Pub Date : 2023-08-01DOI: 10.33271/nvngu/2023-4/074
V. Hovorukha, A. Hovorukha
Purpose. Enhancement of the performance, service life and sustainability of industrial vehicles, mining machinery and various equipment by reducing the friction coefficient. Methodology. Laboratory research on assessing the interaction of friction pairs under external loading, rolling, and sliding in dry friction conditions, as well as the influence of friction modifiers. Industrial experimental studies on the performance indicators of mining machinery under the influence of friction modifiers. Findings. Actual diagrams depicting changes in the friction coefficient between the contacting surfaces of disc pairs were obtained for four specific loading periods and corresponding pressures of 529, 374, 274 and 187 MPa. These measurements were taken while the discs experienced a 10 % relative slippage and cyclic load interaction during the testing of specimens, with the presence of the repair-recovery compound called “Ideal” and without it, using only dry friction. The new technologies and the new repair-recovery compound “Ideal”, developed at the Institute of Geotechnical Mechanics named by N. Poljakov of National Academy of Sciences of Ukraine, provide an exceptionally low friction coefficient of 0.04–0.005 and ensure the durability of the protective layer under dry friction before failure, reaching 80–100 thousand cycles at a specific pressure of 529 MPa. At a specific pressure of 187–374 MPa, the protective layer under dry friction provides up to 1 million cycles of interaction. Originality. The unique properties of the combination of the “Ideal” tribotechnical composition, which forms a metal-ceramic, superhard, refractory, and wear-resistant nanostructured layer on a metal base, have been established. This layer provides protection against wear, dynamic loads, thermal and oxidative degradation, and increases the service life of friction units in industrial equipment by 3–10 times. Practical value. Based on the results of experimental and acceptance tests of the “Ideal” repair-recovery compound, a decrease in friction coefficient values and an extension of the service life of highly loaded gear mechanisms in mining and industrial equipment by 1.4–2.0 times have been established. It has been found that the protective layer provided by the “Ideal” repair-recovery compound helps reduce the wear mass of friction surfaces by 20 times in the tested samples, ensuring cleanliness of lubricants in equipment and increasing their operational lifespan while saving on maintenance costs.
{"title":"Improvement of the service life of mining and industrial equipment by using friction modifiers","authors":"V. Hovorukha, A. Hovorukha","doi":"10.33271/nvngu/2023-4/074","DOIUrl":"https://doi.org/10.33271/nvngu/2023-4/074","url":null,"abstract":"Purpose. Enhancement of the performance, service life and sustainability of industrial vehicles, mining machinery and various equipment by reducing the friction coefficient. Methodology. Laboratory research on assessing the interaction of friction pairs under external loading, rolling, and sliding in dry friction conditions, as well as the influence of friction modifiers. Industrial experimental studies on the performance indicators of mining machinery under the influence of friction modifiers. Findings. Actual diagrams depicting changes in the friction coefficient between the contacting surfaces of disc pairs were obtained for four specific loading periods and corresponding pressures of 529, 374, 274 and 187 MPa. These measurements were taken while the discs experienced a 10 % relative slippage and cyclic load interaction during the testing of specimens, with the presence of the repair-recovery compound called “Ideal” and without it, using only dry friction. The new technologies and the new repair-recovery compound “Ideal”, developed at the Institute of Geotechnical Mechanics named by N. Poljakov of National Academy of Sciences of Ukraine, provide an exceptionally low friction coefficient of 0.04–0.005 and ensure the durability of the protective layer under dry friction before failure, reaching 80–100 thousand cycles at a specific pressure of 529 MPa. At a specific pressure of 187–374 MPa, the protective layer under dry friction provides up to 1 million cycles of interaction. Originality. The unique properties of the combination of the “Ideal” tribotechnical composition, which forms a metal-ceramic, superhard, refractory, and wear-resistant nanostructured layer on a metal base, have been established. This layer provides protection against wear, dynamic loads, thermal and oxidative degradation, and increases the service life of friction units in industrial equipment by 3–10 times. Practical value. Based on the results of experimental and acceptance tests of the “Ideal” repair-recovery compound, a decrease in friction coefficient values and an extension of the service life of highly loaded gear mechanisms in mining and industrial equipment by 1.4–2.0 times have been established. It has been found that the protective layer provided by the “Ideal” repair-recovery compound helps reduce the wear mass of friction surfaces by 20 times in the tested samples, ensuring cleanliness of lubricants in equipment and increasing their operational lifespan while saving on maintenance costs.","PeriodicalId":19101,"journal":{"name":"Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43273021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-01DOI: 10.33271/nvngu/2023-4/048
V. Sobolev, N. V. Holub, O. Tereshkova
Purpose. To identify a mechanism in terms of which a signal of weak magnetic field is transformed into response of some components of nanostructure of a carbonaceous matter with further formation of chemical bonds. Methodology. Physical and mathematical modelling procedures of elementary chemical acts have been applied. Regularities of quantum mechanics and dynamics of chemical bonds were also used in addition to a magnetic isotope theory, a diffusion theory of recombination of radical pairs taking into consideration triplet-singlet transit, and nuclear-spin selectivity of chemical reactions. Findings. The physical mechanism of the magnetic scenario of interradial reactions is considered from the viewpoint of their energy stimulation through magnetic fields, i.e. the idea has been implemented according to which the number of radical pairs, able to be recombined into stable molecules, increases significantly if the weak magnetic field exercises certain influence. In addition to stimulation of interradial reactions, the magnetic field impact on organic coal mass-radicals results in stabilization of carbonaceous structures with regular atomic arrangement (being two-dimensional matrices, chains etc.) and their increase. Originality. A physical model of structural and phase changes in coal, depending upon the effect by external weak magnetic field, has been developed. It has been shown that the weak magnetic field signal, being incomparably smaller energetically to compare with the energy of thermal molecular motion, can initiate triplet-singlet transitions, i. e. transform radicals into reactive state. A mechanism has been proposed to form chemical bonds between movable radicals and non-complete bonds of atoms at the surfaces of solid phases of carbonaceous matter. Practical value. Implementation of the obtained results, concerning magnetic coal processing, may be connected with the development of a new procedure to avoid explosive conditions in coal seams. Progress in the field of magnetic processing should involve studies concerning calculation and selection of coal processing parameters (i.e. magnetic field density, frequency, energy, and a processing period) to control efficiently the chemical reactions in the carbonaceous matter. A substantiation degree of coal processing will influence greatly both efficiency of chemical processes and expediency of practical use of the results.
{"title":"Magnetic stimulation of chemical reactions in coal","authors":"V. Sobolev, N. V. Holub, O. Tereshkova","doi":"10.33271/nvngu/2023-4/048","DOIUrl":"https://doi.org/10.33271/nvngu/2023-4/048","url":null,"abstract":"Purpose. To identify a mechanism in terms of which a signal of weak magnetic field is transformed into response of some components of nanostructure of a carbonaceous matter with further formation of chemical bonds. Methodology. Physical and mathematical modelling procedures of elementary chemical acts have been applied. Regularities of quantum mechanics and dynamics of chemical bonds were also used in addition to a magnetic isotope theory, a diffusion theory of recombination of radical pairs taking into consideration triplet-singlet transit, and nuclear-spin selectivity of chemical reactions. Findings. The physical mechanism of the magnetic scenario of interradial reactions is considered from the viewpoint of their energy stimulation through magnetic fields, i.e. the idea has been implemented according to which the number of radical pairs, able to be recombined into stable molecules, increases significantly if the weak magnetic field exercises certain influence. In addition to stimulation of interradial reactions, the magnetic field impact on organic coal mass-radicals results in stabilization of carbonaceous structures with regular atomic arrangement (being two-dimensional matrices, chains etc.) and their increase. Originality. A physical model of structural and phase changes in coal, depending upon the effect by external weak magnetic field, has been developed. It has been shown that the weak magnetic field signal, being incomparably smaller energetically to compare with the energy of thermal molecular motion, can initiate triplet-singlet transitions, i. e. transform radicals into reactive state. A mechanism has been proposed to form chemical bonds between movable radicals and non-complete bonds of atoms at the surfaces of solid phases of carbonaceous matter. Practical value. Implementation of the obtained results, concerning magnetic coal processing, may be connected with the development of a new procedure to avoid explosive conditions in coal seams. Progress in the field of magnetic processing should involve studies concerning calculation and selection of coal processing parameters (i.e. magnetic field density, frequency, energy, and a processing period) to control efficiently the chemical reactions in the carbonaceous matter. A substantiation degree of coal processing will influence greatly both efficiency of chemical processes and expediency of practical use of the results.","PeriodicalId":19101,"journal":{"name":"Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47443276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-01DOI: 10.33271/nvngu/2023-4/150
T. Kapeliushna, A. Goloborodko, S. Nesterenko, I. Bezhenar, B. Matviichuk
Purpose. To analyze the changes caused by the acceleration of digitalization under conditions of uncertainty and note their impact on enterprise security management in this environment. Methodology. The methodological basis for the study was the theoretical provisions of enterprise security; legal regulations governing security and information protection, scientific works by domestic and foreign scholars on the issues of enterprise security management. The methods of analysis, synthesis, deduction, generalization and cognition were used in the study on the issue. Findings. The conditions of functioning of enterprises are analyzed, in particular, the security of enterprises is considered in conditions of uncertainty caused by the martial law imposed in Ukraine and the acceleration of digitalization of business processes as a result of the emergence of new challenges. Originality. A number of events are traced that preceded the increased interest in electronic services and active investment by enterprises related to e-commerce; artificial intelligence, big data; technology. The basis is investigated for the emergence of new challenges and threats associated with the active use of the Internet, applied solutions, servers, big data, data processing methods, the use of third-party software, i.e. the risks of violating the integrity, reliability, and confidentiality of information. The trends in measuring enterprise security are analyzed and the factors that strengthen the role of protecting information assets of enterprises and organizations are identified. It is proposed to pay more attention to ensuring the security of enterprises, taking into account not only physical but also invisible intrusions, such as: threats to information, the information field of enterprise functioning through a consistent response to cyber incidents/cyber-attacks by providing cybersecurity actors with protective stages: preparation, detection and analysis, deterrence, elimination, recovery, analysis of the efficiency of measures to respond to cyber incidents/cyber attacks. Practical value. The analysis carried out proves the relevance of the issues of enterprise security, the formation of changes in views on enterprise security in accordance with current trends and uncertain conditions. The findings of the study can be taken into account and practically implemented in the formation of the enterprise security policy, regardless of the field of activity.
{"title":"Analysis of digitalization changes and their impact on enterprise security management under uncertainty","authors":"T. Kapeliushna, A. Goloborodko, S. Nesterenko, I. Bezhenar, B. Matviichuk","doi":"10.33271/nvngu/2023-4/150","DOIUrl":"https://doi.org/10.33271/nvngu/2023-4/150","url":null,"abstract":"Purpose. To analyze the changes caused by the acceleration of digitalization under conditions of uncertainty and note their impact on enterprise security management in this environment. Methodology. The methodological basis for the study was the theoretical provisions of enterprise security; legal regulations governing security and information protection, scientific works by domestic and foreign scholars on the issues of enterprise security management. The methods of analysis, synthesis, deduction, generalization and cognition were used in the study on the issue. Findings. The conditions of functioning of enterprises are analyzed, in particular, the security of enterprises is considered in conditions of uncertainty caused by the martial law imposed in Ukraine and the acceleration of digitalization of business processes as a result of the emergence of new challenges. Originality. A number of events are traced that preceded the increased interest in electronic services and active investment by enterprises related to e-commerce; artificial intelligence, big data; technology. The basis is investigated for the emergence of new challenges and threats associated with the active use of the Internet, applied solutions, servers, big data, data processing methods, the use of third-party software, i.e. the risks of violating the integrity, reliability, and confidentiality of information. The trends in measuring enterprise security are analyzed and the factors that strengthen the role of protecting information assets of enterprises and organizations are identified. It is proposed to pay more attention to ensuring the security of enterprises, taking into account not only physical but also invisible intrusions, such as: threats to information, the information field of enterprise functioning through a consistent response to cyber incidents/cyber-attacks by providing cybersecurity actors with protective stages: preparation, detection and analysis, deterrence, elimination, recovery, analysis of the efficiency of measures to respond to cyber incidents/cyber attacks. Practical value. The analysis carried out proves the relevance of the issues of enterprise security, the formation of changes in views on enterprise security in accordance with current trends and uncertain conditions. The findings of the study can be taken into account and practically implemented in the formation of the enterprise security policy, regardless of the field of activity.","PeriodicalId":19101,"journal":{"name":"Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43823597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-01DOI: 10.33271/nvngu/2023-4/082
I. F. Alrefo, O. Matsulevych, O. Vershkov, S. Halko, O. Suprun, O. Miroshnyk
Purpose. To design a method for smoothing the working surfaces of stator and rotor with the use of computer simulation to eliminate the impact of the rotor on the stator when they interact. Methodology. Special and general methods of research have been used: interpolation of the point series – to determine the contour nodes of the rotor and the stator of the rotary-planetary machine; formation of B-splines – to construct a point series whose coordinates are structurally determined; technology of automated formation of curves in CAD-system SolidWorks – for modelling of functional surfaces of a planetary-rotary compressor. Findings. Algorithms for formation of the contours representing curves defined analytically or constructively with a given accuracy have been developed. The obtained contours are used in the CAD system as linear elements of the surface model. The developed method has been tested in the simulation of functional surfaces of a planetary-rotary compressor. Optimization of the body shape and rotor profiles in order to increase the productivity of the rotary-planetary machine has been carried out. Originality. The developed algorithms make it possible to determine the original point series belonging to any curve and provide a given interpolation accuracy when forming a B-spline contour or second-order curve arcs. Computer models of the body surfaces of the rotor are formed on the basis of the gear ratio of the planetary-rotary mechanism and the rotor dimensions. In order to increase the performance of the compressor, the working surfaces of the rotor have been optimized. The maximum volume of the working chamber was increased by increasing the radius of the moving gear of the planetary-rotary mechanism. In order to prevent the rotor from jamming during compressor operation, the rotor contour was changed. Practical value. The method for modelling the surfaces of complex shape in CAD-system has been developed on the basis of creating contours which with given accuracy represent lines from the surface determinant. This method makes it possible to form computer models of complex surfaces on the basis of a framework consisting of curves absent in CAD libraries.
{"title":"Designing the working surfaces of rotary planetary mechanisms","authors":"I. F. Alrefo, O. Matsulevych, O. Vershkov, S. Halko, O. Suprun, O. Miroshnyk","doi":"10.33271/nvngu/2023-4/082","DOIUrl":"https://doi.org/10.33271/nvngu/2023-4/082","url":null,"abstract":"Purpose. To design a method for smoothing the working surfaces of stator and rotor with the use of computer simulation to eliminate the impact of the rotor on the stator when they interact. Methodology. Special and general methods of research have been used: interpolation of the point series – to determine the contour nodes of the rotor and the stator of the rotary-planetary machine; formation of B-splines – to construct a point series whose coordinates are structurally determined; technology of automated formation of curves in CAD-system SolidWorks – for modelling of functional surfaces of a planetary-rotary compressor. Findings. Algorithms for formation of the contours representing curves defined analytically or constructively with a given accuracy have been developed. The obtained contours are used in the CAD system as linear elements of the surface model. The developed method has been tested in the simulation of functional surfaces of a planetary-rotary compressor. Optimization of the body shape and rotor profiles in order to increase the productivity of the rotary-planetary machine has been carried out. Originality. The developed algorithms make it possible to determine the original point series belonging to any curve and provide a given interpolation accuracy when forming a B-spline contour or second-order curve arcs. Computer models of the body surfaces of the rotor are formed on the basis of the gear ratio of the planetary-rotary mechanism and the rotor dimensions. In order to increase the performance of the compressor, the working surfaces of the rotor have been optimized. The maximum volume of the working chamber was increased by increasing the radius of the moving gear of the planetary-rotary mechanism. In order to prevent the rotor from jamming during compressor operation, the rotor contour was changed. Practical value. The method for modelling the surfaces of complex shape in CAD-system has been developed on the basis of creating contours which with given accuracy represent lines from the surface determinant. This method makes it possible to form computer models of complex surfaces on the basis of a framework consisting of curves absent in CAD libraries.","PeriodicalId":19101,"journal":{"name":"Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44346479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-01DOI: 10.33271/nvngu/2023-4/124
O. Lozhnikov, B. Sobko, A. Pavlychenko, Yu. O Kirichek
Purpose. To develop a methodology for determining the economically feasible distance of construction sand haulage, which is a secondary raw material of ore pits, to highway construction sites in comparison with the delivery of sand from mining enterprises of building materials, taking into account land conservation indicators. Methodology. The research used a set of methods: analytical method – to establish the main technical and economic indicators that affect the cost of delivering sand from the mining enterprises to the road construction site; technical and economic analysis – to determine the influence of the building materials haulage distance on the cost of construction works. Findings. The economically permissible haulage distance for sands form titanium-zirconium mining enterprises to highway construction objects was established in comparison with the involving of sands from deposits of building materials. It has been proven that under the conditions of using the sands of the Motronivskyi MPP, where the main raw material is titanium-zirconium ores, in addition to the economic effect of the mining waste disposal, there is an ecological effect of reducing the dumps and tailings areas. At the same time, the cost of sand rocks during the construction of the road surface will be reduced by 3 to 60 %, depending on the distance to the construction road site. All together, the area of lands saved from being disturbed by new mining operations will reach 3.3 hectares during the construction of a 2.5 km long category I-b road section. Originality. Dependence was established of the sand cost and its delivery to the object of new highway construction on the materials haulage distance when purchasing sand at the enterprise of the main raw material and from the titanium-zirconium deposit, where it is developed as an associated raw material. The dependence of the economic efficiency indicator of the road construction on the increasing distance of sand rocks delivery from the titanium-zirconium deposit was determined, which allows justifying the rational haulage distance according to technical and economic indicators. Practical value. The developed method for determining the effective haulage distance for sand rocks to the construction site allows one to calculate the expediency of involving associated minerals of ore pits during the reconstruction and construction of new highways, as well as to establish the effect of resource conservation due to the reduction in the area of mining facilities during the extraction of ore and building raw materials.
{"title":"Utilization of the secondary resources of titanium-zirconium pits when constructing highways","authors":"O. Lozhnikov, B. Sobko, A. Pavlychenko, Yu. O Kirichek","doi":"10.33271/nvngu/2023-4/124","DOIUrl":"https://doi.org/10.33271/nvngu/2023-4/124","url":null,"abstract":"Purpose. To develop a methodology for determining the economically feasible distance of construction sand haulage, which is a secondary raw material of ore pits, to highway construction sites in comparison with the delivery of sand from mining enterprises of building materials, taking into account land conservation indicators. Methodology. The research used a set of methods: analytical method – to establish the main technical and economic indicators that affect the cost of delivering sand from the mining enterprises to the road construction site; technical and economic analysis – to determine the influence of the building materials haulage distance on the cost of construction works. Findings. The economically permissible haulage distance for sands form titanium-zirconium mining enterprises to highway construction objects was established in comparison with the involving of sands from deposits of building materials. It has been proven that under the conditions of using the sands of the Motronivskyi MPP, where the main raw material is titanium-zirconium ores, in addition to the economic effect of the mining waste disposal, there is an ecological effect of reducing the dumps and tailings areas. At the same time, the cost of sand rocks during the construction of the road surface will be reduced by 3 to 60 %, depending on the distance to the construction road site. All together, the area of lands saved from being disturbed by new mining operations will reach 3.3 hectares during the construction of a 2.5 km long category I-b road section. Originality. Dependence was established of the sand cost and its delivery to the object of new highway construction on the materials haulage distance when purchasing sand at the enterprise of the main raw material and from the titanium-zirconium deposit, where it is developed as an associated raw material. The dependence of the economic efficiency indicator of the road construction on the increasing distance of sand rocks delivery from the titanium-zirconium deposit was determined, which allows justifying the rational haulage distance according to technical and economic indicators. Practical value. The developed method for determining the effective haulage distance for sand rocks to the construction site allows one to calculate the expediency of involving associated minerals of ore pits during the reconstruction and construction of new highways, as well as to establish the effect of resource conservation due to the reduction in the area of mining facilities during the extraction of ore and building raw materials.","PeriodicalId":19101,"journal":{"name":"Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45523379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-01DOI: 10.33271/nvngu/2023-4/138
Oleksandr Laktionov, Leonid Lievi, A. Tretiak, Mykola Movin
Purpose. Study on the process of combining several methods for determining the quality indices of human-machine interaction, containing various configurations for determining the weight coefficients in an ensemble. Methodology. The process of diagnosing the quality of the interaction of a human-machine system with four elements of subsystems is studied using the example of the system “Operator–Machining Center – Control Program – Safe Environment”. The main hypothesis of the study is the combination of several methods for determining the quality indices of human-machine interaction, containing different configurations for determining the weight coefficients in the ensemble. A combined method for diagnosing the quality of interaction between human-machine systems based on ensemble models, which include non-ensemble ones, has been proposed. The ensemble index has been determined by averaging the non-ensemble indices. The defined ensemble indices and element scores of the four subsystems are used as input scores to a multiple regression model to generate prediction. Findings. Four combinations of ensemble indices have been developed and implemented in software, which are characterized by a minimum value of the standard deviation compared to the existing ones. According to the results of experimental verification, the proposed models demonstrate the value of the standard deviation of 0.1404; 0.1401; 0.1411; 0.1397, and the existing ones are 0.1532; 0.1535; 0.1532; 0.1532. Originality. The combined ensemble method for diagnosing the quality of interaction between elements of subsystems takes into account linear models with non-linear variables and different ways of determining weight coefficients. Practical value. The scenario for the practical use of the results obtained is a possible option for optimizing production, where, depending on the final result, specialists can adjust the value of a particular subsystem to achieve the desired result.
{"title":"Investigation of combined ensemble methods for diagnostics of the quality of interaction of human-machine systems","authors":"Oleksandr Laktionov, Leonid Lievi, A. Tretiak, Mykola Movin","doi":"10.33271/nvngu/2023-4/138","DOIUrl":"https://doi.org/10.33271/nvngu/2023-4/138","url":null,"abstract":"Purpose. Study on the process of combining several methods for determining the quality indices of human-machine interaction, containing various configurations for determining the weight coefficients in an ensemble. Methodology. The process of diagnosing the quality of the interaction of a human-machine system with four elements of subsystems is studied using the example of the system “Operator–Machining Center – Control Program – Safe Environment”. The main hypothesis of the study is the combination of several methods for determining the quality indices of human-machine interaction, containing different configurations for determining the weight coefficients in the ensemble. A combined method for diagnosing the quality of interaction between human-machine systems based on ensemble models, which include non-ensemble ones, has been proposed. The ensemble index has been determined by averaging the non-ensemble indices. The defined ensemble indices and element scores of the four subsystems are used as input scores to a multiple regression model to generate prediction. Findings. Four combinations of ensemble indices have been developed and implemented in software, which are characterized by a minimum value of the standard deviation compared to the existing ones. According to the results of experimental verification, the proposed models demonstrate the value of the standard deviation of 0.1404; 0.1401; 0.1411; 0.1397, and the existing ones are 0.1532; 0.1535; 0.1532; 0.1532. Originality. The combined ensemble method for diagnosing the quality of interaction between elements of subsystems takes into account linear models with non-linear variables and different ways of determining weight coefficients. Practical value. The scenario for the practical use of the results obtained is a possible option for optimizing production, where, depending on the final result, specialists can adjust the value of a particular subsystem to achieve the desired result.","PeriodicalId":19101,"journal":{"name":"Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47782237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-01DOI: 10.33271/nvngu/2023-4/181
R. Sharanov, B. Vatchenko
Purpose. To characterize the features of crisis management of micro, small, medium and large enterprises during martial law. Methodology. Methods of analysis and synthesis, observation, generalization, and comparative analysis were used to fulfill the tasks and achieve the goal of the research. The methods of absolute, relative values, correlation and regression analysis were used in the development of the logit-model for estimating the probability of bankruptcy. The research’s information base was backed by the works of Ukrainian and foreign scientists, statistical materials, and Internet sources. Findings. The economic consequences of the military invasion in Ukraine are indicated the main challenges of business operation in contemporary conditions are identified. The features of crisis management of micro, small, medium and large enterprises are determined and two types of it are proposed: urgent and traditional. The specifics of crisis diagnostics are considered, providing methodological recommendations for analyzing the performance of various business entities based on the scale of their activities. For micro and small business entities, activity assessment indicators are proposed, which are based on a minimum amount of data and simple calculations, for medium and large ones – a comprehensive assessment using ratio analysis and models for assessing the probability of bankruptcy, including the authors’ own logit model, tested at Ukrainian enterprises. Anti-crisis measures are substantiated to improve business functioning during martial law, both at the enterprise and state levels. Originality. The concept of “urgent crisis management” has been introduced to characterize the functioning of micro and small business entities. A concept of enterprise crisis management during wartime has been developed and a methodical approach to the diagnosis of subjects of micro, small, medium and large enterprises has been improved. In particular, the authors’ logit model for assessing the probability of bankruptcy has been proposed. Practical value. Methodological recommendations have been provided for the implementation of enterprise crisis management based on the scale of entrepreneurial activities, aiming to enhance their functioning in contemporary wartime conditions. The study introduces and validates a logit model on Ukrainian enterprises, demonstrating its effectiveness. The research findings discussed in this paper can be used by economists-researchers and practitioners to enhance business efficiency.
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Pub Date : 2023-08-01DOI: 10.33271/nvngu/2023-4/110
V. Tsopa, S. Cheberiachko, O. Yavorska, O. Deryugin, О. M. Borovytskyi
Purpose. To improve the process of managing dynamic occupational risks, which considers changes in time in hazardous factors of the organization’s environment in the occupational safety and health management system. Methodology. To improve the process of managing occupational risks, we have applied a well-known “Bow-Tie” model (ISO 31010:2018). The model allows assessing occupational risks as the product of the probability of hazardous event occurrence and severity of the consequences, taking into account the influence of hazardous external and internal factors, hazardous actions or dangerous inactions, which, according to the requirements of Clause 4.1 of the ISO 45001:2018 standard, are interconnected and subject to the influence of time. Findings. A model of the connection of hazardous factors of the internal and external environment of an organization, related to their negative influence on the growing probability of hazardous event (incident) occurrence and a degree of severity in time, has been developed. The process of managing occupational risks is proposed, taking into account changes in the time of exposure to hazardous factors, which will allow determining the acceptability or unacceptability of the occupational risk in time. The analysis of changes in occupational risks is proposed to be considered in the following time intervals (specifically in those where there is a corresponding change in risk factors): time of the day, day of the week, month of the year, quarter, half year, year, years etc. All the proposed professional risks were divided into two groups of professional risks considering the changes in their levels in time: static and dynamic ones. To calculate the occupational risk level, it is also proposed to determine all combinations of hazardous factors that can occur simultaneously in time within the corresponding intervals of the time under analysis. Originality. It has been determined that identification of the acceptable level of an occupational risk in the maximum combination of all hazardous factors acting simultaneously at a certain point in time will lead to the fact that all other combinations of hazardous factors will also have an acceptable level of occupational risk. This provision follows from the fact that the level of occupational risk from a smaller number of hazardous factors will not exceed the indicator of occupational risk from the exposure to a larger number of hazardous factors in time. Practical value. The forms for dynamic occupational risk assessment have been developed; a matrix has been proposed for determining the number of combinations of hazardous factors acting simultaneously in time.
{"title":"Improving a process of managing dynamic occupational risks","authors":"V. Tsopa, S. Cheberiachko, O. Yavorska, O. Deryugin, О. M. Borovytskyi","doi":"10.33271/nvngu/2023-4/110","DOIUrl":"https://doi.org/10.33271/nvngu/2023-4/110","url":null,"abstract":"Purpose. To improve the process of managing dynamic occupational risks, which considers changes in time in hazardous factors of the organization’s environment in the occupational safety and health management system. Methodology. To improve the process of managing occupational risks, we have applied a well-known “Bow-Tie” model (ISO 31010:2018). The model allows assessing occupational risks as the product of the probability of hazardous event occurrence and severity of the consequences, taking into account the influence of hazardous external and internal factors, hazardous actions or dangerous inactions, which, according to the requirements of Clause 4.1 of the ISO 45001:2018 standard, are interconnected and subject to the influence of time. Findings. A model of the connection of hazardous factors of the internal and external environment of an organization, related to their negative influence on the growing probability of hazardous event (incident) occurrence and a degree of severity in time, has been developed. The process of managing occupational risks is proposed, taking into account changes in the time of exposure to hazardous factors, which will allow determining the acceptability or unacceptability of the occupational risk in time. The analysis of changes in occupational risks is proposed to be considered in the following time intervals (specifically in those where there is a corresponding change in risk factors): time of the day, day of the week, month of the year, quarter, half year, year, years etc. All the proposed professional risks were divided into two groups of professional risks considering the changes in their levels in time: static and dynamic ones. To calculate the occupational risk level, it is also proposed to determine all combinations of hazardous factors that can occur simultaneously in time within the corresponding intervals of the time under analysis. Originality. It has been determined that identification of the acceptable level of an occupational risk in the maximum combination of all hazardous factors acting simultaneously at a certain point in time will lead to the fact that all other combinations of hazardous factors will also have an acceptable level of occupational risk. This provision follows from the fact that the level of occupational risk from a smaller number of hazardous factors will not exceed the indicator of occupational risk from the exposure to a larger number of hazardous factors in time. Practical value. The forms for dynamic occupational risk assessment have been developed; a matrix has been proposed for determining the number of combinations of hazardous factors acting simultaneously in time.","PeriodicalId":19101,"journal":{"name":"Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47137154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Purpose. To study the uncertainty of globalization influences on strategic planning (SP). To identify peculiarities of SP for enterprises of Ukraine. To develop methods for evaluating the SP effectiveness in conditions of uncertainty and changes in the level of uncertainty in parameter sequences for relevant forecasting. Methodology. The study used the following methods: critical analysis – to identify the peculiarities of SP in Ukraine; mathematical formalization – to evaluate the efficiency of SP; method of comparing the first derivatives – for the current assessment of the rate of change in economic indicators and their approximation to the target values of SP; analysis and synthesis – to establish the uncertainty levels of the input and outputs sequences of each of the parameters of globalization. Findings. It is stated that different vectors of globalization influences cause formation of a complex “competitive landscape”, which increases the uncertainty of SP. Stratification of requirements for formation of strategic plans and opportunities which they allow implementing is proposed, as well as stratification of indicators of globalization influence. The factors of globalization influence on the formation of uncertainty in the activities of Ukrainian enterprises are studied and the peculiarities of this influence on the SP process are indicated. Originality. An assessment of the level of approximation of the actual and target results of enterprise’s activity is proposed as an indicator of SP effectiveness. A comparison of first derivatives of the efficiency indicator was used to reduce the uncertainty in estimating the rates of dynamic approximation of the actual and forecast results. A method of ordering heterogeneous sequences is proposed for a relevant assessment of the change in the level of uncertainty in parameter sequences. Practical value. The proposed approach reduces conceptual SP ambiguity. The developed method for assessing the uncertainty of globalization effects on SP and identifying the SP peculiarities in conditions of uncertainty will increase SP relevance for Ukrainian enterprises.
Pub Date : 2023-08-01DOI: 10.33271/nvngu/2023-4/040
S. Us, O. Ishchenko, D. Koba, K. Ishchenko
Purpose. Using experimental and theoretical studies to justify the rational location of charges of various types and their technological parameters in the fan, taking into account the physical and mechanical properties and structural features of the rocks in the mountain massif. Methodology. In the experiments, an improved method of geostructural analysis of rocks was used to obtain detailed data on their properties, the block structure of the massif, and the type and direction of development of crack systems. Identification of crack systems, their density, intensity, and direction of development of crack systems is carried out on petrographic sections using microscopic analysis, these are used to calculate the average indicator of the cracking coefficient, while the funneling method – the anisotropy coefficient. The justification of the rational location and the number of charges in each fan was performed using the methods of genetic algorithms and the developed software product. Findings. The coefficient of cracking and anisotropy of physical and mechanical properties of uranium ores was calculated, which was 78 cr/sm2 and 1.4, respectively. According to the developed mathematical models and the software product, the optimization problem was solved using genetic algorithms, which determined the main priorities: the location of the charge in the fan according to the structure of the massif and the rational diameter of the well, which helps to limit the number of oversized blocks of reflected ore. Originality. The regularities are established of the change in the anisotropy coefficient from the cracking coefficient, the nature of the distribution and the number of microcracks (cr/sm2) in the quartz grains, which is present in uranium ore according to a linear law, and the output (in %) of oversized blocks during the destruction of uranium ore from the cracking coefficient – according to the polynomial law. For the first time, the optimal location and the number of charges in each fan, the diameter of the wells, taking into account the type of rock, its strength and fissure, and the geometric parameters of the ore deposit, were determined based on the constructed mathematical models and the developed software product. Practical value. The indicated results of the experimental and theoretical studies will form the basis for the development and substantiation of rational parameters of resource-saving and seismically safe methods for breaking strong rocks of complex structure during the extraction of uranium and iron ores by the energy of the explosion in mines.
{"title":"Selection and justification of drilling and blasting parameters using genetic algorithms","authors":"S. Us, O. Ishchenko, D. Koba, K. Ishchenko","doi":"10.33271/nvngu/2023-4/040","DOIUrl":"https://doi.org/10.33271/nvngu/2023-4/040","url":null,"abstract":"Purpose. Using experimental and theoretical studies to justify the rational location of charges of various types and their technological parameters in the fan, taking into account the physical and mechanical properties and structural features of the rocks in the mountain massif. Methodology. In the experiments, an improved method of geostructural analysis of rocks was used to obtain detailed data on their properties, the block structure of the massif, and the type and direction of development of crack systems. Identification of crack systems, their density, intensity, and direction of development of crack systems is carried out on petrographic sections using microscopic analysis, these are used to calculate the average indicator of the cracking coefficient, while the funneling method – the anisotropy coefficient. The justification of the rational location and the number of charges in each fan was performed using the methods of genetic algorithms and the developed software product. Findings. The coefficient of cracking and anisotropy of physical and mechanical properties of uranium ores was calculated, which was 78 cr/sm2 and 1.4, respectively. According to the developed mathematical models and the software product, the optimization problem was solved using genetic algorithms, which determined the main priorities: the location of the charge in the fan according to the structure of the massif and the rational diameter of the well, which helps to limit the number of oversized blocks of reflected ore. Originality. The regularities are established of the change in the anisotropy coefficient from the cracking coefficient, the nature of the distribution and the number of microcracks (cr/sm2) in the quartz grains, which is present in uranium ore according to a linear law, and the output (in %) of oversized blocks during the destruction of uranium ore from the cracking coefficient – according to the polynomial law. For the first time, the optimal location and the number of charges in each fan, the diameter of the wells, taking into account the type of rock, its strength and fissure, and the geometric parameters of the ore deposit, were determined based on the constructed mathematical models and the developed software product. Practical value. The indicated results of the experimental and theoretical studies will form the basis for the development and substantiation of rational parameters of resource-saving and seismically safe methods for breaking strong rocks of complex structure during the extraction of uranium and iron ores by the energy of the explosion in mines.","PeriodicalId":19101,"journal":{"name":"Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48948093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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