The search for orthogonal and quasi-orthogonal matrices is considered as a sequence of setting initial conditions, choosing an implementation method, filtering a set of generated sequences. It is proposed to accelerate the search for matrices by pre-fixing their structure and filtering the generated sequences using the Fourier spectrum. Fixing the structure involves using the symmetry properties of the desired matrices. Filtering allows you to exclude sequences with explicit spectrum outliers when forming blocks of symmetric matrices.

Keywords: mining of matrices, Hadamard matrices, Propus conctruction, filtering sequences

The article presents a method for calculating short-circuit currents in a DC traction network. The system of group grounding of supports, considered in the article, is equipped with an additional conductor that improves the working conditions of the entire section of the electrified railway by reducing the resistance of the short circuit loop.

Keywords: group grounding of supports, short-circuit current, electrified railway, traction network, fiber-optic communication line.group grounding of supports, short-circuit current, electrified railway, traction network, fiber-optic communication line

The paper considers the types and classification of industrial PID controllers according to various types and groups. A group of linear controllers has been identified, which includes PID controllers, which are most widely used in various technical devices. Some well-known software systems that provide calculations for PID controllers are given. The transition from the mathematical notation of the trapezoidal expansion of the transfer function of the PID controller, used in the PID Tune option of the Matlab environment, to the equivalent transfer function, represented by the symbolic coefficients of the numerator and denominator polynomials, is shown. A theorem is proved that shows a one-to-one correspondence between the parameters P, I, D of the controller and the coefficients of the resulting transfer function. Flowcharts of algorithms for calculating transfer function coefficients (TF) from known values of controller parameters and calculating transfer function coefficients from known values of controller parameters are given. An illustrative example is considered.

Keywords: PID controller, transfer function, block diagram of the algorithm, Matlab environment

The article describes an approach to the operation of a data transmission network protection system against computer attacks based on a hybrid neural network. It is proposed to use a hybrid neural network as a machine learning method. To calculate the output value of neural network signals, the activation function is used. The neural network model consists of recurrent cells - LSTM and GRU. Experiments have demonstrated that the proposed network protection system for detecting computer attacks based on an assessment of the self-similarity of the system functioning parameters using fractal indicators and predicting the impact of cyber attacks by applying the proposed structure of the LSTM neural network has a sufficiently high efficiency in detecting both known and unknown spacecraft. The probability of detecting known spacecraft is 0.96, and the zero-day attack is 0.8.

Keywords: data transmission network, computer attack, neural network, protection system, network traffic, auto-encoder, accuracy, completeness, detection, classifier, self-similarity, recurrent cells with long short-term memory

The optimization of the taxable base of capital construction objects is considered, this is the desire of customers and operating organizations to manage the cost of ownership of one or another technical solution, which is certainly reasonable in modern conditions, when when making a technical solution, its full cost is estimated, including the so-called cost of ownership for the entire period of the life cycle of the object, from the formation of an idea for the creation of a future object to its decommissioning.

Keywords: collapsible foundation, protective element, flow method, wind power plant, building structures

The main provisions of the methodology for modeling organizational risks inherent in domestic companies are considered, while taking into account such important factors as the likelihood of an accident and the severity of possible consequences. It is advisable to identify organizational risks of companies and assess them before the onset of consequences; for this, indicators are presented that help prevent the occurrence of adverse events. The onset of adverse events leads the company to deviations in the main indicators characterizing the activity. The scientific problem that requires scientists to solve is the emergence of organizational risks at the strategic and tactical levels of companies, due to fatal mistakes of management. The scientific novelty of the presented research: the main provisions of the methodology for modeling the company's organizational risks are formulated; indicators are shown that contribute to the prevention of adverse events. Further research is related to the development of methods for assessing organizational risks by domestic companies, taking into account the specific, geographical features of doing business.

Keywords: organizational risks, indicators, factors, company, modeling, probability, assessment, methodology, results, events, consequences, indicators, business

The paper analyzes the thermal regime of a highly functional on-board control unit in an AMg6 aluminum alloy case and compares the obtained data with the thermal regime of a unit with a highly efficient heat sink made of composite materials. The calculation of the thermal field of the block was carried out using CAD tools based on the finite element method with a thermal application in order to assess its performance under given boundary conditions. Based on a comparative analysis of various heat-removing materials of the basic supporting structure, the least heat-stressed system was chosen.

Keywords: thermal regime, highly efficient heat removal, composite materials, on-board equipment, oxygen system, finite element method, mathematical model, computer-aided design system, electrical radio product, printed circuit board

When building complex technical systems, as a rule, the resources of an existing system are used as a basis, which may be redundant due to the lack of a clear definition of what the system is needed for. This necessitates the determination of the system intended purpose, the selection of elements for its construction and management in the process of its operation, aimed at achieving the intended purpose and optimizing the resource support used to build the system. The paper proposes an approach to building a system based on the development of its functioning profile, which characterizes the achievement of its intended purpose, modeling the process of a complex technical system functioning and evaluating the effectiveness of the profile. The use of the proposed methodology will allow, at the stage of building a complex system, to improve the quality and efficiency of designing a complex technical system by taking into account the functional needs of the system, as well as determining the amount of resources required to fulfill them.

Keywords: profile, complex technical system, criticality, system design, system construction, control process automation, functions, tasks, resource

The flow that occurs during the movement of an elevator cabin in the shaft of a high-rise building from the -4th to the 58th floor is considered. The moving elevator cabin works like a piston and pushes air in front of it out of the shaft and draws air into the shaft behind it. This effect is especially significant in high-rise buildings, which are characterized by a high speed of elevator cabins movement. The STAR-CCM+ software was used as a research method. To simulate the non-stationary problem of the elevator cabin movement, the technology of sliding meshes was used. It was found that when the elevator cabin moved at a speed of 7 m/s, the maximum pressure drops formed on the surfaces of the elevator shaft amounted to 130 Pa. It was found that the maximum flow rate of air entering the elevator shaft and from the elevator shaft into the hall due to the piston effect is about 250 m3/h. This value is comparable to the flow rates formed due to natural movement of air in the elevator shaft caused by stack effect in winter and cannot be automatically excluded from consideration.

Keywords: high-rise building, numerical simulation, piston effect, stack effect, elevator shaft

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 article discusses the process of applying a radio-absorbing coating to the surface of plastic. Vacuum plasma methods make it possible to effectively apply thin films to various surfaces. The main parameters affecting the quality and effectiveness of the properties of the applied coatings are considered.The result of the studied coatings obtained by the vacuum-plasma method showed that a sample coated with aluminum nitride, the transmission coefficient through which has not changed compared to the case of free space, is not shielding, and a sample coated with titanium metal, introducing additional attenuation of the order of 5 dB indicates the presence of absorption.

Keywords: electromagnetic radiation, thin films, application technology, radio-absorbing coating, radiation protection, magnetron.

The article discusses the design of a retaining structure in complex engineering and geological conditions, taking into account foreign and Russian regulatory requirements. The authors presented two design solutions for a retaining wall from a row of bored piles, made according to Russian and foreign regulatory prerequisites. For both construction options, the SSS parameters are determined and compared. In conclusion, it was concluded that the design of the retaining wall, made according to foreign regulatory prerequisites, turned out to be much more economical.

Keywords: retaining wall, ground anchor, calculation, protective structure, design, retaining structure, bored piles, road, stability, construction, road construction

A review of the problem of accounting for random factors in the scheduling of construction projects is considered. The problems of taking into account random factors in construction scheduling have been considered in works. However, these studies have not paid full attention to the course of construction for large projects. At the same time, scheduling problems are closely related to optimization of working hours and resource allocation in construction production. Such tasks are usually solved by considering several variants of the technological sequence of works, and the typology and variability of random factors are not fully taken into account. A number of researchers have the view that the determining factor in estimating the actual duration of construction is the reliability of suppliers and delivery of construction products. However, it is not possible to ensure the construction process in reality without interruptions in work. The main reason for this is random factors. It is suggested to take them into account on the basis of modern information technologies including artificial intelligence, stochastic approaches, probability theory and mathematical statistics.

Keywords: Construction organisation, random factors, organisational expectations, calendar modelling, stochastic search, genetic algorithms