This article discusses the economic approach to the choice of the mode of continuation of the system in the face of partial failure. It discusses strategies related to the continuation of work in conditions of partial failure or cessation of operation until the completion of the operational restoration process. The characteristics of each of the strategies are presented in a comparative aspect for the continuation of the operation of the object in the post-failure period or the delay in operation for the duration of the restoration. The dependence of the time recovery parameters and the times defining the moment of identifying a partial failure in the coordinates of the time axis from the beginning of the working cycle to the next scheduled maintenance has been revealed. The resulting mathematical expressions allow, under certain conditions, to justify the choice of one of the two strategies considered. For more complex cases, it is proposed to use expert approaches to take into account additional characteristics of the process, such interregional period, performance and acceptable risks associated with working in conditions of partial failure. The article provides graphs illustrating the change in reliability characteristics in two ways of developments of events related to the adoption of a decision to continue work.

Keywords: partial failure, the coefficient of gain in terms of work, the probability of uptime, recovery time, time in the post failure period

The dependence of influence of size of a bend on tensely strained state of load-bearing frames of a covering is analysed. On the basis of the received results the maximum corner of a bend of the metal corners reducing a carrying capacity of farms is defined.

Keywords: a rafter farm, bend, tensely strained state, a moment of inertia, a radius of gyration, a barycentre

The article deals with the work of mechanical absorbers, where the working body is presented in the form of a rotating cylinder. The analysis of interaction of liquids and a working body in similar devices is made. The mutual influence of liquid layers and the action of the working body are considered. The estimation of the force factors of the dynamic layer entrained by the rotating cylinder is obtained. The study presented in the article will help in the preparation of engineering methods for calculating the operating and design parameters of devices.

Keywords: absorber, emulsion layer, capillary forces, emulsion, static meniscus region, capillary pressure, immiscible liquids, rotating cylinder, liquid, Navier-Stokes equation

The development of modern technology makes increasingly stringent requirements for materials, and improving the reliability and durability is an urgent task for many industries. One of the most important elements of the automatic coupling device of the car is the absorbing device. The parts included in it must meet high standards, be reliable and provide the necessary hardness and mechanical properties of the materials throughout the life cycle of the car. One of these parts included in the friction unit of the absorbing device is a movable plate. In the present work, an example of modernization of the absorbing apparatus through the use of modern methods of modeling and manufacturing of a fixed plate is given. The technical result is to reduce consumption of materials of the movable plate, and to simplify the manufacturing process of the plate by making it from rolled steel.

Keywords: Absorbing apparatus, modeling, mobile plate, energy consumption, friction unit, friction, wear resistance, reliability, durability

The article provides a solution to the problem of the stress-strain state of the base in the field of karst dip. The problem is considered in the linear formulation for a layer of bounded thickness weakened by a cylindrical notch. The solution is obtained in polynomials based on the use of the Solyanik – Crass stress functions satisfying a quasi-harmonic type differential equation. The main task was solved on the basis of using the principle of superposition. The verification of the obtained solution was carried out on the basis of a comparison of the components of the stress and displacement tensor with the results of numerical solutions. Graphs constructed using the Mathcad mathematical complex and the Plaxis software complex were considered. Their analysis showed good convergence of the results.

Keywords: Karst, cylindrical cavity, stresses, displacements, isopolis, linear formulation, mixed problem

The main goal of modernization in the field of education in the world is to achieve a new quality of the educational process corresponding to the new socio-economic conditions. This requires effective organization of the educational process, which will facilitate the search and development of abilities in each student. The result of the teacher’s work should be an active, creative, and cognitive organization of students' joint activities. Also important is the development of students' skills of the 21st century, which would be useful in their future professional activity, where the latter requires the ability to work not only with information, but also with people. These can be communication skills and teamwork skills, flexibility and adaptability, the use of the aggregate intelligence of a group that is a joint activity to achieve the goals.

Keywords: Internet, Web 2.0 tools, social network, cognitive activity, network services

This article discusses the main problems faced by experts in the construction and technical expertise of real estate. The measures that can improve the quality in the performance of judicial construction and technical expertise are considered.

Keywords: optimization, judicial construction and technical expertise, litigation, major problems, construction contract, construction and installation work, completed

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

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

This article discusses various configurations of dielectric inhomogeneous waveguides in the microwave range, discusses the results of computer electrodynamic modeling of the proposed configurations of structures with periodic inhomogeneities. During the simulation, the geometric and electrophysical parameters of the periodic structure were varied in order to identify their influence on the characteristics of the proposed sensor to determine the properties of liquid dielectric media.

Keywords: dielectric waveguide, Bragg reflection, dielectric constant, reflection coefficient

The article focuses on radiowave propagation in complex conditions combining rough terrain with woodland or urban areas. The estimation of influence of all these factors on signal attenuation may be challenging. Consequently there are no propagation models for such environment for distances up to several kilometers. However by approximating the experimental data on radio wave attenuation it is possible to develop empirical propagation models for specific cases. The authors carried out a series of experiments to measure the level of radio signal at a given distance from the source. Based on the experimental results a hybrid model for rough terrain, wooded and urban areas for ground communications systems was developed.

Keywords: radiowave propagation, UHF, experimental study, rough terrain, urban area, wooded area, empirical model, radiowave attenuation, path loss, ground mobile communication

The statistical characteristics and results of the FIPS 140-2 tests of a new class of pseudo-random signal generators based on modified Lorentz, Chua and Dmitriev-Kislov systems over the finite Galois field are considered. The estimates of the sidelobe levels of the correlation functions of the signals, as well as histograms of the probability distributions of the generated numbers, are obtained. Evaluations of compliance with the requirements of the FIPS 140-2 test of binary sequences generated on the basis of systems under variation of their parameters are obtained. The results of the work can be used in the construction of communication systems with broadband signals, simulation and cryptography.

Keywords: dynamic chaos, radioelectronic dynamic systems, statistical properties

A theoretical calculation of the transmission coefficient of the microwave converter on a resonant tunneling diode, where the same diode is used as a mixer and amplifier of microwave oscillations, is carried out. In this case, as shown by calculations, the transmission coefficient increases due to the use of regeneration, and also because the non-linearity of the current-voltage characteristic of a resonant tunneling diode is much larger than that of conventional microwave diodes with a Schottky barrier.

Keywords: transfer coefficient, regeneration, resonant tunnel diode (RTD), volt-ampere characteristic (VAC), input amplifier, equivalent mixer, intermediate frequency transfer coefficient, input amplifier transfer coefficient, dual-barrier heterostructure

The article contains information about the formats, types, advantages of banner advertising, made analysis of errors that allow developers and customers, developed a General principle of successful visualization of banner advertising for the tourism sector.

Keywords: banner advertising, banner, tourism, offer, Internet, advertising, efficiency, layout, layout, rule of thirds