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Ensembles of InAs quantum dots with a very low density (~10⁶ cm⁻²) are grown by molecular beam epitaxy, which allows the spectral characteristics of emission of single quantum dots to be studied by the method of cryogenic microphotoluminescence. With increasing quantum dot size, the splitting of exciton states is demonstrated to increase steadily to ~10² µeV. In the exciton energy range of 1.3–1.4 eV, the magnitude of this splitting is comparable with the natural width of the exciton lines. This result is important for the development of emitters of entangled photon pairs based on InAs quantum dots.

Surface-enhanced Raman scattering by optical and surface phonons in CdS, GaN, and CuS nanocrystals, and AlN nanowires is detected and studied. It is found that the presence of metal (Ag, Au, and Pt) nanoclusters noticeably modifies the Raman spectra of the nanostructures and results in a resonant increase in the intensity of optical phonon modes in CdS and CuS nanocrystals or in the emergence of surface modes in GaN nanocrystals and AlN nanowires. It is shown that the frequencies of the surface optical phonon modes of the examined nanostructures are in good agreement with the theoretical values calculated within the framework of the dielectric continuum model.

The time of spin relaxation of excitons in (In,Al)As/AlAs quantum dots with an indirect bandgap and type-I band alignment is determined by measuring the dynamics of photoluminescence circular polarization induced by a magnetic field B. The spin relaxation time τ_S increases with decreasing magnetic field in proportion to B⁻⁵; its value is ~40 µs in a magnetic field of 6 T at a temperature of 1.8 K. As the temperature T increases in a magnetic field of 7T, the value of τ_S decreases as T^−1.1. The character of the dependences of τ_S on the magnetic field and temperature evidences that spin relaxation of excitons is provided by a process with participation of one acoustic phonon.

Nanowire (NW) detection is one of the fast and highly sensitive methods. An NW biosensor based on silicon-on-insulator (SOI) structures are used in the reported study for real-time label-free biospecific detection of the NFATc1 (D-NFATc1) cancer marker. For this purpose, the SOI NWs are functionalized with NFATc1 aptamers used as macromolecular probes. It is demonstrated that such a biosensor can ensure a detection limits up to 10⁻¹⁵ M, which is comparable with the sensitivity ensured by an NW biosensor with immobilized antibodies used as macromolecular probes. The results of this study demonstrate that such approaches to the development of sensor elements for highly sensitive diagnostics of diseases are really promising.

A method is proposed to solve the joint optimization problem based on system quality criteria for the thermophysical processes of preheating and subsequent plastic deformation of metal semi-finished products in industrial metal working systems with a free choice of the admissible initial temperature states before plastic deformation that integrate these processes in a single process system. Potentials for practical applications of the method is illustrated by the example of a process system for forming pressed articles from aluminum alloys.

A problem of control of quadrotor vehicle motion over a trajectory defined implicitly in the coordinate space is considered. The previously proposed system of automated control of quadrotor vehicle flight is supplemented with relations based on an extended Kalman filter for estimating the plant state vector and the systematic error of measurements. The workability of the control system in the presence of the measurement noise is verified by results of modeling and experiments with the AR.Drone quadrotor vehicle.

An algorithm for the analytical synthesis of reduced-order observers for dynamic systems with an output matrix of arbitrary form is proposed, and invariance conditions for the constructed observer with respect to external disturbances are formulated. Solvability conditions for the synthesis problem are obtained in the form of a system of linear matrix equations. The proposed algorithm is based on a nondegenerate transformation of the state vector using the matrix canonization technique and methods for solving linear matrix equations of arbitrary dimension.

In this paper, we consider typical problems of automatic control for systems consisting of a carriage and a one-link inverted pendulum: stabilization of the pendulum in the absence of constraints on the coordinates of the carriage, control of the speed and position of the carriage with the stabilization of the pendulum, and control of the position with the subordinate system of speed control. Control algorithms were synthesized using a signal-adaptive inverse model based on the requirement of the desired distribution of the poles of the linearized zero system with deliberate implementation of threerate processes. The results of numerical simulation of the synthesized control systems are presented.

A servo model is developed and its parameters are identified using data obtained on a test bench developed. High accuracy of the proposed model is confirmed experimentally.

Two important stages in design of fuzzy approximators, including structure generation and parameter optimization, are considered. Two optimization criteria, i.e., the accuracy measured by the root-mean-square error and the complexity expressed as the number of fuzzy rules, are proposed. The results of studies of the approximators obtained on real data from the KEEL repository are given, and the results are compared with their analogs.