for dividing cells into smaller ones was extended to take into account the cell's completeness with a limited field of view. The passability model was also supplemented with an algorithm for detecting step obstacles. The accuracy and completeness of the detection of obstacles and a free surface was calculated experimentally on dataset taken in real conditions. The result of the experiment shows that the proposed approach increases the number of detected obstacles without significant loss of accuracy.
Keywords: passability model, elevation map, obstacle detection, stereo vision, principal component analysis
An analysis of the mechanisms limiting the growth of the output characteristics of ion recombination He-Ca lasers with an increase in the active medium volume and frequency of pulse repetition is carried out. It was established that by a growing laser tube diameter and a growing frequency of pulse repetition the average power of He-Ca lasers saturates and then decreases due to the formation of radial non-uniformity of the active medium as a result of its overheating on the axis and of the radial cataphoresis, as well as because of the raise of the electron temperature level in early afterglow, conditioned by the grow of gas temperature. It is pointed out that as possible ways of increasing the output characteristics can be used the blackening of the laser tube surface, the use of an independent input of calcium vapours, the use of a forced cooling, while the application of a tube with rectangular cross-section will allow to maximally increasing the energy characteristics. Based on numerical computations it is shown that the attainable maximum of running power of He-Ca lasers amounts to: ~ 4.4 W/m for self-heating active elements from BeO-ceramics and ~ 5.2 W/m – on blackening their surface; ~ 5.3 W/m for an independent calcium vapours input and ~ 6.2 W/m – for its combination with blackening; ~ 9.5 W/m for an intensive forced cooling of active elements with cylindrical geometry; ~ 16 W/m – with active elements of rectangular cross-section at a ratio of wall sizes 1:3.
Keywords: metal vapor laser, the ion recombination He-Ca laser, pulse-periodic discharge, gas-discharge plasma, self-heating regime, mathematical modeling
Theoretical studies of the temperature distribution during laser heating of the TiO2 precursor film on the FTO/glass substrate have been carried out. The simulation was performed on the basis of a numerical solution of the heat equation in the Matlab program to determine the energy density of the laser radiation necessary for crystallization of TiO2. It was shown that on the surface of the TiO2 precursor the temperature reaches a maximum value at a time point of 133 ns with the Gaussian temporal form of the laser pulse. The optimum energy density for crystallization of the TiO2 precursor film with the nanosecond pulse duration is 1.3-1.6 J/cm2, when the film thickness temperature corresponds to 400-500 °C. The obtained results of the simulation are consistent with experimental studies.
Keywords: numerical simulation, laser heating, temperature distribution, TiO2 film, solar cell
The paper contains the results of investigation of effectiveness of application of various models oriented towards interval time series (ITS) to forecasting behavior of gas distribution networks (GDS) parameters involving the real data obtained during the process of their continuous control. The necessity of taking into account the factor of seasonality caused by periodic fluctuations in the level of the corresponding variable is justified. A comparative analysis of the properties of the special interval modification of the model based on exponential smoothing, neural network and hybrid prediction models in relation to the ITS with seasonality is performed, their merits and demerits are noted.
Keywords: interval-valued time series, exponential smoothing model, neural model, long short-term memory, hybrid model
The article suggests a technique for automatic segmentation of satellite images on the basis of convolutional neural networks into several classes, such as buildings, rivers, roads, etc. The software implementation of the proposed methodology took the second place in the competition for the segmentation of satellite imagery on the Kaggle platoform in competition: Dstl Satellite Imagery Feature Detection. The article describes how to prepare images for the training of neural network and reveal details for full dataflow and the principles of the traning. The structure of the neural network for segmentation is proposed. The network is built on the basis of UNET with additional BatchNormalization and Dropout layers, based on double convolution blocks. A procedure for cross-evaluation is described to assess the accuracy of the models obtained. The descriptions of algorithms for postprocessing and the technique of segmentation refinement are presented by using an ensemble of several models. A specialized model is proposed for finding objects of small size, such as "cars" and "motorcycles". An overview of other methods used to solve this problem is also given, which were not included in the final solution. In the experimental results it is shown that the efficiency of neural networks in this task is extremely high and it is possible to automatically prepare a layout of the terrain similar to the markup made by human. And thereby it allows to save money, since significant financial resources are being spent on manual marking.
Keywords: convolutional neural nets, sattelite imagery, image segmentation, machine learning, crossvalidation, Jaccard coefficient, UNET network, image classification, computer vision, contest results
Examples of bearings with hydrodynamic wedge are mapped to specific features of the incompressible lubrication (drip liquid) and compressible (gas). Due to the physical nature of the processes occurring in the gas lubricating layer. The main advantages of axial and radial gas dynamic bearing with spiral mikrokanale, which was the most widely and effective used not only as bearings, but also as the best contactless seal.
Keywords: lubrication layer, hydrodynamic wedge, pressure, load capacity, helical grooves, optimal parameters
The article deals with the movement of erythrocytes along the narrow capillaries with a diameter smaller than the erythrocyte diameter. Red blood cell in narrow capillary has tank-treading motion. The erythrocyte rotation frequency reaches several dozen revolutions per second. Electric charges located on the surface of the erythrocyte, move together with the erythrocyte membrane and create a magnetic field in the surrounding space. A two-dimensional model of erythrocyte movement along narrow capillaries was constructed. If the erythrocyte surface area and erythrocyte charge are known, then the density of charges on the erythrocyte membrane can be determined. The magnetic field strength of a moving charged particle can be determined if the particle charge, the particle velocity, the distance from the particle to the point at which the magnetic field strength is determined, the angle between the direction of the particle velocity and the direct connecting particle, and the point at which the tension is determined are known. The total strength of the magnetic field of several moving charged particles is defined as the vector sum of the magnetic field strengths of the individual moving charged particles. In the two-dimensional model it is assumed that the red blood cells are rectangles that move along the capillary, and the erythrocyte membrane is the sides of the rectangle. Discrete charges are located on the sides of the rectangle and move either clockwise or counterclockwise. It is possible two variants. Their membranes either rotate in the same direction or in opposite directions. Calculations were carried out for both variants and at different rates of rotation of erythrocyte membranes (from 0 to 50 revolutions per second) and distances between red blood cells. It is shown that at distances between erythrocytes smaller than the two capillary diameters, the influence of neighboring red blood cells can be neglected (the difference is less than 3%).
Keywords: "mathematical model, magnetic field, erythrocytes, narrow capillaries, magnetic field strength "
In this article, we briefly reviewed the problem of image quality loss. Methods for restoring defocused images are considered and analyzed. Describes lubrication functions and ways of defocusing the image, as well as a mechanism for eliminating the three main types of image blurring. A number of experiments were conducted on the defocused images. An algorithm for deconvolving an image using a Wiener filter and using the Tikhonov regularization method is disassembled. The analysis of the efficiency of the Wiener filter and Tikhonov regularization for blurred images is performed. The comparative analysis was carried out using the developed software for the restoration of defocused images in the Microsoft Visual Studio 2012 environment. For the Fourier transform, the library was used - aForge. A certain dependence of the execution time of the algorithm on the size of the image to be reconstructed. It is established that on the tested problems - the time complexity of the Wiener filter is 1.1 times less than the time complexity of Tikhonov regularization.
Keywords: Wiener filter, Wiener deconvolution, Tikhonov regularization, image reconstruction, blurred images, motion blur, Gaussian blur