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

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

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

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 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

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

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

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

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

This article illustrates specifically how to use least squares method (LSM) and sensitivity function to cope with parametric identification problems. The object of this task is BLDC motor. The example of BLDC can justify the application of LSM and sensitivity function method for estimating nonlinear dynamic objects’ parameters, and the application for motor controlling system in particular. The model in the article is conducted by Matlab. The output is a proof to convey that the method used in solving the problem is accurate, and proves the possibility of its application in scientific and engineering field.

Keywords: parametric identification, least squares method, sensitivity function, BLDC motor, electric drive

The article deals with current methods of evaluating the organization and management in construction under conditions of uncertainty. The typology of the failure process is given, which determines the scenario of the crisis development at the enterprise. A model of forecasting and management in a crisis is proposed, and the conceptual aspects of building this model are considered. It is proposed to improve the enterprise management system based on the analysis of the economic component as a temporary function. Recommendations are given for improving the existing organizational forms of enterprise management.

Keywords: construction organization, organizational and technological solutions, reliability assessment, construction quality assessment

Questions of accounting of actors of influence on the investment and construction cycle are raised. An example of the use of BIM-technologies in construction is considered. It describes the solution of some specific problems that arise when maintaining the quality of construction of complex buildings, taking into account the possibility of introducing modern information systems, attention is paid to the peculiarities of improving the quality of work performed.

Keywords: organization of construction; quality of design, quality of construction and installation works, BIM-technology

This article investigates methods to combine multiple data-driven models for forecasting time series. This is done in order to increase the accuracy of forecasts according to the historical error signal, such that it minimises downstream costs of forecast errors.

Keywords: time series, combination of models, accuracy assessment, forecasting, forecast accuracy

Currently, in the design and manufacture of steel products operating in conditions of heavy impact-abrasive wear, not only material is given, but also the structure of the product itself. One such detail is the friction wedge of a freight wagon trolley. In the presented work, a new design of the friction wedge of the vibration damping unit is presented; technical calculations are carried out on the strength of the presented design. The safety factors of spring suspension are calculated. All calculations were performed according to the standards for the calculation and design of new and modernized railroad cars of the Ministry of Railways 1520 mm gauge. The performed calculations indicate the high performance of the developed design, the obtained values ​​fully satisfy the requirements for such products. The result of the work on creating a new design of the friction wedge of the vibration damping unit is to obtain a patent for utility model No. 194823, a drawing has also been developed (KI-000.00.00.001) and terms of reference for experimental design work (KI-000.00.00.001 TK).

Keywords: friction wedge, vibration damping unit, freight car truck, strength, reliability, durability, calculation of spring suspension, static deflection of spring suspension, coefficient of structural margin of deflection, coefficient of relative friction

The article considers examples of cities with a linear-elongated configuration. Issues of air pollution are considered, examples of components of pollutants coming from stationary and mobile sources are given. Statistical data on human diseases in the Volgograd region for the period 2008-2017 are presented. Considers the issues of monitoring for the city of Volgograd.

Keywords: linear city, highway, pollution, carbon monoxide, monitoring, monitoring posts, disease statistics, combined action, vehicles, noise, gas pollution, health, exhaust gases, length