In this paper, the previously obtained equation of motion in displacements is used to determine the frequencies and forms of free oscillations of the underground gas pipeline. The problem of solving this equation is reduced to finding the eigenvalues of the determinant, which are the squares of the natural frequencies of the cylindrical shell. Neglecting the secondary coefficients of the determinant and equating them to zero, the formula for the square of natural frequencies of an underground rectilinear thin-walled gas pipeline exposed to the action of internal working pressure and longitudinal force is obtained, taking into account the reaction of elastic resistance of the soil. Substituting the values for the wave numbers in the longitudinal and circumferential directions into the obtained formula, expressions for determining the frequencies according to the rod and shell theory are derived.Using these expressions, the dependence of the frequencies of free oscillations of the depth of the pipeline at fixed values of the pipe wall thickness, the coefficient of elastic resistance of the soil and the length parameter of the plot, for different values of internal pressure, the ratio of longitudinal compressive forces. When analyzing the results, it was found that with increasing depth of the pipeline, the frequency of free oscillations decreases, and at a certain depth, the frequency of free oscillations becomes equal to zero, this indicates a flattening of the cross section of the pipeline. Using the dynamic stability criterion, for which the frequency of free oscillations turns to zero, an expression is obtained that allows to determine the depth of the pipeline at which the stability loss of the second kind occurs.

Keywords: pipeline, frequency of free oscillations, depth of laying, coefficient of elastic resistance of soil, loss of stability

The article deals with the survey of transport and operational condition of the highway R224 " Samara-Orenburg in which it was found that the roadway surface is in poor condition due to the presence of transverse cracks, ruts and pits. In a survey of 5 existing culvert structures were identified unacceptable defects in the structure. Based on the foregoing, the specified section of road be repaired in accordance with GOST R 50597-2017 “roads and streets” . Currently, economical and mobile methods of inspection of road structures are of particular relevance. Conducting engineering surveys of the GPR system MIRA was determined the constructive layers of road clothes light. The decision on milling to a partial thickness of the pavement that runs recyclers WR 4200, with the subsequent device of asphaltgranulate type To

Keywords: pavement engineering, GPR applications, roads, surveys, MIRA GPR systempurposes of ensuring flexibility of production

In article the algorithm of calculation of systems with unilateral constraints with the replacement reactions of the supports on the force variables. The calculation algorithm is based on the finite element method in the form of the classical mixed method. The algorithm of search of version of the working constructive scheme is based on the modified "physically obvious" algorithm of design constructively nonlinear systems. The paper describes the features of the resolution system of the algorithm proposed by the authors and provides a flowchart. A comparative analysis with the algorithm of calculation of systems with unilateral constraints, proposed by the authors earlier, as well as some others. The efficiency of the algorithm is tested on numerical examples.The advantages of the proposed algorithm are: The vector of results includes the reaction of the support, which allows you to make a decision to change the design scheme; the calculation takes into account, as an additional loading factor, the size of the displasement in the realized one-way support, which increases the accuracy of the calculation.

Keywords: structural mechanics, single-sided supports, structural nonlinearity, the mixed form of the finite element method

The article discusses the current problems of calculating the distribution of water flow; the problems of current methods based on solving nonlinear equation systems are identified; proposes a new method for solving problems; analysis of the effectiveness of the proposed method; proposed a way to optimize the simulation calculations.

Keywords: waterways, water expenditures, modeling

We consider the problem of diagnosing breast cancer on the basis of combined thermometry. Diagnosis is carried out using two-dimensional generalized signs. Each such sign is formed on the basis of two one-dimensional. We propose an algorithm for the formation of sets of such features using tapering ellipses. On the basis of a set of such signs a classifier is built. By varying the semi-axes of the ellipses, the physician can control the sensitivity and specificity of the classifier. The doctor can fix the threshold value of specificity and achieve the maximum value of sensitivity. As a result of computational experiments, we built a family of 300 sets of two-dimensional signs and implemented a classifier customized by the doctor.

Keywords: combined thermometry, diagnostic algorithms, data analysis, algorithm sensitivity, algorithm specificity, logistic regression, custom classifier, breast screening, mammology

In this paper, we propose a method for expanding the functional range of image pre-processing systems (LUTs) and increasing sensitivity by reducing processing time. The main advantage of the implementation of preprocessing at FPSS is the implementation of spatio-temporal discrete-analog processing simultaneously with image formation. A disadvantage of the known methods for implementing image pre-processing systems is the low performance of the LDPE due to the fact that the processing is carried out step by step and the number of cycles is always the maximum regardless of the observation conditions. The purpose of the work is to expand the functional range of software and increase sensitivity, by reducing processing time. This goal was achieved by combining processing for the symmetric coefficients of the impulse response of a non-recursive filter. To assess the possibilities of improving the speed of the proposed processing method, noise suppression modeling on an X-ray image was simulated using low-pass filters with masks of size,,. Based on the difference between the original and processed images, it was concluded that the use of a mask is advisable. The use of a new processing method with a mask of dimension will allow to increase the performance by 2.778 times and, accordingly, the sensitivity of the software with 1.339 times.

Keywords: pre-processing, spatio-temporal, images, charge-coupled photosensitive devices, non-recursive filter

The technology of oil production includes a large number of processes in its cycle; extraction is one of the most energy-intensive processes before distillation of miscella. Analysis of automated extraction control methods determines the optimal process control method, which allows to improve the quality of miscella and save product consumption.

Keywords: automated, miscella, extraction, control, system, analysis, method, flow, solvent, quality

The generalized approach of statistical processing of results of fatigue tests of samples on the basis of a choice of numerical characteristics of parameter of static durability, processing of results of fatigue tests with use of methods of mathematical statistics, construction of a fatigue curve according to the linear regression analysis of mechanical characteristics of materials of designs and machines, definition of parameters of function of distribution of a limit of endurance by results of processing of diagrams of step change of loading is offered.

Keywords: Static strength, cyclic strength, reliability, mechanical properties of materials, endurance limit, mathematical statistics, linear regression analysis, method of step change of load, test planning

The article deals with mathematical modeling of thin-film materials production, based on the solution of multi-criteria optimization problems by convolution criteria. The method of estimation of coefficients in linear convolution is presented. The mathematical model developed by the authors allows to calculate the maximum profit of the enterprise from the production of thin-film materials, taking into account the cost of their production.

Keywords: thin film, substrate, production, mathematical modeling, multi-criteria optimization, convolution of criteria

Based on Dual-Phase-Lag theory a mathematical model of heat transfer in a rod was developed. During the derivation of the differential equation, the modified Fourier law was used. Analysis of the calculation results made it possible to determine the dependence of the optimal rod length on the intensity of heat transfer from its side surface.

Keywords: heat transfer intensification, third kind boundary conditions, temporal nonlocality, Dual-Phase-Lag theory, finite-difference method

A methodology for the study of associative memory devices and systems in the environment of functional-logical modeling MatLab / Simulink and the development tools of programmable logic integrated circuits is proposed. To this end, it is proposed to implement the typing of the representation and modeling of such devices and systems by implementing the characteristics of the representation and organization of network associative structures in the modeling environment.

Keywords: Associative memory devices and systems, functional and logical modeling

The article considers the solution of the problem of determining the dynamic characteristics of the relative humidity sensor, the mathematical model of which was based on the first order aperiodic link. The solution algorithm consists in minimizing the value of the standard mismatch of the approximating function and the set of experimental data. The results of processing experiments with the DHT-22 temperature and humidity sensor are presented. The sensor was placed three times in a medium with high humidity, which allowed to obtain an average experimental transient response. The period of measurement and registration of humidity and temperature was 1.5 seconds. The proposed method of calculating the dynamic parameters of the sensor allowed to determine the value of the time constant and the gain of the aperiodic link for the sensor under study. The obtained dynamic characteristics can be used to form an inverse transfer function for the humidity sensor.

Keywords: capacitive humidity sensor transient response, the sequence of measurements, the time constant, the minimization of the error

The possibility of reducing the excessive strength of self-compacting high-strength concrete for use in general construction was investigated. As a cement for such concrete, a cement-ash binder was studied, part of which was replaced by an inert mineral additive - microquatz, obtained by grinding quartz sand. It was established that the studied additive at a dosage of up to 30% does not allow to reduce the strength of concrete to the values ​​characteristic of general purpose concrete. It has been experimentally shown that the replacement of a part of the binder with microquartz does not significantly affect the initial modulus of elasticity, but significantly reduces the fast-flowing creep

Keywords: high-strength self-compacting concrete, cement-ash binder, inert mineral additive, microquartz, strength, modulus of elasticity, fast-flowing creep

In this paper, the concept of minimal intuitionistic dominating vertex subset of intuitionistic fuzzy graph was considered, and on its basis the notion of a domination set as an invariant of the intuitionistic fuzzy graph was considered. A method and an algorithm for finding all minimal intuitionistic dominating vertex subset and domination set were proposed. This method is the generalization of Maghout’s method for fuzzy graphs. The example of finding the domination set of the intuitionistic fuzzy graph was considered as well. The considered method and algorithm can be used to find other invariants, in particular, externally stable set, intuitionistic base and antibase of the intuitionistic fuzzy graphs.

Keywords: intuitionistic fuzzy set, degree of belonging, degree of non-belonging, fuzzy relation, intuitionistic fuzzy graph, intuitionistic fuzzy graph of the first kind, domination set, algorithm, disjunctive member, adjacency matrix

The introduction of RPP to 3% by weight of the dry concrete mixture is accompanied by a decrease in the compressive strength of fine-grained concrete aged from 28 days to 37%, and after 75 cycles of freezing and thawing - up to 46%. The decrease in tensile strength in bending at the age of 28 days was 25%, after 75 cycles - up to 23%. The dependence of the initial modulus of elasticity of concrete on the compressive strength remains virtually unchanged after 75 cycles of freezing and thawing. The dependence of the adhesion of MZB to the concrete base with increasing dosage of RPP is ambiguous. The maximum increase in adhesion to the concrete base after 28 days of curing in NU and after 75 cycles of freezing and thawing was 26%. An increase in RPP dosage to 3% leads to a decrease in the initial elastic modulus of MZB to 26% after 28 days of curing in NU and to 32% after 75 cycles of freezing and thawing.

Keywords: dry building mixes, redispersible polymer powders, adhesion to the base, elastic modulus, tensile strength, freezing and thawing cycles