Logical-probabilistic Method Research Articles

A Model of an Automated Electronic Document Management System Operating under Conditions of Probable Compromise of Signature Keys, Based on a Hierarchical Decomposition of Trusted Storage Environments

The results of an analysis of the functioning of the electronic document management system in the context of the development of methods and means of cryptanalysis and an avalanche increase in the number of processed documents are presented. A conceptual model and method for decomposing the storage subsystem into contours of operational and long-term storage of electronic documents are proposed. A mathematical model of hierarchical control of the integrity of electronic documents is presented, which takes into account the integrative properties of electronic documents, as well as requirements for storage periods and information security. The methodology and results of assessing the advantages of the developed technical solution based on the logical-probabilistic method are presented.

Application of logical methods in expert analysis of automotive engine failures in operation

Problem. It is known that the causes of failures in automotive engines can be determined based on existing experience in studying various engine malfunctions. However, an analysis of known methods for determining the causes of car engine failures shows that their use in practice, including in diagnosing the technical condition of engines, requires a lot of work and highly qualified personnel that in many cases is practically ineffective. Logical-probabilistic methods are also known, including those based on fault tree analysis. However, it is not possible to use such models and methods in searching for the c auses of engine failure. Goal. The purpose of the study is to create a methodology for determining the causes of faults and failures in engine operation, which can be applied with help of a logical way and applicable not only by the specialists with expert level, but also the wide qualification. Methodology. The solution to this problem was found in several stages. Initially, by structuring the symptoms, a fault tree was constructed that logically describes the cause-and-effect relationships between the failure event and the original damage that caused it. Data from expert studies of engine failures were used to construct the graph. This was done for each of the engine failure types selected for analysis. Next, a modified (inverted) fault tree was developed for a finite number of selected failure types. Results. Obtained logical graphs allow you to perform a simple logical analysis in the opposite direction from the generally accepted one, from the event of a system failure to the basic damage events that cause it. After obtaining logical graphs for each type of failure, a modified engine fault tree can be compiled, common to the considered types of failures. Originality. The proposed method was widely used previously in the study of reliability of various technical systems, however, this method for the first time has been proposed to determine the causes of engine failures. Practical value. As a result of using the proposed methodology in practice, it it became possible to determine the causes of failure in the engine with enough reliability for practice and minimal time expenditure.

Methods for assessing the reliability of in-shop power supply

Research activities in the field of development of electrical power and electrical equipment include the development of new approaches to assessing the reliability indicators of electrical equipment elements and in-house power supply systems in general. The study has examined methods for assessing the reliability of electrical equipment in intra-shop power supply systems using the example of a workshop network section, including its main elements: power transformer, low-voltage cable lines, distribution points, circuit breakers, magnetic starters, contactors, switches. The reliability parameters of the circuit are calculated relative to the distribution cabinet of the power (DCp) and the distribution point of the power (DPp); regarding each connection of DCp and DPp. The methods under consideration are recommended to be used to clarify the frequency and timing of maintenance and repairs of electrical equipment of the in-shop power supply system, as well as to analyze the reliability of operation and identify the least reliable sections of network diagrams. The presented calculation using the logical-probabilistic method by constructing a fault tree is advisable to use to estimate the frequency of power loss of DCp and DPp, as well as individual connections. For the studied circuits, graphical dependences of the probability of failure-free operation of electrical equipment and the occurrence of a failure over time have been constructed.

Evaluation of the effectiveness of sliding redundancy of radioelectronic facilities

Objectives. The increased reliability of radioelectronic facilities can be achieved by the application of structural and load redundancy. Structural redundancy is achieved taking into account multiplicity of redundancy and the intensity of failures of elements of radioelectronic facilities, while load redundancy involves an easing of electrical, thermal, and mechanical operating modes of the elements. The choice of a redundancy method is determined according to reliability indicator requirements, which may often be contradictory. Therefore, the problem of how to effectively combine structural redundancy and load redundancy methods is very topical. In long-life radioelectronic facilities, for example, in satellite communication repeater systems, sliding redundancy is applied when limiting mass-dimensional parameters and consequently consumed energy. The aim of the work is to evaluate the efficiency of sliding redundancy according to various reliability indicators when altering redundancy multiplicity, reserve operating mode, element failure intensity, and switching device type.Methods. To describe the structure of a complex sliding redundancy system, a logical-probabilistic method is used, in which the dependence of the system reliability indicators on the reliability indicators of the elements is formulated as a logical function of operability. Graph-analytical methods are used to compare different variants of reliability logic schemes.Results. Mathematical models have been obtained to evaluate the effectiveness of sliding reservation. A comparative analysis of the efficiency of sliding redundancy with a loaded and unloaded reserve was carried out in terms failure-free operation probability, as well as gamma-percentage resource, failure rate when changing the fractional multiplicity of the redundancy, and element failure rate. The influence of the reliability of the switching device on the efficiency of the sliding redundancy is considered.Conclusions. Practical recommendations on the selection of the redundancy mode are presented according to different reliability indices and constructed mathematical models of the sliding redundancy efficiency coefficients. The correlation between the reliability indices of elements and the switching device whose reliability can be discounted, is determined. To increase the efficiency of sliding redundancy of radioelectronic facilities, it is necessary to combine multiplicity of redundancy and the operating mode of the reserve with approaches aimed at reducing the intensity of failure of elements.

Имитационные модели оценки опасности возникновения подземных аварий в угольных шахтах

The article is related to the safety issues of the coal mines considering not only the standard conditions of their operation, but also the influence of external effects, personnel errors during mining operations and operation of controls and automation. The relationship between the causes of accidents and sources of hazards is shown. The analysis of mine safety research methods was carried out, which allow to identify the most dangerous causes and conditions of the underground accidents to one degree or another. It is shown that at the mining sites, despite the extremely small, but non-zero probability, accidents still occur due to the probability densities of rare dangerous situations leading to severe consequences. The expediency of logical-probabilistic methods for modeling scenarios of possible accidents, which are interpreted by the cause-and-effect diagrams of the occurrence of a chain of incidents, is asserted. Based on the normalization of the frequencies of occurrence of emergency situations in coal mining, a rationale is given for the transition from the weights of various initiating conditions to their contributions to emergency situations. Simulation models of decision-making for operational substantive analysis of emergency situations were developed, including an assessment of the weights and contributions of mining and geological, mining and technical factors, and personnel errors to the risk of methane explosion occurrence, fires and gasification of workings in case of violations in the degassing systems. It is shown that the existing hazards must be able to measure, i.e. have numerical scales. These hazardrs can be assessed based on the construction of hazard trees. Using them, as well as assessments of emergency changes in the state of the technosphere of coal mines, which are based on the analysis of cause-and-effect relationships of hazard sources, simulation models of the hazard of underground accidents were formed and implemented. These models can be considered as functional models of any emergency situation, allowing to obtain analytical estimates of variations in emergency situations by their weights and contributions to the hazard of emergency situations.

ПОВЫШЕНИЕ ЭНЕРГОЭФФЕКТИВНОСТИ И НАДЕЖНОСТИ ГОРНЫХ ПРЕДПРИЯТИЙ НА ОСНОВЕ АНАЛИЗА ГРАФИКОВ ЭЛЕКТРИЧЕСКИХ НАГРУЗОК

This article presents the results of calculation and analysis of indicators of graphs of electrical loads, energy efficiency and evaluation of reliability indicators of power supply systems of the scheme on the example of mining enterprises. The expediency of substantiating the preliminary analysis of electrical load profiles with the subsequent use of a general logical-probabilistic method for calculating the reliability of power supply systems is substantiated. А comparative analysis of the calculation of reliability indicators (availability coefficient, average operating time, average recovery time, probability of failure-free operation) for individual consumers in case of failure of several elements is presented. The influence of the reliability of individual elements on the reliability of the system as a whole is evaluated. А comprehensive approach is proposed to solve the problem of assessing energy efficiency indicators (specific electricity consumption for open-pit mining, specific electricity consumption for processing plants, the number of hours of power use) and reliability indicators of power supply systems for mining enterprises by applying a logical-probabilistic calculation method under the condition of limited power supply. Recommendations for improving energy efficiency and analyzing the reliability of power supply to industrial enterprises are given.

Application of artificial intelligence methods in estimation the risk of transporting a patient by road

The paper proposes an original logical-probabilistic method for calculation of the risk of medical evacuation of tough patients by road transport. A comprehensive estimation of road conditions and risk factors for transporting an intensive care patient, as well as the calculation of a formal quantitative measure of the risk of transportation by the method of Bayesian inference have been considered. An effective instrument for estimating transportation risks for medical decisions support has been developed.

Improving a no-failure operation of a PV systems with grid inverters for agricultural regions

The growing interest to the use of power generating complexes based on renewable energy sources has been witnessed recently. It necessitates the need to improve the no-failure operation of such complexes. The highest failure rate is typical for the string inverter in grid-connected PV systems. The failure of the string inverter induces supply termination of electrical energy to the grid. The paper explores an approach to improve the no-failure operation of the process of electrical energy distribution by a PV system to the grid driven by the use of micro inverters. The authors used the logical-probabilistic method to assess the no-failure operation of the PV system. Thus, the authors obtained the expressions to calculate the probability of failure for PV systems, enclosing a string inverter, and micro inverters.

Bayesian Approach for Numerical Calculation of the Risk of Medical Evacuation by Vehicles

An original logical-probabilistic method for calculating the risk of critical patients’ medical evacuation by vehicles is proposed. A comprehensive estimation of road conditions and risk factors for transporting an intensive care patient as well as the calculation of a formal quantitative measure of transportation risk by the Bayesian inference method is considered. An effective instrument for estimating transportation risks for management decision making is developed.

Development of a comprehensive system for assessing the reliability of thermal power equipment

The article reveals the necessity of monitoring the reliability of the electric power system as a complex technical system. Based on the consideration of the main regulatory documents, governing the assessment of the reliability of thermal power equipment and electrical networks, the article indicates the imperfections of the available methods of reliability assessment. A proposed comprehensive reliability assessment system allows a detailed assessment of the reliability of a complex system. The reliability of the power unit of the thermal power plant (TPP) was estimated by the logical-probabilistic method using the domestic software package. The existing problems of forecasting reliability indicators at various technical impacts are considered to obtain reliable calculation results.

MULTIAGENT APPROACH TO COMPUTER MANAGEMENT IN A HETEROGENEOUS DISTRIBUTED COMPUTER ENVIRONMENT

The reliability of modern computing control systems in a heterogeneous distributed computing environment, along with efficiency, survivability, security, control efficiency, is an important component of their quality. Increasingly, these systems fall into the category of "critical", have an absolute impact on the activities of organizations and enterprises within which they operate. The loss of such systems, even for a short time, leads to serious problems related to loss of income, unforeseen costs, downtime of production and personnel, loss of time, and sometimes man-made disasters. As you know, the greatest impact on the reliability of control systems has the reliability and fault tolerance of a set of software and hardware. Therefore, solving problems related to improving the reliability of the software part of the systems is the most urgent task. Currently, significant results have been obtained in the field of evaluation and forecasting of reliability indicators of elements and typical software packages at the stage of their design; a large number of methods known to algorithms and programs are known; a number of normative documents on project reliability assessment have been developed. However, the task of real-time reliability assessment, when accurate and operational accounting of a number of factors is required, has not been sufficiently solved. To solve the problem of multi-agent approach to computing control in a heterogeneous distributed computing environment used methods of systems analysis, set theory - to develop models of task distribution, models of tasks and computing resources, general systems theory - to study and develop methods of task distribution, logic-theory theory. for modeling computational processes. The article considers a multi-agent approach to computing control in a heterogeneous distributed computing environment. The algorithm is based on the use of economic mechanisms to regulate the supply and demand of resources in the computing environment. The architecture of the multi-agent approach and the functions of the agents are described. Particular attention is paid to calculating the reliability of the task plan based on the logical-probabilistic method.

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.

APPLICATION OF SOME MODELS OF POWER SUPPLY SYSTEMS WITH AN EXAMPLE OF TAKING INTO ACCOUNT THEIR RELIABILITY FOR INDUSTRIAL ENTERPRISES IN PRACTICE

The publication presents the most common and promising models and schemes for replacing the power supply system of industrial enterprises, and an example of their use in practice for power supply to sewage treatment plants of a chemical enterprise. Various types of models are considered (in tabular form, in the form of an electrical replacement circuit or in the form of a finite-state machine), as well as a logical-probabilistic approach to the representation of the power supply system. The use of automation systems in power supply systems of industrial enterprises can reduce the total number of accidents, prevent their development, reduce the time of disconnections of electrical installations and downtime of mechanisms, and also allows to transfer to work without constant maintenance a significant number of electrical installations of substations, which, in turn, leads to a reduction in the number of service personnel, increase labor productivity and reduce maintenance costs. One of the main tasks on the way to automating the power supply system of enterprises is to present it in the form of a model. The list of replacement models and schemes that can be used to represent the power supply system of enterprises is quite large, and choosing the appropriate model, for that best meets the requirements of the final goal is quite a complex scientific task. The purpose of this article is to analyze the most common and promising models and schemes for replacing the power supply system and provide recommendations on their application in practice for power supply to sewage treatment plants of a chemical enterprise. Presenting the power supply system in the form of a table allows you to simplify and visually perform certification of electrical equipment, identify problem and weak points in the power supply system of industrial enterprises. Such a table proves that a large amount of electrical equipment at lower levels depends on a single electrical device at higher levels. The representation of the power supply system in the form of a three-phase symmetric replacement circuit can be used to calculate short-circuit currents in symmetric and unbalanced modes in the MatLab program and similar. Using the model of the power supply system in the form of a finite-state machine allows you to visually check the reliability of power supply to consumers, simplify the design of the power supply system of an industrial enterprise, select the state of switching devices in the power supply system and take into account the advantages and disadvantages of each state. It is advisable to use the methods discussed in this article to represent the power supply system (in tabular form, in the form of a finite-state machine or a three-phase symmetric replacement scheme) and their further application and use in automated power supply systems of industrial enterprises. The logical-probabilistic method allows us to consider the issue of power supply reliability based on the theory of logical algebra.

Математическое моделирование безотказности гибридной микроэлектростанции на основе возобновляемых источников энергии

In the conditions of regions with relatively low solar and wind potentials, interruptions in power supply to consumers powered by micro-power plants based on renewable energy sources may be due to a decrease in the power of wind power plants, photovoltaic modules with insufficient wind speed and insolation, respectively, to provide power to consumers. A study of the reliability of a system including a wind power plant, photovoltaic modules, a hybrid charge controller, an energy storage device and an inverter was carried out using a logical-probabilistic method. As part of the study, an analysis was made of the structure of the power supply system and its modes of operation in the event of various events: failure of system elements, replacement of failed elements, diagnostics of elements, decrease in the power of the wind power plant and photovoltaic modules. Combinations of events leading to a power failure of consumers connected to a hybrid micro-power plant have been determined. A fault tree was built for the hybrid micro-power plant. Expressions are obtained for calculating the probability of short-term, long-term power supply interruptions, the probability of power supply interruptions occurring when off-design insolation and wind speed occur. Mathematical modeling of the reliability of the hybrid micro-power plant for the conditions of the central part of the Republic of Mari El has been carried out. It has been determined that the probability of a system failure is determined mainly by the probability of long power outages. In this case, the reliability indicators of the system as a whole are largely determined by the values of the reliability indicators of the hybrid controller and inverter. Keywords: YBRID MICRO-POWER PLANT, RENEWABLE ENERGY SOURCES, RELIABILITY, RURAL POWER SUPPLY

Modeling security violation processes in machine learning systems

The widespread use of machine learning, including at critical information infrastructure facilities, entails risks of security threats in the absence of reliable means of protection. The article views the processes in machine learning systems as the ones occurring in information systems susceptible to malicious influences. The results of modeling events leading to a security breach in machine learning systems operating at critical information infrastructure facilities are presented. For modeling, the technology of creating functional models SADT (Structured Analysis and Design Technique) and the IDEF0 (Integration definition for function modeling) methodology were used as a tool for transition from a verbal functional description of the process under study to a description in terms of mathematical representation. In order to study the scenarios of the transition of machine learning systems to a dangerous state and the numerical assessment of the probability of security violation, mathematical modeling of threats was carried out using the logical-probabilistic method. The authors obtained a visual functional model of system security violation in the form of a context diagram of the system and two levels of decomposition. The hazard function of the system is determined and the arithmetic polynomial of the probability function is derived. In further work the described models will allow researchers to develop methods and algorithms for protecting machine learning systems from malicious influences, as well as to apply them in assessing the level of security.

Estimation of the residual resource of several buildings and structures as a single object

In this article, the author raises the problem of assessing the residual resource of an object, which consists of several buildings and structures. Four different approaches to solving this problem are presented. The advantages and disadvantages of these approaches are presented. The areas of their application are indicated. Within the framework of these approaches, one can use the direct enumeration method, the combinatorial method, the algebra of logic, the general logical-probabilistic method. The author has developed two possible options for calculating the residual resource of these objects using the general logical-probabilistic method. It is proposed to develop a Methodology for calculating the residual life of such objects before the survey. The author indicates the main points that must be prescribed in the developed Methodology. An example of calculating an object consisting of five buildings is given. The scheme of functional integrity is constructed according to the general logical-probabilistic method. In the program complex “Arbiter” the static and probabilistic-time calculation of the given scheme is performed. Then the calculation of the object as a whole was carried out according to the “2 of 5” system. As a result, the value of the probability of failure-free operation and the residual resource of the object as a whole is shown.

Modeling of onboard systems operation of small satellites based on general logical-probabilistic method

An approach for simulating the operation of onboard systems of small satellites has been developed. The purpose of the technique is to simulate all possible combinations of malfunctions in the onboard systems of the small satellite, leading to the occurrence of abnormal situations during their operation. As a result of using the technique, a list of emergency situations is created, which is later used to create programs for complex testing of small satellite on-board equipment at the ground testing stage. The use of the technique leads to a reduction in time for the preparation of tests, provides support in making decisions on the management of the small satellites and reduces the response time to emergency situations that arise during operation.

Криптографический рекурсивный контроль целостности метаданных электронных документов. Часть 4. Оценка защищенности

The purpose of the study is to obtain a numerical assessment of the results of the application, previously presented by the authors, of the method of cryptographic recursive 2-D control of the integrity of the metadata of electronic documents. Research methods: logical-probabilistic method I.A. Ryabinin. Research result: a necessary condition for maintaining the integrity of electronic documents processed by automated information systems for electronic document management is to ensure the required level of metadata security. To evaluate the research results, the probability of violation of the integrity of electronic documents (through destructive influences of authorized users on metadata) was chosen as an indicator of efficiency. The presented approach to the construction of logical-probabilistic models for assessing the level of security of metadata of electronic documents allows in practice to obtain numerical values of the probabilities of transition of the systems under consideration to a dangerous state (associated with a violation of the integrity of the metadata of electronic documents), taking into account the structure of such systems and the real conditions of their functioning. The effect of using the developed method, under the conditions of destructive influences of authorized users (insiders), in comparison with the known solutions (using a hash function) of such problems, is 67% under the given assumptions.

Оценка остаточного ресурса нескольких зданий и сооружений как единого объекта

In this article, the authors raises the problem of assessing the residual resource of an object consisting of several buildings and structures. Four different approaches to solving this problem are presented. The advantages and disadvantages of them are considered, and the application areas of these approaches are indicated. Within the framework of these approaches, one can use the direct enumeration method, the combinatorial method, the algebra of logic, and the general logical-probabilistic method. The authors has developed two possible options for calculating the residual resource of these objects using the general logical-probabilistic method. It is proposed to develop a methodology for calculating the residual life of such objects before conducting a survey. The authors indicates the main points that must be included in the developed methodology.

Глубокое обучение адаптивных систем управления на основе логико-вероятностного подхода

The problem of automatic selection of subgoals is currently one of the most relevant in adaptive control problems, in particular, in Reinforcement Learning. This paper proposes a logical-probabilistic approach to the construction of adaptive learning control systems capable of detecting deep implicit subgoals. The approach uses the ideas of the neurophysiological Theory of functional systems to organize the control scheme, and logical-probabilistic methods of machine learning to train the rules of the system and identify subgoals. The efficiency of the proposed approach is demonstrated by an example of solving a three-stage foraging problem containing two nested implicit subgoals