2001. № 3
Aviation technics and technology | |
In the given article the process of filling of parachute systems is investigated. The experimental relation between the effective area of parachute resistance and filling time is received. The results of the solution of motion equations system "freight - parachute" show good convergence with the experimental data. Keywords: |
|
Economics and management | |
This work concerns the actual problem of applying mathematical methods in manufacturing process control. We examine the problem of optimal workplace scheduling that lies at the core of operative control systems for flow-line and batch production. At present, heuristic methods are applied for practical solution of this problem since, due to a number of its features, precision methods degenerate into the exhaustive search of variants. In this work a new method for the solution of the problem has been proposed. It is a hybrid computing procedure that applies, in order to accelerate the convergence of exact branch and bound method, the technique of searching the local-optimum solution of combinatorial problems at definite steps of the branch and bound algorithm. Keywords: |
|
Mathematics. Physics. Mechanics | |
We are lonely because the Universe is bad for live. It is more probable to observe a universe in which life is a rare phenomenon. Keywords: |
|
Rest mass took the place of inert mass in modern physics textbooks. It seems to be wrong. This topic was considered by the author in the article [1, 2]. Additional arguments to a confirmation of such a thesis are presented here. Keywords: |
|
A deep attitude to logic paradoxes, as Zeno's paradoxes, B. Russell's paradox, points to an imbecility of members of the species Homo Sapiens. The author intends to pay attention to a weakness of world-wide logic paradoxes and hereby to reject attempts to discredit logic. Keywords: |
|
Contrary to a standard opinion, it is affirmed that circular polarized plane electromagnetic waves carry a spin angular momentum. A field of a rotating electrical dipole is considered. An unusual covariant form of electrodynamics is used, the form represents a self-dependent interest. A reason of the elimination of the electrodynamics spin tensor is found out. A concrete nonzero expression for an electromagnetic wave spin tensor density is suggested, and a virtue of this expression is demonstrated at an example of absorption of circular polarized electromagnetic waves. Keywords: |
|
The analysis and generalization of design and experimental researches of local mode of deformation and strength for plates and shells with nonthrough damage, having various geometry, are presented. It is shown, that the most effective way of desgn determination of local stress and strains in a nonthrough damage zone with an entering angle is the using of a finite element method and certain simulation technology. On the volumetrical high dimensionality finit elements base numerical models of plates with various mode nonthrough damages are developed. The models allow to evaluate stresses and local deflection maximums, influence of nonthrough damadge sawing on stress concentration value and, as result, to diminish of damages danger. Keywords: |
|
Radio engineering. Electronics. Telecommunication systems | |
In this article the possibility of underlying surface simulation for radar-tracking systems is esteemed on the basis of the information on the same surface obtained in optical range. The simulation was carried out in a reference system conterminous to a reference system of the map in optical range, where the direction of the bearer coincides attitude of the optical map, that has allowed to receive the pattern of the underlying surface map in a radio-frequency range with maximal fidelity with other things being equal. The results of raster maps simulation are reduced at different lateral angles of deflection of the antenna directional diagram of the bearer radar-tracking system. The median filtering is esteemed as preprocessing the map for its consequent analysis. Keywords: |
|
The novelty and complexity of systems of a cellular communication based on technologies of Code Division Multiple Access (CDMA), requires some ordering of their functions. Especially in view of the large number of the publications printed in Russia for last years. In the given work the designation, structure and principles of shaping of channels in a system of a cellular communication of the standard IS-95 is considered. Keywords: |