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  • Bayesian approach in justifying the number of necessary experimental measurements in environmental quality control

    Based on the Bayes approach, a representative number of experimental measurements was determined when assessing the quality of the environment, in particular, when monitoring the quality of the atmosphere and checking the compliance with the standard for the accumulation of solid municipal waste

    Keywords: Bayesian approach, quality control, experimental measurement, a priori data, a posteriori data, distribution density

  • Recognition of defects on metal alloys using OpenCV computer vision algorithms

    The purpose of this work is to develop an algorithm for recognizing shrinkage defects on metal alloys. The steps for image processing are described. When analyzing the algorithm, a description is presented for each step, followed by a software implementation. The final step, after using the methods of the algorithm, is to count the contours of the defects. To demonstrate the functionality of the software, random photos of the metal body in the section were taken, where defects in the form of gas pores can be directly observed. The software, with the correct selection of input data, processes the image with high accuracy, minimizing errors in calculating defects. Using the proposed algorithms reduces the diagnostic time. The article presents a comparative description of the manual and automated methods, showing the effectiveness of the second method in comparison with the first. To write the software, the Python 3.7 programming language was used, as well as the OpenCV computer vision algorithms library.

    Keywords: defect detection, computer vision algorithms, OpenCV, metal defects, shrinkage defects

  • Тechnical and economic justification method for energy-saving investment project

    Reducing energy consumption in the design, installation and operation of engineering networks is implemented in the process of implementing investment construction projects. An energy service contract, like any economic agreement, requires a feasibility study. When strengthening the thermal protection of a building, it is necessary to determine both the design of the fences and translucent structures, and the payback period of the investment. The objective of the research is to develop and analyze a mathematical model of heat losses depending on the characteristics of the resistance to heat transfer of walls, windows and balcony doors. Classical dependencies do not allow applying standard mathematical analysis procedures. It is proposed to use a power function that assumes the availability of differentiation. The paper substantiates the form of such a function and provides an extended analysis of the effect of changes in the resistance to heat transfer of building structures on the transmission heat losses of a building, which allows arguing for the adoption of optimal technical and economic decisions.

    Keywords: energy-saving construction project, thermal protection of buildings, indifference curves, mathematical model of heat loss

  • Comparison of statically undetectable prestressed reinforced concrete trusses

    For the statically indeterminate systems under consideration, there is an optimal ratio between the load-bearing capacity of stretched and out-of-center compressed elements, in which the required reliability will be provided at the lowest value of the mathematical expectation of an external destructive load. It should also be noted that for statically indeterminate systems, the beginning of rebar fluidity is not a sign of destruction, but only indicates the beginning of an intensive redistribution of forces in it. Therefore, the values of C, do not refer to the beginning of the rebar flow, but to the complete exhaustion of the load-bearing capacity. The reliability of statically undetectable systems, including prestressed trusses, is always higher, all other things being equal, than that of statically definable systems.

    Keywords: reinforced concrete, reinforced concrete structures, statically indeterminate systems, reliability

  • Application of monolithic expanded clay concrete in enclosing structures of country cottages with intermittent heating

    A method for determining the optimal value of the heat transfer resistance of a three-layer exterior wall of a country cottage building is presented. As an optimization criterion, the specific consumption of thermal energy for the weekly cycle of operation of the building is selected. As a result of the study of the function describing the total specific energy consumption for heat loss compensation and heating of 1 m2 of the outer wall, an analytical expression was obtained to determine the optimal value of the heat transfer resistance. Based on the obtained solution, the thickness of the monolithic expanded clay concrete used as a structural and thermal insulation material in the outer wall is optimized. An analytical relationship is obtained to evaluate the energy-saving effect due to additional insulation of the outer wall of a country cottage.

    Keywords: intermittent heating, heat transfer resistance, enclosing structure, energy consumption, heat protection characteristics

  • Modern methods for monitoring deformations of buildings and structures

    The object of the research, the result of which is the presented work, is a comprehensive system of spatial data of the railway infrastructure, within which a high-precision system of coordinates of the Russian Railways has been created, and methods definition of normal heights in the Baltic Heights System 1977. The strategy and prospects for the development of high-speed transport highways (VSM) have been described. Methods for determining normal heights at research sites are given.

    Keywords: monitoring, buildings, facilities, engineering and geodesic research, laser scanning, GNSS receivers, design, construction, observations, geodesic measurements

  • Experimental study of the direction-finding receiver of the centimeter range

    The design documentation was developed, the layout was made, and an experimental study of the direction-finding receiver was conducted. A functional diagram and a description of the design are given. The method of the experiment is given. Shows the achievement of the following parameters: operating frequency range: centimeter; the dynamic range of the signals at the entrance 48 dB; the duration of the received pulses is not less than 0.1 µs; the irregularity of amplitude-frequency characteristics of not more than 5 dB.

    Keywords: direction finding receiver, logarithmic receiver, amplitude-frequency response, amplitude response, dynamic range

  • Development of a model of passenger flow movement that is suitable for identifying hidden patterns in the processes of passenger flow creation

    A model of passenger traffic movement is proposed that is suitable for identifying hidden patterns in the processes of passenger flow creation. The passenger flow is divided into four components, for which separate passenger flow submodels are developed: quasi-deterministic passenger flow from leaving stops to points of mass attraction of passengers; stochastic hourly passenger flow from each arrival stop to different districts of the city; stochastic flow that models the distribution of passengers between final stops in accordance with the degree of popularity of stops; chaotic distribution of passenger traffic between stops with a small number of daily visits. The results of calculations of the quasi-deterministic passenger traffic submodel from leaving stops to points of mass passenger attraction are estimated.

    Keywords: passenger transport, passenger traffic models, passenger behavior patterns, modeling

  • Modern methods and algorithms for solving fuzzy distribution (transport) problems, reflected in foreign literature

    The article discusses the work of foreign authors in the field of solving fuzzy distribution (transport) problems. To solve such problems in real conditions, it is rather difficult to formalize all parameters in the form of definite numbers, therefore, the field of solving fuzzy distribution (transport) problems attracts wide attention of scientists and experts, provoking numerous successful studies. To solve distribution (transport) problems, when considering the current state of foreign literature, the main approaches have been identified, consisting in the use of pentagonal, hexagonal, octagonal fuzzy numbers, ranking, intuitive fuzzy environment, as well as the Pythagorean approach. Now it is becoming more and more important to use inaccurate data in real transportation problems. The listed approaches to solving distribution (transport) problems give a certain effect in comparison with the existing ones, therefore it is necessary to investigate solutions of fuzzy distribution problems using modern approaches and methods.

    Keywords: fuzzy transport routing problem, optimization, fuzzy methods, fuzzy numbers, heuristic algorithms, hybrid algorithms

  • Influence of mineral composition and structure of aggregates on thermal expansion of conventional and heat-resistant concretes

    The work was carried out due to the fact that the regulatory documents used in the design of structures operating at elevated and high temperatures do not take into account the peculiarities of the mineral composition and structure of concrete aggregates. This is a disadvantage of these documents, since the mineral composition and structure of aggregates can differ significantly even for materials of the same name, which can significantly affect the thermal changes in concrete. Due to the impossibility of experimentally investigating all the variety of concretes based on aggregates of various mineral composition and structure, a computational and analytical study was carried out in the work on the basis of existing methods for the analytical determination of thermal changes in concretes and their components. On the basis of these methods, the effect on the thermal expansion of concretes of the presence and amount in the aggregates of the most expanding minerals (aragonite, calcite, quartz, cristobalite, potassium feldspars, pyroxenes) and glass, as well as the average size of crystals composing mineral fillers, has been calculated and investigated. Considered are heavy Portland cement concretes on aggregates of limestone, dolomite, granite, syenite, diorite, basalt, diabase, broken clay brick, chamotte and slags. Based on the calculations, it has been established that the values of the thermal change in the volume of concrete, determined according to the normative document SP 27.13330.2017, coincide with the calculated values only for certain combinations of the mineral composition and structure of aggregates in terms of crystal sizes. In other cases, the actual thermal expansion of concrete may be less and more than the values obtained according to SP 27.13330.2017. The regularities of the influence on the thermal expansion of concrete of the content of various minerals and the average size of the crystals of minerals in the aggregates are established.

    Keywords: thermal expansion, conventional and heat-resistant concretes, aggregates, minerals, glass, the effect of the mineral composition and structure of aggregates

  • The researching of ways to increase the speed of encoding and decoding of Reed-Solomon codes

    The problem of increasing the coding and decoding speed of Reed-Solomon codes (RS-codes) is considered. The implementation of the Open JPEG encoding system library was chosen as a base implementation for comparison. This task is considered for an x86-64 environment. The paper proposes ways to improve performance both when using a standard set of instructions and when using vector instructions from the SSSE3 and AVX2 sets. A technique for comparing the speed of encoding / decoding RS-codes is described using the example of the developed library and the basic implementation in Open JPEG. An experimental study of the relationship between the parameters of RS-codes, the encoding / decoding rate, and the set of instructions used is carried out. It is shown that for any RS-code it is possible to significantly increase performance even on a standard set of instructions. A method is proposed for the dynamic selection of the encoding acceleration method depending on the instructions supported by the target computer and the parameters of the used RS-code.

    Keywords: anti-noize coding, Reed-Solomon codes, speed, vector instructions

  • Organization of formal cognitive model processing schemes

    The article offers schemes and models that allow using formal parameters and procedures to expand the capabilities of cognitive modeling and increase the level of adequacy of decisions made based on the results of modeling. The paper presents various variants of modeling schemes, which allows the researcher to perform a more versatile analysis of the system, including the analysis of dynamic effects, as well as the selection of parameters of control actions that provide the desired level of system response.

    Keywords: dynamic influence, control, simulation, formal cognitive model, formal neurocognitive network of f-euroconcept

  • Regularities of carbon monoxide in the air of the Krasnoarmeisky district of the linear city of Volgograd

    The article deals with the laws of distribution of pollutants in a linear city. The highest values of carbon monoxide concentration were determined in the near-main territories of the Krasnoarmeysky district of Volgograd. Also in this paper, the question of the dependence of the level of gas pollution in the mainline areas on various factors, which include human activity and natural, natural factors, is raised. The influence of temperature inversions on the speed of pollution propagation and their limiting value in various points of the city is considered. For the experimental part, 18 points of technical measurements of CO concentration were taken, during which compliance with the MPC standards of the samples taken was revealed.

    Keywords: linear city, district, law of distribution of carbon monoxide, transport of impurities, air pollution

  • Analysis of subsidence processes during compression compression of clay soils in the Rostov region and the Republic of Kalmykia

    Based on the results of engineering and geological survey of real construction sites in Rostov-on-Don and the Republic of Kalmykia, the dynamics of subsidence processes on laboratory samples of loess soil tested for compression according to the "one curve" scheme according to GOST 23161-2012 was studied.

    Keywords: subsidence, compression compression, odometer, loess soil, subsidence pressure, surveys, geomechanics, soil mechanics

  • Determination of electrophysical parameters of spiral inclusions in a dielectric medium to ensure chiral properties

    In this work, R, L, C - parameters of spiral structures with sizes l and S were determined to obtain artificial chiral substrates. This made it possible, given the parameters of the polarizability of the helical structures αij, to use these features to determine the conducting properties of metamaterials. The basic relationships have been determined (for determining the electrophysical parameters of spirals (left- and right-handed) that are included as chiral inclusions in the metamaterial. An algorithm for calculating conducting structures using the proposed equations is proposed.

    Keywords: biological liquid medium, dielectric constant, complex dielectric constant, loss tangent, medium conductivity, frequency response, fluctuation, frequency range, biophysical parameter