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  • Tumor localization in case of breast cancer according to microwave thermometry using artificial neural networks

    This work was carried out as part of research on the development of methods for the intelligent analysis of medical thermometric data. These methods are designed to create a consultative intelligent system for the diagnosis of breast cancer. In this work, an artificial neural network has been obtained, which allows localization of a tumor according to microwave thermometry data. The network uses the architecture of deep belief networks. In cases where the tumor does not coincide and is not near the hottest point of the breast, the neural network can reach an accuracy of over 56% on test samples. This result exceeds the previous one by 13%.

    Keywords: microwave thermometry, breast cancer, mammology, tumor localization, fidelity, data mining, artificial neural networks, deep learning, thermometric diagnostic features, cross-validation

  • Model of distributed processing of requests by agents of decision support systems

    The article deals with modern research in the field of decision support. A model of distributed processing of requests by agents of decision support systems is proposed. The main components of the model are considered. An algorithm is built on the basis of the proposed model. A step-by-step description of the algorithm's actions is given. The main planned results have been identified.

    Keywords: decision support systems, intelligent agents, request processing, decision support model

  • Automation of engineering data analysis of urban transport systems

    The article discusses the automation of the process of engineering data analysis of urban transport systems using the freely distributed machine learning tool KNIME. The real example of an algorithm for the primary automated processing of data on transactions of public transport passengers been developed. The results can be converted into an analytical report. The advantage of the proposed solution is implementation by urban transport enterprises without software code and additional costs.

    Keywords: urban transport system, KNIME, data analysis, transactions, passenger, automation of the research process

  • Calculation of input reactive powers in power systems according to given voltages

    The article considers variants of arrangement of various reactive power compensation devices, the choice of location of which took into account both modes of operation of power grids and voltage levels in the nodes. Mathematical modeling made it possible to form an optimal calculation algorithm based on a multi-criteria approach, taking into account the possible voltage increase at the corresponding substations. However, this approach is accompanied by some increase in active power losses, so the final conclusions should be based on expert procedures.

    Keywords: reactive power compensation, mathematical modeling, installation site, power losses, multi-criteria approach, calculation algorithm, power system, substation, compensating devices

  • Comparative analysis of the use of a neural network in the problem of identification properties of materials

    The article is devoted to the use of artificial intelligence tools to solve technical problems in the construction industry. It is noted that the use of neural networks will allow taking into account the behavior of materials in various experimental conditions. The authors present a comparative analysis of approaches to neural network training, in particular, the structures of multilayer and LSTM networks are considered. It is established that LSTM networks are more effective in solving problems of identification properties of materials.

    Keywords: neural network, non-destructive testing, identification task, multilayer network, LSTM network, impact indentation, indentation, strength properties of materials, neural network technologies, statistical distribution

  • Synthesis of an electric drive control system with Permanent Magnet Synchronous Motor

    This work is devoted to the synthesis of a Permanent Magnet Synchronous Motor (PMSM) electric drive control system by the method of subordinate control systems. The mathematical model of PMSM is constructed in the d-q coordinate system rotating with the rotor. The structure and parameters of the current controllers and the rotation speed controller are determined. A model of the PMSM subordinate control system in the Matlab-Simulink environment has been developed. It is shown that the quality of the transient process of the current loops id, iq depends only on the value of the uncompensated time constant Tm. The effects of the Tm value on the operation of the rotation speed control system are highlighted. It is established that the optimal choice is the value Tm = 1, which ensures the performance of the PMSM electric drive control system, as well as an acceptable value of the inrush current.

    Keywords: PMSM, electric drive, control system synthesis, method of subordinate control systems, current control, speed control, rotation speed control

  • Influence of a heat source from ignition on the calculated combustion curve of polyethylene foam in a fire in a compartment

    This article analyzes the calculated fire curve in accordance with the ignition heat source in the compartment. To predict the calculated fire curve, the exponential equation proposed in the previous study was compared with the heat release rate measured in a fire experiment. The lag index, which is the main factor used to predict the time it will take to reach the maximum heat release rate, has decreased in proportion to the ignition heat source.

    Keywords: fire calculation curve, pipe insulation, ignition heat source, deceleration index, heat release rate

  • Numerical analysis of heat transfer in a multi-pipe configuration for various mixtures of liquids

    In this article, we investigate the effectiveness of using multiple pipes for heat dissipation. The study assumes laminar flow under steady-state conditions. Various mixtures are numerically investigated at different flow rates. Various nanofluids flowing through multiple parallel pipes have been numerically investigated to study the effects of temperature rise. Thanks to the benefits they bring to the cooling process, nanofluids have opened up a new way to improve the performance of thermal systems. A typical nanofluid consists of a base fluid, which is usually water, and nanoparticles.

    Keywords: heat exchanger, flow tube, nanofluid, bottom heating, coefficient of friction, pressure drop

  • On the influence of some technological factors on the quality of concrete of monolithic reinforced concrete structures

    When accepting finished reinforced concrete structures, incl. monolithic, they are subject to requirements for strength, stiffness, crack resistance and durability. The quality of a monolithic reinforced concrete structure depends on the quality of work, the quality of materials, the quality of design solutions and the quality of regulatory documentation. According to SP 70.13330.2012, clause 5.18.1, "when accepting finished concrete and reinforced concrete structures ... you should check ... the quality of concrete for strength, and, if necessary, for frost resistance ...". Particular attention is required for massive monolithic reinforced concrete structures, during the construction of which, due to temperature-shrinkage deformations, it is possible to form an own stress field that exceeds its strength indicators at the stage of formation of the concrete structure, which may result in early cracking with subsequent development of cracks, which will not only negatively affect operational properties of the structure, but in principle can raise the question of the impossibility of its operation. The quality of concrete of a monolithic reinforced concrete structure is determined by both recipe and technological factors, the assessment of the degree of influence of which is an urgent task.

    Keywords: massive monolithic reinforced concrete structures, crack resistance, durability, frost resistance, temperature-shrinkage deformation

  • Technical science. Building and architecture

  • Substantiation of the parameters of technological schemes for the construction of mine shafts by mechanized tunneling complexes

    Over the past 35 years, long-distance wells in Russia and the CIS countries have been drilled and blasted. The big disadvantage of this technology is the lack of the possibility of combining the most labor-consuming tunneling processes in the borehole bottom: drilling and blasting operations and rock removal. Because of this, the average rate of shaft construction did not exceed 30-50 m / month, which is 2-3 times lower than when driving horizontal and inclined workings.A promising direction for solving this problem is the widespread introduction of mechanized complexes of a new generation of domestic (SPKV, ASP) and foreign (Herrenknecht AG, etc.) production in deep hole drilling. However, their wider implementation is restrained by a number of undeveloped issues related to the justification of a rational field of application and parameters of an effective technology of shaft sinking with mechanized complexes.The article discusses the concept of a mechanized technology of shaft sinking with variable, technically and economically justified speeds, implemented within the framework of the flow organization of the construction of a complex of shafts. The main stages of designing the flow method are considered and an algorithm for determining the optimal speed of mechanized shaft sinking in various mining conditions is presented.

    Keywords: mine, shaft, construction, speed, flow method, productivity, technological scheme, field of application

  • Analysis of the technical and economic efficiency of low-rise construction based on Canadian technology

    The article discusses several types of wood frame house construction technology, primarily "Canadian technology". The rate of increase in construction in Russia is estimated. The structural materials of external enclosing structures used in frame housing construction are compared with the most commonly used components for construction. A comparative assessment of heat losses in percentage ratio during the operation of wooden frame houses and traditional ones is given. The pros and cons of frame housing construction are considered. A detailed analysis of the costs of construction and operation of wooden frame houses was made.

    Keywords: frame house construction; Canadian technology; building materials; dynamics of price changes

  • Statistical analysis of studies of steel cylindrical mesh shell

    The article discusses the statistical analysis of the stresses and displacements obtained which are determined by conducting physical experimental studies and are based on the developed calculation methodology. Due to the fact that the model was tested in laboratory conditions, the scale factor was taken into account and the coupling equations for the transition from the model to nature were compiled. The degree of discrepancy between the actual and calculated values of loads is taken into account and the characteristics necessary for statistical analysis are determined. The relations of stresses and displacements are given, taking into account the inaccuracy of the calculation, deviations of internal force factors and errors in the rigidity of the nodes. The inaccuracy in determining the geometric parameters and the modulus of elasticity of the material is justified. Sufficient reliability of the results was obtained taking into account the complex of all adverse factors.

    Keywords: cylindrical mesh shell, statistical analysis of results, stress, displacement, deviation

  • About formation of life cycle model of underground structure

    This article discusses the approach being developed, the option of life cycle formation using the example of underground structure. The most recent life cycle model used in foreign countries is considered. And based on this model, the developed scheme of the life cycle model of the underground structure is presented.

    Keywords: Life cycle, BIM, TIM, underground facilities, modeling, information construction, redevelopment, monitoring, GIS

  • Monitoring of acidic impurities in the atmosphere of urbanized areas and forecasting environmental risks for the population

    Monitoring of atmospheric air in settlements allows you to control the environmental situation there and predict environmental risks for the population. It is known that acidic impurities in the atmospheric air of urban areas affect the human respiratory system. The proven relationship between acidic aerosols from the atmospheric air and the functioning of the human respiratory system indicates the relevance of studies of monitoring acidic impurities in the atmospheric air in order to predict environmental risks for the population. In this regard, the purpose of the study was to monitor the aerosol acidity indicator in the residential area of ​​the Svetly Yar Republic (Svetloyarsk district of the Volgograd region) for the spring-summer period in 2019 and predict environmental risks for the population. The material for the study was aerosol particles from the leaves of apricot trees (Prunus armeniaca) from the village of Svetly Yar (Svetloyarsk district of the Volgograd region), from which aerosol suspensions were prepared and which were studied in terms of acidity (pH). The studies carried out made it possible to identify acidic impurities in aerosols in the village. Light Yar (pH = 4.56 + 0.028). This fact indicates the environmental risks for the population associated with the acidic environment of aerosols, since it is known that acidic air pollution can aggravate asthma, promote the development of bronchospasms, and inhibit the respiratory system. It is required to identify sources of pollution in order to develop environmental measures to protect the population from acidic impurities in the atmosphere.

    Keywords: monitoring,aerosols, acidity, pH, urban environment, environmental risks

  • Influence of ground slag of steelmaking production on the properties of a composite slag-alkaline binder

    The hardening of steel-making slags is slow and the strength properties of the cement stone do not provide the specified operational properties. By creating an optimal composition (steelmaking slag + blast furnace) and chemical activation, a composite material with high strength is obtained. The compressive strength of concrete samples at the age of 28 days of hardening in a normal hardening chamber is 28 to 54 MPa. Caustic soda and sodium silicate were used as a chemical activator of hardening. The greatest strength is provided by the ratio of chemicals as NaOH: Na2 SiO3 × nH2O = 1: 1 and at a dosage of 8% of the mass of the composite slag-alkali binder. The optimum ratio of ground granulated blast furnace slag and steelmaking slag is 3: 1 to obtain high compressive strength and minimum water absorption in the early stages of hardening.

    Keywords: steelmaking slag, blast furnace slag, homogenization, hardening activator, hydration, strength

  • Improvement of earth works when constructing multi-storied operated parts of building under the conditions of dense urban development

    The article proposes a special device to transport earth when building an underground part by the «top-down» and «top and down» technique. The developed device is fully electrically powered. The proposed technology enables to completely exclude nonproductive movements of excavating and transportation devices to relocate the earth from the working site to the dumping site onto trucks above ground. The device is adapted to work as part of the production line when realizing the “top-down” and «top and down» technology. To exclude load lifting mechanisms for lifting and dumping of the earth onto the trucks above ground, it is proposed to use two lifting rails with hoisting equipment fixed on a metal frame.

    Keywords: “top and down” technology, earth works, excavation works, subsurface part of a building, earth movement, tier of a subsurface part of a building

  • Fibroconcrete compositions for floor coverings in the construction of industrial and civil structures

    The results of the development of compositions of fibroconcrete floor coverings and the technology of their preparation for use in structures during the construction of industrial and civil structures are presented. The effectiveness of the use of polymer and basalt fiber fibers, as well as plasticizing additives in the manufacture of fine-grained fiber concrete is substantiated. As a result of the conducted experiments, the composition of fine-grained fiber concrete with the use of basalt fibers as fillers is proposed. Based on the calculation of the estimated cost, it was found that the use of fiber fibers in the concrete mixture instead of laying metal mesh allowed to reduce labor costs by about 2 times, reduce the amount of binder, and also improve the performance characteristics of floor coverings by increasing crack resistance and corrosion resistance.

    Keywords: floor coverings, fiber-concrete mixture, superplasticizer, basalt fiber, strength

  • Analysis of buildings of educational institutions of the city of Rostov-on-Don

    The analysis of school buildings constructed in the city of Rostov-on-Don is carried out. The features of their construction are considered. An assessment of the need for repair work and the construction of new schools has been carried out.

    Keywords: construction, school facility, reconstruction, architecture, number of floors, student capacity, wall material, heritage sites, Rostov-on-Don

  • About errors of design of building constructions

    According to statistical data of error of design of building constructions are one of the main reasons for accidents of buildings and constructions of different function. In article results of inspection and testing calculations of load-carrying structures of covering of industrial building are considered. It is established that the mistakes made at design and mounting of metal roof frames of the building have led to change of their constructive scheme and redistribution of efforts in rods. Mass loss of stability the overloaded compressed elements has turned out to be consequence of it. The analysis of similar situations allows to avoid their repetition, not to allow emergence of emergencies and unjustified increase in material and financial expenses in use of objects.

    Keywords: design errors, defect of mounting, constructive scheme, overload, metal frаme work

  • Construction technology in pits up to 5 meters deep

    The article provides the definition of a deep pit. The authors substantiated the need for fixing the walls of excavations with a depth of 3-5 meters and the development of methodological recommendations and reference data for the selection of optimal methods and structures used for enclosing the excavation. Wooden sheet pile is the most affordable and technically simple solution for fixing the walls of excavations with a depth of 3-5 meters. The authors calculated the structural characteristics of a wooden sheet pile for various soil conditions according to the method proposed by Professor E.K. Jacobi. The results are presented in a reference table, a fragment of which is given in the article. The developed reference data make it possible to assess the feasibility of using a wooden sheet pile without additional calculations. Engineers can determine the required cross-sections of the fence and struts, the immersion depth of the wooden sheet pile, the step of installing the struts according to the reference data.

    Keywords: deep pit, fixing the walls of the pit, sheet pile, E.C. Jacobi method, pit collapse, pit slopes, earthworks, work safety, wooden sheet pile, accident

  • "Small" leaks of oil products in city Volgograd and their influence on atmospheric air pollution

    The publication considers "small" leaks of oil products in city Volgograd, which are mainly represented by gasoline leaks at gas stations and leaks of technical liquids from vehicles in parking lots. The properties of these leaks are investigated. The regularities of oil products entering the air from "small" leaks are obtained. Measures are developed to improve the efficiency of collecting leaks. The design of a container for storing and accumulating waste generated as a result of collecting "small" leaks of oil products is proposed and tested. The obtained test results showed that the proposed container design can significantly reduce atmospheric air pollution compared to the commonly used container design.

    Keywords: oil products, leaks, properties of "small" leaks, gas station, parking lots, wastes, container, city

  • The relevance of the use of basalt fiber in modern construction

    The purpose of the article is to study the material on the topic "Basalt fiber", to generalize the studied material and the accumulated experience on the given topic. The article discusses the advantages, disadvantages, problems of use and achievements in the study of basalt fiber used for the production of building materials as a reinforcing component. The analysis of the average cost of basalt fiber in comparison with other types of fiber is carried out, a conclusion is made about the advantage of using basalt fiber. General conclusions have been made about the advisability of using basalt fiber for the production of building materials, and unexplored areas of using this type of fiber have been identified.

    Keywords: basalt fiber, reinforcement, stress-strain states, compression, tension, bending, shear, deformation, adhesion

  • Improvement of the environmental management system of electric power industry organizations

    The article discusses the features of environmental safety management systems of organizations in the electric power sector, and also presents an approach to their improvement. The authors substantiate that an important aspect of improving the environmental safety of electric power companies is the integration of quality and environmental management processes in the organization. Based on the analysis of scientific literature and the regulatory framework, the problems of integration of environmental management systems, quality management and organization management are identified. As one of the approaches to improving the environmental management system of electric power industry organizations, a management model of an environmentally-oriented organization based on the PDCA cycle and a quality management system, as well as scientifically based principles of its construction, is proposed. The key advantages of the model are: an expanded methodological base in comparison with the models of environmental management and quality management based on the Deming сycle "Plan-Do-Check-Act" the possibility of effective integration with the general management system; decision-making based on various factors of the external and internal environment of the organization.

    Keywords: environmental safety, integrated management model, environmental safety management in the electric power industry, Deming сycle

  • Installation technology of civil buildings' large-span structures on the example of erection of multifunctional sports complex truss

    The article provides the information about the erection procedure of a 50.3 m span truss of a multifunctional sports complex in Nefteyugansk, Russia. The expediency of the considered large-span structure in finished form was substantiated by authors. The advantages and disadvantages of the options for choosing the erection procedure were analyzed in detail. Both types of finished truss erection were simulated in Autodesk Revit software: erection with one crawler crane and with two truck mobile cranes. The advantages and disadvantages of these two methods were observed. Erection process with two truck mobile cranes Liebherr LTM 1160-3.1 does not require complicated motions on the construction site, however it is imposiible with intalled beams between coloumns. For erection process with one crawler crane Liebherr LTM HS 855 HD temporary roads is not necessary, but this crane needs special transport for delivery on site.

    Keywords: large-span structure, truss, erection in finished state, suspended cantilever method, jib crane, mobile crane, crawler crane, lifting equipment