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  • Research of a multicriteria problem оf decision about selecting a franchise to investment by using method of Fuzzy VICOR

    For a decision maker, the problem is to choose the best franchise on a wide variety of existing Russian and foreign alternatives in the face of uncertainty. For a successful business, a decision maker needs to analyze the data on all the criteria among the selected franchises. In this paper, 5 alternatives- franchises of linguistic centers were considered. To calculate the weights of the importance of the criteria, the hierarchy analysis method was used. By fuzzy criteria using the Fuzzy VICOR method, a comparative analysis of several franchises was conducted. As a result, the best franchise for doing business was revealed. The Fuzzy VICOR method allows to get an effective result even in the conditions of uncertainty of input data.

    Keywords: decision making, franchising, fuzzy decision making method, hierarchy analysis, defuzzification, Fuzzy VICOR

  • A method for assessing the security of a special purpose automated information system against DDoS attacks based on a theoretical-empirical approach

    A model that implements a method for assessing the security of a special purpose automated information system is considered in the article. The model takes into account both the intensity of the load on the system and the number of channels as a means of protecting information from DDoS attacks based on the combination of theoretical and empirical approaches to assessing security of special purpose automated information system. The transition from a theoretical model using empirical states and continuous time to a discrete time model is applied to build a new model. The purpose of the work is to develop a model that implements a method for assessing the security of a special purpose automated information system against DDoS attacks based on a theoretical-empirical approach to modeling information protection means against DDoS attacks.The following tasks are solved in the article: analysis of known models that implement the method for assessing the security of special purpose automated information system from DDoS attacks; the model which implements a method for assessing the security of special purpose automated information system based on a theoretical-empirical approach to modeling information protection against DDoS attacks is being developed. The use of the new model makes it possible to apply both empirical values obtained as a result of measurements or modeling, and a theoretical basis for modeling information protection means under the influence of DDoS attacks, taking into account their characteristics, which will be reflected by the income function and the choice of the optimal mode of functioning of the special purpose automated information system in discrete moments in time. When synthesizing the models presented in the article, the lack of the static nature of the assessment of the security of the special purpose automated information system was eliminated, the intensity of computer attacks such as DDoS, which dynamically changes both the parameters evaluating the means of protection and the probability of the system being in critical states, was taken into account.

    Keywords: automated system, modeling, security assessment, queuing system, probabilistic assessment, DDoS attack

  • Cognitive models of support and sustainability of professional dynasties

    It is necessary to study the mechanisms of supporting the sustainability and reproduction of professional dynasties in order to better understand the relationship between the constructive and destructive effects of professional dynasties on the development of professional spheres. The most convenient tools for this purpose can serve as a cognitive and simulation modeling. The purpose of this article is to build cognitive models that demonstrate the mechanisms of supporting the stability and maintaining the stability of professional dynasties. The main research method is cognitive modeling. The models are based on the idea of the dual potential of professional dynasties, which is expressed in a deeper and earlier primary professional adaptation and in the formation of a social monopoly. The article presents 4 cognitive models: model of professional self-preservation dynasties through the monopolization of the professional sphere, model resist external destruction of the system, model to reduce the level of prioritization and conflicts with the institutional environment, a general model of the sustainability and development of professional dynasties. Professional dynasties, due to the desire for leaktightness, develop mechanisms that are aimed at the development of dynasties. These mechanisms also serve to support conservation and enhance sustainability. Also, it is necessary to understand the succession strategies of children from professional dynasties by using simulation models. They are based on some factors that are involved in the transmission of the statuses and practices of professional dynasties and were considered in the cognitive models from the article.

    Keywords: professional dynasties, cognitive modeling, stability of professional dynasties, sustainable development of professional models

  • Vectorization and parallelization of the particle-particle method

    This paper considers the vectorization and parallelization of the "particle-particle" method used to take into account interactions between objects in the mathematical modeling of physical processes, using the example of taking into account the space charge when calculating the dynamics of charged particles. Comparison and estimation of time costs are carried out (as a test problem, the expansion of a multicomponent ion beam during one nanosecond with a step of Δt = 10-12 s was considered), taking into account the acceleration due to vectorization and parallelization between processor cores. It is concluded that the results of the work clearly demonstrate that the vectorization of computations can significantly speed up the computation time, and the explicit replacement of scalar operations with vector ones makes it possible to obtain additional speed-up in comparison with the use of automatic optimization of the program code. Key words: parallel computations, "particle-particle" method, vectorization of computations, numerical modeling, Coulomb interactions, dynamics of charged particles, ion beam, program code, equation of motion, mathematical model.

    Keywords: parallel computations, particle-particle method, vectorization of computations, numerical simulation, Coulomb interactions, dynamics of charged particles, ion beam, program code, equation of motion, mathematical model

  • Application of the energy method to the calculation of a two-phase body

    The stress-strain state of a two-phase body under the action of a load is described using a system of partial differential equations (Lame equations), the analytical solution of which can be obtained for a narrow class of problems. To apply one of the variational methods to solving the generalized Lamé system, a functional is written based on the potential energy of deformations, which allows us to expand the range of tasks for the study of mechanical processes in soil foundations under engineering structures.

    Keywords: two-phase body, water-saturated soil base, potential energy of a two-phase body, stress-strain state

  • Processing and assimilation of observation data obtained by satellite sensing for monitoring the current state of heterogeneous objects on the water surface

    The study is devoted to the analysis of satellite observations data assimilation to discover the necessary information for developing and verifying mathematical models of hydrodynamics and biological shallow-water kinetics. The use of satellite earth sensing data is taken to enhance information base. The possible use of neural networks with optical flow computation is considered in the study. The objective of the study is to develop a software tool used to identify the initial conditions in mathematical modeling of hydrobilogical shallow-water processes. The article illustrates the relevance of applying the observational data processing from satellite earth sensing. There are considered the necessity and possibility of using the neural network approach with the optical flow computation in solving problems of information processing from gray-scale snapshots.

    Keywords: mathematical modeling, shallow water body, satellite sensing data, neural network, contour, image processing

  • Development of a web service for searching files by keywords

    The subject of research is the development of a service for searching through user files for a given set of keywords with parameters. The available approaches to solving such a problem were studied and the most relevant one was selected. The service searches inside files with text content in order to automate the process of selecting the desired files among the entire set. Its work is based on Porter's algorithm and uses a text stemming approach in order to obtain more accurate results. Searches for the stem of a word, taking morphology into account. Performing a morphological parsing of a word, a base is found common for all its grammatical forms, cutting off suffixes and endings. As a result, the algorithm of the service allows you to search not just for the given keywords, but also takes into account their word forms, and also searches for several sets of keywords at once, each set is analyzed separately. In addition, you can specify ranges of numeric values ​​to search for. A feature of the service is that sets of keywords are searched together in nearby paragraphs within the range of -20 to +20 words from each other, thus taking into account the context of their appearance in the text. The service ranks the found documents according to the quality of their matching search criteria. Files in basic formats are processed: doc, xls, pdf, txt. The service operates on a Linux platform under the control of the Apache web server. Free software tools were used for development.

    Keywords: search engine, document analysis, stemming, Porter's algorithm, word forms, morphology, arithmetic mean of percent, web service

  • Thermal and humidity conditions object of historical and architectural heritage in St. Petersburg

    A study of the operation of the water heating system of the Naryshkin bastion of the Peter and Paul Fortress was carried out. The results of measurements of temperature and relative humidity of indoor air are presented. Based on the research results, a three-dimensional model of room No. 3 of the Naryshkin Bastion was built, which was used in numerical modeling using the STAR-CCM + hydrodynamic computer complex. Recommendations for improving the heat and humidity regime are given, prospects for further research of the object are identified.

    Keywords: object of historical and architectural heritage, microclimate parameters, water heating system, thermal regime, STAR-CCM +

  • Simulations of МТЗ-82 tractor transmission in Simulink

    The results of the study of the operation of the tractor transmission МТЗ-82 in various gears are given. Simulink simulations are used to automate research calculations.

    Keywords: transmission, tractor, simulation, Simulink

  • Modern methods and algorithms for solving fuzzy distribution (transport) problems, reflected in foreign literature

    The article discusses the work of foreign authors in the field of solving fuzzy distribution (transport) problems. To solve such problems in real conditions, it is rather difficult to formalize all parameters in the form of definite numbers, therefore, the field of solving fuzzy distribution (transport) problems attracts wide attention of scientists and experts, provoking numerous successful studies. To solve distribution (transport) problems, when considering the current state of foreign literature, the main approaches have been identified, consisting in the use of pentagonal, hexagonal, octagonal fuzzy numbers, ranking, intuitive fuzzy environment, as well as the Pythagorean approach. Now it is becoming more and more important to use inaccurate data in real transportation problems. The listed approaches to solving distribution (transport) problems give a certain effect in comparison with the existing ones, therefore it is necessary to investigate solutions of fuzzy distribution problems using modern approaches and methods.

    Keywords: fuzzy transport routing problem, optimization, fuzzy methods, fuzzy numbers, heuristic algorithms, hybrid algorithms

  • On Stabilization of Landslide Slope with TITAN Anchor

    The results of simulation of stabilization of landslide slope by method of finite elements are considered in the article. The slope stabilization system includes retaining reinforced concrete structures (newly erected and reconstructed) with an anchor support of the TITAN system.

    Keywords: landslide, landslide slope, landslide circus, retaining structures, anchor support, anchor, mathematical modeling, geomechanical modeling, finite element method

  • Optimizing maintenance intervals truck

    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

  • Bulk materials flow divider automation

    During the modernization of the cement plant and the transition to a new technology for the pro-duction of cement, the design of the divider for the flow of bulk materials was set as one of the tasks. In the future, with the successful implementation of the project, this would make it possible to use a common raw material warehouse that feeds two clinker kilns. The compiled mathematical model of the raw material flow divider made it possible to simulate transient processes in the op-eration of the mechanism. The created program and visualization of the process simplifies the work of the personnel operating the installation.

    Keywords: automation, operation, divider, modernization, cement industry

  • Calibtating tempered stable Levy models to quotes of cryptocurrencies

    In this article, we consider the problem of modeling the dynamics of cryptocurrencies using a wide class of tempered stable Levy processes. At the first step, the generalized Blumenthal-Getour index is estimated based on the realized power-law variation of a number of logarithmic returns of cryptocurrency rates. We consider the case when the jump activity index is less than one, which corresponds to Levy processes of bounded variation. The modeled process is then presented as a sequence of positive and negative Levy jumps over short periods of time. We calibrate the model to one-touch artificial digital options, which are the statistical probabilities of crossing predetermined barriers, and we suggest using the FFT in conjunction with the Wiener-Hopf method. The main advantage of our approach is the use of explicit Wiener-Hopf factorization formulas to determine the price of one-touch synthetic digital options within such models. The proposed technique simplifies the fitting of parameters of non-Gaussian Levy processes with jump activity not exceeding 1. In essence, we replace the original continuous-time process with a discrete process that approximates a tempered stable Levy process.

    Keywords: mathematical modeling, cryptocurrencies, Levy models, Tempered Stable Levy models, CGMY modes, Blumenthal-Getoor index, options

  • Synthesis of a vector control system for an electric vehicle motor with direct torque control

    The article demonstrates the problem of controlling an asynchronous motor of an electric vehicle in the acceleration mode and maintaining the speed of the vehicle at the desired value with dynamically changing torque. To solve the problem, the dynamics of the movement of an electric vehicle was described, a vector control system with direct torque control with switching the inverter keys was described, which provides a rapid change in the electromagnetic moment practically without changing the speed of rotation of the motor rotor. On the basis of the given model, the system was synthesized in the Matlab / Simulink package, and the simulation results were obtained. The synthesized control strategies ensure the achievement of the set task of accelerating and stabilizing the speed of an electric vehicle, taking into account the passport characteristics of an electric vehicle, and the stability of a closed system.

    Keywords: electric vehicle, control systems, vehicle dynamics, vector control, direct torque control

  • Development of a hardware and software bench for calculating the main parameters of a vortex-type wind power plant

    This article discusses a hardware and software complex for the study of aerodynamics and electromechanical characteristics of wind turbines (WPP) with a vertical axis of rotation. The created laboratory stand makes it possible to carry out experimental studies of the developed wind power plants, to obtain the dependences of the angular speed of rotation of the rotor and the consumed electric power on the wind speed. To demonstrate the efficiency of the considered vortex-type wind turbine, the corresponding prototypes of wind turbines with a power of 0.2 kW and 1.2 kW were designed and assembled, and their full-scale tests were carried out. The developed software makes it possible to carry out numerical simulation of the motion of a wind turbine with an unsteady undisturbed wind flow, taking into account the mass-inertial characteristics of the installation and the nature of the moment of resistance to the rotation of its rotor. Experimental and numerical results obtained using the developed hardware-software complex are presented and compared. These results indicate the possibility of using such a complex as an effective tool for the development of wind turbines with a vertical axis of rotation.

    Keywords: wind power plant, experimental research, software and hardware complex, numerical modeling, numerical methods of dynamics of continuous media

  • Re-engineering of the algorithm and software implementation of the discrete slicer prototype

    In this paper, we consider a modification of the algorithm and software implementation of the prototype of a discrete-rotary slicer for preparing 3D printing on multi-axis printers, which allows you to prepare printing for a larger number of types of product models compared to the original algorithm and software prototype. An approach is proposed that provides for the choice of one of several secant planes at certain steps of constructing a layer-by-layer model. The software prototype was refactored. The results of the prototype work are presented, showing the efficiency of the proposed approach. Original protoptype is more constrained with the model types it can process compared to proposed one. Though further investigation of the proposed approach have to be done as well as introduction of parallel implementation of different sectant planes processing.

    Keywords: diversification of management, production diversification, financial and economic purposes of a diversification, technological purposes of ensuring flexibility of production

  • Conceptual model of optimal management for ensuring water and energy security in the context of climate change

    The article discusses the characteristics of the glacial zone and the zone of formation of river flow in Tajikistan due to climate change. A special role in the context of climate change is assigned to the development of a conceptual model of optimal management to ensure water and energy security of the Republic of Tajikistan at the organizational level, technical and economic levels. The aim of creating a conceptual model is to manage large reservoirs with multi-year regulation for power generation and river flow, create conditions for the accumulation of water during high water periods and increase the water content of rivers during low water periods. The implementation in practice of the idea of a conceptual management model ensures optimal control of the water-energy system. The advantage of the model is the transition from the command-administrative method of management to the systemic method of management in the aisles of hydrographic, energy and consumer parameters.

    Keywords: atmospheric precipitation, river runoff, melting of glaciers, climatic conditions, reservoirs, hydropower resources, long-term regulation, management, conceptual model, optimization

  • Simulation of polymer corrosion in aggressive environments based on percolation theory

    This article discusses modeling of polymer corrosion in aggressive environments based on percolation theory. Within the framework of the work, an algorithm for modeling polymer corrosion was developed, and a program that implements this algorithm in C ++. Paper describes the corrosion modeling algorithm, the structure of the implemented program, and the simulation results for various parameters. The result of this work is an algorithm modeling and an application that performs modeling of the polymer corrosion process in aggressive environments based on the percolation theory according to the developed algorithm, as well as building an image of the damaged material, graphs of the dependence of the length of the boundary of the corrosion region and the area of the remaining material on the modeling step. Algorithm uses Monte-Carlo method for determing area of corrosing region and is suitable for parallel implementation.

    Keywords: percolation theory, corrosion modeling, simulation of physical processes, Monte Carlo method, visualization of simulation results

  • Mathematical modeling of the surface of deformation foci in the process of manufacturing profile pipes

    A mathematical model of the surface of deformation zones as a set of flat cross-section described on the basis of spline functions for profiling pipes in rollers with subsequent calibration is proposed.

    Keywords: Mathematical model, deformation zone surface, flat cross-section, spline functions, рipe profiling

  • Software for the control system for the technical condition of the main equipment of thermal power plants

    The problem of digitalization of the data accounting system and the problem of managing the technical condition of equipment at thermal power plants are considered. The performance of the entire thermal power plant depends on the operation of the boiler units. If the equipment fails and the necessary measures to resolve the emergency are not taken in time, then the probability of a decrease in the plant's performance up to the suspension of work increases. Thus, the issue of monitoring the technical condition of all operating equipment is relevant. The developed software for automation of the data recording system and visualization of technical parameters of the reliability of boiler and turbine equipment is described. The software has a methodology for determining the technical condition index of equipment. The software was developed using the JavaScript programming language, the React.js library. Digital technologies have been introduced into the process of recording data on the technical condition of equipment, where for the first time the software includes a method for automatic calculation of the technical condition index of boiler units. The software ensures that equipment downtime is reduced, as well as the likelihood of failure or critical breakdown of boilers. Thus, the operation of the software makes it possible to reduce the likelihood of an emergency state of the main equipment of power plants.

    Keywords: thermal power plant, boiler and turbine equipment, software, technical condition, reliability, repairn

  • Methodology for developing practical tasks for automated control of knowledge and skills in training IT specialists

    The article discusses the features of the proposed methodology for developing practical tasks for automated control of knowledge and skills in training IT specialists. The methodology is presented using the example of tasks for controlling knowledge and initial skills in the field of software testing and describing the functional requirements for software. The application of the methodology contributes to the development of e-learning tools and distance learning technologies in training IT specialists (in particular, university students in relevant areas). The research is supported by a stipend of the President of the Russian Federation to young scientists and post-graduate students (No. SP-100.2018.5), which was assigned by the grants Council of the President of the Russian Federation.

    Keywords: IT specialist, professional knowledge and skills, knowledge and skills control, automated training systems, software testing

  • Multichannel satellite image application for water surface objects identification

    The paper is devoted to the analysis of methods of adoption of satellite observation data in order to identify the required information used in the development and verification of mathematical models of hydrodynamics and biological kinetics of shallow water reservoirs. For the information accumulation, we consider the use of remote sensing data. The aim of the paper is to identify the best implementation method for software tools in order to improve the quality of assimilation of date of satellite sensing of the Earth relating to hydrobiological processes in a shallow water reservoir. The results of the work indicate the clarity and relevance of the use of high-tech methods for filtering ERS images. The modern methods of accentuation of contours of objects based on discontinuities in the brightness of a halftone image, used in real time or time close to it, have been considered, and their algorithms have been briefly described.

    Keywords: mathematical modeling, shallow water reservoir, satellite sensing data, filtering methods, Kirsch, Sobel, LoG, LBP, operator, recognition, contour

  • The researching of ways to increase the speed of encoding and decoding of Reed-Solomon codes

    The problem of increasing the coding and decoding speed of Reed-Solomon codes (RS-codes) is considered. The implementation of the Open JPEG encoding system library was chosen as a base implementation for comparison. This task is considered for an x86-64 environment. The paper proposes ways to improve performance both when using a standard set of instructions and when using vector instructions from the SSSE3 and AVX2 sets. A technique for comparing the speed of encoding / decoding RS-codes is described using the example of the developed library and the basic implementation in Open JPEG. An experimental study of the relationship between the parameters of RS-codes, the encoding / decoding rate, and the set of instructions used is carried out. It is shown that for any RS-code it is possible to significantly increase performance even on a standard set of instructions. A method is proposed for the dynamic selection of the encoding acceleration method depending on the instructions supported by the target computer and the parameters of the used RS-code.

    Keywords: anti-noize coding, Reed-Solomon codes, speed, vector instructions

  • Using a metamodel as a basis for describing spatial data

    The article deals with the representation of spatial data in the framework of a metamodel. The metamodel is supplemented with a subsystem for evaluating data quality. Descriptors for a particular set of spatial data are provided.

    Keywords: meta-model, quality of spatial data, set of descriptors evaluation, quality assessment