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  • Numerical analysis of connections of steel structure elements

    The practical significance associated with the development of automated software systems for calculating joints of steel structures of buildings and structures is noted. Using the IDEA Statica software package as an example, the calculation and analysis of the operation of a steel unit connecting the lower chord of a truss to a column was carried out. The order and sequence of entering the initial data for calculating the connection is shown. The calculation results present in tabular and graphical forms the equivalent stresses and plastic deformations of the main elements, as well as the results of inspections of bolted and welded connections of these elements to each other. A comparative analysis of numerical and analytical calculations was performed. Conclusions are formulated based on the results presented in the article.

    Keywords: calculation model, connections, steel structures, component finite element method, design, nonlinear analysis, work analysis, stress, plastic deformation, bolted connection, welded connection

  • Visualization of scientific data using interpolation methods and the NVIDIA IndeX plugin in the ParaView software

    The paper presents a solution to the problem of accelerating the process of visualizing the results of numerical simulation. The volumes of such data can be very large and the development of tools to speed up the process of analyzing modeling results is an urgent task. This article proposes a solution to the problem based on the development of a set of programs that automate the process of processing large-volume scientific data of the same type to create high-quality visualizations of the results of numerical modeling. The results are presented using the example of solving problems in astrophysics, but the proposed methodology can be quite easily applied to other subject areas in which models based on the dynamics of particle systems are used. The research described in the work is devoted to solving issues related to converting data obtained from numerical modeling into a format that can be read by the ParaView softwart, which implements many methods that allow obtaining very high-quality visualization. The work also describes the process of automating batch processing of a large amount of data that has the same structure, presents the results of an analysis of the acceleration of the visualization process when using the NVIDIA IndeX plug-in, and considers the possibility of improving the quality of visualization results when applying Delaunay triangulation to the original data.

    Keywords: data visualization, Delaunay triangulation, rendering acceleration, ParaView, NVIDIA IndeX, VTK

  • Localization of round objects in images using fast radial symmetry transform

    Currently, there is an increase in the number of scientific papers on models, methods and software and hardware for image processing and analysis. This is due to the widespread introduction of computer vision technologies into information processing and control systems. At the same time, approaches that provide fast image processing in real time using limited computing resources are relevant. Such approaches are usually based on low-level image filtering algorithms. One of the tasks to be solved in computer vision-based systems is the localization of round objects. These objects have the property of radial symmetry. Therefore, the approach based on the Fast Radial Symmetry Transform, which is considered in this paper, is effective for solving this problem. The paper describes the basic steps of the basic transformation, provides a procedure for determining the centers of radially symmetric areas for localization of round objects in images, and discusses examples of its application.

    Keywords: computer vision, image processing, image analysis, localization of objects, methods of localization of round objects, fast radial symmetry transf, detecion of the centers of radially symmetric areas

  • Low-Latency Wavelet Image Processing Using the Winograd Method with Convolution Step

    Wavelets are widely used in various fields of science and technology for processing 1D signals and multidimensional images. However, technical information processing devices are developing more slowly than the amount of digital data is growing. Computational latency is the most important characteristic of such devices. This paper proposes an implementation of the Winograd method with a convolution step 2 to reduce the latency of wavelet image processing. The proposed scheme for implementing calculations has reduced the asymptotic computational complexity of wavelet processing of 2D images to 53% compared to the direct implemettaion method. A theoretical assessment of the computing device characteristics showed a reduction in latency of up to 67%. A promising direction for further research is the hardware implementation of the proposed approach on modern microelectronic devices.

    Keywords: image processing, Winograd method, digital filtering, computational delay, wavelet transform, convolution with step

  • Artificial intelligence and decision theory: current trends

    The activities of modern enterprises and organizations are becoming increasingly complex, which complicates decision-making tasks. In this regard, the issues related to the integration of innovative information technologies in the field of decision-making are being updated. One of these technologies is artificial intelligence, the main advantages of which are the ability to solve time-consuming tasks and perform analysis based on big data in real time. The purpose of the work is to analyze the methods of applying artificial intelligence technologies in the theory of decision-making. The paper considers the fundamental factors associated with the work of artificial intelligence, prospects and current trends in its development in solving decision-making problems. The scientific value of the article consists in an attempt to systematize knowledge regarding the use of intelligent technologies in decision-making theory. The materials of the article can be useful for modern software developers and the management of organizations.

    Keywords: artificial intelligence, algorithm, data analysis, decision-making, model, information technology

  • Using statistical edge-based modeling for motion detection in video

    In this article we present a novel algorithm for detecting moving objects using a stationary camera, which is based on statistical background modeling using edge segments. Traditional algorithms that rely on pixel intensity struggle in dynamic environments due to their inability to handle sudden changes in lighting conditions. These algorithms also tend to produce ghosting artifacts when a sudden change occurs in the scene. To address this issue, edge-based features that are robust to intensity variations and noise have been introduced. However, existing methods that rely on individual edge pixels suffer from scattered edge pixels and cannot effectively utilize shape information. Additionally, traditional segment-based methods struggle with variations in edge shape and may miss moving edges that are close to the background edges. In contrast to conventional approaches, our proposed method constructs the background model using regular training frames that may include moving objects. Furthermore, it avoids the generation of ghosting artifacts. Additionally, our method employs an automatic adaptive threshold for each background edge distribution to facilitate matching. This enhances the robustness of our approach to changes in illumination, camera movement, and background motion. Experimental results demonstrate that our method outperforms other techniques and efficiently detects moving edges despite the aforementioned challenges.

    Keywords: motion detection, edges, canny edge detector, gaussian of color, gaussian of gradient magnitude, normal distribution, adaptive thresholds, statistical map

  • The regression modieling the level of Ia river, Irkutsk State

    Analyses for the current publishes show that the problem of forecast water overflowing is actual and often causing a lot health threaten and other dangerouses. This article offers computing, analysis and development the regression model of the level of Ia river. The final model correspont the real data with proper level. The final calculation means that this model could be used for real forecast for defend the people from water's overflow.

    Keywords: model, simulation, river, water level, flood, emergency, forecast, statistics, monitoring, analysis, iya river, Irkutsk region

  • Algorithm for fragmentation and defragmentation of formal contexts

    A combinatorial problem - the problem of finding the set of all formal concepts of formal concepts is considered. The computational complexity of the problem is that the number of formal concepts depends exponentially on the size of the initial formal context. in the article to solve this problem, an algorithm for fragmentation and defragmentation of the formal context is given, based on the method of decomposing the formal context into fragments. The essence of the method is that the original formal context is divided into various fragments. The fragments have different sizes and a non-empty intersection. Each fragment is subsequently considered as a formal context and can again be subject to decomposition. As a result, a finite set of fragments is formed. Then formal concepts are found in each fragment and combined to form the desired set of all formal concepts of the formal context. The method is “non-distorting”: when dividing the context into fragments, new formal concepts are not formed and the sought-for concepts are not lost. The results of computational experiments are presented, showing the effectiveness of the developed algorithm.

    Keywords: formal concepts analisys, fragmentation algorithm, formal context, object-attribute table, combinatorial problem, the problem of finding the set of all formal concepts

  • Study of synchronization of almost-proportional and almost-periodic characteristics of time series

    In this study, an analysis of the time series was conducted using a class of shift functions for arithmetic and geometric progressions, along with their synchronization using logarithmic decrement. The closing prices of IBM company stocks were taken as the examined data for each trading day. The shift functions of geometric and arithmetic progressions revealed almost-proportions and almost-periods in the examined data. These detected patterns emphasize the importance of applying shift functions in the analysis of time series, allowing the extraction of internal patterns and periodic fluctuations that might go unnoticed with standard analysis methods. Computing the minima and corresponding values of the geometric progression enabled the identification of almost-periods in the data. These results not only confirmed visual observations but also enhanced our understanding of the internal patterns of the time series. The findings underscore the effectiveness of applying methods for analyzing time series based on almost-proportions and metric techniques. These approaches play a crucial role in uncovering hidden patterns and subtle periodicities in data, providing a fundamental foundation for more accurate analysis and successful forecasting.

    Keywords: nearly-proportionalities, synchronization of geometric progression, empirical data, geometric progression, shift functions

  • Investigation of geometric parameters in the approximation of curved surfaces

    The article considers the issue of studying the deviation of geometric parameters of a curved surface and a facet surface approximating it. The approximating surface was constructed by triangulation. To obtain adequate results when approximating a surface, it is necessary that the geometric parameters of the approximated surface differ minimally from the parameters of the faceted surface. One of the most important geometric parameters of a surface is its normal at a given point. The deviation of the normals of the given and approximating surfaces significantly affects the calculation error.

    Keywords: curved surface, faceted surface, normal to the surface, linear frame, tinted image, plane compartment

  • Automation of structural calculations of wooden light-framed buildings

    In connection with the revival of interest in wooden housing construction in Russia, the creation of specialized software systems for the calculation and design of buildings and structures made of wood is becoming relevant. One of the most popular systems in the world is light-frame housing construction. As one of the possible tools for automated design of light-frame wooden buildings, this article presents the FrameCAD program, developed at the Department of Metal, Wood and Plastic Structures of the Don State Technical University. Some of its capabilities are presented, allowing you to design wall fences of light-frame buildings, beamed wooden floors, perform calculations of individual frame elements taking into account the requirements of current regulatory documents and automatically generate albums of drawings of wooden structures in the domestic NormCAD program, as well as specifications for them factory made. FrameCAD has been tested in the design of a number of objects. The software product is developed by engineers who have many years of experience in the actual design and construction of light-frame buildings. It continues to be improved and supplemented, and in the future it may become a replacement for similar foreign complexes.

    Keywords: wooden structures, software package, wall panels, beam overlap, automated calculation

  • The mathematical modeling of heat transfer and hydrodynamics in plate-fin radiators with round fillets profile

    A numerical simulation was used to investigate heat transfer in plate-fin radiators with round fillet profiles of various depths, including 0.55 mm, 1.1 mm, and 1.5 mm. The issue of flowing air around a radiator with a mass flow rate of 10-3 to 4·10-3 кг/с and a temperature of 293 K was solved. The radiator was heated using a heater, whose temperature was set from 323 to 353 K. Changes in heat flow, pressure drop, and energy efficiency indicator were shown depending on the air mass flow, according to the calculation results. The research findings indicate that the radiator featuring round fillet profiles and a depth of 1.65 mm exhibits the highest heat flow and energy efficiency indicators, as well as the lowest pressure drop.

    Keywords: radiator, cooling system, numerical modeling, computational fluid dynamics, heat transfer, heat flow, pressure drop, energy efficiency, calculation, electronics

  • Obtaining an equivalent resistance modulus for a section of river with parallel arms

    The analysis of N.N. Pavlovsky's method for calculating the parameters of the riverbed in the branches is given. The reasons for the limitation of this method have been established. The Lagrange transform is used to find the extremum of the objective function for equations of uneven fluid motion, which makes obtaining an equivalent resistance modulus highly visual and easy to use. The results of the experiment are presented.

    Keywords: calculation method, multi-node sections of rivers, resistance modulus, N.N.Pavlovsky method

  • Calculation of sediment formation in a porous heat exchanger and assessment of the influence of sediment on heat flow

    Using numerical simulation, particle deposition in a porous heat exchanger was studied; the mechanism of sediment formation was sinvestigated, and the influence of sediment on the heat flow was assessed. The influence of porous heat exchanger length, dust particle size, and air flow velocity on particle deposition efficiency, particle breakthrough, and heat flux value was studied. Research results have shown that with increasing length of the heat exchanger, the efficiency of dust particle deposition increases, which leads to the formation of sediment. In turn, the sediment reduces the value of the heat flow from the porous heat exchanger. Depending on the length of the heat exchanger and air velocity, the reduction in heat flow is 3.43-7.27%.

    Keywords: porous media, heat exchanger, particle deposition, deposition efficiency, particle breakthrough, sediment, heat flow, numerical modeling, computational fluid dynamics, calculation

  • Design of a stand for testing the seismic resistance of butterfly check valves

    Tests to determine the seismic stability of elements of pipeline systems, in particular pipeline fittings, are included in the list of those necessary to confirm the operability of the element. In this study, a stand was developed for testing to determine the seismic stability of butterfly check valves, which are a type of pipeline fittings. A finite element analysis was carried out, data on maximum deformations, stresses and displacements of structural elements were obtained, and the response of the installation table to seismic impact was calculated. The resulting displacement values of the table structure do not exceed the limit values specified by the technical requirements and do not lead to distortion of the structure or destruction of joints, which makes it possible to move from design to manufacturing and commissioning of the stand.

    Keywords: vibration tests, seismic resistance test bench, pipeline, pipeline valves, swing back gate, mathematical modeling, finite element method, strength calculation, simulation modeling, stress-strain state

  • On the dynamics of a circular membrane with an elliptical hole

    The effectiveness of the modified Fourier method associated with the use of orthogonal splines is shown when solving the problem of dynamics of a circular membrane with an elliptical hole. A posteriori estimates of the accuracy of the obtained approximate solutions complement the previously proven theoretical convergence of the algorithm and characterize the high accuracy of solutions to the problem of membrane dynamics with a curved boundary. The differences between the approximate solutions of the problem presented in the form of finite series decrease with an increase in the number of grid nodes used in calculations.

    Keywords: Fourier method, orthogonal splines, finite series, dynamics of membrane, a posteriori estimation

  • Solving Poisson's equation using a physics-informed natural gradient descent neural network with Dirichlet distribution

    In this paper, a physics-informed neural network containing natural gradient descent is proposed to solve the boundary value problem of the Poisson equation. Machine learning methods used in solving partial differential equations are an alternative to the finite element method. Traditional numerical methods for solving differential equations are not capable of solving arbitrary problems of mathematical physics with equivalent efficiency, unlike machine learning methods. The loss function of the neural network is responsible for the accuracy of solving initial and boundary value problems of partial differential equations. The more efficiently the loss function is minimized, the more accurate the resulting solution is. The most traditional optimization algorithm is adaptive moment estimation, which is still used in deep learning today. However, this approach does not guarantee achieving a global minimum of the loss function. We propose to use natural gradient descent with the Dirichlet distribution which increase the accuracy of solving the Poisson equation.

    Keywords: natural gradient descent, Poisson equation, Fisher matrix, finite element method, neural networks

  • Mathematical modelling of the stress-strain state of the southern part of the Siberian craton

    The aim of this study is mathematical modelling of the southern part of the Siberian craton using the finite element method. The task of the study is to carry out mathematical modelling of the stress-strain state of the visco-elastic-plastic medium of the Yakutsk-Vilyui large eruptive province on the basis of the boundary value problem. Hypothesis of the study: the possibility of using the results of numerical study to determine the zones of mineral dislocations. In the southern part of the craton, on the territory of the Republic of Sakha-Yakutia, there are the richest oil and gas fields, the largest of which is the Ust-Vilyuyskoye field located in the southern part of the craton. Research method: numerical experiment carried out by the method of mathematical modelling. Results achieved: finite element studies were carried out, the possibility of using numerical methods was determined, the stress-strain state of the plate was analysed, and the locations of anomalies of dislocations of craton rocks were determined to identify potential oil and gas bearing fields.

    Keywords: craton, mathematical modeling, stress-strain state, geophysics, geotectonics, stretching, igneous province, material models, Hardening Soil model, finite element method, mineral dislocation

  • Application of the Hartmann formula for calibration of prism spectral devices in a wide range

    Prism spectral devices have a spectrum-variable dispersion and therefore a nonlinear relationship between the wavelength and the position of spectral lines on the focal surface of a spectral monochromator device, which makes it difficult to calibrate such devices in terms of wavelengths and dispersion.Most often, the well-known Hartmat formula is used for graduation. However, the accuracy of its calculation is satisfactory only in a limited spectral range, and therefore the calculation is carried out on overlapping areas no wider than 200 nm with averaging in overlapping zones. Averaging gives a calibration curve (and, accordingly, a dispersion curve) with gaps at the joints. In this paper, we consider the possibility of using a single calibration for the entire spectrum region, providing smooth, continuous calibration curves. The best result is obtained by using the Hartmann formula for the entire spectral range, after which a set of deviations of the calibration points is determined. This set is interpolated by a polynomial of an arbitrarily chosen order n using the least squares method.

    Keywords: monochromator, spectrum, calibration, dispersion, Hartmann formula, interpolation, polynomial

  • Application of ANI-2x force field for modeling polyphenylene sulfide using classic molecular dynamics

    This work examines the applicability of a specific force field model – ANI-2x – to the polymer polyphenylene sulfide. The order of the actions taken is given and, as a result, the radial distribution function of sulfur atoms in systems with different temperatures is compared. It was shown that qualitatively the ANI-2x field correctly describes the situation during the transition through the glass transition temperature.

    Keywords: poluphenylene sulfide, classic molecular dynamics, machine learning, force field, potential, polymer, computer simulation, model

  • Using segment tree in PostgreSQL

    The article considers an approach to solving the problem of optimizing the speed of aggregating queries to a continuous range of rows of a PostgreSQL database table. A program module based on PostgreSQL Extensions is created, which provides construction of a segment tree for a table and queries to it. Increased query speed by more than 80 times for a table of 100 million records compared to existing solutions.

    Keywords: PostgreSQL, segment tree, query, aggregation, optimization, PosgreSQL Extensions, asymptotics, index, build, get, insert

  • Preprocessing speech data to train a neural network

    This article analyzes data processing problems for training a neural network. The first stage of model training - feature extraction - is discussed in detail. The article discusses the method of mel-frequency cepstral coefficients. The spectrum of the voice signal was plotted. By multiplying the vectors of the signal spectrum and the window function, we found the signal energy that falls into each of the analysis windows. Next, we calculated the mel-frequency cepstral coefficients. The use of a chalk scale helps in audio analysis tasks and is used in training neural networks when working with speech. The use of mel-cepstral coefficients significantly improved the quality of recognition due to the fact that it made it possible to see the most informative coefficients. These coefficients have already been used as input to the neural network. The method with mel-frequency cepstral coefficients made it possible to reduce the input data for training, increase productivity, and improve recognition clarity.

    Keywords: machine learning, data preprocessing, audio analysis, mel-cepstral coefficients, feature extraction, voice signal spectrum, Fourier transform, Hann window, discrete cosine transform, short Fourier transform

  • Estimation of regression models with multiary modulus operation using least absolute deviations

    This article examines the previously studied linear in factors and non-linear in parameters modular regression model containing unary module operations. Through the use of binary, ternary, ..., l-ary module operations, a generalization of modular regression was proposed for the first time. A special case of generalization is considered - regression with a multiary operation modulus. The problem of accurately estimating such a model using least absolute deviations is reduced to a mixed integer 0-1 linear programming problem. Using data on farm productivity built into the Gretl econometric package, classical linear regression and modular regression with a multivariate operation were built. The quality of approximation of the proposed modular regression turned out to be higher than the quality of the linear model.

    Keywords: regression analysis, modular regression, least absolute deviations, multiary operation modulus, mixed integer 0-1 linear programming problem

  • Mathematical modeling of heat transfer and hydrodynamics in models of ceramic honeycomb heat exchangers

    Using numerical modeling, we performed studies of the influence of the angle of inclination of the plates of the regenerative heat exchanger element on the heating time and pressure drop. The studies were conducted for models of heat exchange elements with lengths of 6 and 20 mm. Depending on the length of the element, the angle of inclination of the plates was: 10°, 20°, 30°, 40° (at L=6 mm) and 3°, 6°, 9°, 12° (at L=20 mm). At the boundary of the calculation area, the air flow velocity and temperature were established, namely 1 and 3 m/s, and 303 and 973 K. The research results demonstrated that increasing the angle of inclination of the plates helped reduce the heating time of the regenerator by 38.56-49.1%, depending on the length of the heat exchange element, the speed and temperature of the air flow.

    Keywords: heat recovery, honeycomb heat exchanger, numerical modeling, calculation, heating time, pressure drop, heat exchanger geometry, angle of plate, air flow velocity, air flow temperature

  • Using an Intel UHD graphics on the math calculations

    Based on recent developments in the field of parallel computing, in particular at the SYCL abstraction level, the use of optimal parallel computing tools for building applications in the field of computational and applied mathematics is being considered. Examples are given of both simple computational algorithms and computations using mathematical libraries for computational linear algebra.

    Keywords: parallel code,heterogeneous enviroment, intel data parallel c++, intel oneapi, sycl, onemkl, fpga accelerator, gpu accelerator