For a numerical study of the stress-strain state of the edge sections of a coal vein under the influence of a mining zone, there is a mathematical model of the geomass deformation processes, which is reproduced in the form of boundary value problems of the theory of elasticity. The problem was solved by the finite element method in a variational formulation, in which the functional was minimized with full potential energy to determine displacements in narrow of elements. Computational experiments were carried out using the author's complex of programs. Based on the results of numerical modeling, recommendations for strengthening the coal target and definitely bearing capacity was developed. The use of the developed mathematical model and software package allows us to design documents at the development stage, to predict the stress-strain state of the geomass in the zone of influence of the underground mining system.
Keywords: Mathematical model, numerical modeling, computational experiment, software package
The article provides information on the use of the geoinformation database of commercial real estate in the city of Rostov-on-Don. The database is designed to store information about commercial real estate with the aim of effectively managing the technical condition of the facilities. The prerequisites for creating a geographic information database was the need to manage the technical condition of commercial real estate of large companies on the basis of an outsourced agreement. The reference-geographic information system of commercial objects can be used for effective management, data processing and optimization of applications.
Keywords: geographic information systems; commercial real estate; technical exploitation; energy efficiency
This article is the result of a study of project documentation, one of the largest oil companies in the Russian Federation. This article aims to identify and identify systematic errors and deficiencies in the design of oil fields, which can lead to significant risks of accidents, damage to equipment, violation of the integrity of buildings, the emergence of threats to human life. The aim of the author was to identify and systematize these shortcomings, to offer the best options for correction for the purpose of further application, qualitative improvement and acceleration of the design of oil fields. Further examples of errors and shortcomings of project documentation, expected consequences which can occur if not to eliminate these errors and all necessary normative base on these questions will be given. Errors at the design stage, in turn, can lead to disastrous consequences, ranging from increased construction time, ending with emergencies and irreparable damage to the environment and human health, which leads to enormous economic losses. Design errors, even the most insignificant, can be compared with the butterfly effect. A minor mistake in the project can lead to grandiose consequences. Ballasting of pipelines. Ballasting of pipelines is taken into account in the installation of pipelines through water obstacles or water-bearing sections, when laying in the swamp.Depth of laying of pipelines at crossing of water barriers. The development of design solutions in the field of transitions on the materials of surveys that were carried out more than two years ago, without the implementation of actual engineering surveys is not allowed.Electrochemical protection of pipelines. At all available ways of laying, (except above-ground), irrespective of degree of aggressiveness of soil, pipelines shall be protected by complex anticorrosive substances and means of electrochemical protection are applied.The location of the purge of candles on the pipelines. The distance from a certain point to the purge plug in the construction of main pipelines from overhead wires must be taken from 300 meters, under cramped conditions of the route of high-voltage overhead lines, this distance can be reduced to 150 meters.the aim of the study was to identify design errors and their consequences, with the aim of further prevention and accounting. The result of these adjustments and corrections will be both cost savings and reduced construction time
Keywords: design, defects, field, capital construction, operation, analysis, research, documentation, expertise, violation
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
Within the plane-stress state the problem of a high-speed rotating disk being under side pressure is considered. Within the model of a perfect rigid-plastic body and the Mises yield criterion the allowable boundaries of external parameters have been defined. Within the model of a perfect elasto-plastic solid and the Mises yield criterion the limit state of the disk has been considered. The displacements and the deformations are assumed to be negligible quantity; deformation plasticity theory is chosen. The problem of defining the stresses is ecstatically determined. The displacements are determined together with the stresses. In order to define the displacements as single-valued within the model of a perfect elasto-plastic solid when the disk is in the limit state it is chosen the condition that the plastic deformations inside the disk side surface are equal to zero. For the model of a perfect rigid-plastic body in order to define the displacements as single-valued the displacements values inside the side surface of the disk are needed to be determined. Plots of numerical calculations for the stresses, the deformations, the displacements and the stress vector hodograph have been introduced.
Keywords: the plane-stress state, Mises yield criterion, the limit state, a rigid-plastic body, an elasto-plastic solid, a rotating disk, a stress vector hodograph
The сonstruction industry in Russia is conservative, new technologies, including information, are introduced with difficulty. Modern modeling technologies open up new resources in the effective management of information flows in the construction industry. Communication between architects and builders at the level of information model is difficult: different modeling systems have their own file formats. The methods of combining different parts of the model in a single environment: a single language description, direct interfaces, the creation of a single platform. The article describes the possibilities of BlockChain technology in the implementation of building information modeling technology. Evaluation of the feasibility of using BlockChain showed that the use of technology is relevant for a growing number of participants.
Keywords: building information modeling, BIM-technology, BlockChain, information security, unified information platform, data transfer technology
In this article there analyzed the three step approach in a modified spectral characteristics evaluation method using discrete transformations of Walsh and method of parametric spectral analysis of Proni. There briefly described the method based on the method of parametric spectral analysis of Proni, describing the positive and negative qualities. It is also proposed to apply a discrete change of Walsh and Hadamard. There suggested the use of three step procedure. Applying of Walsh discrete transformation will simplify and reduce the computational procedures. When applying these transformations for analysis of mathematical models of processes with similar characteristics, it is proposed to calculate the templates, and then to compare these templates. And templates for each group are invited once to calculate parameters using a modified Prony method or Prony and Berga combined method. Later on using Walsh transforms it is necessary to compare the results obtained with the available templates.
Keywords: modeling, spectral analysis, Proni method, method of Walsh, the model order discretization step response duration
One of the main sources of electromagnetic radiation in the environment are power lines, not taking into account this fact, there are increasingly cases of construction of buildings in close proximity to the boundaries of the security zones of air lines. The purpose of this study is to improve the electromagnetic safety of the population, as a result of the use in the construction of residential facilities located near overhead power lines, structural and finishing materials with the greatest shielding ability. On the example of "corrugated Board" of different brands, used as a shielding material, the indicators reflecting the efficiency of electromagnetic shielding are obtained. Also, according to the results of the study, it was found that not only the raw material from which the material is made plays a role in the shielding of the electric field, but also its form factor.
Keywords: electromagnetic radiation, electric field, security zone, shielding ability, voltage class, power line, material
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
The use of polymer concrete sleepers based on rubber concrete (RubCon®) with non-metallic composite reinforcement and the method of manufacturing such sleepers are described.
Keywords: sleepers, polymer concrete, rubber concrete, composites, reinforcement, manufacturing methods
On the basis of the model of non-piston displacement of oil with water, a mathematical model, algorithm and software product are presented, which allows to conduct numerical studies of the indicators of the development of a layered layer, taking into account the method of flooding the field: reservoir water temperature or hot water.
Keywords: continuity equation, heat transfer equation, non-piston displacement of oil by water, finite-difference scheme
The authors conducted field studies of a sequential series of breakdown voltages of the ignition system of the engine ignition model F8CV of the Daewoo Matiz car idling at a minimum crankshaft speed (650 rpm). The experiments were conducted on the basis of a microprocessor system for studying the distribution of breakdown voltage values. In addition to the distribution over the ranges of breakdown voltages, the algorithm of this system allows you to record a series of breakdown voltages in the microprocessor RAM. It was revealed that a sequential series of voltage values can: increase several cycles (no more than 3 cycles); several cycles to decrease (no more than 3 cycles); stay the same. It can be assumed that there is a correlation between the breakdown voltage and the maximum cycle pressure. A further research objective is to identify the patterns of change in breakdown voltage in a sequential series of breakdown voltage values.
Keywords: ignition system, spark discharge, internal combustion engine, spark plugs, breakdown voltage, histogram
Finite state machines, being a mathematical abstraction, allow you to perceive information from the control object, process it and give signals to control the object. The disadvantages of the representation of complex production systems by a set of finite state machines include the complexity of carrying out logical and set-theoretic operations on them and the complexity of describing the parallelism that occurs in the operation of complex production systems. When specifying a finite state machine in the matrix–predicate form, due to the information redundancy, it is possible to avoid these difficulties. Matrix–predicate method allows you to uniquely set the finite state machine square matrix, which makes it possible to use the methods of the theory of matrices during the set–theoretic operations on them and it is possible to avoid isomorphism. The paper presents the developed methods of representation of a finite state machine using a multi-place predicate, which greatly simplifies its task.
Keywords: finite state machine, graph, matrix, predicate, algorithm, matrix–predicate method, graph incident, tuple, Cartesian product, complex production systems
The paper deals with the derivation of the basic relations of the theory of finite rotations. A numerical study of the dependence of the guide cosine of the final rotation on the guide cosines of a fixed coordinate system and the coordinate system associated with a solid is carried out. The formulas for the cosines of the angle of final rotation are obtained. The developed program of calculation of the values of the guides of the cosines of the final turning of the quantities in the problem statement. A graph of the dependence of the guide cosine of the final turn on the sine of the angle of the final turn. This dependence is clearly displayed when the program is started.
Keywords: vector orientation in space, spherical trigonometry, finite rotation angle, guiding cosine, Euler angles, finite rotation
This work is a description of the method of restoration of patterned woven fabric by means of computer technology. The problem of computer reconstruction of a historical object is rarely addressed in scientific publications. However, now the question of the feasibility of prototyping and modeling in the digital space is significant, because it is a computer model that allows you to give an accurate idea of the task, of problem situations, helps to warn about possible or already occurred errors.
Keywords: textiles, computer technology, raster editor, digital restoration, macro, processing, restoration, pattern, pattern, fabric