Vol 19, No 2 (2023)
MATHEMATICAL MODELING AND INFORMATION TECHNOLOGIES
About some approaches for converting test scores into grades
Abstract
Subject of research: Computer testing for evaluating the results of mastering an academic discipline in a higher educational institution.
Purpose of research: The problem of subjectivity in determining threshold values when translating test scores (from 0 to 100) into the usual five-point scale of marks.
Methods and objects of research: It is proposed to use methods of mathematical statistics for processing test results data in determining the threshold values of test scores.
Main results of research: The approaches currently used in practice are considered and evaluated. Variants of alternative approaches to solving the problem are proposed.
9-16
Determination of unknown parameters of a piecewise linear risk function by the method of mixed estimation
Abstract
Subject of study: the problem of determining the parameters of a piecewise linear risk function.
The purpose of the study: apply the apparatus of linear-Boolean programming to solve this problem.
Methods and objects of research the object of the study is the formalization of a meaningful statement of the problem of minimizing the risk of undesirable consequences of the functioning of the analyzed system, the methods are regression analysis and the apparatus of mathematical programming.
The main results of the study an approach to determining estimates of the parameters of a piecewise linear risk function by using the mixed estimation method is described, which allows us to reduce this problem to a problem of linear Boolean programming. Numerical example solved.
17-21
Decision support models and methods to analysis and development in the IT services and equipment repair organizational and production processes management field
Abstract
Subject of research: is the models and decision support methods in the field of organizational management and IT services and equipment repair production processes.
Purpose of research: is to analyze existing and create new models, algorithms and technologies for the implementation of a decision support system for the service platform in the field of IT and equipment repair.
Methods and objects of research: include systems management theory, decision theory, automatic text processing methods, automatic control theory, information systems design theory, optimization theory and object-oriented programming.
Main results of research: is a prototype aggregator platform, reflecting services in the IT and equipment repair, system architecture, development tools, interface.
22-30
Computational algorithms for a one-dimensional MEP model of charge transfer in semiconductors
Abstract
Subject of research: hydrodynamic model describing charge transfer in semiconductor devices in the one-dimensional case.
Purpose of research: to develop computational algorithms for finding a numerical solution of a ballistic diode problem.
Methods and objects of research: the object of research is the ballistic diode problem. The developed computational algorithms are based on the use of the method of lines, the method of establishment, various non-stationary regularizations and schemes without saturation.
Main results of the research: computational schemes were developed based on the use of the spline function technique, on reducing the problem to integral equations and using the predictor-corrector scheme.
31-42
New materials and technology
Influence of continuous ion beams on the changes in the morphology of surface layers and performance properties of a tungsten-free hard alloy of KNT16 grade
Abstract
Subject of research: the article studies the effect of continuous ion beams of Ar++Zr+ and N++Ti+ compositions, with ion energy E = 20 keV and radiation dose D = 5⸱1017 ion/cm2, on the change in morphology, microhardness and wear resistance during finishing turning processing of metal-cutting plates made of tungsten-free hard alloy grade KNT16 (TiCN-Ni-Mo).
The purpose of the study: the development of technological modes of ion-beam processing aimed at improving the operational characteristics of metal-cutting tools from tungsten-free hard alloys of the TiCN-Ni-Mo system.
Methods and objects of research: the object of research was metal-cutting plates made of tungsten-free hard alloy grade KNT16 in the initial state and after modification of their surface layers by continuous ion beams of Ar++Zr+ and N++Ti+. The change in the wear resistance of cutting inserts after ion modification was estimated by constructing kinetic curves of wear of the rear surfaces of the inserts during finishing turning of bars made of 40KhN steel. The microhardness of the samples was determined using a Shimadzu HMV-2 microhardness tester using the Vickers method. The change in surface morphology was assessed using atomic force microscopy on an Ntegra prima scanning probe microscope.
Research results: using the method of atomic force microscopy, using the N++Ti+ beam as an example, it was shown that ion-beam treatment leads to selective sputtering of the binder phase in a thin surface layer of the irradiated hard alloy. It has been experimentally determined that ion modification contributes to an increase in the average service life of cutting inserts by 40–60% compared to the initial ones during finishing turning of 40KhN steel in the normalized state. It has been established that ion irradiation with an Ar++Zr+ beam leads to an increase in the average value of the microhardness of the KNT16 alloy by ~ 20%, and with an N++Ti+ beam by ~ 10%. Physicochemical processes are proposed that are responsible for changes in the properties of metal-cutting inserts made of tungsten-free hard alloy KNT16 as a result of modifying its surface layers with ion beams.
45-52
WC-10 wt.%Co hard alloy fabrication via spark plasma sintering of mechanically activated powders
Abstract
Subject of research: the paper presents a method of hard alloy fabrication via spark plasma sintering technology performed for mechanically activated powders of mixed WC compositions with 10 wt % Co.
Methods and objects of research: mechanical activation of the powders was carried out in a ball planetary mill by wet milling/stirring in anhydrous isopropanol medium using a milling container and balls made of WC.
Main results of research: the paper presents experimental data on the densification dynamics (kinetics and sintering stages) during spark plasma sintering at temperatures of 1000, 1100, 1150 and 1200 °С. The results of studies of the phase composition, microstructural organization and physical and mechanical properties of WC-10wt.%Co hard alloy are given. Optimal sintering parameters (1200 °C, 9 min) are determined. Hardness and mechanical strength of WC-10wt.%Co hard alloy samples increase as the sintering temperature increases with reaching the density of 99.6 % of the theoretical value. It is shown that with increasing temperature from 1000 to 1200 °C the average WC grain size slightly increases from 3.3 μm to 3.9 μm with increasing contribution of the share of larger grains with size > 4 μm.
53-60
Nanotechnologies in catalytic processes of oil refining and petrochemistry: market analysis, existing experience and prospects
Abstract
Purpose of research: is to consider the features of the use of nanotechnology in the catalytic processes of oil refining and petrochemistry.
Subject of research: the possibility of increasing the efficiency of catalytic processes in production using nanoparticles.
Object of research: nanotechnologies in catalytic processes of oil refining and petrochemistry of the Russian market.
Methods of research: statistical and comparative analysis, an analytical review of research literature, both analytical materials of oil and gas industry research and the latest developments based on the results of conference publications were used; articles from online sources.
Main results of research: the specific properties and effects of the use of nanocatalysts, compared with massive analogues, are described. The features of the organization of nanocatalytic processes are given. Nanotechnologies used at Russian oil refineries as part of the processes of catalytic cracking, catalytic reforming, and hydrotreating are analyzed. A general idea of the market of nanocatalysts, its volume, trends and prospects for further development is given. The problematic issues related to the use of nanotechnology, the supply of equipment from abroad, the peculiarities of the synthesis of nanoparticles are identified. The analysis carried out in the article allows us to draw conclusions about the strategic directions for the development of nanotechnologies in Russia. According to the results of the study, the shortcomings of the technology for the use of nanoparticles were also identified, these include large financial and time costs, the need to import certain types of equipment and technologies, lagging behind the most advanced countries in terms of the depth of oil refining.
61-67
Computer analysis and rapid assessment of data obtained by measuring residual stresses after vibration-hardening of samples
Abstract
Subject of research: is the use of computer analysis in measuring residual stresses. The purpose of the study is to create a program for evaluating and clustering numerical data obtained during the measurement of residual stresses.
Object of research: is a computer model of experimental data processing. This model uses a modified order of approximation of data received from sensors.
Main results of research: a program of computer analysis and rapid evaluation of numerical data has been developed. With the help of a software product, in the R programming language, calculated and experimental data are processed automatically. In the structure of the mathematical model for calculating residual stresses, a principle of a different order of approximation is introduced, which approximates not the result of multi-stage calculations, but the data obtained from sensors. This solution makes it possible to reduce the error of calculations and increase the adequacy of the model as a whole, and the developed program makes it possible to quickly evaluate the measurement results.
68-74
CRIMINAL AND EXECUTIVE LAW
Purpose and tasks of punishment
Abstract
Subject of research: is the norms of the criminal law devoted to the purposes of criminal punishment.
Purpose of the study is to determine the purpose and objectives of punishment, as well as the need for their legislative consolidation.
Methods of research: due to the specifics of the study, the methods of system-structural and functional analysis are used as the main ones.
Main results of research: since punishment is a consequence of the commission of a crime, it is self-sufficient and does not need an essential goal-setting, as a result of the conducted research, we believe that it is necessary to abandon the formulation of the purpose of punishment in the Criminal Code of the Russian Federation.
77-82
Curious interpretation of criminal legal rules, including liability for theft
Abstract
Subject of research: the erratological aspect of the interpretation of criminal law norms that provide for criminal liability for theft, that is, interpretive errors of Art. 158 of the Criminal Code of the Russian Federation. In this regard, this paper considers a number of modern publications devoted to the qualification of thefts, in which curious (ridiculous) errors of signs of theft, objective and subjective signs of theft and qualifying signs of secret theft of property were made.
Purpose of research: to identify the most serious errors in the interpretation of Art. 158 of the Criminal Code of the Russian Federation and the possibility of their elimination.
Methods of research: the dialectical method of cognition was used in combination with a systematic approach and instrumental methods.
Main results of research: the study shows that modern publications on the classification of thefts contain many curious errors that indicate the presence of doctrinal gaps and the need to eliminate them through a systemic interpretation.
83-88
Qualification of digital crimes against person: problematic issues
Abstract
Subject of the research is the norms of the criminal law establishing responsibility for crimes against the person, as well as explanations reflected in the Resolutions of the Plenum of the Supreme Court of the Russian Federation No. 58 of December 24, 2019, No. 46 of December 25, 2018, No. 16 of December 04, 2014.
Purpose of the research is to improve the criminal law and law enforcement practice in terms of the qualification of new ways of committing «traditional» crimes against the person (murder, kidnapping, human trafficking, depraved acts, violations of the inviolability of the home), as well as socially dangerous acts, responsibility for which is not directly enshrined in the criminal law, but having the ability to harm human rights and personal freedoms in the conditions of digitalization (deepfakes, stalking, cyberbullying).
Methods and objects of research: one of the methods used was the formal logical approach to the cognition of legal phenomena; also, the methods used were methods of analogy, generalization, differentiation, comparative-legal and formal-legal methods of research of public relations in the field of protection of individual rights and freedoms.
Main results of research: is proposals have been formulated for the qualification of actions aimed at harming the individual through the use of modern technologies, as well as for improving the norms of the current criminal law and the provisions of the Resolutions of the Plenum of the Supreme Court of the Russian Federation in terms can influence the criminal legal assessment of the act in the conditions of criminal use of digital technologies against the individual.
89-104
Socio-demographic characteristics of those convicted of criminal logging of forest plantations on the territory of the khanty-mansi autonomous okrug – yugra
Abstract
Subject of research: socio-demographic characteristics of a criminal convicted of an act provided for in Article 260 of the Criminal Code of the Russian Federation.
The purpose of the study: based on the analysis of the judicial practice of the Khanty-Mansi Autonomous Okrug – Yugra in cases of illegal logging (Article 260 of the Criminal Code of the Russian Federation), to propose a socio-demographic characteristic of convicted persons in the autonomous district.
Methods and objects of research: the methodological basis is represented by the dialectical method of scientific cognition. In the process of research, specialized methods of cognition were used. Thus, when presenting the empirical material, formulating the results, and drawing conclusions of the research, methods of formal logic were applied. In compiling the socio-demographic characteristic of convicted persons, analysis, synthesis, as well as the comparative legal method were used.
The main results and conclusions based on the results of the study: convicted persons for committing illegal logging are male individuals aged 50 years and older, with a secondary education, and currently unemployed.
105-112
POWER INDUSTRY
Experimental determination of static characteristics of loads in nodes of a 6 kv power supply system
Abstract
Subject of research: static characteristics of nodes of 6 kV power supply systems with asynchronous load.
Purpose of research: experimental determination of static characteristics by active and reactive power, calculation of the reserve coefficient by static stability of a node with asynchronous load.
Object of research: power supply systems with a complex load, which includes asynchronous motors.
Main results of research: the results of an active experiment to determine the static characteristics of the load node are presented. The measurements were carried out using devices that record the quality of electricity. Voltage regulation was carried out by the RPN device, the current transformers on the input switch were selected as the connection point of the device. Static characteristics of active and reactive power were constructed using interpolation and extrapolation tools. The critical voltage of the load node is determined. The coefficient of static stability margin is determined.
115-123
Application of neural networks for prediction of power consumption parameters
Abstract
Research was carried out within the framework of the state task of the Ministry of Science and Higher Education of the Russian Federation (topic “Development of wavelet analysis models for non-stationary modes of electrical networks to improve the reliability and efficiency of power supply to consumers”, topic code: FENG-2023-0005).
Subject of research: predictive neural network model for a daily load schedule.
Purpose of the study: prediction of power consumption based on the graph of electrical loads using a hybrid neural network.
Object of research: methods for predicting the parameters of the power supply system.
Main results of research: the results of forecasting the parameters of the power supply system based on daily load curves are presented. The simulation was carried out in the MATLAB software package. As a forecasting tool, a neural network was used, for the training of which load values averaged over half-hour time intervals and coefficients characterizing daily load schedules were used. The results obtained showed that the hybrid network gives a fairly accurate result, thereby confirming the adequacy of using a neural network to predict power or electricity consumption. The results of the study can be used for short-term forecasting and other parameters of the power supply system.
124-132
Improving the quality of electricity in power supply systems with reservation from diesel generator plants
Abstract
Subject of research: substantiation of the parameters and application of FACTS-devices of the STATCOM type for improving the quality of electricity in power supply systems with redundancy from diesel generator sets.
Purpose of research: is to substantiate technical solutions based on semiconductor devices with reactive and active power generation aimed at improving the quality of electricity in remote power supply systems powered in backup mode from diesel generator sets.
Methods and objects of research: fast Fourier transform, instantaneous power theory, simulation in Matlab Simulink. The object of research is the power supply system with a complete transformer substation 10/0.4 kV and redundancy from diesel generator sets.
Main results of research: the article presents the features of ensuring the redundancy of the considered power supply system, taking into account the quality of electricity and the rationale for technical solutions to improve it when supplying the household loads of the village in the backup mode from the DGU based on simulation modeling. A spectral analysis of a sharply variable load curve was performed. It is proposed to use a three-level STATCOM at a voltage of 0.4 kV with a supercapacitor storage, which requires less storage energy than a buffer storage, to ensure the quality of electricity when powered by a diesel generator set. The results of the studies carried out testify to the prospects of using STATCOM with a storage device to improve the quality of electricity in low-voltage networks.
133-143
Method and the device of actualization of controlling effect loading of knot of the electric power system
Abstract
Subject of research: is the technique of identification СCL in electric power system knots.
Purpose of research: consists in working out of a technique of monitoring of changes КREL in electric power system knot.
Methods of research: imitating modelling of electric modes, digital processing of signals, method of natural experiment.
Main results of research: the technique of monitoring КREL of knot of an electric power system of digital processing of the information based on a method has been as a result developed, having author's specific features, also has criteria of suitability of data and the device realising a technique is developed. Experimental approbation of work of the device analyzing data from means of a telemetering, an operatively-measuring complex or automated data management system is spent. Device check has shown, that on an indication range 0,75 … 1,2Uном the error of identification КREL has made 0,2 % that speaks about high reliability of an offered technique of actualisation КREL.
144-152