Economic-probabilistic method assesses the feasibility of tactics for MAINTENANCE and operating time and technical condition for buses equipped with electronic control units. The scheme of determination of limit values of diagnostic parameters is proved. It is shown that the implementation of the STATE is appropriate when the economic costs associated with the cost of diagnosing and forecasting the technical condition of the buses are not decisive.

Keywords: strategy, tactics, method, parameter, maintenance, repair, cost, reliability, operation, technical condition

On the basis of the mathematical apparatus of Queuing, a mathematical model for the diagnosis of the technical condition of vehicles with electronic control units. The developed mathematical model of vehicle diagnostics in the framework of discrete-event paradigm. Numerical experiments to assess the effectiveness of diagnostics are carried out.

Keywords: cars, electronic control unit, diagnostics, Queuing system, efficiency, operating costs

The article is devoted to the actual problem of overcoming the restrictions imposed by the IP Protocol and network technologies used in conjunction with it, in particular, address translation, on the structure of computer networks and the availability of its individual nodes. It proposes a method of building virtual network tunnels based on the principles of steganography using service network protocols, briefly describes the shortcomings of existing technologies of tunneling. The paper describes in detail the proposed method of steganographic encapsulation of network packets, describes the principles of formation of packet headers, provides examples of protocols for encapsulation. The material of the article is presented consistently, competently and meets the generally accepted requirements for scientific works. The presented approach to solving the problem of building virtual tunnels has scientific novelty and has practical value.

Keywords: Encapsulation, Internet protocols, multilevel network models, steganography, steganographic packet encapsulation, tunneling

The method of layer-by-layer build-up of the material allows creating parts of complex configuration.To expand the field of application of such parts in the industry, it is necessary to know the properties of products obtained by this wayvery well. Currently, the literature sources do not provide enough information about the properties of products obtained by 3D printing on FDM-technologies.This is due to the variety of materials used and printing modes.Data on mechanical properties, such as tensile strength, bending, compression, shrinkage, specific weight of the material, will allow designing and creating real structures using 3D printing.The article considers the extrusion method of 3D printing, describes the study of tension, compression, bending, specific weight, shrinkage of samples with different structures obtained from ABS plastic.It is found that the deformation of the material during its tension depends on the number of filaments on the shell of the surface layer and reaches the highest values for samples containing eight and ten filaments. The calculation of the specific weight of the samples shows that the density of the samples with a tetrahedral structure is higher compared to the hexahedral structure at the same printing and filling modes. In determining the ultimate compressive strength of the samples, it is revealed: the higher the percentage of sample filling material, the more the sample withstands compressive stress. Experimental data on material shrinkage show that when filling the model with material from 20 to 80% shrinkage is 1%, and at 100% filling - 0.78%.

Keywords: additive manufacturing, 3D extrusion printing, mechanical property, FDM technologies, ABS plastic

Executed system analysis of the types of damage to logging machines and damage them in the manufacture. It is found that defects in material, shape and size of the part have a significant impact on the reliability of the equipment. The main attention is paid to the effect of crack-like defects. If as a measure of damage to take the length of the crack and apply the methods of fracture mechanics in the calculations, it will be obvious the relationship of operational and industrial damage. It is established that the main cause of failures of logging machine details of domestic production is not enough high quality of their production. It is recommended to use more widely such as characteristic of materials as fracture toughness to assess the reliability of the design.

Keywords: Logging machine, reliability, damage, manufacturing defects, fracture toughness

There are represented scheme and design of duplexer for the 300-344 MHz radio station. Simulation of duplexer was implemented in Microwave Office environment. Experimental research was executed on the complex transmission coefficient measuring instrument such as “Obzor-103”. There are shown amplitude-frecuency characteristic of receive and transmission channels. Comparison of the simulations results with natural experiment proving the identical.

Keywords: Filter, duplexer, amplitude-frequency characteristics, receive channel, transmission channel

The analysis of the used algorithms for the search of unstructured information was carried out, during which it was established that they do not take into account the thematic orientation of the specialized collection of documents. It is proposed to use an annealing simulation algorithm to obtain numerical coefficients used in the information retrieval ranking algorithm system. The results of the standard and modified search algorithm and ranking search results unstructured information. As a result, the value of quality metrics failed improve by an average of 8%, and the average error decreased by 29%

Keywords: information retrieval, ranking, model, quality metrics, relevance, unstructured information

Offers on the rational organization of control of durability of concrete according to GOST 18105 for modular products, commodity concrete mix and monolithic designs are presented. The concept of "moving analyzed period"is introduced. It is shown that it is not reasonable to use the control scheme for the control of the indirect indicators and the development of rapid methods for assessing the strength of concrete in the control of commercial concrete mixtures. The rational organization of concrete strength control of monolithic structures using direct and indirect methods is proposed. The groundlessness of application of statistical methods of control at control of durability of concrete of monolithic designs is shown.

Keywords: control of the concrete strength, the analyzed period, the control scheme, the actual concrete strength

A study of the directional coupler range 1-4GHz. The description of the construction on a symmetrical strip line with a lateral connection is given. The amplitude-frequency characteristics were simulated using the Microwave Office package. The model of the directional coupler is experimentally investigated, the following results are obtained: the working attenuation does not exceed 1.7 dB, the transient attenuation does not exceed 10 dB.

Keywords: Directional coupler, frequency response, flatness, symmetric stripline

" The analysis of the influence of superplasticizers based on polycarboxylates on the formation of physical and mechanical properties of concrete under thermal influence. It is established that the high efficiency of the steamed self-compacting concrete with polycarboxylate-based superplasticizers is achieved at low-temperature modes of heat treatment. Rational mode of heat treatment of concrete should be assigned to the quality parameter established by the results of experimental studies. Article is published within implementation of the program of the International Forum «Victorious May, 1945»."

Keywords: construction materials producing industry, unburnt synthanite, apparatus with vortex layer, innovation, commercial soundness of investments, investment prospects, method of variation of parameters, uncertainty

This article analyzes the possibility of decomposing a radio engineering system into parts, provided that one of the two stabilizing parameters of the coupling scheme is adjusted. An analytical calculation was made (in general), which proves the possibility of adjusting only one stabilizing parameter in the coupling scheme. A numerical example is provided confirming the above idea.

Keywords: HIL simulation, radio engineering system, decomposition, coupling scheme, stabilizing parameter, coupling two-port network, ideal time delay line, Schur complement, Y-parameters

The task of creating a file format containing an image having an optimized (compressed) size is considered. The source file is in BMP format. The problem is solved on the basis of optimal interpolation of the data by polynomials of various degrees. The simulation of the algorithmization process was performed in the MATLAB package. The proposed algorithm showed good compression of the initial information.

Keywords: image, BMP format, compression, algorithm, polynomial regression

The article deals with the problem of pedestrian crossings and congestion of highways of the city of Volgograd. It described the situation on the highways and solutions to eliminate congestion on the road. Car traffic was conditionally divided into 3 categories: transit, the transit from the center and the car flow moving into the center. Studied the question of the safety of pedestrians on the road, because, except for pedestrians with the intersection increases their safety. The study and analysis of all previously implemented measures was proposed construction of underground pedestrian tunnels. Several embodiments of tunnel junctions have been considered. Analysis of the current transport situation revealed the busiest places in the city center.It was noted that the construction of underpasses solve the problem of vehicular traffic in the city center and pedestrian safety, and the city will have new underground space.

Keywords: Сar flow,highway, tunnel transition, transit transport, carriageway, longitudinal,security,road traffic

Physical and chemical properties of cobalt catalysts for Fischer-Tropsch synthesis are investigated. The influence of copper and zirconium oxides on the specific surface area, cobalt concentration, pore volume and size, the degree of reduction of the catalyst Co-Al2O3/SiO2 was studied.

Keywords: Fischer-Tropsch synthesis, carbonaceous resources, catalyst, active component, silicate carrier, CuO and ZrO2 promoters, elemental analysis, recovery rate, BET method, specific surface area

The study of physical and chemical properties of cobalt catalysts in the synthesis of hydrocarbons by the Fischer-Tropsch method is carried out. The effect of additives promoters NiO, Fe2O3, MnO2, on the specific surface area, pore volume, size of cobalt crystallites, the degree of catalyst reduction is considered

Keywords: Fischer-Tropsch synthesis, synthetic hydrocarbons, catalyst, promoter, carrier, specific surface area, porous structure, catalytic activity, dispersion, cobalt crystallites