Mathematical models and computer simulation experiment
Reference:
Avtushenko A.A., Ripetskii A.V., Avtushenko A.A.
Modeling and testing of a thermal board adapted to additive technologies for manufacturing using computational methods
// Software systems and computational methods.
2019. № 4.
P. 1-19.
DOI: 10.7256/2454-0714.2019.4.30631 URL: https://en.nbpublish.com/library_read_article.php?id=30631
Abstract:
The authors consider a geometric model of a thermal board based on actual data obtained using the methodology of adaptation to additive manufacturing technologies of heat exchangers. The question of solving the problem of finding the most effective thermal card option by the computational method among the selected options is investigated and a comparison is made with the experimental sample made by the additive technology method to verify the selected method for obtaining computational data. The authors analyze 62 selected options for thermal boards, with the adaptation of the computational grid in the thermal board matrix. For testing, a special installation was assembled and samples were made on an EOS M290 printer. The main research methods used in the work: computational and comparative-analytical methods to obtain data on the selected options and determine the effective sample, as well as experimental to verify the data.The novelty of the study lies in the development of an effective geometric form of the thermal board and the manufacture of the selected sample by the method of additive technologies. The selected geometric model of the thermal board is manufactured using the additive technology method at the lowest cost, the rods and bases of the thermal board are self-supporting elements that do not need support. The results of research tests of a prototype thermal board confirm the correctness of the selected calculation method for determining the effective design of a thermal board manufactured by the additive technology method.
Keywords:
type of heat exchanger, geometry optimization, supports, computational grid, computational method, additive manufacturing, finned rods, radioelectronic equipment, thermodynamic characteristic, test type of heat exchanger
Automation of manufacturing and production planning
Reference:
Amosov A.G.
Algorithm for constructing the geometry of movement of special vehicles
// Software systems and computational methods.
2019. № 4.
P. 20-29.
DOI: 10.7256/2454-0714.2019.4.30842 URL: https://en.nbpublish.com/library_read_article.php?id=30842
Abstract:
The current problem of the lack of an algorithm for constructing the movement of special vehicles is considered in the paper. The aim of the research is to develop a software package for calculating the rotation of a multi-link special vehicle, taking into account an algorithm that describes the characteristic features of the movement of special vehicles.An increase in the dimensions and mass of long cargoes necessitates the creation of new designs of special vehicles, the distinguishing feature of which is multi-linkage and long-wheelbase, which in turn reduces maneuverability and requires taking into account the peculiarities of movement along a curve.To study the process of moving special vehicles, a geometric modeling method was used to develop an analytical geometric model for the rotation of the tractor and semitrailer. Based on geometric modeling, a method for determining the turning characteristics of a multi-link vehicle has been developed. It has been shown that patency of special vehicles is no less important in comparison with durability, the law of changing the ratio of steering angles of the steered wheels, different axles should provide the maximum turning moment at the maximum steering angles of the front steered wheels, and should also ensure equality of wear at small angles.
Keywords:
special vehicles, path of motion, geometrical adjectives, software package, automation, curvilinear motion simulation, algorithm, rotation angle, flow chart, process
Telecommunication systems and computer networks
Reference:
Kokoreva E.V., Kostyukovich A.E., Doshchinsky I.V.
Estimation of measurement error of a user's location in Wi-Fi network
// Software systems and computational methods.
2019. № 4.
P. 30-38.
DOI: 10.7256/2454-0714.2019.4.31316 URL: https://en.nbpublish.com/library_read_article.php?id=31316
Abstract:
The article presents the results of the analysis of the error in calculating the coordinates of a mobile subscriber using three Wi-Fi access points, based on measuring the received signal power. The purpose of the study was to develop a geographic system for large storage facilities and a preliminary assessment of the accuracy of calculations in conditions close to real ones. The principles of local and global positioning based on the measurement of various physical characteristics of signal propagation were considered, a method was selected for the implementation of a positioning system. The authors developed a test bench layout of a map on the IEEE 802.11 standard mobile network and software for solving this problem using the trilateration mechanism. To simulate the surrounding electromagnetic environment, a parameter imitating additive white Gaussian noise was added to the calculation formulas. In the course of the work, graphical dependences of the error of measuring the coordinates of the object on the signal / noise ratio in the channel and on the distance from the reference access point are obtained. The results showed that even in the worst operating conditions, the developed system surpasses most systems on the market in terms of measurement accuracy.
Keywords:
location, RSSI, distance, trilateration, geopositioning, access point, Wi-Fi, coordinates, power, accuracy
Mathematical models and computer simulation experiment
Reference:
Zinoviev A.N.
The technology for observing the effect of thermo-gravitational anomaly by the equipment of the space radio telescope of the RadioAstron project on the orbital resonance interval.
// Software systems and computational methods.
2019. № 4.
P. 39-54.
DOI: 10.7256/2454-0714.2019.4.31209 URL: https://en.nbpublish.com/library_read_article.php?id=31209
Abstract:
The object of study is the Spektr-R spacecraft with a space radio telescope on board. As sensors, the equipment of two onboard hydrogen frequency standards is used. Long-term monitoring of telemetric and scientific information transmitted from the spacecraft, suggested the presence of external physical influences on the equipment of the space radio telescope. The evolving elliptical orbit of the Spektr-R spacecraft allowed us to scan the region of the orbital resonance of the spacecraft with the Moon and estimate the magnitude of the physical effect on the onboard hydrogen frequency standard. As a method of measuring the range of the Spectrum-R spacecraft, the reverberation-correlation method was used, which allows synchronous range measurements to be made during radio astronomy observations. The presented technology confirmed the assumption of the gravitational nature of the physical impact on the elements of the space radio telescope. A new method for detecting orbital resonance on board a spacecraft has been obtained. Changing the pressure of molecular hydrogen under conditions of orbital resonance significantly reduced the synchronization error of the onboard and ground quantum time scales.
Keywords:
molecular detector, space radio telescope, ion pump, gravitational wave, molecular hydrogen pressure, highly informative radio channel, hydrogen frequency standard, time dilation, spacecraft, quantum time scale
Automation of manufacturing and production planning
Reference:
Pavlov P.Y., Sosnin P.I.
Case-oriented geometric modeling of aircraft parts and components
// Software systems and computational methods.
2019. № 4.
P. 55-65.
DOI: 10.7256/2454-0714.2019.4.30735 URL: https://en.nbpublish.com/library_read_article.php?id=30735
Abstract:
When designing complex and multi-item products, the problem of positioning parts relative to each other and matching various coordinate systems at the stages of the life cycle appears. The article deals with the design and technological preparation for the production of pipeline systems of aircraft using welding. The production preparation process is focused on reusable geometric modeling of parts and their assemblies, which remain connected with the master geometry of the corresponding aircraft. For the integration of models, a specialized ontology is used. The proposed tools provide the necessary accuracy in the positioning of parts in conditions oriented to the use of a welding robot for preliminary welding. The article discusses the use of a case-oriented approach and the extension of the existing precedent model by skeletal geometric models using the example of parts and piping systems of aircraft systems. The main feature of the proposed means of skeletal geometric representation of parts and piping systems of aircraft systems is their coordinate relationship with the master geometry as a single ontological source information. The proposed models can be used as an extension of the attribute part of the design documentation, which is then used to prepare the production of assembly of pipeline units by welding.
Keywords:
design and technological preparation of production, welding, precedent model, ontology, master geometry, part, assembly unit, aircraft pipeline, aircraft, coordinate system
Knowledge Base, Intelligent Systems, Expert Systems, Decision Support Systems
Reference:
Shilnikov A., Mitsel A.
Remuneration Decision Support System "Oplata truda"
// Software systems and computational methods.
2019. № 4.
P. 66-76.
DOI: 10.7256/2454-0714.2019.4.31178 URL: https://en.nbpublish.com/library_read_article.php?id=31178
Abstract:
The subject of the research paper is the question of wages at the enterprises of Russia, as well as an object considered the remuneration system and the problem of their choice. In this regard the authors offer a model of a decision support system that will allow users to obtain the likely results of the introduction of a particular wage system in the enterprise, without actual testing. The principle of the model of this system is based on simulation modeling, which allows you to obtain and evaluate statistics using regression analysis and make an adequate managerial decision. In the framework of the article, the fundamental method is simulation. Using it, it is possible to build an adequate model and reflect options for the results of the enterprise. The article reveals in a new way the issue of choosing wage systems and combines economic and mathematical approaches;For the first time, the algorithms of simulation modeling are described in the question of the choice of wage systems in enterprises;A model of a decision support system in the field of remuneration is obtained, which is scientifically justified and easy to understand, as a result of information processing in which the user receives data on the consequences of introducing one or another standard remuneration system at his enterprise;A feature of the model is its scalability. In the sense that other salary systems can be added to, appraised in the general system model, in addition to pre-laid.
Keywords:
piecework system, time system, Monte Carlo method, algorithms, wage systems, simulation modeling, decision support system, time bonus, modeling, data base
Simulation systems
Reference:
Akhmedova S.M.
Research of a flexible production system by methods of imitating modeling at a stage of sistemotechnichal design
// Software systems and computational methods.
2019. № 4.
P. 77-86.
DOI: 10.7256/2454-0714.2019.4.31350 URL: https://en.nbpublish.com/library_read_article.php?id=31350
Abstract:
Object evaluation - assessment of the feasibility of designing a new object at the initial stage - computer experiments using simulation methods and presenting simulation results on a monitor using animation methods in two or three-dimensional spaces. In the article devoted to the tasks of creating simulation models, various RAO-studio software systems are used, which are designed for the development and development of simulation models in the language of RDO. Taking into account the requirements, RAO-Studio is studying a specific GPS object; cutting rolled metal sheets on sheets and sheets on cards, cleaning their surface. RAO-studio allows you to play a dynamic object on a computer, make decisions using a control system, and solve the problems of system analysis and synthesis of objects. Taking into account the requirements of RAO-studio for working with the GPS object as an example, cutting rolled metal sheets on sheets and sheets on frames, cleaning their surface leads to the following issues: development of a conceptual model of the site adopted as the object of study; development of structural-kinematic diagrams of GPS; development of the architecture of a computer-aided modeling tool of a GPS simulation model in the RDO language using RAO-studio bookmarks; development of a simulation algorithm for GPS; development of GPS control algorithm on the Internet. development of a GPS control algorithm in existing production using the results of a simulation model and a control algorithm in a video broadcast of a Petri net.
Keywords:
algorithm, modeling, knowledge base, production system, industrial robot, flexible production module, simulation model, conceptual model, data Base, animation
Systems analysis , search, analysis and information filtering
Reference:
Ignatenko A.M., Makarova I.L., Kopyrin A.S.
Methods for preparing data for the analysis of poorly structured time series
// Software systems and computational methods.
2019. № 4.
P. 87-94.
DOI: 10.7256/2454-0714.2019.4.31797 URL: https://en.nbpublish.com/library_read_article.php?id=31797
Abstract:
The aim of the study is to prepare for the analysis of poorly structured source data, their analysis, the study of the influence of data "pollution" on the results of regression analysis. The task of structuring data, preparing them for a qualitative analysis is a unique task for each specific set of source data and cannot be solved using a general algorithm, it will always have its own characteristics. The problems that may cause difficulties when working (analysis, processing, search) with poorly structured data are considered. Examples of poorly structured data and structured data that are used in the preparation of data for analysis are given. These algorithms for preparing weakly structured data for analysis are considered and described. The cleaning and analysis procedures on the data set were carried out. Four regression models were constructed and compared. As a result, the following conclusions were formulated: Exclusion from the analysis of various kinds of suspicious observations can drastically reduce the size of the population and lead to an unreasonable decrease in variation. At the same time, such an approach would be completely unacceptable if, as a result, important objects of observation are excluded from the analysis and the integrity of the population is violated. The quality of the constructed model may deteriorate in the presence of abnormal values, but may also improve due to them.
Keywords:
statistics, big data, linear model, anomaly detection, regression analysis, data cleaning, semi-structured data, modelling, noise removal, econometrics
Mathematical models and computer simulation experiment
Reference:
Pekunov V.V.
Refined calculation of droplet distributions in modeling atmospheric multiphase media
// Software systems and computational methods.
2019. № 4.
P. 95-104.
DOI: 10.7256/2454-0714.2019.4.30707 URL: https://en.nbpublish.com/library_read_article.php?id=30707
Abstract:
In this article the author considers the problem of increasing the accuracy of the search for adequate droplet distributions in the numerical simulation of multiphase media including the droplet phase. This problem is especially relevant when calculating the distributions with discontinuities that occur during intercellular droplet transfer, which have their own speed, as well as in the presence of sharp drops droplets, for example, of a technogenic nature. Tasks of this kind are often encountered in calculating the processes of formation and spread of pollutants in the air, in particular when modeling acid rain. The problem of constructing distributions is considered using the methods of computational mathematics (theory of interpolation), taking into account the physical laws of conservation of mass and number of drops. The elements of the method of moments (Hill method) and the sectional approach to modeling the droplet phase are used. A new approach is proposed for modeling droplet distributions by piecewise spline interpolation according to the density and concentration of droplet components, also relying on the constructed preliminary piecewise linear distributions. The results were compared with data obtained by direct modeling of many drops, as well as data obtained using exclusively piecewise linear distributions. The higher accuracy of the proposed approach is demonstrated in comparison with the original method using only piecewise linear distributions and a rather high calculation speed is shown in comparison with the Lagrangian approach.
Keywords:
multi-component flows, pollutant absorption, evaporation, condensation, multi-phase media, splines, interpolation, droplet distribution, method of moments, calculation speedup
Computer graphics, image processing and pattern recognition
Reference:
Shekhovtsov G.A., Zhilina N.D., Raskatkina O.V.
Non-contact method for determining the linearity of crane rails of bridge cranes by processing photo images
// Software systems and computational methods.
2019. № 4.
P. 105-114.
DOI: 10.7256/2454-0714.2019.4.31110 URL: https://en.nbpublish.com/library_read_article.php?id=31110
Abstract:
The article describes a method for determining the linearity of crane rails of bridge cranes by processing photo images. The method does not require marking of the shooting points on the rails, the use of special devices and performing a large number of angular, linear or other measurements. The method uses a horizontal reference line drawn on the image or created using the image on the image of the thread hanging freely in front of the lens cord plummet. The line can also be created using the Plumb-bob program, which gives the image of a vertical line. The image processing algorithm is described using a raster image editor to determine the deviations of the axial points of the rail from the reference line. Various options are being considered for determining the size of one pixel depending on the shooting distance and the height of the camera above the rail. The results of measurements and their comparison with the results obtained by traditional methods, which showed a difference of 0-5 mm are presented. An algorithm for determining the number of pixels contained in a line corresponding to a given distance to any shooting point is described, which allows for the determination of deviations in the image anywhere in the crane path.
Keywords:
non-contact measurements, straightdness, reference line, plumb, basis, pixel, photo images, camera, crane rail, deviation
Computer graphics, image processing and pattern recognition
Reference:
Pritykin F.N., Nebritov V.I.
Determination of the shape and size of the area in six-dimensional space defining permissible instantaneous states of the mechanism of the arm of an anthropomorphic robot
// Software systems and computational methods.
2019. № 4.
P. 115-124.
DOI: 10.7256/2454-0714.2019.4.31065 URL: https://en.nbpublish.com/library_read_article.php?id=31065
Abstract:
With automated planning of the movement of the arm mechanism of an anthropomorphic robot in organized space, there is a need to reduce the time it takes to calculate the trajectory in the space of generalized coordinates. The indicated time significantly depends on the calculation time of the vector of increments of the generalized coordinates at each calculation step in the synthesis of motions along the velocity vector. In the article the geometric studies based on the study of the size and shape of a region in a multidimensional space of generalized speeds specifying the permissible instantaneous states of the arm mechanism of an anthropomorphic robot are carried out. Based on this study a method is proposed that allows one to reduce the time of iterative search of the vector of increments of generalized coordinates. To establish analytical dependences reflecting the relationship between the geometric parameters of the specified area and the generalized coordinates of the arm mechanism, which determine the positions of the configurations, hypersurfaces in four-dimensional space are used. For this, the equations of interpolating polynomials located in four mutually perpendicular planes are used. Based on these four interpolating polynomials, a fourth-order hypersurface equation is obtained that reflects the relationship of geometric and kinematic parameters. The article also presents the results of virtual modeling of the movement of the arm mechanism of an anthropomorphic robot, taking into account the position of the forbidden zone in the system ACAD. The results of calculations using the obtained analytical dependences showed a reduction in the calculation time of test tasks. The conducted studies can be used in the development of intelligent motion control systems of autonomously functioning anthropomorphic robots in an organized environment without the participation of a human operator.
Keywords:
kinematic model, geometric modeling, space of generalized coordinates, movement synthesis of manipulator, objects of multidimensional space, humanoid robot, instant states of mechanism, velocity vector, nodal points of mechanism, linear shifts
Computer graphics, image processing and pattern recognition
Reference:
Gradov O.V., Aleksandrov P.L., Gradova M.A.
Study of mineral samples relevant for desert locations using software correlation spectral analysis of scanning electron microscopy registers: from 2D Fourier spectra to online analysis of statistics of integral spatial characteristics
// Software systems and computational methods.
2019. № 4.
P. 125-171.
DOI: 10.7256/2454-0714.2019.4.31379 URL: https://en.nbpublish.com/library_read_article.php?id=31379
Abstract:
The purpose of this article is to demonstrate the possibility of identifying minerals characteristic of desert regions under expeditionary conditions and in small laboratories that do not have the means to provide energy dispersive microanalysis (EDXMA) or mapping methods of wave dispersive spectroscopy (WDXRS), due to the use of hotel points as an identification technique and areas of interest (ROI) on a sample of correlation spectral image analysis (QAVIS) software. It is proved that this technique allows the identification of individual, resource-valuable minerals using the integral frequency and integral spatial characteristics, as well as the Fourier spectrum itself and the correlogram between the samples. Registration was made on the JEOL JSM system digitized by P.L. Alexandrov (IBCh RAS). The measurements were carried out using QAVIS software, developed at the Far Eastern Branch of the Russian Academy of Sciences by the team of the Laboratory for the Analysis of Oceanological Information (developers - Goncharova A.A., Fischenko V.K.), Department of Information Technology, Pacific Oceanological Institute named after V.I.Ilicheva FEB RAS. Efficiency of video processing is provided by using one of the “fastest” discrete Fourier transform libraries - FFTW and careful optimization of the QAVIS program code by the authors of this program (the program works with computer video memory, which allows you to process all frames of the video stream at the same time as it is viewed on a computer screen). Thus, it has been shown that program correlation-spectral analysis can serve in working with desert and relevant minerals not only for additive analysis of minerals using scanning microscopy methods, but also for distinguishing submicrostructures of these formations and obtaining histograms of statistical distributions of their descriptors.
Keywords:
FFTW library, mineral shape computation, real time mode, Fortran, C general-purpose programming language, Discrete Fourier Transform, correlation spectral analysis, two-dimensional Fourier transform, image analysis, surface roughness