Vol 3, No 1 (2004)

Suborbital motion trajectories of an orbit plane when the second stage of a multipurpose air-and-space system is stopped from being placed into orbit are discussed, based on the successive linearization method. The algorithm, forming nominal control, is developed, allowing to calculate controlling functions of the attack angle, the velocity angle of rolling and the thrust which optimize the given criteria, taking into account constraints on control, phase coordinates and motion modes. The character of controlling functions providing maximum lateral range is defined.

The problem of formation of ions of multicomponent plasma and conduction of a film MDM- structure part which is impact-compressed or particle-short-circuited under high–speed impact is solved. Models of plasma-barrier interaction are considered. We obtained analytical equations for multicomponent impact plasma charges and conduction of impact-compressed and short-circuited MDM structure. Ionization-capacitor type detectors of micrometeoroids and technical debris have been developed on the basis of thin MDM structures. Laboratory and space tests have been conducted on the geostationary orbit by «Gorizont-41» and «Gorizont-43» satellites.

The problem of increasing the mission efficiency of a spacecraft with remote sounding of the Earth using optimum distribution of sessions at time intervals is discussed. The problem is treated as one of optimum control of a dynamic system defined by a discrete analog of a Riccati differential equation. A method based on reducing the initial non-linear problem to the equivalent linear one with a larger number of equations is used. The results obtained for both the presence and absence of noise in the motion models are analyzed. The effect of unobservability zones on the result is estimated.

A new numerically-analytical method of solving problems of potential flow about group of two-dimensional bodies is developed. The method is based on the use of conformal mapping of the theory of complex variable function (TCVF) and the method of discrete vortices (MDV). The efficiency of the method is achieved by using the numerical procedure for one body only. The accuracy of the developed method is higher due to analytical fulfillment of zero normal velocity for the central body contour.

Simulation of vascular channel of limbs with regard to artificial gravity caused by a centrifuge with a short effective range is designed. The simulation provides the mode of computational experiment and serves as an instrument for a gravitation therapist. Distribution of inertia head and longitudinal load factor with reference to anthropometric characteristics of patients or phantoms is calculated. Rotational speed of the centrifuge rotor for dose-related load is calculated. Explanations of certain effects of gravitational therapy are given. Further biomechanical problems are formulated.

The influence of chemical composition of ingot bars of different suppliers for the production of gas-turbine engine blades has been studied. The presence of carbon, sulphur, oxygen, nitrogen in the blades and the quality of the items produced were the objects of investigation. The values of the distribution of the total number of metallurgical defects in the blades made of ingot bars supplied by Russian, German and British companies are established. The investigation conducted makes it possible to conclude that it is necessary to check the chemical composition of the ingot bars supplied, including a gas analysis.

On the basis of structural research a mechanism of carbon interphase redistribution during magnetic–impulse working of rapid cutting steel tools is proposed.

The results of investigating vibrational parameters of an elbowed pipeline under force excitation by working fluid pressure pulsations using the finite element method are presented. Various cases of dynamic characteristics of hydraulic chains joined to the outlet section are taken into account. Pipeline vibroacoustic characteristics are shown to depend essentially on the dynamic load of the joined hydraulic subsystem.

A model of an electronic purchase system based on suppliers’ competition is proposed. Its functioning is studied taking as an example one-stage open suppliers’ competition regarding the purchase of products for the needs of the state. The “PARUS Goszakupki” system is given as an example.

The problem of designing reliable real-time control algorithms mounted aboard spacecraft is under consideration. The method of designing control algorithms based on the algorithm semantics model is described which guarantees higher reliability. Data on a computer-aided design system that support the technology mentioned are given.

The paper deals with the factor-coordinated interaction mechanism, which makes it possible to coordinate the interaction between the centre and the active elements. On the one hand, the elements should be interested in fulfilling the plan set by the centre in the basis of the interested of the production economic system as a whole. On the other hand the centre should be interested in factor-coordinated interaction which is achieved by selecting increments of factors essential for the system.

One of the possible educational process structures at higher professional school is considered. It consists of a certain set of psychologically – cognitive and activity levels. The argumentation of each of the levels proposed is given on the basis of which the so-called cognitive-activity educational process matrix is built. The results obtained are supposed to be used to create the phenomenological model of educational material assimilation taking into account both the education background and the motivation factor.

Problems of financing environmental protection measures are considered. The role of the state in the preservation of consumer properties of biosphere as human and manufacturing environment is analyzed.