Modeling and visualizing of the formation of a snub dodecahedron in the AutoCAD system

The article is devoted to modeling and visualization of the formation of flat-nosed (snub-nosed) dodecahedron (snub dodecahedron). The purpose of the research is to model the snub dodecahedron (flat-nosed dodecahedron) and visualize the process of its formation. The formation of the faces of the flat-nosed dodecahedron consists in the truncation of the edges and vertices of the Platonic dodecahedron with the subsequent rotation of the new faces around their centers. The values of the truncation of the dodecahedron edges, the angle of rotation of the faces and the length of the edge of the flat-nosed dodecahedron are the parameters of three equations composed as the distances between the vertices of triangles located between the faces of the snub dodecahedron. The solution of these equations was carried out by the method of successive approximations. The results of the calculations were used to create an electronic model of the flat-nosed dodecahedron and visualize its formation. The task was generally achieved in the AutoCAD system using programs in the AutoLISP language. Software has been created for calculating the parameters of modeling a snub dodecahedron and visualizing its formation.

STUDY OF SYSTEMS WITH ELECTRODYNAMIC AND ELASTIC CONNECTIONS UNDER HARMONIC EXCITATION

Purpose of the study is to analyze the operation of a mechanical system with the introduction of electrodynamic and elastic components into it to ensure that the operating modes of the latter go beyond the resonance modes. The tasks of the research involve the synthesis of the mathematical apparatus with the subsequent formation and analysis of the amplitude-frequency characteristics of the specified system. Research methods. The methodological basis of the work is the generalization and analysis of the known scientific results of the dynamics of systems in resonance modes and the use of a systematic approach. The analytical method and comparative analysis were used to form a scientific problem, form a goal and formulate research objectives. When creating empirical models, the main provisions of the dynamics of systems were used. The results of the study. Considering that the dynamic properties of the system depend on the presence or absence of an elastic connection of the transmission line, a combined system was subjected to research. Since it is impossible to obtain an exact analytical solution of the obtained system of nonlinear differential equations, the solution was carried out on an electronic model with harmonic excitation. Based on the results of studies on an electronic model, using the MatLab computer modeling system, it is difficult to establish the influence of the ratio of various parameters, with their possible variations in a large range, on the behavior of the system itself, since a question posed in this way will require a significant amount of computer time. Therefore, a study of the system with harmonious excitation in its linearized form was carried out. Conclusions. A mathematical model of the functioning of a system with electrodynamic and elastic coupling under harmonious excitation has been formed. On the basis of the research carried out, the amplitude-frequency characteristic of the system was built, with the help of which the correspondence of the results of the solution of the electronic (reference), built on the basis of MatLab, and the analytical models was established.

Implementation of the electronic model of the thematic and typological acquisition plan in the scientific library

Automation of library processes is an important topic in modern conditions of digitalization and transition of human activities to the latest computer technologies. Acquisition of literature to library collections forms the document base for the subsequent work of the library, so this process needs continuous improvement and optimization of its constituent operations. The article is devoted to the application of computer technologies in the preparation and use of the scientific library thematic-typological plan of acquisition as the scientific base of building collections. The object of the article is to present the experience of creating and using the electronic model of the Thematic and Typological Acquisition Plan in the scientific library, to define the perspectives of implementing the data base for information and library servicing UB RAS users.The article presents the results of content analysis of subject headings and indices of the State Rubricator of Scientific and Technical Information for bibliographic descriptions of Russian journals received in 2015–2017, in the Consolidated electronic catalog of periodicals of the Central Scientific Library of the Ural Branch of the Russian Academy of Sciences; of books, published by the institutes of the Ural Branch of the Russian Academy of Sciences in 2015–2017, according to the Electronic catalog of Russian books and continuing publications of the Central Scientific Library of the Ural Branch of the Russian Academy of Sciences; of publications (published in 2015–2019) of the institutes of the Ural Branch of the Russian Academy of Sciences, included in the database of the Russian Science Citation Index on the portal «eLIBRARY.ru» – are presented in the article. It also describes the stages of creation, analyzes the characteristics and capabilities of the database «Thematic-typological acquisition plan» of the Central Scientific Library of the Urals Branch of the Russian Academy of Sciences.

Satellite mega-constellations create risks in Low Earth Orbit, the atmosphere and on Earth

The rapid development of mega-constellations risks multiple tragedies of the commons, including tragedies to ground-based astronomy, Earth orbit, and Earth’s upper atmosphere. Moreover, the connections between the Earth and space environments are inadequately taken into account by the adoption of a consumer electronic model applied to space assets. For example, we point out that satellite re-entries from the Starlink mega-constellation alone could deposit more aluminum into Earth’s upper atmosphere than what is done through meteoroids; they could thus become the dominant source of high-altitude alumina. Using simple models, we also show that untracked debris will lead to potentially dangerous on-orbit collisions on a regular basis due to the large number of satellites within mega-constellation orbital shells. The total cross-section of satellites in these constellations also greatly increases the risk of impacts due to meteoroids. De facto orbit occupation by single actors, inadequate regulatory frameworks, and the possibility of free-riding exacerbate these risks. International cooperation is urgently needed, along with a regulatory system that takes into account the effects of tens of thousands of satellites.

Approaches to the implementation of hydraulic electronic models of centralized water supply systems

Introduction. The analysis of the Russian normative and methodological documents, as well as research articles, has identified gaps in the development and practical implementation of hydraulic electronic models of existing water supply systems. The user guide of the software products, used to design these models, merely demonstrates the capabilities of software modules and misses the outcome of their application in certain cases. Decree No. 782 issued by the RF Government on September 5, 2013, being the document that regulates the development of electronic models of water supply systems, lists the requirements applied to software. The document, titled Construction regulations SP 31.13330.2012, has the requirements applicable to the hydraulic analysis of water supply system designs. This suggests that the Russian regulatory environment has no document that contains the basic requirements governing the development and detailing of hydraulic electronic models of water supply systems. This is an essential problem of urban utility networks, since the hydraulic electronic model is the basis for any further actions in strict accordance with which a development plan of a centralized urban water supply system is designed. Materials and methods. The article has a scientific review of the problem of design of electronic hydraulic models of centralized water supply systems and basic principles and approaches to electronic model generation. Results. The co-authors provide a detailed description of a methodology used to develop a model of urban water supply systems as well as the requirements set by foreign standards. Conclusions. Model development and calibration is structured in the article. This information is needed to adjust the characteristics of the designed model to a water supply system in operation.

SYNTHESIS OF THERMAL DIAGNOSTIC EXPERT COMPONENTS WITH AN ARTIFICIAL NEURON

The article notes the growing popularity of digital programmable technology in diagnostic monitoring systems of electromechanical equipment (EME) for various purposes due to the ability to monitor the technical condition of operating devices in real time. The main reasons that restrain the use of DMS with artificial neural networks in the municipal sphere are considered. It has been noted the directions of improvement of popular means of thermal parameters monitoring and hardware solutions to increase the initial data validity used in the possible EMO fault identification. The purpose of this work was to study and develop components for the formation of initial information, including artificial neurons, which make it possible to increase the reliability of possible fault identification accompanied by heating of individual parts of the operated electromechanical equipment. Based on the adopted algorithm for approximating the initial data arrays, the priority of using the logistic function for modeling the rate of temperature change in the EME was justified. It have been proposed the electronic model structure of an artificial neuron (AN) and an algorithm for generating information output signal, depending on the rate of change of a controlled parameter at a technological object. It have been presented the electronic modeling results in the Simulink environment and the physical implementation of the AN electronic model, which confirmed the suitability of the proposed device in the diagnostic thermal expert of the EME technical condition during its operation in real time. Electronic experiments with AN made it possible to obtain a calibration characteristic for a practical assessment of the tendency for the development of non-standardized thermal events that may cause possible faults in certain parts of the equipment. It have been considered possible options for using AN in local thermal diagnostic tools for the analysis and assessment of events indicating the feasibility of performing unscheduled maintenance or preceding possible and unknown electromechanical equipment faults. It has been presented the results of experiments and simulation of thermal processes, confirming the expandability of the functional diagnostic devices properties with neural network systems, which popularity is constantly growing.

MATHEMATICAL MODEL OF THE RADIATING APERTURE OF HEADLIGHTS CONSISTING OF SEGMENT-PARABOLIC ANTENNAS

Решение задачи связи в Арктике, а также в тундре, в тайге, в лесу, в море, на полях возможно только с использованием мобильных систем спутниковой связи. ФГУП «Космическая связь» (г. Москва) располагает группировкой спутников, которая постоянно расширяется. Для надежной связи в Арктике и в северных широтах, помимо геостационарных спутников, запущены спутники, движущиеся по высокоорбитальным траекториям. Для переключения со спутника на спутник, входящий в зону видимости абонента, необходимо использовать антенные решетки. Проблема заключается в том, что в настоящее время отсутствуют мобильные терминалы высокоскоростной спутниковой связи, а стоимость зарубежных аналогов препятствует широкому их использованию (достигает 50 тысяч долларов). Обычно радиолокационная связь (РЛС) с фазированной антенной решеткой используется для наблюдения за тысячами угловых точек, для отслеживания сотни целей. Такие требования могут быть выполнены только путем сканирования луча в пространстве в течение микросекунды. Ясно, что необходимо электронное управление лучом, поскольку механически вращать антенну не представляется возможным. Лишь некоторая часть вышеуказанных проблем будет затрагиваться в этой статье, ниже будут представлены электронная модель антенной решетки и её математическая модель The solution of the communication problem in the Arctic, as well as in the tundra, in the taiga, in the forest, in the sea, in the fields is possible only with the use of mobile satellite communication systems. FSUE "Space Communications" (Moscow) has a constantly expanding group of satellites. For reliable communication in the Arctic and Northern latitudes, in addition to geostationary satellites, satellites moving along high-orbit trajectories were launched. To switch from one satellite to the other included in the subscriber's visibility area, it is necessary to use antenna arrays. The problem is that currently there are no mobile terminals for high-speed satellite communication, and the cost of foreign analogues prevents their widespread use (up to 50 thousand dollars). Typically, a phased array radar is used to track thousands of corner points to track hundreds of targets. Such requirements can only be met by scanning the beam in space for a microsecond. It is clear, that electronic beam control is necessary since it is not possible to mechanically rotate the antenna. Only some of the above problems will be touched upon in this article. An electronic model of the antenna array and its mathematical model is presented