Tomsk complex for neutron-transmutation doping of silicon

All-Union Scientific-Research Institute of Nuclear Physics at the S. M. Kirov Tomsk Polytechnical University. Translated from Atomnaya énergiya, Vol. 79, No. 1, pp. 38–40, July, 1995.     

Control of complex ecological-economic systems

The paper is devoted to developing methods for control of ecological-economic systems consisting of three hierarchically subordinate subjects of control. In describing the dynamics of a system state, equations in partial derivatives that are solved numerically according to a semi-implicit scheme of the finite-difference method are used. To achieve its main goal (maintenance of an ecological subsystem in stable state), the subject of control of the upper level applies different control methods. Methods of hierarchical control (motivation, enforcement, and persuasion) that differ in the direction of action (on the objective function or domain of admissible controls) are proposed; examples of their use are represented and a comparative analysis of the obtained results is made.     

Use of Intel SGX to ensure the confidentiality of data of cloud users

In this article the problem of possible attacks on confidentiality of user data in cloud systems comes from cloud provider’s side has been investigated. A secure cloud computing system architecture based on Intel Software Guard Extensions technology has been proposed. The approach that provides confidentiality of data of users of cloud systems is given. A method for implementing this approach into existing cloud systems is presented.     

Equilibria in models of hierarchically organized dynamical control systems with regard to sustainable development conditions

We study dynamic game theoretic models for two- and three-level control systems taking into account sustainable development conditions. We consider methods of compulsion and impulsion as hierarchical control methods. We give definitions of equilibria and show algorithms for constructing them in various cases.     

Solution algorithms for differential models of hierarchical control systems

This paper studies a three-level control system. Impulsion serves as hierarchical control at the two levels of the system. We analyze the behavior of the system in the case of informational rules defined by the Germeier games Γ_1t and Γ_2t. Equilibrium design algorithms are proposed. The solution of the three-level differential model is reduced to the exploration of an equivalent multistep-differential model.     

Properties of Dense Assemblies of Magnetic Nanoparticles Promising for Application in Biomedicine

Chemically synthesized iron oxide nanoparticles and magnetosomes produced by magnetotactic bacteria are of great importance for application in biomedicine. In this paper, we discuss the complicated magnetic anisotropy of the nanoparticles, the influence of the magnetostatic interactions, and thermal fluctuations on the behavior of these assemblies. Numerical simulation for dilute assemblies of iron oxide nanoparticles with combined magnetic anisotropy show that the uniaxial shape anisotropy dominates even for small aspect ratios of the particle, L/D≥1.1–1.2. The quasistatic hysteresis loops are calculated for various clusters of bacterial magnetosomes with diameters D=40–60 nm to understand the influence of magnetostatic interactions. The specific absorption rate (SAR) is calculated for assemblies of magnetic nanoparticles dispersed in solid and liquid media. A new electrodynamic method of measurement is used to obtain the SAR of the assembly of bacterial magnetosomes with average diameter D=48 nm.     

Elastohydrodynamic problem for journal sliding bearing under reciprocating motion

A plane elastohydrodynamic problem for a radial sliding bearing with a thin liner under reciprocating motion under a constant load is considered. It has been shown that at the moment of time when the velocity becomes equal to zero the thickness of the lubricating film exceeds zero and that it continues to decrease during a period of time after changing the direction of rotation of the shaft. Film thickness and pressure distributions at various moments in time, as well as time dependences of the eccentricity and the minimum film thickness along the spatial coordinate, are presented for various values of the dimensionless parameter, which depends on the period of reciprocating motion. It has been shown that the smallest value of film thickness over the entire period of reciprocating motion increases with shortening period of reciprocating motion.