The step-by-step construction of a computer model of the process of long-angle drawing of profile pipes is considered. The minimum dimensions of the blanks have been determined, the use of which ensures the necessary dimensions of the finished product. The scheme of applying a deforming force with size adjustment in the current state during step-by-step deformation is taken into account. Geometric and finite element models have been obtained that make it possible to find all the parameters of the deformation site during the drawing process.
Keywords: dimensions of the workpiece, profile pipe, boundary conditions, load application, physical model, finite element grid
The paper considers the experience of using neural networks in construction. The widespread coverage of AI success in various areas of construction has led to an increase in business and public interest in the successful implementation of AI in various construction areas. Examples of the use of neural networks in the construction expertise of the working documentation "Metal structures" and "Metal detailed structures" are given. The process of solving the assigned tasks by an expert builder in comparison with the answers received by the neural network is described. A comparative analysis of the quality of the results obtained by the expert builder and artificial intelligence is given. As part of this study, the main algorithms for training neural networks that are applicable to solving the problem were analyzed. Particular attention is paid to algorithms capable of efficiently handling parameter variations and new configurations not represented in the training dataset. The use of these algorithms will provide increased accuracy when scaling the solution. A neural network forecast for this area of construction expertise is given.
Keywords: neural network, construction, construction expertise, expert builder, comparative analysis, training sample, neural network forecast
At the moment, quantum key distribution (QKD) technology guarantees the highest level of data exchange security, which makes QKD networks one of the most promising areas in the field of computer security. Unfortunately, the problem of topology optimization when planning and extending QKD networks has not attracted enough attention. This paper reviews approaches that use analytical models in the topology optimization problem of quantum key distribution networks. Different methods that solve problems of network capacity and security maximization and cost minimization are reviewed, the utilized algorithms are described, and conclusions about possible further research in this area are drawn.
Keywords: quantum key distribution, mathematical modeling, network topology, analytical modeling, topology optimization
The simulation model of Apache HTTP Server as a mass service system is considered, the parameters of the corresponding system and Apache HTTP Server are compared using GPSS World environment. The comparison of the simulation model with a real web server is based on the construction of a test server. using Apache JMeter application, which can be used to simulate high load on the server. Query generation and statistics collection was done by Apache JMeter application. A comparison of both reports was given, differences in characteristics were pointed out, and assumptions about the reasons for the differences were outlined. The model can be applied to establish requirements for Apache HTTP Server in order to optimise its performance.
Keywords: simulation modelling, mass service system, efficiency characteristics, test server, flow of requests, service channels, queue
The article analyzes the impact of transformation types on the learning quality of neural network classification models, and also suggests a new approach to expanding image sets using reinforcement learning.
Keywords: neural network model, training dataset, data set expansion, image transformation, recognition accuracy, reinforcement learning, image vector
This paper investigates the effectiveness of the distance fields method for building 3D graphics in comparison with the traditional polygonal approach. The main attention is paid to the use of analytical representation of models, which allows to determine the shortest distance to the objects of the scene and provides high speed even on weak hardware. Comparative analysis is made on the possibility of wide model detailing, applicability of different lighting sources, reflection mapping and model transformation. Conclusions are drawn about the promising potential of the distance field method for 3D graphics, especially in real-time rendering systems. It is also emphasized that further research and development in this area is relevant. Within the framework of this work, a universal software implementation of the distance fields method was realized.
Keywords: computer graphics, rendering, 3D graphics, ray marching, polygonal graphics, 3D graphics development, modeling, 3D models
The article describes the methodology for developing a client-server application intended for constructing a virtual museum. The creation of the server part of the application with the functions of processing and executing requests from the client part, as well as the creation of a database and interaction with it, is discussed in detail. The client part is developed using the Angular framework and the TypeScript language; the three-dimensional implementation is based on the three.js library, which is an add-on to WebGL technology. The server part is developed on the ASP.NET Core platform in C#. The database schema is based on a Code-First approach using Entity Framework Core. Microsoft SQL Server is used as the database management system.
Keywords: client-server application, virtual tour designer, virtual museum, three.js library, framework, Angular, ASP.NET Core, Entity Framework Core, Code-First, WebGL
The work is devoted to the analysis of machine learning methods for solving problems of automatic document processing. The study considers such methods as classification, information extraction, pattern recognition and natural language processing and their application in the analysis of text data. An analysis of existing algorithms and models, including linear models, decision trees, support vector methods, and a comparison of their effectiveness depending on various conditions and parameters is carried out. Particular attention is paid to the problems that specialists face when using machine learning methods in working with documents, such as data quality, the need for pre-processing and tuning of model parameters. Prospects for further research in this area and examples of possible integration of modern machine learning methods to improve the efficiency and accuracy of automatic document processing in various industries are given.
Keywords: machine learning, automatic document processing, computational experiment, artificial intelligence, classification models, software package
Flight safety is one of the most important priorities of civil aviation. In recent years, there has been a downward trend in the number of aviation accidents, which is associated with the introduction of new technologies and training methods. One of these methods is computer simulator training (CTP).KTP is a training method in which LE specialists practice skills and procedures in a virtual environment that simulates real flight conditions. KTP allows you to increase the effectiveness of training, reduce the risk of errors and ensure that training meets modern safety requirements aviation simulators, development of simulator systems, simulators of aviation instrumentation.
Keywords: aviation simulators, development of simulator systems, flight instrument equipment simulators
Models and a software package have been developed that allow for the analysis of counterparties for the probability of fulfilling government contracts. A comparative analysis of machine learning models has been conducted: logistic regression, decision forest, clustering, and neural network. A software package has been developed that allows for contract forecasting. A computational experiment has been conducted to analyze counterparties taking into account contracts that have been fulfilled or not completed by them. The best model has been established, demonstrating a forecast accuracy of 97.89% by the accuracy metric.
Keywords: mathematical modeling, cybersecurity, intelligent models, financial sector, government contracts, information infrastructure
Multilayer edge commutation in 3D integration technologies can simplify the design of microassemblies and reduce the length of edge electrical connections. However, this commutation is vulnerable to thermomechanical stresses and requires preliminary analysis of the product design. This paper shows the results of modeling various variants of multilayer edge commutation for 3D microassemblies, differing both in the dielectric material used at the edge redistribution layer and in the material for sealing the microassembly volume. It has been established that the lowest values of thermomechanical stresses in commutation are characteristic of materials whose temperature coefficient of linear expansion is as close as possible to this parameter of conductors. At the same time, the use of composite dielectrics in redistribution layers leads to a more significant decrease in stresses than the use of more thermally stable unfilled polymers.
Keywords: 3D integration, packaging, thermomechanical stresses, polyimide, redistribution layer
The article is devoted to the development of an algorithm for three-dimensional terrain reconstruction based on single satellite images. The algorithm is based on the algorithmic formation of three-dimensional models based on the output data of two deep learning models to solve the problems of elevation restoration and instance segmentation, respectively. The paper also presents methods for processing large satellite images with deep learning models. The algorithm proposed in the framework of the work makes it possible to significantly reduce the requirements for input data in the problem of three-dimensional reconstruction.
Keywords: three-dimensional reconstruction, deep learning, computer vision, elevation restoration, segmentation, depth determination, contour approximation
The influence of the diffraction divergence of an acoustic beam on the characteristics of a single-channel acousto-optic correlator (AOC) is considered. A mathematical model is being developed to optimize the divergence of the acoustic beam of a single-channel acousto-optic correlator. It is shown that it boils down to amplitude and phase modulation of the pulse response of the device, and the nature of the parasitic modulation turns out to be invariant to the type of the correlator reference signal. As a result of numerical calculations, dependences were obtained that allow us to quantify the effect of diffraction divergence on the operation of the ACS. Methods of compensation for parasitic modulation are proposed, which makes it possible to improve the functionality of acousto-optic correlators.
Keywords: diffraction divergence of an acoustic beam, mathematical model of an acousto-optic correlator, ultrasonic light modulator, electroacoustic transducer, reference transparency
The paper proposes a hybrid multi-agent solution search algorithm containing procedures that simulate the behavior of a bee colony, a swarm of agents and co-evolution methods, with a reconfigurable architecture. The developed hybrid algorithm is based on a hierarchical multi-population approach, which allows, using the diversity of a set of solutions, to expand the areas of search for solutions. Formulations of metaheuristics for a bee colony and a swarm of agents of a canonical species are presented. As a measure of the similarity of two solutions, affinity is used - a measure of equivalence, relatedness (similarity, closeness) of two solutions. The principle of operation and application of the directed mutation operator is revealed. A description of the modified chromosome swarm paradigm is given, which provides the ability to search for solutions with integer parameter values, in contrast to canonical methods. The time complexity of the algorithm is O(n2)-O(n3).
Keywords: swarm of agents, bee colony, co-evolution, search space, hybridization, reconfigurable architecture
The article offers a variant of the development of lighting design projects for outdoor architectural lighting. Based on the modeling of light distribution in the DIALux 4.13 program, brushes have been created using specific lighting devices that simulate lighting effects from real lighting devices. A variant of the sketch of outdoor architectural lighting using Adobe Photoshop has been created with the implementation of local lighting techniques using the example of a drama theater building. Using a three-dimensional model of the object, a light design project was created in the DIALux EVO program. The proposed method of creating sketches is useful in professional activities related to the development of sketches of lighting design projects based on their high-quality photographs without the need to develop three-dimensional models, for conceptual proposals of fragments of the urban light environment and landscape territories. Having developed a base of brushes (based on real light distributions of lighting devices), it is possible to create sketches of architectural lighting of buildings that implement various lighting techniques.
Keywords: adobe photoshop, dialux 4.13, dialux evo, sketch, brush, building facade, outdoor architectural lighting, lighting effect, lighting technique, architectural lighting concept
To check the efficiency and correctness of the implementation of primary and secondary signal processing algorithms in onboard radar systems for Arctic purposes in the functional tasks of detecting weather conditions that are potentially hazardous to flight, it is advisable to use numerical modeling of radar signal simulators. This is due to the fact that during preliminary tests under adverse weather conditions there is a potential danger of losing control over the flight of the radar carrier, especially in the case of developing unmanned aircraft platforms. In addition, there are very rare weather phenomena, such as wind shear, the detection of which during tests is an unlikely event. All this leads to the fact that the development and debugging of onboard radars for low-altitude carriers that solve the problem of meteorological navigation during flight, it is advisable to carry out the method of semi-naturalistic modeling, using databases for the formation of reflected signals that contain a set of initial parameters that allow imitation either in real time or according to a pre-planned flight scenario and a prepared special set of signal signature records. This article proposes an algorithm for working with a database and subsequent numerical modeling, which allows estimating the necessary spectral components of signal signatures for a pulse-Doppler radar that estimates the radial component of wind speed in each resolution element, which is used for further calculation of the F-factor of wind shear hazard.
Keywords: airborne radar, database, simulation, numerical modeling, meteorological navigation, Arctic, wind shear
In this paper, heat transfer in a staggered tube bundle under steady and pulsating flow conditions is analyzed using numerical simulation. The numerical study was conducted for tube bundles with 5, 10, and 15 longitudinal rows. The Reynolds number Re and the Prandtl number Pr were 3400 and 3 respectively. Flow pulsations were characterized by both symmetrical and asymmetrical reciprocating flow. The effect of pulsations was estimated using the product of the relative dimensionless pulsation amplitude and the Strouhal number A/DSh, which corresponded to values of 0.1, 0.25, and 0.4. The numerical study was conducted using Ansys Fluent. The flow hydrodynamics in the tube bundle was described using the Reynolds-averaged unsteady Navier-Stokes equations. Based on the results of numerical simulation, it was found that the effect of pulsations on heat transfer in the tube bundle varies depending on the number of longitudinal rows. It is shown that an increase in the number of rows leads to a decrease in the Nusselt number ratio in a pulsating flow compared to a steady flow. It is established that the thermal-hydraulic efficiency increases with an increase in the number of rows. It is shown that asymmetric pulsations are more effective than symmetric ones for intensifying heat transfer when taking into account energy costs
Keywords: heat transfer intensification, staggered tube bundle, heat transfer, numerical simulation, flow pulsations
The article is devoted to the consideration of multi-criteria Pareto optimization methods based on genetic algorithms. The NSGA-III and AGE-MOEA-II methods are considered, and their comparative analysis is given. The results obtained are important both for theoretical research in the field of genetic algorithms and for practical application in engineering and other fields where multicriteria optimization plays a key role.
Keywords: multicriteria optimization problem, Pareto front, genetic algorithm, NSGA-III, AGE-MOEA-II
Since 2017, EVRAZ ZSMK JSC has been developing and operating a mathematical model covering all processing stages from ore extraction to final products – SMM Forecast. The model will be used to calculate technical cases, plans, and parity prices for iron ore and coal, and its use brought more than 200 million rubles of economic effect in 2020 alone. The use of a universal mathematical model made it possible in 2023 to begin the development of a module for daily optimization of an agglomeration factory and blast furnace production. The article discusses the experience of EVRAZ ZSMK JSC in the development and implementation of a daily planning system based on the monthly planning model of SMM Forecast, as well as methods for achieving an acceptable speed of multi-period optimization. The SMM Forecast system was originally designed for end-to-end, scenario-based calculation of the main raw materials from ore and coal to finished products in a volumetric monthly planning. The system uses optimization algorithms to search for a global target function to maximize margin income under specified constraints. The mathematical model of redistribution uses the norms and technologies specified in the company's regulatory documents. At the same time, the model is universal and the transfer of algorithms from monthly to daily mode was carried out with minimal modifications. The article also discusses the difficulties encountered and various methods of solving these problems. The first problem faced by the developers was the low speed of optimization of the model in daily dynamics due to the strong complication of the optimization load. The calculation time has increased significantly, and to solve this problem, it took the introduction of a number of optimization cycles aimed at reducing the speed of solving equations, introducing variable boundaries, and determining starting points. As a result, the calculation time for one month was about 40 minutes. The second problem was the need to develop a complex supply management algorithm and optimize stacking at the sinter plant. As a result of solving this problem, a working tool has been developed that brings additional income to the enterprise.
Keywords: metallurgy, modeling, planning, daily planning, sintering plant, blast furnace shop, stacking
The purpose of this work is to study the applicability of the U-Net architecture for automatically determining the contours of natural skins using the TensorFlow and Keras libraries in Python. A software application has been developed based on methods including OpenCV libraries, as well as a model for implementing a deep convolutional neural network. The dataset for training and testing the network was created using augmentation. Training was carried out using the stochastic gradient descent method after splitting the data sample into training and test images. In the future, the results obtained will be used to create an automated system that will make it possible to determine the contours of the skin and its defects, which in turn will open up the possibility of calculating the useful area of the skin and creating an automated layout of patterns taking into account the identified defects.
Keywords: computer vision, edge detection, natural skin, machine learning, convolutional neural networks, U-Net architecture, deep learning
The rocks that form a natural geological reservoir for underground gas storage, during the operation of UGS, are exposed to prolonged cyclic loads caused by periodic injections and withdrawals of natural gas. At the same time, it is possible to develop and accumulate residual deformations in rocks that cause irreversible changes in the properties of rocks and this must be taken into account when designing and operating UGS.
Keywords: underground gas storage, geomechanical modeling, cavern, salt massif, deformations
the work is devoted to a comparative analysis of various calculation and mathematical models among themselves. The calculation of the frame joint of reinforced concrete structures is performed: a pylon and a cantilever beam. Three methods for performing the calculation of this joint are proposed: an analytical method, a rod FEM model and a volumetric FEM model. The analysis of the calculation results is performed: a comparison of internal forces and calculated reinforcement. The consequences of a superficial analysis of the structure and simplification of calculation models are shown using the example of damage to a real structure under the action of operational loads.
Keywords: reinforced concrete console, structure calculation, node calculation, Lira 10, Russian software, optimal design of reinforced concrete structures, reinforcement analysis
A mathematical model for managing a commercial organization that specializes in the production and sale of asphalt and asphalt concrete is presented and analyzed in this paper. The study is based on mathematical modeling principles and management theory. An organized two-tier management system has been proposed, consisting of an asphalt manufacturer and its clients. The problem was considered numerically using various types of input data, and the company "FIRM PROFILE LLC" provided necessary information for calculations. The paper analyzes the results obtained and offers practical recommendations for improving the management of this enterprise.
Keywords: optimal management, mathematical modeling, simulation modeling, enterprise model, hierarchical system
This paper discusses the influence of the turbulence model selection in predicting heat transfer in tube bundles in two- and three-dimensional settings. Numerical studies were performed for in-line and staggered tube bundles using Ansys Fluent software with three RANS turbulence models (k-ω SST, RSM EWT, and RNG k-ε) and a laminar solver. The tube lengths l in three dimensions were 0.5D and 3D, with a fixed tube diameter D. The Reynolds number Re ranged from 100 to 2900. The results showed that the turbulence model selection affects the qualitative flow pattern in tube bundles, with two-dimensional structures predominating in the flow regardless of the turbulence model selection. Therefore, the tube length has virtually no effect on the ability to predict heat transfer intensity. It is shown that when using the laminar solver, the effect of the bundle tube length can be significant depending on Re and the bundle layout. Good agreement with experimental data is obtained for the RSM EWT and RNG k-ε EWT models. For a staggered bundle, when choosing the k-ω SST model, satisfactory agreement with experimental data is observed, while the heat transfer of the in-line bundle is significantly underestimated. The use of the laminar solver in a steady-state formulation is justified for a pronounced laminar flow, at Re < 1000 with a further increase in Re, it is necessary to use a unsteady formulation with sufficient time and mesh resolution.
Keywords: convective heat transfer, in-line tube bundle, staggered tube bundle, computational simulation, turbulence modeling
The article deals with multi-criteria mathematical programming problems aimed at optimizing food production. One of the models of one-parameter programming is associated with solving the problem of combining crop production, animal husbandry and product processing. It is proposed to use the time factor as the main parameter, since some production and economic characteristics can be described by significant trends. The second multi-criteria parametric programming model makes it possible to optimize the production of agricultural products and harvesting of wild plants. in relation to the municipality, which is important for territories with developed agriculture and high potential of food forest resources.
Keywords: parametric programming, agricultural production, two-criteria model