Software tool for evaluation of reliability and survivability of complex technical system based on logical-probabilistic methodology

The paper presents solutions for estimation and analysis of complex system (CS) reliability and survivability indicators based on the logical-probabilistic approach. Modified logical-probabilistic method and software tool for evaluating the reliability and survivability of onboard equipment (OE) of small satellites were developed (SS). The correctness of the suggested method and software tool was shown by computational experiments on some systems of CS SS similar to Belarusian SS, and later compared with the “Arbitr” software complex results.

РАЗРАБОТКА И ИСПОЛЬЗОВАНИЕ ЛОГИЧЕСКОЙ СХЕМЫ ДЛЯ РАСЧЁТА НАДЁЖНОСТИ СИСТЕМ АПК

Проведён анализ моделей процессов, происходящих в сложных системах на объектах АПК. Произведена оценка эффективности и оптимизации сложных систем различного назначения. Обосновано применение в научных исследованиях универсальной имитационной модели, которая может быть адаптирована к любому объекту АПК из указанного класса. Проанализированы различные математические схемы систем автоматического управления и систем массового обслуживания. Предложен подход к составлению логической схемы для оценки надёжности технической системы, на основе которого формируются формулы расчёта вероятности их надёжного функционирования. The analysis of models of processes occurring in complex systems at agricultural facilities is carried out. The efficiency and optimization of complex systems for various purposes are evaluated. The use of a universal simulation model in scientific research, which can be adapted to any object of the agro-industrial complex from the specified class, is justified. Various mathematical schemes of automatic control systems and queuing systems are analyzed. An approach to drawing up a logical scheme for assessing the reliability of a technical system is proposed, on the basis of which formulas for calculating the probability of their reliable functioning are formed.

Functioning of a technical system with an instantly replenished time reserve, taking into account preventive maintenance

В работе рассматривается функционирование технической системы с мгновенно пополняемым резервом времени с учетом профилактики. Приводится описание функционирования такой системы. При использовании аппарата полумарковских исследований производится построение аналитической модели системы с мгновенно пополняемым резервом времени при учете влияния профилактики на ее производительность. При построении полумарковской модели принимается ограничение на количество профилактик за время восстановления рабочего элемента. Описываются полумарковские состояния исследуемой системы, и приводится граф состояний. Определяются времена пребывания в состояниях системы, вероятности переходов и стационарное распределение вложенной цепи Маркова. Для определения функции распределения времени пребывания системы в подмножестве работоспособных состояний с использованием метода траекторий находятся все траектории переходов системы из этого подмножества в подмножество неработоспособных состояний и вероятности их реализации. Определяются времена пребывания системы в найденных траекториях. На основании теоремы полной вероятности определяются функции распределения времен пребывания системы в подмножествах работоспособных и неработоспособных состояний и коэффициент готовности системы. Приводится пример моделирования исследуемой системы. Проводится сравнение полученных результатов с результатами использования теоремы о среднестационарном времени пребывания системы в подмножестве состояний. The work examines the functioning of a technical system with an instantly replenished reserve of time, taking into account prevention. The description of the functioning of such a system is given. When using the apparatus of semi-Markov studies, an analytical model of the system is constructed with an instantly replenished reserve of time, taking into account the effect of prevention on its performance. When constructing a semi-Markov model, a limitation on the number of preventive measures during the restoration of a working element is adopted. The semi-Markov states of the system under study are described, and the state graph is given. The sojourn times in the states of the system, the transition probabilities, and the stationary distribution of the embedded Markov chain are determined. To determine the distribution function of the time spent by the system in a subset of operable states using the trajectory method, all trajectories of the system's transitions from this subset to the subset of inoperable states and the probability of their realization are found. The residence times of the system in the found trajectories are determined. On the basis of the total probability theorem, the distribution functions of the sojourn times of the system in subsets of the healthy and inoperable states and the system availability factor are determined. The modeling example of th system under study is given. The results obtained are compared with the results of using the theorem on the average stationary sojourn time of the system in a subset of states.

System risk assessment based on the probabilistic model “exposure-susceptibility” at the enterprises of storage and processing of vegetable agricultural products

At present, elements of probabilistic safety and risk assessment have been introduced into the design and analysis of complex technical systems, one of the main disadvantages of which is the difficulty due to the selection of initial data in the form of probabilities of initiating events. As a consequence, the use of known methodologies for quantifying risk can lead to either underestimation of threats or unreasonably high security costs. On the example of an enterprise for the storage and processing of vegetable agricultural products, an approach was considered for assessing the risk of a technical system based on the probabilistic model “exposure-susceptibility”.

Framework for Assessing Ethical Aspects of Algorithms and Their Encompassing Socio-Technical System

In the transition to a data-driven society, organizations have introduced data-driven algorithms that often apply artificial intelligence. In this research, an ethical framework was developed to ensure robustness and completeness and to avoid and mitigate potential public uproar. We take a socio-technical perspective, i.e., view the algorithm embedded in an organization with infrastructure, rules, and procedures as one to-be-designed system. The framework consists of five ethical principles: beneficence, non-maleficence, autonomy, justice, and explicability. It can be used during the design for identification of relevant concerns. The framework has been validated by applying it to real-world fraud detection cases: Systeem Risico Indicatie (SyRI) of the Dutch government and the algorithm of the municipality of Amersfoort. The former is a controversial country-wide algorithm that was ultimately prohibited by court. The latter is an algorithm in development. In both cases, it proved effective in identifying all ethical risks. For SyRI, all concerns found in the media were also identified by the framework, mainly focused on transparency of the entire socio-technical system. For the municipality of Amersfoort, the framework highlighted risks regarding the amount of sensitive data and communication to and with the public, presenting a more thorough overview compared to the risks the media raised.

DIGITAL Analysis in Digital Transformation

Aim. The presented study aims to develop an approach to selecting a process in the organization’s activities or a section of a separate process, the digital transformation of which will produce the greatest effect.Tasks. The authors determine a general approach to choosing where to apply digital technologies in an organization or in the transformed process to the greatest effect; develop criteria for choosing where to apply a transformational solution during digital transformation; create a conceptual framework for process analysis during digital transformation; ensure the reproducibility and efficiency of digital transformation regardless of the level of competence of the responsible manager.Methods. The methodological basis of this article includes studies on digital transformation, theoretical and practical materials regarding the application of transformational solutions during its implementation, and practical cases of digital transformation. The applied methods make it possible to identify patterns and form a conceptual understanding of the approach to analyzing the efficient use of digital technologies. When searching for a conceptual solution to the problem of finding a place to apply digital technologies, the authors use their developments in the field of digital transformation.Results. The DIGITAL analysis method developed by the authors contains a conceptual understanding of criteria for choosing where to apply a transformational solution during digital transformation within the specific transformed process, making it possible to digitally transform any process or organization as a whole until they reach the level of digital maturity corresponding to an autonomous technical system. The developed method of DIGITAL analysis increases the efficiency of digital transformation and does not require significant experience in its implementation. The novelty of DIGITAL analysis is that it makes it possible to turn digital transformation into a formalized process instead of the usual application of well-known digital transformation cases.Conclusions. The DIGITAL analysis method not only increases the efficiency of digital transformation, but also provides an opportunity to effectively choose where to apply a transformational solution. The developed method of DIGITAL analysis can be used independently or as a component of a comprehensive methodology for conducting digital transformation. The use of DIGITAL analysis is not tied to a particular industry or process under consideration.

Regional reclamation landscape technical systems: current status and rational use

The problems of the current state of possibilities of reconstruction and rational use of regional reclamation landscape technical systems have been considered. It has been noted that for studying the process of their formation and modern functioning GIS-method (GIS-packages SAS.Planet.Release and GoogleEarthPro) were used in addition to field landscape research. The meaning of the concept of “reclamation landscape technical system” as a structure in which interconnected hydraulic structures and water bodies that are necessary to ensure and maintain the optimal operation mode of the reclamation landscape complex has been clarified. The main types of reclamation such as hydraulic, cultural, chemical, agrotechnical and agroforestrytechnical have been partially discribed. The essence of the concept of “hydraulic reclamation” as a set of measures aimed at improving the water- air (waterlogging and dehydration) regime of soils has been considered more detailed. The expediency of resumption of reclamation measures in the territory of Ukraine has been confirmed, as 2/3 of its area is in conditions of unfavorable water regime. This study is focused on the analysis of drainage and humidification systems as the most effective in ensuring the regulation of excessive moisture or its deficit. It has been shown that the peak of reclamation works and construction of reclamation landscape technical systems was observed 1950–1965. The largest irrigation, drainage, polder and drainage-humidification systems in Ukraine have been discribed. It has been found that the decline of reclamation systems began in 1991 and was characterized by a reduction in the area of irrigated and drained lands and the deterioration of their ecological condition. Emphasis has been placed on the study of regional drainage and humidification systems and three stages of their development in Ukraine have been identified. Possible measures for the rational use of reclamation systems on the example of the Trubizh regional drainage and humidification landscape technical system have been proposed. It has been noted that the development of regional plans for the rational use of this system should be based on the analysis of the history of economic development of the Trubizh river basin and taking into account the specifics of the landscape structure of the canal-floodplain type. Reconstruction of the reclamation system has been recommended to conduct in two stages: the first one is based on the modernization of hydraulic structures and the main canal, the second one is based on the internal and landscape structure of the system. The feasibility of partial restructuring of the open network for closed drainage and the creation of temporary drainage channels has been confirmed, which will allow more rational use of resources of the Trubizh reclamation landscape technical system.