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  • 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

  • Investigation of the properties of metals during impact indentation using neural network analysis

    Indentation is a universal and practical method for obtaining material characteristics, especially when it is impossible or difficult to expose the material to other measuring methods. Experimental data on the mechanical properties of various types of materials were obtained using the shock loading unit. A mathematical model based on the finite element method was used to verify the experimental results. The article considers the solution of the problem of classification of neural metals with different mechanical properties. As part of the work, an artificial neural network has been created that allows the distribution of materials into selected groups. It is determined that a significant advantage of using neural networks is the ability to process experimental data and identify complex nonlinear dependencies, which makes them in demand in tasks related to the study of material properties.

    Keywords: impact indentation, neural network, task of classification, artificial intelligence, dynamic indentation, non-destructive testing.

  • Optimal cutting of rolled metal in the context of two-dimensional design of bar structures

    Bar structures are widespread in construction due to their economy, freedom of design shapes and sizes. As a result, automation of design and calculation of such structures is an urgent task. As part of the study, the task of developing a software module that generates a map of optimal cutting of rolled metal based on the results of calculations of rod structures has been implemented. The algorithm under consideration takes into account such features of the cutting optimization problem as taking into account the width of the blade, the possibility of using half the size of the rolled product, support for optimization of several sections, and welding of parts in case the length of the workpiece is exceeded. The software module is developed using JavaScript and C# languages. The ability to automatically generate cutting maps based on the results of optimization of rod structures increases the efficiency of designing building structures.

    Keywords: Design in construction, bar structure, computing system, web development, design in construction, rod structure, computer system, web development, optimal cutting, rolled metal, cutting map

  • Analysis of standard models of titanium oxide-based memristors for use in artificial intelligence systems

    The article discusses standard models of titanium dioxide-based memristors. A memristor is similar to a memory resistor and demonstrates a nonlinear resistance characteristic in which the charge parameter is a state variable. They can be used to create new types of electronic devices with high energy efficiency and performance, as well as to create machines that can learn and adapt to changing environmental conditions and in many practical applications: data storage memory (binary and multilevel), switches in logical electronic circuits, plastic components in neuromorphic artificial systems intelligence based on nanoelectronic components. It has been shown that when voltage is applied to charged ions, they begin to drift, and the boundary between the two regions shifts. When a sinusoidal alternating voltage of a given frequency is applied to the memristor, the shape of the volt-ampere characteristic (VAC) resembles a Lissajous diagram centered at the origin.

    Keywords: memristor, model, voltage characteristic, nonlinearity

  • Comparative analysis of the effectiveness of software tools for splitting videos into frames using the example of the field of road surface quality assessment

    Roads occupy an important place in the life of almost every person. The quality of the coating is the most significant characteristic of the roadway. To evaluate it, there are many systems, among which there are those that analyze the road surface using video information streams. In turn, the video is divided into frames, and the images are used to directly assess the road quality. Splitting video into frames in such systems works based on special software tools. To understand how effective a particular software is, a detailed analysis is needed. In this article, OpenCV, MoviePy and FFMpeg are selected as software tools for analysis. The research material is a two-minute video of the road surface with a frame rate 29.97 frames/s and mp4 format. The average time to get one frame from a video is used as an efficiency indicator. For each of the three software tools, 5 different experiments were conducted in which the frame size in pixels was consistently increased by 2 times: 40000, 80000, 160000, 320000, 640000. Each program has a linear dependence of O(n) average frame retrieving time on resolution, however, FFMpeg has the lowest absolute time indicators, as well as the lowest growth rate of the function, therefore it is the most effective tool compared to the others (OpenCV, MoviePy).

    Keywords: comparison, analysis, effectiveness, software tool, library, program, video splitting, frame size, resolution, road surface

  • Overview of energy storage interconnection topologies and its control methods

    Currently one of the promising trends in the global energy sector is the introduction of renewable energy sources (RES) into the existing grid. The use of RES can be favourable in autonomous power systems where fuel costs are high. However the stochastic nature of power generation creates a number of difficulties in maintaining the power balance. To solve this problem, it is proposed to connect a hybrid energy storage system (HESS) consisting of a battery and a supercapacitor to the load busbars. The efficiency of such HESS depends mainly on the way of its connection to the grid and the choice of control method. The article gives an overview of the existing mechanisms for controlling the power consumption of HESS.

    Keywords: Renewable energy, hybrid electricity storage, power converter topology, electricity storage control strategy

  • Automatic text summarization: overview of algorithms and approaches to quality assessment

    The paper presents an overview of the task of automatic text summarization. The formulation of the problem of automatic text summarization is carried out. The classification of algorithms for automatic text summarization by the type of the resulting summary and by the approach to solving the problem is carried out. Some existing problems in the field of automatic text summarization and disadvantages of certain classes of algorithms are described. The concepts of quality and information completeness of the summary are defined. The most popular approaches to the assessment of the information completeness of the summary and their classification in accordance with the methodology used are considered. The metrics of the ROUGE family are considered in relation to the task of automatic text summarization. Special attention is paid to the evaluation of the information completeness of the summary using such metrics of information proximity as the Kulback-Leibler divergence, the Jensen-Shannon divergence and the cosine distance (similarity). The metrics mentioned above can be applied to the text vector representations of the initial text and summary. The text vector representation in question can be performed using such methods like frequency vectorization, TF-IDF, static vectorizers and so on.

    Keywords: automatic summarization, summary, information completeness, ROUGE, vectorization, TF-IDF, static vectorizer, Kullback-Leibler divergence, Jensen-Shannon divergence, cosine distance

  • Reinforcement with composite materials to protect the reinforced concrete slab–column from pushing through the node

    Reinforced concrete flat slabs continue to be one of the most popular floor systems due to the speed of construction and their inherent flexibility in the layout of the premises. However, flat, non-rigid floors are subject to brittle fracture at the junction of the slab and column, which can spread and lead to the progressive collapse of a larger segment of the structural system. The lack of shear strength in two directions may be due to design errors, insufficient strength of the material, or overload.

    Keywords: reinforced concrete slab, punching, transverse reinforcement, fiberglass, carbon fiber

  • Disassembly mechanical cleaning of plate heat exchangers

    The article considers the problem of sediment formation, sludge and corrosion on the heat transfer surface during the operation of heat exchange equipment at housing and communal services facilities. A new method of non-selective mechanical cleaning using a water hammer is proposed. The description and principle of operation of this cleaning system at the central heating station of the Ogarev Moscow State University are given. To confirm the effectiveness of the proposed technical solution, the results of thermal and hydraulic tests are presented.

    Keywords: deposits, sludge, corrosion, cleaning, heat exchanger, water hammer, heat transfer

  • Prospects for the implementation of lean construction principles

    The construction industry is undergoing regular changes these days, influenced by many different factors. Large and structurally complex construction projects reveal more and more imperfections in traditional construction methods, e.g. increased time or production costs, downtime, delays, etc. Lean construction and its principles have emerged in search of solutions to problems in construction. In the search for solutions to problems in construction, the term - lean construction and its principles appeared, which replaced traditional methods and aimed at finding new approaches in the implementation of construction activities. In this scientific article the definition of Lean Construction is given, and also the history of Lean Construction and its chronology are considered. The comparison of the traditional construction model and Lean model is given, and also the connection of Building Information Modeling (BIM) with Lean Construction principles is analysed and an example of this connection is given.

    Keywords: lean manufacturing, lean construction, construction, lean construction principles, lean technology, lean model, lean philosophy, life cycle of an object, information modelling technologies, engineering

  • 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

  • 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

  • Framed steel earthquake-resistant structures traditional design principles

    The main means of seismic protection for increasing the seismic resistance of buildings and structures are described. The main problems associated with the design of special seismic protection equipment are outlined. The basic requirements for the design and calculations of steel frame frames taking into account seismic impact in accordance with the current design standards in the Russian Federation are analyzed. There is an insufficient description of the requirements specified in the standards for performing calculations and design of structures and their connections. Recommendations and instructions are given for taking into account the requirements of the standards for the design of steel frame frames. Schematic diagrams of special units for coupling columns with crossbars, necessary for design in seismically hazardous areas, are presented. Conclusions are formulated.

    Keywords: special units, columns, beams, seismic impact, seismic protection, steel frames, plastic hinges, excess strength factor, forces, plastic moment, design.

  • Application of three-phase foams to reduce the concentration of diesel fuel in water

    The effect of organomodified silica particles on the extraction of dissolved diesel fuel from water was studied. The dependence of the efficiency of water purification on the concentration and type of solid particles, as well as the concentration and type of surfactant, is shown. When using a short-chain surfactant to modify the surface of silica particles, the minimum residual concentration of diesel fuel was 2.71 mg/l at a concentration of 4% Aerosil-380 and hexylamine 57 mmol/l. Replacing the short-chain surfactant hexylamine with the long-chain CTAMB led to an 8% improvement in the quality of water purification due to an increase in the surface activity of the organic cation. The use of modified clay particles to purify water from diesel fuel showed lower efficiency compared to Aerosil-380 particles at similar concentrations of the solid phase and surfactant modifier.

    Keywords: Pickering foam, foam emulsion, diesel fuel, water purification, silica, cationic surfactant, hexylamine, cetyltrimethylammonium bromide

  • 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