Vol 17, No 1 (2013)

The boundary control problem for the system of hyperbolic equations with the mixed derivative is considered.The control is provided by the displacement (in the conditions of the first boundary-value problem).The coefficient matrices of different structure are explored for the system.The commutativity of these coefficients is the essential condition.If the matrices couldn't be brought to the diagonal form simultaneously,it's offered to use special differential operators for representation of the necessary problems solutions.

The first boundary value problem was considered for the second order loaded differential equation of mixed elliptic-hyperbolic type in a rectangular region. The local and nonlocal problems for the loaded partial differential equations of the individual and mixed types have been previously studied in areas where the hyperbolic part is the characteristic triangle. In this work, in contrast to the well-known ones, necessary and sufficient conditions of the uniqueness of this problem solution were found by the method of spectral analysis.

The work contains the survey of results related to the study of near the boundary behavior of the solution of the Dirichlet problem with the boundary function in $L_p,$ $p > 1$ for a second-order elliptic equation. There are new statements and some unsolved problems in this direction.

This work is devoted to some class of parabolic equations of high order with double nonlinearity which can be represented by a model equation \begin{gather*} \frac{\partial}{\partial t}(|u|^{k-2}u)= \sum_{\alpha=1}^n(-1)^{m_\alpha-1}\frac{\partial^{m_\alpha}}{\partial x_\alpha^{m_\alpha}} [|\frac{\partial^{m_\alpha} u}{\partial x_\alpha^{m_\alpha}}|^{p_\alpha-2} \frac{\partial^{m_\alpha} u}{\partial x_\alpha^{m_\alpha}}],m_1,\ldots, m_n\in \mathbb{N},\quad p_n\geq \ldots \geq p_1>k,\quad k>1. \end{gather*} For the solution of the first mixed problem in a cylindrical domain $ D=(0,\infty)$ $\times\Omega, \;\Omega\subset \mathbb{R}_n,$ $n\geq 2,$ with homogeneous Dirichlet boundary condition and finite initial function the highest rate of decay established as $t \to \infty$. Earlier upper estimates were obtained by the authors for anisotropic equation of the second order and prove their accuracy.

In the paper we show a survey of results related to the existence of boundary values of solutions of elliptic equations.

The boundary value problem with data given on the parallel characteristics for the system of hyperbolic equations with the wave operator and the singular matrix coefficient at the lower derivative is considered in the characteristic square. This system of differential equations in the characteristic coordinates can be reduced to the system of Euler–Poisson–Darboux equations. Using the known solution of Cauchy problem with data given on the singularity line of matrix coefficient, we reduce the problem to the Carleman system of integral equations.The explicit solution of the considered boundary value problem is constructed using the results of previous research on the solvability of the systems of generalized Abel integral equations, made by the author.

In this work we study the effect of time finiteness of the existence of Cauchy problem for nonlinear Schrödinger equation solution. Together with the ill-posed Cauchy problem we consider its neighborhood in the space of operators, representing Cauchy problem. We explore the convergence of sequence of solutions of Cauchy problems with the operators, approximating the initial Hamiltonian.

The work is devoted to the investigation of some classes of nonlinear integral equations of Hammerstein–Nemitski type with noncompact operators. Above mentioned class of equations, beside the theoretical interest has immediately an application in kinetic theory of gases. The existence theorems for positive solutions in different functional spaces are proved.

The feature of solution formation of boundary valueproblems is considered in plane strain of ideal rigid-plastic bodywhen the plasticity condition is related with level lines ofstrain states surface of work-hardening incompressiblerigid-plastic body.

The technics for the construction of approximate analytical solutions for the quasistatic problems of thermoelasticity (plane-stressed state, plane deformation) for the multilayered bodies with variable within limits of each layer physical properties of medium. The recursive method is used for the construction of systems of coordinate functions, satisfying the boundary matching conditions, given as the equality of radial (normal) stresses and displacements in the layer-contact points.

The problem of curvilinear fibers rationalreinforcement for axially symmetric ring-shaped lamel in polarcoordinate system is solved by reference to the structural model.The effect of structural parameters for a construction limitstressing is studied.

The paper analyzes the effect that the material of a simple rheological beam has on thedynamics of a moving disc. The hybrid system of the differential equations describing the motion of the systemdisc–rheological beam consisting of the integro-differential equation of beam longitudinal vibrationsand the Lagrange equations of the first kind, defining the motion of the disc, and the equationsof nonholonomic constraints following from the difference between the Lagrange coordinates of thedisc mass center and the beam point contacting with the disc is composed. The paper considersthe mode of the disc steady motion, allowing to integrate the equation of beam vibrations regardlessthe system of equations describing the motion of the disc. It is identified that when the disc movesat a low speed, and in the mode corresponding to the limit value of the relaxation time it causes physically inadequate strain in the beam. When relaxation time is null there is a steady mode of forced beamvibrations at moderate amplitudes.

N. N. Bogolyubov discovered microscopic solutions of the Boltzmann–Enskog equation in kinetic theory of hard spheres. These solutions have the form of sums of the delta-functions and correspond to the exact microscopic dynamics. However, this was done at the “physical level” of rigour. In particular, Bogolyubov did not discuss the products of generalized functions in the collision integral. Here we give a rigorous sense to microscopic solutions by use of regularization. Also, starting from the Vlasov equaton, we obtain new kinetic equations for a hard sphere gas.

The axisymmetric non-stationary problem of electroelasticity for a solid piezoceramic axially polarised cylinder is considered under the kinematic load in the form of well-known mechanical displacements of its face surfaces, as well as the electric potential. The new closed solution is constructed by vector eigenfunction decomposition method in the form of structural algorithm of finite transformations. The obtained calculation relationships allow analyzing the influence of the external circuit characteristics on the form and sizes of the induced electric pulse in nonstationary problems of direct piezoeffect.

In 1989, Ohya propose a new concept, so-called Information Dynamics (ID), to investigate complex systems according to two kinds of view points. One is the dynamics of state change and another is measure of complexity. In ID, two complexities $ C^{S} $ and $ T^{S} $ are introduced. $ C^{S} $ is a measure for complexity of system itself, and $ T^{S} $ is a measure for dynamical change of states, which is called a transmitted complexity. An example of these complexities of ID is entropy for information transmission processes. The study of complexity is strongly related to the study of entropy theory for classical and quantum systems. The quantum entropy was introduced by von Neumann around 1932, which describes the amount of information of the quantum state itself. It was extended by Ohya for C*-systems before CNT entropy. The quantum relative entropy was first defined by Umegaki for $ \sigma $-finite von Neumann algebras, which was extended by Araki and Uhlmann for general von Neumann algebras and *-algebras, respectively. By introducing a new notion, the so-called compound state, in 1983 Ohya succeeded to formulate the mutual entropy in a complete quantum mechanical system (i.e., input state, output state and channel are all quantum mechanical) describing the amount of information correctly transmitted through the quantum channel. In this paper, we briefly review the entropic complexities for classical and quantum systems. We introduce some complexities by means of entropy functionals in order to treat the transmission processes consistently. We apply the general frames of quantum communication to the Gaussian communication processes. Finally, we discuss about a construction of compound states including quantum correlations.

The solution of the eigenvalue problem for non interacting electrons of the quantum ring in the magnetic field is discussed. The potential shape of the quantum ring permitting analytical solution was proposed. The solution of the appropriate eigenvalue problem was found in the terms of the Heun functions and expression for the energy levels was obtained. It was pointed out that proposed potential might be considered as a single-well or double-well potential of concentric quantum rings.

The evolution scenario of the resource distribution in the fractal-cluster systems which are identified as organism on Burdakov's classification is suggested. In this model the resource distribution dynamics is determined by the ultrametric structure of the fractal-cluster space. Thus for each cluster there is the characteristic time of its transition to an equilibrium state defined by ultrametric size of the cluster. The general equation that describes that dynamics is presented. The numeric solution for that equation for the certain types of resource transformation between clusters is received. The problem of identification of parameters of model with reference to real systems is discussed.

Electromagnetic field in classical and quantum mechanics is naturally representedby geometry of extended phase space, with extra coordinates of time and canonically conjugate momentum$p_0=-E$.

The article gives an algorithm for constructing quantum integrals of motion on the basis of well-known classic integrals.To construct quantum integrals, we apply star product of the operators' symbols, which is used in the quantization theory.A non-trivial example of the Klein–Fock equation is considered on the four-dimensional Lie group.