Given Level Of Reliability Research Articles

ВЫБОР ПАРАМЕТРОВ ТЕХНИЧЕСКОГО СОСТОЯНИЯ ЭЛЕМЕНТОВ ПОГЛОЩАЮЩЕГО АППАРАТА, ОПРЕДЕЛЯЮЩИХ ЕГО БЕЗОТКАЗНОСТЬ

The problems to plan and ensure a given level of reliability of mechanical systems at all stages of their design and operation occupy an important place in the problem of ensuring the quality of machine-building products. With a significant number of scientific methods and approaches to solving theoretical and applied issues of reliability theory, one of the key directions is to determine the reliability indicators of technical systems and their elements, in particular a wide range of products including sliding friction pairs with periodic impacts. The study of failure origins, from the point of view of physical-mechanical processes occurring in surface layers of elements, under the influence of external factors, allows selecting parameters characterizing the functional state of the pair, and, as a result, its reliability. For example, for sliding friction pairs with periodic impacts, such a parameter is the geometric dimensions of the conjugate elements. The decrease in the geometric dimensions of conjugate elements, due to wear, characterizes the rate of change of the initial parameter values to the maximum permissible ones determining the failure, and can be approximated by linear, power, exponential and other dependencies obtained from actual measurements. According to the obtained functional dependencies of parameter changes over operating time, it makes possible to determine the norm for the parameter regulating their pre-failure state, beyond which failure prediction is possible with varying probability, and, as a result, the reliability of the system as a whole. The use of this method to reliability forecasting through the determination of the pre-failure state of the system can be projected onto technical objects, which performance indicators are geometric parameters that ensure the performance, first of all, of the functions of the elements themselves and the entire technical system, and worn out during operation.

Probabilistic design procedure for steel moment resisting frames equipped with FREEDAM connections

In this work, the Theory of Plastic Mechanism Control (TPMC) is combined with a probabilistic method to account for the influence of random material variability. Reference is made to steel Moment Resisting Frames (MRFs) equipped with FREEDAM connections. FREEDAM connections are beam-to-column connections equipped with friction dampers to dissipate the seismic input energy. TPMC is used to guarantee that in case of destructive seismic events the structural members such as beams and columns remain undamaged. To this scope, the structure is designed to assure a collapse mechanism characterized by the activation of all the friction dampers of the beam ends and the formation of plastic hinges at the base of the first storey columns only. From the probabilistic point of view, the random uncertainties are given by the static friction coefficient of the contact surfaces and the preloading of the bolts of the friction dampers as well as the yielding resistance of the steel members. The failure domain is related to all the possible failure events, where the term “failure” concerns the development of an undesired mechanism different from the global one. Generally, the design conditions to prevent undesired collapse mechanisms are stochastic events within the framework of the kinematic theorem of plastic collapse. The limit state function corresponding to each event can be represented by a hyperplane in the space of random variables. Consequently, the failure domain is a surface resulting from the intersection of the hyperplanes corresponding to the limit states of each single failure event. Since dissipative zones (member ends or friction dampers) in the frame members are common to many different mechanisms, the single limit state functions are correlated. Therefore, the probability of failure can be evaluated by means of the Bimodal or Ditlevsen bounds by assuming that the failure events are located in series. The output of the work is a simple relationship which provides the overstrength factor of FREEDAM connections to be considered in the column design phase to account for random material variability thus assuring a given level of reliability in the application of TPMC.

Methodology for assessing the effectiveness of design and technological solutions in ensuring the service life of power connections of structures

Abstract: A methodology for designing the load-bearing capacity of power parts of machines and structures operating under variable loading conditions is presented, which allows assessing the effectiveness of design and technological solutions based on the criteria of fatigue strength, durability and guaranteed service life. The technique is based on the force calculation of parts and assemblies, the formation of an equivalent block of variable loading, the calculation of the endurance limit in a statistical aspect and the determination of the fatigue life at a given level of reliability. The presented methodology is based on a specific example of calculating and assessing the durability of the elements of the fork connector of the fin and fuselage of a passenger aircraft.

ANALYSIS OF THE PROCESS OF TRANSFORMATION OF THE TECHNICAL STATUS OF A SAMPLE OF MILITARY EQUIPMENT FOR NAVY UNITS DURING ITS LIFE CYCLE

The analysis of the existing methods of determining the effectiveness of the maintenance and repair system of new and newest types of weapons and military equipment entering service in the units of the Armed Forces of Ukraine showed that each of the existing approaches has its advantages and disadvantages. The article considers the application of adequate models for determining changes in the technical condition indicator in the form of a normalized residual resource of samples of weapons and military equipment. The proposed method of extrapolation makes it possible to determine the trend of changes in the technical condition of samples of military equipment of units of the Armed Forces of Ukraine or its development by the time of operation. This approach to modeling the processes of changes in the technical state of samples of weapons and military equipment contributes to the quantitative analysis and forecast of the dynamics of changes over time in their important parameters, namely, the characteristics of quality, condition and prospects for updating their fleet. The use of the proposed methods of assessing changes in the technical condition of a sample of weapons and military equipment during its operation will allow timely forecasting of the process of development of changes in the technical condition of a sample of weapons and military equipment and will allow to increase the readiness of samples of weapons and military equipment to perform tasks as intended. at a given level of reliability of these samples. The presented proposed method makes it possible to determine the moment in time at which the indicator of the technical condition of a sample of weapons and military equipment reaches a given or critical level and is a real step in the research of issues of quantitative determination of the level of the indicator of the residual normalized resource of new and newest samples of weapons and military equipment and in solving the task high-quality (sustainable) between-repair functioning of such samples. Keywords: sample of military equipment, technical condition, indicator of technical condition, residual normalized resource, model. extrapolation method, trend assessment.

METHODOLOGICAL APPROACHES TO THE CREATION AND USE OF SPECIALIZED SOFTWARE FOR PROCESSING AND DISPLAYING INFORMATION ON THE PARAMETERS OF THE MOVEMENT OF OBJECTS OBTAINED FROM

The article proposes methodological approaches to the creation and use of specialized software for processing and displaying information about the parameters of the movement of objects obtained from video recording devices during short tests of weapons and military equipment.
 One of the components of the abbreviated test system are digital video recording devices, which can be used as separate elements and as part of optical-electronic stations installed on mobile test objects or separately, on designated (equipped) places (sites), and must perform video registration in the specified volume and with the specified parameters.
 However, it should be noted that currently optical-electronic stations and complexes of trajectory measurements are not fully equipped with means of digital video recording and information processing, which ensure the compatible operation of means of trajectory measurements in real time. The mentioned problem was not the object of a special study.
 Therefore, the creation and use of specialized software for processing and displaying information about the parameters of the movement of objects obtained from digital means of video registration is an urgent task and provides an opportunity to further improve typical methods of determining parameters and speed up the process of processing information during shortened tests of weapons samples and military equipment.
 The purpose of the article is methodological approaches to the creation and use of specialized software for processing and displaying information about the parameters of the movement of objects obtained from video recording devices
 Thus, the proposed materials consider methodological approaches to the creation and use of specialized software for processing and displaying information about the parameters of the movement of objects obtained from video recording devices during short tests of weapons and military equipment. They are based on two main approaches, the essence of which is as follows.
 Firstly, in the optimization of the number of experiments to confirm the requirements for the purpose with a given level of reliability when conducting abbreviated tests of samples of weapons and military equipment due to the use of the most progressive, economically justified methods of conducting them, modeling test processes, using methods of accelerated tests, combining several checks when conducting one type of test and taking into account the results of checks carried out during previous tests.
 Secondly, in the creation and use of specialized software for processing and displaying information about the parameters of the movement of objects, obtained from digital means of video registration, it provides the possibility of further improvement of typical methods of determining parameters and speeding up the process of processing information during shortened tests of weapons samples and of military equipment, which in turn will speed up the decision-making procedure regarding the use of the test facility.

X-Rel: Energy-Efficient and Low-Overhead Approximate Reliability Framework for Error-Tolerant Applications Deployed in Critical Systems

Triple modular redundancy (TMR) is one of the most common techniques in fault-tolerant systems, in which the output is determined by a majority voter. However, the design diversity of replicated modules and/or soft errors that are more likely to happen in the nanoscale era may affect the majority voting scheme. Besides, the significant overheads of the TMR scheme may limit its usage in energy consumption and area-constrained critical systems. However, for most inherently error-resilient applications such as image processing and vision deployed in critical systems (such as autonomous vehicles and robotics), achieving a given level of reliability has more priority than precise results. Therefore, these applications can benefit from the approximate computing paradigm to achieve higher energy efficiency and a lower area. This article proposes an energy-efficient approximate reliability (X-Rel) framework to overcome the aforementioned challenges of the TMR systems and get the full potential of approximate computing without sacrificing the desired reliability constraint and output quality. The X-Rel framework relies on relaxing the precision of the voter based on a systematical error bounding method that leverages user-defined quality and reliability constraints. Afterward, the size of the achieved voter is used to approximate the TMR modules such that the overall area and energy consumption are minimized. The effectiveness of employing the proposed X-Rel technique in a TMR structure, for different quality constraints as well as with various reliability bounds, is evaluated in a 15-nm FinFET technology. The results of the X-Rel voter show delay, area, and energy consumption reductions of up to 86%, 87%, and 98%, respectively, when compared to those of the state-of-the-art approximate TMR voters. Also, the effectiveness of the proposed X-Rel-based TMR structure is assessed in four benchmark applications from different domains. For these benchmarks, the results show 1.59 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times$</tex-math> </inline-formula> , 2.35 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times$</tex-math> </inline-formula> , and 3.39 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times$</tex-math> </inline-formula> energy-delay-area-product (EDAP) reduction for less than 1%, 5%, and 10% output quality degradations, respectively. Finally, an image processing application is benchmarked to evaluate the X-Rel framework efficacy in the presence of errors, where the results show up to a 4.78 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times$</tex-math> </inline-formula> higher output image quality in comparison with the typical TMR voters.

Adaptive integer arithmetic coding with RLE-transform

The paper proposes a method of multilevel selective processing to increase the availability of information about critical infrastructure objects with a given level of reliability and confidentiality. This technology is based on the identification of key information at several stages of processing and adaptation of the RLE algorithm and integral arithmetic coding into a new input data structure. Thus, the last stage of processing video data by the proposed approach is considered, which is aimed at reducing the volume with the following features: further development of the method of linearization of two-dimensional transforms based on zig-zag scanning is obtained. The differences of the method lie in carrying out the vector intertransform zigzag linearization taking into account the selection of spectral components, which is defined as complementary. For the first time, a method of decomposition of a linearized transform based on the definition of a threshold has been developed. Characteristic features of the method: the threshold is found taking into account the presence in the group of different types of transformants to determine the total uneven number of non-equilibrium complementary components; the integral arithmetic coding has been improved based on taking into account the frequencies of dictionary elements (two-dictionary integral arithmetic coding). Distinctive features of the method: determination of the current code components by the decomposed working interval, depending on the capacity of the dictionaries of significant elements and the number of repetitions. This allows additionally taking into account the statistical features of the components of the RLE-structured linearized transform and reducing the length of the arithmetic code; For the first time, a transformant compression technology was created based on the reduction of various types of redundancy in groups of transformants. Characteristic features of the technology: RLE-structuring of the non-uniform complementary part of the group of transforms after their vector linearization and decomposing; the formation of two arithmetic codes according to two dictionary principles of uneven division of the working interval, depending on the type of transformants in the group.

Parametric modeling of radio engineering devices at the stage of system design

System design provides for solving the task of comparative analysis and choosing the best option for constructing a radio engineering device. Its main result should be a structural diagram of the product and an assessment of the effectiveness of its implementation. The number of possible structural options for their implementation is limited when designing radio engineering devices of a certain class, so the search for the best option is mainly determined by the costs of its implementation, provided that the requirements of the technical specifications are fully satisfied. The main way to reduce the costs of developing devices is to use high-availability modules as much as possible in the designed product, which means electronic modules that have passed certain stages of development or have at least working design documentation. Then, the task of system design is reduced to solving the task of covering the given structures of high-availability modules, and the efficiency of its solution depends to a large extent on the number of possible alternatives. The methodology of using parametric modeling to determine the best option of construction of a radio engineering device (system) is considered. It is proposed to use an information approach to assess the degree of coincidence of the parametric models of highavailability modules with the values of parameters specified in the technical specifications while maintaining a given level of reliability. The degree of coincidence is evaluated by three criteria: informativeness, adequacy, and accuracy. It is shown that the considered methodology makes it possible to solve the parametric synthesis task of the effective structure of a radio engineering device while maintaining its specified reliability. The resulting options are highly reliable because the cost estimation is performed by real developers. As information on the actual costs for possible modifications of high-availability modules is accumulated, the preliminary cost estimation procedure can be automated.

Влияние наработки и возраста на поток отказов автомобилей

The service life of cars is a key indicator for planning the replacement of outdated equipment with a new one. It is also taken into account during the technical re-equipment of the industry, the development of the material and technical base and has a direct impact on the final results of the enterprise. It is shown that limiting the maximum age and service life of cars is one of the ways to increase their reliability, safety and efficiency. The purpose of the article is to develop a methodology for determining the rational service life of cars, providing a given level of reliability of transport and technological services. The scientific novelty of the research lies in the establishment of patterns and the development of mathematical models of the influence of age and operating time on the parameter of the failure rate of cars. The methodological basis of the work was the systematization of research works carried out earlier on this topic, regulatory documents, scientific and technical literature, as well as methods of mathematical statistics, elements of a systematic approach, methods of economic analysis and expert assessments. Methods of determining rational service life of cars are considered. It is established that each of the known methods has a limited scope of use. So, the schedule built for the implementation of the technical and economic method does not always have a minimum. It is proposed to set the maximum operating time according to the admissible probability of failure. At the same time, it is necessary to take into account not only the mileage since the entry into operation, as it is accepted in most known methods, but also car operation intensity. It is shown that in the general case, there is no statistically significant linear correlation between car age and mileage since the entry into operation. One-factor and two-factor models of the regularities of the influence of these indicators on car failure intensity were developed. On the basis of statistical data on failures of cars of different ages and at different mileages since the entry into operation, the adequacy of the proposed models was checked and the numerical values of their parameters were established. Based on the obtained dependencies, a method for determining the age limit of cars, taking into account their operation intensity, was developed. The effect of it is formed due to a more accurate determination of the service life of cars, which affects the reduction of the number of failures, losses from downtime in current repairs and downtime of the main production of the enterprises under discussion. Further research in this area should be directed to the development of a methodology for adjusting the service life of cars, taking into account their operating conditions.

EVALUATION OF THE EFFICIENCY OF USING A MIXED SYSTEM OF MAINTENANCE AND REPAIR OF ROAD VEHICLES OF ROAD TRANSPORT

The article argues the relevance of determining the efficiency of the mixed system of maintenance and repair of road vehicles. Improving the system of maintenance and repair of road transport is one of the main ways to increase the efficiency of motor transport enterprises. This is due to the high growth rate of work performed, the significant complexity of the design of modern vehicles and the variety of implementation of new maintenance strategies and diagnostic methods. Significant complications in the design of components and units of modern road vehicles, increasing their functions, more busy modes of operation of components, units, etc. - significantly exacerbated the problem of traffic safety, which is largely due to the quality of maintenance and repair. The urgent need to improve the system of maintenance and repair is due to changes in the technical condition of automotive equipment and the requirements for maintaining the working condition of vehicles during operation. An analysis of existing maintenance and repair strategies has shown that each has its advantages and disadvantages. The combination of advantages of each strategy and elimination of shortcomings will lead to the creation of a mixed system of maintenance and repair, which along with high-quality staffing of repair companies and equipping them with modern diagnostic equipment will increase the readiness of road vehicles, technical efficiency and efficiency quality of operation, reduce maintenance and repair costs at a given level of reliability. © О. М. Рікунов, В. І. Кужелович, 2022 Keywords: road transport vehicles, maintenance and repair system, preventive maintenance system, average total duration of maintenance and repair, technical readiness coefficient, technical utilization coefficient, economic feasibility

Risk analysis of management of water systems in the Russian Federation

The management of the water management complex is based on the analysis of a large number of processes developing in systems that are techno-natural in nature, on the one hand, and in complex socio-economic systems affecting the whole society as a whole, on the other. The management methods implemented in practice today are based mainly on the analysis of the functioning of individual parts (individual processes) of the system, ideas about the processes under consideration are often not consistent, especially when it comes to technical and social systems. Regulatory management methods, including technical regulation, are considered separately. Socio-economic processes at different levels of temporal and spatial organization are investigated and predicted independently. At the same time, of course, regulatory legal knowledge is taken into account, but resource restrictions may fall out or be ignored, society is immune to instructions and recommendations lowered from above, legal nihilism takes place, the problem of qualification of decision-makers arises, etc.Certain possibilities for analyzing such situations are provided by risk theory methods. The purpose of the article is to analyze the risks arising at various stages of justifying water management measures, from design to strategies for the development of the industry as a whole. In particular, traditional methods of engineering calculations are considered, which ensure a given level of reliability of the designed water construction facilities in relation to hazardous impacts (loads), which are based on the concept of design probabilities. This approach provides a normative level of reliability, but does not guarantee the economic optimality of decisions made, is insufficient to implement the social functions of measures and structures, and is difficult to analyze environmental problems. Obtaining quantitative estimates of the parameters of structures and measures, carried out on the basis of probabilistic approaches, should be based at least on taking into account the possible consequences of decisions taken, as well as on damage assessments expressed in the form of relevant risks.

MATHEMATICAL MODEL OF COMPUTER SYSTEM RELIABILITY IN RESIDUAL CLASSES

The subject of the article is the construction of a mathematical model of the reliability of a computer system (CS) that operates in a system of residual classes (RNS). This mathematical model is based on the use of structural sliding reservation. The purpose of the article is to increase the reliability of the CS, which operates in the system of residual classes, as well as to calculate and compare the reliability, in terms of the probability of failure-free operation, of the CS in the RNS and the ternary computing system, which operates in the positional binary number system (PBNS). Tasks: to analyze the influence of the number system used on the reliability of the CS; to investigate the properties of the RNS and determine their influence on the structure of the CS in the RNS; build a mathematical model of reliability and, on its basis, perform the calculation and comparative analysis of the reliability of the CS in the RNS and the tripled CS in the PBNS. Research methods: methods of analysis and synthesis of computer systems, number theory, coding theory in RNS, reliability theory. The following results are obtained. The paper shows that the provision of a given level of reliability in the design of the CS using the RNS is due to the presence of various types of redundancy at the same time: structural, informational, temporal, functional and load. In RNS, these types of redundancy can be effectively used to improve the reliability of the CS. The CS in the RNS represents a computational structure that is identical in structure and principle of operation to the sliding structural redundancy model in the PBNS in the case of a loaded (hot) mode of operation of the redundant elements. Proceeding from this, the paper presents a mathematical model of the reliability of the CS in the RNS. In this paper, the calculation and comparative analysis of the reliability of a tripled computing structure in a PBNS with an ideal majority element and a CS in an RNS with an ideal reliability automaton are carried out. Conclusions. As shown by the results of calculations and comparative analysis in some time intervals of operation, the probability of non-failure operation of the CS in the RNS is higher than the probability of non-failure operation of the aircraft in the PBNS with a tripled majority structure. This implies the effective use of the RNS to improve the reliability of the CS.

Method of compression and ensuring the fidelity of video images in infocommunication networks

Subject research in the article is the methods of compressing video images under conditions of ensuring the desired level of their fidelity in the delivery process using infocommunication networks. The goal is to develop methods of encoding video images for increasing the level of their compression in the conditions of ensuring required reliability. Task: to substantiate the approach regarding the structural clusterization of transformed video segments in the conditions of preserving their reliability; to develop a method of structural and statistical coding of transformants in the spectral-cluster space; conduct a comparative evaluation of the effectiveness of various methods of encoding video segments. The methods used: mathematical models for estimating the amount of statistical and structural redundancy in the clustered spectral space of video segments; methods of statistical coding. The following results have been obtained. The potential effectiveness of representing a transformant in clustered space by the number of series of units in binary description of their components has been substantiated. A method of structural-statistical coding in the spectral-cluster space has been created. The basic component of this technological approach is the evaluation of the estimates regarding the potential ability to eliminate various types of redundancy in the current cluster. Here, the amount of redundancy is reduced considering the statistical and structural features of the cluster. The comparative evaluation revealed the advantages of the created method over coding methods in standardized platforms. The advantage is achieved in terms of the peak signal-to-noise ratio by at least 30%. and in terms of a compression ratio by an average of 12 %. Conclusions. The scientific novelty of the obtained results is as follows: for the first time, a method of structural-statistical coding of video segments in spectral space based on their clusterization has been created. The differences of the method lie in the fact that the component of the transformant is simultaneously interpreted as an element of the statistical and combinatorial cluster space; the potential capabilities of eliminating various types of redundancy in the clustered transformant are considered. This provides an increase in the level of compression of video images for a given level of reliability.

Оценка экономической эффективности подготовки операторов сложных систем

The possible ways of economic evaluation of the effectiveness of training operators to manage complex technical systems are analyzed. The variants of evaluation are considered, taking into account the achievement of a given level of reliability when performing management tasks, the professional suitability of operators for this type of activity based on their individual characteristics and the characteristics of the tasks being solved.

ОПТИМИЗАЦИЯ И НАДЕЖНОСТЬ СТРОИТЕЛЬНЫХ СИСТЕМ

A new method for optimizing construction systems is proposed while taking into account the given level of reliability of their functioning. Proposed method is effective for problems in which the vector of optimal parameters of a building system belongs to one or more functional constraints. In practice, such tasks constitute a substantial majority. The main advantage of this method is that the construction costs for the production of the building system or its elements are minimal.

Development of a method for designing specialized machinery based on a hinge tractor

The method of designing frames of special machines for road construction and public utilities is considered, which allows you to design special machines with a given level of reliability and durability. The technique allows using modern computer modeling systems to carry out constructive refinement of the base tractor frame using experimental and mathematical modeling data. Using the design feature of tractors of the T–150K family, namely the presence of an articulated joint, it is possible, using a modular principle, to quickly design various machines for various industries. However, in order to design reliable machines, one must have a methodology for designing such machines. There is currently no such technique. When designing special machines, designers perform calculations only for working equipment. But as practice shows, the critical elements of the machine in this case, the support of the vertical hinge of the tractor frame during the operation of the pressurized machine (wheeled bulldozer and front loader), experience shock loads that lead to the destruction of the frame of the base tractor. The purpose of the article is to develop a methodology for designing a complex of road–building machines on the basis of mass–produced tractors with an articulated frame produced by public limited company "KhTZ".

ЗАДАЧИ И СТРАТЕГИЯ УПРАВЛЕНИЯ КОНФИГУРАЦИЕЙ СЕЛЬСКОЙ МИКРОСЕТИ, СОДЕРЖАЩЕЙ ВОЗОБНОВЛЯЕМЫЕ ИСТОЧНИКИ ЭНЕРГИИ

A significant disadvantage of rural distribution electric grids of 0.4 kV is the lack of the ability to operate their configuration. This disadvantage leads to a decrease in the reliability of electricity supply and significant damage to rural consumers from interruptions in electricity supply. A promising direction is the introduction of distributed generation based on renewable energy sources (RES), electricity storage devices into the structure of rural electric grids and the construction of microgrids based on them. However, the issues of building rural microgrids have not been worked out today, the search for rational options for their structure is being conducted all over the world, the development of equipment for their construction is underway. Therefore, the purpose of the research presented in the article is to determine the tasks and strategies for operating the configuration of rural microgrids containing renewable energy sources (RES) based on the use of means of partitioning and reserving the electric grid, that is, means of controlling its configuration and means of monitoring the parameters of its operation modes. As a means of partitioning and reserving the electric grid, it is proposed to use multi-contact switching systems installed at the points of branches in the grid and equipped with sensors for the parameters of the grid operating modes. The use of multi-contact switching systems allows you to implement a flexible change in the grid configuration when changing its operating modes. Power supply sources are also equipped with sensors. The data from the sensors is transmitted to the virtual power plant, which monitors the operating modes of the grid and forms commands for controlling its configuration. This allows you to monitor the operating modes of grid sections and power supply sources, identify normal, emergency and post-emergency modes and make the necessary changes to the grid configuration in a timely manner. As a strategy for the operation of an electrical grid containing renewable energy sources and configuration operating tools, a strategy is proposed that assumes the maximum use of the energy generated by renewable sources when the restrictions are met – a given level of reliability of power supply to consumers and the quality of electricity supplied to them

Methods of formalized quality assessment of intelligent transport systems

The purpose of the paper is to identify the main problems of creating software systems with a given level of reliability for intelligent transport systems. Considering the importance of this approach and the gained experience, the paper discusses design solutions to ensure software reliability in the development process. The paper is based on domestic and foreign experience of software design for intelligent information systems, which include transport systems. The issues of achieving a given level of software reliability during the control process are considered taking into account the continuation of the development process. It also reflects efforts to model and evaluate the reliability of software systems by considering the most common types of software reliability assessment models during development, as well as to predict the reliability during maintenance. The emphasis is upon detecting and correcting software errors.

Management of the \u201cbuilding-base system\u201d action, using a life cycle model

This research aims to highlight the problem of creating various models that reflect the life cycle of the “building-base” system, and link the reliability of this system with its technical condition. Based on the proposed model of the life cycle “reconstructed building-base”, it is possible to regulate the condition of the building towards its restoration, changing the category of technical condition to higher and obtain new, adequate to the current state, reliability indicators. During the operation of this model, it is possible to control the system management on the basis of the obtained quantitative values of reliability. The result of the reliability calculation is the determination of such a technical solution of strengthening the “building-base” system, which will provide a given level of reliability. The research provides an example of the calculation of an operable monumental building before and after its restoration.

Energy-efficient air conditioning system of a data processing center

BACKGROUND: Currently, because of the rapid development of digital technologies, an increasing amount of computer computing power is required where data processing centers are built, which sometimes require power consumption in the megawatt range. For stable year-round operation of data centers, reliable engineering is required, which includes air conditioning systems (ACS) for year-round use with a given level of reliability. Several traditional methods of data center cooling are available, namely, precision air conditioners based on vapor compression refrigeration machines (PCRMs) and systems with intermediate coolant (so-called chillerfancoil systems). However, in modern settings, when the required capacity of data centers increases every year and the framework for environmental friendliness and energy efficiency of installations becomes stricter, new, more energy-efficient, and environmentally friendly solutions for data center cooling is needed.&#x0D; AIM: This study aims to compare the proposed energy-efficient ACS with combined vapor compres-sion and indirect-evaporative cycle with the most commonly used ACSs in data centers and to deter-mine the boundaries of transition between the operating modes of the proposed ACS in a data center operating in Moscow as an example.&#x0D; METHODS: This study employs the following methods: analysis of existing data center cooling sys-tems, determination of a typical design set of outdoor air parameters in the region under consideration, and calculation by comparative analysis of the energy consumption of the proposed and traditional ACSs for data centers.&#x0D; RESULTS: From our study, the different ACSs currently used for data centers, namely, precision air conditioners and chillerfancoil systems are highlighted. The main components of each system, the advantages and disadvantages observed in the design, installation, and commissioning processes, and the operation of the systems are described. An alternative ACS that combines PCRM and indirect-evaporative cooling is proposed. The comparative analysis of the proposed scheme and traditional so-lutions demonstrates that the combined ACS allows significant reduction in the energy consumption for data-center cooling. Therefore, under the conditions in Moscow, the proposed system for a particu-lar year will consume energy that is two times less than a chillerfancoil system with free cooling and 2.5 times less than a system with precision air conditioners that operate on the traditional vapor-compression cycles.&#x0D; CONCLUSION: The comparative analysis of the proposed energy-efficient ACS with combined vapor compression and indirect-evaporative cycle with the most commonly used ACS in data centers con-firms its high energy efficiency and provides greater environmental safety. The boundaries of the tran-sition between the operating modes of the proposed ACS are determined in a data center that operates in Moscow as an example, which exhibits high energy efficiency and reliable operation.