The paper deals with the study of the dynamic characteristics of the coating farm. Due to the changes in the company's technological regulations, it became necessary to install additional ventilation equipment with its output to the roof of the shop. The study showed that to ensure safe operation in the structural scheme of bearing structures it is necessary to organize additional units. Dynamic load on the supporting structures is created by the operation of ventilation equipment. The spectrum of natural oscillation frequencies is determined. The values of these frequencies were compared with the frequency of forced oscillations of the fans. Graphs of the changes in natural frequencies when the fan operating frequency. According to the chart, when the frequency of the driving force coincides with the frequency of natural oscillations, the inertia forces increase sharply, which indicates the passage of the resonance zone. A study of changes in dynamic forces due to rotor imbalance was conducted. The value of the gap arising at wear of bearings at which there will be a destruction of a basic element of a farm was calculated.
Keywords: vibrations, forced vibrations, frequency, resonance, truss
The article is devoted to the analysis of emergency situations related to the damage of gas-insulated switches on ultrahigh-voltage lines. The results of mathematical modeling of aperiodic oscillatory process produced in the Simulink system, which occurs when a high-voltage power line containing shunt reactors is switched on under the nominal voltage, are presented. The variants of using a switch with a set of pre-switched resistors in order to minimize the destructive influence of the aperiodic process that occurs when an overvoltage pulse occurs are considered. The results of the simulation of the switching process in the application of high-voltage switches with a set of pre-switched resistors. The simulation was performed on the parameters of the current transmission line with a nominal voltage of 500 kV on the site of the substation "Eletskaya" - nuclear power plant "Donskaya".
Keywords: shunt reactor, aperiodic process, high-voltage power lines
At present, there is a tendency in Russian society, which is connected with the fact that modern people strive, first of all, for self-realization. Very often, in the process of forming career strategies, a person thinks about whether he is happy in his position after having worked in an organization for over a year. Sometimes, such thoughts force a person to change the type of activity or completely change the place of work. Thus, such a pattern of behavior as downshifting can be formed, when a person radically changes the quality of his life, life priorities and value orientations. The author of the article, in connection with such a change in the model of career behavior, considers the reasons that can influence the reorientation of value orientations from material to spiritual.
Keywords: downshifting, career downshifting, success, values, profession, income, chronic fatigue, yuppie, freelancing, family, freedom
Numerical modeling of the temperature distribution during heating (annealing) by a pulsed Nd: YAG laser of an amorphous silicon (a-Si) film on the surface of an AZO glass substrate is carried out. The simulation was performed on the basis of a numerical solution of the heat equation in the Matlab program to determine the energy density of the laser radiation necessary for crystallization of the a-Si film. For a wavelength of 1064 nm, it was obtained that the temperature at the surface of the a-Si film reaches a maximum value at a time point of 146 ns with a laser pulse with a Gaussian time-shape. It is shown that for the crystallization of an a-Si film with a thickness of about 800 nm with laser radiation with a nanosecond pulse duration, the optimum energy density is 600-700 mJ / cm2 when the temperature across the thickness of the a-Si film corresponds to 550-1250 ° C.
Keywords: Numerical simulation, laser annealing, temperature distribution, a-Si film, solar cell
This article will analyze the effect of Gc on the propagation of cracks in glasses with different material properties. The analysis demonstrated that with decreasing Gc, the crack length will increase and, with a larger applied force, the effect of Gc on the crack propagation in the structure decreases.
Keywords: fracture mechanics, fats fracture, Gc, crack propagation, Code_Aster, Solome Meca
The article presents a theoretical description and procedure for calculating the three-hinged arch parabolic outline. The technique of creation of the universal program in a computing complex of Mathcad for various options of vertical loading is in detail stated. The method of calculation of a three-hinged statically determined arch is considered in detail. The order of design calculation is given in the article. The technique of the automated creation of diagrams of internal power factors of an arch design is offered. A detailed description and analysis of the design scheme of three-hinged arch is given.
Keywords: three-hinged arch, statically definable arches, arched structures, parabolic outline, diagrams of internal power factor
The paper describes the process of developing a web application that contains audio content. When designing the system, the methodology of OOAP (Object-Oriented Analysis and Design) and the MVC (Model View Controller) design pattern were used. With umbrello, canonical UML diagrams are constructed, describing various aspects of the system being modeled. Based on the diagrams created, the application was implemented using the java programming language. Also, the user interface is made, allowing to demonstrate the capabilities of the application. The developed application should be a multi-page client-server application with the ability to listen to music and create playlists based on their preferences.
Keywords: web application; audio content; methodology of object-oriented analysis and design; UML - chart; java programming language
The article is devoted to the close studying of heat transfer and hardening of the ingot in the secondary cooling zone (further SCZ) in the continuous casting machine (further CCM), and also determining a stress-strain state of the ingot including continuously varying temperature field inside it in order to prevent the process of buckling the ingot by setting rollers in the center of the largest displacements and deformations and as a consequence of reducing the length of the roller section. This aim is achieved through the development of methods of calculation of the stress-strain state of the ingot in a CCM with a help of the temperature object decision, correct selection of the approximation model of the experimental data and the selection of finite element-based on the Lagrangian description of motion of a continuous medium and comparison the calculation results for multiple selected sections.
Keywords: continuous casting machine, ingot, hardening in the secondary cooling zone, rollers, heat-exchange
The article discusses the results of the development of a methodology based on the principles of subject-augmented management for choosing a contractor in construction when placing orders for contract bidding to meet state and municipal needs. The considered methodology is based on determining criteria for evaluating bidders for contract bidding, processing expert information, translating quality indicators into qualimetric units of measurement, and also modeling the preferences of bidders. The principle of subject-oriented management, on which this methodology is based, involves the use of a non-manipulated mechanism. The application of this methodology on the principles of subject-oriented management becomes relevant when the individual with different preferences is involved in setting the minimum initial contract price. The urgency of finding methods for objectively selecting the winners of tenders in construction is due to the established practice of allocating government contracts through an auction mechanism, where the only criterion for determining the winner is to offer a minimum cost of work, which directly affects the quality of work performed and services rendered. The study of the relevance of the investigated problem revealed the fact that to evaluate and account for technical and technological solutions used to select the winner of contract bidding it is necessary to use qualimetric methods based on non-manipulable mechanisms - exclusion of any kind of manipulation of the results of the bidding in their interests. The technique describes the concept of contract bidding. A system of criteria is proposed that is most fully capable of evaluating the participant’s application. The criteria can be divided into three groups: the first group describes the motivation of the participant, the second group evaluates the tender proposal, separately allocated the contract price.
Keywords: contractors, municipal order, subject-oriented management, non-manipulable mechanisms, contract bidding in construction, integrated assessment, integral indicator
The problems of synthesis of a model of dynamic neuron with state memory (DNSM) are considered in the paper. The introduction of a special additional parameter into the model of a neuron, defined as a state parameter, is substantiated. It is indicated that the parameter of the state of the neuron has the ability to vary with time depending on the nature of the information processes that occur in neighboring neurons of the network. This parameter in a certain way accumulates information about the history of the behavior of the neuron in accordance with the entered formal descriptions. The concept of a "strained neuron" is introduced, taking into account the above. This concept characterizes the degree of influence of a given neuron on the neurons surrounding it. On the effects of time-varying parameters of the state of neurons, it is proposed to implement the process of self-evolution of the network directly during its operation. A variant of the analysis of the structure of the neural network, created on the basis of the proposed model DNSM. The topological representation of a neural network in the form of a graph model allows formalizing the interaction of neurons in a network with each other, both in time and in space. For this, the concept of k-space is introduced, which determines the degree of proximity of neurons to each other. The degree of proximity of neurons allows one to formalize, in the form of mathematical relationships, the procedure for the exchange of information between neighboring neurons in a network. Mathematical relationships that formalize these processes are given. A variant of the structure of the hardware design of DNSM, focused on implementation using FPGA technology, is proposed.
Keywords: dynamic neuron with state memory, connectionist model, self-evolutionary mechanism
Predictive assessment of the technical object is based on the determination of the possible values of the controlled parameters in the projected time period and is carried out during the operation of the object. Calculations are usually done in the background and it is important to estimate the minimum sample of parameter values that can be used for prediction. The article shows the possibility of using the Hurst indicator to determine the persistence of the time series of the object parameter and presents a scheme for estimating the minimum sample size, which can be used to reliably predict the parameter change using time series forecasting methods.
Keywords: time series, Hurst exponent, forecast, estimate, trend, stability, persistence, value, parameter, object, data array
Today one of the topical issues is the practical application of the theory of pattern recognition, face recognition, including the definition of a person in the image and its subsequent identification. Such tasks include the extraction of indirect signs of interaction between users of social networks. By identifying the user's face and further searching it in photographs and video files in other profiles, an expansion of the list of basic data available to the analyst is achieved. It is known that the system of computer vision, which is able to recognize faces in a natural and artificial environment under any conditions, has not been implemented to date. One of the obstacles is the variation of the scene - the area where the face is being identified. The article proposes a model of an intelligent information system using bion-spirited methods for preprocessing images in order to expand the range of allowable scene variations.
Keywords: pattern recognition, object identification, photometry, intellectual system, social networks, analysis
A nonlinear boundary value problem on the propagation of surface waves in a layer of viscous incompressible fluid of infinite depth is considered. Equations of motion and boundary conditions are written. The solution of the problem is found by the small parameter method. An expression for the damping decrement of the wave oscillations is obtained. The program code in C++ for the numerical study of the propagation of nonlinear waves on the surface of a viscous liquid is developed.
Keywords: viscous liquid, slabowska fluid, nonlinear surface waves, the damping rate of waves, phase velocity, frequency wave
This study examines the dynamics of the perception of individual segments of the advocacy news. A probabilistic-stochastic approach for simulation is proposed. As the main actor describing the situation, the probability of a positive assessment of the veracity of the new information by a separate subject is taken. For the description of the process of forming the relation to it the discrete-event paradigm is chosen. The change in the level of evaluation occurs under the influence of random perturbations of the individual's opinion, experienced at discrete moments of time. An intuitive recalculation after this perception of the news is modeled based on Bayes ' theory of decision making. Mathematically, this approach fully coincides with the previously used by us in the numerical analysis of the resolution of intrapersonal conflicts. The results revealed at that time were adapted to study the dynamics of the perception of propaganda news by a neutral part of the population. Which is made by the individuals estimating truthfulness of propaganda activity as a whole neutrally, at the level of ½ (on a scale from 0 to +1). It is found that when assessing specific news such neutrality is violated, in the end, the individual believes the news is either completely true or false. But it is already being restored at the level of the ensemble of all news. About half of them are considered by the individual to be true, half – false. The time before the formation of the final perception of a particular news depends on the degree of its importance for the subject, and the minimum is observed at the level of significance slightly below the maximum. The model of taking into account the social environment in the resolution of intrapersonal conflicts has also been adapted for the analysis of the perception of propaganda information. While the assessments of the credibility of the individual stories of neighbors are correlated. Over time, clusters with the same perception are formed in society. Ideally, in the absence of other influences, eventually one opinion is formed in the whole study group. Here again, for some propaganda news, the neutrality of perception is broken, but it is restored at the level of the ensemble of all news. The proposed models can be used to study not only the neutral part of the population, but also groups with any level of assessment of the truthfulness of propaganda in General, both homogeneous and heterogeneous in this parameter. In addition, the proposed approach can serve as a basis for the study of the impact of agents of influence (in the information space) and the development of advocacy strategies.
Keywords: propaganda, perception, in General, separate news, modeling, probabilistic-stochastic approach, discrete-event approximation, Bayesian theory, multi-agent analysis, social environment, clustering
This article analyzes the stress-strain state of exploited reinforced concrete crane beams in order to identify the causes of abnormal damages. Also, the degree of influence of the revealed damages on safety and operational fitness was assessed.
Keywords: crane beam, technical condition, operational availability, defect, durability, damage, inspection, discretization, stress-strain state