The choice of the installation location of compensating devices is determined by various factors that must be taken into account when performing calculations. The location of reactive power compensation devices is determined based on the results of mathematical modeling and the optimal operating mode of individual sections of electrical networks. The paper presents the results of modeling, considers the uncertainties encountered in solving the problem of placement of compensating devices.
Keywords: compensating devices, electric power industry, active power losses, minimum reduced costs, uncertainty, power gain, optimization criteria, electrical node, damage vector, optimization
Purpose: The purpose of the study is to identify the duration of the implementation and linkage between procedures and the development of a basic organizational and management model for their passage by the technical customer (developer) at the stages of pre-design and design preparation of the facility for construction. Carrying out this study is relevant, since today there is a single regulation for a technical customer (developer), describing the sequence and the possibility of paralleling and the duration of functions during the passage of procedures at the stages under consideration. Methods: The conducted research is based on the analysis of scientific and technical literature, regulatory and technical, regulatory and legal documents, the method of expert assessments is also applied. Results: The processing of the arrays of data from the questionnaire survey of experts made it possible to determine the intervals of the duration of the procedure by the technical customer (developer) and to link them with each other in time at the stages under study. As a result, a basic organizational and managerial model was developed for the passage of procedures by a technical customer (developer) at the stages of pre-design and design preparation of an object for construction. Conclusions: The use of the basic organizational and management model by organizations performing the functions of a technical customer (developer) will simplify the planning and management of processes when going through the procedures at the stages of pre-design and design preparation of an object for construction.
Keywords: technical customer, developer, pre-project and project preparation, organizational and management model
The presented article describes the modeling of a communication system (hereinafter SS) organized by a plurality of communication nodes of a public communication network (hereinafter SS SSN) and its elements. The task of modeling is to obtain interrelated initial data on the set of features for each investigated SS of the SSNS at each moment of the model time, taking into account the implemented activation processes and the logic of SS functioning. The process of functioning with the SS as a source of features is studied using a complex analytical and simulation model, since deterministic and random factors are taken into account for its development. The manifestation of signs is a complex process, since the SS is constantly in dynamics. However, the increasing intensity of the increase in the use of communication means and the load in communication channels leads to an increase in the number of manifested set of signs. The reasons for the manifestation of many signs are such factors as: dynamics of movement of the USS of the SSOP; modes of operation of SSOP elements, etc. All of these factors are used in the model as activating the manifestation of many features.
Keywords: communication system, public communication network, communication node, sign of a system element, information direction, activating factor
At present, the number of means for collecting information about the characteristics of elements of a public communication system is increasing. Databases.
Keywords: database, monitoring systems, information, resolution, processing of information arrays, similarity rate, process automation, public communication system, communication system elements
The transition of a fire from one phase to another is represented by a change in the states of the Markov chain. The phases of free combustion, extinguishing and elimination of consequences are considered. The initial data for constructing a Markov model is a sample of observations of response time indicators. Recursive expressions are constructed for estimating the transition probability matrix of the Markov chain. The predictive capabilities of the constructed Markov model of the fire development process are illustrated.
Keywords: fire phase, Markov chain, transition probability matrix, termination probability, recurrent estimation, vector of initial probabilities, prediction
This paper reports on the results obtained on the diagnostics of a steam pipeline of a thermal power plant; it analyzes the effect of thermal fatigue on the structure and properties of the 12Kh1MF steel and possible reasons for the emergency destruction of steam pipeline elements before the exhaustion of economic life. Ultrasonic testing and additional heat treatment are proposed to be used for the detection and elimination of structural inhomogeneity in the metal. The applicability of statistical technique to analyzing data on the loading history of a steam pipeline is studied, which enables us to evaluate the damaging effects of loading cycles and to develop a plan of preventive measures, as well as to increase the accuracy of predicting the residual life of steam pipeline elements.
Keywords: metallic structure, diagnostics, degradation, steam pipeline, thermal fatigue, microstructure, mechanical properties, residual life
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
Practice shows that today the main trend in the development of the modern construction industry is associated with the expansion of the use of cast-in-situ reinforced concrete. In many cases, cast-in-situ reinforced concrete has better construction and technological properties (compared to precast concrete, metal) and allows you to freely implement a variety of architectural solutions with economic benefits. In turn, modern advances in the technology of concrete work would not be possible without the appropriate technical base. This article analyzes the use of construction machines in the construction of a cast-in-situ reinforced concrete skeleton of civil buildings on the example of objects realized in Yekaterinburg. A study was conducted, according to the results of which the manufacturers of construction equipment were identified, as well as the technologies prevailing in monolithic housing construction in the city. According to the terms and cost of construction, which are the defining elements of the construction sector, one indicator was allocated for a technical and economic comparison, the results of which determined the need to develop a comprehensive feasibility study of the use of construction machines in the construction of cast-in-situ load-bearing reinforced concrete structures, as well as the development of methods for selecting machines, which in the future will reduce the construction time of the cast-in-situ skeleton of the building, increase the payback of monolithic civil housing construction and the efficiency of construction from cast-in-situ reinforced concrete.
Keywords: civiс building, cast-in-situ reinforced concrete,construction machine, load-bearing structure, technical and economic comparison, concrete mix, building skeleton, construction machine, construction, civil engineering
Suspended ceilings constructions can improve the sound insulation of air and impact noise in civil buildings. To minimize the volume of the room, two types of suspended acoustic ceilings are most often used. They are: with the attachment of the structural shell of the ceiling close to the floor slab, and at a low suspension height. The influence of the slab's surface density on the correction to the sound insulation, which is created by the suspended ceiling, both in the first and in the second type, is considered. A method for a correction calculation for the sound insulation due to a suspended ceiling in these cases is given. At a minimum height the method is based on taking into account acoustic power's radiation coefficient of the shell. While for the low suspension height the method deals with the vibration's transmission from the floor slab to the ceiling's shell through the air layer and through the metal fasteners, that in this case become acoustic bridges. As a result, the formula of frequency response for sound pressure lowering, due to the sustained ceiling structure, is obtained. The influence of plasterboard suspended ceiling's perforation on the sound insulation of the entire floor structure is evaluated.
Keywords: suspended ceiling, impact noise isolation, airborne noise isolation, acoustic radiation power, limit frequency, acoustic bridge, acoustic impedance, vibration velocity level, porous and fibrous material, perforated plasterboard
The possibility of using nonlinear effects in hydroacoustic systems with parametric radiation mode for profiling the bottom and bottom sediments attracts the attention of both domestic and foreign specialists. The use of parametric antennas in hydroacoustic equipment allows, due to their high directivity and low side field level, to increase the information content and accuracy in detecting and determining the coordinates of underwater objects, and to obtain additional features for recognition. The efficiency of using a parametric profiler for solving problems that require high resolution is justified. A block diagram of a parametric profiler for studying the layered structure is developed. The features of the signal generator and the amplification unit are considered. The characteristics of the radiating antenna were measured under laboratory conditions. It is shown that the directivity characteristic is constant in the operating frequency range and the acoustic power at the output makes it possible to solve the tasks of sounding up to 10 m into the ground. A record of the soil profile was obtained, confirming the operability of the system. In the future, the results will be used in full-scale conditions with the use of cepstral echo processing.
Keywords: profilograph, parametric antenna, kepstr, block diagram, signal generator, power amplifier, directional pattern, amplitude-frequency response, pump antenna, ground profile
In this work, a survey of the hot water supply system from the boiler house No. 2 of Energoservice LLC was carried out. The daily schedule of hot water released for sanitary needs is given. The existing scheme of the boiler burner on-off control system is considered. A method for stabilizing the hot water preparation process by increasing the burner shut-off settings at the hour of the highest water consumption is found and described, and their values are found experimentally. A scheme has been developed, assembled and tested that allows you to adjust the operating mode of boilers at a strictly specified time of day. The proposed measure allowed us to solve the problem of selling hot water to consumers of a given quality during the maximum water intake period. In addition, the reduction in the generation of thermal energy for heating hot water at night and on weekends allowed for a 13.87% reduction in natural gas consumption in 2020.
Keywords: hot water supply, fuel consumption, pumping station, circulation line, conditional fuel, mode, boiler unit
The article discusses the natural factors that should be taken into account when designing highways. The following factors have a significant impact on the design of roads: terrain, engineering-geological and hydrogeological structure, climate, etc. The variety of natural factors is taken into account comprehensively in the design. They also take into account the negative impact of road construction on the environment. The terrain has an impact on fundamental engineering decisions, the volume of construction work, and ultimately not only on the construction cost of the highway and transport operating costs. In relation to the design of roads, there are five categories of terrain according to the complexity of road construction. Depending on the geological conditions, sometimes an extension of the highway route is used or expensive engineering measures are provided. It should be borne in mind that the use of the latest materials, road structures and new techniques for the production of construction areas is becoming less and the problems of seasonality of road reconstruction are becoming less relevant.
Keywords: highways, terrain, climate, slope, natural factors, engineering and geological process, surveys, tortuosity, lengthening of the route, road clothing
The article is devoted to the possibility of applying the methods of successive approximations in the analysis of the instantaneous scheme of the traction network. The described approach allows to improve the accuracy of modeling dynamic modes of operation of traction power supply sections, and also allows to significantly improve the process of modeling diagnostics and control systems of electric rolling stock at the design stage based on a more accurate model of dynamically changing input parameters of the traction network, depending on their required level.
Keywords: traction network, instantaneous circuit, diagnostics, simulation, recruitment model
The methodology of numerical experiment of laying with closed method by methods of horizontal-directional drilling, brown-screw drilling, forcing, microtonneling has been developed. Some features of the construction of cases for penetration by collectors under existing highways, including general information about the used materials of the cases, are given. A selection of controlled factors and experiment planning, system stability check, results reliability analysis was performed.
Keywords: collector, numerical experiment methodology, microtonneling, horizontal directional drilling, brown-screw drilling, puncture, forcing, motorway, case, reinforced concrete, metal pipes
The paper discusses approach to voice recognition, that allows to use tools of Google Cloud Speech platform for editing source code for programs, using audioprocessing, editing distances and substitution tables. The paper discusses issues of editing source code on mobile devices and the issues, which does not allow using tools from Google Cloud Speech platform directly, like not recognizing certain keywords. The paper suggests new method, which combines substitution tables and editing distances for solving the issues. This approach can be used for editing source code for programs, using mobile devices. The paper offers a prototypr of web-application, which allows to edit source code and uses this approach and, also, allows to submit changes to Github source code hosting platform and a popular instant messenger Telegram.
Keywords: voice recognition, mobile devices, source code analysis, formal languages, editing distances