Designing function interface in the form of function prototype is an important skill in programming. In this article, we discuss the problems of designing function prototypes in the C programming language. This learning task requires performing 5 different steps. Students can make mistakes at each step. These mistakes can concern misconceptions of function's action, identification of data elements, determining of conceptual-level data types for data elements, data elements' directions, inconvenient naming of function and parameters, and syntax of the C language. Modern solutions for analyzing program code and checking student-written code do not detect all these mistakes in the function-interface design. Existing approaches are based on general solutions for seeking errors in program code so they cannot provide informative feedback about semantic mistakes in designing function interfaces. We propose developing an automatic tutor which should guide students through the process of designing function prototypes step by step, detecting and explaining mistakes at each step and providing hints to help fixing the found mistakes. The tutor should allow natural variability in the function interface. In order to deal with various possible representations of the data passed to and from function, the tutor should work with a formal subject-domain model and a model of the target programming language.

Keywords: automatic tutors, requirements for tutoring systems, introductory programming learning, tasks with complex result, multi-step tasks, online education, mixed education, automatic grading

The article discusses the features of international transport corridors passing through the territory of the countries of the Eurasian Economic Union, analyzes the potential and problems of their development, identifies their prospects for the implementation of large transport and logistics projects. Despite the great attention of scientists from different countries to the issues under study, the issues of the functioning of international transport corridors and their integration into the global transport system require further study.

Keywords: logistics, logistics directions, transport corridors, Eurasian Economic Union, transport routes

Simulation modeling of university scientific activity indicators Based on the developed original algorithms, the results of simulation modeling of the main scientometric indicators of the university and determining its place in the ranking of scientific activity are presented. The influence of the input control parameters of the system on the output integral indicators of the functioning of the university is analyzed, which allows us to propose projects of management solutions to achieve the planned values of indicators of scientific activity.

Keywords: simulation modeling, performance indicators, universities, scientific activity, publication activity, Web of Science, Scopus, RSCI

The analysis of the frequency-controlled drive currently used on the technological equipment of the Volgogradneftemash enterprise is presented. Taking into account the peculiarities of the pumping and ventilation equipment installed at the enterprise, the principles of regulation are determined and the influence of a frequency-controlled drive on the quality of electrical energy is evaluated. The negative influence of the frequency-controlled drive of ventilation and pumping equipment on individual indicators of electricity quality was noted. In order to reduce this influence, an energy-saving device has been proposed for installation. The issues of the possibility of using an energy-saving device at the facility are considered, as well as an analysis of its efficiency during operation from the point of view of improving the quality of electricity in the internal power supply system of the Volgogradneftemash open Joint stock company is carried out. The use of the device is an effective solution, since it leads to high energy efficiency of technological equipment by reducing current surge, suppression of higher harmonics and electromechanical interference.

Keywords: electric drive, ventilation system, frequency-controlled drive, quality of electrical energy, energy saving device

The article discusses the history of the creation of heat generators. the main parameters of work and errors associated with the operation of this equipment. a brief description of such parameters as excess air coefficient, chemical underburning is given. on the example of an industrial enterprise in the city of Volzhsky, the relationship between the main indicators of heat generators and the adjustment of a gas burner is shown.

Keywords: energy saving, natural ventilation, the mechanical central zone ventilation system, the single apartment ventilation system, recovery, a planning solution for a building, energy saving, heat generator, boiler unit, gas burner, efficiency

The article provides an analysis of the possibility of using carbon fiber-based external reinforcement systems to strengthen the load-bearing structures of beam arches along steel beams. The main conclusions based on the results of previously conducted laboratory studies on full-scale samples, as well as the results of the work performed on reference objects are presented. As a result, general conclusions have been drawn regarding the calculation and design, as well as recommendations for further research on the calculation and design of these systems.

Keywords: vaults, prussian vaults, monier arch, external reinforcement, carbon fiber, reinforcement, restoration

The organization of urban space in the current conditions should correspond to modern trends in the development of urbanized systems. This is of particular importance in the case of a production site, as it acts as a source of influence on the residential area. From the point of view of environmental safety, it is customary to locate such sources of exposure far from the residential environment, minimizing the negative impact and production risks. At the same time, the need for transport accessibility of the enterprise to ensure supply chains and perform a city-forming function leads to the actual placement of production areas as close as possible to the residential area. The negative impact on the environment in such cases should be minimized or absent through the use of modern technical and technological advances. Ensuring a positive perception of the production complex by citizens and employees is possible by improving the quality of territory organization using the basic principles of architectural and landscape organization. An open-type production area in this case will allow creating the image of a safe enterprise both from the point of view of the environment and the urban space. The article discusses the basic principles of the formation of a favorable architectural and landscape appearance of the production area, including transport accessibility; organization of the territory; the use of various methods of greening and small architectural forms; combination of color and shape; special arrangement of functional buildings and structures. The use of the proposed principles in practice ensures the formation of a new qualitative level of the production space and the urbanized system as a whole.

Keywords: production territory, architectural and landscape organization, principle of territory organization

The article presents an overview of the work on modeling the behavior of a double electric layer in membranes under influences of various nature, including the example of various surface phenomena (adsorption, surfactants, adhesion, wedging pressure, electroosmosis, etc.). It was noted that the size and distribution of the charge over the surface near which it is formed has an effect on the structure of the DES; to obtain the potential distribution, it is necessary to know the structure of the membrane-electrolyte solution interface; it is intermediate to be able to calculate the charge distribution, and, accordingly, to calculate the potential distribution itself. It was pointed out that when choosing a mathematical interpretation of the process, the Poisson equation is often used, taking into account the self-consistent field, or the Navier-Stokes equations are solved together with the Nernst-Planck equation and the electroneutrality condition; the Gui-Chapman model is used to describe processes with low accuracy by molecular dynamics methods, supplemented by the ion adsorption condition according to the Langmuir isotherm; when modeling the electrolyte current, the description of the surface current of ions is used, taking into account the viscous properties of the medium.

Keywords: double electric layer, zeta potential, membrane, primembrane layer, spatial charge density, Navier-Stokes equation, surface current, Poisson equation, capacitor, fluid flow potential

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