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  • Structure and metrological properties of combined pathospecific measuring device for glaucoma diagnostics

    The article presents and substantiates the structure of the original combined pathospecific measuring device for the diagnosis of glaucoma, which will allow for a comprehensive analysis of the hydro- and hemodynamics of the eye and thereby improve the quality of glaucoma diagnosis. Based on this structure, a detailed metrological analysis of this installation as a means of biomedical measurements was given in the work. Brief conclusions on the work are given and prospects for the further development of the project are determined.

    Keywords: combined pathospecific measuring device, tonometry, rheography, sphygmography

  • Flame retardant coatings: a review of issues lowering down attraction of private venture investment

    The increasing complexities in the development of new fire-protective coatings hinder the attraction of private investments and impede the progress of innovation. The review provides an overall picture of the research and specifically illustrates the extraordinary diversity of their directions and explains the inherent reason for such diversity. The goal of this review is to establish an information foundation for a critical analysis of the feasibility of private investments in developments in this field and to show some possible ways. The wide range of choices for specific components in fire-protective coatings and the diversity of mechanisms they employ result in a factorial number of possible combinations. The variety of properties of these components and the complexity of their interactions make it difficult to assess the outcomes of their selection unequivocally without conducting experiments during the development of new materials. Therefore, confident prediction of the results of new research is extremely challenging. As a consequence, there is a broad spectrum of directions and sub-directions in ongoing developments. Summing up the results of these investigations is further complicated by the difficulty of testing materials for aging parameters and resistance to external influences. The wide range of choices for specific components in fire-protective coatings and the diversity of mechanisms they employ result in a factorial number of possible combinations. The diverse properties of these components and the complexity of their interactions prevent a definitive evaluation of the results of their inclusion in the composition prior to conducting experiments in the development of new materials. Therefore, confident forecasting of the results of new research is extremely challenging. As a consequence, there is a broad range of directions and sub-directions in ongoing developments. Summing up the results of these investigations is further complicated by the difficulty of testing materials for aging parameters and resistance to external influences. The high uncertainty in forecasting the prospects of specific developments stimulates the advancement of simulation methods for compositions and coating manufacturing technologies, as well as the prediction of their effectiveness, etc. However, these methods only provide a partial increase in the reliability of expectations. A more thorough execution of a feasibility study is recommended to substantiate venture investments. One of the additional approaches capable of enhancing its credibility is the utilization of non-traditional specialized methods for researching patent information.

    Keywords: fire-protective coatings, specifically illustrates the extraordinary diversity, prospects of specific developments stimulates, simulation methods for compositions and coating manufacturing technologies

  • Automated system for issuing bank guarantees based on forecasting the execution of government contracts

    In order to provide information support for decision-making on the issuance of bank guarantees for the execution of a contract in the field of public procurement, it is important for banks to obtain historically accumulated information on the execution of government contracts. This is necessary to assess the possibility of the supplier's performance of his future contract. This can be done by collecting and aggregating information about contracts from the Unified Information System in the field of procurement. The paper proposes to use IT technologies and data analysis to predict the performance of the contract and identify bona fide suppliers. In the work, a selection of primary data on contracts was formed for modeling using the parsing of the FTP server of the Unified Information System in the field of procurement, and the parsed data was preprocessed for use in machine learning models.

    Keywords: information system, data analysis, government contract, data parsing, machine learning

  • Computer modeling of the number of flowing and non-flowing cultures of microorganisms

    The article is devoted to the development of a computer program with the help of which it is possible to simulate the number of flowing and non-flowing cultures of microorganisms for educational purposes. The Mono model is taken as the basic model of biomass growth. The apparatus of ordinary differential equations is used for the mathematical description of cell populations. As a result, the structure and functionality of the electronic learning module with its subsequent implementation in Python has been developed. As a result, the laboratory work "Modeling of flowing and non-flowing cultures of microorganisms" was developed, in the form of a computer program, performed within the framework of mastering the discipline "Biophysics" and consisting in studying the basic principles and methods of modeling the processes of development of microorganisms in flowing and non-flowing cultures. The developed program is implemented in the educational process.

    Keywords: computer program, cell population, biophysics, microorganisms, computer modeling, Mono model, Python, biomass, flow conditions, non-flow conditions, system of equations

  • Mathematical modeling of the magnetic field near a narrow capillary at various hematocrit values

    When erythrocytes move along a narrow capillary, they take an asymmetric shape and roll along the capillary like a tractor caterpillar (tank - treading motion). The shape of the erythrocyte is approximated by a truncated cylinder and is uniquely determined by the diameter of the erythrocyte in the capillary, the volume and surface area of the erythrocyte. Other input parameters are the speed of the erythrocyte in the capillary, the frequency of rotation of the erythrocyte membrane, the charge of the erythrocyte, and the number of closed trajectories along which the charges move. It is assumed that the negative charges located on the membrane are equal in magnitude and distributed evenly over the membrane and move along closed trajectories together with the membrane. From the last parameters, you can find the number of charges on the erythrocyte membrane. According to the Biot-Savart-Laplace law, mobile charges generate a magnetic field in the surrounding space. Using computer calculations, the distributions of the magnetic field strength were obtained both near a single erythrocyte rolling along a narrow capillary, and near a capillary along which several erythrocytes move, at various values of hematocrit. The dependence of the maximum value of the magnetic field strength near the capillary on the hematocrit is found. In particular, it was shown that at a distance from the capillary equal to 8 capillary diameters, the maximum value of the magnetic field strength increases by a factor of 1.29–1.36 (depending on direction) with increasing hematocrit from 12.27% to 18.25%.

    Keywords: mathematical model, magnetic field, charge, membrane, erythrocyte, capillary, hematocrit

  • The population transport mobility formation features in the cities of the North and the Arctic

    The article is devoted to the peculiarities and problems of the formation of transport mobility of the cities of the North and the Arctic of Russia. The analysis of the state of the issue, the methodology and the results of the study are presented. Data collection was carried out by means of the questionnaire the sample was 1002 people. According to the results of the study, the degree of use of individual passenger cars, public bus transport, bicycle transport, means of individual mobility (scooter, segways, gyro scooter, monowheel) by the population in the cities of the North and the Arctic was determined.The consequences of the impact of restrictions on movement associated with the Covid-19 pandemic on the degree of use of various vehicles have been revealed. It has been found that respondents use personal and public transport to a greater extent to move around the city. Seasonal conditions have almost no effect on the structure of urban mobility. Prerequisites for the growth of the use of personal motor transport have been identified. The results of this study can be used to improve and manage the transport service system in the cities of the North and the Arctic.

    Keywords: urban mobility, public transport, survey, urban transport system

  • Algorithmic support of a chatbot for consulting potential applicants

    The relevance of creating a chatbot for advising applicants, promoting the university brand and raising awareness about the university is considered. The basic principles of the chatbot functioning are determined. Modeling of the sequence of processes using IDEF0 and UML is performed. The article contains a description of the chatbot algorithm. Activity and state diagrams are used to visualize this algorithm. The graphical interpretation of the logic of the interaction of the system elements is performed at the IDEF3 documentation level. A physical model for storing the data necessary for consultation is presented; the purpose of the tables obtained is described. The issues of fuzzy search by keywords are considered. The article describes the error correction process using the n-gram distance metric and the Damerau-Levenshtein metric. The functioning of the chatbot in the consultation mode when searching for keywords with errors in the user's message is demonstrated.

    Keywords: chatbot, dialog system, messenger, natural language processing, fuzzy search, Damerau-Levenstein distance, n-gram

  • Research of the choosing probability the residents transportation methods in the city

    The development of modern cities is inextricably linked with the development of the urban transport system. Research of the choosing probability the residents transportation methods in the city is necessary for the correct decision-making by specialists. The article considers the probability indicator of choosing a method and means of transportation. The analysis takes into account the remoteness of the place of work (study) from the place of residence of a resident of the city. The data are the results of a survey of 1,562 respondents in Tyumen and their mobility. It is assumed that the provision of territories with socio-economic infrastructure affects the mobility structure of the city's population. The more objects of attraction in an urban area, the less likely it is to use personal cars. The research methodology is proposed to be used for making managerial decisions in the field of urban logistics and transport planning.

    Keywords: urban transport system, transportation mode choice, survey, public transport

  • Economic and mathematical model for determining the influence of factors characterizing the specifics of dismantling works on the operating costs and duration of operation of machines and mechanisms

    The authors of the article have developed an economic and mathematical model for determining the influence of factors characterizing the specifics of dismantling works on the operating costs and duration of operation of machines and mechanisms, the scientific novelty of which is that, unlike existing models, it takes into account the normative-parametric method, regression and covariance dependencies, which makes it possible to assess the totality of the influence of factors on operational costs and duration of operation of machines and mechanisms, describe the procedure for calculating the operating costs and duration of operation of machines and mechanisms and generate the amount of investment in the operating costs of machines and mechanisms.

    Keywords: dismantling works, economic and mathematical model, operating costs, machines and mechanisms

  • Algorithm of formation of volumetric model of pathological focus of the retina on the basis of optical coherence tomography scans

    The most informative methods in diagnostics of retinal pathological conditions are ophthalmoscopy, fluorescence angiography (FAG), optical coherence tomography (OCT) and optical coherence tomography with angiography (OCT-angiography, angio-OCT, OCT-A). This paper describes an algorithm of retinal pathologic focus formation based on optical coherence tomography (OCT) scans. The algorithm allows to create a volumetric model of the pathological focus within clinically significant boundaries by separate segmentation of each of the macular cube scans, extraction of the pathological focus point cloud and its reconstruction into a polygonal 3D model. Certain morphometric parameters extracted from such a model are important for better analysis of retinal pathology. This will allow the ophthalmologist to prescribe the appropriate type and amount of treatment to stabilize and improve visual functions.

    Keywords: AMD, OCT, macula, retinal pathology, dot cloud, medicine, computer vision, wet AMD

  • Modeling of Solid-Phase Bonding of Dissimilar Powder Layers in Wedge Hot Compaction

    The bimetallic iron-bronze powder material obtained by wedge hot compaction is considered. A hypothesis is formulated, confirmed by the results of experimental studies, about the determining effect of volumetric deformation of the powder material of the iron base in the process of wedge hot compaction. The concept of an indicator is introduced and a 2D Impulse model of the quality of consolidation of heterogeneous powder layers is constructed from the absolute values of the volumetric deformation of the iron base. As a result of the analysis of the constructed 2D Impulse model for the transition zone of a bimetal obtained by technology including sintering, the absolute value of │0.21│ of the critical volumetric deformation was established, which ensures the transition from satisfactory to good quality of consolidation, taking into account the introduced quality scale. For technology that does not involve sintering, the absolute value of │0.171│ of critical volumetric strain, equal to the parameter "c" of the model, characterizes the transition from unsatisfactory to satisfactory quality of consolidation.

    Keywords: diversification of management, production diversification, financial and economic purposes of a diversification, technological purposes of ensuring flexibility of production

  • Research and features of the mathematical model of the Darye rotor

    In this paper, a mathematical model of a wind generator similar to the Darya rotor has been developed. The fast turbine rotation mode or autorotation mode is considered. Using the averaging method, the value of the steady-state angular velocity of the wind turbine in the autorotation mode is obtained. A set of programs has been written in the matlab computer system and numerical counting results have been obtained. They are compared with analytical estimates. A parametric analysis of the geometric dimensions of the wind turbine was carried out to obtain a given power. The advantages and disadvantages of this design in comparison with other types of wind turbines are shown. As a result of these calculations, it can be concluded that Darye wind turbines will be effective only for obtaining small power and at small sizes. Large devices fail too often and their maintenance is too expensive.Large devices require too expensive maintenance.

    Keywords: wind turbine, autorotation mode, stability, geometric dimensions

  • Overview of modern veterinary diagnostic software

    The article presents an overview of modern veterinary diagnostic software used both in Russia and abroad. The purpose of this study is to formulate the requirements for the diagnostic information system being developed. During the review process, the software, guided by its purpose and functionality, was divided into several groups. The most famous and characteristic examples are presented and described in each group. This review of existing systems made it possible to formulate user requirements more fully and take into account current trends in the field of veterinary medicine accumulated in various information systems when developing the concept of an expert system.

    Keywords: expert system, information system, database, diagnostic software

  • Interaction of metal powder with gas during cooling

    This article discusses the solution to the problem of calculating the processes of crystallization of metal drops in the process of blowing the melt with gas in the production of powders. Calculations of the drop formation process and estimates of the phase transition time and until complete cooling are given depending on the particle size in the range of 50-500 µm with preheating of the gas flow to various temperatures from 0 to 500 degrees C. A technique has been developed for calculating the cooling time of a drop of molten metal in a gas flow during the production of metal powder by the sputtering method, and the ratio of the components of the total drop cooling time has been determined.

    Keywords: metal powder, melt spraying, particle cooling, gas flows, heat transfer, additive technologies, technological process, gas dynamic process