×

You are using an outdated browser Internet Explorer. It does not support some functions of the site.

Recommend that you install one of the following browsers: Firefox, Opera or Chrome.

Contacts:

+7 961 270-60-01
ivdon3@bk.ru

  • Pulse control of electromagnetic drives

    The article proposes a variant of an electromagnetic drive for controlling an unmanned aerial vehicle for monitoring power facilities and develops calculation ratios that determine its electromechanical and dynamic processes. The structure and main characteristics of the pulse drive control have been developed. The conducted research can be used in the implementation of the steering drive project of a modern unmanned aerial vehicle.

    Keywords: electromagnetic drive, pulse control, multipolar pulse width modulation, block diagram, magnetic induction, moment, constant, pulse element, control current, inertia

  • Radiation cooling - current state and development prospects

    Radiative cooling is an innovative and highly promising passive cooling technology that allows surfaces to dissipate heat via infrared radiation directly into the cold outer space. Unlike traditional cooling methods that require an external energy source, radiative cooling operates autonomously, offering a sustainable and energy-efficient alternative for temperature control. This natural process has attracted considerable attention in recent years due to its potential to mitigate the growing energy demands associated with air conditioning and refrigeration, which contribute significantly to global energy consumption and environmental degradation.

    Keywords: radiation cooling, temperature, atmospheric window, air conditioning, energy efficiency, passive cooling, calcium carbonate, barium sulfide, boron nitride, titanium dioxide

  • Deformability of the soft shell of sawtooth-type fabric structures

    Framed fabric roof structures of the sawtooth-type are considered. The structures are arranged on rectangular plan. They consist of a number of sectors which are separated by arch-shaped supporting ribs. The sectors are covered with a prestressed soft shell. Geometric nonlinear static analysis of the shell is performed taking into account the effect of snow and wind loads. The general dimensions of the shell and the prestress value are considered as the primary variables. Quantitative assessment of deformation of the shell is carried out by means of so-called deformability index. The index is reciprocal to the relative deflection. A functional expression for approximating the deformability index is proposed. The expression is to be used at the stage of developing the design solutions for fabric structures. The coefficients of the function are found by means of the least squares method. The guidance for assigning the main parameters of the sawtooth-type fabric structures are given.

    Keywords: fabric structure, roof structure, soft shell, sawtooth roof, geometric parameters, prestress, deformability, approximation

  • Grain boundary mechanism of fatigue crack growth

    Overhead power line wires are affected by various external factors such as wind, ice deposits, variable temperature conditions, excessive humidity. This eventually leads to fatigue failure of the wire. It consists in the origin and slow growth of a fatigue crack. The final stage of destruction is the sudden movement of the crack at high speed. The paper proposes a model of slow crack growth, at the mouth of which there is a grain boundary. Under the influence of external stress, a section of the border is a source of vacancies. The resulting vacancy concentration gradient between the grain boundary and the free surface at the crack mouth leads to a diffusion flow of vacancies into the crack. From the solution of the diffusion problem, the magnitude of the flow and the rate of increase in the crack length are found.

    Keywords: crack, grain boundary, vacancy diffusion, fatigue failure, air line, mechanical stress, vacancy flow

  • Study of the effect of octyl phenol formaldehyde resin on the dynamic mechanical properties of vibration-absorbing materials based on butyl rubber

    Vulcanization is a technological process that transforms plastic rubber into rubber. As a result of vulcanization, the shape of the product is fixed, and the material becomes more durable, hard and elastic. The purpose of the article is to determine the effect of octyl phenol-formaldehyde resin on the vulcanization parameters and to identify its optimal amount for the development of vibration-absorbing materials based on butyl rubber. The effect of a vulcanizing agent (octyl phenol formaldehyde resin) on the properties of the rubber compound during vulcanization was established. As a result of the study, the kinetics of vulcanization and the effect of various components on the properties of the rubber compound, such as elongation at break, conditional tensile strength and specific damping ability, were studied. This study is conducted in order to find the optimal rubber for placement in a seismic damper used in buildings and structures.

    Keywords: vulcanizing group, vibration absorbing material, butyl rubber, rubber compound, vulcanization, octyl phenol formaldehyde resin, seismic damper

  • Image noise reduction using discrete cosine transform

    This paper considers the problem of removing noise from an image based on the discrete cosine transform (DCT) algorithm. Despite its simplicity, the algorithm is still popular in image conversion. However, recently there has been a strong development of convolutional neural networks, leaving behind “traditional” signal processing methods. In this paper, we study image denoising using DCT and convolutional neural networks and creating an interpretable convolutional neural network to obtain accurate data. The basis was the Python programming language and the library for working with neural networks – PyTorch. Based on this, a neural network model was trained on The Berkeley Segmentation Dataset. Experiments have shown that the trained neural network shows results comparable to traditional image denoising algorithms.

    Keywords: noise reduction, convolutional neural network, discrete cosine transform, machine learning, signal processing, Canny operator

  • The methodology of full-scale testing of reinforced concrete beams as part of a ribbed monolithic floor

    In accordance with the requirements of Federal Law No. 384-FZ, the safety and reliability of buildings and structures must be ensured. One of the ways to confirm the safety and reliability of building structures is to conduct field tests. The authors of this article have developed a method for full-scale testing of a reinforced concrete beam with a span of 14.52 m as part of a monolithic reinforced concrete ribbed floor. The procedure for testing the beam was drawn up with the development of measures to ensure safety during work, the adjustment of the beam testing method by loading was performed, the beam was tested by loading method with fixation of its deflections, followed by analysis of the test results. The test results showed that the developed method can be used as a full-scale test to confirm the safety and reliability of building structures, namely horizontal reinforced concrete structures.

    Keywords: building structures, beam, destruction, safety, methodology, technical condition, field tests

  • Algorithm for modeling the characteristics of crop production under unfavorable conditions

    The paper presents an algorithm for modeling production and economic characteristics for obtaining crop products, with the help of which planning problems are solved using multi-level parametric programming methods under average and unfavorable operating conditions for commodity producers. Since time series of characteristics associated with the production of products can be described by trends to assess adverse events, an algorithm for their identification was used based on the construction of multi-level trends according to the idea of ​​​​the hierarchical structure of the time series. When using this algorithm, a sequence of local minima is formed from the original series, a trend is built, and levels located below this trend, called unfavorable events, are identified. The assessment of the probabilities of these events is determined by the distribution law, which describes a number of differences in actual data and trend values ​​of a sequence of local minima. In the absence of trends and considering series of characteristics in the form of random variables, statistical and physical criteria are applicable to identify unfavorable events. As such, it is proposed to use the average value of local minima. Of the adverse events received, the smallest of them are distinguished, which represent rare events. Based on the identified events and other characteristics, the problem of optimizing the production of agricultural products is formed, the solution of which allows us to obtain optimal production volumes in accordance with maximum incomes corresponding to the calculated probability of events. A comparative analysis of planning results under average conditions and taking into account unfavorable events shows the likely losses of commodity producers at the enterprise and municipal district level.

    Keywords: parametric programming, trend, adverse event, production and economic characteristics, crop production, losses, risks

  • Efficiency of heat separation in various configurations of the leontiev pipe

    The article presents a numerical simulation of energy separation (thermal stratification) in a Leontiev tube, conducted using STAR-CCM+ software. The study focuses on a comparative analysis of two different tube designs, each intended to create temperature differences in gas flows. The simulation revealed that the supersonic flow passing through the tube significantly increases in temperature at the outlet, while the subsonic flow, on the contrary, shows a noticeable decrease in temperature. Detailed profiles of gas velocity and temperature are provided for both designs, demonstrating the effectiveness of each Leontiev tube variant in creating distinct areas of gas with different temperatures without the need for additional external heat exchange. The results obtained are of practical significance for improving the efficiency of gas distribution stations, enabling more effective management of thermal flows and preventing the formation of gas hydrates, as well as for use in other technological processes where temperature separation in flows is required without external heating or cooling.

    Keywords: Leontiev tube, numerical simulation, STAR-CCM+, thermal stratification, gas flow

  • Contact zone shear test results using breaking load

    The article deals with the peculiarities of the results of tests carried out to determine the characteristics of the contact zone organized by stamping on a steel plate. During the test, the specimen was in the steel mold in which it was manufactured. The steel form was used to prohibit horizontal movement of the steel thin plates and minimize the effect of uneven slippage of the steel gouge in the direction perpendicular to the shear force. The considered tests were carried out according to a specially developed methodology, which took into account the specifics of the contact zone shear operation, the applied tooling and took into account the set objectives of the study.

    Keywords: contact zone, contact characteristics, test methodology, shear tests, stamping, composite design

  • Method for ensuring data confidentiality using orthogonal matrices

    The application of orthogonal matrices in information processing and transformation systems is considered. A method is proposed for assessing the results of protective masking of audio information using Walsh-structured quasi-orthogonal Mersenne matrices.

    Keywords: orthogonal matrix, message masking, masking/unmasking algorithm, amplitude-frequency response, white noise, root mean square error, signal-to-noise ratio

  • Construction of horizontal protective screens from pipes during the construction of tunnel-type structures

    The article discusses the method of constructing a horizontal protective screen made of large-diameter steel pipes used for the construction of tunnel-type structures using a closed method. The factors influencing the choice of this method are analyzed - features of the construction site, economic and time indicators. As an example, a project for constructing a protective screen made of large-diameter pipes for the construction of a two-section transport tunnel under railway tracks is considered. Diagrams are provided that provide basic information about the construction project, its main parameters are considered: geometric shape and dimensions, location of structural elements with an indication of their sizes. The sequence of construction work is presented, consisting of six main stages, starting with the construction of auxiliary working pits and ending with the construction of the internal structures of the tunnel. Such construction of tunnels in dense urban areas requires taking into account and minimizing their impact on existing structures and transport routes in the construction area. The article presents the results of numerical calculations of stabilized movements of the soil mass, confirming the effectiveness of this method.

    Keywords: horizontal protective screens, tunnel-type structures, large-diameter pipes, soil deformations

  • A way to increase the bearing capacity of columns during the reconstruction of buildings

    The article presents a way to increase the load-bearing capacity of a reinforced concrete column due to metal clips from the corners with an increase in the load on it. To ensure the joint operation of the existing column and the metal cage, the corners are subjected to prestressing, which is achieved by compressing the corners with jacks.

    Keywords: reinforced concrete column, column reinforcement, metal cage, prestressing of the cage

  • Differences and prospects for the development of cloud, fog and edge computing technologies

    The article thoroughly explores cloud, fog, and edge computing, highlighting the distinctive features of each technology. Cloud computing provides flexibility and reliability with remote access capabilities, but encounters delays and high costs. Fog computing focuses on data processing at a low level of infrastructure, ensuring high speed and minimal delays. Edge computing shifts computations to the data source itself, eliminating delays and enhancing security. Applications of these technologies in various fields are analyzed, and their future development is predicted in the rapidly evolving world of information systems.

    Keywords: cloud computing, fog computing, edge computing, cloud technologies, data processing infrastructure, scope of application, hybrid computing, Internet of Things, artificial intelligence, information systems development

  • Development of an algorithm for recognizing human emotions using a convolutional neural network using Python tools

    This article deals with the problem of analyzing and recognizing human emotions using sound data processing. In view of the increase in the scope of application, which is largely caused by the difficult epidemiological situation in the world, the solution of the described problem is an urgent issue. The main stages are described: the audio data stream is recorded and, in accordance with the “sound fingerprinting” approach, is converted into an image that is a spectrogram of the sound data set. The stages of training a convolutional neural network on a pre-prepared set of sound data are described, and the structure of the algorithm is also described. To validate the neural network, a different set of audio data was selected, not participating in the training. As a result, graphs were constructed demonstrating the accuracy of the proposed method.

    Keywords: neural network; human emotion recognition; convolutional neural network; sound fingerprinting; Tenserflow; Keras; Matlab; Deep Network Toolbox