The article considered the propagation of a long impulse signal in a hydroacoustic waveguide. A solution is given for a replica of a impulse signal in the second approximation of the dispersion theory. The propagation of a single-mode and multimode impulse in a Pekeris waveguide with a bottom in the form of an absorbing half-space is simulated. The acoustic properties of the half-space correspond to medium sand with an average grain size 0,3 mm. The result of the solution in the second approximation of the dispersion theory is compared with the result of the simulation of the impulse replica obtained as a convolution of the input signal with the impulse response of the waveguide. The disadvantages of the solution in the second approximation of the dispersion theory are shown and analyzed. It is shown that the theory of dispersion incorrectly reproduces the transients when the signal is switched on and off in cases where the signal frequency lies near the critical frequency of the first or second mode. It is shown that the theory of dispersion correctly reproduces the envelope of a multimode impulse signal.

Keywords: impulse signal, normal modes, group velocity, dispersion theory, intramode dispersion, intermode dispersion

The paper provides an overview of the applications in central heating points (CHP) of technologies and equipment to improve energy efficiency and quality of heat supply from district heating systems. The main equipment and characteristics of the hot water supply system taken as an example of the central heating station "MGU" are given. Described is the method of choosing the heating circuit of the central heating station from the ratio of the maximum loads of hot water supply and heating. For the adopted example of a central heating station, based on the above characteristics, the main indicator of energy efficiency is the specific consumption of electrical energy for the transport of thermal energy. Factors that have the greatest impact on this indicator: coefficient of uneven consumption of "hot water"; quality of regulation of hot water supplied to the hot water supply network; precise control of the productivity of the boosting and circulation pumping stations. The standard total power of the pump drives has been determined to be 13.58 kW and the range of actual power is from 10.79 kW to 22.04 kW.To reduce the influence of factors in the control scheme, it is proposed to use flow (pressure) regulators to maintain a constant direct-acting pressure drop. Use the pressure (pressure difference) of hot water discharged to the DHW system and returned from the system as balancing forces for this regulator. The parameters of hot water of rational modes of operation of the hot water supply system from the central heating station "MGU" were determined: temperature of hot water at the outlet of the heat exchange equipment 75 ° С; hot water pressure at the outlet of the heat exchange equipment 45 m; hot water pressure at the inlet of the circulation pump 25 m. The implementation of the proposed option without the inertial control scheme for the temperature of "hot water" and the developed rational modes of operation of the hot water supply system, according to the assessment of efficiency indicators, will reduce the specific consumption of electrical energy in the central heating station by 28.4% from 0.631 kW * h / m3 to 0.452 kW * h / m3.

Keywords: central heating station, hydraulic mode, flow regulator, pump characteristic

It is indicated in the article that the study of the electron bunching process in the drift space of a transit klystron is an urgent task that allows one to establish general laws applicable to more complex models. In this connection, the behavior of the pre-modulated electron beam in the drift space of the transit klystron has been investigated. A numerical model has been implemented that takes into account the effect of space charge fields and the interaction of charged particles with elements of an electrodynamic system. A series of numerical experiments with different values ​​of the current and initial velocities of electrons, as well as their comparison with theoretical data, have been carried out. As a result of numerical experiments, data were obtained that characterize the dynamics of the electron flux in the drift space of the transit klystron at different values ​​of the initial velocity (0.5 s, 0.9 s) and cathode current (10 mA, 1A, 10A).

Keywords: flyby klystron, mathematical model, numerical simulation, large particle method, particle-particle method, drift space, convection current distribution, electron flow, multithreaded calculations, system of differential equations

For a decision maker, the problem is to choose the best franchise on a wide variety of existing Russian and foreign alternatives in the face of uncertainty. For a successful business, a decision maker needs to analyze the data on all the criteria among the selected franchises. In this paper, 5 alternatives- franchises of linguistic centers were considered. To calculate the weights of the importance of the criteria, the hierarchy analysis method was used. By fuzzy criteria using the Fuzzy VICOR method, a comparative analysis of several franchises was conducted. As a result, the best franchise for doing business was revealed. The Fuzzy VICOR method allows to get an effective result even in the conditions of uncertainty of input data.

Keywords: decision making, franchising, fuzzy decision making method, hierarchy analysis, defuzzification, Fuzzy VICOR

A model that implements a method for assessing the security of a special purpose automated information system is considered in the article. The model takes into account both the intensity of the load on the system and the number of channels as a means of protecting information from DDoS attacks based on the combination of theoretical and empirical approaches to assessing security of special purpose automated information system. The transition from a theoretical model using empirical states and continuous time to a discrete time model is applied to build a new model. The purpose of the work is to develop a model that implements a method for assessing the security of a special purpose automated information system against DDoS attacks based on a theoretical-empirical approach to modeling information protection means against DDoS attacks.The following tasks are solved in the article: analysis of known models that implement the method for assessing the security of special purpose automated information system from DDoS attacks; the model which implements a method for assessing the security of special purpose automated information system based on a theoretical-empirical approach to modeling information protection against DDoS attacks is being developed. The use of the new model makes it possible to apply both empirical values obtained as a result of measurements or modeling, and a theoretical basis for modeling information protection means under the influence of DDoS attacks, taking into account their characteristics, which will be reflected by the income function and the choice of the optimal mode of functioning of the special purpose automated information system in discrete moments in time. When synthesizing the models presented in the article, the lack of the static nature of the assessment of the security of the special purpose automated information system was eliminated, the intensity of computer attacks such as DDoS, which dynamically changes both the parameters evaluating the means of protection and the probability of the system being in critical states, was taken into account.

Keywords: automated system, modeling, security assessment, queuing system, probabilistic assessment, DDoS attack

A method for determining the optimal value of the heat transfer resistance of a three-layer exterior wall of a country cottage building is presented. As an optimization criterion, the specific consumption of thermal energy for the weekly cycle of operation of the building is selected. As a result of the study of the function describing the total specific energy consumption for heat loss compensation and heating of 1 m2 of the outer wall, an analytical expression was obtained to determine the optimal value of the heat transfer resistance. Based on the obtained solution, the thickness of the monolithic expanded clay concrete used as a structural and thermal insulation material in the outer wall is optimized. An analytical relationship is obtained to evaluate the energy-saving effect due to additional insulation of the outer wall of a country cottage.

Keywords: intermittent heating, heat transfer resistance, enclosing structure, energy consumption, heat protection characteristics

The object of the research, the result of which is the presented work, is a comprehensive system of spatial data of the railway infrastructure, within which a high-precision system of coordinates of the Russian Railways has been created, and methods definition of normal heights in the Baltic Heights System 1977. The strategy and prospects for the development of high-speed transport highways (VSM) have been described. Methods for determining normal heights at research sites are given.

Keywords: monitoring, buildings, facilities, engineering and geodesic research, laser scanning, GNSS receivers, design, construction, observations, geodesic measurements

Setting the indirect reinforcement in the form of cross welded mesh is one of the effective ways to increase the strength and deformation characteristics of compressed concrete. When performing engineering calculations of structures with indirect reinforcement, in order to ensure the required reliability, it is necessary to use the design values of the strength of materials. At the same time, initially the calculation formulas were derived and analyzed for the experimental average strength values, which are significantly higher than the design ones. Based on the results of the calculations, it was found that a simple substitution of the calculated strength values in the formulas leads to an overestimation of the strength and ultimate compressibility values of concrete with indirect reinforcement.

Keywords: indirect reinforcement, welded mesh, volumetric stress state, compression diagram

" This article deals with the problem of fixing bulk and weak soils, leveling the deformation properties of soils during their water saturation. The technology of injecting the fixing cement-sand solution, closed with a solution of liquid glass, was described on the example of fixing the base under the foundations of a residential building under construction in the floodplain zone of the Taganrog Bay on Kruysa Street.

Keywords: structurally unstable soil, hydrogeological risk, floodplain zone, foundation consolidation, cementation, liquid glass, cement-sand mortar, foundation plate, deformation, ground water

In recent years, studies have begun on the possibility of using anhydrite binders. However, the slow hardening makes it difficult to use this binder for residential and civil construction. The elimination of these difficulties is possible as a result of a deep and comprehensive study of the hardening process of anhydrite binder and the properties of the resulting stone, will make it possible to develop a technology for the manufacture of various building structures based on this binder.

Keywords: Investigation of the properties of a material based on a modified anhydrite binder

The article presents a comparison of architectural and planning solutions of social housing in the USSR, modern Russia and abroad. The socio-economic prerequisites of mass development in our country in different years are briefly considered. General disadvantages of design solutions of old and modern houses are analyzed, such as lack of unique architecture, small variety of layouts and insufficient area of apartments. The purpose of the article is to identify the shortcomings of typical development in domestic construction and to search for redevelopment directions to increase the comfort of small-sized housing, taking into account the individual preferences of residents. The article presents the main possibilities of improving the comfort of inexpensive residential premises. Several areas of redevelopment of small-sized apartments are offered, such as expanding the useful area by changing the purpose of small-used passage zones, redistributing the area by highlighting various functional zones, applying a circular layout and the effects of visual volume increase.Possibilities to increase comfort of small area housing are described: expansion of useful area by transformation of underutilized zones, redistribution of area with allocation of separate functional zones, use of circular layout. In the future, it is proposed to expand the range of unique architectural and planning solutions in modern construction.

Keywords: apartment, small area, redevelopment, housing improvement, planning solution, functional zone, comfort, social housing, affordable housing

The article presents the parameters of the operation of water-jet elevator units, which are widely used in heat supply systems. A new design of a water-jet elevator unit with a pulsed heat transfer medium, adjustable depending on the outside air temperature without using a mixing pump, is proposed. A description of the design and principle of operation of a water-jet elevator unit with a pulsed heat carrier suspension is given. To confirm the effectiveness of the proposed technical solution, laboratory hydraulic tests of the.

Keywords: Elevator, weather control, heating system, controller, pump, valve, sensor, temperature, heat energy, tariff

The design documentation was developed, the layout was made, and an experimental study of the direction-finding receiver was conducted. A functional diagram and a description of the design are given. The method of the experiment is given. Shows the achievement of the following parameters: operating frequency range: centimeter; the dynamic range of the signals at the entrance 48 dB; the duration of the received pulses is not less than 0.1 µs; the irregularity of amplitude-frequency characteristics of not more than 5 dB.

Keywords: direction finding receiver, logarithmic receiver, amplitude-frequency response, amplitude response, dynamic range

The stress-strain state of a two-phase body under the action of a load is described using a system of partial differential equations (Lame equations), the analytical solution of which can be obtained for a narrow class of problems. To apply one of the variational methods to solving the generalized Lamé system, a functional is written based on the potential energy of deformations, which allows us to expand the range of tasks for the study of mechanical processes in soil foundations under engineering structures.

Keywords: two-phase body, water-saturated soil base, potential energy of a two-phase body, stress-strain state

A model of passenger traffic movement is proposed that is suitable for identifying hidden patterns in the processes of passenger flow creation. The passenger flow is divided into four components, for which separate passenger flow submodels are developed: quasi-deterministic passenger flow from leaving stops to points of mass attraction of passengers; stochastic hourly passenger flow from each arrival stop to different districts of the city; stochastic flow that models the distribution of passengers between final stops in accordance with the degree of popularity of stops; chaotic distribution of passenger traffic between stops with a small number of daily visits. The results of calculations of the quasi-deterministic passenger traffic submodel from leaving stops to points of mass passenger attraction are estimated.

Keywords: passenger transport, passenger traffic models, passenger behavior patterns, modeling