This article discusses the practical implementation of the self sovereign system based on the technology of a distributed decentralized data registry, also known as blockchain. An implementation of the system based on the Proof of Stake (PoS) consensus-building mechanism is presented, which provides a number of advantages over alternative implementations described in the literature. The results of measuring system performance in comparison with known implementations based on Proof of Work (PoW) are presented, confirming the high efficiency of the proposed solution.

Keywords: decentralized, user-centric, identity-based encryption, blockchain, self Sovereign identity system

The article discusses the methods and approaches developed by the authors for the recommendation system, which are aimed at improving the quality of rehabilitation of the patient during respiratory training. To describe the training, we developed our own language for a specific subject area, as well as its grammar and syntax analyzer. Thanks to this language, it is possible to build a devereve describing a specific patient's training. Two main methods considered in the article are applied to the resulting tree: "A method for analyzing problem areas during training by patients" and "A method for fuzzy search of similar areas in training". With the help of these methods, it is proposed to analyze the problem areas of patients' training during rehabilitation and look for similar difficult areas of the patient to select similar exercises in order to maintain the level of diversity of tasks and involve the patient in the process.

Keywords: Recommendation system, learning management system, rehabilitation, medicine, respiratory training, marker system, domain-specific language, Levenshtein distance

This publication considers the architectural and compositional dominants of public spaces of two small historical settlements on the Don River - the Cossack villages of Veshenskaya and Razdorskaya. The author focuses on the study of the patterns of formation of the historical and cultural framework of a small historical settlement, as well as the process of development of its architectural and compositional core, which includes the public space of the center of the Cossack villages and the architectural and compositional dominants associated with it. The article provides a retrospective analysis of these dominants in the planning structure of the Cossack villages of Razdorskaya and Veshenskaya in a chronological framework from the beginning of the 19th century to the beginning of the 19th century until now.

Keywords: historical and architectural environment, architectural and compositional dominant, small historical settlement, public space, Cossack village,Cossack village of Veshenskaya, Cossack village of Razdorskaya (Razdorskaya-on-Don), project of protection zones

To create composite building materials with a polymer matrix, various fillers of both plant (wood-polymer composites - WPC) and mineral (mineral-polymer composites - MPC) origin can be used. The article evaluates the feasibility of using twelve different minerals in MPC from the standpoint of strength, cost and weight of the resulting materials in comparison with similar indicators of WPC. By sequentially considering each of the evaluated parameters, the sample of fillers is reduced by excluding combinations with characteristics worse than those of the reference material - a wood-polymer binary composite consisting of wood flour and polypropylene. It has been shown that one of the most effective mineral fillers can be waste from construction industry enterprises, as well as structures recycled during the demolition of buildings and structures.

Keywords: composite, matrix, filler, mineral, wood flour, dust, cost, volumetric weight, strength, elastic modulus, Poisson's ratio

The paper considers the possibility of using forest industry waste as a basis for the creation of biofertilizers. Of the main types of waste, sawdust, wood chips and bark are the most discussed. Taking into account the minimal change in composition, they can be used for the production of biofuels, such as pellets or briquettes. In addition, they can be used for the production of compost and fertilizers. The review of patents with a brief description of the method of processing and use of wood waste in the field of biotechnology is given The most promising for today can be considered the use of these wastes for the production of biofertilizers (when enriched with microbiological crops, as well as in the mixed part with animal husbandry and crop production waste), as well as the possibility of recultivation of disturbed areas during logging.

Keywords: sawdust, compost, biofertilizers, forest industry waste, patent search, woodworking, microorganisms

In today's world, facial recognition is becoming an increasingly important and relevant task. With the development of technology and the increasing amount of data, the need for reliable, accurate and efficient face recognition systems increases. Neural networks demonstrate high efficiency in solving computer vision problems and have great potential for improving existing mathematical models of face recognition. This paper is devoted to the study of methods for human face recognition, the Viola-Jones algorithm will be discussed in detail, which, which can be applied in the task of face recognition using neural networks. It will also analyse techniques for training deep learning models using libraries that also use the Viola-Jones algorithm and describe an algorithm for using the trained model in an API that can be used in desktop and mobile applications.

Keywords: biometric identification, human face recognition, mathematical models, face recognition methods, deep learning, convolutional neural networks, tensorflow

The article considers an approach to estimating the application coefficient of standard control system equipment on a test bench. The relevance of the evaluation task at the design stage of the test bench is shown and a description of the method for solving this problem is given. The proposed approaches can be applied both at the stage of creating a test stand and when upgrading an existing positionю.

Keywords: automatic control system, test bench, analysis of the testing process, experimental testing, standard equipment, centralized control software package, application coefficient of equipment

The transitional type of pavement of highways is widespread in Russia. At the same time, the increased estimated time between repairs cannot be fully ensured by the adoption of existing design solutions for the installation of transitional pavement pavements. This is confirmed by the dynamics of changes in the operational state, presented on the example of the road of regional importance Birakan - Kuldur in the section km 0+000 - km 25+000 in the Jewish Autonomous Region. Non-failure operation during the estimated overhaul and estimated service life of the pavement is assessed by the destruction coefficient, the limit values of which are set in the regulatory documentation. A significant decrease in the pavement destruction coefficient during the first few years of operation indicates insufficient strength and stability of the transition pavement pavement, which determines the need to develop special measures to ensure them.

Keywords: road, pavement, transitional type of pavement, pavement, destruction coefficient, overhaul life, longitudinal evenness, strength

The issues of high-quality and reliable water purification for medical needs are considered. The cleaning process is inextricably linked with the automated control of engineering systems. Water for medical purposes places high demands on the degree of filtration. In this regard, the task is formulated to ensure continuous automated monitoring and control of the cleaning process. The paper shows an algorithm for controlling the process of preliminary water purification. Based on the algorithm, a program was written in the ST language, which describes the logic of the visualization with the function of displaying and controlling the process. A fragment of the functional diagram of preliminary filtering is given. A visualization of the filter washing process is presented.

Keywords: maximum level, minimum level, backup filter, storage tank, pre-cleaning, technological equipment, visualization algorithm, functional diagram, alarm, filter washing

The article analyzes the testing time of the control system on the test bench, identifies the components of the testing time, and provides the calculation procedure for a typical test bench. The results obtained can be used to estimate the time of testing control systems at the design stage of test benches.

Keywords: automatic control system, rocket and space technology, test bench, analysis of the testing process, experimental testing, testing time

The features of the functioning of steel structures in an aggressive environment are considered, the results of a qualitative and quantitative assessment of the nature of damage to a profiled sheet are given.

Keywords: steel structures, building structures, corrosion, aggressive environment, zinc coating, corrosion rate

The article deals with the problem of disposal of the sludge formed after the treatment of wastewater at the production of chemical fibers. Sludge after sedimentation is stored in storages and pollutes the environment. We carried out a comparative analysis of existing methods of disposal of sewage sludge from chemical production, which showed that the most environmentally friendly way is pyrolysis. We have analyzed the chemical and fractional composition of ash sludge after pyrolysis. The analysis revealed that the resulting ash waste is similar to ash from coal-fired power plants, which makes it possible to use it as a microfill for paving roads or sidewalks. By selling the ash waste it is possible to reduce the payback period of the pyrolysis unit installation and reduce the ecological load on the environment.

Keywords: pyrolysis, sludge, sediment, ash, disposal

The article assesses the impact of road transport on air pollution of roadside areas of a major transport highway in Volgograd. The road-car complex makes a significant contribution to air pollution by solid particles, significantly exceeding the background value. One of the criteria for assessing the impact of dust particles on the air environment according to the World Health Organization is the mass content of particles with a diameter of less than 10 microns (PM10) and 2.5 microns (PM2.5) in atmospheric air, which is normalized in the territory of the Russian Federation by hygienic standards. The fractional composition of dust particles entering the atmospheric air was assessed by the Microtrac S3500 laser particle analyzer, the concentration by the Lighthouse 3016-IAQ particle counter. The results of the dispersion analysis are presented in the form of the Rosin–Rammler–Sperling–Bennett function of the volume distribution of particles over diameters.

Keywords: dust, particle, dispersed composition, concentration, road transport, atmospheric air, transport highway

In this study, the thermal properties of porous materials with the topology of triply periodic minimal surfaces (TPMS) of Schwarz are investigated. By generalizing the results of computational experiments, the dependencies of the thermophysical properties of TPMS materials on macrostructural parameters such as size and thickness of the elementary cell have been obtained. The properties of the most common thermoplastic polymers PETG, ABS, PLA, and PHP used in additive manufacturing have been explored. It is demonstrated that the thermal conductivity coefficients of the examined TPMS materials can be represented as a linear function of the dimensionless geometric parameter – the relative thickness of the elementary cell wall. By varying this parameter, and consequently the geometric structure of the porous medium, it is possible to obtain a material with desired thermophysical properties. Verification of the obtained finite element method results is conducted based on the analysis of mesh convergence of solutions.

Keywords: effective thermal conductivity; heat transfer; porous material; porosity; thermoplastic polymer; ordered macrostructure; Schwarz minimal surface; triply periodic surface

The possibilities of a little-studied method for obtaining nanosized materials of electronic engineering with a given substructure, the zone sublimation epitaxy (ZSE) method, are discussed. In the work, it is combined with the method of gradient liquid phase epitaxy (GLE). A specific feature is mass transfer in a two-phase medium (a solid substrate and an inert gas phase acting as a transport medium) with preliminary deposition of a matrix layer formed from the melt. A feature of the sublimation process in the study was the crystallization of low-melting iron-silicon eutectic. A mathematical model of the process was proposed and compared with the experimental results. Island structures of the composition silicon (more than 90%), iron (up to 8%) and chromium (about 1.5%) have been obtained. Their parameters and size distribution were studied. A Solver-HV scanning probe microscope and a Quanta-200 scanning electron microscope were used. The study shows that the use of sublimation transfer transients makes it possible to reproducibly form doped silicon nanolayers and transform them into regular mesostructures.

Keywords: microsize growth cell method, zone sublimation epitaxy, gradient liquid phase epitaxy, island nanostructures