The article is devoted to the study of flange beam to column connections to analyze their nonlinear behavior. In the course of the study, a simplified analytical model was created using the method of variable elasticity parameters to determine the stress-strain state of these connections. The proposed mechanical model makes it possible to predict the strength, stiffness, ductility of joints, as well as possible types of fracture and deformation mechanisms of the bent elements of flange joints. This model can be useful for engineers and specialists in the field of design and analysis of civil structures. The proposed refined component model is an analogue of the Eurocode 3 model. The paper presents a numerical experiment on modeling the junction of a beam with a column by the finite element method. A comparative analysis of the results obtained with the results of tests of flange connections of steel building structures performed by the University of Sydney (USYD) is presented.

Keywords: flange connections, flange plate, stress-strain state, method of variable elasticity parameters, component method, refined component model, finite element method, elastic-plastic state, plastic hinge, modified stiffness, bending model of flange plate

Frequency multiplexing (OFDM) methods have become the main basis for most outbred systems. These methods have also found application in modern systems of low-orbit satellite Internet (LOSIS). For example, the StarLink system uses OFDM transmission systems that use a signal frame consisting of 52 channels to transmit data. One way to increase the data rate in OFDM is to replace the Fourier transform (FT) with a faster orthogonal transform. As such, the modified wavelet transform (MWT) of Haar was chosen. The Haar MVP allows to reduce the number of arithmetic operations during the orthogonal signal transformation in comparison with the PF. The use of integer algebraic systems, such as Galois fields and modular residue class codes (MCCR), makes it possible to increase the speed of a computing device that performs orthogonal transformations of signals. Obviously, the transition to new algebraic systems should lead to changes in the structure of OFDM systems. Therefore, the development of structural models of an OFDM transmission system using the Haar MWP in the Galois field and the ICCM is an urgent task. Therefore, the aim of the work is to develop structural models of wireless OFDM systems using a modified integer discrete Haar transform, which can reduce the execution time of the orthogonal signal transformation. And this, in turn, will lead to an increase in the data transfer rate in the SNSI.

Keywords: orthogonal frequency multiplexing, modification of the Haar wavelet transform, structural models of execution of the Haar MVP, Galois field, modular residue class codes

The effect of impurities on the conductivity of the allotropic modification of phosphorene (ε-P) was studied. The quantum chemical research package Quantum Espresso was used for calculations. The study was conducted on the basis of simulation modeling. Three-dimensional structures are modeled using Quantum Espresso. The work adapted the model for two-dimensional ε-phosphorene by choosing a unit cell vector so large that interaction between the layers was possible. It has been shown that S has the smallest changes. Significant changes in conductivity can be achieved by placing F in various configurations relative to the crystal lattice, which can be actively used to create differetnt types of detectors.

Keywords: phosphorene, allotrope, semiconductor, impurity, adsorption, conductivity, density functional theory, modeling, Quantum Espresso, crystal structure

Digital twins of railway stations are necessary for planning work and taking the most effective management actions. An important factor is the compliance of the planned time costs with the actual ones. One of the tasks that are difficult to formalize at railway stations is the process of holding the rolling stock. This is due to the fact that the holding time depends on the human factor and the holding rolling stock. To create an automated station controlled by a digital twin, it is necessary to develop an automated holding system. One of the tasks in developing such a system is the problem of device location. This problem can be formulated as follows: it is necessary to place the minimum allowable number of holding devices in the controlled area in such a way that reliable holding is provided for any configuration of the rolling stock. As a tool for solving this problem, the most effective will be the use of methods of genetic algorithms. In this article, the authors consider the relevance of this study and the relevance of automating the holding of rolling stock.

Keywords: digital railway station, automation, brake shoes, UTS-380, DUZS, traffic safety.

The paper considers the operator model of the technological system for the production of caramel, assesses the stability of the subsystems and the content of the technological system. For a consistently stable caramel formation subsystem using the Shewhart map under specific production conditions, an analysis of the stability of the subsystem was carried out.

Keywords: operator model, subsystem, system integrity, process stability, control charts, average values, range

The main problems of wear of the upper layer of asphalt concrete pavement during intensive use, from the wheels of the vehicle, the roadbed of public roads are considered. The task is to increase the strength characteristics of road pavements from hot mix asphalt, taking into account the use of lime-containing components in the composition of the mineral powder. To achieve this goal, the factors influencing the increase in the operational parameters of road surfaces are considered. The use of lime-containing components with high chemical activity is substantiated. The physical and chemical properties of lime form a structured layer of bitumen in the zone of contact with mineral substances, which is resistant to the aging process. There is an increase in strength and water resistance due to the high adsorption capacity and chemical activity of lime-containing components. During intermolecular interaction in the contact zones of calcium oxide grains with an organic binder, a coagulation-condensation structure is formed. Crystallization structures are shaped like crystals and evenly distributed in the mixture before the formation of the asphalt concrete pavement, which leads to increased strength and shear resistance. According to the results of experimental studies, the road surface is characterized by increased strength and water resistance. A conclusion was made about the effect of the use of lime in the composition of mineral powders on the performance properties of road surfaces.

Keywords: asphalt concrete coating, performance indicators, strength, water resistance, structure formation, lime, calcium oxide

This work is devoted to the development of a control system for the technological process of extruding a polymer coating of pipes. In the process of work, the existing system for regulating the temperature of the polyethylene extruder zones was analyzed, and the scientific and technical literature was analyzed. The description of the technological process of extruding the outer polymer coating of a steel pipe is given, the selection of automation equipment is carried out. The main difference between a proportional controller over a proportional-integral-derivative controller was described, the optimal tuning coefficients of the PID controller were also determined using experimental methods, graphical transients were given, and the most appropriate method for controlling the temperature of the zones of worm machines was selected, due to which increasing the homogeneity and uniformity of the protective polymer layer.

Keywords: pipe polymer coating extrusion, PID controller, polyethylene, adhesive

A methodology has been developed that can be used to develop calculation and instrumental methods for determining the standards for the accumulation of solid municipal waste for retail chains under common management, having a single trade and technological process, a similar range of goods for sale and carrying out separate accumulation of secondary material resources.

Keywords: accumulation of waste, municipal solid waste, generation standard, object of a stationary trading network, cluster analysis

For prototyping virtual resources, there are modern UI/UX development applications that have the means to build highly productive interaction algorithms, for example, Figma or its promising new competitor Pixso. These programs support the joint redating of projects, and also allow planning and discussion of ideas and stages of work here, in the environment. The correctly chosen method of interaction leads to a multiple increase in productivity. One of the recognized approaches to project planning and management is the Agile design methodology.

Keywords: team, layout, prototype, website, methodology, formal language, brainstorming, frame, project, interface, plugin, editor

The work is devoted to the problems of strategic planning in the digital technology market. The aim of the work is to build a decision support procedure for choosing a strategy, based on internal (related to the characteristics of the firm choosing the strategy) and external (conditioned by the state of the market) factors. It is assumed that the elementary strategy is described by the type, direction and applied area of activity. In this case, the possibility of combining several elementary strategies is considered. The main result of the work is a procedure for choosing a combined strategy based on the application of a genetic algorithm. The use of the methodological apparatus of evolutionary calculations is due to the large number of possible options for combined strategies and the complexity of their evaluation, which makes a complete enumeration of options impractical. The final choice is made by the decision maker based on their own preferences.

Keywords: IT market, decision support, genetic algorithm

The article considers the influence of seismic load with different ballistics on aboveground steel gas pipelines of various diameters in areas of possible earthquakes. The change in the proportion of seismic load to the total load acting on gas pipelines during operation is investigated.

Keywords: seismic activity, loads on gas pipelines, analysis of seismic activity, degree of seismic hazard

The reliability of assessing the amount of accumulated waste in the context of an imperfect scientific and methodological base for standardizing MSW, in the absence of generally accepted calculation methods, is not high enough. The possibility of using cluster analysis in the formation of a statistical sample of objects of a stationary trade network in setting standards for the accumulation of municipal solid waste is shown. A methodology for the formation of a representative statistical sample of objects of a stationary trading network has been developed when setting standards for the accumulation of solid municipal waste based on cluster analysis.

Keywords: waste accumulation, municipal solid waste, MSW generation standard, stationary trade network object, cluster analysis, representative sample

The problem of developing an optimal waste management system is very relevant in many countries. To solve it, it is necessary to study the processes of waste accumulation, to systematize the factors and conditions that affect the generation of waste, to determine the features of establishing waste accumulation standards for various objects. The article discusses the features of the accumulation of municipal solid waste and the establishment of standards for their accumulation for stationary objects of the distribution network.The volume and mass values ​​of daily indicators of accumulation of MSW from a trading area of ​​a certain type and the total value of accumulation indicators (over the entire trading area) are found. The formats of retail facilities with the maximum average daily indicators of MSW accumulation have been established. Standards for the accumulation of MSW for the category under consideration have been established for 1m2 of retail space with food products, 1m2 of retail space with non-food products.

Keywords: waste accumulation, municipal solid waste, MSW generation standard, stationary trade network object, volume indicator, mass indicators

Nowadays, the System on Chip (SoC) industry is rapidly developing. One of the objectives of SoC developers is to provide the most efficient communication between computational units. One of the possible solutions is using Networks on Chip (NoC) of various topologies with different routing algorithms. In this paper, a configurable test environment designed for cycle-accurate NoC simulation as part of a SoC, used to provide statistics about network behavior during test process, is presented. The environment is designed to evaluate NoC performance as part of a specific SoC at the development stage, when there is a full or partial RTL description of the system. The environment configuration options, its application area, general scheme and calculated NoC performance characteristics are considered. As a conclusion, an example of using the environment to evaluate the performance of a specific NoC is described in detail.

Keywords: network on chip, system on chip, performance evaluation, verification

The analysis of accidents on the main gas pipelines was carried out. The mathematical dependences of the volume of gas located in a gas pipeline of various diameters are determined. A nomogram is proposed to determine the volume of natural gas located in certain sections of the gas distribution network.

Keywords: gas pipelines, accident rate, degassing, gas bleeding. gas compressibility factor