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  • Construction and evaluation of the effectiveness of a decision tree model for predicting student performance

    This work solves the problem of increasing the effectiveness of educational activities by predicting student performance based on external and internal factors. To solve this problem, a model for predicting student performance was built using the Python programming language. The initial data for building the decision tree model was taken from the UCI Machine Learning Repository platform and pre-processed using the Deductor Studio Academic analytical platform. The results of the model are presented and a study was conducted to evaluate the effectiveness of predicting student performance.

    Keywords: forecasting, decision tree, student performance, influence of factors, effectiveness assessment

  • Algorithm of nonparametric estimation of transition probability distribution density for Markov model of university staff dynamics

    The paper deals with the construction of an algorithm for nonparametric estimation of the transition probability distribution density for the Markov model of the dynamics of the number of university employees. The problem of reconstruction of transition probability distribution density on a retrospective sample of small volume is solved. The result of the solution is the transition probability matrix, the elements of which are random variables with distribution laws obtained from retrospective data. A distinctive feature of the algorithm is the simultaneous consideration of regional and functional constraints on the values of transition probabilities. The convergence of the algorithm has been experimentally confirmed.

    Keywords: probability density, nonparametric estimation, Markov model, simulation modeling, university staff movement, publication activity

  • Simulation of the design activity diversification of innovative enterprise

    The article presents the results of a survey of two industrial buildings, conclusions about their emergency technical condition and the inexpediency of restoration. Modern methods of demolition and dismantling of buildings in the cramped conditions of the existing urban development are analyzed. The main technologies of recycling dismantling and disposal of construction waste generated during the dismantling of buildings are considered: "smart demolition" and the technology of piecemeal disassembly of buildings with the reuse of materials, products and structures. Comparing the two methods of recycling dismantling for application to the objects under consideration, it is concluded that the first method of "smart demolition" implies the destruction of all building structures, while the second is more rational in terms of resource conservation and economic efficiency by reuse of serviceable structures. The technology of piecemeal disassembly of buildings with the reuse of structures requires the development of regulatory, organizational and marketing measures.

    Keywords: building inspection, demolition, dismantling, dismantling methods, smart demolition, recycling dismantling, reuse of structures

  • Preservation of greenery during construction

    The issues of preserving existing green spaces and other elements of the natural landscape during new construction are considered. Methods for preserving perennial plantings throughout the entire course of construction are proposed. If it is impossible to save the tree at the construction site, a method of transplanting it to another place is proposed. It is proposed at the stage of design and survey work to identify healthy trees that do not grow on the site allocated for a building (structure) under construction. Then solve the problem of locating the object on the ground in such a way as to preserve healthy perennial trees as much as possible. To do this, it is necessary to carry out the removal of the object to the area, moving it as far as possible from healthy trees. The distance required to protect the tree from external influences during work is equal to the projection of the crown on the ground plus 1.5 m. At this distance, it is recommended to make stationary fences for each tree. A tree transplantation scheme and a method for calculating its weight for the selection of equipment for digging and transportation have been developed.

    Keywords: landscaping, construction, tree, tree transplanting, asphalting

  • Application of machine learning methods for the analysis of personality psychotypes

    This article discusses the solution of the problem of monitoring contact information in a social network and determining the personality psychotype based on it. Most of the material proposed by the developers works with English-language texts to determine the emotional coloring, their classification and, to a lesser extent, clustering. The approach proposed in the article is based on the use of the K-means method to solve the clustering problem of Russian-language texts and subsequent comparison with the results of working with the same data of an already trained model. During the work, was developed an effective method of parsing for collecting data. A proprietary data set has been collected and its processing and detailed analysis have been carried out. The result of the study allows us to make a primary assumption about what kind of psychotype a particular person has. It is quite difficult to determine the accuracy of the results of the task, since there is no predefined correct answer in machine learning without a teacher, and determining the psychotype is a difficult task from the point of view of psychology. All program code is written in the Python programming language.

    Keywords: clustering, psychotype, social network, sanguine, phlegmatic, choleric, melancholic

  • Some aspects of mathematical models of crack resistance of reinforced concrete rod elements

    The assumptions of mathematical models for calculating the crack resistance of reinforced concrete structures are considered. For each of them, an analysis was carried out to determine whether they correspond to reality throughout the entire life cycle of the structure: from the hardening of the concrete mix to destruction. Based on the results of the analysis, it was proposed to use only one single calculation at the level of standards to assess the crack resistance of structures - according to the crack opening width, acrc. So, for example, at a certain value of acrc, the structure will still remain airtight (the cracks will be non-through), and if this value is exceeded, it will not. At the same time, the calculations already available in the norms for limiting permeability and the safety of reinforcement will still remain in demand. At the junction of the theory of damage accumulation and nonlinear fracture mechanics, a compressed algorithm is proposed for possibly taking into account the influence of cracks at all scale levels of the concrete structure, the key for which is the normalization of the statistical parameters of the distribution of discontinuities by diameters, lengths, openings, depths, directions, distances between discontinuities, etc.

    Keywords: reinforced concrete, crack resistance, cracking moment, crack width, plasticity coefficient, damageability, non-linear fracture mechanics

  • Automation of the process of selecting the optimal parameters of excavator hydraulic shears for cutting metal structures

    The article discusses a mathematical model of an excavator's hydraulic shears, which describes the functional dependencies of their main parameters based on regression statistics. An algorithm for the process of selecting optimal parameters for hydraulic shears used to destroy metal structures during the dismantling process is presented, and a description of the developed software application that automates the process of selecting these parameters is given. The application described in the article will reduce the time required for the design stage of excavator attachments.

    Keywords: attachments, hydraulic shears, dismantling, metal cutting, design, mathematical model, automation, selection of parameters, algorithm, program

  • S.A. Danini's contribution to the design and construction of the Red Cross Sisters of Mercy Community building in Tsarskoye Selo

    At the beginning of 1908, the Tsarskoye Selo Community of the Sisters of Mercy of the Red Cross was organized in the city, which was allocated a plot for the construction of a building for an outpatient clinic and a dormitory of the sisters of mercy with a church. The development of the project and supervision of the construction was carried out by architect S.A. Danini. Construction of the building was started in 1912 and completed in October 1914. The internal load-bearing structures of the building were made of monolithic reinforced concrete, central water heating and ventilation system were used. Building survey in 2017-2019 it has shown that it is possible to reconstruct it for a day-stay boarding house for disabled children.

    Keywords: Tsarskoye Selo, S.A. Danini, Community of the Sisters of Mercy of the Red Cross, architectural planning solutions, reinforced concrete structures, building surveys, church in honor of the Icon of the Mother of God of All Sorrowing Joy

  • Computer modeling of the number of flowing and non-flowing cultures of microorganisms

    The article is devoted to the development of a computer program with the help of which it is possible to simulate the number of flowing and non-flowing cultures of microorganisms for educational purposes. The Mono model is taken as the basic model of biomass growth. The apparatus of ordinary differential equations is used for the mathematical description of cell populations. As a result, the structure and functionality of the electronic learning module with its subsequent implementation in Python has been developed. As a result, the laboratory work "Modeling of flowing and non-flowing cultures of microorganisms" was developed, in the form of a computer program, performed within the framework of mastering the discipline "Biophysics" and consisting in studying the basic principles and methods of modeling the processes of development of microorganisms in flowing and non-flowing cultures. The developed program is implemented in the educational process.

    Keywords: computer program, cell population, biophysics, microorganisms, computer modeling, Mono model, Python, biomass, flow conditions, non-flow conditions, system of equations

  • Method for constructing a profile of a complex technical system functioning

    In the modern world, the number of different complex technical systems is only increasing every year, and any system incorporates or uses a third-party communication system. Disruption of the communication system and its elements functioning can lead to a situation where a complex technical system cannot realize its functions. It is required to ensure the guaranteed functioning of the communication system and its elements. One of the ways to ensure the stable operation of complex technical systems is the implementation of the control function by the control system, while in the process of system operation it is necessary to take into account not the characteristics and parameters of individual elements that describe their operation, but the ability of the system to perform tasks and functions. The paper proposes an approach to describing the functioning of a communication system through the formation of the system functioning profile, which is a set of matrices, which is used in the control system.

    Keywords: functional stability, criticality, communication system, control system, complex technical system, functions, tasks, profile, regulations

  • Using Genetic Algorithms to Increase the Learning Rate of Neural Networks

    Investigation of ways to accelerate the training of neural networks using genetic algorithms and the study of the dependence of the speed of genetic algorithms on the mutation rate. In this study, a program was implemented on the Unity graphics platform using genetic algorithms and mutations to determine their optimal coefficient. The experiment showed that the learning rate really depends on the mutation rate, and the highest learning rate was obtained at 5-7,5%.

    Keywords: machine learning, deep learning, genetic algorithm, optimization, neural network, artificial neuron, mutation, artificial intelligence, non-player character, optimization

  • Assessment of a contamination level in the landfill's soil-like fraction within the boundaries of Volgograd's northern industrial hub

    The article presents the study results of a soil-like fraction contamination at a landfill located on the territory of the Traktorozavodsky district of Volgograd with heavy metals. The soil-like fraction's pollution level was assessed using a cumulative chemical pollution index (Zc) and its modifications. It was determined that the contamination levels with heavy metals are dependent on a used cumulative chemical pollution index modification. The use of the average geometric values of a cumulative chemical pollution index (Zc) is preferred for a pollution assessment of a soil-like fraction. Because the pollution level of a studied soil-like fraction was assessed as hazardous, its use as a recultivation material can only be permitted after a detoxification.The main pollutants in the soil-like fraction are cadmium, copper, and nickel.

    Keywords: landfills, soil-like fraction, heavy metals, pollution level

  • Assumptions of mathematical models of crack resistance of reinforced concrete rod elements

    The assumptions of mathematical models for calculating the crack resistance of reinforced concrete structures are considered. For each of them, an analysis was carried out to determine whether they correspond to reality throughout the entire life cycle of the structure: from the hardening of the concrete mix to destruction. Based on the results of the analysis, it was proposed to use only one single calculation at the level of standards to assess the crack resistance of structures - according to the crack opening width, acrc. So, for example, at a certain value of acrc, the structure will still remain airtight (the cracks will be non-through), and if this value is exceeded, it will not. At the same time, the calculations already available in the norms for limiting permeability and the safety of reinforcement will still remain in demand. At the junction of the theory of damage accumulation and nonlinear fracture mechanics, a compressed algorithm is proposed for possibly taking into account the influence of cracks at all scale levels of the concrete structure, the key for which is the normalization of the statistical parameters of the distribution of discontinuities by diameters, lengths, openings, depths, directions, distances between discontinuities, etc.

    Keywords: reinforced concrete, crack resistance, cracking moment, crack width, plasticity coefficient, damageability, non-linear fracture mechanics

  • Designing requirements to a tutoring system for teaching construction of English phrases with the correct order of adjectives

    English is an analytical language, so in English, the word order is important for understanding sentences and phrases. Practicing construpcting noun phrases with the correct order of adjective requires constant practice with feedback. As teachers' time for verifying assignments is limited, we propose to use a tutoring system, which can generate step-by-step feedback. It will help students develop the skill of arranging adjectives in the correct order.

    Keywords: tutoring system, ontological modeling, natural language processing, English, adjective order, hypernyms, automated verification of the learners' answers

  • Urban environment as an ecosystem of modern society

    The urban environment is formed by anthropogenic and natural factors. The authors proposes consideration of the urban environment as a complex ecosystem, determined by urban planning elements. The quality of the urban environment determines the degree of favorableness in this environment and compliance with modern requirements and living conditions. The essential factors that determine the urban environment – technical, architectural, planning, engineering. Technical factors form the frame of the urban environment (constructive solutions). Architectural means determine the visual perception of the urban environment. Planning factors include methods of planning and development of the territory. Engineering factors ensure the development of engineering infrastructure. In addition, technological factors ensure the use of new smart technologies. Technogenic factors create negative external effects of the urban environment. The main condition for considering the urban environment as an ecosystem is the compliance of all urban planning decisions with environmental standards. The use of an integrated approach when changing the design solution of the urban environment makes it possible to rationally and effectively prevent and identify negative impacts.

    Keywords: urban environment, environmental factor, ecosystem, integrated system, environmental standard