Methods and tutorials
The development of aerospace has always been one of the priorities of the Russian Federation government. Clearly, the process of staffing and providing with highly-skilled professionals in aerospace should be continuous and efficient. Currently, the majority of leading Russian enterprises develops and trains their human resources beforehand, choosing among the most talented students from industry-specific schools. Target preparation for aerospace is the guarantee of enterprise and sector development.
Among the clients are aerospace enterprises which form individual courses of target training, then monitor the realization of the courses and choose the most promising students. The further work in the chain «School-University-Science-Enterprise» implies a cyclic training and as a result we get qualified and experienced specialists.
The specialists of the Resource Center of Scientific Research and Innovative Technologies (RC NSIIT) MAI (NIU) have been working for a long time in the sphere of training highly-qualified specialists in aerospace sector. As a result of their work they developed and introduced a comprehensive online tool of remote users cooperation (The patent #_126492 d.d. November 16, 2012 for a complex system of distant learning and videoconferencing ).
Application of this complex system is determined by a complete delivery in a duplex mode video and audio materials, lectures, diagrams, presentations, text and video files, 3D-images with the opportunity to create video archives and to conduct simultaneous online classes. It makes the learning process effective due to the quality and efficiency of delivering necessary studying materials and due to the presence effect.
This complex system contains specialized server software, interactive block, information site and the blocks of users and listeners. Each of the blocks has an architecture which is necessary for solving the tasks of distant learning and videoconferencing in the most optimal modes. In this complex system the changing of the configuration is possible due to the connecting additional components that allows expanding the range of operational capabilities of the system. The system enables the general integration of various components into one technical solution, development of one information space and the possibility to connect users to it, expansion of operational capabilities, optimization of conducting video conferences and higher rates of system performance in the context of more distant users and minimal requirements to the Internet channel and equipment.
Using innovative technologies in the process of training, the possibility of distant «live» communication of two and more users provide a new level of specialists training and the quality and efficiency of obtained knowledge.
Keywords: aerospace industry, target training, specialized software, distance learning, innovation technologies
Mathematics. Physics. Mechanics
There is the reliable determination of vibrational stresses characteristics in aeronautical product structure during the operation of aviation products along with a plane-carrier topical problem. These characteristics are needed to evaluate the strength and durability performances of the aeronautical product and for an estimation of operating possibility with the more rigid modes of flight. Experimental study of the problem with the use of full-scale prototype or physical models has a significant labour input and cost.
In the present work the technique for numerical simulation and researches results for Aeronautical product random vibrations characteristics calculated by the given technique is presented. For simulation of aeronautical product dynamic stress state the system of solid-state simulation and finite element calculation for complex structure Solid Works is used.
Numerical models and calculated estimation of Aeronautical product random vibration characteristics in the conditions of joint flight with the carrier are presented. The accepted vibrational effect on an aeronautical product corresponds to the real flight loadings and is simulated by the specifying spectral density of accelerations in the knots of a suspension point of an aeronautical product.
Spectral density and variance distribution of stresses in various points of a structure are constructed at structure excitation by random stationary processes. Maximum stresses levels zones for the aeronautical products located on an external suspension bracket of the maneuverable carrier are defined.
To construct random functions, which describe the change of dynamic stresses in time, it is used the statistical modeling algorithms of stochastic processes. Implementations of random functions with the current time value are modeled as the harmonic series with random parameters. Stochastic functions implementations at each current value of the time are modeled in the form of harmonic series with random parameters. The implementations of random processes of stresses, which correspond to dependencies for spectral densities of the stresses, are obtained.
The ordinates of the obtained stress process model have the distribution closer to normal. On the basis of conformity between implementations of processes model and initial spectral density of stresses the levels of stresses are estimated. Random stress processes with the use of standard algorithms of «rainflow» are led to an equivalent set of damaging action of pressure regular cycles. The presented graphs are the probable density of the amplitudes for the resulted regular cycles of stress.
The developed numerical models of the forced random oscillations can be used for an estimation of vibration strength of aviation product under operating conditions.
The work is executed with the RFBR financial support (the project № 13-08-01243-а).
Keywords: aviation product, structure, forced random oscillations, finite element method, dynamic state, vibrational stress, stationary vibration, spectral density, statistical simulation
The Couette-Taylor flow in compressible gas is of great importance in theoretical physics as well as for technical applications. There is a variety of research papers on the flow in incompressible gases and liquids considering both theoretical issues and numerical simulation results. However, the number of studies for the compressible flow is limited, despite its increasing applications. The purpose of this paper is to obtain numerical results for the Couette-Taylor flow in compressible gas using the software ANSYS CFX to study the vortex structure within one symmetric couple and the effect of the cylinder surface temperature as well as Reynolds number on the vortex structure and vortex density.
In order to produce reliable results for unlimited coaxial cylinders, the physical model was built to guarantee the length of the cylinders is much bigger than the gap between the two cylinders (100 times in our model). To obtain compressibility properties, air was chosen. The numerical results showed symmetric trajectories of air particles in neighboring vortices, which means the vortices are coupled and each couple contains two symmetric vortices.
The vortex density as well as the vortex structure were studied through the Reynolds number and the cylinder surface temperature. The Reynolds number based on the speed of the inner cylinder changes within the range of 4.104 and 4.105. The temperature is referred to the stagnation temperature. The results show similar dependencies of vortex density on the Reynolds number and on the surface temperature. The density initially increases with the increase of the Reynolds number. After reaching its high, the density drops dramatically before remaining stable despite the increase of Reynolds number.
The same pattern is observed for vortex density and temperature relation. In our model, the surface temperature of the inner cylinder was fixed and the surface temperature of the outside cylinder was changed between one to eight with respect to the stagnation temperature. The vortex density remains unchanged when the surface temperature of the outside cylinder exceeds seven.
Keywords: Couette-Taylor flow, compressibility influence, flow structure
Local stress fields concentrated near the interfaces of layered composite materials and excited by thermal loads are investigated on the groundwork of the gradient thermoelasticity theory. The new model of gradient thermal conductivity for layered composites is proposed to analytically describe the thermal barrier properties of not modeled interfaces by the classical heat conductivity theory. The barrier effect modeling becomes possible due to the raised order of the equations of the gradient thermoelasticity and heat conductivity models as compared with the classical ones, so that the boundary conditions of new types can be formulated. The proposed model allows one to define both deformations and normal stresses on the interfaces of composite structures subjected to thermal loads.
The new model is used to formulate the one-dimensional problem of the gradient thermoelasticity and heat conductivity for the layered structure as a boundary value problem for the system of linear ordinary differential equations with constant coefficients, therefore the analytical solution on the basis of the elementary functions becomes possible, so that allows one to perform the qualitative and quantitative analysis of the barrier effects to the stress state and strength of the composite structure.
The five-layer one-dimensional structure loaded by the temperature field is considered as a test example. The formulation of the boundary value problem is shown and the physical meaning of the boundary conditions of the new type provided by the gradient model is briefly discussed. An analytical solution is obtained. It is shown that the small scale factor results the boundary layer type of the solution with high-amplitude stress peaks concentrated at the boundary points. These effects cannot be described by the classical thermoelasticity model even in the 3D problem formulation. It may be supposed that these stress peaks can result also the known effect of cracking on the composite interfaces discussed in many modern publications.
Therefore the proposed model can become a versatile and efficient way to compute the stress state of heat-loaded composite materials, and it can be used for the composite structures design in engineering practice.
Keywords: gradient theory of elasticity, thermoelasticity, layered composites, stress-strain state, thermo-barrier properties of interfaces
Object: the object of the research is dynamic characteristics of the rectangular plate.
Topic: study of shock interaction during the vertical incidence of a rectangular plate made from homogeneous isotropic material on the liquid.
Aim: to verify the numerical model of interaction between rectangular plate with the water surface. To investigate the influence of different factors on the dynamic characteristics of a rectangular plate with a vertical drop on the liquid.
Research method: dynamic characteristics of a rectangular symmetric plate numerically investigated in the software complex ANSYS AUTODYN, while the resolvent equations are the equations of conservation of energy, momentum and mass. In general, materials have a complex response for the dynamic loading. In ANSYS AUTODYN model of the material is divided into three parts: the equation of state, which expresses the change in the volume, model of strength, which expresses the change in the shape and describes the stress deviator tensor, and the failure model. The solution is carried out by explicit solver. The task is formulated in the plate symmetric coherent formulation, i.e. equations for plates and liquid are simultaneously solved. The influence of the air gap and initial velocity on the plate dynamic characteristics is investigated. The obtained results are processed in software complex Mathcad 14.
Results: the dynamic characteristics of rectangular plate made from homogeneous isotropic material vertically dropped on the water with different initial velocity of interaction are obtained as a result of the work taking into account the gravitational forces and presents or absence of air gap.
Conclusions: The adequate simulation of cargo drop on the water is possible in the software complex ANSYS AUTODYN. From the numerical experiment without the air gap it is shows that hydrostatic pressure is linearly depend on the initial speed. The effect of air gap causes oscillation of the plate and water surface, which leads to their inequal interaction and significantly affects the value of the maximal pressure, however, with the increasing speed of interaction effect of air gap is reduced.
Keywords: impact, rectangle plat, interaction with liquid, numerical simulation
The equations which describe the strain waves by means of asymptotic methods for solving the hydro-elastic problem that includes the dynamic equations of three coaxial geometrically nonlinear elastic shells are obtained. Energy dissipation and equations for an incompressible viscous fluid between cylindrical shells with appropriate boundary conditions are taken into account. We obtained equations, which generalize the well-known Korteweg-de Vries equations by introducing the term describing the liquid impact between the shells. The radius of the medial surface of the shell is significantly smaller than the wavelength of deformation, and therefore the asymptotic transition to the classical equation of hydrodynamic lubrication theory is made in the equations of viscous incompressible fluid.
This paper describes the numerical solution to the Cauchy problem for the resulting system of new equation with the influence of the fluid. This approach to the construction of the difference scheme is based on the construction of the predetermined system of differential equations, derived from the integral approximation of conservation laws and the integral relations, connecting the unknown functions and their derivatives. As a result, the difference scheme is defined as a condition for the compatibility for the system and the resulting difference scheme automatically ensures the fulfillment of the integral conservation laws in the areas, made of the basic finite volumes.
The presence of fluid between the co-axial shells gives rise to deformation waves not only in the outer shell but also in the inner ones, where the initial deformation moment is equal to zero. Hence, the deformation wave of stable amplitude and velocity takes place. This fact is in accordance with the solitary wave solution, which cannot be described analytically. The construction under consideration can be characterized as a five layered packet with liquid as a filler.
Consequently, the use of these models allows for a widening of experimental data analysis possibilities in the course of the investigating various systems — fuel supply, cooling for aerospace engineering and etc., which dynamics is principally non-linear.
Keywords: non-linear waves, coaxial cylinder shells, incompressible liquid, soliton
The paper discusses the current issue on methodological support of fragmentation testing, analysis of existing theoretical and experimental methods of obtaining data on the characteristics of fragmentation fields. The analysis shows the need to improve reliability of the source data for fragmentation, increasing the information value of existing ammunition test methods, as well as automating of the process of collecting and processing of the raw data obtained.
To eliminate the shortcomings the method of determining the parameters of the fields of remote fragmentation munitions is proposed, which can be implemented if testing system consists of a control unit to undermine two spaced noncontact sensors, n — units of measurement, analog-to-digital converter, a memory unit, transmitting and receiving devices, computers. The main advantage is the use of testing complex proximity sensors consisting of a set of sectors made in the form placed perpendicular to the lines of photo detectors and emitters.
The simulation of the process of fragment separation allows to produce functional testing of the system for the automated collection and processing of the data on the characteristics of the fission field, and calculate the effect of the initial data received to change the law of the coordinate target defeats of targets under specified conditions.
Thus, the proposed method of testing aircraft weapons will provide: the definition of the main characteristics of fragmentation fields as distribution of the fragments by mass, speed and direction of separation, increasing the reliability of such parameters as the ballistic performance, form factor and the initial velocity of the fragments; obtain some information on the nature of separation flow projections; automation of data collection and processing.
Keywords: tests, fragmentation field, ammunition, the method of calculating
Presented article is devoted to structure realization of thermionic thermal protection of the multiple unit scheme with a characteristic size of thermionic elements about 1-10 mm. There is a technique for calculation and numerical estimations of thermal protection operation performances during the aerodynamic heating of hypersonic aircraft structure units in the temperatures ranges from 1500K to 2100K. It is shown, that thermal flows of electronic cooling can make an essential contribution into the balance of thermal flows on the forward edge of hypersonic aircraft wing, protected with the help of multiple unit thermionic thermal protection during the flight, because thermal streams of electronic cooling can reach size in 1.5MW/m2 and above, that is directly confirmed by known experimental data about thermionic transformation. The maximum temperature of structure elements with multiple unit thermionic thermal protection is lees then radiation and equilibrium temperature in a point of the maximum thermal streams by a 600K.
The received results can be used during the development and creation of hypersonic aircraft of various types and purposes at the stage of detailed and technical design.
Keywords: thermionic issue, electronic cooling, electric energy, hypersonic aircraft; thermal protection
The calculation method of suboptimal spacecraft paths of space vehicle is elaborated in the powered flight phases to the earth satellite orbits during the engine thrust vector control. The problem of one-stage-space vehicle ascent is considered for the vertical and horizontal launches. The maximum of spacecraft finite mass is used as an optimality criterion which is equivalent to the providing minimum fuel consumption. The restrictions of maximum admissible overload values and velocity head are considered.
The method consists in the conditional partition of spacecraft path into specific areas: vertical take-off, gravity turn, generation of terminal conditions. In each area the rational control programs are determined and the obtained results are conjugated. As a result the task of control functions search comes to iteration task of parameterization of a number of varying parameters. After the determination of first approximation parameters, with which the spacecraft injection to the specified orbit is provided, the successive variations of each parameter are specified in order to provide the local maximums of spacecraft finite mass. The iteration process is over when the variation of any one of the parameters doesn’t result in the improvement of optimality criteria. Application of this method allows to avoid the complex calculation procedures used for calculation of optimal paths by classic methods. There are presented the results of elaborated method approbation for calculation of the ascent trajectories in the wide range of change of boundary conditions, mass, power and design, and ballistic parameters of spacecraft.
The new injection scenario of spacecraft to satellite orbit is proposed. It consists in the preliminary shaping of an interim orbit with the apogee altitude less than the specified one and the further two-impulse orbit correction. The high efficiency of the proposed scenario is shown. The fuel mass gain as compared with the traditional spacecraft injection scenario for the considered variation ranges of initial data is ~ 3,0 — 3,5 tons for the vertical takeoff and 2,5 — 3,0 tons for the horizontal takeoff.
The developed method can be the basis for the developed adaptive board algorithms which allow to correct the control program depending on the values of current parameters of spacecraft motion.
Keywords: spacecraft, suboptimal control, powered phase, satellite orbits, maximization of finite mass, velocity head, overload, specific flight phases
The paper concerns the power-limited spacecraft trajectory optimization in parametrical space of Kustaanheimo-Stiefel (KS) variables. There are shortly discussed the KS-variables and their main properties. The problem of optimal control is formulated as a problem with mixed constraints (equality constraints on functions of the control and state variables), which follow from the bilinear relationship and it is solved using the Pontryagin’s maximum principle.
The boundary-value problem is solved using the continuation (homotopic) method. Parameterization of the boundary value problem is presented which eliminates the need in bilinear relationship. The parameterization extends a set of admissible controls to trajectories without analogues in the physical space at the start of continuation procedure.
There is presented the numerical example showing some qualitative features of the KS-transformation such as the conformality and mapping of the physical point into a circle in the KS-space. The latter leads to the correspondence of trajectory in the physical space to the family of trajectories in the KS-space.
As an example, the problem of fixed-time transfer between fixed points of non-coplanar circular orbits is solved. There are presented trajectories both satisfying and not satisfying the bilinear relationship. Geometry of trajectories in the physical space is presented.
If an arc of initial circular orbit is assumed as an initial approximation of transfer trajectory, the use of KS-variables does not lead to the growth of computational consumptions in comparison to using the Cartesian coordinates with the same precision. In case of problems with large inclination change, the KS-variables provide better convergence in comparison with Cartesian coordinates.
Keywords: Kustaanheimo-Stiefel transformation, power-limited problem, continuation (homotopic) method
While studying operation of radio frequency ion thrusters, it is necessary to analyze its output beam parameters. A computerized diagnostic system was developed for this purpose comprising: probes for the determination of local plasma parameters inside the beam; three-dimensional coordinate mechanism for probes transportation; software and hardware control unit for the coordinate mechanism and for the collection and initial procession of test data. Faraday cup probe was used for the diagnostics of charged particles current inside the beam, as well as for the ion beam profile determination. Angular divergence of the ion beam was used to define thrust losses. Retarding potential analyzer was used for the ion energy determination. That helped us to define thrust losses in view of the known densities of charged particles of different types. The ExB filter was developed to determine densities of multiply charged ions. Charged particles separation in the crossed electric and magnetic fields was provided by such filter. Determination of the electric field distribution in the beam is rather interesting, because it allows calculation for the charged particle motion in the beam.
The diagnostic system was developed on the basis of the laboratory at the Electric Propulsion and Space Power Plants Department of the Moscow Aviation Institute.
Keywords: radio-frequency ion thruster, beam diagnostic system, probes
Control and navigation systems
In this paper, the design parameters of four-beam acceleration sensor based on optical tunnelling effect are considered and that the errors analyses of this sensor to get more accurate sensing of acceleration for passenger aircrafts is conducted. For the acceleration measurement, a sensor, based on optical tunnelling effect, with the «prism-total internal reflection-plate», can be designed. The sensing element is designed with quartz, and basic sensing element consists of light emitting diode, prism, four-beam element, photodiode and processing block. The transfer function of this acceleration sensor is determined by the output optical power and the output voltage, dependent on the magnitude of the deflection element and sensing gap. Under the influence of acceleration, the deflection of sensing element depends on the length, thickness and width of the sensing element as well as the additional mass, installed in the centre of the element. Moreover, the effects of angle of incidence light, initial gap of sensing element and the effect of temperature are also significant. The effect of the deflection of sensing element due to above mentioned factors is considered. Such acceleration sensor can be used under actual conditions, e.g., as a part of control systems on an aircraft, or inertial navigation systems. This sensor should be used in cases when reducing size and weight, the ability to operate in explosive and hazardous environments are critical. Due to quartz high temperature resistance capability, it can maintain its characteristics in different temperature zones that are typical for aircraft.
Keywords: sensor, acceleration, four-beam sensing element, tunnelling, prism, temperature, reflectivity, errors
On-board cables of flying vehicles due to their significant length are the most sensitive receptors on exposure to EMI.
Electromagnetic interferences immunity of on-board systems of flying vehicles depends on shielding efficiency of the on-board cables, which evaluated from parameters of the cable shields. The shielding efficiency related with important characteristic of cable shields — coupling impedance (transfer impedance).
Therefore, it is important to provide required shielding efficiency of on-board cables. For this purpose it is necessary on design stage to evaluate the levels of the conductive electromagnetic interferences in inner conductors of the on-board cables, generated by different electromagnetic influences.
The accuracy of evaluation depends on choice of a coupling impedance model. Comparison of known models of coupling impedance of the on-board cables of various types of flying vehicles is the problem that was studied in the paper.
A theoretical part is based on classical electrodynamics and electrical engineering. Also elements of the complex variable theory and operational calculus were used.
The paper presents results of evaluation of on-board cable coupling impedance frequency characteristics, executed with MATLAB. On the basis of results presented a conclusion can be made that accuracy of evaluation depends on model of coupling impedance selection.
The present paper provides a part of research in calculation electromagnetic interferences on-board cables of space vehicles.
Keywords: on-board cable, flying vehicle, electromagnetic interference, coupling impedance
Technical cybernetics. Information technology. Computer facilities
Expert systems are used to solve complex practical problems in different spheres of human activity. Methods and data mining algorithms are widely used to create knowledge-bases for expert systems. However, this mechanism often generates thousands of rules, which makes it difficult for experts to analyze and interpret data, and also makes knowledge-base rules excessive and very often conflicting with each other.
In order to improve the efficiency of expert systems’ usage, it is necessary to combine similar rules. This optimization is performed by structuring the data and minimizing the amount of rules without losing data completeness.
The search for similar rules is performed for rules with identical values of consequents. That is why we need to divide sets of the rules into disjoint subsets.
Let’s consider the fuzzy-production rule represented as the Takagi-Sugeno mode. We will proceed from the fuzzy sets to their quantitative value using a defuzzification procedure. This procedure uses the method of gravity center. Then we need to normalize all the values obtained. The resulting system of vectors can be used as points in the high dimensional Euclidean space. Our task is limited to solve the problem of taxonomy of these points. I chose the k-means algorithms to solve this task.
In the issue of a knowledge-base optimization, the criteria of optimal work can be the generalization error obtained by the expert system during the work on a selection of test data. The minimum value of the generalization error corresponds to the optimal cluster solution.
A series of experiments have been made to confirm a prior assumption of increasing effectiveness. For testing purposes random sets of data have been selected as «spam» and regular mail messages.
Series of experiments show that the classification accuracy of the system using optimized knowledge-base has improved in comparison with the initial results. Consequently, optimization of the knowledge-base has improved generalization capability of the expert system during the work with test set of data.
Keywords: knowledge-base, expert system, reduction of fuzzy rules, knowledge-base optimization in expert systems
Radio engineering. Electronics. Telecommunication systems
The article deals with electronic control devices computer-aided system design procedure. These devices are meant to work as a component part of the control circuit of high-precision electric drives based on contactless torque motors.
The article shows that implementation of both classical synthesis of of control loop components transfer characteristics by automatic control theory, as well as engineering method of control devices design, for example, proportional-integral-derivative controller (PID controller) using Ziegler-Nichols method, Chien-Hrones-Reswick (CHR) method or other, require the knowledge of transfer characteristics of all actuator components: motor, feedback sensors, all components of the transmission mechanism, control units, that can be obtained either experimentally, by theoretical calculation or as result of simulation. This procedure is based on using similar models — electric circuits and electromechanical analogies either for electronic control devices, or for electric motor, transmission mechanism, angular position sensors and load.
Source options for structural diagram of electric drive are standard circuit control devices. Electronic devices modeling system OrCAD-PSpice is used as a modeling tool, which allows to automatically obtaining Bode plot and transfer characteristics of the motor and the transmission mechanism. Then control device parameters are determined by formal methods for each option.
Selection of optimal control device is performed according to the results obtained from the joint modeling of all actuator components also by means of PSpice. In this case it is possible not only to obtain frequency response and transient characteristics of actuator, but also simulate the functioning of the actuator during input disturbances, close to real operating modes.
The proposed methodic allows:
— to use well-known software products for modeling electronic devices such as OrCAD-PSpice as means of simulation of all components;
— to automate calculation of transfer characteristics of all components of the following-up system in time domain, as well as in frequency domain, using PSpice built-in features;
— to automate calculation of the set of functional characteristics of all following-up system components in whole as well as its intermediate parts by means of the possibility of integration of similar parts models into electric motor drive integrated models and using a common simulation tool;
— to use PSpice parametric optimization subsystem software package for automation performance enhancement of components, synthesized by known formal methods, in order to obtain a higher accuracy of actuator characteristics, performance, and energy efficiency;
— to perform direct modeling of actuators and electronic devices, containing nonlinear and parametric components and, therefore, of control devices with variable parameters in operation, as well as to perform parametric optimization;
— to use the vast set electronic components libraries available in standard PSpice-OrCAD complex to create new models of electronic control devices, and other actuator components.
Keywords: electronic control devices, contactless motor, design, optimization
In this paper, characteristics of onboard laser ranging system of space vehicles are investigated with using of mathematical modeling methods. The selected model is the classical equation model of laser ranging based on the geometrical optics approximation. The numerical method of spectral density is based on Planck’s law for black body.
The developed software called «MITRA» is designed to assess the feasibility of pulse laser ranging systems at work on space objects having a diffusely reflecting surface and equipped with corner reflectors. «MITRA» makes possible to evaluate compliance with the requirements of laser safety in the spectral range from 0.81 to 1.54 μm, to investigate the influence of the laser beam divergence at measurement distance on diffusely reflected signal, to measure the influence of back ground illumination on measurement distance on the diffusely reflected signal and corner reflectors. All the simulation is performed under an assumption that the power of background noise significantly exceeds the power of its own thermal noise of the photo detector.
It was obtained that the usage of corner reflectors enables measurements in the range from 20 to 55 km without laser pulses could exceed the limit defined laser safety standards. Use the so called safe wavelength 1.54 μm can increase the beamwidth of a laser, which in turn reduces the need for guidance and retention laser beam on the object. The simulation results show that the program «MITRA» can be recommended for wide use in early design prototyping.
Keywords: laser ranging system, space vehicles, rendezvous and docking, modeling, program
In this work it’s introduced the research results of interrelation between the electromagnetic radiation (EMR) reflection and transmission characteristics of shields with a flat and geometrically inhomogeneous surface shapes based on composite perlite containing materials and their surface temperature is studied. The dynamics of surface temperature specified EMR shields ranging from —18 °C to +18° C is obtained. It’s established that the EMR reflection coefficients values of these at their surface temperature +18 °C are
—4...—25 dB and EMR transmission coefficients values are —5...—27 dB in the frequency range 0,7...17 GHz. It’s shown that reduce of surface temperature of the studied EMR shields from +18 °C to —18 °C leads to the decreasing of their EMR reflection coefficients the values on 3...7 dB (for the shields with a flat surface shape) and 2...10 dB (for the shields with a pyramidal surface shape) with increasing EMR transmission coefficients values on 5...9 dB in the frequency range 0,7...13 GHz ( for shields with a flat surface shape) and 0,7...6 GHz (for shields with a pyramidal surface shape). Surface temperature of investigated EMR shields with a flat surface shape does not affect to the EMR reflection and transmission coefficients values in the frequency range of 13...17 GHz and shields with the pyramidal surface shape — in the frequency range of 6...17 GHz. It’s proposed to use the investigated EMR shields for the manufacture of protective housings equipment used in unheated areas, and composite materials used for their formation — for walls facing of shaded buildings.
Keywords: gypsum, reflection coefficient, transmission coefficient, perlite, calcium chloride, electro-magnetic radiation
Economics and management
Low level of equipment and decrease of airdromes and airports, which are the clue elements of civil aviation system along with the air companies and air-traffic management organizations.
Method or methodology of analysis
During the analysis of problem we have collected, summarized and structured the information as well as supplied it with the author’s and expert’s opinion, conclusions and remarks.
Results of analysis
The condition of land infrastructure of small aviation airports is highly unbalanced nowadays. On the one hand there is a serious run-out of basic productions assets, on the other hand there is low level of provision of airports by technical buildings and constructions.
Regional airdromes have the lowest level of provision by technical units nowadays. Their land production base is in condition that doesn’t correspond nor to future neither mostly often to current needs of transportation process. The majority of regional and local airports are in critical condition, part of them has ceased their operation activities.
The airports and airdromes which have ceased their operation activities in the last few years aren’t being used even as alternate airfields.
One of main reasons for such situation around the land base is insufficient investment in maintenance and development of airports. The number of objects financed by the federal budget hasn’t increased in the last years and has remained at the level from 35 to 40 objects.
The main volumes of passengers- and cargo- carrying operations are concentrated in 12 biggest hub airports which don’t allow to fully use the transportation potential of the country.
According to the concept, by the end of 2020 the airdrome network must include more than 500 airports, mainly due to development of regional air-transporting infrastructure.
The airdrome network of Russia must consist of three groups of airports: federal, regional and local airports.
The group of federal airports must include the airports of high social and economic importance for Russia in general, the biggest units of concentration of regional and inter-regional flow as regards the hub airports (for example, Moscow, Krasnodar, Saint-Petersburg, Khabarovsk, Novosibirsk, Yekaterinburg, Ufa, Mineralnye Vody).
Regional airports must carry out transportation services between the federal regions of Russia (located in the administrative centers of regions).
The group of local airports must include the airports carrying out transportation services within one region of Russia.
Local airports must be not exceptional but normal for the majority of Russian citizens. The distance between them must not exceed 300 km — by example of American regulations.
The current condition of airdrome network is not able to carry out in full amount and with necessary quality its basic functions in favor of the country and its citizens, it doesn’t promote normal development of aviation business and national security of the Russian Federation.
The problem of development of local and regional transportations is especially crucial in the regions with low level of land transport infrastructure. Failure to take effective measures may lead to irreversible termination of activities by air companies carrying out local and regional transportations, which may lead in its turn to severe social and economical consequences in the regions.
Keywords: airdromes, airports, civil aviation, regional transportation
Formation of profitability ratios of R & D in the aviation industry from the federal budget is currently one of the most urgent scientific problems in the aviation industry. Methodological approach to the formation of basic standards of profitability should be developed taking into account the rational combination between budgetary and extra-budgetary funds and the necessity for stabilization of organization financial position in view of aviation industry as the release profile and non-core products.
Profitability of R & D, as well as the profitability of the entire scientific and technical products, in principle, can be determined by agreement between an Executing agency and Government customer with the baseline profitability standard for the Executing party and changes that depends on the economic, socio- economic and other efficiency of produced products, its technical, economic and operational characteristics scientific and technical level in the whole, extent of economic risks of performer and Government customers, as well as other conditions under the R & D contract (agreement).
To calculate the basic profitability standards is advisable to consider the following indicators for the planning and reporting years: total activity of the company, including R & D performed only by Federal Targeted Programme (FTP); the total amount of company internal activities (excluding the cost of purchased raw materials, components and special equipment purchased from outside, as well as payment for the loan, etc.) with internal R & D performed by FTP; taxes, fees and charges attributable to the company financial results. It should be noted that earlier for Russian R & D defense industry was a tax exemption on VAT from all sources of financing R & D. In 2004-2005 it was unfortunately removed. This has increased the complexity of R & D funding, especially in terms of extra budgetary funds in aviation industry.
In order to stabilize the financial situation of aviation scientific organizations it is proposed to create initially equal conditions for them: set the same percentage of profit remaining at their disposal by Government customers (for example in terms of percentage of the cost of internal activities).
Keywords: aviation complex, R & D funding, the aviation industry, profitability
Purpose: to develop a new approach to the formation of a set of integrated marketing communications. The article shows the system model of quality management, market research and public relations interrelation in social marketing of services. In order to analyze the customer perceived quality parameters and to measure satisfaction with these parameters, fixing «breaks» between satisfaction and value of each of these indicators to the customers, the article shows what quality settings are «visible» to the client. To develop a methodology of satisfaction measurement with medical care, the theory of service quality by A. Parasuraman, V. Zeythaml and L. Barry has been adapted to the specific medical services.
Based on analysis of a comprehensive marketing program «Dialogue with the patient» the author shows the integration of public relations with marketing research, which revealed the use of a unified communication (marketing research) to achieve several goals at once — receive marketing information for management decisions, strengthen customer relationships , and also to find new customers on the recommendation of existing customers. It goes beyond the standard application of public relations for the reports of marketing research results to a wider audience, demonstrating a kind of symbiosis in which marketing research use is not one-sided. The article brings new understanding that marketing research is the marketing communication, which allows to build a dialogue, the value of which is higher than just getting information of the recipient.
The article opens a new view on the role of marketing research in the integrated marketing as an independent interlocutory marketing communication evidence from healthcare marketing.In social marketing, it allows to select marketing communications not only based on the characteristics of the industry, company, product and market, but also to the extent that the communication is dialogic, with priority on bilateral marketing communications: PR and marketing research. One of the factors that should be taken into account, is the power of dialogic communication in building long-term relationships with the public. This is especially important in social marketing, which is used to achieve social goals on the basis of dialogue with the public.
Keywords: quality management, integrated marketing communications, public relations, marketing research, social marketing, services marketing