This article illustrates specifically how to use least squares method (LSM) and sensitivity function to cope with parametric identification problems. The object of this task is BLDC motor. The example of BLDC can justify the application of LSM and sensitivity function method for estimating nonlinear dynamic objects’ parameters, and the application for motor controlling system in particular. The model in the article is conducted by Matlab. The output is a proof to convey that the method used in solving the problem is accurate, and proves the possibility of its application in scientific and engineering field.
Keywords: parametric identification, least squares method, sensitivity function, BLDC motor, electric drive
The article deals with current methods of evaluating the organization and management in construction under conditions of uncertainty. The typology of the failure process is given, which determines the scenario of the crisis development at the enterprise. A model of forecasting and management in a crisis is proposed, and the conceptual aspects of building this model are considered. It is proposed to improve the enterprise management system based on the analysis of the economic component as a temporary function. Recommendations are given for improving the existing organizational forms of enterprise management.
Keywords: construction organization, organizational and technological solutions, reliability assessment, construction quality assessment
Questions of accounting of actors of influence on the investment and construction cycle are raised. An example of the use of BIM-technologies in construction is considered. It describes the solution of some specific problems that arise when maintaining the quality of construction of complex buildings, taking into account the possibility of introducing modern information systems, attention is paid to the peculiarities of improving the quality of work performed.
Keywords: organization of construction; quality of design, quality of construction and installation works, BIM-technology
This article investigates methods to combine multiple data-driven models for forecasting time series. This is done in order to increase the accuracy of forecasts according to the historical error signal, such that it minimises downstream costs of forecast errors.
Keywords: time series, combination of models, accuracy assessment, forecasting, forecast accuracy
Currently, in the design and manufacture of steel products operating in conditions of heavy impact-abrasive wear, not only material is given, but also the structure of the product itself. One such detail is the friction wedge of a freight wagon trolley. In the presented work, a new design of the friction wedge of the vibration damping unit is presented; technical calculations are carried out on the strength of the presented design. The safety factors of spring suspension are calculated. All calculations were performed according to the standards for the calculation and design of new and modernized railroad cars of the Ministry of Railways 1520 mm gauge. The performed calculations indicate the high performance of the developed design, the obtained values fully satisfy the requirements for such products. The result of the work on creating a new design of the friction wedge of the vibration damping unit is to obtain a patent for utility model No. 194823, a drawing has also been developed (KI-000.00.00.001) and terms of reference for experimental design work (KI-000.00.00.001 TK).
Keywords: friction wedge, vibration damping unit, freight car truck, strength, reliability, durability, calculation of spring suspension, static deflection of spring suspension, coefficient of structural margin of deflection, coefficient of relative friction
The article considers examples of cities with a linear-elongated configuration. Issues of air pollution are considered, examples of components of pollutants coming from stationary and mobile sources are given. Statistical data on human diseases in the Volgograd region for the period 2008-2017 are presented. Considers the issues of monitoring for the city of Volgograd.
Keywords: linear city, highway, pollution, carbon monoxide, monitoring, monitoring posts, disease statistics, combined action, vehicles, noise, gas pollution, health, exhaust gases, length
The article provides a brief overview of geomechanical methods for studying the stress-strain state of the soil mass and tunnel lining. The organization of monitoring in tunnels using conventional and fiber-optic systems is considered. Criteria for analysis of monitoring data and structural strength conditions are described
Keywords: railway tunnel, construction, operation, monitoring, strain gauge, stress, strain, strength, bearing capacity
The article is devoted to the use of natural minerals in water treatment. The paper presents the results of a study of the sorption properties of the opoka. The study showed the advantages of flask membranes compared to those deposited with silicic acid. The optimal conditions for the modification of the flask were determined, which make it possible to purify water from metal impurities to the required level.
Keywords: groundwater, water purification, deferrization, membrane, deposited membrane, sorption methods, flask, polyacrylamide
the article describes a variant of setting sequential algorithms in the form of bipartite graphs by further defining them, which makes it possible to work with algorithms using graph theory methods in the future. Two forms of the task are considered: modular and functional-predicative. The possibility of setting the algorithm in table-predicate form is shown. It is concluded that in addition to the generally accepted methods of setting the algorithm, it can be set in matrix-predicate or table-predicate form, which allows using methods of matrix theory and methods of predicate theory when working with algorithms. setting the algorithm in matrix-predicate form avoids isomorphism when performing algebraic and set-theoretic operations on it.; setting algorithms in matrix-predicate form allows you to perform almost any operations on them
Keywords: graph-algorithm scheme, sequential algorithm, predicative block, functional block, pre-definition, bipartite graph, table-predicative form, graph theory, isomorphism
There is an analysis of the urban development location and the capacity of public spaces for cultural and educational purposes was carried out using the example of cultural centres for Volgograd. The normative and actual material security is determined separately for each administrative district and whole sity. There are suggestions on the advisability of erecting new cultural objects.Dynamics of modern cities is taking into account.
Keywords: planning, cultural centre, cultural and social structure, standard of material security, actual material security
One of the most pressing problems in the oil and gas industry is numerous pipeline accidents that require innovative solutions. This article analyzes a promising method of repair using composite couplings, which include many advantages compared to steel structures. The strength characteristics of the couplings are also given and their installation process is described.
Keywords: Oil pipeline, overhaul, reinforcing composite coupling, composite materials
The calculation algorithm is given and various options for solving the problem are considered when changing the parameters of the design scheme of the rod system on the example of a beam in the MS Excel software environment together with the MathCAD package. The proposed approach allows you to combine formulas, graphics, and calculation results on a single sheet, which is especially useful in the educational process. It contributes to a more conscious perception of the calculation process by students, allows them to implement various forms of distance learning in information technologies.
Keywords: the core of the system, algorithm, modelling, integration, information technology
The authors of the article consider external socio-economic and internal motivational factors in the formation of reproductive behavior of young families living in the Rostov region. Based on empirical data, the authors of the work conclude that young spouses occupy quite active economic positions in the region we are studying. These professional strategies have a dual effect on reproductive behavior, determining the choice of one-child family model in the region
Keywords: model, cognitive analysis, family, young family, life strategies, value orientations reproductive behavior
The directions of modern research in the field of adaptive error correction, which can be applied when transmitting images in JPEG 2000 format over a noisy channel, are examined. Adaptive correction at the network level allows you to maintain a given percentage of packet delivery. Uneven protection at the application level is intended for use in broadcast broadcasts and allows the consumer to receive an image of various quality depending on the state of the network. Adaptive uniform protection at the application level is focused on point-to-point transmission and is aimed at receiving the maximum image quality by the receiver. The network layer tools discussed can be combined with the application layer tools.
Keywords: adaptation, noise-proof coding, forward error correction, noisy channel, JPEG 2000
To assess the impact of various groups of sources of emissions in urban pollution, there is a method that can be called the main one - the assessment of the contribution to total gross emissions. But this method does not take into account the significant features of dispersion of pollutant emissions in the atmosphere, as well as the specifics of the mechanisms of formation of concentrations of pollutants at a specific point in the city and the calculation of complex indicators of the level of air pollution in urban areas. The authors proposed a procedure for calculating the atmospheric pollution index for source groups using the “summary calculations” tool. The calculations were carried out on the licensed software product "Ecologist-city". Based on the calculations, conclusions were drawn on the reliability of determining the influence of various groups of emission sources on air pollution in the city of Krasnoyarsk, based on the assessment of contributions to the total gross emission in the city.
Keywords: atmosphere, air, ecology, ecology of urban areas, environmental safety, summary calculations, IZA