The paper studies the issue of the influence of the quality of the computational triangular grid on the accuracy of calculations in various computational problems. There is a well-known example of Schwartz, which shows that the approximation of a smooth surface by a polyhedral surface can give very large errors for calculating the surface area. This is due to the quality of the constructed triangulation of the surface. Therefore, it is natural to expect that there is some connection between a certain triangulation characteristic and the accuracy of solving some computational problem. In the presented article, as such a characteristic, a value is chosen - the average value of the minimum sine of the angle of all triangles of the computational grid. In the course of numerical experiments, the Dirichlet problem for the Laplace equation in a circular ring was solved, in which the error of the approximate solution was calculated (the gradient descent method was used to find a solution to the corresponding variational problem.). For the ring, a series of triangulations was constructed with a uniform division along the angle and a non-uniform division along the radius in polar coordinates. In this example, a linear dependence of the error on was shown. The article presents both the results of the calculation with different values and the calculation of the correlation coefficient of the studied quantities.
Keywords: boundary value problem, Delaunay triangulation, calculation accuracy, Dirichlet problem, mathematical modeling, triangular mesh, minimum triangle angle, piecewise linear approximation, variational method, Laplace equation
The paper presents the results of engineering and environmental surveys at the object of accumulated environmental damage - an unauthorized dump on the territory of the Shuvalov industrial zone in the Leninsky district of Nizhny Novgorod. A description of the study of the territorial and natural features of the object is given: landscape, representatives of flora and fauna, as well as data from laboratory studies of soil samples. An analysis of the morphological composition of the waste and data on the volume and mass of the disposed waste are presented. The level of microbiological, parasitological, and chemical contamination of soil samples with heavy metals is assessed. For carrying out reclamation work at the site, the authors of the work propose a composition that includes natural mineral-organic compounds. The results of the laboratory application of natural mineral-organic compounds with the production of soil-recultivator from the screening of landfill masses are presented.
Keywords: industrial and consumer waste, engineering and environmental surveys, unauthorized dumping, soil pollution, heavy metals, technogenic soil reclamation, reclamation soil
Transportation is one of the most important stages in the management of cement delivery, which accounts for 60% of total costs. Thus, a slight improvement in the collection and processing of data on the operation of concrete mixers can have a significant impact on the overall savings spent on the work of companies engaged in transportation. On the other hand, the movement of heavy vehicles carrying cement mixture leads to the spread of air pollution and damage to the road surface in case of excessive loading. Therefore, the issue of determining the route of the vehicle to achieve this goal is very important. In this study, the routing process of concrete mixers was modeled using random routing problems and genetic algorithms. The simulation results showed that the genetic algorithm converges to the optimal answer. On the other hand, the volume of the cost function decreases from 1,177,500 rubles to 158,900 rubles. due to the optimization of the mentioned model, and the performance result led to the appearance of the shortest possible path. With the help of the algorithm, all the parameters of sustainable development management are achieved, including reducing air pollution, reducing fuel consumption and reducing the destruction of the road surface. Finally, thanks to the integration of the GLONASS/GPS software, the output data of the algorithm was mapped to the map.
Keywords: optimization of routes, fuel efficiency, reduction of emissions, preservation of the integrity of the road surface, optimization, logistics, modeling, special car, urban operation
The article deals with project management as one of the most important mechanisms of management in the system of market economy. In Russia, the field of project management, including construction, is actively developing, taking into account international experience and national peculiarities. Digital transformation of technological and business processes in construction is rather weak compared to other Russian industries, which is due to the specific activities of construction companies, during which the necessary data are not accumulated continuously, but are collected at different stages of the project. The experience of implementing digital technologies in the implementation of investment and construction projects is considered on the example of the experience of a federal construction company, whose branches are located in several Russian cities.
Keywords: construction, project, investment, digitalization, digital technologies, BIM technologies, online office, Bitrix24 service, 1C:PM Project Management, CORP, VIM-model
The article proposes a structural and functional model of the performance management system of Russian universities based on rating ratings. The system consists of four main integrated components related to each other: the Ministry of Science and Higher Education of the Russian Federation, national and international rating agencies, Russian universities and the unit for evaluating integral indicators of universities by type of activity. The particular indicators of the activity of universities that most affect the values of integral ones are determined. The key factors influencing particular indicators are identified. Such a structural and functional representation of the performance management system of universities allows us to apply statistical and simulation modeling methods for its analysis. The use of the proposed model will make it possible to predict the values of private indicators of the activity of universities, depending on the key factors of influence. This will allow the management of universities to make scientifically-based management decisions to improve the efficiency of the functioning of universities.
Keywords: performance indicators, scientific activity, publication activity, modeling, Scopus, Web of Science
This article discusses the results of environmental monitoring of the waste disposal facility located in the northern part of the Traktorozavodsky district of the city of Volgograd. The data on the territorial features of the investigated area, flora and fauna are presented. The morphological composition of wastes present in the soil is analyzed, as well as the results of laboratory studies. The results of studies on the content of heavy metals in the soil (bulk and mobile forms) and data on bacteriology (enterococci, bacteria of the Escherichia coli group, helminths, cysts of pathogenic intestinal protozoa) are shown. The authors put forward recommendations on the methods of reclamation of this territory.
Keywords: production and consumption waste, environmental harm, environmental monitoring, landfill, heavy metal pollution
In the automation of production, the use of robots is an important direction. When developing algorithms for controlling the movement of such a machine, multidirectional problems arise. In a critical situation, the robot must not harm workers or collide with its fellow robot. At the same time, the car must move along the optimal route. The article analyzes the methods of finding optimal paths on square navigation grids. The wave method on undirected planar graphs, the A* algorithm (an extension of Dijkstra's algorithm), and the D* Lite algorithm for graphs with non-constant or previously unknown structure were chosen for the analysis. A visualization and testing system in C#has been developed for the research and testing of algorithms. The system is implemented using the Microsoft Visual Studio 2019 IDE software tools and external GraphX and Emgu CV libraries. A unique feature of the system is the ability to directly read images of shop floor maps in widely used graphic formats and automatically convert them to a format that is understandable to the system. First, the user uploads the shop floor plan. For easier processing, the image is converted to two colors: black and white. Then the image is processed by the Emgu CV library, at the output we get all the contours of stationary obstacles. Then, depending on the size of the robot, an orthogonal navigation grid is superimposed. The analysis of the obtained results allows us to conclude that it is better to use a method (the D* Lite algorithm) that allows for a non-constant or unknown grid structure in advance.
Keywords: visualization, program, graphic format, work, shop, map, square, grid, cell, navigation, optimal route, planar graph
The work is devoted to the problems of using modern digital technologies to manage the implementation of programs for the development of regional socio-economic systems. An approach based on the use of intelligent (knowledge-oriented) informationsystems for monitoring and analyzing the progress of programs is proposed. As a model for representing knowledge about the subject area, it is proposed to use the apparatus of the theory of linguistic variables and fuzzy production rules, which makes it possible to take into account the high level of uncertainty due to both the specifics of socio-economic processes and possible changes in external conditions. The inference engine included in the information system is based on the explicitly interpreted procedure of Mamdani's fuzzy logical inference, which makes it possible to form explanations of the course of reasoning. The developed structure of the intellectual information system is a concretization and expansion of the traditional structure, taking into account the reflection of the specifics of the tasks of managing the implementation of programs for the socio-economic development of the region. The preliminary results of the experimental operation of the research prototype of the developed system can serve as confirmation of the effectiveness of the proposed design solutions.
Keywords: regional socio-economic program, linguistic variable, fuzzy production rule, fuzzy logical inference, information and analytical system
Of the industries that consume industrial waste, the construction materials industry is perhaps the largest. The research has determined that the use of industrial waste can cover up to 40% of the construction needs for raw materials. The use of industrial waste reduces the cost of manufacturing construction materials compared to the production of their natural raw materials by up to 30%. The achieved savings in capital investment is approximately 35 ... 50%.
Keywords: industrial waste, effective additives, cost reduction, performance improvement, environmental problem solving
The article deals with the issues related to the design of control devices for technological equipment based on artificial neural networks. The algorithm of the neural network training process based on the Widrow-Hoff method is developed, designed for computer-aided design of artificial neural networks operating in the environment of a microprocessor system or a personal computer. The authors perform a software implementation of the algorithm for training a three-layer neural network using the C# programming language on the platform Microsoft.NET. The program uses a neural network training algorithm with a "teacher". The article shows the interface of interaction of the developed program with the "teacher" (designer of neural networks). An example is given of the development of an artificial neural network that performs the function of a binary number adder. The results of the research can be further used in the development of a computer-aided design system for artificial neural networks, and can also be used in the development of software for microprocessor control systems for technological equipment.
Keywords: artificial neural network, training, algorithm, programming language, neuron bias, adder, input signals, output signals, synaptic connections, neurons
It is indicated in the article that the study of the electron bunching process in the drift space of a transit klystron is an urgent task that allows one to establish general laws applicable to more complex models. In this connection, the behavior of the pre-modulated electron beam in the drift space of the transit klystron has been investigated. A numerical model has been implemented that takes into account the effect of space charge fields and the interaction of charged particles with elements of an electrodynamic system. A series of numerical experiments with different values of the current and initial velocities of electrons, as well as their comparison with theoretical data, have been carried out. As a result of numerical experiments, data were obtained that characterize the dynamics of the electron flux in the drift space of the transit klystron at different values of the initial velocity (0.5 s, 0.9 s) and cathode current (10 mA, 1A, 10A).
Keywords: flyby klystron, mathematical model, numerical simulation, large particle method, particle-particle method, drift space, convection current distribution, electron flow, multithreaded calculations, system of differential equations
This paper considers the vectorization and parallelization of the "particle-particle" method used to take into account interactions between objects in the mathematical modeling of physical processes, using the example of taking into account the space charge when calculating the dynamics of charged particles. Comparison and estimation of time costs are carried out (as a test problem, the expansion of a multicomponent ion beam during one nanosecond with a step of Δt = 10-12 s was considered), taking into account the acceleration due to vectorization and parallelization between processor cores. It is concluded that the results of the work clearly demonstrate that the vectorization of computations can significantly speed up the computation time, and the explicit replacement of scalar operations with vector ones makes it possible to obtain additional speed-up in comparison with the use of automatic optimization of the program code. Key words: parallel computations, "particle-particle" method, vectorization of computations, numerical modeling, Coulomb interactions, dynamics of charged particles, ion beam, program code, equation of motion, mathematical model.
Keywords: parallel computations, particle-particle method, vectorization of computations, numerical simulation, Coulomb interactions, dynamics of charged particles, ion beam, program code, equation of motion, mathematical model
To share and transfer knowledge, they must be presented in an explicit form that is understandable to both humans and computers. The paper proposes an approach to ontological modeling of WHAT-knowledge, which allows representing knowledge simultaneously in two forms: a) in the form of a visual model (ORM2-diagram), understandable to humans, and b) OWL2-ontology, computer understandable. To convert the knowledge representation from one form to another one, it is proposed to use ontological patterns (mapping rules). Currently, there is no software toolkit that allows a) to build an ORM2-diagram and mapping it in the OWL2-ontology, and b) based on OWL2-ontology, build a visual model in the form of an ORM2-diagram. Therefore, we are developing a Protege-plugin, which should provide a) the creation and editing of WHAT-knowledge by building an ORM2-diagram and mapping it in the OWL2-ontology, and b) visualization of WHAT knowledge in the form of an ORM2-diagram, extracting instances of ontological patterns from the OWL2-ontology. The paper provides a functional and structural description of the plugin; examples of its use are given.
Keywords: WHAT-knowledge, explicit knowledge representation, ontological modeling, ontology, visual model, intermediate model, ontological pattern, ORM2-diagram
The decentralized electric power supply zone occupies about 60-70% of the territory of the Russian Federation. Electric power supply here is carried out using electric generator sets with diesel drive engines. In combination with the difficult logistics of fuel and lubricants materials delivery, this leads to a high prime cost of electricity energy generated. In the capacity of a measures to the costs of electricity reduction, renewable energy sources are used, while maintaining diesel generation as a guaranteed supplier of electricity. Renewable energy is characterized by significant stochastic fluctuations. Based on experimental data, the article shows that the daily load curves of small settlements contain a significant stochastic component, which greatly exceeds the seasonal, daily, and technological components in amplitude. The purpose of this work is to substantiate the structure and parameters of a hybrid energy storage device (HESD) for the synthesis of electrical power generation complexes using renewable energy sources. Spectral analysis using the window Fourier transform is used as a tool. It is established that the energy approach to the choosing of HESD components requires N types of electric energy storage devices, which differ in the ratio: the permissible frequency of the charge-discharge cycle to the cost of the component. As a criterion for choosing the structure and parameter values of a hybrid energy storage device, an estimate is proposed for the levelized cost of electricity (LCOE).
Keywords: hybrid energy storage, electrotechnical complex, renewable energy, daily load curve, spectral analysis, Fourier series
The essence of strategic planning is revealed. The importance of strategic planning in construction is proved. The stages of strategic planning are briefly described. The strategic planning procedure is described. The stages of implementing the strategic plan are outlined.
Keywords: strategic planning, organization, construction, resources, financing, development, modeling, expert, implementation, information