The article describes a method for processing of video recordings of flame front propagation in narrow channels using a computer vision library based on the open source code OpenCV. Using the results of machine processing, new data on flame sustainability and topology in a two-dimensional Hele-Shaw channel were obtained. The dependence of apparent speed on the channel gap width demonstrates that the wider the gap, the faster flame propagation growth due to reduced influence of viscosity and heat loss.

The study analyzes multichannel digital satellite navigation signal processing systems for unmanned aerial vehicles. To advance interference insusceptibility of navigation equipment on the basis of adaptive change in settings, it is advisable to apply a field programmable gate arrays in order to implement variations of algorithms of signal processing without reconfiguring the equipment’s structure in changes in radioelectronic settings.
A navigation complex with the function of interference insusceptibility is developed based on the field programmable gate arrays. It may simultaneously receive signals from such satellite navigation systems as GLONASS, GPS, QZSS, BeiDou, Galileo, and NavIC via four independently tuned channels and their digital processing using adaptive filtering algorithms. Patterns in spatial selectivity of signals are studied, as are the possibilities for navigation equipment adaptability in interference settings using programs for electrodynamic modeling of adaptive antenna arrays ‒ SolidWorks, Altium Designer, and Quartus.

The article considers the problems of modeling a table with a set of competing parties and a group pursuit of multiple targets. Each table cell represents a structural variable containing data about the predicted time required for an ith pursuer to reach a jth target. For each finite set of pursuer’s distribution by targets, the minimum time value of the pursuer’s reaching the target is selected out of all permissible max-imum ones. Upon analyzing the problems based on the models of real-world objects movements, the author suggests using them for simulation modeling, virtual modeling of game processes, and transport logistics, as well as for developing virtual reality models for parcel delivery performed by drones using a hub-network.

The article presents the objectives and developmental stages of an information monitoring system for regional drafts and the system’s testing through implementation of a draft for self-determination and career guidance of students in the Khanty-Mansi Autonomous Okrug ‒ Ugra (https://monitoring.sur-gut.digital). This includes a concept analysis of the subject field, development of software architecture, design of a user interface elements, algorithms programming, and objectives to broaden the system’s functions and prospects for its scaling in order to expand its geographical use.

The article presents engineering solutions for creating a wireless system for data sampling of cathode protection for gas transmission pipelines. These aim at advancing level of automated monitoring of parameters of corrosion protection using existing methods and regulations on pipelines maintenance in force.

The article presents the stages of developing and building a mathematical model for a semi-conductor frequency converter with space vector pulse width modulation, which consists of a power circuit made of power semiconductor elements. The mathematical simulation is performed in the MATLAB/Simulink soft-ware environment. The main principles of the model’s components performance are formulated. Using switching diagrams, calculated data for building a functional management system for the power keys of a frequency converter are presented. Based on the simulation results, oscillography records of phase and linear load voltages are obtained. Dependences of output voltage quality on the frequency of pulse width modulation are identified. The main advantages of using space vector pulse width modulation are described in designing sinusoids of output voltage in a frequency converter when working with an active inductive load. The authors draw conclusions on the usage of the vector method for building an output voltage of a frequency converter in the industry.

The article presents a numerical study of the gas hydrate dissociation model in a reservoir under the action of microwave electromagnetic radiation at 400 MHz, 1 000 MHz, and 2 450 MHz. The decomposition of gas hydrate under this influence is faster at lower values of the reservoir’s initial hydrate saturation. The effects of 1 000 MHz and 2 450 MHz frequencies are much stronger than those of 400 MHz. The study shows that during heating times higher than 400 hours, 1 000 MHz frequency radiation electromagnetic heating is more efficient than that of 2 450 MHz frequency. Using the proposed mathematical model, it is possible to determine the optimal frequencies of the radiation source at a given time of heating the reservoir of a particular field. Moreover, the resulting calculation of energy efficiency (EROI ≥ 10) of this method for gas hydrate-extracted gas proves its competitiveness when compared to traditional methods of thermal impact on the reservoir.

The study presents an analysis of well testing using the pressure draw-down curve method after hydraulic fracturing in 2018‒2019. According to the analysis, that 67 % of studies are not data-supported, whereas 33 % are credible. Some study parameters were not employed due to the reasons described in the article. A scrutinized analysis of possible deviations in the results of the studies from the design concept for hydraulic fracturing is conducted. It is noted that fracture half-length and formation pressure determined by well testing differ from those determined by planning. Based on the results of the pressure draw-down curve, the author determines the dependence of the time required for the diagnosis of radial filtration mode on the range of reservoir permeability and the value of the half-length of a fracture. Based on the Nolte‒Smith plot, an approach to determining the nature of fracture development is proposed in order to obtain parameters sig-nificant for planning, control, and analysis of field development and geological and engineering activities and are used for detecting well deliverability and inflow area created due to hydraulic fracturing.

The article presents a frame of a systematic approach to assessment, control, and formation of dynamic states based on the concept of level ties of elements of technical objects subjected to connected vibrational loadings. The methodological basis of the study comprises structural mathematical modeling that allows for a comparison of mechanical oscillatory systems, which are used as computational models for tech-nical objects, with structural schemes of automated operating systems that are equivalent to dynamic relations. A level interpretation of total generalized dynamic states is designed for mechanical oscillatory systems created with solid body with three degrees of freedom. Their significant features are reflected in the number of reso-nances, modes of oscillation amplitude setting to zero, and definite form of dynamic interactions. Based on the level ties, a system of general concepts is developed to depict the role of connection of vibrational loadings in creating border dynamic states of mechanical oscillatory systems. The results consist of analytical equations, graphical images, and numerical experiments.

The article describes an algorithm for a directed search to find the minimum disjunctive normal form using the lexicographic order.

The article proposes a method for calculating air resistance of a dense layer of natural solid fuel in order to forecast the drying installation size while taking into account the moisture phase change from liquid to steam and duration of drying process of various height layers with boiler unit’s exhaust gases. An algorithm is presented and temperature patterns of material and gas in ventilated moving dense coal layer is calculated considering air resistance of a dense layer when velocity of gas passing through the layers changes.