2010. № 39

In this article the matter concerning the evaluation of the speech information protection against unsanctioned access is considered and some conditions are defined for which the information safety appears to be sufficient.

Keywords: threshold signals; information protection

Proposed architecture of a system, built on technology .NET Remoting using Reed-Solomon codes to ensure safe delivery UDP-packets. The use of Reed-Solomon codes is intended to improve the efficiency of applications, using the protocol UDP.

Keywords: Reed-Solomon codes, UDP, stack TCP/IP, distributed client-server application

The paper describes pressing question of modeling of the telecommunication traffic. Authors present a simple numerical methods of parameters calculation for well known traffic models M/G/ Input and On-Off Sources, which allows to simulate both self-similar properties and some statistical characterizes.

Keywords: self-similar traffic; traffic simulation; M/G/∞ Input and On-Off Sources; heavy-tailed distribution

In this article the materials are given for optimizing the structure and the parameters of the initial orientation of the navigation systems in the azimuth. The algorithms are obtained for optimal nonlinear filtration under conditions of Gaussovoy approximation posteriori density of the probability. The filtrate equations can be simplified if the pulses amplitude is given and it is taken the possibility of SNS at short distances with the chosen power of the useful signal into consideration. Then it is not difficult to obtain the equations solution for the second central moments after temporary average. It is given the schedule of the errors dispersion of the useful signal filtration (the messages).

Keywords: optimizing the structure and the parameters; gaussovoy approximation; the navigation systems; the errors filtration

Investigation of unsteady disturbance in cascade, received by cylindrical surface separation of model fun blade row, is developed. Flows in cascade on choke mode and stall mode are investigated. Stationary and oscillating cross-sections are used in computations. Necessity of Flow – structure interference accounting is shown. Rotating stall initiation condition are received.

Keywords: unsteady disturbance; compressor cascade; flow vibration; cross-section vibration; rotating stall

Main principles of a choice of parametres and feature of designing of system of film cooling of a profile part of a feather of working shovels of high-temperature turbines GTE are considered at high sizes gas temperatures 1650К <(Т ^*) _gas <1850 … 1900К for сопловым the turbine device on an input in the driving wheel. The expediency of orientation of channels of protecting cooling at an angle to a turbine axis is revealed, is close to a radial direction. In this case discrete streams of individual channels form a uniform protecting veil and their thermal efficiency becomes comparable to the system of cooling consisting of separate cracks. Also possibilities of economy of the expense of the cooling air spent for cooling of blades of the driving wheel of the turbine are investigated. With that end in view, various sites of a feather on shovel height, and also its bent and выпуклою the parties, it is necessary to cool differentially, in conformity with available distribution of temperature of gas to a profile part of a feather of a blade and level of non-uniformity radial distribution diagram gas temperatures on an input in the turbine.

Keywords: airfoil; blade; cascade; rotor; heat-transfer; film-cooling; design; stage; rib

We calculated the trajectory of motion of bodies falling to Earth from deep space by the example of spherical meteor. Calculations are performed for different impact parameters, the velocity at infinity and the different sizes of bodies. To calculate the drag force and heat flux during the motion of bodies in the atmosphere using the new dependence on the Reynolds number, constructed on the basis of self-similar interpolation. The possibility of destruction of meteors from the forces of pressure and heat in the atmosphere.

Keywords: equations of motion; the dependence of the resistance areas and heat flux on the Reynolds number; self-similar interpolation

The methodical approach developed by authors and algorithm of the decision of a problem of a choice of a power mode of behaviour of the mesh heaters used for imitation of external thermal loadings on elements of an external surface of a space vehicle is stated. Efficiency of the given approach on an example of the decision of modelling problems is illustrated.

Keywords: imitation, thermal loadings, a space vehicle, a mesh heater

This paper contains research of the staffing problems faced by the enterprises of aviation and aerospace industry. The results of “Evaluation of specialists’ training quality and their professional advancement” monitoring are given. Some practical ways out of the situation in the enterprises are outlined.

Keywords: staffing problems; results of monitoring; demand for specialists

The article analyses a problem of Russian industrial enterprises obsolescence and considers means of equipment renewal financing, including leasing. The evaluation system of cooperation efficiency between an industrial enterprise and a leasing company was developed by the author.

Keywords: obsolescence, renewal of equipment, amortization, leasing

The article explored sources of the state normative requirements in sphere Occupational Safety and Health (OSH): Constitution Russian Federation, federal laws, resolutions Government Russian Federation. The main positions politicians are considered of the OSH and organizations production on enterprise.
The conceptual model of the formation the duty regulations will presented with provision for state normative requirements of the OSH.

Keywords: occupational safety and health; social-economic indexes; normative-legal base

Abstract The mathematical model of the sliding liquid bearing is presented. The model allows heat transfer throw bearing case and bush with ambient. Dependencies bearing load capacity from materials thermal conductivity, eccentricity and rotation speed are presented.

Keywords: sliding bearing, liquid lubrication, heat transfer, load capacity, lubrication layer temperature

Urgency and problem of increasing efficiency of a piston internal combustion engine by recycling of heat of the exhaust gases are considered in this article. Classification of modes of recycling of heat of the exhaust gases is spent. Prospective advantages of direct injection of water are defined. Patent search of decisions for direct injection of water is spent. Result of patent search is classification of modes of direct injection of water (steam) and choice of the most perspective decisions. The current state of problem and most important questions demanding decisions are defined.

Keywords: internal combustion engine cycle; direct injection of water; recycling of heat

We consider the asymptotic behavior of controllable mechanical generic system with linear non-holonomic constraints in a vicinity of the submanifold where the rank of of the system of the constraint equation falls down by one.
We show that if the control parameters are the generalized forces bounded by some constant, then the attainability domain for arbitrary initial point does not contain the neighbourhood of this submanifold. On the other hand, the control kinematic system determined by the same constraint equations is completely controllable.
An example of a system with degeneration of linear constraints is considered. The system consists of a heavy beam with two attached sleighs.

Keywords: control mechanical system; degeneration of non-holonomic constraints; slow fast variables

In this paper generalized Hermite functions are considered, recurrent expressions of its derivatives and primitives are obtained. Calculating algorithms of spectral characteristics for multiplication, differentiation, and integration operators are formulated. They are approved on a number of examples (including functional approximation, approximation of derivatives and primitives, analysis of linear deterministic control systems).

Keywords: basis, Hermite polynomials; Hermite functions; spectral method; spectral characteristic

Choice problem arise during the design and creation of modern rocket and space technology, for comparative analysis of technical means, as well as decision making in terms of managing non-standard aircraft.
In this paper we propose an algorithm for aggregating expert estimates, given the strict preference. Aggregation of preference relation reflects the individual preferences of experts and does not contain any circuits. The method is based on the construction of a loaded majority graph. The algorithm containes an original procedure, the destruction of contours.

Keywords: decision making, group selection, majority graph, preference relation, ranking, aggregated preference, Hamming distance, coefficients experts

A statistical method for simulating a boundary layer transition flow is proposed as based on experimental data on the kinematics and dynamics of turbulent spots (Emmons spots) on a flat plate placed in an incompressible fluid. The method determines intermittency with allowance for overlapping spots, which makes it possible to determine the forces on the plate surface and the flow field near the transition region if the mean streamwise velocity field in a developed turbulent boundary layer is known as a function of the Reynolds number. In contrast to multiparameter transition models, this approach avoids the use of nonphysical parameter values.

Keywords: boundary layer; laminar-turbulent transition; statistical simulation

The article presents basic specifications to the aviation launching equipment construction on the life cycle stages with considering of technical exploitation on condition. Main problems of the life cycle stages and possible solutions of the problems in considering of technical exploitation on condition of the aviation launching equipment construction are offered.

Keywords: aviation launching equipment; exploitation; damage; operating period

Keywords: software modeling; interaction graph; CASE