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
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 paper considers major approaches of digital images tone approximation, which consists in reduction of image palette size, and their classification. The main drawbacks and advantages of each approximation method are discussed. Also discriebed hybrid algorithm of monochrome images tone approximation that developed and investigated by author.The hybrid algorithm consist in combination of heuristic and deterministic approach. The heuristic stage is based on evolutionarily-genetic algorithm. The main goal of heuristic stage is reduction the area of searching. Such a role for heuristic stage defined according to his fast computational time. The goal of deterministic algorithm consist in finding a nearest extreme for the result that obtained by previous algorithm. The results of comparative investigations are discussed.
Keywords: tone approximation, optimization, monochrome images, evolutionary-genetic algorithm, k-means algorithm, color quantization, median cut, images compression, pattern recognition, images approximation, images processing
The article presents data on the effect of external composite reinforcement of reinforced concrete columns on their deformation properties. It is established that the results of calculations of the reinforced samples according to the deformation norms in force have significant discrepancies with experiment. Based on the analysis of the results of experiments, proposals have been introduced into the normative calculation of deflections, which take into account the type and percentage of composite reinforcement and ensure good agreement between the experimental and theoretical data.
Keywords: concrete, reinforced concrete, composite material, carbon fiber reinforced plastic, external reinforcement, deformations, deflections, compressed elements
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
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 deals with the issues of dispersion of heterogeneous liquids by spray nozzles in order to divide them into components. The influence of various parameters on the size of the droplets obtained is investigated. For the mathematical description the probabilistic approach is applied, which allows to obtain a differential function of the particle size distribution, which can form the basis of the engineering method of calculation of this class of separators. An expression for determining the average value of the angular velocity of the internal flow is compiled. These dependences allow us to calculate the most probable value of the angular velocity corresponding to the decay of complex drops into secondary ones, which are the drops of the initial liquids.
Keywords: particle, emulsion, non-uniform liquid, droplets, jet, nozzle, velocity, flow, parameter, separator
The basic methods of economic indexes forecasting on railway transport enterprises have been defined in the article. Three stages of forecasting were determined and described in details. The dominant elements of expenses, such as job salary, traction costs, insurance, repair capital and others were taken into account during research.
Keywords: railway enterprises, operational expenses, economic indexes, forecasting, quantitative assessment
With the help of the previously developed application Plex, automation of planning and conducting multifactor experiments in the study of the characteristics of field-effect transistors was performed. The regression and dispersion analysis of experimental data is carried out, the quality of regression models is estimated, the influence of the number of initial experimental points on the quality of regression models is investigated. The application increases the efficiency of research related to field experiments in determining the characteristics of field-effect transistors, as it makes it possible to reduce the number of required experiments, to automate the processes of storage, extraction and processing of information.
Keywords: planning, factor, experiment, field (unipolar) transistor, application, regression, dispersion, prediction, approximation, simulation
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
It is proposed to use energy efficiency as a criterion for optimizing of wood fuel production when comparing different technologies with the help of simulation modeling. The results of the calculation of the specific consumption of energy resources per unit of produced fuel chips are considered under the processing technologies under consideration. The costs of energy resources are taken into account starting from the stage of harvesting of low quality fuel wood in the cutting area, ending with shipment of fuel chips to the consumer. The energy efficiency of the considered technological process for the production of fuel chips with the help of a system of machines consisting of an feller buncher, a mobile wood chipper and a chip transport machine accounted for 93.76% with a chip transport distance of 50 km, the energy intensity of the product was 7.949 tons of fuel equivalent for 1 thousand dense cubic meters of fuel chips. The offered technique allows to make the comparative estimation of power efficiency of various technologies of manufacture of fuel chips.
Keywords: fuel chips, production technique of wood fuel, optimization criterion, energy-output ratio, energy efficiency
For the successful operation of enterprises in an unstable economic situation in our country, it is necessary, first of all, competent management of operational trade accounting, allowing you to quickly navigate in difficult market situations and make informed management decisions that reduce commercial risk. In these conditions for any organization the task of creation of effective system of supply of raw materials at the enterprise is actual. The article presents an example of qualitative evaluation of the competitiveness of the supplier.
Keywords: quality management system, process, supplier, generalized indicator, weighting factor, competitiveness
The paper presents a method for decomposition of a complex dynamic system with a network architecture based on the Crohn's diakoptic approach. The proposed method is aimed at the allocation of independent network segments, the removal of which from the general structure will not affect the overall performance of the system. Segments are formed as simple paths in the graph model of the system with the least weight of the incident edges and checking the condition for maintaining the product flow balance in the application to the transport task. In general, the decomposition method presented allows us to divide a complex technical object of the network architecture into subsystems, simplifying the process of analysis and management. In the case when the common control task and the dynamics of interaction of subsystems allow the system to be broken up into unconnected segments, or to limit interaction over certain lines, the method allows reducing the load on the transmitting elements of the system.
Keywords: decomposition, complex dynamic system, network, grapho-analytical method, network segmentation, diakoptics, load reduction
Type-2 Fuzzy Logic Controllers do not have the disadvantages of Conventional Fuzzy Logic Controllers, and are widely used in many control areas. However, using it to build embedded systems is accompanied by a large number of rules that increase the processing time and sometimes confusion, reducing the efficiency of the operating system in real time. To eliminate this disadvantage in the paper proposed the new structure of Type- 2 Fuzzy Logic Controller is proposed block based fuzzy controller to reduce the number of rules, and reduce the complexity and increase the reliability of the system control. The proposed controller is based on a fuzzy mass with a small number of fuzzy rules, due to the reduced number of input and output variables. The advantages of the new fuzzy controller are illustrated by the example of the embedded control system of the Self-Balancing Robot. The performance comparison of the proposed block based fuzzy controller shows that the rules of Type-2 Fuzzy Controller is less than twice the number rule of the conventional Type-2 Fuzzy Controller. This increases the yield by 45%, proving the feasibility of the actual application of the proposed controller
Keywords: fuzzy controller, type-2 fuzzy logic system, embedded system, self-balancing robot
The methodology of regression mathematical description of fragments of experimental data of arbitrary dimension by polynomials necessary for a given accuracy of order and structure is considered with the help of a hybrid of classical regression analysis and a modified evolutionary genetic algorithm through which the polynomial structure is varied and optimized.
Keywords: optimization, approximation, regression analysis, mathematical model, experimental data, heuristic methods, evolutionary-genetic algorithm
The article proposes an algorithm for the functioning of adaptive motion control systems of a group of mobile transport robots in conditions of uncertainty. The algorithm was developed based on the Markov method of identification and the method of analytical synthesis of systems with control by output and effects. The adaptive control system in which this algorithm is used has direct quality indicators not worse than those specified. The proposed algorithm can be used to create control systems for technical objects of various types, with previously unknown mathematical models.
Keywords: mobile robot, group, uncertainty, identification, Markov parameter, control by output and effects, system
The article is an insight into the history of the use of the term "limitrophe" in Russian literature on geopolitics. The etymology of this term is considered in detail. It turns out, who and when for the first time in the literature used it, putting a geopolitical sense. Shows the General historical background of the era (1920-1930) when the "border States" were widely used by many authors in the Soviet Russia/USSR and in the Russian Diaspora. Examines the question of when and why the second "coming" of the term "border States" in the Russian geopolitical literature. In the context of the collapse of the Soviet Union and the Pax Sovietica shows how has changed geopolitical interpretation of the term "limitrophe". In this regard, given the outline of the concept of the Great Limitrophe.
Keywords: the global geopolitical space, regions, rigid clusters, intermediate space, border States, the collapse of the Russian Empire, the Baltic-black sea area
This work represents the third article within the cycle devoted to the peculiarities of the analysis of the situations in geopolitically unstable zones of the modern world. This time the author focuses on the second stage of the mentioned scientific procedure. He assumes the analysis of the dynamics of such zones (regions) as multifactorial combinatorics, with the dominance of the conflict nature of interstate relations and the key role (in some cases) of non-regional players. An attempt is made to present unstable regions and the same kind of limitrophic zones as a combination and overlapping of the force fields of a different nature.
Keywords: modern world, geopolitically unstable zones, separation belts, limitrophic zones, interstate relations, multilateral and vertically organized, conflictness, asymmetrical conflits, international mediation, force fields
In this research work the analysis of the development of the concept of "smart cities" is carried out on the example of cities in Europe and Africa, also on Russian facilities. Based on the results of the research, the main principles affecting the formation and development of effective urban space are revealed. Also, the shortcomings that destroy the very concept of "smart city" were analyzed.
Keywords: smart city, innovative technologies, information systems, energy efficiency, renewable energy sources, transport equipment, urban space lighting, satellite cities, science cities.
The article is devoted to the study of the problem of determining the mechanical properties of vibrating centrifuged concrete with a combined aggregate and fibrous additive, which was basalt fiber. Experimentally obtained data on the optimal consumption of disperse fiber. The dependence of the strength properties of concrete with a combined aggregate on the amount of fiber additive added is graphically presented. Also graphically shows the increase in the speed of the passage of an ultrasonic wave in the body of concrete when determining the prismatic strength. It was found that the presence of porous particles in a concrete mixture facilitates the directed distribution of mineral fibers along the section of the concrete ring. This, in turn, leads to an increase in the fracture toughness of the material. The conclusion is made that the joint introduction of porous and fibrous additives into the concrete mix determines the production (at the same cement costs) of high-strength concretes with an increased crack resistance, as evidenced by the data on the displacement of the boundaries of microcracks formation in the direction of their increase.
Keywords: structures and products of annular section, centrifuged concrete, vibrocentrifuging, mechanical properties of vibrating centrifuged concrete, combined aggregate, fiber additive, basalt fiber, prismatic strength
The article is devoted to the study of foreign methods of waste processing and the use of secondary resources. The article also considers the peculiarities of the countries ' legislation in the field
Keywords: waste, secondary material resources, landscaping, recycling, electrical energy, solid residue, chemicals, leakproofness, incineration, filtration, organic, decomposition, recycling, energy efficiency, emission
The main problems of Russian transport infrastructure are considered. On the example of European experience the ways of solving these problems are proposed. The article also discusses in more detail the transport situation in the city of Rostov-on-don, what are the problems and how they can be solved in the near future.
Keywords: transport infrastructure, highways, Parking, concept, neighborhood, traffic flow, car, Parking, building, congestion, flow, disaster