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
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
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
When building complex technical systems, as a rule, the resources of an existing system are used as a basis, which may be redundant due to the lack of a clear definition of what the system is needed for. This necessitates the determination of the system intended purpose, the selection of elements for its construction and management in the process of its operation, aimed at achieving the intended purpose and optimizing the resource support used to build the system. The paper proposes an approach to building a system based on the development of its functioning profile, which characterizes the achievement of its intended purpose, modeling the process of a complex technical system functioning and evaluating the effectiveness of the profile. The use of the proposed methodology will allow, at the stage of building a complex system, to improve the quality and efficiency of designing a complex technical system by taking into account the functional needs of the system, as well as determining the amount of resources required to fulfill them.
Keywords: profile, complex technical system, criticality, system design, system construction, control process automation, functions, tasks, resource
To analyze such significant indicator of the locomotive industry as the value of import customs payments, the dependence of the volume of import customs payments on weight, cost, weighted average rate and dollar exchange rate is examined. Mathematical modeling was carried out on the basis of monthly data during the period from 2019 up to 2021 of the volumes of customs payments and their parameters of the Group 86 of the Customs nomenclature of EAEU FEA "Railway locomotives or tram motor cars, rolling stock and their parts; track equipment and devices for railways or tram tracks and their parts; mechanical (including electromechanical) signaling equipment of all types". The interrelations of these variables are represented by a system of simultaneous structural equations. The import substitution trend developing in Russia implies strengthening the development of national industries and, accordingly, pursuing a customs policy that implies support for domestic producers and reduction of import supplies. Thus, it is relevant to determine the impact of various factors on the amount of customs duties levied by the customs authorities on foreign economic activity (FEA) participants in operations involving the import of spare parts and other goods for the locomotive building industry to make the right strategic decisions concerning customs restrictions on imports of goods of this industry.
Keywords: locomotive building industry, mathematical modeling, linear multiple regression, multicollinearity, system of simultaneous equations, identification, structural form of the model, reduced form of the model
The article discusses approaches to solving natural language processing problems such as extracting key concepts or terms, as well as semantic relationships between them to build data-driven IT solutions. The subject of the work is relevant due to the constant growth of volumes of low-structured and unstructured digital text. The extracted information can be used to improve numerous processes: automatic tagging, optimization of content search, construction of word clouds and navigation sections; furthermore, to create draft versions of dictionaries, thesauri, and even bases for expert systems.
Keywords: natural language processing, term, lemma, semantical relationship, statistical processing, machine learning, word2vec
The purpose of this article is to conduct a comparative analysis of methods for assessing the technical condition of buildings and structures. The article considers various approaches to assessing the technical condition of buildings and structures, reviews and compares methods, identifies key differences between the foreign approach and the domestic one. The review of methods for assessing the technical condition presented in the article allows us to conclude that a variety of methods can create certain difficulties when choosing and using them. The analysis of domestic and foreign experience has shown that the most popular today are systems for monitoring the technical condition of buildings and structures, involving a set of measures using modern assessment, modeling and forecasting technologies that allow obtaining operational information about the technical condition of buildings.
Keywords: physical wear, operation, technical condition assessment, monitoring, operational qualities, instrumental examination, expert-normative method, cost compensation method
The article presents a study aimed at developing methods and algorithms for analyzing spatial data for diagnosing the state of geosystems. It is shown that the combination of machine learning models into an ensemble makes it possible to increase the stability of the analyzing system: the accuracy of decisions made by the ensemble tends to tend to the accuracy of the most efficient monoclassifier of the system. The calculation and consolidation of territorial descriptors at the same time make it possible to reduce the dimensionality of the analyzed data, facilitate the allowable capacity of the machine learning model, increase its resistance to overfitting, and prevent a significant decrease in the classification accuracy within the framework of a specific problem being solved.
Keywords: metageosystems, spatial data, test sites, territorial descriptors, ensembles
The article presents a methodology for multivariate analysis of intercomponent relationships in geosystems, implemented on the basis of two strategies: the use of numerical, including statistical, methods to assess the degree of influence of various parameters on the state of the geosystem model and the use of simulation to assess the dynamic properties of geosystems and solve the problem of spatial forecasting . The algorithm for assessing the importance of geosystemic parameters makes it possible to evaluate the impact of various parameters on the target indicator in the framework of solving design problems. The concept of building simulation systems for solving the problem of assessing the dynamics and forecasting the development of metageosystems is characterized.
Keywords: metageosystems, spatial data, modeling, intercomponent connections
In modern conditions, the healthcare system is going through a stage of active implementation of information and analytical tools. In the regions contaminated with radionuclides as a result of the accident at the Chernobyl nuclear power plant, activities for the prevention, detection and management of cases of thyroid diseases are of particular importance. Modern formalized methods of analysis, such as methods for searching for association rules, clustering using self-organizing maps, have sufficient functionality and effectiveness to be introduced as sources of new knowledge about the signs of thyroid diseases. In this paper, the authors consider the stages and results of developing a software package for information and analytical support for the process of examining the thyroid gland using ultrasound.
Keywords: diversification of management, production diversification, financial and economic purposes of a diversification, technological purposes of ensuring flexibility of production
Global Positioning System (GPS) data acquisition devices have proven to be useful tools for collecting real-world motion data. The data collected by these devices provide valuable information when studying the vehicle movement parameters. For vehicle modeling, this data is invaluable for analyzing fuel consumption and vehicle performance. The study presents a methodology for developing the driving cycle of special cars, during which the speed profile of a particular type of vehicle is studied, loaded and processed, and noisy data is filtered for the purity of the experiment. The test data for severe operating conditions are analyzed. A city driving cycle has been developed for a special truck concrete mixer truck in the conditions of the city of Tyumen. Estimated fuel economy of the specified vehicle is estimated.
Keywords: driving cycle, fuel efficiency of concrete mixer truck, noisy data, data filtering, GLONASS/GPS
The article presents an approach to the development of a case-based decision support system for assessing the safety of a section of a city's transport system. To store the database of precedents, it is proposed to use an OWL ontology. The use of the ontological approach allows a more accurate interpretation of the subject area, and over time will expand and supplement information about the precedent. The precedent structure is defined. The ontology architecture is given: classes, properties and instances. An example of filling the ontology with precedents is given, using the example of the city of Volgograd. Measure of proximity to compare precedents is proposed. The procedure for adding new precedents to the knowledge base is considered. With the help of the developed decision support system, it is possible to assess the safety of both individual road sections and the entire transport infrastructure of the city.
Keywords: ontology, reasoning by precedents, transport, transport security
The article presents an analysis of existing methods for determining the stiffness parameters of bent reinforced concrete elements reinforced with external reinforcement based on carbon fibers. The results of comparing the results of the determination of stiffness by practical methods and laboratory tests are presented. As a result, general conclusions and recommendations were made for further research of this issue, as well as the general parameters of the carbon fiber-based reinforcement system needed to be taken into account.
Keywords: external reinforcement, carbon fiber, reinforcement, restoration
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