Objectives. The ever-increasing demands on the technical parameters of microwave radio transmission devices necessitate a search for ways of improving their efficiency and reliability, as well as means for reducing their weight and size parameters. Since such requirements largely relate to secondary power supplies, the present work set out to develop secondary power supplies for the cathode heating and bias circuits of a floating-drift multibeam klystron capable of operating at a high potential of the klystron cathode and providing stable voltage in all operating modes.Methods. In order to calculate the parameters of the resonant circuit, the first harmonic approximation method is used.Results. Approaches for designing secondary supplies are described along with the method for developing the cathode heating and bias supplies for a floating-drift multipath klystron. The calculation method used for testing the design of the transformer windings is presented. The design avoids the use of chokes as separate elements by integrating them inside a magnetic system and providing isolation by high potential of the secondary winding. The results of testing the power supply using complex test bench waveforms are given along with the main obtained parameters. The operation of the power supply is demonstrated in switching mode at zero voltage for the minimum, nominal, and maximum input voltages in the range of the inductive resistance of the circuit when the voltage phase precedes the current phase.Conclusions. The calculated efficiencies of the presented cathode heating and bias supplies are 85% and 92%, respectively. The developed supplies, which have smaller dimensions than their transformer analogues, allow a stable output voltage to be maintained when the input voltage varies, while the use of the soft start method allows the life of the klystron to be extended.

Objectives. The object of the research is to study citation information networks structured on the basis of a sample from the arXiv database related to theoretical high energy physics (high energy physics, HEP). Since 1974, this database has indexed more than 500000 articles, including their complete citation trees. The paper proposes a method for detecting percolation transitions in the dynamics of cluster formation of articles with similar content. Improving the accuracy of information cycles in knowledge networks can help resolve applied problems related to the quality of scientometrics and its indicators.Methods. An optimized algorithm for dynamic network separation in the Pajek software environment was applied, in order to detect the emergence of a largest component equivalent to a percolation transition. This approach enables a detailed study of dynamic and general parameters to be carried out in each reduced network with a given time step. The clustering algorithm combines citation structure and temporal information about data.Results. It was found that a percolation transition occurs in the HEP network. The indicator of this transition is the formation of a largest component near the critical point which occurs at the 10th month of the time sample interval. At the same time, a generalized conclusion about the behavior of network parameters shows a positive trend in the growth of connectivity for the entire time period (from 1991 to 2003). Furthermore, a generalized analysis of citation distribution reveals eleven laureates of highly cited articles who set the basic vector for development in the field of HEP. It is worth noting that the prominent scientists from the top three in terms of citations are linked by a shared field of research: string theory. Verification of this fact confirms that our citation evaluation method is effective. Determining the characteristics of the HEP (high-energy physics) network enables an important indicator of the researcher’s activity and behavior to be identified.Conclusions. In the column of authors linked by co-authorship, of the 9200 authors in the HEP physics community, 7304 belong to a single connected component. The temporal nature of citations indicates a rapid uptake and understanding of relevant new work. Percolation transitions, which are indicators of sudden conceptual shifts in citation networks, allow us to identify and link articles into research schemes which form clusters of new ideas and theories.

Objectives. The study set out to develop fundamental methodological principles for the logical integration of information systems (IS) in organizations and to quantitatively assess the topological significance of the IS integration process.Methods. Methods based on expert systems were used for the logical integration of information in conjunction with data-mining approaches based on various IS. In order to quantitatively assess the topological significance of the IS integration procedure, graph theory methods were used. Discrete topology methods were also employed for calculating the topological invariants of the IS interconnection topology.Results. Issues and challenges involved in the integration of IS in large organizations are considered in terms of integration methods based on physical and logical principles. While IS integration approaches based on logical principles offer distinct advantages over physical integration approaches, new problems arising in the context of logical integration approaches require innovative solutions. The proposed scheme for the logical integration of IS includes an algebraic method for quantitatively assessing the topological significance of integration, comprising an important numerical indicator in the logical integration of IS. Methods based on learning expert systems, which represent a fundamental solution for organizing the logical integration of IS for intelligent data analysis, are reviewed.Conclusions. When integrating IS in organizations, it is advisable to use a logical integration approach that preserves the logic of existing information systems. The application of logical integration enables intelligent data analysis using various IS. The use of expert systems in logical integration enables the creation of a new logical layer for providing decision support within the organization.

Objectives. Recently studied phenomena in condensed matter physics have prompted new insights into the dynamic theory of crystals. The results of numerous experimental data demonstrate the impossibility of their explanation within the framework of linear models of the dynamics of many-particle systems, resulting in the necessity to account for nonlinear effects. Analyzing the dynamics of systems in condensed matter physics containing a sufficiently large number of particles shows that modes of motion can undergo changes depending on the potential of interparticle interaction. This is also reflected in the presence of domains with essentially chaotic phase space having a number of degrees of freedom N ≥ 1.5 and a certain set of interparticle interaction parameters. However, it is not only the dynamic model that appears to be strongly nonlinear. A similar nature of motion can be also observed in a static nonlinear many-particle system. The paper aims to study the influence of the external field specified by the interatomic triple-well potential on the equilibrium structure of a chain of interacting atoms.Methods. Methods of Hamiltonian mechanics are used.Results. Analytical expressions are obtained and analyzed for determining the phase portrait of the equilibrium structure of a chain of interacting atoms for various values of the parameter characterizing the local potential of the field in which each atom of the chain moves. Phase portraits of the equilibrium structure of the system are constructed in continuous and discrete representations of the equilibrium equations for various values of the parameter characterizing the local potential of the field in which each atom of the chain moves.Conclusions. It is shown that both periodic and random chaotic arrangements of atoms are implemented depending on the magnitude of the external field.

Objectives. When measuring the transverse Kerr effect on thin-film structures, interference effects have a great influence on the result obtained. In conference presentations, some researchers have reported on the use of white light in experiments. In their opinion, despite the thickness of the studied layers being much less than the wavelength of light, white light can help avoid interference effects and/or resonant excitation of plasmon waves. The aim of the present work is to verify the validity of such statements using simulation.Methods. In order to solve this problem, the method of computer simulation was used. A numerical solution of equations was compiled for a model structure for various thicknesses and materials of layers.Results. The simulation results show that interference effects in different parts of the spectrum when using white light sources do not neutralize each other. The magnitude of the effect is affected not only by the thickness of the structure layers, but also by the shape of the source emission spectrum, as well as the sensitivity curve of the photodetector. In this case, the output of the measured value of the effect to a plateau at relatively large thicknesses of the magnetooptical film is due to the light being absorbed in the thickness of the magneto-optical film and is negligibility of the back reflection of light from the substrate.Conclusions. The presented technique takes into account the influence of interference effects when measuring the equatorial Kerr effect in white light or using other sources having a wide spectral range, thus improving the interpretation of experimental results. The results are relevant to the development and research of the physical foundations for creating new and improving existing devices in micro-, nano-, and solid-state electronics, as well as quantum devices, including optoelectronic devices and converters of physical quantities.

Objectives. One of the main tasks of radiolocation involves the problem of increasing spatial resolution of the targets in the case of limited aperture of the radar antenna array and short length of time samples (snapshots). Algorithms must be developed to provide high angular resolution and low computational complexity. In order to conform with the existing Advanced Driver Assistance Systems requirements, modern cars are equipped with more than one radar having a common signal processing scheme to improve performance during target detection, positioning, and recognition as compared to a single radar. The present study aims to develop a two-dimensional Direction-of-Arrival algorithm with low computation complexity as part of distributed coherent automotive radar system for cases involving short time samples (snapshots).Methods. A virtual antenna array formation algorithm is formulated according to the two-dimensional Capon method. A proposed modification of two-dimensional Capon algorithm is based on sequentially estimating the directions of arrival for the distributed radar system. The Monte Carlo method is used to compare the effectiveness of the considered algorithms.Results. The 2D-DoA sequential algorithm of azimuth and elevation estimation is proposed. The comparative analysis results for the developed algorithm and classical 2D Capon method based on numerical simulation using Monte Carlo method are presented. The proposed scheme of DoA estimation for coherent signal processing of distributed radars is shown to lead to an improvement of the main considered metrics representing the probability of correctly estimating the number of targets, mean square error, and square error compared to a single radar system. The proposed low-computational algorithm shows the gain in complexity compared to full 2D Capon algorithm.Conclusions. The proposed two-stage algorithm for estimating the directions of arrival of signals in azimuth and elevation planes can be applied to the distributed system of coherent radars with several receiving and transmitting antennas representing multiple input multiple output (MIMO) radars. The algorithm is based on sequentially estimating the directions of arrival, implying estimation in the azimuthal plane at the first stage and estimation in the vertical plane at the second stage. The performance of a coherent radar system with limited antenna array configuration of separate radar is close in characteristics to a high-performance 4D-radar with a large antenna array system.

Objectives. The high demand for unmanned aircraft and their efficiency makes the production of their components a matter of relevance. One of these components is the speed controller of the brushless electric motor of the propeller motor group. At the current time, Russian industry, however, does not mass-produce them. In order to start production, control methods and algorithms for the hardware and software parts of devices of this type are needed. Criteria for selecting the main components also need to be formalized. The aim of this work is to develop a method for the software control of electric motors. This includes block diagrams and invariant algorithms and methods for the calculated selection of parameters of the main microcontroller of the electronic speed controller.Methods. Methods of algorithmization, expert assessments, linear computational processes and experimental studies were used.Results. The paper presents the theoretical basis for controlling the required motors. It proposes a block diagram of the implementation of the controller, and a technique for switching windings when controlling with a trapezoidal signal is proposed. Examples are given in the form of an oscillogram. Based on theoretical research, an invariant algorithmic apparatus was developed for building software for various types of microcontrollers. Block diagrams of all the main modules of the software are also presented. The main ones include: the event switching algorithm; and the main endless loop of the microcontroller. The requirements for microcontrollers to create the various types of speed controllers are formalized herein and presented in the form of a set of mathematical expressions. They enable the number of required peripheral devices and microcontroller ports to be calculated according to the requirements for the microcontroller, as well as the computing power of the core used.Conclusions. Experimental studies show the reliability of the theoretical research presented herein. The results obtained can be used to select the optimal element base and develop software for speed controllers of electric motors of the propellers of unmanned aircraft.

Objectives. The work analyzes features of one of the most promising approaches to solve the problems for motion planning of autonomous robotic manipulators of various types and purposes using the rapidly exploring random tree (RRT) method. The development of modern robotics is shown to be inextricably linked with the improvement of the designs of the created samples, for which the placement of a manipulator on platform becomes a typical layout option. Prospects for using the RRT method as a constructive basis for creating a universal motion planner are evaluated for mobile and robotic manipulators, including autonomous robotic systems with a manipulator on a moving platform.Methods. The object of the research is the RRT method and its well-known modifications RRT* and RRT-Connect. The effectiveness of applying such methods for solving problems associated with planning the motions of robotic manipulators of various types was evaluated using computer and natural simulation methods.Results. Based on a review of the literature and the results of the research, the wide possibilities of the RRT method can be used for solving motion planning problems not only for mobile and robotic manipulators, but also for robotic systems on whose transport platform an onboard manipulator has been installed (including those having a redundant or reconfigurable structure). The effectiveness of the applied application of the RRT method is confirmed by examples of modeling a mobile platform with an onboard manipulator and the results of full-scale experiments with a prototype of the ARAKS reconfigurable mechatronic-modular robotic manipulators (RTU MIREA, Russia). It can be experimentally demonstrated and theoretically substantiated that the final dimension of the exploring tree, and hence the time of its construction up to reaching a given target state, is largely determined by the value of the growth factor.Conclusions. The generalization of the results obtained opens up real prospects for using the RRT method as a constructive basis not only for creating universal means for motion planning mobile robotic systems with an onboard manipulator, but also for solving the problems of automating the docking of autonomous mobile platforms.