Generation of K-Shell Radiation of Noble Gases in the Microsecond Implosion Regime

Russian Physics Journal - Studies of K-shell plasma radiation sources were performed on the GIT-12 generator (4.7 MA, 1.7 μs). In the experiments, a new type of load configuration was used to...     

Superstabilization of linear dynamic plants under operator disturbances

We consider the state stabilization problem for a linear stationary plant whose parameters and dynamic order can change jumpwise in the course of operation, which leads to changes in its mathematical model. We assume that the set of all possible mathematical models corresponding to the plant is finite. To solve this problem, we suggest to use the simultaneous superstabilization method and the dynamic order extension method.     

Estimating the instability radii of polynomials of arbitrary degree

We consider the determination of the instability radius of polynomials. Sufficient conditions are stated for robust instability of a family of polynomials. A lower bound on the instability radius is given in the general case and the exact value of the instability radius is obtained for polynomials of fifth degree. The proof relies on the geometric properties of continuous curves in a plane combined with parametric properties of the roots of a family of polynomials and the apparatus of the Tsypkin-Polyak hodograph. Applications of the results are illustrated. __________ Translated from Nelineinaya Dinamika i Upravlenie, No. 4, pp. 127–134, 2004.     

Simultaneous stabilization of plants of various orders

We consider the problem of constructing a common controller stabilizing a finite family of linear dynamic plants of various orders with respect to state. For the solution, we use the method of extension of dynamic order, which permits one to reduce the original problem to a problem of simultaneous stabilization of plants of the same order. We state conditions for the existence of a universal stabilizer for a given finite family of dynamic plants.     

Features of rubber swelling in transformer oil,according to NMR data

NMR spectroscopy, NMR relaxation, and NMR with a pulsed magnetic field gradient methods are used to study the swelling of the elastomers based on ethylene-propylene rubber, butadiene-nitrile rubber, and fluororubber SKF-26 in transformer oil. Components corresponding to the fractions of oil and polymer network are identified. It is shown that the affinity of the polymers toward transformer oil displays an increase in the orderly sequence of ethylene-propylene rubber, fluororubber, and butadiene-nitrile rubber; the stability of the polymers towards carbon tetrachloride falls in the same sequence. Based on an analysis of the spin–spin relaxation time depending on the degree of swelling, it is found that fluororubber elastomers are characterized by the formation of a polymer network that prevents further sorption, In contrast, elastomer based on ethylene-propylene rubber gives no indication of the formation of a rigid polymer network.     

Stabilization of switched linear systems by a controller of variable structure

We study the state stabilization problem for switched linear systems operating under parametric uncertainty and bounded coordinate disturbances. To solve the problem, we suggest an algorithmfor constructing a controller of variable structure on the basis of methods of simultaneous stabilization theory.     

On some approaches to the simultaneous stabilization of linear plants by a controller of a given structure

In the present paper, we consider the problem of simultaneous stabilization of linear scalar stationary plants of arbitrary order for which we obtain numerically verifiable necessary conditions for simultaneous stabilization and a sufficient condition with the indication of a constructive algorithm for synthesizing a stabilizing controller. We also consider the problem of extending the set of simultaneously stabilized plants. For the solution of these problems, we use an approach based on the analysis of the structure of stability domains in the spaces of coefficients of polynomials linearly depending on parameters.     

Simultaneous stabilization: Construction of a universal stabilizer for linear plants with delay with the use of spectral reducibility

We consider the problem of the construction of a common stabilizing controller for a family of k linear stationary nth-order plants with commensurable delays in the controls and the state variables. Our approach to stabilization is based on the construction of a common two-loop stabilizer. The controller of the first (internal) loop solves the problem of reducing each plant of the family to a finite spectrum, and the controller of the second (external) contour solves the stabilization problem.