Objectives. The development and implementation of information and computing architecture and information support for a state central bank digital currency (CBDC) is based on the selection of a software and hardware platform, including technologies and methods for supporting interaction between the elements of the computing complex. The implementation of CBDC technologies significantly depends both on the operational and computing architecture, as well as on the technological characteristics of the means for implementing digital currency information support, which determines the need to develop an appropriate research environment. Thus, the present study sets out to develop an infrastructure for the experimental research environment of the operational and computing architecture used to provide information support for the CBDC.

Methods. Digital technologies required for forming an CBDC implementation stack are under development in many countries of the world. The basis for the formation of a software and hardware complex for providing CBDC information support is comprised of theoretical and experimental studies into contemporary digital transaction management tools.

Results. The main architectural and technological components that make up the CBDC operational and computing environment comprise operational and computing architectures, blockchain technologies, consensus algorithms, and various forms of digital currencies. Five CBDC operational and computing architecture options are presented. Information models of interaction between the participants in transactions of the central bank digital currency were studied with the aim of establishing the effects of an architectural solution to the characteristics of the computing complex used to provide information support. Features of various digital currencies in the form of accounts and tokens were analyzed.

Conclusions. A research environment infrastructure for the CBDC operational and computing information support architecture has been developed. The prerequisites for a comprehensive analysis of the technological characteristics of the CBDC operational and computing environment are set out along with a comparison of operational and computing architecture variants. As a result of the analysis, a summary list of the characteristics of the studied architectures is drawn up. This provides for selecting the optimal operational and computing architecture depending on the requirements imposed on the CBDC.

Objectives. In order to model and analyze the information conductivity of complex networks having an irregular structure, it is possible to use percolation theory methods known in solid-state physics to quantify how close the given network is to a percolation transition, and thus to form a prediction model. Thus, the object of the study comprises international information networks structured on the basis of dictionaries of model predictive terms thematically related to cutting-edge information technologies.

Methods. An algorithmic approach is applied to establish the sequence of combining the necessary operations for automated processing of textual information by the internal algorithms of specialized databases, software environments and shells providing for their integration during data transmission. This approach comprises the stages of constructing a terminological model of the subject area in the Scopus bibliographic database, then processing texts in natural language with the output of a visual map of the scientific landscape of the subject area in the VOSviewer program, and then collecting the extended data of parameters characterizing the dynamics of the formation of links of the scientific terminological network in the Pajek software environment.

Results. Visual cluster analysis of the range of 645-3364 terms in the 2004-2021 dynamics of the memory and data storage technologies category, which are integrated into a total of 23 clusters, revealed active cluster formation in the field of the term quantum memory. On this basis, allowing qualitative conclusions are drawn concerning the local dynamics of the scientific landscape. The exploratory data analysis carried out in the STATISTICA software package indicates the correlation of the behavior of the introduced MADSTA keyword integrator with basic terms including periods of extremes, confirming the correctness of the choice of the methodology for detailing the study by year.

Conclusions. A basis is established for the formation of a set of basic parameters required for an extensive computational modeling of a cluster formation in the semantic field of the scientific texts, especially in relation to simulations of the formation of the largest component of the network and percolation transitions.

Objectives. An urgent task in the context of modern radio and television systems is to improve the quality and quantity of transmitted information. For example, the use of multiple amplitude-phase shift keyed (APSK) signals—16-APSK and 32-APSK—in digital satellite television systems of the Digital Video Broadcasting-Satellite2 (DVB-S2) standard made it possible to transmit 30% more data in the same frequency bands in comparison with the previous DVB-S standard. Such increases in information transmission rates impose more stringent requirements on hardware. An important role in the reception of APSK signals, as well as the signals of other coherent signal processing systems, is played by the stability of synchronization systems. The presence of operational errors can significantly reduce the quality of information reception. The aim of the present work was to analyze the effect of phase and clock synchronization errors on the reception noise immunity of APSK signals with a ring signal constellation structure.

Methods. The study used statistical radio engineering methods informed by optimal signal reception theory.

Results. The effect of phase and clock synchronization errors on the reception noise immunity of APSK signals having a signal constellation ring structure is analyzed. The dependencies of the bit error probability on the magnitude of the phase shift and the clock offset were characterized. The effect of synchronization errors on reception quality were compared with the known results for quadrature amplitude modulation (QAM) signals.

Conclusions. At an acceptable energy loss of no more than 1 dB, the critical phase error can be considered as 2°-3°, while the critical clock error is 3-4%. A coherent receiver of APSK signals is more sensitive to the phase error of reference oscillations than a similar receiver of QAM signals, whereas clock errors have the same effect on the reception quality of these signals.

Objectives. Advances in laser physics over the last decade have led to the creation of sources of single-period electromagnetic pulses having a duration of about 1 ps, corresponding to the terahertz (THz) frequency range and a field amplitude of several tens of MV/cm. This allows the electrode-free application of an electric field to a ferroelectric for observing not only the excitation of coherent phonons, but also ultrafast (at the sub-picosecond timescale) dynamic polarization switching. To detect polarization switching, a pump-probe technique is used in which a THz pulse is used with an optical probe. Since its intensity is proportional to the square of the polarization, the signal of the optical second harmonic is used to measure polarization switching under the action of a THz pulse. To evaluate switching efficiency, both linear (refractive index and absorption coefficient) and non-linear optical characteristics (quadratic and cubic susceptibilities) are required. For any application of ferroelectric crystals in the THz range, knowledge of the relevant linear optical characteristics is also necessary.

Methods. The technique of THz spectroscopy in the time domain was used; here, a picosecond THz pulse transmitted through the crystal is recorded by strobing the detector with a femtosecond optical pulse. The THz-induced dynamics of the order parameter in a ferroelectric was studied by detecting the intensity of a nonlinear optical signal at the frequency of the second optical harmonic.

Results. The transmission of a THz wave and the intensity of second harmonic generation on a lead germanate crystal doped with silicon in the time and spectral domains were measured. On this basis, the absorption coefficient dispersion and cubic nonlinear susceptibility were calculated in the range of 0.5-2.0 THz. The presence of a region of fundamental absorption near the phonon modes was confirmed along with a resonant enhancement of the cubic nonlinear susceptibility for two phonon modes Ω₁ = 1.3 THz and Ω₂ = 2.0 THz.

Conclusions. The proposed technique is effective for analyzing the dispersion of the optical characteristics of ferroelectric crystals. The significantly improved spectral resolution (0.1 THz) increases the accuracy of determining nonlinear susceptibility due to the detailed analysis of the linear and nonlinear contributions to the second harmonic intensity.

Objectives. The basic element of a field-programmable gate array is a lookup table (LUT). While in canonical normal form LUTs generally implement only one logical function for a given configuration, in this case, there is always an inactive pass transistor element. Moreover, using a single LUT for a single function reduces system-on-a-chip (SoC) scalability. Therefore, the purpose of the present work is to develop a LUT structure for implementing several logic functions simultaneously on inactive transmitting transistors.

Methods. The evolution of LUT structure is presented for three variables, in which the number of simultaneously implemented functions increases. To implement additional functions, the logical device was decomposed with a different number of variables. The structures were modeled in the Multisim electrical simulation system.

Results. The presented simulation of more than two logic functions on inactive parts of the LUT shows the simultaneous operation of two and four logic functions. The complexity for a different number of variables and number of implemented functions is compared.

Conclusions. The simulation results demonstrate the operability of LUT structures in which several logical functions are performed. Thus, when implementing additional functions in the new structure, a smaller number of transmitting transistors is required as compared to a conventional LUT, thus increasing device functionality. The presented solution can be used to increase the number of simultaneously implemented functions of the same variables, which can be important e.g., when implementing code transformations.

Objectives. The wear monitoring of metal structural elements of power plants—in particular, pipelines of nuclear power plants—is an essential means of ensuring safety during their operation. Monitoring the state of the pipeline by direct inspection requires a considerable amount of labor, as well as, in some cases, the suspension of power plant operation. In order to reduce costs during monitoring measures, it is proposed to use mathematical modeling. This work aimes to develop a mathematical model of a diagnostic system for assessing the probability of detection of defects by solving inverse problems.

Methods. A binomial model for assessing the reliability of monitoring, comprising the Berens-Hovey parametric model of the probability of detection of defects and a parametric model based on studying test samples, was analyzed. As an alternative to this binomial model, a computational method for assessing the reliability of non-destructive testing systems by solving an inverse problem was proposed. To determine the parameters of the defect detection probability curve, the model uses data obtained by various monitoring teams over a long period of power plant operation. To serve as initial data, the defect distribution density over one or more of the following characteristics can be used: depth, length, and/or cross-sectional area of the defect. Using the proposed mathematical model, a series of test calculations was performed based on nine combinations of initial data. The combinations differed in the confidence coefficient of the initial monitoring system, the parameters of the distribution of defects, and the sensitivity of the monitoring system.

Results. The calculation data were used to construct curves of the probability density of detected defects as a function of the defect size, recover the values of the defect distribution parameters under various test conditions, and estimate the error of recovering the parameters. The degree of imperfection of the system was estimated using the curve of the detection probability of a defect by a certain monitoring system.

Conclusions. Under constraints on the data sample size, the proposed methodology allows the metal monitoring results to be applied with greater confidence than currently used methods at the same time as evaluating the efficiency of monitoring carried out by individual test teams or laboratories. In future, this can be used to form the basis of a recommendation of the involvement of a particular team to perform diagnostic work.

Objectives. Processes of energy transfer in solids and resultant thermal loads are widespread in nature and technology. This explains the scientific and practical significance of constructing a theory of these processes, as well as developing effective methods for studying the modeled concepts developed on this basis. The purpose of such studies is to determine basic flux patterns of complex processes occurring especially under conditions of powerful energy impacts in various technological operations. These include plasma-chemical processing of materials, their processing in infrared furnaces and solar plants, intense heating of materials carried out by laser or electron beams, and the use of powerful radiation emitters for thermal hardening and hardening of the surface of products. In these cases, the phenomenon of thermal shock arises, forming one of the central topics in thermomechanics and strength physics of solids. The present work considers an open theoretical problem of thermal shock in terms of a generalized model of dynamic thermoelasticity under conditions of a locally nonequilibrium heat transfer process. Depending on the type and curvature of the boundary surface of the considered massive body, the model can be used to study the problem in three coordinate systems: cartesian coordinates—a massive body bounded by a flat surface; spherical coordinates—a massive body with an internal spherical cavity; cylindrical coordinates—a massive body with an internal cylindrical cavity. Three types of intensive heating are considered: temperature heating, thermal heating, and heating by medium. Following the development of an analytical solution, the results of conducted numerical experiments are presented along with their physical analysis.

Methods. The study applies methods and theorems of operational calculus according to the theory of special functions.

Results. Generalized model representations of thermal shock are developed in terms of dynamic thermoelasticity for locally nonequilibrium heat transfer processes simultaneously in three coordinate systems: Cartesian, spherical, and cylindrical. The presence of curvature of the boundary surface of the thermal shock area substantiates the initial statement of the dynamic problem in displacements using the proposed corresponding “compatibility” equation.

Conclusions. A generalized dynamic model of the thermal reaction of massive bodies with internal cavities simultaneously in Cartesian, spherical, and cylindrical coordinate systems under conditions of intense temperature heating, thermal heating, and heating by medium is proposed. The model is considered in terms of displacements based on local nonequilibrium heat transfer. A numerical experiment carried out according to the obtained analytical solution for stresses forms a basis for a description of the wave nature of the propagation of a thermoelastic wave. A comparison with the classical solution is made without taking into account local nonequilibrium. The calculation of engineering relations carried out on the basis of the operational solution of the problem is important in practical terms for the upper estimate of the maximum thermal stresses.

Objectives. The paper aimed to review and analyze the results of works devoted to numerical modeling of experiments on the interaction of high-power ultraviolet (UV) laser pulses with condensed targets. The experiments were carried out at GARPUN, the powerful KrF-laser facility at the P.N. Lebedev Physical Institute of the Russian Academy of Sciences (Moscow). The relevance of the research is related to the use of excimer UV lasers as a driver for a thermonuclear reactor. Physical aspects of laser-plasma interaction, including those related to the possibility of using two-sided cone target in a fission-fusion reactor, are discussed.

Methods. The research is based on physico-mathematical models, including Euler and Lagrange.

Results. The mathematical modeling of three types of natural experiments is presented: (1) burning through different thicknesses of Al foils by high-power UV laser; (2) studying hydrodynamic instability development at the UV laser acceleration of thin polymer films and features of turbulent zone formation; (3) interaction of high-power UV laser pulses with two-layer targets (Al + Plexiglas) and study of fine structures. Numerical modeling showed that a hybrid reactor with UV laser driver can use targets in the form of two-sided counter cones.

Conclusions. Physico-mathematical models are developed along with 2D codes in Lagrangian and Eulerian coordinates as confirmed in the results of natural experiments. The models can be used to describe the physics of high-power UV laser pulses interacting with various targets and forecast the results of reactor-scale experiments.

Objectives. The purpose of this work was to create a special entrance test for first-year students starting to learn a new foreign language. To achieve the research objective, the study analyzed data on testing language/linguistic proficiency and motivation for learning a foreign language. A range of test parameters identifying both abilities and motivation to learn a foreign language in general, but not related to learning a specific language, were highlighted. The identified parameters were used to inform a questionnaire tested on a group of students, whose level of abilities and motivation had already been ascertained. The findings about students were compared with the already known empirical data to support the improvement of test items.

Methods. To describe a special entrance test for first-year students starting to learn a new foreign language in a non-humanities higher education institution, a test technology for identifying certain cognitive, psychological, intellectual, motivational characteristics of a student's language personality was created. The developed test parameters served as the basis for constructing several heterogeneous test blocks.

Results. The initial version of the test obtained was verified by pilot testing first-semester-first-year students. Expert assessments of the foreign language potential learning on the part of students were used to evaluate the reliability and validity of the test. A subsequent correction of tasks and responses was carried out in light of the verification results.

Conclusions. A recommendation to conduct this kind of testing prior to the first semester with the aim of forecasting the success of foreign-language educational activities of students enrolled in the foreign language study group from the “starter” level is formulated. The results of such diagnostics can be used to draw up personified adaptive training programs within the educational process.