The article gives a systematic review of the architectural composition of the oldest capital urban complex of the North Caucasus – the fortress of Derbent. On the material of historical sources stages of urban planning are reconstructed, the role of economic and foreign policy factors in the development of the urban environment in historical retrospect is shown.
Keywords: industry history, architecture, urban planning
The article provides a systematic review of measures to improve the quality of installation work. The question of improvement of installation works of building structures is studied. A set of tools for improving the quantitative assessment of installation work is proposed.
Keywords: organization of construction, quality management
On the basis of the mathematical apparatus of Queuing, a mathematical model for the diagnosis of the technical condition of vehicles with electronic control units. The developed mathematical model of vehicle diagnostics in the framework of discrete-event paradigm. Numerical experiments to assess the effectiveness of diagnostics are carried out.
Keywords: cars, electronic control unit, diagnostics, Queuing system, efficiency, operating costs
The article is devoted to the actual problem of increasing the complexity of user passwords in systems with remote access to increase their information security. It proposes a method based on the integrated application of the input characters of the password and the time intervals between them. In the article, using the inhibitor time network Petri, a model of a dynamic password setting process was constructed, on its basis the process of forming a reference image and user authentication is described. The above calculations of increasing the complexity of the password prove the effectiveness of the proposed approach.
Keywords: authentication, password, dynamic process, Petri net, complexity, password retrieval
Accelerating the pace of construction of modern and affordable housing with energy efficiency class not lower than B +. This implies the creation of technologies that contribute to an increase in the production of relatively inexpensive heat-shielding materials produced from mineral melts, and used in the construction of flat roofs or used coatings. The developed materials possess a complex of valuable operational properties. There is a significant improvement in the characteristics of the material characteristics - thermal conductivity, compressive strength, water absorption by weight and cold resistance. Improving the insulating properties is enhanced when additives are present in the formulations that saturate the system with lead oxide.
Keywords: energy efficiency, heat protection, silica opoka, fluxing additives, silicon, calcium, high-temperature foaming
The enormous wood resources of the forests of Russia and foreign experience indicate the need for innovative development of the country's forest industry. In this regard, it is necessary to determine the most promising areas for the development of logging. The results of the system analysis revealed the universities that are most actively involved in research and development in the forest industry, as well as important areas of this research and development.
Keywords: research and development, forest industry, scientific and technical information, development directions, system analysis
This article discusses the economic approach to the choice of the mode of continuation of the system in the face of partial failure. It discusses strategies related to the continuation of work in conditions of partial failure or cessation of operation until the completion of the operational restoration process. The characteristics of each of the strategies are presented in a comparative aspect for the continuation of the operation of the object in the post-failure period or the delay in operation for the duration of the restoration. The dependence of the time recovery parameters and the times defining the moment of identifying a partial failure in the coordinates of the time axis from the beginning of the working cycle to the next scheduled maintenance has been revealed. The resulting mathematical expressions allow, under certain conditions, to justify the choice of one of the two strategies considered. For more complex cases, it is proposed to use expert approaches to take into account additional characteristics of the process, such interregional period, performance and acceptable risks associated with working in conditions of partial failure. The article provides graphs illustrating the change in reliability characteristics in two ways of developments of events related to the adoption of a decision to continue work.
Keywords: partial failure, the coefficient of gain in terms of work, the probability of uptime, recovery time, time in the post failure period
The dependence of influence of size of a bend on tensely strained state of load-bearing frames of a covering is analysed. On the basis of the received results the maximum corner of a bend of the metal corners reducing a carrying capacity of farms is defined.
Keywords: a rafter farm, bend, tensely strained state, a moment of inertia, a radius of gyration, a barycentre
The article deals with the work of mechanical absorbers, where the working body is presented in the form of a rotating cylinder. The analysis of interaction of liquids and a working body in similar devices is made. The mutual influence of liquid layers and the action of the working body are considered. The estimation of the force factors of the dynamic layer entrained by the rotating cylinder is obtained. The study presented in the article will help in the preparation of engineering methods for calculating the operating and design parameters of devices.
Keywords: absorber, emulsion layer, capillary forces, emulsion, static meniscus region, capillary pressure, immiscible liquids, rotating cylinder, liquid, Navier-Stokes equation
The development of modern technology makes increasingly stringent requirements for materials, and improving the reliability and durability is an urgent task for many industries. One of the most important elements of the automatic coupling device of the car is the absorbing device. The parts included in it must meet high standards, be reliable and provide the necessary hardness and mechanical properties of the materials throughout the life cycle of the car. One of these parts included in the friction unit of the absorbing device is a movable plate. In the present work, an example of modernization of the absorbing apparatus through the use of modern methods of modeling and manufacturing of a fixed plate is given. The technical result is to reduce consumption of materials of the movable plate, and to simplify the manufacturing process of the plate by making it from rolled steel.
Keywords: Absorbing apparatus, modeling, mobile plate, energy consumption, friction unit, friction, wear resistance, reliability, durability
The article provides a solution to the problem of the stress-strain state of the base in the field of karst dip. The problem is considered in the linear formulation for a layer of bounded thickness weakened by a cylindrical notch. The solution is obtained in polynomials based on the use of the Solyanik – Crass stress functions satisfying a quasi-harmonic type differential equation. The main task was solved on the basis of using the principle of superposition. The verification of the obtained solution was carried out on the basis of a comparison of the components of the stress and displacement tensor with the results of numerical solutions. Graphs constructed using the Mathcad mathematical complex and the Plaxis software complex were considered. Their analysis showed good convergence of the results.
Keywords: Karst, cylindrical cavity, stresses, displacements, isopolis, linear formulation, mixed problem
The main goal of modernization in the field of education in the world is to achieve a new quality of the educational process corresponding to the new socio-economic conditions. This requires effective organization of the educational process, which will facilitate the search and development of abilities in each student. The result of the teacher’s work should be an active, creative, and cognitive organization of students' joint activities. Also important is the development of students' skills of the 21st century, which would be useful in their future professional activity, where the latter requires the ability to work not only with information, but also with people. These can be communication skills and teamwork skills, flexibility and adaptability, the use of the aggregate intelligence of a group that is a joint activity to achieve the goals.
Keywords: Internet, Web 2.0 tools, social network, cognitive activity, network services
This article discusses the main problems faced by experts in the construction and technical expertise of real estate. The measures that can improve the quality in the performance of judicial construction and technical expertise are considered.
Keywords: optimization, judicial construction and technical expertise, litigation, major problems, construction contract, construction and installation work, completed
There are represented scheme and design of duplexer for the 300-344 MHz radio station. Simulation of duplexer was implemented in Microwave Office environment. Experimental research was executed on the complex transmission coefficient measuring instrument such as “Obzor-103”. There are shown amplitude-frecuency characteristic of receive and transmission channels. Comparison of the simulations results with natural experiment proving the identical.
Keywords: Filter, duplexer, amplitude-frequency characteristics, receive channel, transmission channel
Offers on the rational organization of control of durability of concrete according to GOST 18105 for modular products, commodity concrete mix and monolithic designs are presented. The concept of "moving analyzed period"is introduced. It is shown that it is not reasonable to use the control scheme for the control of the indirect indicators and the development of rapid methods for assessing the strength of concrete in the control of commercial concrete mixtures. The rational organization of concrete strength control of monolithic structures using direct and indirect methods is proposed. The groundlessness of application of statistical methods of control at control of durability of concrete of monolithic designs is shown.
Keywords: control of the concrete strength, the analyzed period, the control scheme, the actual concrete strength