Analysis Apparatus Research Articles

Формирование экосистемы импакт-инвестирования в современных условиях

The subject of the study is the investment processes that arise during the implementation of Russia's social policy aimed at solving problems of improving the quality of life of society. The purpose of this study is impact investment, which is actively used for the implementation of social and environmental projects. Due to the fact that the dynamics of its volumes in the world in recent years has shown steady growth against the background of the developing global trends of the financial crisis, the objectives of the work are to establish the characteristics of the ecosystem of impact investment in Russia, to determine the factors constraining its development. Based on the analysis of the concept of impact investment, interpreted differently in the works of various authors, the main participants in the impact investment process are identified, criteria that distinguish transformative investment from other forms of money investment are identified. The author's model of the impact investment ecosystem is proposed, focused on the national architecture of the financial market. It is concluded that it is necessary to develop separate areas of methodological apparatus for impact investment analysis. It allows not only to describe the interaction of the main participants in this process and financial instruments, but also a system of specific assessment, which can subsequently be laid down as the basis for management decisions by investors and managers of socially significant social and environmental projects.

Factors influencing innovative development and inventive activity: experience of eu member countries

The article is devoted to the analysis of factors influencing innovative development and inventive activity in EU member states. It clarifies the changes in Ukraine’s positions in international rankings including the Global Innovation Index, and the Global Startup Ecosystem Index. The authors havehighlighted the main problems of creating and using inventions in Ukraine and outlined the modern model of commercialization of scientific and technical developments that was formed in the world market. A set of measures applied to increase the level of innovativeness in the European practice is given. To identify the main factors influencing the inventive activity of the EU member states and to assess the nature of such influence, the apparatus of correlation-regression analysis was used. Based on the data of the Statistical Bureau of the European Union for 2009-2021, three regression models of the influence of independent variables on the indicator of the number of patent applications to the European Patent Office (per one million inhabitants) were built. It is substantiated that the priority for Ukraine in the conditions of post-war recovery is taking into account the best standards of European countries, implementing several measures to support scientific and inventive activities, and using intellectual property objects in a practical way.

ПРОГНОЗИРОВАНИЕ МАКСИМАЛЬНОЙ ЭЛЕКТРИЧЕСКОЙ НАГРУЗКИ НА ОСНОВЕ РАНГОВОГО АНАЛИЗА ТЕХНОЦЕНОЗОВ

The paper presents the results of research, which consists in the use of the rank analysis apparatus for the problem of predicting the maximum electrical loads in the regional electrical complex. Empirical data for forecasting are data on maximum electrical loads on summer and winter regime days for six years, registered at 39 substations of the voltage level of 110 kV of the branch of РJSС RОSSЕТI North Caucasus - Sevkavkazenergo. The reliability of the forecast for the summer regime day is more than 92%, for the winter regime day the level of the forecast reliability is not sufficient, which determines the promising direction of further research.

Thermal Adsorption and Mechanical Behaviour of Polypropylene Hybrid Composite Synthesized by Glass/Hemp Fibre via an Injection Moulding Process

Thermoplastic-based polymers are gathering importance in several engineering fields like electrical, electronic, automotive, aerospace, and structural. The additions of secondary phase reinforcements such as natural and synthetic fibre improve thermoplastic-based polymer’s properties. The thermoplastic and natural fibre combinations are found to have low mechanical strength and incompatibility and need special treatment for synthesizing the natural fibre. The present experimental investigation deals with the enhancement of polypropylene hybrid composite by using the combinations of glass (synthetic)/hemp (natural) fibre for the ratio of 0 : 35, 5 : 30, 10 : 25, and 15 : 20 reinforced with 5 wt% compatibilizer through injection moulding. The revealed test results of polypropylene hybrid composite showed improved mechanical impact and flexural and tensile strength of 37.5%, 14.2%, and 21.1%, respectively. The thermal adsorption characteristics were evaluated by thermogravimetric analysis apparatus. It showed the decomposition of composite limited by hemp fibre at 27°C to 700°C.

Acceleration of Isothermal ω Phase Formation by Oxygen Addition in Ti–Nb Alloys during Cooling Process

The effect of oxygen addition on the microstructure formation during cooling from the β phase in the Ti–Nb alloy was investigated. The alloy ingots of Ti–(13∼20) at%Nb–(0∼3) at%O were arc-melted. They were homogenized at 1200°C for 3.6 ks and then hot-rolled at 850°C into 1.5 mm thick sheets. The disk specimen of 3 mm diameter was heated up to β phase field at 1000°C in the differential thermal analysis apparatus. And then specimen was cooled to room temperature at a cooling rate of 20°C/min. The β → α transformation was accelerated by the oxygen addition in Ti–(13∼15) at%Nb alloys. On the other hand, the oxygen addition promoted β → isothermal ωi transformation in Ti–(16∼20) at%Nb alloys. The promoting effect increased up to 1.5% oxygen, but the effect weakened by adding more than 1.5 at% oxygen in Ti–(18, 20) at%Nb alloys. The addition of oxygen over 3.0 at%O might suppress the β → ωi transformation in Ti–20 at%Nb alloy.

Non-standard analysis in electrical engineering. Transient analysis in second-order electrical circuits with violation of switching laws

For the first time, the authors proposed the use of the mathematical apparatus of non-standard analysis to solve certain non-trivial problems of theoretical electrical engineering. It was established that the axiomatics of non-standard analysis allows to simplify the analysis of transient processes in high-order electric circuits when the switching laws are violated. It is shown that the application of non-standard analysis methods in theoretical electrical engineering provides an opportunity to use the traditional classical method of transient processes analysis of circuits with violation of switching laws. Only by using methods of non-standard analysis, it is possible to strictly prove the fulfillment of the law of energy conservation in such schemes. Also, examples of solving such tasks are given. It is recommended to expand the scope of application of non-standard methods of analysis in problems of various branches of science and technology, which use differential calculus and boundary transitions, and the solution of which is limited or impossible by standard approaches.

IMPLEMENTATION OF STRENGTH CALCULATION SOFTWARE BASED ON THE SEMI-ANALYTICAL METHOD OF FINITE ELEMENTS

One of the main and responsible stages of creating an apparatus for numerical analysis of structures using the finite element method is its implementation in the form of a set of programs. The principles of complex construction should take into account modern requirements for strength calculation software in modern calculation complexes. Among them, first of all, automation of the main stages of the computing process, rational use of the resources of the operating and external memory of storage devices, non-closedness in relation to the classes of problems to be solved, algorithms for the task of input data, the method of discretization and solution of systems of equations and etc. In addition, the structure of the programs should take into account the specifics of the semi-analytical method of finite elements, for which such a large experience of creating developed systems of mathematical support for the search of spatial structures has not yet been accumulated, as when using the traditional version of FEM. Considerable experience in solving finite element mechanics problems, accumulated over the past decades, has been reflected in a number of industrial commercial software complexes of domestic (LIRA, SCAD) and foreign (ANSYS, Nastran, ABAQUS) production. The developed finite element base of these software complexes allows you to obtain solutions to a wide range of problems of the mechanics of a deformable rigid body for objects of different dimensions, including for massive spatial bodies, and convenient means of input-output of information and processing of the obtained results make them very accessible to a wide circles of users and allow to display the obtained results with the maximum degree of visibility. There are also object-oriented complexes created at manufacturing enterprises and research institutes, for example at the Institute of Strength Problems of the National Academy of Sciences of Ukraine, at the Dnipropetrovsk National University.
 The conducted research will determine the most optimal ways of solving the listed problems from the point of view of computing costs and complexity of implementation, as well as outline the circle of unsolved issues.

Рекрутирование губернаторского корпуса в современной России: эволюция патрональных сетей (2017—2021)

The article presents an attempt to study the structural dynamics of federal-regional political networks in the process of recruiting heads of the regions. The authors focus their attention on the current stage of the evolution of the federal center’s approach towards the formation of the governor’s corps, which began with the change of the team in the presidential administration in the second half of 2016. The theoretical framework of the study is the concepts of patron-client relations and patronal politics. For the empirical testing, the authors employ the apparatus of the Social Network Analysis (SNA), which makes it possible to assess both the political elite itself and the specific influence of individual figures. The conducted research documents a distinct tendency towards the growing structural complexity of the federal-regional patronal network, when an increasing number of federal actors are directly or indirectly involved in the process of recruiting regional leaders, which entails the formation of new intra-elite connections. However, despite the intensive personnel rotation, the tectonic shifts in the structure of patronage are not visible. The backbone of the network remains unchanged and contains on the stable basis a part of the federal political and economic elite, who looks to the leader of the state and enjoys his support. At the same time, the process of the growing complexity of the patronal network is accompanied by an increase in the importance of the President of the Russian Federation, primarily from the point of view of intra-network coordination, which, according to the authors, indicates a rising demand for such coordination in the modern Russia.

APPLICATION OF CLUSTER ANALYSIS IN SMART GRID NETWORKS

The task of developing and improving intelligent multi-agent control systems, which provide opportunities for intelligent online analysis of the electrical power supply system provided by the smart grid system, is considered. The purpose of the article is the formation of clusters of sections of the electrical network, the initial parameters of which are the main indicators of the quality of electrical energy in accordance with the accepted standards. Total harmonic distortion coefficient of voltages, coefficient of unsymmetry of supply voltages, reactive power of loads are chosen as such parameters. The results of the hierarchical clustering of power supply network sections are summarized in the corresponding dendogram. The method of full connection is used to form a dendogram of sections of the power supply system. This method defines the distance between clusters as the largest distance between any objects in different clusters or the most distant neighbors. The measure of closeness was determined by the Euclidean distance. The obtained treeshaped diagram demonstrates the distribution of the sections of the power supply system into four natural clusters, which visually divides the sections of the power supply system into separate groups according to certain characteristics, namely the main parameters of the quality of the power system. It is shown that the mathematical apparatus of cluster analysis allows solving the problem of classification of sections of the power supply system when the main parameters of the quality of electric energy deviate from the normally permissible values. It is proved that the classification can be carried out not only by one parameter, but also by using a combination of several parameters. The results of the conducted analysis provide an opportunity to further form production rules for the selection of measures to improve the quality of electric energy, which are applied to one or another section of the power supply system.)

Statistical analysis of agro-climatic factors of crop failure of agricultural plots

The article presents an example of a statistical analysis of agro-climatic factors of crop failure in agricultural plots for the cultivation of rice. It is shown that crop failure is mainly due to a variety of random, independent agro-climatic factors: the sum of active temperatures, the sum of precipitation, soil fertility, etc. Agricultural technology of crop cultivation also has a significant impact on crop failure, which is characterized by the following features: the predecessor, the amount of fertilizer, weeding, the number of days from the bay to the discharge of water, the number of days from mowing to threshing. As methods of statistical data processing, the authors use complex data processing by traditional methods, including comparison of mean values of features, principal component analysis, multiple regression analysis, and discriminant analysis. It is noted that the results of complex processing of the agrotechnical characteristics of plots with different rice yields using the apparatus of one-dimensional and multivariate statistical analysis provide a basis only for identifying general trends, since the agrotechnical system has a high level of complexity. For a deeper and more complete penetration into its essence, an apparatus should be used that can identify and take into account the structural heterogeneity of data about this system.

Time-Resolved Kinetic Measurement of Microalgae Agglomeration for Screening of Polysaccharides-Based Coagulants/Flocculants.

Time-resolved monitoring of microalgae agglomeration facilitates screening of coagulants/flocculants (CFs) from numerous biopolymer candidates. Herein, a filtering-flowing analysis (FFA) apparatus was developed in which dispersed microalgal cells were separated from coagulates and flocs formed by CFs and pumped into spectrophotometer for real-time quantification. Polysaccharides-based CFs for Microcystis aeruginosa and several other microalgae were tested. Cationic hydroxyethyl cellulose (CHEC), chitosan quaternary ammonium (CQA) and cationic guar gum (CGG) all triggered coagulation obeying a pseudo-second-order model. Maximal coagulation efficiencies were achieved at their respective critical dosages, i.e., 0.086 g/gM.a. CHEC, 0.022 g/gM.a. CQA, and 0.216 g/gM.a. CGG. Although not active independently, bacterial exopolysaccharides (BEPS) aided coagulation of M. aeruginosa and allowed near 100% flocculation efficiency when 0.115 g/gM.a. CQA and 1.44 g/gM.a. xanthan were applied simultaneously. The apparatus is applicable to other microalgae species including Spirulina platensis, S. maxima, Chlorella vulgaris and Isochrysis galbana. Bio-based CFs sorted out using this apparatus could help develop cleaner processes for both remediation of harmful cyanobacterial blooms and microalgae-based biorefineries.

Development and evaluation of a semi-automatic single-step clean-up apparatus for rapid analysis of 18 antibiotics in fish samples

Here we report a novel semi-automatic pre-treatment apparatus to fulfill a single-step clean-up aim for rapid quantification of 18 antibiotics in fish samples. Trimethoprim and 17 sulfonamides were extracted from fish samples by acetonitrile solution based on ultrasonic-assisted extraction. Cheap analytical filtration syringe (CAFS) clean-up column was used to fulfill single-step clean-up of the extract which was set on the developed semi-automatic clean-up apparatus. This semi-automatic clean-up apparatus is quite convenient for single-step purification by precisely controlling the flow rate of the extracts, in which up to 10 samples can be purified in parallel at one time. The time needed to clean sample was only about 2 min per 10 samples. Type of compatible purification column ranged from 1 mL (inner diameter × length, 5.6 × 55 mm) to 12 mL (inner diameter × length, 15.6 × 83 mm). The apparatus also did not need additional gas source such as nitrogen or air. After purification, the analytes were simultaneously separated and quantified by high-performance liquid chromatography/quadrupole-linear ion trap tandem mass spectrometry (HPLC-QTRAP-MS/MS). The limits of detections ranged from 0.5 to 1.0 μg kg −1 , and the limits of quantifications ranged from 1.0 to 5.0 μg kg −1 . All the recoveries ranged from 81.39% to 116.01%. Intra-day and inter-day relative standard deviations (RSDs) were lower than 14% for all analytes. • A semi-automatic apparatus was developed to fulfill single-step clean-up of the extract. • Up to 10 samples could be purified in parallel at one time. • The flow rate of the extract could be precisely controlled. • The time needed to clean sample was only about 2 min per 10 samples. • The novel apparatus was applied for rapid clean-up of 18 antibiotics in fish.

THE PROBLEM OF CHOOSING THE OPTIMAL DESIGN OPTION FOR A COMPLEX SYSTEM UNDER CONDITIONS OF INTERVAL UNCERTAINTY

The paper describes the process of choosing the optimal design option for a complex technical system under conditions of interval uncertainty and incomplete information about the parameters and the phase state. Problems of this kind are extremely relevant at the initial stage of designing complex systems, when from a variety of possible options it is necessary to select those that are more consistent with the heterogeneous quality criteria and do not always meet the ambiguous preferences of the decision maker.
 The aim of the study is to develop effective methods for comparing various design options for complex systems at the initial design stage under conditions of interval uncertainty. The objectives of the study include the construction of a mathematical model for the functioning of a complex system under conditions of uncertainty, as well as the analysis of the main methods for comparing alternatives with heterogeneous quality criteria.
 Materials and Methods. The article provides a description of the functioning model of a complex technical system under conditions of uncertainty, and also describes the main methods for comparing various options for the system design at the initial stages of design in conditions of incompleteness and uncertainty of information, as well as ambiguity of the preferences of the decision maker.
 Results. The scientific novelty of the implemented approach lies in the use of interval data statistics, which allow the most correct consideration of possible errors associated with measuring the values of the characteristics of the studied technical systems at all stages of the control process.
 The scientific novelty of the implemented approach lies in the use of the interval analysis apparatus, which makes it possible to most correctly take into account the possible errors associated with measuring the values of the characteristics of the studied technical systems at all stages of the design process.
 Discussion and Conclusions. The mathematical model of the process of functioning of a complex technical system under conditions of interval uncertainty developed in the course of the study allows selection of system design options at the initial stages of design, taking into account possible errors and inaccuracies arising from the deviation of values from the calculated nominal values.

Optimizing the Shape of Signals with Quadrature Amplitude Modulation According to the Criterion of Given Reduction Rate of Out-of-Band Emissions

Introduction. The growth in the volume of information transmitted through communication channels leads to their significant congestion. Almost all methods conventionally used to increase the data transfer rate in given frequency bands have been exhausted. In this regard, it is of interest to use new approaches aimed at improving the spectral efficiency of radio engineering and telecommunication systems by applying optimal signals that make it possible to use the bandwidth reserves of transmission channels given by Shannon's theory.Aim. Improvement of the spectral efficiency of digital messaging systems by using signals with a compact spectrum and increased volume of the channel alphabet at the same time as minimizing energy losses.Materials and methods. When searching for optimal signals, the mathematical apparatus of communication theory and functional analysis, as well as the methods of calculus of variations, were used. The evaluation of bit error rate performance of the obtained optimal signals transmitted in a channel with additive white Gaussian noise was performed in the MatLab environment. Results. It was established that, in a channel with additive white Gaussian noise, optimal signals with a signal constellation size of 64 in the case of quadrature amplitude-phase modulation provide an energy gain of more than 1 dB relative to signals obtained by narrowband filtering under the conditions of uncontrolled intersymbol interference. Optimal signals were shown to provide for an energy gain of 4.9 dB with respect to signals based on narrow-band filtering at a fixed spectral efficiency of 7 (bit/s)/Hz.Conclusion. The paper proposes a method for improving the spectral efficiency of quadrature signals with amplitudephase modulation, based on the use of optimal pulse shapes obtained as a result of solving an optimization problem. The optimization problem was solved according to the criterion of minimizing out-of-band emissions with the constraint on bit error rate performance in case of amplitude-phase modulation. The energy and spectral efficiency of signals with optimal pulse shapes and signals based on narrow-band filtering were compared.

Integration of Decay Time Analysis and Radiation Measurement for Quantum-Dot-Based Scintillator’s Characterization

In this study, we demonstrated the process of an integrated apparatus for decay time analysis and gamma radiation measurement with a liquid-scintillator-based cadmium-doped zinc oxide (CZO) nanomaterial. Generally, time-resolved photon counting is an essential analysis method in the field of precision measurement in the quantum domain. Such photon counting equipment requires a pulse laser that can be repeated quickly while having a sharp pulse width of picoseconds or femtoseconds as a light source. Time-correlated single photon counting (TCSPC) equipment, which is currently a commercial product, is inconvenient for recent development research because the scintillator size and shape are limited. Here, neodymium-doped yttrium aluminum garnet (Nd/YAG) laser TCSPC equipment was constructed to analyze the fluorescence characteristics of scintillators having various sizes and shapes. Then, a liquid scintillator added with CZO nanomaterial was prepared and the Nd/YAG laser TCSPC equipment test was performed. As a result of measuring the scintillator using the manufactured Nd/YAG laser TCSPC equipment, the non-CZO liquid scintillator was analyzed at 2.30 ns and the liquid scintillator equipped with CZO-loaded nanomaterial was analyzed at 11.95 ns. It showed an error within 5% when compared with the result of commercial TCSPC equipment. In addition, it was verified that the Nd/YAG laser TCSPC system can sufficiently measure the decay time in nanoseconds (ns). Moreover, it was presented that the Compton edge energy of Cs−137 is 477.3 keV, which hardly generates a photoelectric effect, and Compton scattering mainly occurs.

Cenografia, agenciamento e mundo ético na entrevista em Jogo de cena: uma abordagem discursiva

ABSTRACT Among Eduardo Coutinho’s vast production, the documentary Jogo de cena (2007) stands out and is celebrated as being the centerpiece of the filmmaker's filmography, in which the interviews occupy a central place. The purpose of this article is to reflect upon these interviews, discursively, based on: speech scenes put in perspective and in relation to the aesthetic choices and materiality of the documentary; nature of the interviewer-interviewee relationship, marked by the refusal of an “alleged neutrality” and the production of settings, scenographies, and ethical worlds. For this, we articulated basic concepts of Discourse Analysis, as theorized by Dominique Maingueneau, such as interdiscourse, scenography, setting and discursive ethos. The results demonstrate that it is possible to establish a dialogue between Coutinho’s methodological apparatus and concepts of Discourse Analysis. From a mystical aura of his welcoming silence, the interviewer’s respectful and considerate ethos in relation to the characters' speeches can be inferred.

In-situ copper ion reduction and micro encapsulation of wood-based composite PCM with effective anisotropic thermal conductivity and energy storage

This work develops metallic wood-based phase change materials (MWPCM) with high-performance anisotropic thermal conductivity by impregnating wood with phase change microcapsules and subsequent in situ chemical deposition of copper inside the wood cell lumen. Phase change material (PCM) is encapsulated by polymer to form phase change microcapsules, which solve the leakage problem effectively. Benefited with the well-aligned and hierarchical porous structure of wood, phase change microcapsules coated with copper layer are orderly confined inside wood vessels and fibers, developing a continuous and anisotropic heat transfer network along the highly oriented transport tissues of wood. The morphology, chemical structure and crystallization of microcapsules and MWPCM are investigated using scanning electronic microscope (SEM), flourier transformation infrared spectroscopy (FTIR) and X-ray diffractometer (XRD), and the thermal storage capacity, thermal stability and thermal conductivity of the developed PCM composites are examined using differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA) and laser flash diffusivity apparatus (LFA) respectively. The results show that PCM capsules were effectively accommodated in orderly porous wood as a carrier; the radial and longitudinal thermal conductivity of MWPCM reached 0.37 W/(m*K) and 0.53 W/(m*K), which increased by 362% and 211% compared to pure wood, respectively. The anisotropic thermal conductivity of MWPCM enabled an efficient heat transfer along the longitudinal direction and reduced the heat loss in the transverse direction. MWPCM exhibited good thermal energy storage capacity (92.9 J/g and 94.6 J/g) and suitable phase change temperature (11.4 °C and 29.4 °C) for indoor thermal energy management. MWPCM also displayed outstanding shape-stability, excellent thermal stability and temperature regulation, which has a great potential for building energy collecting, storage and management.

Na2Ca3Si2O8 or γ‐Na2Ca6Si4O15? A hybrid approach combining 3D single‐crystal electron and powder X‐ray diffraction

AbstractPhase assemblages of mixtures containing Na2CO3, CaCO3, and SiO2 in the molar ratio 1:3:2 have been studied at elevated temperatures. Synthesis experiments have been performed at 1000, 1100, and 1200°C within a differential thermal analysis (DTA‐TGA) apparatus. Mass losses during heating and annealing periods of the high‐temperature treatment have been investigated in situ using thermogravimetry. For the run at 1200°C, the solid‐state reactions resulted in almost phase pure polycrystalline material of a previously unknown high‐temperature polymorph of Na2Ca6Si4O15, whose formation was triggered by significant Na2O losses at the reaction temperature. The new so‐called γ‐phase has been structurally characterized by a combination of 3D single‐crystal electron and powder X‐ray diffraction. Basic crystallographic data at ambient conditions are as follows: monoclinic symmetry, space group C 2, a = 17.2066(1) Å, b = 5.47863(3) Å, c = 7.32583(4) Å, β = 91.435(4)°, V = 690.38(1) Å3, Z = 2. Structure solution was accomplished by electron diffraction, whereas the subsequent refinement calculations were based on the Rietveld method using high‐resolution data from a laboratory powder diffractometer. Similar to the other two already known Na2Ca6Si4O15 modifications, the crystal structure of the γ‐phase contains both [Si2O7] dimers and insular [SiO4] moieties. Tetrahedra and [CaO6] octahedra form a three‐dimensional framework whose topological characteristics have been studied. The remaining Ca and Na cations are located on five symmetrically independent positions located in cavities of the network. There are sufficiently strong arguments that previously described “triclinic Na2Ca3Si2O8” is actually misinterpreted γ‐Na2Ca6Si4O15 and that a sodium calcium silicate with a molar ratio of Na2O:CaO:SiO2 = 1:3:2 does probably not exist. Our investigation is an excellent example that 3D electron diffraction has transformed from an exotic technique for crystal‐structure determination into an indispensable method for problems where small sizes of the crystallites is an issue.

Formation of reference trajectories for transformer oil indicators for 330 kV autotransformers

The article describes the procedure of statistical processing of the results of periodic operational tests of transformer oils condition in 330 kV autotransformer tanks with the purpose of forming the reference trajectories of indicators for early diagnosis of transformer oils. The proposed procedure for statistical processing of the results of periodic operational condition tests of transformer oils includes two stages. At the first stage of statistical processing, to reduce the influence of errors characteristic of in-service control, the stationary dependences of transformer oil indicators on the operation time are eliminated according to mathematical expectation. To solve this problem it was proposed to use a mathematical apparatus of single-factor regression analysis of the indicator of oils on the operation time. Practical realisation of such approach has shown that use of the regression analysis allows to reveal not only stationary dependences of oil indicators (that is those dependences for which with growth of operation time no statistically significant change of mathematical expectation of the indicator is observed, that is equivalent to equality to zero of value of angle coefficient of the regression model), but also dependences of oil indicators distorted by a sign of a pair correlation coefficient of oil indicator on operation time. At the second stage of statistical processing the direct formation of reference trajectories of indicators is carried out. To take into account the non-linear nature of the dependences of oil indicators on the operation time and significant differences in the intensity of ageing of transformer oils in individual transformers, due to differences in design and cooling systems of autotransformers, as well as different brands of transformer oils and differences in operating modes of autotransformers, the criterion of maximum correlation of oil indicator on the operation time was used. The use of this criterion allowed to form the reference trajectories of transformer oil indicators in 330 kV autotransformers even in conditions of limited information about operating modes of analysed autotransformers. The given example of practical use of the proposed procedure in the formation of reference trajectories of organic acids content in oil has demonstrated its high efficiency.

Model for assessing the digital maturity of an industrial enterprise

Aim. The work aimed to develop a quantitative model for assessing the digital maturity of an industrial enterprise.Tasks. The work was performed to define the concept of digital maturity of an industrial enterprise; systematize existing approaches to assessing the digital maturity of an industrial enterprise; conduct a critical analysis of existing approaches in terms of taking into account the requirements of the TOGAF corporate architecture levels, the requirements for the reliability of the assessment results; and propose a quantitative model for assessing the digital maturity of an industrial enterprise.Methods. The research tools used in this article include methods of system analysis and synthesis, methods of economic analysis for systematization of existing approaches to assessing the degree of digital maturity of an industrial enterprise, as well as methods of mathematical statistics, econometric analysis for developing a multivariate regression model for assessing the digital maturity of an industrial enterprise taking into account the requirements of the process approach.Results. A classification of models for assessing digital maturity is proposed, which is used to highlight the main approaches to the latter and consider the fields of enterprise activity to assess the level of its digital maturity, assessment scales, methods used in the assessment, and the scope of the models application, as well as the applicability of such models to a comprehensive assessment by levels of the enterprise architecture. A multifactorial regression model for assessing the digital maturity of an enterprise has been developed, which enables to assess the degree of influence of each direction of this assessment on the digital maturity of an enterprise and give recommendations for managing digital maturity, which can be used in the formation of an enterprise digital transformation strategy.Conclusions. The systematization of approaches to assessing the digital maturity of industrial enterprises revealed that the models currently used are mainly based on expert assessments, which leads to subjectivity. These models use nominal and ordinal scales, which makes it difficult to apply the apparatus of econometric analysis. The models described do not take into account the ratio of variables that determine the digital maturity of an enterprise and the levels of its architecture according to the TOGAF method, which results in a “patchwork” nature of considering the business processes of an industrial enterprise and, as a result, the lack of a comprehensive assessment of digital maturity. According to the authors, the incompleteness and subjectivity of the existing evaluation models, as well as the need for their modernization, are obvious. The authors propose a model for assessing the digital maturity of an industrial enterprise, which enables to solve the above problems. The coefficient of determination of the constructed model (R2 = 0.845) indicates that the share of the total scatter relative to the sample average of the integral indicator of digital maturity assessment is 84.5% explained by the constructed regression model. The multiple correlation coefficient (Multiple R = 0.919) indicates the strength of the relationship between the resulting and independent variables. The value of the Fisher criterion (F = 102) indicates the high significance of the constructed multivariate regression model. According to the calculation results, the significant standardized coefficients of the regression equation include Х1 beta, Х3 beta, Х4 beta, Х5 beta, therefore we can conclude that the variation of Х i has the strongest influence on the variation of the resulting attribute Y, when abstracted from the concomitant influence of variations of other factors included in the equation regression.