A comparative analysis of existing solutions to estimating the maximum packet transmission time in networks with end-to-end routing and time multiplexing is carried out. A method for estimating the maximum packet transmission time is proposed, with the account for the features of the considered avionics networks including schedule tables and the maximum waiting time for the release of channel resources. Presented results of a series of computational exper-iments demonstrate the adequacy and efficiency of the proposed method.

Several issues of positioning of mirror elements of segmented primary telescope mirror are theoretically investigated. Criteria for the quality of segmented mirror depending on its surface shape are considered. An algorithm for mirror surface adaptation (positioning of composite mirror segments) is presented. The proposed control system for composite mirror makes it possible to control the spatial position of the mirror segments and position them.

Phase masks made of birefringent CaCO3 crystal plates are developed to create laser beam with a given shape and intensity distribution close to flat-top in image construction scheme. The principle of phase masks operation is based on creating the phase shift of  or 2 (depending on the initial plate thickness) in linearly polarized radiation passing through etched areas with given shapes. The phase shift in these areas transforms into the intensity distribution at an analyzer output, which can be projected with a demagnification by a high-quality lens into its image plane aligned with the micro-processing plane (target). Phase masks in the form of a square and a square in a square are made by processing optically transparent materials with laser-induced microplasma and successfully tested in an experimental setup in an imaging scheme with a laser emitting pulses of 120 ns duration at the wavelength of 1.06 μm. Phase masks are also used in this experimental setup for laser ablation of polished steel samples. The shapes of footprints on samples well match the formed beams shapes.

The prospects and relevance of the optical spectroscopy method for study of modern stomatological restoration material are shown. A brief description of test sample is given. Technical characteristics of the automated spectral device UV-1280 are listed. Spectral dependences of optical transmittance of Omnichroma Blocker composite material are obtained. Transmission spectra are measured for ten samples with a thickness of 0.3; 0.5; 0.9 and more than 1 mm. It was determined that a layer thickness of 0.3–0.5 mm of this composite is sufficient to mask discolorations and make restorations opaque when restoring through cavities in the anterior teeth. It is shown that for a sample layer thickness of 0.3 mm, the transmission coefficient in the visible wavelength range does not exceed 10 %.

Results of modeling the process of the "M-sequence" type signal reflection from a single-layer coating with variable parameters are presented. The developed model makes it possible to obtain a signal at the output of the radar correlator without excluding the propagation medium. Modeling the process of reflection of pseudo-random signal from a single-layer coating with variable parameters demonstrates the fundamental possibility of creating false reflection points for radar without using active means of signal re-emission.

An optimized design of a disk antenna is described, which provides a circular (or sector) view as part of video surveillance sensors (azimuthal movement of objects, security systems, etc.). Theoretically calculated and experimentally measured radiation patterns of the emitters determined by their design features, are presented. The results allow to optimize gradually design of the all-round looking antenna, which is a system of two identical discs with four axial emitters on each disc extending radially from the discs centers. The angle between adjacent radiators on the disk is 90 °. The disks are located coaxially, while they have an azimuthal offset relative to each other at an angle of 45 °, which provides a full circular or any sector view in the azimuthal plane. For this antenna design, frequency separation of the radiators is also possible. Experimentally determined optimal distance between the disks providing the best (minimum) overlap of the main beams of the radiation patterns of the radiators and their electrodynamic decoupling, equals to the radiation wavelength λ for the central frequency f0 = 10 GHz (λ = 3 cm). The operating frequency range of the antenna is 8-12 GHz.

The current problems and limitations associated with improving the accuracy parameters, resolution, reliability indica-tors, as well as reducing the mass and size characteristics of photoelectric digital angle converters in products with a high degree of reliability, are analyzed. The degree of influence and causal relationships of factors preventing the im-provement of the main parameters of the rotation angle sensors are systematized, and a conclusion on possible direc-tions of reducing their impact to improve the characteristics of the converters is given.

A structural model of processes interrelation in biological wastewater treatment is proposed. The model accounts for the mutual influence of physical and biochemical processes and provides an analysis of the performance of anaerobic biological treatment systems during operation. It has been proven that continuous monitoring of the technical condition of these systems is necessary, focused primarily on identifying the causes of degradation of microorganisms. Based on a general approach to diagnostics of complex technical systems, algorithms for continuous monitoring of the technical condition of an anaerobic biological wastewater treatment system are proposed, which make it possible to identify the causes of malfunctions of various nature and reduce the number of laboratory tests carried out.