The paper proposes a theoretical model of self-oscillators based on resonant tunneling diodes. Numerical modeling of the synchronization band of the oscillator was carried out on its basis. The effect of spreading resistance and resonator inductance on the synchronization band is analyzed. It is shown that at a low quality factor, as well as taking into account the nonlinearity of the capacitance and auto-bias, the frequency characteristics of the self-oscillator will be asymmetric and the instability regions of synchronous stationary oscillations will have a complex shape.

Keywords: theoretical model, numerical simulation, quality factor of an oscillatory system, synchronization bandwidth, capacitance nonlinearity, auto-bias, frequency characteristics, instability region, spreading resistance, resonator inductance

This article discusses a new method for adjusting the ground speed of a multicopter-type unmanned aerial vehicle and the initial, previously planned trajectory of its movement, taking into account horizontal stationary wind flows. The use of this technique for local rescheduling of the trajectories being worked out makes it possible to reduce the probability of loss of stability and controllability of such a device, as well as to reduce energy costs when driving in conditions of significant winds with an acceptable deviation from the initial trajectory. The developed algorithm is the basis for the synthesis of more accurate algorithms for local correction of the initial trajectory of motion in a complex field of wind speeds. The efficiency of the algorithm is confirmed by the physical correctness of the simulation results.

Keywords: unmanned aerial vehicle, wind load, stability and controllability of the vehicle, local adjustment of the planned trajectory, reduction of energy costs

The results of clinical trials are the main source of information in the implementation of medical activities in accordance with the principles of evidence-based medicine. At the moment, there are no information systems that would allow a doctor to select clinical studies within the framework of nosology that best match the profile of a particular patient, in order to further analyze their results and select therapy. The aim of the study was to improve the existing process of searching for clinical trials by using the prioritization method according to the inclusion criteria set by the doctor during the selection. To achieve this goal, the following tasks were implemented, namely, the process of selecting and searching for clinical trials by doctors was studied and the method of searching for clinical trials by doctors and the allocation of the necessary criteria was worked out. The team of authors proposed an algorithm for searching for clinical trials according to inclusion criteria, which in turn will significantly increase the effectiveness and reduce the time for searching and choosing therapy.

Keywords: clinical studies, criteria search algorithms, criteria search methods, including factors, search for the nearest class, services

Modern methods of determining the parameters of the tool do not take into account all the features of deep loosening, first of all, such important indicators of the quality of soil decompression as the degree of crumbling and the configuration of the loosening zone. Therefore, the search for a solution to the problem of assessing the quality of soil decompression at the design stage, depending on the parameters of the working bodies of the deep miner and the specified physical and mechanical characteristics of the soil is an urgent task. The aim of the work is to develop an algorithm for assessing the influence of the parameters of the upper reformers on the quality of crumbling and the loosening zone based on modern mathematical and simulation modeling technologies. This is achieved by developing a method for determining the parameters of the loosening elements of the deep miner on the basis of modeling the processes of interaction of loosening elements with the soil, taking into account factors that determine the quality of decompression and the energy intensity of the decompression process of the cultivated soil.

Keywords: mathematical modeling, deep loosening, soil loosening elements, calculation algorithm, degree of crumbling

Global Positioning System (GPS) data acquisition devices have proven to be useful tools for collecting real-world motion data. The data collected by these devices provide valuable information when studying the vehicle movement parameters. For vehicle modeling, this data is invaluable for analyzing fuel consumption and vehicle performance. The study presents a methodology for developing the driving cycle of special cars, during which the speed profile of a particular type of vehicle is studied, loaded and processed, and noisy data is filtered for the purity of the experiment. The test data for severe operating conditions are analyzed. A city driving cycle has been developed for a special truck concrete mixer truck in the conditions of the city of Tyumen. Estimated fuel economy of the specified vehicle is estimated.

Keywords: driving cycle, fuel efficiency of concrete mixer truck, noisy data, data filtering, GLONASS/GPS

The article considers the possibility of replacing a monolithic frame with a precast-monolithic frame during the construction of a residential apartment building. The variety of structural systems erected in the Russian Federation for residential and public buildings is given. The positive and negative aspects of each of the proposed methods are considered. An economic justification for replacing a monolithic frame with a precast-monolithic one is given. Based on the results obtained, conclusions were drawn about the effectiveness of the use of prefabricated monolithic systems for the construction of civil buildings.

Keywords: construction, construction technology, monolithic frame, prefabricated monolithic frame, prefabricated structures, construction period, construction cost

This work is devoted to modeling the absorption of microwave electromagnetic field energy in a device for milk pasteurization. Using CAD FEKO, a 3D model of the device was built and its operation was simulated. A study was made of the influence of the tilt angle of quartz tubes on the distribution of the electromagnetic field in the waveguide. The influence of the diameter and material of the tubes is also considered. The distributions of the electric field and the specific power absorbed per kg of dielectric in the waveguide are obtained. The accuracy of the results was assessed.

Keywords: pasteurization, microwave, heat treatment of dielectrics

The unique building of the Center for Science and Art is modeled as a variant of the complex development of the territory of the old hippodrome in Rostov-on-Don. The analysis of the formation of vertical external communication parametric structures for a spherical object is performed. Based on the results of the consideration of ten forms, a rational form of "Turban" was determined, which retains a constant comfortable slope, and in emergency situations can go into autonomous mode while maintaining the rigidity of the structure. Visualization of the object's integration into the urban environment was carried out in Rhino 3D using the Grasshopper visual programming language program. By combining specialized years, modeling of roads and the volumetric geometry of buildings, the object of study, zoning and reading information from the surrounding area was carried out. The resulting model allows us to evaluate the aesthetics and comfort of the urban environment in the case of construction of a new facility.

Keywords: unique buildings, modeling, parametric architecture, urban environment, grasshopper

The article describes a method for translating pictogram messages into text in Russian language based on machine learning. The text of the article contains the concept of alternative communication systems, a description of the training data preparing process, a description of the neural network architecture and the results of training.

Keywords: alternative communication systems, machine translation, machine learning, neural network, transformer architecture, Python, software

The question of creating an automated accompaniment is still an undisclosed part within the current automation of the musical field. The construction of accompaniment is used not only in the musical field, but also in related ones. Automatically generated accompaniment is used in audio and video studios for advertising, by people with and without musical education. In this paper, the existing methods for constructing automated accompaniment, audio file formats will be considered, and the developed algorithm and method for automatic accompaniment generation will be described.

Keywords: accompaniment, auto generated accompaniment, auto accompaniment, melody, MIDI

The article presents an approach to the development of a case-based decision support system for assessing the safety of a section of a city's transport system. To store the database of precedents, it is proposed to use an OWL ontology. The use of the ontological approach allows a more accurate interpretation of the subject area, and over time will expand and supplement information about the precedent. The precedent structure is defined. The ontology architecture is given: classes, properties and instances. An example of filling the ontology with precedents is given, using the example of the city of Volgograd. Measure of proximity to compare precedents is proposed. The procedure for adding new precedents to the knowledge base is considered. With the help of the developed decision support system, it is possible to assess the safety of both individual road sections and the entire transport infrastructure of the city.

Keywords: ontology, reasoning by precedents, transport, transport security

The work is devoted to the analysis of the frequency characteristics of a piecewise homogeneous coaxial Bragg microwave structure with irregularities in the inner conductor. The article presents varieties of piecewise-homogeneous Bragg coaxial microwave structures, their options for practical application and implementation, as well as the possibility of their modernization, and also considers a recurrent method for calculating a piecewise-homogeneous transmission line. The possibility of using lumped capacitances in an equivalent circuit is considered and simulation is carried out in the electrodynamic simulation program with initial parameters.Based on the results of the work done, it was concluded that the effect of lumped capacitances included in the equivalent circuit of a piecewise homogeneous coaxial Bragg microwave structure significantly improves the frequency characteristics of a single-wave calculation in comparison with full-wave simulation. When approaching conditions favorable for the propagation of the first highest mode, it is necessary to include the effects of its propagation in the calculation.

Keywords: Bragg microwave structure, reactivity, permittivity, coaxial cable, microwave range

The construction of a Polar gas turbine power plant is carried out on permafrost soils. Features of the construction of reinforced concrete structures of foundations and other elements in the permafrost zone implies high requirements for strength, density and frost resistance. A new composition of the concrete mixture with improved physical and mechanical properties is proposed. Superplasticizing additives and production waste are used in the composition of the concrete mixture.

Keywords: foundation, permafrost, borehole piles, superplasticizer, sulfuric acid sludge, concrete mix, strength, frost resistance

The article proposes new compositions of a fast-hardening concrete mixture using Portland cement, fine and coarse aggregates, basalt fiber, a complex modifying additive including acetone-formaldehyde resins and magnesium chloride (bischofite). The results of scientific and experimental studies are presented and the influence of the proposed additives on the formation of the structure, rheological and physico-mechanical properties of fast-hardening concrete is determined. Analysis of the test results showed that the proposed formulations, including a complex additive and basalt fiber, contributed to a decrease in the water-cement ratio, increased mobility of the mixture and increased strength of hardened concrete in the early and final hardening periods.

Keywords: concretes, oil and gas storage, modifying additives, fiber, mobility, setting time, strength

The task of planning the trajectory of a mobile robot is considered in the following formulation: it is necessary to choose the optimal trajectory of the robot's movement over hilly terrain from one point to another among the many available paths. The developed algorithm for planning the optimal trajectory of movement of mobile objects allows minimizing energy costs when moving over hilly terrain. The optimal trajectory is determined from the condition of minimum of the functional of the rolling friction forces work. To find the optimal trajectory on which the friction forces work is minimal, is used the dynamic programming method. The proposed algorithm for planning the optimal trajectory can be used to reduce energy consumption in the process of moving over hilly terrain not only autonomous robotic systems, but also other vehicles.

Keywords: planning algorithms, rolling friction force operation, dynamic programming, optimization according to the selected criterion