This paper presents two methods of computer simulation (quantum chemical analysis and molecular dynamics) of the interaction of additives with the iron surface. Quantum chemical interaction of silicate and phosphate additives with iron surface was carried out. The plate model was used for quantum chemical analysis, calculations were carried out in the DFT approximation. The method of molecular dynamics is based on the calculation of the evolution of the system of interacting particles of atoms and molecules by integrating the equations of their motion. It is shown that the oxidation of the surface leads to a decrease in the adhesion energy of both individual additives and their combinations, allowing to find the influencing factors on the behavior of tribosystems.
Keywords: lubricant, method, quantum chemical analysis, molecular dynamics, tribology, friction, computer simulation
Assessment of influence of speech intelligibility and reverberation time on the quality of acoustics Determination by theoretical method and computer simulation method of reverberation time in the modern audience and the audience, built more than 10 years ago. Determination of sound absorption coefficients of surface materials in both classrooms. Modernize of classrooms using wood fiber panels to increase sound absorption and reduce reverberation time. As a result, the reverberation time of the upgraded audiences has become less than one at all frequencies. This ensures good speech quality and efficiency of the educational process.
Keywords: acoustics, classroom acoustics, reverberation time, speech intelligibility, sound absorption coefficient, computer simulation, wood fiber
The article provides an overview of the methods of automatic abstracting and annotating documents. The description of classification of methods of annotation and abstracting on various criteria is presented. The algorithm of automatic annotation is described in detail, the key step of which is the transformation of all words in the text into lemmas (lemmatization). The developed program sets the upper limit of the output annotation in order to avoid receiving the abstract instead of the annotation.
Keywords: annotation, abstracting, lemmatization, algorithm, software implementation, database, text analysis
The technique of improving the quality of remote diagnostics of cars is proposed. This method makes it possible to learn real-time and real-time information about the status of the functional units of the car, thereby assessing its technical condition.
Keywords: remote diagnostics, car service, car
Progressive collapse - or, in particular, an understanding of the mechanics of this phenomenon and the development of ways to consider it in the framework of structural design - can be regarded as a relatively new topic in building science. The article describes the background to the emergence of this topic, ranging from local examples of the collapse of buildings and ending with the well-known collapse of the World Trade Center. Analyzed the latest world research in this area and revealed inconsistencies in the requirements of regulatory documentation and the real work of the building frame in case of progressive collapse
Keywords: progressive collapse, durability, steel frame, multi-storey buildings, connections stiffness, ductility
The urgency of estimating the content of nitrates in food products to ensure environmental safety at an individual level is discussed in the article. Data on the negative effect of increased nitrate content in plant foods on human health are given. The results of the study on the determination of the content of nitrates in food products using a household nitrate counter "Soek nuk-019-2" are discussed. This device makes a conclusion about the concentration of nitrates by comparing the reference electrical conductivity of different types of vegetables / fruits with the electrical conductivity of a particular controlled product. It is determined that exceeding the MPC is observed in potatoes and onions, which are sold through a network of stores that occupy leading positions in the prevalence in Taganrog. Excess of MAC in carrots is observed only in its central part (core). Based on the results obtained, practical recommendations are given to ensure the safety of food consumption.
Keywords: food safety, food, nitrate content, household nitrate
The problem of synthesis of the speed regulation law and the angle of rotation of a crawler platform with DC electric drives in a nondeterministic medium is discussed. The solution of the task is achieved by using a synergetic controller with a hierarchical control principle. The crawler platform control is considered on the basis of the mathematical model of platform motion and electric drives
Keywords: synergetic control theory, ACAR method, hierarchical method, integral adaptation, crawler platform, DC electric drive
Noise pollution is an ecological problem of big cities. Noise can reduce the working capacity of city residents and cause various diseases, so combating it is the most important event for ecologists, doctors, builders and other stakeholders. Studying the ability of plants to absorb noise will allow you to plan the future of the city’s territory. Examining the ability of green roofs to absorb noise will solve the noise problem in places where creating additional landscaping is possible. As a result of studies revealed green cement capable of reducing the noise level in the premises to 1.5 dB greater than the conventional roof. Based on the work carried out, a systematic approach has been proposed to solve the problem of noise pollution in the urban environment in the North by creating various types of green roofs on roofs with a slope level of less than 30 °.
Keywords: noise pollution, plants, green roofs, noise-attenuating ability
The article describes the algorithm of recognition of schematic diagrams in the framework of structural design of complex technical objects. It is specified that at statement of a problem of development of the specialized vectorizer it is necessary to define: software subsystems of the simplest tracer; algorithms of the analysis of images; formats of representation of the end result; initial data (formats) for recognition. As a result, it was concluded that for structural and circuit design, during which the vertex of the final portrait of the graph of the projected system is replaced, obtained after optimization by the criterion of the set of the smallest external stability, it is necessary to recognize images of graphic elements. The proposed algorithm allows for adequate recognition of the elements of electronic circuits, which further makes it possible to automatically replenish the database of elements with new elements in a given format.
Keywords: vectorization, concept recognition algorithm, structural design, graphic, element, raster image, electronic circuits, semi-graphical display, block-the functional distribution of the tracer
The article highlights the use of information technologies in modern education. The opinion of modern didacts has been generalized and presented, and the methodology for presenting information allows the most effective presentation of educational material. The economic component of application of information technologies in higher educational institutions is considered. The peculiarities of the realization of the educational process are considered taking into account the impact of computer radiation on human health. The most important indicators of the effectiveness of the use of information technology are revealed.
Keywords: information technology, distance learning, communication technology, economic component of IT, aim IT, quality
The article examines the problems of construction and design of buildings and structures in tropical areas of Vietnam, formulated the principles of their construction. It demonstrates that the comfort principles are correlated with the corresponding composition techniques and methods are implemented in a system architecture approach Urbanized shaping medium using methods lighting calculations that take into account parameters of the light and climate conditions insolation simulation method for building layouts.
Keywords: construction, design, tropical areas, solar radiation, insolation, sun protection devices, light climate, cloud statistics, structures, architecture, design
This article describes the relevance of geodetic control. Briefly describes the existing and proposed methods of geodetic control. Also the special device for geodetic researches of industrial buildings and constructions is offered. This device is attached to the geodetic rail, it is fixed laser rangefinder. With this device it is possible to perform geodetic survey of building structures of an industrial building or structure without fixing reference points. The technical task of the claimed device is the joint use (fixation) of the standard laser rangefinder and geodetic rack due to the constructive execution of the device, in the production of geodetic works to determine the deflections of supporting structures of industrial, public and residential buildings. For verification of the claimed device was carried out surveying work for determining deflections of the roof trusses of an industrial enterprise. Conclusion: labor costs of geodetic works were reduced in comparison with traditional methods by an average of 20 – 30%.
Keywords: geodesy, laser rangefinder, survey rail, survey, device, building, structure, plate, bolt, thread, size
The accuracy of various models used to study inverse saturable absorbers is investigated in this paper. An exact solution of the problem of propagation of laser radiation through a medium with reverse saturable absorption is presented for the case of propagation of light signals with energy equal to the saturation energy in media without relaxation. We consider the case when a pulse of Gaussian shape. With an exact solution, the result of a numerical calculation of the transport equation and Bouguer's law is compared for the intensity of the accuracy realized by different methods of different accuracy. The paper is considered very small extent environment compared with the linear dimensions pulse. Schemes 1-4 of the order of accuracy for these two equations are constructed. For eight different schemes, approximation errors are given. It is shown that already with the use of third-order schemes for a laser pulse of 0.1 J the numerical solution differs from the exact one by only a few nanojoules. Thus, when studying the effect of RSA in large-sized carbon particles, substances where the effect is observed only at energies <1J, the use of third- and fourth-order methods may be unnecessary, especially when using a rather small step.
Keywords: numerical methods, transport equation, approximation, reverse saturable absorption
The construction of mathematical models of objects of experimental or computer simulation is associated with the mathematical processing of experimental data. The point dependences of the output variables for the input variables obtained for them are essentially nonlinear, piecewise, sometimes discontinuous. Approximation of such dependencies using polynomial expansions or spline functions is both difficult and involves large errors. A fundamentally new solution to this problem was proposed in the article. This method, called the "Cut-Glue" approximation method, is based on the partitioning of the modeled dependence into sections, the approximation of each section by polynomial dependencies, the multiplicative "excision" from each dependence of the fragments along the boundaries of the plot and the additive "gluing" them together into a single function - the model of the approximated dependence . The analyticity property of the resulting function allows to study the model and use it in models of vehicle dynamics. One of the stages of the "Cut-Glue" method is the "Glue" process - the additive "gluing" of fragments into a single function. For this, an auxiliary multiplicative function is used. The function of this function includes the steepness of the pulse fronts. In this paper, a developed modification of the method of burrowing particles is used in the problem of research and suboptimization of this parameter. As a test bench of the developed algorithm developed a special software tool.
Keywords: optimization, approximation, mathematical model, experimental data, heuristic methods, the method of burrowing particles
The article considers the application of a modified two-stage genetic algorithm to solve the traveling salesman problem. The traveling salesman problem is a classical combinatorial optimization problem known since 1930. The traveling salesman problem is NP-complex. With the number of cities 66 or more, it is impossible to solve it by exhaustive search. To test the proposed approach to the solution, we consider a graph with 51 vertices from the package TSP_LIB. At the first stage, a modified Goldberg model with small parameter values works to obtain the first generation of the second stage with better performance than the random formation of individuals. The second stage works with increased values of genetic algorithm parameters. These values vary from experiment to experiment, the results of which are presented in diagrams. Also, the results of the two-stage algorithm are compared with the results of the one-stage algorithm. A modified Goldberg model of the genetic algorithm is used. The genetic algorithm uses a waypoint representation of a traveling salesman's route with a two-point ordered crossover and a "greedy" mutation. The experimental results showed the effectiveness of the proposed approach. The modified two-stage algorithm allows to obtain a solution close to the optimal one.
Keywords: traveling salesman problem, genetic algorithm, Goldberg model, crossover, mutation, individual, route, Hamiltonian cycle, distance matrix