bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of a method for geometric modeling of centrifugal compressor impellers
Authors: Borisenko Valeriy , Ustenko Serhiy , Ustenko Iryna , Kuzma Kateryna
Published: March 2021

The practice of designing centrifugal compressors in which impellers are the main components shows that there are reserves for their further improvement. One of the main reserves consists in improving flow conditions for the compressed medium in the compressor setting and, above all, in the impeller. A method of geometric modeling settings of the impellers of centrifugal compressors was proposed which involves the construction of meridional boundaries of impellers and the blade profile on an involute of the cylindrical surface of the outer radius of the impeller. The blade is represented by ruled surfaces. The outer boundary of the impeller is described by a curve in natural parameterization using cubic dependence of curvature on the arc length. Dependences and length of the arc are determined in the process of modeling the boundary based on the set source data. The problem is solved by minimizing deviations of intermediate curves from the boundary endpoint. The inner boundary is obtained as an envelope of circles inscribed in the meridional channel of the impeller. Radii of the circles are determined taking into account the flow areas of the channel. The midline of the blade profile on an involute of the cylindrical surface of the outer radius of the impeller is modeled using a curve that is presented in natural parameterization with quadratic law of curvature distribution. A computer code was developed in the Fortran Power Station programming environment that visualizes the obtained numerical results graphically on a computer display in addition to digital information on the modeled boundaries and the blade profile. Graphical results were presented. They confirmed the efficiency of the proposed method of modeling the settings of centrifugal compressor impellers. The method can be useful to offices involved in the design of centrifugal compressors
Establishing the effect of a simultaneous reduction in the filling load inside a chamber and in the content of the crushed material on the energy intensity of self-oscillatory grinding in a tumbling mill
Authors: Deineka Kateryna , Naumenko Yuriy
Published: March 2021

The effect of a simultaneous change in the degree of filling a chamber with load κbr and in the content of the crushed material κmbgr on the efficiency of the self-oscillatory grinding process has been estimated.
Using a method of numerical modeling based on the results of experimental visualization of the flow has helped establish an emergent dynamic effect of the sharp increase in the self-oscillatory action of two-faction loading at a joint reduction in κbr and κmbgr. A significant decrease in the passive quasi-solid loading motion zone has been detected, as well as an increase in the active pulsation zone and a growth of dilatancy. The manifestation of the effect is enhanced by the simultaneous interaction of increasing the scope of self-oscillations and weakening the coherent properties of particles in a loose large fraction under the influence of the particles of fine fraction. A significant decrease in the values of the inertial loading parameters has been established: maximum dilatancy υmax, the relative scale of self-oscillations ψRυ, the maximum share of the active part of κfammax, and the generalized complex degree of dynamic activation Ka. A 2.65-time growth of υmax was detected, ψRυ increased by 5 times, κfammax ‒ by 4.36 times, Ka ‒ by 18.4 times, at a joint decrease in κbr from 0.45 to 0.25, in κmbgr ‒ from 1 to 0.
The synergistic technological effect of a sharp decrease in the specific energy intensity Еo/Еs has been established, as well as an increase in the relative performance Co/Cs in the self-oscillatory grinding, due to a significant increase in the dynamic action of loading, which is exacerbated by the joint interaction of reduced κbr and κmbgr.
The process of the self-oscillatory grinding of cement clinker has been investigated. A 62 % reduction in Еo/Еs and a 125 % increase in Co/Cs were detected at a joint decrease in κbr from 0.45 to 0.25, in κmbgr ‒ from 1 to 0.125.
The established effects make it possible to substantiate the parameters for the energy-efficient self-oscillatory process of grinding in tumbling mills with a conventional structure
Determining the kinetic and energy parameters for a combined technique of drying apple raw materials using direct electric heating
Authors: Savoiskyi Oleksandr , Yakovliev Valerii , Sirenko Viktor
Published: March 2021

The development of technology and drying equipment tackles a triune task: to intensify drying processes, to save energy, to ensure that proper product quality is achieved. This issue is resolved by modern advancements by supplying thermal energy throughout the entire sample volume. The simplest option among the known techniques is to heat wet raw materials by passing an electric current directly, with an external blowing by a hot heat carrier.
This paper reports an experimental study of the combined process of drying apple raw materials using direct electric heating.
The influence of control factors such as the field intensity and a heat carrier temperature on the kinetic parameters of the process has been determined, namely: the duration of the combined drying of apples, the rate of moisture removal, and a change in the temperature of the sample.
It was established that the application of additional electric heating with an electric field intensity of 20–40 V/cm during convective drying with a heat carrier temperature of 25–55 °C reduces the duration of apple dehydration by 3‒5 times.
Permissible limits for changing the combinations of basic technological parameters have been determined, as well as the rational modes for treating raw materials in order to ensure the predefined quality of finished products. Such combinations of technological parameters of heating, in particular the intensity of the electric field and air in the dryer, are 30 V/cm+40 °C, and 25 V/cm+55 °C.
The energy parameters of the proposed combined technique of drying apple raw materials have been determined. It was established that the specific energy consumption for the removal of 1 kg of moisture at direct electric heating is 2,350–2,400 kJ/kg (0.66 kWh/kg).
The study performed could provide a prerequisite for devising an energy-efficient technique for the combined drying of fruit and vegetable raw materials using direct electric heating
Development of technology for macaroni products based on flour of grain crops and ion-zoned water
Authors: Baiysbayeva Meruyet , Iskakova Galiya , Izembayeva Assel , Batyrbayeva Nurgul , Dikhanbayeva Fatima , Daribayeva Gulnur
Published: March 2021

The nutritional value of food is one of the most important factors that determine the health of the population. In the macaroni market, dietary and functional products, fortified macaroni products and products of high nutritional value occupy a small segment that does not exceed 1 %. In this regard, the development of an assortment of pasta with increased nutritional value, with a directionally changed chemical composition, is relevant. In the pasta industry, an increase in the nutritional and biological value of products is achieved through the introduction of non-traditional types of raw materials and special food additives into the recipe. To reduce the deteriorating effect of corn and amaranth flour on the pasta properties of flour from durum wheat, ionized water was used with a concentration of ions of 1,000, 2,000, 3,000, 4,000 units/cm3 and ozone of 2 mg/l. It was found that ionized water has a positive effect on the properties of gluten and the quality of pasta with the addition of corn and amaranth flour. It was determined that the best quality of pasta is achieved when using ionized water with an ion concentration of 3,000 units/cm3 and ozone 2 mg/l and at dosages of amaranth flour 17.5 %, corn flour – 20 % to pasta flour. Summing up the results of the experimental study, the amount of prescription components for the production of pasta with high nutritional and biological value was optimized
Effect of microbial polysaccharides on the quality indicators of protein-free and gluten-free products during storage
Authors: Samokhvalova Olga , Kucheruk Zinoviya , Kasabova Kateryna , Oliinyk Svitlana , Shmatchenko Nataliа
Published: March 2021

This paper reports a study into the effect of the microbial polysaccharides (MPS) xampan, enposan, and gelan on quality indicators during the storage of protein-free bread and gluten-free muffins.
Microbial polysaccharides such as xampan, enposan, and gelan are effective structure-forming agents in gluten-free products. These hydrocolloids not only participate in the formation of the structure of dough and finished products but also affect the staling processes in gluten-free products during storage.
The addition of the studied MPS leads to a slowdown in the staling processes of protein-free bread based on corn starch, as well as muffins based on wheat germ meal, during storage. It was found that in 24 hours of storage, the protein-free bread demonstrates a decrease in the moisture loss and crumbling index, as well as an increase in compressibility indicator, compared with control samples. It was also determined that gluten-free muffins with the addition of MPS lose moisture more slowly over 7 days of storage; they have lower crumbling and compressibility indices compared to the control. This is due to the high hydrophilic properties of the studied microbial polysaccharides, which can bind a significant amount of water and retain it during the storage of products. In addition, microbial hydrocolloids can envelop the gelatinized starch grains with a thin film, thereby helping inhibit the process of starch retrogradation.
The samples of bread and muffins containing MPS almost did not change their appearance, color, taste, and smell during the studied shelf life, while the crumb of the examined samples demonstrated better elasticity and less crumbling.
All studied MPS exhibit the same nature of the effect on the quality indicators of products during storage with xampan exerting the greatest effect and gelan ‒ the least
Determining stresses in the metallic structure of an overhead crane when using running wheels of the new design
Authors: Fidrovska Nataliia , Slepuzhnikov Evgen , Varchenko Ivan , Harbuz Serhii , Shevchenko Serhii , Chyrkina Maryna , Nesterenko Viktoriia
Published: March 2021

This paper proposes a method to experimentally study the stressed state of the metallic structure of an overhead crane when using running wheels of different designs. The study employed a functioning electric, supporting, double-girder overhead crane with a capacity of 5 tons and a run of 22.5 m. Strain gauges assembled in a semi-bridge circuit and connected to the analog-digital converter Zetlab210 (Russia) were used to determine the girder deformations at the time of hoisting and moving cargoes of different masses. The cargo was lifted and displaced under the same conditions, on the regular wheels of a cargo trolley and the wheels with an elastic rubber insert. The girder deformation diagrams were constructed. The subsequent recalculation produced the stressed state's dependences at each point of cargo movement when using both regular wheels and the wheels with an elastic rubber insert. Also established were the dependences and the duration of oscillations that occur over the cycle of cargo lifting and moving. The experimental study cycle included cargo lifting in the far-left position by a trolley, moving the cargo to the far-right position, and returning the trolley with the cargo to its original position.
It should be noted that the application of a new, modernized design of the running wheels of a cargo trolley with an elastic rubber insert effectively dampen the oscillations in the metallic structure of the crane.
The experimental study's results helped establish an 18 % reduction in stresses in the girder of the overhead crane, as well as a decrease in peak vibrations, by 20 seconds, at the same cycles of cargo hoisting and moving. In addition, using wheels with an elastic rubber insert reduces the period of oscillation damping at the end of the cycle of cargo movement, by at least 30 %.
Devising a method to analyze the current state of the manipulator workspace
Authors: Ashhepkova Natalja
Published: March 2021

This paper has proposed a program analysis method over the current state of the workspace of an anthropomorphic manipulator using the Mathcad software application package (USA). The analysis of the manipulator workspace helped solve the following sub-tasks: to calculate the limits of the grip reach, to determine the presence of "dead zones" within the manipulator workspace, to build the boundaries of the manipulator workspace. A kinematic scheme of the manipulator typically provides for at least five degrees of mobility, which is why in the three-dimensional Cartesian coordinate system the work zone boundaries represent the surfaces of a complex geometric shape. The author-devised method makes it possible to construct the projections of the boundaries of the manipulator's work zone onto the coordinate planes in the frame of reference associated with the base of the robot.
Using Mathcad's built-in features makes it possible to effectively solve the above sub-tasks without wasting time developing specialized software. The Mathcad software application package provides for the possibility of a symbolic solution to the first problem of the kinematics of an industrial robot, that is, the program generates analytical dependences of the coordinates for special point P (pole) of the grip on the trigonometrical functions of the generalized coordinates. The resulting analytical dependences are used for kinematic and dynamic analysis of the manipulator.
Special features in constructing mathematical models when using the Mathcad software application package have been revealed. Simulating the manipulator movement taking into consideration constraints for kinematic pairs, the drives' power, as well as friction factors, makes it possible to optimize the parameters of the manipulator kinematic scheme.
An example of the analysis of the working space of an anthropomorphic manipulator with five degrees of mobility has been considered.
The reported results could be used during the design, implementation, modernization, and operation of manipulators.
Processing of ethanol-containing waste of oil neutralization in the technology of hand cleaning paste
Authors: Petik Ihor , Belinska Anna , Kunitsia Ekaterina , Bochkarev Sergiy , Ovsiannikova Tetiana , Kalyna Viktoriia , Chernukha Anton , Ostapov Kostiantyn , Grigorenko Natalia , Petukhova Olena
Published: March 2021

The graphical dependence of the washing capacity of ethanol-containing soapstock on the concentration in an aqueous solution and the temperature of interaction with the polluted material has been determined. It is proposed to use a 40 % aqueous solution of ethanol-containing soapstock in the hand cleaning paste technology. This soapstock solution has a washing capacity of 92–98 % at the temperature of interaction with the polluted material of 25–40 °C.
The regularity of the effect of the structurant content on the consistency of hand cleaning paste was investigated using an approximating polynomial. This made it possible to substantiate the effective concentration of carboxymethyl cellulose (0.4...0.6 %) and cetysltearyl alcohol (1.8...2.0 %) in the formulation. The obtained regression equation is useful for adjusting the content of structurants in the formulation, depending on the consumer's requirements for the viscosity of the developed detergent.
A comparison of the quality indicators of the developed hand cleaning paste based on ethanol-containing soapstock with a sample of similar “Primaterra Automotive” commercial hand cleaning paste was carried out. The quality indicators of the developed paste are as follows: effective viscosity at 20...22 °С – 32.0 Pa∙s; foaming capacity – 23 mm, foam stability – 62.0 %; washing ability – 92.0 %. It was determined that these quality indicators do not differ significantly in the developed detergent and commercial analogue. The data obtained indicate the prospects of processing ethanol-containing soapstock into the hand cleaning paste based on natural surfactants. The developed detergent due to the content of ethanol, glycerin and hydrogen peroxide has antiseptic properties, which is a competitive advantage among analogues. Such utilization of ethanol-containing soapstock makes the process of oil neutralization environmentally safe and economically viable
Determining the influence of transformation changes in the life cycle on the assessment of effectiveness of an ecologistic system project
Authors: Rudenko Sergey , Gogunskii Viktor , Kovtun Tetiana , Smrkovska Victoriya
Published: March 2021

The issue of assessing the effectiveness of a project of an ecologistic system using the criterion of «a discounted payback period», which takes into consideration the transformational changes in the project life cycle, was considered.
The specific features of the life cycle of a project of an ecologistic system, in the structure of which it is proposed to include environmentally-oriented regeneration and revitalization phases, were explored. The phases of a life cycle were divided into stages, between which consecutive and parallel relations were established. The project life cycle consists of time intervals, during which from one to three stages of the project phases can run in parallel. A model of the life cycle of an ecologistic system, which shows the relations between time intervals and cash flows that correspond to the stages of the project life cycle phases, was developed. A mathematical formula for calculating the discounted payback period of a project, which takes into consideration the specific features of the formation of cash flows of separate phases of the life cycle of an ecologistic system, was proposed. The application of the formula is possible when assuming the constancy of cash flows of the stages of operational and the regeneration phases, which corresponds to the conditions of uncertainty of their forecasting at the beginning of the project. The functional dependences between the discounted payback period and cash flows during the phases of a project life cycle were studied.
Depending on a phase of the life cycle, the dependence is expressed by a linear, polynomial, or power function. The identification of functional dependences makes it possible to study the dynamics of changes in the discounted payback period with changes in project cash flows, which can be used in forecasting the effectiveness of an ecologistic system project.
Design of a combined burner based on the patterns of interaction between an external swirling jet and an axial direct-flow jet
Authors: Klymchuk Oleksandr , Denysova Alla , Zaitsev Nikita , Lozheczhnikova Nadija , Borysenko Krystyna
Published: March 2021

The issue of providing fuel and energy resources to the population depends to a large extent on the wear of thermal networks, as well as heat-generating equipment, which, accordingly, forces the consumer to abandon the centralized heating supply in favor of decentralized supply. However, low-power heat-generating units for autonomous consumers do not most of the time operate under the rated mode.
The most promising way to solve the issue of energy conservation is to improve the utilization rate of fuel and energy resources in heat-generating units for decentralized heating systems that operate under non-stationary regimes.
An experimental study of the velocity field of interaction between the coaxial axial direct-flow and external swirling jets has established that the performance efficiency of a heat-generating plant at a change in the thermal load could be improved by controlling the resulting velocity field. For a more even distribution of temperature within the furnace volume, it has been proposed to supply fuel with an oxidizer in the furnace by the axial direct-flow and swirling coaxial jets.
It was revealed that at a distance of 2 diameters of the axial branch pipe from the cut there occurs a transverse toroidal vortex. The appearance of such a vortex is explained by the emergence of low-pressure regions due to the different angles of opening of the swirling outer jet and axial direct-flow jet. The considered dependence of change in the gas flow rate at a decrease in power has demonstrated that the gas flow rate in the proposed burner is less than that in analogs (vortex burner or direct-flow burner) by 10‒15 % when the power of the burner is reduced. At the same time, the specified advantage is limited to the range of the burner's power of 50‒130 kW.
The results reported confirm the possibility of controlling the velocity field and temperature distribution when the total fuel and oxidizer flow rate changes within the operational range of low-power heat-generating plants. The correspondence between the temperature field and the velocity field in the interaction of non-isothermal jets has also been shown
Developing e-maturity model for municipal project and program management system
Authors: Fesenko Galyna , Fesenko Tetiana , Fesenko Hryhorii , Shakhov Anatoliy , Yakunin Anatolii , Korzhenko Volodymyr
Published: March 2021

The role and importance of information and communication technologies (ICT) in city management are analyzed. It is substantiated that the digital component of municipal management is an important element of a sustainable city and ensures the expansion of citizens’ access to basic services. Modeling the assessment of the electronic maturity of the management office of municipal digitalization projects is considered through the prism of the technological maturity model of I. Kendall and K. Rollins. A matrix for assessing the electronic maturity of municipal e-projects, represented by project management knowledge areas and digital ICT characteristics of electronic maturity, has been developed.
The results of digital maturity modeling are discussed on the example of the Municipal e-Project Management Office (PMOеМ). Eight levels of PMOеМ maturity are proposed: «I – PMOеМ is able to effectively implement information service projects»; «II – PMOеМ analyzes the organizational aspects of the online services of the municipality»; «III – PMOеМ develops ways to effectively implement online services»; «IV – PMOеМ requires a high level of e-government maturity, opening «fast access» of citizens to e-services»; «V – municipality staff as members of the project team (PMOеМ) ensures the progress of functional efficiency of city smart services»; «VI – PMOеМ is able to provide the vast majority of municipal services using ICT tools»; «VII – PMOеМ provides an expanded range of smart services»; «VIII – all municipal services are provided under the maximum mainstreaming of ICT». The proposed assessment tool will allow the PMOеМ directorate and the top management of IT organizations to conduct a self-assessment of progress in the digital management of municipal e-projects, e-programs and select the actions necessary to move to a higher level of e-maturity.
Developing an algorithm to minimize boolean functions for the visual-matrix form of the analytical method
Authors: Solomko Mykhailo
Published: March 2021

This research has established the possibility of improving the effectiveness of the visual-matrix form of the analytical Boolean function minimization method by identifying reserves in a more complex algorithm for the operations of logical absorption and super-gluing the variables in terms of logical functions.
An improvement in the efficiency of the Boolean function minimization procedure was also established, due to selecting, according to the predefined criteria, the optimal stack of logical operations for the first and second binary matrices of Boolean functions. When combining a sequence of logical operations using different techniques for gluing variables such as simple gluing and super-gluing, there are a small number of cases when function minimization is more effective if an operation of simply gluing the variables is first applied to the first matrix. Thus, a short analysis is required for the primary application of operations in the first binary matrix. That ensures the proper minimization efficiency regarding the earlier unaccounted-for variants for simplifying the Boolean functions by the visual-matrix form of the analytical method. For a series of cases, the choice of the optimal stack is also necessary for the second binary matrix.
The experimental study has confirmed that the visual-matrix form of the analytical method, whose special feature is the use of 2-(n, b)-design and 2-(n, x/b)-design systems in the first matrix, improves the process efficiency, as well as the reliability of the result of Boolean function minimization. This simplifies the procedure of searching for a minimal function. Compared to analogs, that makes it possible to improve the productivity of the Boolean function minimization process by 100‒200 %.
There is reason to assert the possibility of improving the efficiency of the Boolean function minimization process by the visual-matrix form of the analytical method, through the use of more complex logical operations of absorbing and super-gluing the variables. Also, by optimally combining the sequence of logical operations of super-gluing the variables and simply gluing the variables, based on the selection, according to the established criteria, of the stack of logical operations in the first binary matrix of the assigned function
An analysis of tube thickness effect on shell and tube heat exchanger
Authors: Krisdiyanto Krisdiyanto , Adi Rahmad Kuncoro , Sudarisman Sudarisman , Hamdan Sinin Bin
Published: March 2021

Heat exchangers are important equipment for the process of placing heat. The most widely used type of heat exchanger is shell and tube. This type is widely used because of its simple and easy design. Design of shell and tube heat exchangers is done by the side or shell variations to get the desired performance. Therefore, research is conducted to study the effect of tube thickness on heat transfer, pressure drop, and stress that occurs in the shell and tube heat exchanger so that the optimal tube thickness is obtained.
In this research, the activities carried out are the design of heat exchangers for the production of oxygen with a capacity of 30 tons/day. The standard used in this study is the 9th edition heat exchanger design guidance document compiled by the Tubular Exchanger Manufacturer Association (TEMA). Analysis of the tube thickness effect on heat transfer, pressure drop, and stress was carried out using the SimScale platform.
The effect of variations in tube thickness on heat transfer is that the thicker the tube, the lower the heat transfer effectiveness. The highest value of the heat exchanger effectiveness is 0.969 at the tube thickness variation of 0.5 mm. The lowest value of the heat exchanger effectiveness is 0.931 at the tube thickness variation of 1.5 mm. The effect of variations in tube thickness on pressure drop is that the thicker the tube, the higher the pressure drop. The highest value of pressure drop is in the variation in tube thickness of 1.5 mm, 321 Pa. The lowest value of drop pressure is in the variation of 0.5 mm tube thickness, which is 203 Pa. The thickness of the tube also increases the maximum stress on the components of the shell, head, tubesheet, baffle, and saddle, but the value is fluctuating
Development of a method for constructing linguistic standards for multi-criteria assessment of honeypot efficiency
Authors: Korchenko Anna , Breslavskyi Vladyslav , Yevseiev Serhii , Zhumangalieva Nazym , Zvarych Anatolii , Kazmirchuk Svitlana , Kurchenko Oleg , Laptiev Oleksandr , Sievierinov Оleksand , Tkachuk Sirhii
Published: March 2021

One of the pressing areas that is developing in the field of information security is associated with the use of Honeypots (virtual decoys, online traps), and the selection of criteria for determining the most effective Honeypots and their further classification is an urgent task. The main products that implement virtual decoy technologies are presented. They are often used to study the behavior, approaches and methods that an unauthorized party uses to gain unauthorized access to information system resources. Online hooks can simulate any resource, but more often they look like real production servers and workstations. A number of fairly effective developments are known that are used to solve the problems of detecting attacks on information system resources, which are based on the apparatus of fuzzy sets. They showed the effectiveness of the appropriate mathematical apparatus, the use of which, for example, to formalize the approach to the formation of a set of reference values that will improve the process of determining the most effective Honeypots. For this purpose, many characteristics have been formed (installation and configuration process, usage and support process, data collection, logging level, simulation level, interaction level) that determine the properties of online traps. These characteristics became the basis for developing a method for the formation of standards of linguistic variables for further selection of the most effective Honeypots. The method is based on the formation of a Honeypots set, subsets of characteristics and identifier values of linguistic estimates of the Honeypot characteristics, a base and derived frequency matrix, as well as on the construction of fuzzy terms and reference fuzzy numbers with their visualization. This will allow classifying and selecting the most effective virtual baits in the future.
Improvement of methods for assessing the effectiveness of dedicated lanes for public transport
Authors: Fornalchyk Yevhen , Vikovych Ihor , Royko Yurii , Hrytsun Oleh
Published: March 2021

There are different configurations of street and road networks in cities, which is why those transportation models that determine how effectively a public transport network is operated are different. Along with this, some transport areas may have characteristic features predetermined by the density of a street network, the intensity of individual and public traffic. The special feature of the current study is determining the operational effectiveness of dedicated lanes for public transport given a significant density of the main street and road network. Significant density is characterized by its value for the distance between adjacent intersections in the range of 150‒200 m. With such planning patterns, there is a mutual influence of the conditions of individual and public transport between adjacent intersections. An increase in the distance between intersections disrupts the stability of traffic flow through its disintegration into separate groups based on the dynamic characteristics of vehicles.
A characteristic feature of the proposed procedure for evaluating the operational effectiveness of dedicated lanes is that the use of a GPS monitoring system makes it possible to relatively quickly determine the areas of the network where there are the greatest delays in movement in real time. After that, attention is focused on investigating the main factors of influence and their parameters followed by modeling.
The reported results would in the future contribute to devising a clear sequence of transport-related research based on a set of their methods in order to acquire representative data and define adequate patterns. An important practical result is the use of not only established normative approaches to the design of dedicated lanes, which are common for all types of street and road networks but taking into consideration the peculiarities characteristic of their individual sections.
Improving the designing of marine tethered systems using the principles of shipbuilding 4.0
Authors: Blintsov Volodymyr , Trunin Kostiantyn
Published: March 2021

This paper considers the issues and theoretical aspects related to improving the design of maritime tethered systems (MTSs) with flexible links (FLs) using underwater towed systems (UTSs) as an example. That allows them to be used in the early stages of design by implementing the principles of Shipbuilding 4.0 and BIM technologies. Such regimes have not previously been described by existing mathematical models (MMs). The expected result of the current study is a significant decrease in the cost of different resources. At the same time, the basic reliable results of design solutions could be obtained already in the early stages of design.
The theoretical basis of the proposed method for improving the design of MTS with FL is the improved design concept (IDC) for MTS with FL while the tool base of the method is a special modeling complex (SMC). The use of IDC along with SMC at the research (pre-prototype) design phase reduces the number of MTS design stages.
The proposed method to improve the design of MTS with FL, based on the MM that notates the dynamics of MTS FL and MTS with FL, makes it possible to investigate different modes of operation of almost all MTS classes. That allows devising the recommendations for predicting possible operational loads in order to design their elements. At the same time, there is an opportunity to improve the existing methods for calculating and designing MTS with FL with the required properties and parameters, and to bring them to the level of engineering application.
The application of SMC at the pre-prototype design stage makes it possible to avoid the use of physical modeling of the operational regimes of MTS with FL associated with the full-scale testing on the high seas
The synthesis of control system to synchronize ship generator assemblies
Authors: Budashko Vitalii , Shevchenko Valerii
Published: March 2021

This paper considers the construction of principles and the synthesis of a system of effective control over the processes of synchronization of generator sets (GSs) that form a part of the distributed MP-control systems for complex ship technical systems and complexes (STS and C). The tasks of synchronization have been set, the process and database models have been built, the system configurations have been defined. Based on the use of resultant functions, we have determined stages in solving the tasks of control over the frequency adjustment synchronization in a hierarchical sequence. The performance analysis of the STS and C control elements has been carried out; the use of the integrated optimization criteria and dual management principles has been proposed. Practical techniques to manage the GS synchronization have been given. We have solved the problem of high-speed control over the frequency of synchronized objects based on the principles of adjustment. That has made it possible to determine in advance the moments of GS enabling under the deterministic and stochastic statement of the synchronization task. The results of the experimental study into the GS synchronization processes are given; the effectiveness of the proposed GS control has been proven. The principles underlying the construction of procedures to control the GS composition when using the methods of "rigid" and "flexible" thresholds have made it possible to define the optimization criteria and implement a control law that satisfied the condition for an extremum, which is an indicator of the feasibility of the set goal and takes into consideration the limitations of control influences. We managed to design a system in the class of adaptive control systems by the appropriate decomposition of the system's elements by splitting a synchronization task into the task on performance and the task on control under the required conditions. The given examples of the processes where the synchronization failed while using standard synchronizer control algorithms, as well as processes of successful GS synchronization when applying the proposed synchronizer dual control algorithms, have confirmed the reliability of the main scientific results reported here.
Development of conceptual provisions to effectively manage the activities of a multimodal transport operator
Authors: Sokolova Olena , Soloviova Olena , Borets Irina , Vysotska Irina
Published: March 2021

Modern market requirements for transportation of cargo flows according to the «quality, speed, and cost» criteria were studied. It was found that multimodal routes have the lowest delivery time, high reliability, and minimum transit time, which provides a more accurate level of control of costs, traffic schedules, and transport safety. It was determined that the effectiveness of multimodal transportation schemes depends on a degree of realization of resource capabilities and management technologies of a multimodal transport operator (MTO).
The functional features and the MTO classification were generalized, which makes it possible to generate the MTO business model as a responsible integrator of transport and logistic processes, rather than consider it only from the point of view of the organizer of mixed transportation schemes.
The technology of the organizational transportation process was systematized, based on which a system of strategic goals and key performance indicators (KPI) was developed, which makes it possible to determine the «bottlenecks» according to the main business processes of a multimodal transportation operator.
The modified multifactor DuPont model was proposed, which makes it possible to establish the priority of factor evaluation of more time-stable indicators based on determining the levers of the MTO resource efficiency with greater coverage of factors.
The performed research can become the basis for further development of the multimodal cargo transportation system based on the development of the model for optimal management of the MTO business processes.
Estimation of state financial support for non-priority territorial units using the example of bridge construction
Authors: Levchenko Iaroslava , Britchenko Igor
Published: March 2021

The article discloses the problem of distributing state financial support based on an integrated approach. The study has proved the urgency and necessity of state support for the lowest priority territorial units (regions). It answers the research question of what components need to be included in the methodology for determining state financial support. A comprehensive method for estimating the share of public funds is proposed, taking into account the investment attractiveness of a region (oblast) and the risk of the corresponding region (oblast). To achieve this goal, the following general scientific and special methods and research techniques were used in the work, such as comparative analysis of scientific literature and information sources based on methods of comparison, systematization, and generalization; generalization of the analysis results, as well as logical generation of conclusions and integral assessment.
Since the problem of financing the construction and reconstruction of bridges is relevant for a number of countries, this technique was tested using an example of bridge construction.
According to the obtained results, territorial units (regions) that are not leaders in priority for the investor and have a high level of riskiness of investing financial resources become eligible for state financial support. The problem of financing such regions can be solved only through state support. The results of calculations show that the distribution of financial resources with the available volume of public finances K=1 allocated for support is carried out proportionally. An integrated approach made it possible to identify 10 territorial units (oblasts) for funding, with the oblasts with the worst priority factors receiving the largest share of state financial support.
This study is of practical interest to government agencies in the distribution of public funds, and it is of theoretical importance to researchers dealing with issues of financial security and public administration
Estimating parameters of linear regression with an exponential power distribution of errors by using a polynomial maximization method
Authors: Zabolotnii Serhii , Khotunov Vladyslav , Chepynoha Anatolii , Tkachenko Olexandr
Published: March 2021

This paper considers the application of a method for maximizing polynomials in order to find estimates of the parameters of a multifactorial linear regression provided the random errors of the regression model follow an exponential power distribution. The method used is conceptually close to a maximum likelihood method because it is based on the maximization of selective statistics in the neighborhood of the true values of the evaluated parameters. However, in contrast to the classical parametric approach, it employs a partial probabilistic description in the form of a limited number of statistics of higher orders.
The adaptive algorithm of statistical estimation has been synthesized, which takes into consideration the properties of regression residues and makes it possible to find refined values for the estimates of the parameters of a linear multifactorial regression using the numerical Newton-Rafson iterative procedure. Based on the apparatus of the quantity of extracted information, the analytical expressions have been derived that make it possible to analyze the theoretical accuracy (asymptotic variances) of estimates for the method of maximizing polynomials depending on the magnitude of the exponential power distribution parameters.
Statistical modeling was employed to perform a comparative analysis of the variance of estimates obtained using the method of maximizing polynomials with the accuracy of classical methods: the least squares and maximum likelihood. Regions of the greatest efficiency for each studied method have been constructed, depending on the magnitude of the parameter of the form of exponential power distribution and sample size. It has been shown that estimates from the polynomial maximization method may demonstrate a much lower variance compared to the estimates from a least-square method. And, in some cases (for flat-topped distributions and in the absence of a priori information), may exceed the estimates from the maximum likelihood method in terms of accuracy
Creating the agile-model to manage the activities of project-oriented transport companies
Authors: Pavlova Nataliia , Onyshсhenko Svitlana , Obronova Alesia , Chebanova Tetiana , Andriievska Vira
Published: March 2021

This study considers an agile model for the organization of activities of a project-oriented transport company.
Building a project-oriented company (project-oriented management) requires an appropriate theoretical base. The agile model of transport company operation has been developed, for which the cycles have been determined, the content of each cycle has been defined, and the flow of information has been simulated. The transformation of information in each cycle of the model has been characterized, taking into consideration the operational specificity of transport companies’ activities. A given model was compared to the main stages of a project’s lifecycle. Two indicators have been proposed such as the degree of project uniqueness and the degree of project complexity that reflect the corresponding project characteristics. The complexity of the project’s operational activities refers to the number of elements and their alternatives. Part of the project is an «operation» that forms a unit of the project’s network schedule. The uniqueness of the project of operational activities means the difference between the current project and other projects, already implemented or is being implemented by the company. The estimation formulae for these indicators have been derived. The proposed indicators for the given example have been calculated; the interpretation of the results has been proposed. The calculation results have demonstrated the adequacy of input-output data and the practical applicability of these indicators. These metrics are not limited to the context of an additional project specification. Their level is proposed to be used in the processes of estimating the time of individual project periods and the agile model’s cycles within the initial stage ‒ creating a product concept model and preparing for implementation. In addition, these indicators could be used effectively for employee remuneration.
Development of a method for obtaining a CdS/CdTe/Cu/Au module on a flexible substrate designed for backup supplying systems prevention of emergency situations
Authors: Deyneko Natalia , Yeremenko Sergey , Kamyshentsev Gennady , Kryvulkin Igor , Matiushenko Mykola , Myroshnyk Oleg , Pruskyi Andrei , Soshinsky Alexander , Strelets Victor , Shevchenko Roman
Published: March 2021

The study of methods for obtaining base layers of cadmium telluride for the creation of efficient solar cells on a flexible substrate, intended for backup power supply of security systems and facility control. Considering that the polyamide film is stable up to a temperature of 450 °С, the formation of the base layers of solar cells based on cadmium telluride on flexible polyamide substrates was carried out by the method of DC magnetron sputtering. Using the chosen method, experimental samples of micromodules on a flexible substrate with series-connected solar cells based on CdS/CdTe/Cu/Au were obtained. To understand the effect of the failure of one or more solar cells on the efficiency of the entire micromodule during operation, an analysis of the initial parameters and light diode characteristics of individual solar cells of micromodules was carried out. The design of the micromodules, in which the solar cells were connected in series, made it possible to separately measure their output parameters. It was found that the creation of a Cu/Au rear tunnel contact made it possible to obtain high values of the output parameters for individual solar cells, but the micromodule contains a limitation by a shunted solar cell. However, the greatest role in reducing the efficiency of the entire micromodule is played by ineffective absorption of radiation when passing through the polyamide film, which led to a decrease in the efficiency of the entire micromodule, in which there is a shunted element, to 3.9 %. The maximum efficiency of the obtained samples of micromodules was 5.3 %