Vol 8, No 3-4 (2014)

The authors consider two methods of solving a system of two functional equations defining the mathematical model of the contact problem for an elastic layer, taking into account the friction forces in the contact area. The first method is based on replacing the system of functional equations by paired system of linear algebraic equations. The second is based on the orthogonalization of systems of functions. The numerical solution of the problem is also shown in the article.

Based on the analysis of a hysteresis loop (circular diagram), three areas were highlighted which characterize the different behavior of the stresses, i.e. three types of stress are revealed. For each type of stress corresponding evolution equations are formulated which describe the anisotropic hardening. To describe the isotropic hardening the author introduces an evolution equation for the fourth type stresses. A stress deviator is defined as the sum of the stresses of four types. To describe the non-linear process of stress accumulation there is introduced a kinetic damage equation, based on the energy principle where the energy consumed to create damage in material considers as energy equal to the work of the second type stresses on the total strain space. The material functions are shown, the basic experiment and the method of identification of material functions are formulated.

The article provides an overview of existing methods of combating a clutter considering modern domestic and foreign sources. The authors examined the methods of combating a clutter in transmission path, antenna path, and intermediate frequency path as well as in blocks of primary and secondary radar data processing. The paper presents statistical and spectral methods.

The author suggests a variant of the linear theory of thin plates, based on the assumption that the integral equations of dynamic equilibrium can be written for any volume in the undeformed state. Rigorous study of these equations, after the introduction of the concepts of kinematically equivalent displacements, are separated initial-boundary problems of stress-strain and bending. The attention is focused on the problem of bending. A theorem on the uniqueness of the solution is proved. Examples of test problems of bending, natural oscillations and panel flutter are given. A substantial dependence on the Poisson's ratio is revealed.

The article discusses the features of the application of coherent accumulation in passive radar systems, operating on signals of telecommunication sources. A technique for coherent accumulation is developed. Factors limiting signals time accumulation are discussed. The dependences of range of the system and signal/noise ratio of the received signal from accumulation time are shown. The conclusions about the effectiveness of coherent accumulation in passive radar systems are made.

The paper presents several algorithms for identification, describing complex objects or control system, including: an algorithm for identification of linear time-varying control systems, multi-row algorithm for decision-making by the method of group record of arguments and neuropackage to solve the problem of functions approximation