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The purpose of the article is to develop a methodology for evaluating stochastic processes in complex systems using the example of a three-processor computer system, which will make it possible to increase the effectiveness of monitoring the functioning and management of such objects. During the research, the methods of system approach, analysis and synthesis, stochastic and simulation modeling were applied, based on which the behavior of a three-processor computing system was reproduced under different conditions; simulations made it possible to reveal the mechanism of the system and verify the stochastic model; Markov chains made it possible to simulate the transitions of a computer system from state to state and to estimate the probabilities of system states as functions of time using numerical methods. Proposed simulation model in the article allows determining the states of the processors, calculate their load periods depending on the total time of operation, and determine the moment of time at which transient processes are completed and the computer system reaches its balanced mode of operation. The theoretical and practical significance of the research lies in the further studying of the existing and the development of new theoretical and methodological provisions for increasing the efficiency of the analysis and evaluation of stochastic processes in complex systems.

The article presents simulation modeling as a mathematical basis for the study of logistic systems. The object is pharmaceutical logistics - logistics chains of pharmaceutical companies. Attention is focused on the problems of functioning of domestic pharmaceutical logistics in the conditions of military realities. The expediency of using simulation modeling technologies to reproduce the changing, force majeure conditions of functioning of the supply channels of finished pharmaceutical products is substantiated. Models of one-level and two-level sales channels for pharmaceutical products, built using the discrete-event simulation paradigm on the software platform of the AnyLogic system, are presented. The results of the simulation are illustrated by fragments of simulation experiments based on the materials of the pharmaceutical company FARMAK. [ABSTRACT FROM AUTHOR]

A comprehensive mathematical model of a small hydroelectric power plant for a simulation modelling system has been developed. The model consists of the following simulation mathematical models: a hydraulic turbine with an adjustable guide device, its hydraulic network, an electromechanical system, and a reservoir model. These simulation models are based on the differential equations of electrical, mechanical, and hydraulic equilibrium and are designed to determine the values of currents, speeds, and performance of steady-state operating modes, taking into account the nonlinear properties of the equation parameters. To improve the adequacy of the complex model, a refined simulation model of an induction machine with loss detailing was applied and verified to specify the efficiency and permissible heating power in the motor and generator modes. The losses in steel are ac-counted for by their equivalent circuits. The information on the calculated values of the operating mode parameters allows deter-mining the value of the efficiency indicators of the hydroelectric power plant system under different operating conditions, which makes it possible to formulate optimal modes. Based on the results of a series of calculations with varying static head and open-ing of the blades of the axial guide apparatus, the regularities of changes in their optimal ratio according to the criterion of maximum electric power generated per unit of reservoir water flow used in the formation of the power plant's shunting mode were investigated. Based on the information on the value of the natural flow and the characteristics of the turbine unit, a stable level of static head is determined, which ensures the maximum generated electric power. The power plant's shunting mode was studied to determine the impact of changing the number of simultaneously operating units on the amount of electricity generated and changes in its capacity (the possibility of reducing the unevenness of the generated power by almost two times and increasing the minimum capacity by 30% was shown). Compared to the steady-state flow, the shunting mode provides an almost twofold increase in electricity generation and a threefold increase in efficiency, taking into account the differential cost of electricity by time of day. [ABSTRACT FROM AUTHOR]

The article is dedicated to determining the energy indicators of a generating complex with stochastic wave energy gen-eration. The aim of the study is to compare the energy indicators and power consumption coefficient of wave energy generating complexes' simulation models with magneto-electric generators operating at variable speeds under resistive and resistive-capacitive loads with rectified voltage. The analytical method is employed to calculate the parameters and energy indicators of the magneto-electric generator. The calculation includes inductance, resistance, and voltage gen-erated by the rotor with permanent magnets in the three-phase winding of the magneto-electric generator for electrical circuit modeling with and without a three-phase current rectifier, as well as active-reactive and active loading. The rotor rotation frequency varies harmonically with the same period and amplitude for all electrical circuits. The deter-mined current in the electrical circuits is used to calculate the generator's electromagnetic field and energy indicators. Comparisons are made for circuits with active and active-reactive loads, including power consumption, power losses in the stator winding, power output from the generator, and the power consumption coefficient of wave energy. The com-parison of energy indicators is conducted under the condition of equal rotor oscillation frequency and shaft torque, achieved by varying the load resistance. Bibl. 10, fig. 8, table.

The relevance of the study is to develop an effective system for controlling the pressure in the air supply in motorised breathing apparatus to ensure effective protection of employees from dangerous aerosols and improve their health. The goal was to create an automated air pressure control system in a motorised breathing apparatus using a proportional-integral-derivative controller. For this purpose, the simulation method was used. In order to avoid unforeseen situations of deterioration of the level of protection, the structure of the pressure control system of a motorised respirator has been developed with the selection of the appropriate controller based on the obtained dependences of the influence of the parameters of the breathing mode and the amount of pressure in the under-mask space of the respirator, which ensures an appropriate comfortable mode of operation. This allowed developing a simulation model with a PID controller that would provide the appropriate pressure values within the permissible limits (50-370 Pa). It is proved that the proportional-integral-derivative controller maintains the pressure in the respirator mask within certain limits both with an increase and with a decrease in the control signal, preventing excessive fluctuations in the controlling variable, which leads to an extension of the service life of the filter elements and a reduction in electricity consumption for the operation of the fan motor. Based on modelling the operation of the pressure control system in different modes of operation, it is shown that when using a PID controller with defined parameters, the system provides compensation for changes in air pressure in the under-mask space of the respirator in different breathing modes of the user. The results can find practical applications in the field of safety and health, in industrial environments where workers are at risk of inhaling dangerous aerosols, such as toxic particles, gases, or other harmful substances

The problem of researching weapons distribution strategies to ensure effective combat operations in a military conflict zone is being formed and solved. The relevance of the study is related to the solution of the task of an operational-tactical nature in order to establish the military parity of forces in the conditions of the introduction of various equipment into the combat zone (CZ), which has different characteristics of combat capability from the set of warehouses and suppliers, with long supply chains. The problems that arise when establishing military parity of forces with the help of various weapons with different indicators of combat capability, the limited capabilities of suppliers, and the complications of supply logistics are analyzed. It is shown that asymmetric solutions, according to military equipment, are possible because of the use of technological innovations and high indicators of the combat effectiveness of weapons. It was concluded that the establishment of military parity of forces is possible thanks to the use of rational strategies for the distribution of weapons, which is an urgent problem in the conditions of modern hybrid warfare. Thus, this paper proposes a study of possible strategies for the distribution of weapons by CZ in conditions of threats of martial law of the country. The current study creates models that allow for the evaluation of possible arms distribution strategies, considering the diversity of military equipment, limited capabilities of suppliers, and risks associated with long logistics supply chains. Using set-theoretical analysis, methods of combinatorics, and enumeration theory, a systematic presentation of the distribution process of weapons is created. Possible strategies for the distribution of weapons by CZ to establish military parity of forces are formed and analyzed. Optimization models have been created for the rational distribution of military equipment under conditions of limited capabilities of manufacturers in terms of costs, production terms, and risks of arms supply. A simulation model is being developed to study the dynamics of the logistical process of distribution and supply of weapons in agent representation using the AnyLogic platform. Modeling allows you to analyze the impact of threats to the main indicators of the distribution and supply of weapons. An illustrative example of the distribution of weapons by CZ of a military conflict is presented. The scientific novelty of this research is related to the solution of the actual problem of the rational distribution of various military equipment by CZ in the conditions of modern hybrid warfare. The results of this study should be used for operational-tactical planning of the logistical process of distribution and supply of weapons to solve the problem of establishing military parity of forces in the CZ.

The article is devoted to the study of the issue of banks’ risk management. Risk management is a complex but necessary process to ensure the financial stability of banks. Research and assessment of banks’ risks helps banks understand and manage risks, make more informed decisions about granting loans, investing and other operations. Risk modeling is an important part of risk management in banks, so the article proposes improving the methodology for assessing the level of risks of banking activities, which, on the basis of forecasting methods and simulation modeling, allows to improve the validity and quality of managerial decisions in the field of management of financial activities of a bank. The task of risk assessment is a central element of the risk management system in banks. In order to improve the methodological base, the article proposes a conceptual scheme of modeling the risks of banking activity, which includes four blocks: development of currency risk assessment models; development of credit risk assessment models; stress testing of banking risks; making decisions to stabilize the financial condition of the bank in each of the proposed scenarios of modeling the risks of banks’ activity. In accordance with this, on the basis of the carried out study of the bank’s financial statements and methods of assessment and analysis of risks of banking activity, the following simulation models have been developed: a model for assessing the level of currency risk; a model for assessing credit risk and determining the amount of its reserve according to national and international standards; a complex risk assessment model. After building and examining the models, the methods of system dynamics were used, namely: simulation modeling, stress testing, and sensitivity analysis. Simulation modeling has become an effective tool for studying the risks of banking activities, as it made it possible to create virtual models of banking operations and test them on various risk scenarios. Stress testing allowed to study the impact of shock events on the financial stability of the bank. Sensitivity analysis was used to identify the most sensitive parameters of the model and to determine how changing these parameters affects the model results.

The question of building the architecture of the multi-agent environment of the simulation model of the pricing process, as a space of heterogeneous interconnected organizational, informational, technological and economic interactions of the simulated agents of the pricing process, is considered.Using the example of a complex organizational and technical system (COTS) of the electricity micro-market in local electric power systems, the set of agents surrounding them and ensuring the vital activity of the COTS of pricing is formalized, consisting of classified internal agents and environmental agents with a definition of their functional purpose. It was established that a set of partially observable influence factors of subjects of the electricity micro-market external environment are additionally formalized in the multi-agent pricing system as communication agents with stochastic, dynamic. but with discrete fixation of distinct states of observation processes in this environment. As a result, the simulation model of the pricing process is presented as a heterogeneous distributed multi-agent system. [ABSTRACT FROM AUTHOR]

Views on the solution of conceptual issues regarding the methods and technologies of building local simulators for training personnel in the energy industry are presented. Information technology for building local simulators based on scenario-simulation modeling of energy equipment and personnel activities is proposed. Methods of designing scenario structures and implementing methods of model construction in the development of local simulators are considered. The need for further development and improvement of technology due to the problemoriented adaptation of the latest software packages is indicated, which would enable experienced experts in the energy industry to massively create training tools in a convenient and understandable interactive environment. [ABSTRACT FROM AUTHOR]

The main attention in the article is given to the development of the method of nodal transformation of the pricing process in the electricity market. The sequence of implementation of the main constructive stages of its development and further use is given, such as: descriptions of the pricing process; formalization of the pricing process; development of computational procedures for building a simulation model of the pricing process. A distinctive feature of this method from the known and described in the scientific literature is the direct connection of the dynamic energy flow at all stages of the technological process of production, transmission and distribution of electricity with the economic flow. The computational procedures of the method are implemented using the discrete-event approach. The method is designed to build a simulation model of the pricing process in the electricity market, which along with a system of short-term price forecasting models in different market segments, becomes the key in the information and methodological support of multi-agent environment for the market agents interaction. References 13, figures 2. [ABSTRACT FROM AUTHOR]

According to the relevance of the study, the new challenges of the financial environment, the growing dynamism of globalization and digital changes in national and global financial relations. Conceptual awareness of financial transformation necessitates the development of new tools for scientific knowledge of the prospects for the development of the financial market of Ukraine in terms of digital imperatives. The purpose of the study is to identify innovative ways of long-term development of the financial market of Ukraine in terms of digitalization of society. The object of research is the latest financial and digital processes of prospects for the development of the national financial market of Ukraine in terms of digital transformation. The research methodology is special and the latest approaches to the development of financial relations. Prospects for the development of financial relations are innovative: regulatory framework; system-institutional structure; functional and instrumental base; technological and digital transformation; financial and digital security; financial inclusion.

The article substantiates that in the conditions of digitalization of the Ukrainian economy, the decision of the online buyer to choose and purchase goods is influenced by reviews/comments on the Internet. It is determined that the successful online activity of the retailer, including a positive image and the desired level of sales, is provided by her/his ability and skills to correctly respond to the reviews/comments of the online buyer. On the basis of the systematized literature sources and a comparative analysis of the results of empirical researches of well-known leading scholars and economists at the national and international levels, the author presents the typology of reviews/comments of the online buyer, which defines the specifics of the retailer’s response. The need and importance of developing alternative patterns of timely response of retailers to reviews/comments of the online buyer in ever-changing realities is proved with arguments. Appropriate recommendations to the retailer regarding an adequate response to the reviews/comments of the online buyer are suggested according to the typology, their differences are interpreted. A simulation model of the retailer’s response to negative reviews/comments of the online buyer with desensitization of the target audience according to the context of the current situation has been developed. In the development of this simulation model, using the «BP Simulator» software to simulate business processes, a relevant low-abstraction approach was applied, taking into account management features at all strategic levels, and providing for the possibility of modifying the model based on the scale and metrics of the retailer’s practical activities. The results of the practical approval of the developed simulation model show the feasibility of its implementation by retailers of different market segments to improve the efficiency of online activities.

Purpose. Modern algorithms for choosing the shortest route, for example, the Bellman-Ford and Dijkstra algorithms, which are currently widely used in existing routing protocols (RIP, OSPF), do not always lead to an effective result. Therefore, there is a need to study the possibility of organizing routing in in the railway network of information and telecommunication system (ITS) using the methods of artificial intelligence. Methodology. On the basis of the simulation model created in the OPNET modeling system a fragment of the ITS railway network was considered and the following samples were formed: training, testing, and control one. For modeling a neural-fuzzy network (hybrid system) in the the MatLAB system the following parameters are input: packet length (three term sets), traffic intensity (five term sets), and the number of intermediate routers that make up the route (four term sets). As the resulting characteristic, the time spent by the packet in the routers along its route in the ITS network (four term sets) was taken. On the basis of a certain time of packet residence in the routers and queue delays on the routers making up different paths (with the same number of the routers) the optimal route was determined. Findings. For the railway ITS fragment under consideration, a forecast was made of the packet residence time in the routers along its route based on the neural-fuzzy network created in the MatLAB system. The authors conducted the study of the average error of the neural-fuzzy network`s training with various membership functions and according to the different methods of training optimization. It was found that the smallest value of the average learning error is provided by the neuro-fuzzy network configuration 3–12–60–60–1 when using the symmetric Gaussian membership function according to the hybrid optimization method. Originality. According to the RIP and OSPF scenarios, the following characteristics were obtained on the simulation model created in the OPNET simulation system: average server load, average packet processing time by the router, average waiting time for packets in the queue, average number of lost packets, and network convergence time. It was determined that the best results are achieved by the simulation network model according to the OSPF scenario. The proposed integrated routing system in the ITS network of railway transport, which is based on the neural-fuzzy networks created, determines the optimal route in the network faster than the existing OSPF routing protocol. Practical value. An integrated routing system in the ITS system of railway transport will make it possible to determine the optimal route in the network with the same number of the routers that make up the packet path in real time.

Topicality. Necessity of reducing ships’ downtime during grain transshipment from port elevators requires intensification of handling operations. It can be provided not only by using transport mechanisms of greater capacity, but also by threadtransport lines operations automation, which will eliminate possible human operator errors. Creation of automatic control systems, in turn, requires development of mathematical and simulation models of thread-transport lines, an integral part of which are weigh hoppers of periodic action. Objective. To create simulation model of weigh hopper operation, which reflects its properties as a control object. Method. Known differential and algebraic equations of weighing in weigh hopper are used. They include influence grain weight on its mechanical system as well as dynamic force which grain creates during falling. Simulation models for MatLab/Simulink were created on the basis of these equations. Results. Computer experiments with weigh hopper models which include simulation of different operating conditions were planned and carried out. Trends were obtained, which define effectiveness of its operation. Conclusions. Effectiveness of weighing process is defined by optimal combination of weigh hopper productivity and its dynamic inaccuracy. To increase productivity weighing cycle must be reduced. However, this reduction is limited by time, which is necessary for damping of mechanical system oscillations.

Problem. The increase in the level of motorization and in the concentration of vehicles in major cities over the past decade has led to an intensive increase in traffic on the main streets of Ukrainian cities and, as a result, the number of involuntary stops has increased, the speed of traffic flows has decreased, resulting in a cut of the traffic speed and a significant increase in the level of pollution of the environment. Improving the conditions of road traffic in modern cities requires the application of a whole complex of architectural, planning and technical measures. While the implementation of road, architectural and planning measures requires both a sufficiently long period of time and significant capital investments, traffic management measures can provide an immediate effect, and in some cases these measures are the only means of solving transport problems in conditions of limited territorial resources of cities. Purpose. The goal is an analytical and experimental assessment of the delay time at a controlled intersection before and after expanding the phase of the left-turn traffic of the main highway in a three-phase traffic light regulation cycle on a city highway with a central median. Methodology. An analytical approach has been used for developing a model of the delay of vehicles at a controlled intersection, the adequacy of which has been assessed with a simulation experiment conducted in the Vissim software environment using as an example the city highway with a central median. Results. It has been established that the created analytical dependence of the delay of vehicles at a controlled intersection has a narrow field of use that is only at low levels of loading the lane of traffic. This makes it clear that there is a need to develop the delay models that give an adequate valuation of the delay for all levels of loading. The proposed extension of the phase of the left-turning traffic flow is a common solution for similar traffic lights objects and can significantly reduce the waiting time. Novelty. The developed analytical model is based on generally accepted driving conditions at isolated controlled intersections, but it is completely original. The quantitative estimation of the effectiveness of the given improvement of the traffic light cycle has been obtained for the first time. Practical value. The proposed and justified improvement of the traffic light cycle can significantly reduce the delays of vehicles at controlled intersections with a three-phase traffic light control cycle, similar to the one considered in the paper.

In the conditions of competition and instability production companies forced continuously improve the production process and develop new innovative technologies and equipment in order to maintain their positions in the market. An important role in this play by improving the methods of planning and managing the process of production development, development of innovative products and forecasting measures to adapt to changing requirements of the external and internal market. This paper consider a multiphase sequential technological process (STP) with a branched structure at each phase of the production process. For the Poisson flow of receipt and processing of parts, a mathematical model proposed in the form of multi–channel QS with waiting and queue restriction. On this model, the criteria for evaluating the work of the STP formed and cost models synthesized for solving the problems of innovation and optimization of the STP. For each phase of the production process, the problem of evaluating the effectiveness of innovative equipment upgrades and the problem of selecting the optimal amount of equipment has solved. If there is a discrepancy between the flow of receipt and processing of parts of this mathematical model, the values of the initial criteria determined by the results of a certain number of repeated simulation of the STP operation. Ref.11, pic. 2

Based on the analysis of literature sources, the key scientific and practical tasks of improving and developing the pricing system of the current model of the electricity market in Ukraine "Competition at all levels" have been identified. The formulation of the problem of building a multi-agent simulation model of the pricing process in the electricity market as a complex dynamic system of decentralized interaction between manufacturing agents, wholesale and retail suppliers, energy traders and aggregate electricity consumers is considered. [ABSTRACT FROM AUTHOR]

The purpose of the paper is the possibilities of estimating the expected balance of capacities in the combined power system. A feature of the combined local system with solar and wind power is the random fluctuations of current capacity due to changes in weather factors. Means such as energy storage and auxiliary local generators are used to balance electricity generation and consumption. The object of research is hybrid power systems that have the properties of a local grid. The elements of the system are wind and solar power plants, power balancing devices, as well as electricity consumers. The research method is a mathematical modeling of random processes of energy consumption and generation, which allows us to analyze the current power balancing and obtain integrated characteristics of the energy balance. The operation of the balance regulating means is presented as a dynamic system, and balancing is considered as a superposition of random processes of generation and consumption. The peculiarity of the study is the simultaneous consideration of rapid changes of wind and solar, variability of the load and the possibilities of current regulation. Analytical research allows us to determine the characteristics of the probability distribution of the resulting processes. An adaptive simulation model with the possibility of variation of input parameters is proposed, which present the processes of energy generation and load taking into account the intermediate control powers. As a result of the research, a method of presenting the current states of the power system is proposed, which allows us to obtain estimates of probable modes. The model allows the construction of many states of the system and the search for optimal solutions. The significance of the obtained results is the proposed research method for the calculation of the required indicators, and some practically important estimates are obtained. Bibl. 16, fig. 8. [ABSTRACT FROM AUTHOR]

Copyright of Radio Electronics, Computer Science, Control is the property of Zaporizhzhia National Technical University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A review and analysis of publications devoted to solving scientific and practical problems of the development of the electric energy (e/e) market as a complex organizational and technical system (SOTS) is given. The subsystem of pricing management is highlighted, as its component part, as a separate object of organizational management. The urgency and necessity of creating a simulation model of the system for managing the pricing process in the electricity market with the direct participation of market entities is substantiated, the main purpose of which is to study the scientific and practical problem of improving the methodological pricing tools. Based on the analysis of modern methods of simulation modeling of management processes in the SOTS, the choice of a multi-agent approach as the main one for building a simulation model of pricing processes in the electricity market is justified. [ABSTRACT FROM AUTHOR]

The article is aimed at studying the issue of simulation modeling of competitive position according to the level of anti-crisis sustainability and the level of system provision of anti-crisis sustainability of enterprise in the competitive environment. The scientific-methodical approach is developed, allowing to form analytical parameters of anti-crisis sustainability of enterprises in two informative aggregates: indicator of competitive position according to the level of anti-crisis sustainability of enterprise and indicator of the level of system provision of anti-crisis sustainability of enterprise. A practical technology of simulation modeling and scenario approach is presented in terms of formation of competitive position according to the level of anti-crisis sustainability and system provision of anti-crisis sustainability of enterprise, including setting of tasks and building a simulation model. A visualization of the simulation model of the competitive position according to the the level of external anti-crisis sustainability and the level of system provision of the external anti-crisis sustainability of enterprise is provided with graphical means of the СКМ Maple. It is substantiated that the use of simulation modeling and scenario approach results in increasing the opportunities for the activities of enterprises and allows to strengthen their positions in the competitive environment.

The aim of the article is to form an integrated model to forecast, identify a financial crisis and minimize its spread to the real economy. The conceptual scheme reflecting the investigation of the transmission of a financial crisis to the real economy is presented. It is based on the hypothesis that the development of a crisis in the financial sector of the economy precedes a crisis in the real economy, but it is possible to mitigate the consequences of the former and partially manage the crisis in the real economy by influencing the channels of its transmission at different stages of penetration. It is proved that the most appropriate for forming an integrated model of the transmission of a financial crisis is the use of simulation models, since such models allow testing the possibility of preventing the transmission of a financial crisis to the real economy. Building a plan of experiments for the simulation model is based on the Graeco-Latin square methodology, which is due to the effectiveness of this tool in limiting the studied data ranges. In order to evaluate the results of the conducted experiments and choose an effective management model that will correspond to an optimal variant of crisis prevention, Harrington’s desirability function is chosen, which is based on the idea of converting the natural values of private responses into a dimensionless scale of desirability or preference. The function built is the basis for the formed approach to determining optimal and suboptimal solutions for minimizing the transmission of a financial crisis to the real economy. As a result of the study, it was determined that only 20 % of the options (25 decisions) of possible management ones can have a positive result. The formed block of decision support models is an important component of the developed integrated model, which allows modeling the process of the transmission of a financial crisis from the burst of a bubble in the financial sector to the impact on certain parts of the real economy.

Purpose. The article focuses on determining the rational parameters of data transmission interfaces for information and measuring system for testing the hydraulic transmissions, as well as determining the degree of fault to-lerance in various operating modes of the system. Methodology. In the study the researcher has determined and theoretically calculated the main characteristics of the data transmission channels from the hardware converters of the data signals of analog sensors of technological parameters to the computer. For a more complete assessment, an imitation model was created in the MATLAB environment to study the assigned task. Analysis of the results obtained from the theoretical calculations and using the simulation data model to determine the rational settings of interfaces (rational transmission speed, rational element base, rational system structure, etc.) of data transmission makes it possible to determine the rational characteristics of the system. Findings. For the existing information-measuring system for testing hydraulic locomotive transmission of diesel locomotives, studies were carried out to determine and theoretically calculate the main characteristics of the data transmission channels from the hardware converters of data signals from analog sensors of technological parameters to the computer. To study the tachometric subsystem, an imitation model was created that allowed to investigate the main characteristics of the data transmission channels from the hardware converters of data signals of analog sensors of tachometric parameters to the computer. The results of theoretical calculations were analyzed and the rational settings of the data transmission system were determined using the simulation model of data. Originality. The study to determine and theoretically calculate the main characteristics of the data transmission channels from the hardware converters of data signals of analog sensors of technological parameters to the computer showed that the system operates in the mode of actual «non-maintenance». For more detailed studies of the processes occurring in the transmission system of tachometric data, an imitation model was created in the Matlab environment. This model allowed carrying out a number of experiments. Practical value. On the basis of experiments with the model, rational ways of solving the existing problem of the system operation in the mode of actual «non-maintenance» were established. Also, the introduction of one of the proposed methods for solving the problem or combining them requires further research in the real system

Copyright of Technical Electrodynamics / Tekhnichna Elektrodynamika is the property of National Academy of Sciences of Ukraine, Institute of Electrodynamics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose. Determining the rational structure of the automatic control system of the motorcompressor, which provides minimal energy losses when switching on and going to a steady state mode of operation of a household refrigerator. Methodology. The methods of simulation modeling, comparative analysis, research of control systems and the main provisions of technical thermodynamics and the theory of automatic control are used in the work. Findings. The paper considers the principle of operation of the refrigeration unit of a household refrigerator, schematically shows its main elements and the relationship with the steam compression cycle. Simulation models of automatic control systems based on proportional-integral-differential controller, fuzzy and hybrid controllers have been developed. The proposed models allow to evaluate the quality of temperature control in the refrigeration compartment and to determine energy losses during transients. The results of computer simulation of transients in temperature control systems due to changes in the performance of the motor-compressor and the obtained values of power losses are presented. It is established that the smallest losses of the electric power at instant increase of heat inflows in refrigerating department occur at application of a fuzzy regulator. It is determined that the use of fuzzy controllers in automatic control systems reduces the duration of transients, the time of the first negotiation, the number of oscillations, but leads to static error and increases the maximum deviation from the set temperature in the refrigerator compartment. Originality. Simulation models of control systems of the motor-compressor of a household refrigerator for assessment of quality of regulation and definition of losses of the electric power during transient processes are developed. Practical value. The ways to increase the energy efficiency of household refrigerators through the introduction of control systems with fuzzy regulators are proposed. [ABSTRACT FROM AUTHOR]

Copyright of Financial & Credit Activity: Problems of Theory & Practice is the property of University of Banking of the National Bank of Ukraine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article is dedicated to the development of models for management of housing and communal services of a city on the basis of the system approach and simulation modeling. A review of the existing models of urban systems is carried out, their advantages and disadvantages are shown. With the use of the methods of simulation and scenario modeling, a simulation model for management of housing and communal services of a city has been developed, which makes it possible to predict the dynamics of the main socio-economic indicators of development of a city. On the basis of the model, the forecast indicators were simulated according to various scenarios for distributing financial resources for the renovation and maintenance of housing facilities of a city. The main criterion for effectiveness of the scenarios is the level of housing provision for the population. The models built can be used for making managerial decisions by local government authorities as well as in elaborating programs for the urban social and economic development.

There presented results of the research of existing scientific and methodological, and theoretical approaches to management of the socio-ecological-economic development of a region with subsequent definition of priorities of the regional policy taking into account the concepts of security and development. Based on the study of literature sources and the analysis of the available statistical base, the problem of assessing the level of social, economic, ecological development, the level of sustainable development and the degree of harmonization of sustainable development of territorial systems of a region is formulated, and a possible method of its solution is suggested. The direction and nature of the cause-effect relationships between social tension and the levels of economic, environmental, social development and the level of sustainable development of a region are determined. There proposed a scheme to build models for assessing the effectiveness of levers for managing social, economic and environmental processes at the level of territorial systems in a region, taking into account the level of social tension and indicators of the investment component of development.

An important trend in the theoretical study of the current activity and strategic prospects of small enterprises is the development of dynamic models of their functioning under the contemporary socio-economic conditions. The basis for building a simulation model of the logistic system of a small enterprise is the approach of J. Forrester developed by the author on the basis of the methods elaborated within the methodological approach to modeling the processes of development of the structure and properties of a small enterprise by building dynamic models. In the article a simulation model of the logistic system of a small enterprise has been elaborated, and on its basis there have been developed and substantiated the following elements of the logistics system of a small enterprise: a model of shipment management in a sales company; a model of management of a sales company; a production management scheme. The numerical calculations show that the total annual net profit increases if the demand increases at the beginning of the year.

The aim of the publication is to provide the results of the analysis of existing approaches to the formulation and solution of the problem of evaluating the level of efficiency of using investment, production and consumption components of the potential of the regional market for meat and meat products in the context of its territorial systems as well as development of an own scientific and methodological approach to evaluating and analyzing the linkages between the effectiveness of using the components of the regional market for this food type and its determining factors, based on the development and use of possibilities of applied econometric models. With regard to the available statistical base, taking into account the results of studying management of the food and investment components of economic security, namely the works aimed at determining the indicators of investment activity, investment attractiveness and efficiency of using the investment climate of the territorial systems of the region, the investment attractiveness of economic activities, and the consumer and production potentials of the regional market for meat and meat products, there carried out an appropriate analysis of the effectiveness of the factors facilitating the food component of regional development security based on the evaluation of the parameters of the simulative econometric models.

Пропонується імітаційна модель прийняття рішення з врахуванням оцінювання ефективності для підприємств хімічної промисловості, що забезпечує вибір та прийняття стратегічних рішень на основі оцінювання поточного стану підприємства, зокрема в галузі хімічної промисловості. В основі розробки даної моделі застосовано мультиагентний підхід. Зроблено висновки про можливість застосування даної моделі при розробці інформаційних систем управління підприємствами хімічної промисловості.

An improved version of the simulation model for forecasting scientific and technological development of economic activities in Ukraine has been developed within the framework of the research. The improved simulation model is fully consistent with the new classifier of economic activities in Ukraine, which was developed on the basis of the international statistical classification of economic activities by the European Union (NACE). Thus, it is possible to use the improved simulation model to predict the development of the industry, not only in Ukraine but also in any European Union country. To predict the process of production and distribution of products between economic activities, public sector, final consumption of the population, and foreign consumers the unit for modeling interbranch interactions has been integrated into the simulation model. Another developed unit allows modeling production volume of import for intra-consumption (production needs) for each of the considered in the simulation model economic activity. The improved structure of the simulation model gives the ability to predict the development of industry in Ukraine not only in the context of its main industries but also in the context of economic activities that form the industries.

Мета: Метою роботи є дослідження динаміки двигуна постійного струму послідовного збудження з імпульсним регулюванням частоти обертання і визначення можливості спрощення схеми електропривода. Методика: Методи імітаційного моделювання й аналітичні методи розрахунку та дослідження електромеханічних процесів в серієсному двигуні постійного струму при різних схемах імпульсного керування. Результати: Розроблено вдосконалену схему імпульсного регулювання двигуна постійного струму послідовного збудження. Для запропонованої і існуючої схем імпульсного регулювання розроблені моделі, за допомогою яких досліджені електромеханічні процеси тягового електроприводу в цих схемах і виконано їх порівняльний аналіз. Наведено результати дослідження модернізованої імпульсної схеми регулювання частоти обертання двигуна постійного струму в режимах розгону, вибігу і електродинамічного гальмування. Проведено аналіз величини пульсацій струму якоря та вплив на неї частоти комутації при використанні модернізованої схеми імпульсного регулювання. Наукова новизна: Розроблено нові імітаційні моделі, які дозволяють виконувати дослідження електромеханічних процесів тягового електроприводу при різних схемах імпульсного регулювання. Практична значимість: Розроблено вдосконалену схему імпульсного регулювання двигуна постійного струму послідовного збудження. Вдосконалено схему імпульсного регулювання двигуна постійного струму послідовного збудження за рахунок введення в схему імпульсного регулятора діода, який шунтує обмотку збудження, що дозволяє знизити швидкість загасання струму в обмотці збудження та використовувати режим електродинамічного гальмування при самозбудженні електродвигуна. Запропоноване схемне рішення дозволяє уникнути застосування додаткових незалежних джерел струму та спростити технічну реалізацію і зменшити витрати.

The article considers basic approaches to the development of simulation models, their advantages and disadvantages. The article outlines the simulation model for deep heat recovery process of steam-air mixtures with steam-compressor heat pump, including simulation models of the compressor, condenser, electronic expansion valve, evaporator, supercooler and contact heat exchanger recovering heat from steam-air mixtures. The simulation models of these components wereprepared using experimental data obtained by the authors as a result of performing physical field experiments at a laboratory test facility. The function of calculating the "ballast" and "effective" refrigerant flow is implemented in the simulation model of the heat pump evaporator.“Ballast” flow occurs due to the refrigerant supercooling to boiling point and is accompanied by partial evaporation of its share, which does not take part in the heat extraction by the evaporator. To do this, the evaporator simulation model was supplemented with a subsystem calculating the difference in boiling points (pressure) along the length of the evaporator based on the refrigerant flow rate and the evaporator temperature and taking into account the length of the evaporator segment where the liquid phase boils. Dependence of the pressure drop along the length of the evaporator on the refrigerant flow passing through it, is not a monotonically increasing function but is that having an extremum and decreasing at the refrigerant overheating levels ranging from 15 to 0 °C. Evaporator outlet pressure is calculated in the model using a nonlinear function of two variables - the position of EEV and the compressor’s rotational speed. The dynamic properties of the channels are modelledbased the links which transfer functions were obtained as a result of physical experiments. The adequacy of the simulation model was tested and a series of computer experiments were performed under conditions similar to those of the full-scale physical experiments at the laboratory facility. Comparison of simulation results and physical experiment showed a high degree of similarity. [ABSTRACT FROM AUTHOR]

Urgency of the research. The sphere of food provision of Ukraine represents a multidimensional space, the three sides of which the government-producer-consumer are constitute - the system triad. Systemic unity is explained by the integration of its components, since their stakeholders can play a simultaneously or sequentially double role in the market interaction process. This leads to a weakening of their interdependence, exacerbating the co-evolutionary imbalance of its constituents, which forms the preconditions for polarizing the interaction stakeholders of the market sides. Target setting. Reducing the density of economic ties between stakeholders reduces the sustainability of the food provision sphere, posing threats to food security. They are preceded by an imbalance of the stakeholders' economic interests, which necessitates the elaboration of a methodology for reconciling them. Actual scientific researches and issues analysis. Today, the opinions of scientists exploring the rationalization of market interaction are split in half. Some of them try to outline the conditions of optimal format of relations between market interactions' stakeholders in the, while others are focused on the design of harmonious markets. Uninvestigated parts of general matters defining. The results of scientific research are interpreted in the simulation or economic-mathematical models form. The research objective. To propose an algorithm for the synthesis of traditional methods with new knowledge and to construct of a harmonious food market dynamic model. The statement of basic materials. Given the macro-scale of scientific research, it is rational to combine optimization methods with simulation models. Cognitive maps should be built on the basis of multi-vector optimization, which will allow to establish causality of the economic processes and their effects. The whipping of the vector criterion into a global one should be supplemented with the simulation model Leebikh "barrel", which will make it possible to single out the most depressed ones. It is advisable to project a fair compromise on a systemic triad, combining it with the method of successive concessions. Conclusions. The algorithm of composing the scientific cognition methods allowed us to design a dynamic model of a harmonious market in the form of a triple integrated helix, capable of taking into account the co-evolution of its three sides. [ABSTRACT FROM AUTHOR]

The system analysis of the current conditions on the Labor Market in Ukraine shows the links between the main macroeconomic and other indicators, which characterize the state of the labor market. During the research, we developed the simulation model of demand and supply formation on the labor market in Ukraine. The scenario analysis, which was conducted on the basis of the model, showed the potential development prospects of the labor market development by different initial conditions and assumptions, and its impact on macroeconomic stabilization.

The basic structure of simulation model of the forwarding service process for motor transport has been given. Base classes and interfaces of the simulation model have been presented in order to develop suitable decision-making support software. It has been demonstrated that at the moment the simulation is the most acceptable option in forecasting the demand for freight forwarding services and interaction between agents at the transport service market.

High reliability and security of power unit are required during operation of power unit while maneuvering. They depend on the stability of reactor when transition from one power level to another. The axial offset is a quantitative measure of the reactor stability. It is shown that change of the active core inlet coolant temperature yields an uncontrollable disturbance affecting the axial offset and therefore the reactor stability. To insure the reactor stability the compromise-combined power control method is proposed. Analysis of the influence of temperature of coolant at the magnitude of the axial offset for different regulatory programs is carried out. The change in the depth of immersion of regulators in the active zone for different regulatory programs when the reactor plant daily capacity maneuver is studied.

Copyright of Technical Diagnostics & Nondestructive Testing / Tekhnicheskaya Diagnostika I Nerazrushayushchiy Kontrol is the property of International Association Welding (Paton Publishing House) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Machinery & Energetics is the property of National University of Life & Environmental Sciences of Ukraine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Ukrainian Scientific Journal of Information Security is the property of National Aviation University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Problems of Economy is the property of Research Centre for Industrial Developmen Problems of Nas and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Problems of Economy is the property of Research Centre for Industrial Developmen Problems of Nas and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose. Improvement of the universal motor control system for motor speed control using a feedback circuit with speed sensor and a microcontroller. Methodology. Computer simulation method using MATLAB (Simulink), Proteus, Arduino software were used. Findings. Improved control system for shown block diagram, which provides improved advanced motor control functions for a safe and quiet operation. These results were confirmed by a computer simulation model and tested on experimental stand. Originality. The dependences of the universal motor control process parameters of generating control signals using modern microcontroller Arduino were found. Practice value. Research stand for improved control system of universal motor food processor were designed and developed, which can be used to diagnose and repair electrical appliances. [ABSTRACT FROM AUTHOR]