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  • "Smart Grids" of Volgograd heat supply systems

    This arcticle are devoted to the modernization of housing and communal system based on the technology of "Smart Grids". The methology of developing an assessment of the effectiveness of the project of the modernization of housing and communal services facilities using the technology of "Smart Grids" is given. It from the publication that the use of "Smart Grids" technology provides energy and economic efficiency in the development of the city's energy system

    Keywords: Smart grids, "Smart City", centralized heat supply systems, individual heat supply, evaluation of the economic modernization project, key performance indicators

  • Control and measuring system for dynamic measurement of cargo dimensions

    The system for measuring cargo dimensions is designed for streaming measurement of cargo dimensions, which can be luggage at airports and transshipment bases, various parcels, as well as commercial cargo. The authors of the article developed a structural and functional diagram of a control and measuring system for dynamic measurement of cargo dimensions, and also considered the principles of its operation.

    Keywords: control and measuring system, measurements, cargo dimensions, luggage, automated systems

  • Management of the educational process in higher education with a mixed and distance learning format

    The work updates a strategic approach to maintaining the quality of student performance. In the article "Big Data" is presented as an approach to organizing the data obtained during the educational process. Mining analysis as a Big Data analysis tool. The authors also considered approaches to improving the effectiveness of learning, which allow predicting student performance. Blended learning, as an integration into the educational process, the best opportunities for online and distance learning, provided for the subsequent collection of Big Data for analysis. The application of data mining methods for the development of models for predicting the behavior and academic performance of students is considered. The authors propose student modeling as a key concept in data mining in education, which refers to the qualitative representation of student behavior. Algorithms for data mining are described, classification and clustering are presented as the most common tasks. The CART decision tree algorithm is presented as one of the effective data mining methods needed to predict student performance based on online activity that is stored in the Moodle LMS log file. Finally, it was concluded that the personal contact of an experienced teacher with a student in the educational process can not be replaced by the tools provided by Moodle and similar systems, but due to the growing threats caused by the pandemic, the relevance of distance education is becoming increasingly important.

    Keywords: student performance quality, big data, data mining, student modeling, CART decision tree algorithm, Moodle LMS, distance education

  • Strengthening of wooden structures with carbon fiber during the reconstruction of objects on the example of the historical and architectural museum-reserve "Kizhi"

    One of the most relevant areas in construction is the improvement of methods of reconstruction of buildings and structures. An innovative solution to this issue is considered to be the reinforcement of construction objects with composite materials, in particular, the reinforcement of structures made of natural anisotropic material - wood.

    Keywords: wood, carbon fiber, composite, materials, reinforcement, structures, reconstruction, restoration, labor intensity, cost, strength, deformability.

  • Using the mean distance criterion to identify novelty in the data

    The article discusses the features of identifying novelty in data, as well as general methods for identifying it. Since the absence of noise in the training information is a determining factor for building high-quality classifiers on it in supervised machine learning, such a practically important special case of the search for novelty is considered, when it is determined in separate classes of training data after all outliers have been eliminated in these data. For greater definiteness, when searching for novelty, its geometric interpretation in the space of object feature values.

    Keywords: data, classifier, outliers, novelty, novelty detection, geometric approach, statistical criterion

  • Technological and economic aspects of the development of the light concrete industry for structural purposes

    Concrete has unique properties that allow it to occupy a leading position in the market of building materials. General-purpose structural concrete is used for the construction of buildings and structures that can provide sufficient strength and elasticity for load-bearing and enclosing structures. Concrete production technologies are in constant development, inextricably linked with the solution of the most important task – reducing the mass of building materials, and, as a result, reducing the material consumption of construction

    Keywords: capital construction, structural concrete, heavy concrete, light structural concrete, resource saving, economic feasibility of using light concrete

  • Application of mathematical model of logistic regression for malignant skin lesions recognition on digital skin images

    The aim of this study was to analyze the possibility of using a mathematical model of logistic regression for the recognition of malignant neoplasms on digital images of the skin. The study used a database containing 6594 digital skin images. At the first stage of the study, digital skin images were segmented to isolate the object under study, in which morphometric and color characteristics corresponding to the parameters of the classical ABCD system were determined. At the second stage, the characteristics were used in the classification into malignant and benign neoplasms using logistic regression. When classifying images, the highest value of the accuracy indicator (67.9 [66.9; 68.8]%) was obtained during classification using logistic regression, built on the basis of the reverse Wald stepwise method. Thus, the logistic regression built on the basis of the reverse stepwise Wald method can be applied in the classification of malignant neoplasms on digital images of the skin, but further research and determination of the optimal parameters are required.

    Keywords: mathematical model, digital skin images, logistic regression, image classification, skin cancer

  • Improvement of earth works when constructing multi-storied operated parts of building under the conditions of dense urban development

    The article proposes a special device to transport earth when building an underground part by the «top-down» and «top and down» technique. The developed device is fully electrically powered. The proposed technology enables to completely exclude nonproductive movements of excavating and transportation devices to relocate the earth from the working site to the dumping site onto trucks above ground. The device is adapted to work as part of the production line when realizing the “top-down” and «top and down» technology. To exclude load lifting mechanisms for lifting and dumping of the earth onto the trucks above ground, it is proposed to use two lifting rails with hoisting equipment fixed on a metal frame.

    Keywords: “top and down” technology, earth works, excavation works, subsurface part of a building, earth movement, tier of a subsurface part of a building

  • Experimental implementation of hybrid cloud service based on the sharing economy principles

    The article discusses the experimental implementation of a cloud data center based on the principles of sharing economy. The research presents an algorithm and implementation of resource management for shared consumers. The article demonstrates a qualitative assessment of the system performance and basic performance tests of web applications deployed according to the proposed model.

    Keywords: cloud technologies, web application, consumer economy, virtua

  • Application of tensor methodology for the design of mathematical models of electromagnetic drives

    When creating a model of a nonlinear electrical system based on differential equations, it is important to keep in mind that ordinary differentiation does not give an adequate mathematical idea of ​​the nonlinear physical processes taking place. Even in the simplest case of a conductor with a current, the construction of an adequate model is only possible if the tensor approach is applied. From this point of view, any electrical system is an object of tensor methodology. A typical example of a non-linear electrical system is an AC electromagnetic drive. The nonlinear nature of the processes in such devices is due to a number of reasons. The main reasons are: current displacement in the winding of the AC electromagnetic drive and saturation of the steel of the magnetic circuit in the process of magnetization. Both phenomena admit tensor description, which is confirmed by the research presented in the article.

    Keywords: dynamic characteristic of magnetization, electromagnet, mathematical model, tensor methodology

  • Correction of training samples taking into account errors in measuring the characteristics of objects when constructing classifiers according to the methodology of teaching with a teacher

    Noise in training samples, the main part of which is made up of outliers and novelty, is considered. The analysis of the main causes of outliers in training samples is given. The essence of the main existing approaches to determining outliers in training samples is considered. Based on the use of the nearest neighbors method, a modified method for comparing generalized distances from objects to classes is proposed. For the main types of metrics used in the spaces of feature values, the justified values ​​of the safety factors used in this technique are found. For a programmatic assessment of the quality of the training sample and a reasonable choice of the method for correcting outliers, it is proposed to use the permissible fractions of corrected and removed outliers in it. An algorithm for analyzing the presence of outliers in a set of training examples is given. An estimate of the complexity of the algorithm by the length of the input of the problem is given. An algorithm for evaluating and correcting training samples has been developed.

    Keywords: classification problem, classifier, decision function, training sample, precedent, erroneous data, analysis, correction, artificial intelligence, compactness hypothesis, novelty, learningg

  • Influence of various factors on the strength of inclined sections of beams reinforced with double-sided composite clamps

    Presents the results of a study of the strength of inclined sections of reinforced concrete beams, reinforced with double-sided carbon fiber clamps. An assessment of the effectiveness of composite reinforcement is given when the value of the cut span is changed, which was equal to 1.5h0; 2h0 and 2.5 h0. At the same time, the degree of influence of the initial inclined cracks on the bearing capacity of the inclined section was analyzed.

    Keywords: reinforced concrete, beam, reinforcement, composite materials, carbon fiber reinforced plastic, inclined sections, clamps, reinforcement

  • A model for assessing the timeliness and completeness of the exchange of information resources in corporate systems with a distributed registry

    The article considers a model for evaluating the performance indicators of information resource exchange in corporate systems, designed to analyze the ability of systems with a distributed registry to ensure the timeliness and completeness of information exchange. As the main indicator, it is proposed to take into account the probability of failure of a segment of the corporate system for each epoch. To find this indicator, we use probabilistic estimates of sums bounded from above by hypergeometric and binomial distributions with probability boundaries of Chebyshev, Heffding, and Schwatal. A numerical and comparative analysis of the proposed estimates is carried out.

    Keywords: distributed registry technology, information system, segmentation, block chain

  • Optimization of well repair using complexes KOS-02

    The technology of well cleaning using the KOS-02 complex and a multifunctional tool that has the ability to reciprocate and rotational motion. The scheme of force effect of the cleaning tool is given and the power parameters of the process are estimated.

    Keywords: destruction of the face zone, sand plug , equipment for cleaning wells, cleaning tool, flushing technology

  • Methodology for ensuring the timeliness and completeness of the exchange of information resources in corporate networks with a distributed registry

    The article discusses the methodology for ensuring the timeliness and completeness of the exchange of information resources in corporate networks built on the basis of distributed registry technology, which takes into account the variability of the strategy of the behavior of the distributed registry system during information exchange. The technique takes into account non-standard functions, such as the formation of a branch of the processed data and the impact of an attacker, and also allows you to determine the average value of the block generation delay time by adjusting the number of operations required to solve the block. The use of this method allows to increase the value of the indicator of timeliness and completeness of the exchange of information resources in the corporate network by 30% compared to the existing system of information exchange.

    Keywords: distributed registry technology, corporate network, information resources