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The emergence of magnetic properties in nano-objects of non-magnetic substances based on silicon and transition metal (iron) is considered. An analysis of the literature showed that, for a monolayer iron coating on a vicinal silicon surface with (111) orientation after solid-phase annealing at 450-550 °C, a system of self-ordered two-dimensional nanorods with the α-FeSi₂ structure is formed, which has superparamagnetic properties. In this work, we study the transition to ferromagnetic properties in a system of α-FeSi₂ nanorods in the temperature range of 2-300 K with an increase in the iron coverage to 5.22 monolayers, which is important for creating spintronics devices in the framework of the planar silicon technology.

In this paper the procedure of the controller synthesis for a linearized system “double inverted pendulum on a cart” based on the sliding modes technique is described. The main peculiarity of this method is the two-stage controller calculation. At the first stage, the canonical basis transformation of the model object is performed, and the control algorithm is organized in the form of a function of canonical variables. At the second stage, the controller definition related to the initial basis is obtained via the inverse transformation of variables. As the direct measurement of several internal variables for the type of the object under research is possible, it is needed to estimate the remaining object variables for the controller implementation. The use of several state estimation filters of the same kind is proposed for this purpose, which allows definition of the entire state vector, although only some of state variables can be measured directly. The calculated controller ensures pendulum stabilization in the upper position with the low value of angle deviation from the vertical. The results of the numerical simulation of the system with the help of the MatLab Simulink integrated environment illustrate the main properties of the system.

The paper proposes a way to apply the shuffled frog leaping algorithm as a tool to expand a rule base of the fuzzy classifier. Its application is relevant in the case where the existing rules are not sufficient for the qualitative recognition of all classes, for example, in the presence of data imbalance. Additional rules generated by metaheuristics are able not only to improve the classification quality, but also to provide a more complete description of the domain under study. To create a compact initial structure of the classifier, the algorithm based on extreme values of features in classes is used. The combination under consideration is tested on 36 imbalanced datasets from the Knowledge Extraction based on Evolutionary Learning repository and showed an increase in the mean geometric accuracy on 34 datasets, as well as satisfactory results compared to analogs. The advantages of the proposed algorithm of structure formation are the absence of the necessity of data augmenting with synthetic samples, low scatter of results in individual runs, and the ability to improve the classification quality by adding a few rules.

Fundamental research of basic creating mosaic focal plane arrays (MFPAs) allowed to optimize the prototype of mosaic technology with decreasing "blind zones". At the same time, minimal damage areas are provided at the edges of the crystals after separating the wafers with the achievement of minimum gaps between crystals of adjacent submodules up to a value of no more than 2-3 microns for different determining materials. The parameters of infrared MFPAs are investigated depending on the wavelength of the maximum spectral characteristic of the photosensitivity of multilayer structures with quantum wells, on the pitch of quantum well photodetectors and on the format of submodules. In a series of the proposed variants of technological prototypes, the "blind zones" of the MFPA are optically overlapped and the ultimate, 100%, image-conversion efficiency is provided. The mosaic technology is one of the fundamental principles of achieving ultra-high dimension of the MFPAs with maximum image-conversion efficiency.

On the basis of the previously developed mathematical model and algorithms for functioning of the mirror system control system of the Millimetron Observatory, the results of numerical simulation of obtaining permissible values of the errors of the on-board 3D scanner during the preliminary measurement of the geometric parameters of the spatial location of the mirror system of the Millimetron Observatory using optical control marks on the surface of the mirror system are presented. When modeling the measurement of the geometric parameters of the spatial arrangement of the control marks, two options for their execution on the panels of the main mirror of the telescope are considered: Option 1 - the control marks are given in the form of mirror spheres with a diameter of 10 mm, located at the four corners of the panels of the main mirror; Option 2 - the control labels of Option 1 are complemented with miniature swivel mirrors. The miniature mirrors allow the measuring beam to be rotated so that through the mirror it is possible to measure the geometric parameters of the control marks located on adjacent (for mirrors) panels of the main mirror. It is revealed that, when the permissible values of errors in the operation of the 3D scanner are reached (9 μm for the rangefinder channel and 2 angular sec for the angle channels) and combined control marks are used (option 2), it is potentially possible to build a device for pre-tuning the mirror system.

Micromilling technologies are used to design and experimentally study terahertz power reflecting optical elements with free-form surfaces. The results of the experimental study are in good agreement with theoretical estimates. It is shown that the technique used in this paper makes it possible to develop terahertz focusing reflecting elements with energy efficiency above 94 %.

Among other problems, systems of space monitoring of the near-Earth space include detection of moving low-contrast objects in images with a powerful spatially unstable background significantly exceeding random (in most cases, weakly correlated) noise. The most effective method of increasing the signal-to-noise ratio under the conditions of different velocities of the objects and background is interframe processing of a sequence of images, which ensures suppression of the background component in the current frame by means of subtracting its estimate obtained from the previous frames. The problem is the presence of a priori unknown motion of the background, leading to significant errors in estimate formation in the regions of sudden changes in the background velocity. The algorithm of interframe processing is studied, which allows one to estimate moderate local motions of the background and to compensate for them down to fractions of the sampling step. Results of full-scale modeling are presented, which demonstrate the possibility of background component suppression down to the noise level even in regions with drastic changes in the background.

Within the framework of ensuring conditions for the normal operation of photoreceiving diode matrices, the influence of the step profile of a composition on the formation of inversion in cadmium - mercury - tellurium (CMT) films under the action of an embedded charge Qi of an insulating dielectric is studied. The problem of the maximum permissible value of Qi, which does not yet form inversion in the system, is analyzed by varying the system parameters: the values of rupture of the zone edges for charge carriers in the CMT, the thickness of the broadband surface CMT layer, temperature, and the doping level of the two-layer CMT film

Waveguide microstructures based on strained silicon with the use of carbonitride and silicon nitride films as cladding layers are created. A plasma-enhanced chemical vapor deposition technique is developed, which allows obtaining high values of intrinsic mechanical stresses (about 700 MPa). The strained waveguide structures are characterized by micro-Raman spectrography during a scanning procedure. It is demonstrated that deposition of carbonitride and silicon nitride films induces compressive stresses in the silicon waveguide, which is proved by the shift of the maximum of the main peak of scattering on LO-phonons of silicon toward higher wave numbers. The compressive stresses in the silicon waveguide clad with silicon nitride and carbonitride layers are estimated as 350 and 250 MPa, respectively, which is sufficient for the emergence of nonlinear optical properties of silicon (Pockels effect)

This paper presents the results of the development and testing of a complex for studying the operating modes of CCD sensors. The purpose of the study is to verify the performance of these matrices as part of a gated-viewing system without using an image intensifier or other external high-speed gate in its design. The complex allows one to control a commercial CCD sensor by an undocumented method using signals of arbitrary shape, synchronize its operation with a laser emitter, receive and digitally process an image and transfer it to external devices. Conducted experiments on various CCD sensors have shown that the possibility of designing a gated-viewing surveillance system based on an interline transfer CCD sensor without using an image intensifier and the possibility of practical application of such a system