When evaluating student work, the analysis of written assignments, particularly the analysis of source code, becomes particularly relevant. This article discusses an approach for evaluating the dynamics of feature changes in students' source code. Various metrics of source code are analyzed and key metrics are identified, including quantitative metrics, program control flow complexity metrics, and the TIOBE quality indicator. A set of text data containing program source codes from a website dedicated to practical programming, was used to determine threshold values for each metric and categorize them. The obtained results were used to conduct an analysis of students' source code using a developed service that allows for the evaluation of work based on key features, the observation of dynamics in code indicators, and the understanding of a student's position within the group based on the obtained values.
Keywords: machine learning, text data analysis, program code analysis, digital footprint, data visualization
The paper provides a brief overview of publications on the application of mathematical modeling methods in the study of the patterns of functioning of hydroelectric power plants (HPPs). In particular, the following are considered: mathematical models of the total minimum water consumption for a cascade hydropower system in China; a mathematical model of hydropower plants; a mathematical model of two small hydroelectric power plants operating in tandem; accurate modeling of hydraulic transient characteristics in a complex drainage system. The task of filling in the gaps in the data concerning the operation of hydroelectric power plants is formulated. The approach to its solution is proposed to be based on the use of the method described in previous publications by one of the authors and based on the use of regression analysis apparatus. The specific task of filling in data gaps for a hydroelectric unit of one of the Siberian hydroelectric power plants has been solved. The following factors are used: active and reactive power of the electric generator, voltage, current and temperature of the stator iron, rotor current, air cooler hot air temperature.
Keywords: hydroelectric power plant, electric generator, data gaps, predictive analytics, regression model, adequacy criteria
Digital twins of railway stations are necessary for planning work and taking the most effective management actions. An important factor is the compliance of the planned time costs with the actual ones. One of the tasks that are difficult to formalize at railway stations is the process of holding the rolling stock. This is due to the fact that the holding time depends on the human factor and the holding rolling stock. To create an automated station controlled by a digital twin, it is necessary to develop an automated holding system. One of the tasks in developing such a system is the problem of device location. This problem can be formulated as follows: it is necessary to place the minimum allowable number of holding devices in the controlled area in such a way that reliable holding is provided for any configuration of the rolling stock. As a tool for solving this problem, the most effective will be the use of methods of genetic algorithms. In this article, the authors consider the relevance of this study and the relevance of automating the holding of rolling stock.
Keywords: digital railway station, automation, brake shoes, UTS-380, DUZS, traffic safety.
For prototyping virtual resources, there are modern UI/UX development applications that have the means to build highly productive interaction algorithms, for example, Figma or its promising new competitor Pixso. These programs support the joint redating of projects, and also allow planning and discussion of ideas and stages of work here, in the environment. The correctly chosen method of interaction leads to a multiple increase in productivity. One of the recognized approaches to project planning and management is the Agile design methodology.
Keywords: team, layout, prototype, website, methodology, formal language, brainstorming, frame, project, interface, plugin, editor
Nowadays, the System on Chip (SoC) industry is rapidly developing. One of the objectives of SoC developers is to provide the most efficient communication between computational units. One of the possible solutions is using Networks on Chip (NoC) of various topologies with different routing algorithms. In this paper, a configurable test environment designed for cycle-accurate NoC simulation as part of a SoC, used to provide statistics about network behavior during test process, is presented. The environment is designed to evaluate NoC performance as part of a specific SoC at the development stage, when there is a full or partial RTL description of the system. The environment configuration options, its application area, general scheme and calculated NoC performance characteristics are considered. As a conclusion, an example of using the environment to evaluate the performance of a specific NoC is described in detail.
Keywords: network on chip, system on chip, performance evaluation, verification
The design of energy-efficient buildings is based on the analysis of the external climatic effects on buildings for various purposes, the parameters of the air environment inside which are well defined. Climate systems of buildings should neutralize the negative impact of the external environment, in particular wind exposure. It determines both the temperature regime of the room and the purity of the air inside them. The complexity of both theoretical research and the organization of field experiments or blowing models of buildings in a wind tunnel makes it necessary to resort to mathematical modeling of the wind impact on the school building based on the StarCCm+ program. Velocity fields were obtained for different directions of wind load, the excess heat loss of the building in certain directions was determined. The possibility of conducting such studies in a wider range of initial and boundary conditions is shown.
Keywords: aeration of residential buildings, mathematical modeling
The paper presents the properties and nomenclature of products made of ceramic fiber used for insulating lining in steam reforming furnaces. On the example of the lining of the radiant chamber, the technology of mounting ceramic blankets on anchor studs, which is currently used in the construction and repair of reforming furnaces, is considered. The shortcomings of the existing technology are noted. These include the complexity of the process, the complexity of installation control and the high probability of uneven thermal conductivity of the lining surface due to hidden defects, as well as the spraying of ceramic fiber particles in the air that cause diseases. The nomenclature and technology of installation of insulating lining with ceramic blocks along guide tubes with subsequent resistance welding with the camera body is proposed. The technology will reduce the repair time, improve the thermal conductivity of the camera, reduce the risk of diseases.
Keywords: gas reforming, radiant chamber, insulation lining, ceramic fiber, thermal conductivity of the furnace
The article presents the development trends of prefabricated-monolithic frame systems (PMFS) in the countries of East Asia, mainly China and Japan. The presented PMFS have different features in comparison with technologies used in European countries and the USA, which are dictated by several factors: geographical features, high population density and uneven distribution in the territory, the continuing need accelerate of construction rates. Based on the analysis results of open information sources there were singled out 4 bearing framework formation systems , actively used by the large construction companies. The presented systems combine structural and technological solutions of modular, hybrid and prefabricated-monolithic construction. The use of bearing structures joints which makes it possible to erect buildings with a high class seismic resistance at a significant number of storeys is considered in detail. In the conclusion, the main features of the Asian PMFS, which have no analogues among the other systems, have been summarized. The results obtained can be used as basis for further larger and more effective development of the civil prefabricated-monolithic buildings.
Keywords: civil construction, prefabricated-monolithic construction, modular, hybrid, structural parameters, load-bearing structures, analysis, comparison, advantages, disadvantages
The results of the automated evaluation of the dynamic quality of grinding machines in the process monitoring system are presented. The transfer function of the dynamic system is analytically obtained, a formula for the frequency function is derived from it, on the basis of which models of vibration spectra are constructed, in which frequencies are present that are adequate to the real vibro-acoustic vibrations of the dynamic system of the machine when processing rings. For experimental evaluation of the dynamic quality of machine tools, integral estimates of the low-frequency components of the vibration spectrum are used, characterizing the relationship between the quality of processing bearing rings and the dynamic quality of machine tools.
Keywords: dynamic quality of the grinding machine, vibroacoustic vibrations, bearing rings, processing quality, monitoring system
Reducing the consumption of heat resources in construction and housing and communal services is one of the key tasks solved by design engineers. The increase in the thermal protection of buildings is determined by regulatory documents, but construction customers often require it to be strengthened without any feasibility study. The objective of the study is to develop a graphical-analytical model, the analysis of which allows you to choose the most optimal combination of heat resistances of the coating (walls) and translucent structures of a particular building object.
Keywords: energy-saving project, thermal protection of buildings, "indifference" curves, the method of the fastest descent
The issues of ensuring the reliable operation of bearing production on the basis of the organization of the process monitoring system (SMTP), based on the introduction of effective automated control and diagnostics of technological equipment, including processing modes and technical condition, active control of product quality in the manufacturing process, output characteristics of rings processed by the eddy current method, as well as making decisions on timely maintenance of equipment. The results of the inspection are stored in a report file generated in the eddy current device computer: information about each checked part is stored: the time of inspection, the type of part, the surface to be monitored, the number of the machine on which the part was processed. The results of eddy current control serve as the basis for monitoring the dynamic characteristics of the equipment by vibroacoustic vibrations. Based on the results of the control within the framework of the SMTP, a decision is made on the quality management of processing. The introduction of SMTP provided a significant reduction in ring defects in terms of grinding quality up to 2-3 % and increased operational reliability of bearings.
Keywords: grinding process monitoring, bearing rings, dynamic machine quality, active control, eddy current control, ring quality
Conducting land management activities is one of the most complex processes, as it includes a large complex of works aimed at studying the state of land resources, their distribution and the organization of the territory as a whole. A special place in land management is given to geodetic works, which are characterized by sufficient complexity of their implementation. In this regard, there are many questions concerning the organization and implementation of this type of work. This article will discuss the main stages and features of geodetic works in the implementation of land management measures.
Keywords: geodetic works, land management measures, topographic and cartographic materials, topographic and geodetic surveys, cameral works, geodetic basis, survey networks, technical specification, cadastral plan, rational use of land resources
Reducing energy consumption in the design, installation and operation of engineering networks is implemented in the process of implementing investment construction projects. An energy service contract, like any economic agreement, requires a feasibility study. When strengthening the thermal protection of a building, it is necessary to determine both the design of the fences and translucent structures, and the payback period of the investment. The objective of the research is to develop and analyze a mathematical model of heat losses depending on the characteristics of the resistance to heat transfer of walls, windows and balcony doors. Classical dependencies do not allow applying standard mathematical analysis procedures. It is proposed to use a power function that assumes the availability of differentiation. The paper substantiates the form of such a function and provides an extended analysis of the effect of changes in the resistance to heat transfer of building structures on the transmission heat losses of a building, which allows arguing for the adoption of optimal technical and economic decisions.
Keywords: energy-saving construction project, thermal protection of buildings, indifference curves, mathematical model of heat loss
The purpose of our work was to search for possible options for the secondary use of destroyed brick buildings and structures. We conducted tests to verify the strength characteristics of bricks taken from the sites of reconstruction and complete demolition of buildings and structures. In the course of which, conclusions were drawn about the possibilities of further use of brick scrap from different places of demolition of building structures.
Keywords: demolition, scrap, building, structure, brick, recycling, testing, strength, recycling, iron concrete
The possibilities of using volcanic tuff as an additive in pressed cement-mineral composites intended for road construction are studied. The influence of low-modulus mineral additives of trepel, granulated blast furnace slag and volcanic tuff on the physical and mechanical properties of hardened composites is studied. The rational compositions of the molding masses of the optimal structure of cement-mineral composites providing the improvement of physical and mechanical properties are determined.
Keywords: small-piece pressed products, hard pressing, cement-mineral composites, paving slabs, screenings, volcanic tuff, trepel, granulated blast furnace slag, structure-forming additive, decaying strength