A metal-dielectric narrow-band filter for a wavelength of 270 nm is designed within the framework of the conductive surface model to characterize the properties of thin metal films. It is demonstrated that inclusion of four thin molybdenum films into a multilayer dielectric structure ensures effective cut-off of the transmission at <1.5% in the visible range of the spectrum with the maximum transmittance

The existence of internal structural defects in gas insulated combinations (GIS) seriously affects the normal operation of equipment, and it needs an efficient and non-destructive detection method. This study is focused on the feasibility of X-ray digital imaging detection in GIS equipment monitoring. First, the digital imaging detection process is briefly introduced. Then, in order to obtain high-quality

In this paper, we consider two-signal and modified two-signal methods for measuring the S-parameters of passive two-ports and a method for adequately measuring the S-parameters of two-ports, such as transistors, developed on their basis. The methods are implemented using a coaxial simulator-analyzer of microwave amplifiers and oscillators in its measuring channels matched or mismatched with loads.

A control method and software structure for solving the problem of control of motion of a group of robots along a prescribed trajectory with preserving a chosen configuration under conditions of unsteady dynamic characteristics of individual robots is proposed.

Based on an analysis of differences between the experimentally measured temperature dependence of the current-voltage characteristic (I-V curve) of a laser diode bar (LDB) with AlGaAs/GaAs heterostructure and the dependence obtained in accordance with the well-known model of light-emitting diodes, assumptions were made about the sources of these differences. The agreement between the experimental and

In this paper, we propose a solution to the problem of designing a combined output control system for a nonlinear nonaffine plant with a delay in the control loop under a priori parametric uncertainty and external interference. Simulation results confirm the performance of the control system, and the resulting controller provides tracking of the plant to the reference signal.

A diffraction Fresnel method of precision measurement of diameters of circular metallic cylinders in the range from several units to hundreds of millimeters with an arbitrary coefficient of light reflection from the cylinder surface is developed. The method is based on determining the position of the first maximum in the Fresnel pattern of the object formed in the free space. An expression for the

A method of fast bandwidth selection in a nonparametric algorithm of pattern recognition corresponding to the maximum a posteriori probability criterion is proposed. The algorithm is based on the results of studying the asymptotic properties of the nonparametric estimate of the separation surface equation and probability densities in solving a two-alternative problem of pattern recognition. The proposed

A classifier for operation with 1-pixel image fragments is proposed. Element segmentation into object and background is performed based on posterior probabilities, which are calculated using a histogram. A simulation experiment has shown that the developed algorithm provides a more accurate classification than segmentation based on the brightness threshold determined from the minimum condition for

Reconstruction of a wavefront containing turbulent distortions of optical radiation is considered. The Hartmann method based reconstruction is carried out using the wave function approximation by Zernike polynomials according to estimates of local slopes and analyzed on the basis of filling Hartmannograms with focal spots, depending on the telescope design. The volume and quality of information about

Influence of nonlocality on the polarization dynamics of an electric field pulse in a medium with cubic nonlinearity is under study. Nonlinear equations are solved using a variational approach. It is shown that nonlocal and chiral effects cause trajectory oscillations and nonlinear polarization rotation of soliton pulses of the field.

Nanowire SOI biosensors are used to detect the Ebola virus VP40 protein by identifying its immune complexes with specific monoclonal antibodies (MCAs). It is shown that the reaction of specific interaction between VP40 and MCAs causes a more pronounced biosensor response than direct adsorption of VP40 or antibodies to their surface. The formation of antigen — antibody complexes leads to the accumulation

Several approaches to the use of neural networks for object detection on spatially inhomogeneous backgrounds are considered. A method for constructing a classifier for object detection directly from observed fragments has been developed. An approach consisting of a combination of matched linear filtering and convolutional neural networks is proposed. It is shown that this approach reduces the false

Application of the method of layer-by-layer selective laser sintering of a metal powder for depositing capillary-porous coatings with a prescribed porosity onto heat-releasing surfaces is considered. Implementation of this method in experimental investigations of the boiling process on modified surfaces allows broad-range variations of the main parameters of microstructured capillary-porous coatings

A new method for image reconstruction from a series of digital holograms obtained by stepped phase shift with random values of phase shifts is under consideration. It is shown that images reconstructed from a digital hologram in a Fresnel region at a distance matching a distance from the object to the hologram consist of two parts, one of which is a clear image of the object and the other one being

Modern aviation industry solves the problem of developing multifunction engines capable of flying both at subsonic and supersonic speeds. An important part in such engines is a variable area nozzle, which allows varying the geometry of the engine exhaust unit and, accordingly, its technical characteristics. This study touches upon an computer vision based optical noncontact method for reconstructing

A method for forming p-n-diode based silicon electro-optic modulators using local oxidation is tested. It is shown that the local oxidation of silicon allows forming a rib waveguide as a smoothed trapezoid, in contrast to the classical technique of creating a rib waveguide by plasma-chemical etching. The main advantages of the approach used are described: controllability and reproducibility of critical

Two types of mirror structures with saturable absorption are under consideration: monolithic mirrors grown from semiconductor materials and mirrors with a dielectric reflector, with quantum well containing semiconductor structures transferred to the dielectric. Both types of mirrors manifest high reflectivity in the NIR range of the spectrum: the table width is about 100 nm for semiconductor reflectors

Diffusion of charge carriers in the photosensitive film of infrared mercury—cadmium—tellurium (MCT) focal plane arrays (FPAs) is simulated by the Monte Carlo method for determining the spatial resolution of these FPAs. Calculation results for matrix and linear FPAs with variously designed FPA pixels, including configurations with isolating diodes, are reported. The calculated data are compared with

The structure and photoluminescence of CH3NH3PbI3 (lead triiodide methylammonium) synthesized perovskite crystals are investigated in a wide temperature range. As temperature rises to 130–140 K, there is a junction from an orthorhombic to tetragonal crystal lattice with a change in the bandwidth. An increase in the stationary photoluminescence intensity at room temperature under the influence of exciting