In this article, in terms the language of queuing networks, the problem is formulated finding the optimal value the average response time of the system to the requests all users for distributed information processing systems implemented on the basis of the file-server architecture, two-level and three-level client-server architecture with a fixed cost of downtime, including the cost downtime for users, the cost of downtime for a data transmission channel and the cost downtime for service nodes. An algorithm for solving this optimization problem is presented.
Keywords: distributed information processing system, file-server architecture, two-level client-server architecture, three-level client-server architecture state space, average system response time, loss cost, stationary probabilities
This article is devoted to the study of the problem of power supply of low-power consumers distributed along the path of electric Railways AC, which can act as a system of sensors diagnostics of automated control systems of various objects located along the contact network. The main part of the article is devoted to the description of the primary model necessary for further consideration of such a method of electric power supply and experimental modeling.
Keywords: contactless power transmission, capacitive communication, power supply, contact network, electric Railways
An idea is introduced of the directing structures of the director and reflex types that contribute to the formation of air flows, which in a given way contribute to an increase in mechanical power on the shaft of its rotor. These structures can be used to amplify the moment on the rotor shaft by increasing its useful interference with the stator. Qualitative considerations about the influence of the introduced guide structures are confirmed by the introduction and numerical aerodynamic calculations of two modernized designs of a promising vortex wind power installation, considered in the previous works of the authors. The most optimal variant of rotor modernization was selected, which made it possible to increase the power on its shaft by an average of 45% relative to the corresponding power for the design of a wind turbine with an initial rotor shape in the operating range of wind speeds from 1 to 12 m / s. The materials of this article can be used to design the optimum aerodynamic power criterion for the rotor of wind power plants, their stations, as well as integrated power power plants, including a wind power plant as one of the renewable sources of energy.
Keywords: wind power installation, airflow structuring, director-type guide structure, reflex-type guide structure, vortex structure, rotor aerodynamic torque, aerodynamic optimization by the criterion of maximum power, numerical aerodynamic calculation, sliding gr
Mathematical models with analytical properties are needed to create modern stabilization systems for various objects and technical systems. This is due to the fact that most of the existing methods for the synthesis of automatic systems are based on mathematical transformations of models of control objects. However, for complex objects and systems, these models are obtained experimentally. Moreover, the experimental data are approximated by various well-known methods. If the dependences are essentially nonlinear in nature, they are approximated by sections. Such a fragmented model as a whole is not analytical, which excludes the use of many well-known methods for the synthesis of nonlinear stabilization systems. In these cases, it is advisable to use the new Cut-Glue approximation method developed at DSTU, which allows one to obtain an analytical model of an object from piecewise approximations. This analytical model allows you to apply the analytical method for the design of quasilinear control systems for nonlinear objects. In this paper the propoused approach is illustrated by example of the design of a nonlinear system for stabilizing the flight altitude of an airship.
Keywords: stabilization system, analytical synthesis, nonlinear control object, mathematical model, quasilinear form, experimental data, fragmentary model, multiplicatively additive approximation
The work describes the implementation of the cognitive set-theoretic approach proposed earlier for modeling complex systems. The article describes in detail the application of the analytic hierarchy process and the cluster approach to determining the cadastral cost of land and selecting the site according to predetermined criteria on the example of Taganrog. Calculations and visualization of results were carried out using the software products STATISTICA and QGIS
Keywords: cognitive theoretical-multiple approach, the analytic hierarchy process, cluster approach, cadastral cost
This article describes the territories of the northern regions of the Russian Federation, the problems of the distribution of permafrost soils (MMG), and discusses the difficulties encountered in the construction of roads in difficult geocryological conditions. The introduction of heat-insulating layers of foam glass rubble into the design of pavement is proposed. The basic physical and technical characteristics have been analyzed, and the key properties of foam glass rubble are determined. The article describes the process of production of foam glass, the advantages that allow the use of this material in various fields of construction. Typical road structures made of soil are considered. A comparison is made of a typical construction of pavement made traditionally from soil (high embankment) with a construction with a heat-insulating layer of foam-glass rubble. The advantages have been listed when using structures using foam glass rubble in road construction.
Keywords: foam-glass rubble, road construction, automobile road, heat-insulating layer, frost, north, glass, construction, soil, materia
The article is devoted to the development of a complex of mathematical models describing the functioning of a data storage system based on solid-state drives using deduplication technology. The mathematical model of the user application generates a load on the system as a stream of requests, randomly sized according to the Pareto law, and with random time interval between requests. Requests are received at the input of the storage system into the network service model, then to the VDO deduplication system model, then to the software RAID model and, finally, to the solid-state drive model for read/write operation. Due to the nature of SSDs, system performance in read and write modes is modeled separately, taking into account the different speed characteristics of RAID-5, RAID-6 and RAID-10 arrays. The mathematical model of the reliability of each RAID array is based on the Kolmogorov-Chapman system of equations for calculating stationary probabilities describing transitions between states in a discrete Markov chain. The durability of the system is determined through the model for assessing the exhaustion of the recording resource of solid-state drives. The mathematical model for estimating the storage cost includes the costs of equipment, resources and maintenance over the entire operation period of the system. The final result is a mathematical formulation of the problem of data storage system optimal design, which allows selecting the system architecture and parameters that are optimal in terms of a combination of factors – reliability, speed and cost of data storage.
Keywords: mathematical modeling, data storage system, performance, reliability, solid state drives, RAID array, optimization
Cities around the world lack land resources, despite the fact that the housing stock is in a state of extreme deterioration. The solution to this problem becomes such a concept as renovation - the process of updating urban space. This mechanism is currently provided for in the Town Planning Code of the Russian Federation, but for a number of reasons its implementation in practice is limited. Renovation is necessary in the prevailing conditions of the modern world in order to adapt the spaces of former industrial zones for their use in an already new format. The vast majority of industrial companies cease to operate within cities, and their territories turn into neglected neglected development, isolated from the urban social environment. The authors of this article reviewed and analyzed the benefits of implementing renovation programs for residents of the Russian Federation.
Keywords: renovation, eco-construction, depressed territories, modernization of urban areas, development of regions, redevelopment buildings
The article discusses the results of the development of a feasibility study for the provision of services for the export of concrete products in Perm, presents a market analysis in terms of determining the number of residential buildings connected to the water supply system, but not connected to the centralized sewage system, and discusses problems that impede the development of the project The analysis of the actual and planned number of specialized motor vehicle flights was carried out, revenue for the export of concrete products was determined, priority directions were developed eniya activities dedicated utilization of the company
Keywords: household liquid waste, local treatment facilities with passive aeration, local treatment facilities with active aeration
Results of modeling and a pilot study of a low-pass filter with a cut-off frequency of 4 GHz are given. Modeling of the filter was carried out in MicrowaveOffice application program package. The experiment was made on the vector analyzer of RXA chains. Results of modeling and an experiment conform to the imposed requirements, namely: - cut-off frequency is 4 GHz; - losses in bandwidth no more than 3 dB; - an obstacle on the second harmonic of cut-off frequency not less than 60 dB; - wave resistance of an input and exit of 50 Ohms.
Keywords: low-pass filter; cut-off frequency; losses in bandwidth; losses in an obstacle band; modeling; experiment
Currently, special attention is paid to creating a comfortable urban environment, as a result of this there is a need to create projects that contribute to improving the quality of life of the population. In this paper, we consider two subprograms of the Rostov region: "Improvement of public territories of municipalities of the Rostov region" and "Improvement of the courtyards of apartment buildings in the Rostov region", operating under the state program "Formation of a comfortable urban environment." The number of transformed public and house territories from the moment of implementation of these subprograms of the Rostov region is analyzed.
Keywords: comfortable urban environment, state program, land improvement, public areas, transformation
The article deals with the issues of plant protection by electroaerosols of chemicals. Revealed General regularities of penetration electroaerosols jet in the topsoil and deposition of drops of electroaerosol in vegetable elements. The estimation of the depth of penetration of the aerosol jet into the plant layer and the intensity of deposition of the aerosol on the protected plants is given. This article is of interest to a wide range of readers dealing with the issues of electrical aerosol treatments in agriculture.
Keywords: electroaerosol, the jet flow of the electrical aerosol, aerodynamics jet stream, plant protection, plant layer, the charge drops electroaerosol, gravitational and electrostatic precipitation
he article is devoted to the question of selection of aerodynamic parameters of drying in the apparatus of the filtered-fluidized bed of dispersed particles – carbon-black containing wastes materials and granules of sodium salts in solution of modeling problems. The design of the studied gas pressure distribution grid fluidized bed of dispersed materials of the tray kind provides the possibility to efficiently fulfill the drying process at relatively low speeds of the drying agent. It is allowed to reduce the removal of particles of material from the bed and its exhaust into the atmosphere. The average flow rate of gas motion and the number of fluidization for the main stages of the filtered-fluidized bed of the studied materials and aerodynamic parameters (drop pressure losses) are determined. It was found the fluidization number in the range 1.25-1.5 and the bed height was about 0.25 m. The total aerodynamic drop pressure losses of the dispersed materials’ bed and had acceptable meanings within range from 90 to 130 kg / m2. For the recommended range the coefficient was equal 30-45. Data were obtained on the phases of fluidization, the values of the aerodynamic parameters of drying, and the areas of operating conditions that provide a fairly uniform circulation of the material in the layer and reliable operation of the apparatus.
Keywords: modeling, drying, waste, dispersed material, fluidization, bed, velocity, aerodynamics, pollution, atmosphere
The article provides an analysis of the proposed system for protecting confidential information of the organization. The rationale for the need for comprehensive protection is given, since the unidirectional system is not effective enough, leads to early failures and the loss of important confidential information, as well as an adaptive monitoring unit
Keywords: confidential information protection system, protection subsystems, integrated confidential information protection system, probabilistic assessment, adaptive monitoring
Models of monitoring program generation systems are proposed that can significantly reduce the cost of time and other resources for monitoring complex technical objects. Systems are considered at several levels: subsystems and modules, communication links, usage scenarios, physical representations. A technique for adapting system models to subject areas is proposed.
Keywords: complex technical object, monitoring, models of software systems, program generation