Many governmental agencies and private companies of different countries are now rushing into space around Earth in the hope to provide smart communication, industrial, security and defense solutions. This often involves massive launches of small cheap satellites which are also contributing to the growth of space debris. The current paper discusses how the developed high-level system philosophy and model can effectively organize distributed space-based systems on different stages of their development and growth. The briefed Spatial Grasp Technology, based on parallel pattern-matching of distributed environments with high-level recursive mobile code, can effectively provide any networking protocols and important applications of large satellite constellations, especially those in low Earth orbits. The article gives some examples of technology-based solutions for establishing basic communications between satellites, starting from their initial, often chaotic, launches and distributing and collecting data in the growing constellations with even unstable and rapidly changing connections between satellites. It describes how to organize and register networking topologies in case of predictable distances between satellites, and how the fixed networking structures can help in solving complex problems. The latter includes those related to the new Space Development Agency’s multiple-satellite defense-oriented architecture and allows for effective integration of its continuous Earth custody observation and cooperative missile tracking and elimination layers, based on self-spreading mobile intelligence. Earlier versions of the technology, described in many papers, six books including, were prototyped and used in different countries, with the current one quickly implementable too, even in university-based environments. Figs.: 9. Refs.: 38 titles.
The article is focused on the principles of situational management, situational centers in management systems, the legal basis of the creation and functioning of the system of public authorities’ situational centers. The paper addresses the following issues of the theory of thesecurity and defense sectorsituational management construction (SDC): foundations, means and technologies of situational management, the necessity to use situational centers (SC) in management, the concept of the creation of a SCs network, features typical for the SC of public authorities of the security and defense sector. The practice of situational management creation is shown on the example of the Basic Modeling Complex (BMC). The paper describes therequirements and decisions regarding the organizational and functional structures that were taken into account when creating the complex. The features of the creation of the general structure of the BMC and the composition of the set of means for its automation have been analyzed, and «Assessment of risks and threats to the security and defense sector» and «Support for the work and interaction of officials of situational centers in decision-making»models have been described. The structure and mathematical methods used for the operation of models have been revealed. To sum up, the use of methods and systems of situational management, which combine technologies to support decision-making, storage, processing, concentrated display and presentation of information, radically changes the principles of analysis, discussion and solution of large-scale and complex management problems. SCs of state authorities of Ukraine, thecreation of which has recently intensified, should be integrated into a united network of theSCs of the SDS. The requirements for the integration, including requirements at the level of information exchange, must be taken into account. Іл.: 8. Бібліогр.: 9 назв.
The paper compares three methods of coding nominal variables in regression analysis: coding of each level as a separate variable, coding with binary code, numbering of factor levels. Although these methods have existed for a long time and even have a theoretical justification (except for encoding with binary code), there were no recommendations and comparisons for their practical application. The features of the application of each method and the existing limitations are analyzed. In the article, there are considered two examples that provide a detailed comparison of these three methods. Comparative analysis has been carried out in the following areas: the presence of restrictions in use; statistical properties of plans; labour intensity and difficulty of obtaining mathematical models and the final result of their building; convenience of semantic analysis and use. Additionally, there have been made comparisons with models based on Chebyshev orthogonal polynomials. It has been established that different methods of coding nominal variables, when used correctly, lead to regression models that are approximately identical in their properties. Moreover, the method of encoding each level as a separate variable is possible only if there are experiments in which there is no nominal variable as an influence effect. The binary coding method is inconvenient to use with a large number of levels of variation of the nominal variable and inconvenient to analyze. When coding by level numbering, it is necessary that the average response values, according to the dispersion diagram of this factor, are sorted by value in accordance with the assigned numbers. With this encoding method, a natural number of factors is preserved. Sharply distinguishable best results are achieved with this coding method using Chebyshev orthogonal polynomials. The highest accuracy and uniformity of approximation are ensured. Таbl.: 10. Figs.: 4. Refs.: 13 titles.
A stage when an average value began to be considered as a central term of a continuous proportion is considered to be the beginning of the development of the «average value» concept. However, this concept, as the central value of the progression, does not make it possible to derive it in relation to a sequence of n terms, regardless of the order in which they follow each other. For this purpose, it is necessary to resort to a formal generalization of average values which predetermined the transition from continuous proportions to progressions - arithmetic, geometric and harmonic. Currently, a statistical value is given to the average value through its connection to economic categories. In the mathematical theory of average values, there are distinguished two types of them – average values themselves and arithmetic average values. At the same time, each type of average values can act either in the form of asimple or weighted average where the correct choice of the form of the average follows from the material nature of the object of study. Simple average formulas are used in cases where the individual values of the averaged feature do not repeat. If the frequency of repetition of individual values of a feature is present in the calculation formulas of averages, then in this case the formulas of simple averages are called as formulas of weighted averages. With the respect to it, the paper proposes an approach to the description of average socio-economic indicators, using the example of the indicator «Average market value of a square meter of housing» in the real estate market in a hypothetical region by averaging prices based on their weighted average assessment in a particular area. Within the framework of this approach, the distribution function of the weights of housing costs is identified as a self-similar solution (automodel) of a partial differential equation with initial and boundary conditions.Таbl.: 2. Figs.: 4. Refs.: 13 titles.
Diagnosing the equipment of complex technological installations is a guarantee of their safe and efficient performance. Theaims of the diagnostic systems creation are the following: timely prevention of possible failures and malfunctions of systems and equipment; the necessityof having a complete and holistic picture of the actual technical condition of the operating systems and equipment; highaccuracy forecastingof the residual life of the equipment; minimization of cost and increase of efficiency of works on technical conditions monitoring, maintenance, repairs and management of resource characteristics of systems and equipment; continuous improvement, based on objective performance data, actual characteristics of safety, reliability and operational readiness. To such complex technological installations there belongs the equipment of hot rolling shops, for example, mechanical equipment of the mill, electric drive with control systems, devices and control systems for hydraulics, lubrication and cooling management, ventilation stations, pumping stations; switchgear cells (high voltage switches), complex of APCS of heavy-plate mills rolling technical means.The article considers some methods of operational control of the technical condition of the heavy-plate rolling millsequipment. The factors that influence the efficiency of the diagnostic algorithms used in the APCS, in particular, the organization of collection and processing of statistical data on the possibilities of malfunctions and the costs of their search and elimination are determined in the paper. Formalization of methods for construction and description of mathematical models of the object of diagnostics is performed. Utilization of the subsystem of control and diagnostics in the APCS of modern rolling mills provides a significant improvement in thereliability of theAPCS of heavy-plate mills rolling, as well as some economic effects. Refs.: 8 titles.
Mathematical machines and systems. 2021. N4. Р.70–77. Analysis of the dynamics of neutron flux density (NFD) from fuel-containing masses (FCM) in the «Shelter» Object shows the presence of values that exceed the average values for different observation periods. Identification of such values by the criterion of «anomaly / non-anomaly» will allow excluding uninformative events from the array of observations. Or, in the case of the anomaly confirmation, it will allow forming effective actions for decision-making in order to eliminate the consequences of such events. To solve the problem of detecting anomalous measurements, now there is utilized the theory of statistical solutions which is based on the use of parametric methods. The utilization of these methods requires a priori information about the nature of the distribution of the measured process and its parameters. In order to find an effective solution to the problem of detecting and eliminating anomalous measurements, it is necessary to know the statistical characteristics of normal and anomalous components. This paper proposes statistical criteria for estimating anomalies in time series of NFD which have different approaches to the formation of observation intervals, power and reliability of anomaly detection.Depending on the type of distribution of the array of observations, a set of criteria is proposed. These criteria are most expedient to use when checking the anomaly of series levels for the exponential distribution, the Poisson and Weibull distribution. The capacity of the criteria has been evaluated depending on the sample size.The article defines the accuracy of determination of anomalies by criteria with the known values of the mean and dispersion in the studied sample. As the result, it is recommended to use the Grubbs test to study the anomaly of the sample levels with n>700, and the Dixon and Smolyak-Titarenko criteria for the samples with n<50. The utilization of optimal criteria depending on thecharacteristics of the studied samples will increase the mathematical significance of theobtained results and, as a result, will improve the quality of management decisions and nuclear safety on the «Shelter» Object as a whole. Fig.: 1. Refs.: 11 titles.
The paper reviews the methods for identifying an unknown source of pollution by inverse modeling and information systems for air pollution forecasting and analysis. Several different foreign and Ukrainian air pollution forecasting systems, such as the European Union's Nuclear Emergency Response System RODOS, have been developed on the basis of atmospheric transport models. However, the key data that determine the quality of forecasting in such systems are the characteristics of the emission sources. In the case of detection of pollution from an unknown emission source, there should be performed inverse simulation. The use of the RODOS system, as well as other existing forecasting systems for such a task is possible but it requires multiple manual start of calculations of atmospheric transfer models in the reverse mode. Presented in the paper results of the application of inverse modeling methods during radiation incidents of the last decade demonstrate that modern methods of inverse modeling are sufficiently developed to set the task of automating inverse modeling in information systems for air pollution analysis and forecasting. Even though these methods not always can exactly identify the source of emissions due to the lack of measurements and poor conditioning of the inverse atmospheric transport problem, their application always leads to a significant reduction (by an order of magnitude or more) in thesearch for unknown sources compared to the detection of pollutants. At present, in the existing forecasting systemsthe methods of inverse modeling are only partially automated, namely for thecase of known location and unknown emissions of the source of pollution. Therefore, this paper proposes the architecture of the future system for identifying unknown sources of emissions by inverse modeling.Figs.: 4. Refs.: 24 titles.
Control of speed modes on heavy-plate mills is one of the factors that determine the efficiency of the rolling process. The choice of speed controls influences the mill productivity, geometric dimensions of the rolled product (longitudinal thickness variations) and compliance with the set temperature mode which determine the mechanical properties of the rolled product, etc. The article considers the limitations in the choice of speed controls which can be divided into two groups: limitations of the capabilities of rolling engines and technological limitations. The first group is determined by the allowable engine under the conditions of reliable current switching on the collector and the maximum allowable engine speed. Technological limitations of speed controls are considered in the paper as well. The speed of grasp is limited to the maximum under the condition of metal grasp without skew, blows and dynamic torque overloads in spindles and maintenance of constant grasp without slipping, as well as the possibility of prevention of emergencies. Steady (maximum) rolling speed can be limited to the maximum by the conditions of rolling stability and prevention of sticking of metal to the rolls. The rate of metal release from the rolls is usually chosen in the way so that the pause stipulated by the braking of the sheet on the roller conveyor and its subsequent return to the rolling mill would not exceed the operating time of the pressure mechanism. In some cases, the release rate can be determined by other technological operations. The maximum acceleration of the main drive of the horizontal mill is limited by the conditions of slipping of the working roll towards the support roll. The paper also considers rational speed graphs of rolling on heavy-plate mills. They are the most common type of high-speed rolling graphs on heavy-plate mills. The listed above solutions for the control of high-speed rolling modes can be used in thedevelopment of APCS of heavy-plate mills rolling.Таbl.: 2. Refs.: 8 titles.
On the basis of the new data on the assessment of the removal from fires from stocks in the combustible material and the speed of weak grassroots fires spread, the wind rose in the Chernobyl Exclusion Zone and the capabilities of the HotSpot software package, there has been developed a mathematical model of real-time assessment of the consequences of accidents that may occur in the areas of radiation-hazardous objects during fires.The proposed model was verified on the basis of comparison with the data obtained during a large-scale fire in the Chernobyl Exclusion Zone in April 2020, and the maps of the Chernobyl Exclusion Zone’s air and soil contamination with 137Cs and90Sr were made.Using the proposed mathematical model, there has been carried out the analysis of the degree of danger that maycreate radiation-hazardous objects in case of fire directly on the territory of their location. In the paper, there are also considered the examples of the sanitation point(SP)«Rudnia-Veresnia», SP«Rozsokha» and the «Point of vehicle washing near the ChNPP cooling reservoir» in comparison with the current contamination of air and soil around these facilities with radionuclides. The results of the conducted analysis have been used to make a conclusion about the insignificant impact on the environment of the Chernobyl Exclusion Zone compared to the current level of air pollution and the surface of its territory.Estimates of radiation exposure from SP «Rudnia-Veresnia», SP «Rozsokha» and the «Point of vehicle washing near the ChNPP cooling reservoir» to the environment have been obtained with the help of a simplified mathematical model. These data have a significant correlation with the actual data obtained in April 2020 (during a large-scale fire in the Chernobyl Exclusion Zone) in the areas of location of the points of the automated system of radiation condition control, and places of work, temporary and permanent stay of the personnel and the population.Therefore, the created simplified mathematical model can also be used to assess the radiation impact on the environment in the implementation of emergencies of various kinds at other numerous radiation-hazardous facilities of the ChEZ. Tabl.: 8. Figs.: 8. Refs.: 7 titles.
QUALITY, RELIABILITY AND CERTIFICATION OF COMPUTER TECHNIQUE AND SOFTWARE
To ensure high operational reliability of electronic equipment, maintenance and repair, and prolong the service life of the equipment, there is proposed a system which comprises diagnostics and repair tools, sets of spare parts (so-called «ZIP»), including spare parts design to ensure reliability criteria of the system, i.e., sufficiency, composition and the number of spare parts that are expected to ensure the operation of the system with the required reliability. Thepaper proposes to use the method of calculating spare parts on the basis of more adequate models of reliability which leads to more accurate forecasting of the required amount of spare elements and, as a result, to more efficient completeness of the equipment with spare parts. There have been determined the methods of replenishing which are used depending on the purpose of the equipment, the system of its maintenance and repair, the requirements for equipment reliability: whether it is periodic, or continuous, periodic replenishment with emergency deliveries or replenishment by level. To ensure high operational reliability of electronic equipment, maintenance and repair, and prolong the service life of the equipment, a support system is proposed, which includes diagnostic and repair tools, sets of spare parts, etc. Thedesign of spare parts with compliance with the criteria of system operation reliability is considered. The task of requirements to the indicators of sufficiency of spare parts for products with non-renewable spare elements has been determined. The task of requirements to spare parts adequacy indicators for products with renewable spare parts has been distinguished as well. Thearticle also considers an approach to the calculation and some principles of calculation of indicators of spare parts sets sufficiency. Tabl.: 5. Refs.: 4 titles.
