In systems for monitoring, diagnostics and recognition of the state of various types of objects, an important aspect is the reduction of the volume of measured signal data for its transmission or accumulation in information bases with the ability to restore it without significant distortion. A special type of signals in this case are packet signals, which represent sets of harmonics with multiple frequencies and are truly periodic with a clearly distinguishable period. Signals of this type are typical for mechanical, electromechanical systems with rotating elements: reducers, gearboxes, electric motors, internal combustion engines, etc. The article considers a number of models for reducing these signals and cases of priority application of each of them. In particular, the following are highlighted: the discrete Fourier transform model with a modified formula for restoring a continuous signal, the proposed model based on decomposition by bordering functions and the discrete cosine transform model. The first two models ideally provide absolute accuracy of signal restoration after reduction, the last one refers to reduction models with information loss. The main criteria for evaluating the models are: computational complexity of the implemented transformations, the degree of implemented signal reduction, and the error in restoring the signal from the reduced data. It was found that in the case of application to packet signals, each of the listed models can be used, the choice being determined by the priority indicators of the reduction assessment. The application of the considered reduction models is possible in information and measuring systems for monitoring the state, diagnostics, and control of the above-mentioned objects.

Keywords: reduction model, measured packet signal, discrete cosine transform, decomposition into bordering functions, reduction quality assessment, information-measuring system

At present, continuous tank reactor is widely used in many different industries, and there are many control methods for this reactor. This paper presents a design method for model predictive controller (MPC) based on fuzzy model. The control object is modeled by fuzzy model (Takagi-Sugeno), the optimization problem is solved by genetic algorithm. Using fuzzy models and genetic algorithms to implement MPC controller, it achieved better quality than traditional MPC controllers.

Keywords: method of designing a model predictive controller, fuzzy model, Takagi Sugeno, genetic algorithms, multiple inputs-multiple outputs

The use of electronic signatures has recently become widespread and has become an integral part of most business processes. The electronic signature management tools offered by the cryptography vendor are not always able to satisfy all the requests of organizations. In this paper we consider an approach aimed at solving most of the problems of electronic signature management. The essence of the method consists in the combined use of both libraries of the cryptography tools developer and the capabilities of highly specialized libraries for working with cryptography and documents.

Keywords: software, electronic signature management, stamp, electronic signature visualization, information protection

The current situation in the practice of designing complex technical systems with metrological support is characterized by the following important features: a) the initial information that can actually be collected and prepared at the early stages of design for solving probabilistic problems turns out, as a rule, to be incomplete, inaccurate and, to a high degree, uncertain; b) the form of specifying the initial information (in the form of constraints) in problems can be very diverse: average and dispersion characteristics or functions of them, measurement errors or functions of them, characteristics specified by a probability measure, etc. These circumstances necessitate the formulation and study of new mathematical problems of characterizing distribution laws and developing methods and algorithms for solving them, taking into account the constraints on the value and nature of change of the determining parameter (random variable) of a complex technical system. As a generalized integral characteristic of the determining parameter, the law of its distribution is chosen, which, as is commonly believed, fully characterizes the random variable under study. The purpose of this work is to develop a method that allows constructing distribution laws of the determining parameter of a complex technical system using the minimum amount of available information based on the application of Chebyshev inequalities. A method for characterizing the distribution law by the property of maximum entropy is presented, designed to model the determining parameter of complex technical systems with metrological support. Unlike the classical characterization method, the proposed method is based on the use of Chebyshev inequalities instead of restrictions on statistical moments. An algorithm for constructing the distribution function of the determining parameter is described. A comparison is given of the results of constructing distribution laws using the developed method and using the classical variational calculus.

Keywords: Chebyshev inequalities, complex technical system, design, determining parameter, characterization of distribution law

In operational diagnostics and recognition of states of complex technical systems, an important task is to identify small time-determined changes in complex measured diagnostic signals of the controlled object. For these purposes, the signal is transformed into a small-sized image in the diagnostic feature space, moving along trajectories of different shapes, depending on the nature and magnitude of the changes. It is important to identify stable and deterministic patterns of changes in these complex-shaped diagnostic signals. Identification of such patterns largely depends on the principles of constructing a small-sized feature space. In the article, the space of decomposition coefficients of the measured signal in the adaptive orthonormal basis of canonical transformations is considered as such a space. In this case, the basis is constructed based on a representative sample of realizations of the controlled signal for various states of the system using the proposed algorithm. The identified shapes of the trajectories of the images correspond to specific types of deterministic changes in the signal. Analytical functional dependencies were discovered linking a specific type of signal change with the shape of the trajectory of the image in the feature space. The proposed approach, when used, simplifies modeling, operational diagnostics and condition monitoring during the implementation of, for example, low-frequency diagnostics and defectoscopy of structures, vibration diagnostics, monitoring of the stress state of an object by analyzing the time characteristics of response functions to impact.

Keywords: modeling, functional dependencies, state recognition, diagnostic image, image movement trajectories, small changes in diagnostic signals, canonical decomposition basis, analytical description of image trajectory

The development of methods for calculating structures made of ultra high-performance steel fiber-reinforced concrete (UHPC) in terms of strength and deformations is an important step towards the introduction of this innovative material into the practice of design and construction. This paper presents the results of finite element modeling of the operation of UHPC I-beam in the area of action of shear forces. The SMM model integrated in the OpenSees framework application is used for the walls of beams under conditions of flat stress. The authors have added new classes of materials that implement the averaged deformation laws of UHPC (with and without fiber) and the reinforcement placed in it. The calculations showed good convergence with the authors' own test results of the UHPC I-beams, as well as with the results of experiments by other researchers.

Keywords: shear strength, shear force, ultra high-performance steel fiber-reinforced concrete, I-shaped beams, OpenSees

The choice of the method of force calculation of building structures is preceded by an analysis of the static determinacy and immutability of the rod system using structural formulas, while for different types of structures - for beams, trusses, frames, arches, etc. - sources offer different formulas. It is shown that for the structural analysis of all rod systems it is sufficient to determine the degree of structure anomaly using the formula of P.L. Chebyshev. The development of the linear-monad theory of structure makes it possible to formalize the dependence of the number of rods and hinges on the number of external and internal contours in the synthesis of both normal and anomalous structures

Keywords: beam, truss, frame, arch, structure, analysis, synthesis, immutability, definability, degree of anomaly, rods, system, contour, monad, hinge

The presented article analyzes modern ways of qualitative assessment of agricultural territories in order to identify the existing principles to order and assess the prospects of development of such territories within the projected boundaries of rural network structure (rural agglomeration). The hypothesis about the key principles to which the ways of qualitative assessment of territories for the purposes of its urban development within the rural agglomeration should be prepared is presented.

Keywords: rural network structure, rural agglomeration, qualimetric landscape method, functional belonging criterion

The organization and management of infrastructure construction has a direct impact on the level of comfort of residents, safety in the city, and the efficiency of the functioning of the city economy. In this article, based on an integrated approach, various features of the development of road and transport infrastructure in large cities are studied under the condition of their expansion in the process of urbanization, where roads play a connecting role between individual areas of the city and neighboring settlements in the common single space of the agglomeration.

Keywords: road and transport infrastructure, sustainable development, urban space, agglomeration development, urban development

The situation of occurrence, identification and management of risks arising during the construction process is analyzed. Uncertainty of decision-making in construction projects involves the creation of methods that ensure the reliability of decisions and their effectiveness. Such a method was developed in the Russian Project Management Association. The paper provides an example of using this method on a real construction site. An analysis of risks arising during the implementation of a construction project was conducted, a risk map was created for this project and the PERT method was applied when creating a calendar plan.

Keywords: uncertainty, risk event, probability, risk, damage, danger, reliability, risk analysis, investment and construction project, PERT method

This article discusses the use of dolomites from the Bosninsky deposit in the production of building materials and products. This topic is very relevant at the present time, as the construction industry is developing, new types of structures are appearing, higher requirements are imposed on the physical and mechanical properties of concrete mixtures. Large volumes of concrete mix production require the use of local component deposits to improve technical and economic performance.

Keywords: construction, building material, dolomite, environmental pollution, ecology, concrete mix, new technology

Within the framework of the urban environment, the laws of distribution of the concentration of fine dust PM2.5, PM10 along road sections have been obtained. These data are necessary to assess the probability of exceeding the maximum permissible concentrations and to improve monitoring and control systems for atmospheric air. The analysis of the key factors influencing the content of PM2.5 and PM10 particles in the air of the territories adjacent to the roads has been carried out. Regression equations for total dust, PM2.5 and PM10 dust were obtained, allowing us to conclude that the concentration of PM2.5 and PM10 depends on total dust. The analysis showed that the mass content of PM10 in total dust pollution ranges from 73 to 81%, and the concentration of fine dust PM2.5 varies within two narrow ranges of about 11.6 and about 7 microns. A study of the proportion of PM2.5 of the total concentration showed that it is on average about 20%.

Keywords: dust, emissions, concentration, atmospheric air, roadway, climate, linear city, correlation coefficient, influencing factors

The analysis of ultrasonic effect on mixing solutions and hydrophobization of solid phase in suspensions for construction purposes is carried out. It is shown that ultrasonic treatment leads to an increase in the mass content of particles with a radius of 2-7 μm in the mixing solution, which contributes to an increase in the relative tensile strength of the samples obtained on its basis. Ultrasonic treatment of suspensions with the same relative degree of hydrophobization of the solid surface led to different contact angles of wetting of solid particles: Ө = 120, 450, 930, 69.40 for clay, cement and silica particles. Ultrasound leads to a significant decrease in the volume fraction of liquid in a three-phase foam stabilized by hydrophobized clay particles, compared to the syneresis process in a gravitational field.

Keywords: three-phase foam, silica suspension, clay, ultrasound, mixing solution

Based on the results of experimental studies of the propagation of bending waves, the ability of the developed technique to assess the strength of a brick treasure is considered. A comparative analysis of the strength of the masonry was carried out using different methods (L.I. Onishchik formula, Eurocode 6). According to the correlation dependencies between the velocity of propa-gation of elastic waves and the strength of masonry, the presented practical data made it possible to prospectively evaluate the method using bending waves in the survey of buildings and struc-tures.

Keywords: experimental studies, brickwork, elastic waves, bending wave velocity, strength

Анализируется методика определения напряженно-деформированного состояния металлических опор линий электропередач при технической экспертизе объектов электросетевого хозяйства. Даётся пример расчета с использованием автоматического программного комплекса ЛИРА. Определяется наиболее напряженные участки конструкций. Расчётным способом подтверждается гипотеза о том, что трехгранное поперечное сечение траверсы портальной промежуточной опоры ВЛ 500 кВ экономичнее (эффективней) чем четырехгранное (классическое) поперечное сечение.

Keywords: building structures, metal structures, energy facilities, stress-strain state, technical expertise

The article is devoted to the issue of making organizational and technological decisions when the stock of information for alternatives to choosing the required tasks is either very small, or they are changing drastically. Since it is not easy to make an organizational and technological business decision due to the fact that it is not clear what the result will be, it is proposed to use game theory in conditions of uncertainty. What kind of decision will be made and which of the available strategies the designer will adopt depends on what economic effect will be obtained as a result of the implementation of the organizational and technological solution being developed. Game theory is a special class of mathematical models for decision-making under specific conditions. By choosing solutions in the wake of uncertainty, game theory formalizes possible knowledge about the course of action of the participants in the game in certain conflict situations and allows you to mathematically substantiate knowledge about a rational course of action in certain conditions. When constructing construction projects in environmentally unfavorable conditions, the risk matrix is compared and the best option for the development of a construction project is determined.

Keywords: construction and technical expertise, reliability, organizational and technological solutions, diagnostic methods, efficiency.

The presented article analyzes modern ways of qualitative assessment of agricultural territories in the framework of interaction within the boundaries of zones of influence of rural network structure, structural and functional interaction within such phenomenon as rural tourism, taken together and in the context of individual principles and directions of it in the projection of the territories of the reference settlement and the surrounding area.

Keywords: rural network structure, rural agglomeration, rural tourism, ethno-tourism, green (village) tourism, agrotourism, gastronomic tourism

The article deals with the influence of complex mineral additive "chemical water treatment sludge + flask or fly ash" on the frost resistance of building mortars depending on the redispersible polymer powder dosage from 0 to 3%. According to the results of research after 100 freeze-thaw cycles, the condition RF/R0 > 1.2 is met, and the k value according to clause 5.2.4 of GOST 10060-2012 after 100–125 freeze-thaw cycles ranged from 0.94 to 1.73, the minimum value of the relative modulus of elasticity EF/E0 = 0.97, and the residual expansion deformation did not exceed 0.03%. Building mortars with fly ash have higher frost resistance according to the bending strength criterion in comparison with mortars with flask. The frost resistance criterion for bending strength is more “strict” than the criteria according to GOST 10060-2012. It is not advisable to use a dosage of RPP greater than 2% for the production of building solutions with increased frost resistance requirements.

Keywords: frost resistance of building mortars, frost resistance criteria, redispersible polymer powders, compressive and flexural strength, elastic modulus, permanent expansion deformation

The paper studies the dynamic-mechanical characteristics of styrene-isoprene-styrene, polybutyl methacrylate, thermoplastic polyurethane block copolymers and their blends by dynamic mechanical analysis. It is found that blending of several types of polymers allows to extend the range of effective vibration absorption. A combination of polymers with high damping properties over a wide temperature-frequency range was determined. The influence of vibration frequency on dynamic-mechanical properties of composites has been investigated.

Keywords: polymer composite material, dynamic mechanical analysis, polybutyl methacrylate, thermoplastic polyurethane, styrene-isoprene-styrene block copolymer, vibration absorption, damping material, glass transition temperature

The requirements for the energy efficiency of building structures are based on the balance of costs for their manufacture, operation and the effect that is achieved by saving heat. In conditions of relatively low cost of energy carriers, the use of seamless insulation systems, including those based on light or heat-insulating plasters, becomes expedient. The developed facade light plaster system has, at an average density of 400–500 kg/m3, adhesion strength to the substrate of 1.3–1.6 MPa; compressive strength of 4.7–5.5 MPa; frost resistance of 50 cycles. The system has thermal in-sulation up to 0.12 W/(moС), which, with a plaster coating thickness of 50 mm and a thermal resistance of the main structure of 1.6-2.0 m2oС/W allows you to obtain a system with a total thermal resistance of up to 2.3 m2oС/W, which fully meets the conditions of comfort or technological requirements.

Keywords: adhesive strength, energy efficiency, seamless insulation, thermal resistance

On the basis of the analysis of tourist infrastructure objects location the influence of tourist flow seasonality on the number of temporary population of resort towns is shown. The relationship between the level of urban infrastructure development and seasonality of tourist flows is revealed.

Keywords: urban planning objects, engineering and transportation infrastructure, temporary population, tourist flow, seasonality, types of tourism

In the article, a floating liquefied natural gas plant located on a marine gravity platform in the Murmansk region was chosen as the object of research. The results of the development and selection of optimal concrete compositions using fiber fillers and modifying additives are presented. A set of works has been performed to determine the effect of basalt fiber fibers, as well as plasticizing additives on the structure and strength of fine-grained fiber concrete. Their advantages are shown and proposed for use in the constructions of tank hulls and other objects on a marine gravity platform.

Keywords: fibroconcrete, gas storage tanks, gravity platform, basalt fiber, superplasticizer

This work is devoted to the study of the possibility of determining heart diseases on the basis of 13 categorical and numerical signs. We present a detailed analysis of the dataset, including dividing the data into training and test samples, dividing features into numerical and categorical, applying 4 different classification algorithms, checking the quality of the model using two techniques – delayed sampling and cross-validation. To assess the quality of the model, we pay attention to the value of the recall metric and the error matrix built on the test dataset from the deferred sample or on each test fold when using cross-validation. The results of the study are important both for a deep understanding of the relationship between certain medical indicators and heart disease, and for the development of effective methods for predicting them in the presence of individual symptoms.

Keywords: cardiovascular diseases, classification task, quality metrics, cross-validation, recall, machine learning, random forest