Vol 52, No 2 (2016)

This paper describes the control of computations in a distributed computing environment (DCE) on the basis of its meta-monitoring and simulation modeling. Computations are controlled by a multiagent system with a given organizational structure. Resource allocation is carried out by agents with the use of economic mechanisms for controlling their supply and demand. Controlling actions for agents are formed on the basis of the simulation modeling of functional processes of the DCE. Data about the DCE resources and processes are collected and emergency situations in the DCE nodes are detected and prevented by the meta-monitoring system of this environment. The research results are the techniques for selecting control actions and the methods for intellectual processing and effective storage of data.

A novel approach is proposed for solving probability problems arising in studying reliability of readout of random point structures. The essence of this approach is based on combining specialized program-analytical and discrete-combinatorial methods of research seldom used in academic practice. The efficiency of the proposed approach is demonstrated by an example of solving a particular problem that involves two-threshold readout of random point images.

This paper describes the problem of passive identification of heat equation coefficients with account for the noise of the behavior of the object dynamics model and for the noise of the measuring system model. The use of the finite difference method allowed for reducing the solution of partial differential equations to the solution of a system of linear finite-difference and algebraic equations described by models in the form of a state space. Presentation of the heat equation in form of such a model makes it possible to apply the Kalman filter algorithm for the reliable estimation of the behavior of the object under study.

The kinetics of mirrors with saturable absorption is investigated by a pump-probe singlefrequency technique in reflection of femtosecond pulse radiation with the central wavelength of 1040 nm. The double modulation method with probe radiation detection at the summary frequency allows suppressing the scattered pump radiation contribution and reaching the reflection change sensitivity at a level of 10⁻⁵. The kinetics of recovery of the linear reflectivity of the mirror including resonant quantum wells with nanostructured barriers is studied for the surface density of photons in pump pulses of (0.3–5.8) · 10¹⁴ cm⁻². The time of electron-hole recombination (7.8 ps) is found to be appreciably shorter than in samples with quantum wells separated by thick barriers; the time of ionization of excitons localized in quantum wells (0.2–0.4 ps) increases with the pump intensity.

The interaction of a cold vortex ring with flame in an axisymmetric configuration has been investigated using methods of Hilbert optics, shearing interferometry, and numerical simulation. The impact of a cold vortex ring formed by a pressure pulse from the annular area surrounding the source on the flame has been numerically simulated. The modes of breakup of the flame structure, blow-off, and quenching under various conditions of vortex ring formation were identified. It is shown that in the case of both complete and partial quenching, most of the flame is blown off. However, in the case of incomplete quenching of the flame, in its lower part there is a small combustion zone, which then grows back to the previous size.

The transformation of zero-order Bessel beams to a second-order Bessel vortex beam in a c-cut CaCO₃ crystal has been studied experimentally. It has been shown that it is possible to control the beam transformation in the crystal during heating. The influence of the thermo-optic effect and the linear thermal expansion of the crystal on the transformation of the Bessel beam is explained.

The architecture, composition, specific features of operation, and technical characteristics of an automated control system of the Large Solar Vacuum Telescope of the Baikal astrophysical observatory are considered. The system is used for automation of both the observation process (automatic telescope guiding to the Sun, selection of a needed region in the solar disk image, guiding based on prescribed coordinates, and video monitoring of the basic subsystems of the telescope) and the auxiliary operations (evacuation, siderostat mirror unloading, and dome control).

Mosaic focal plane arrays (MFPAs) have been designed, and a number of addressing schemes reducing the blind zone have been proposed. A precision technology for fabricating MFPAs with a total size of the blind zone of not more than 30 μm has been developed. Certain systemic issues of applying MFPAs are discussed. The designed 3072 × 576 uncooled microbolometer MFPAs based on 384 × 288 submodules with a pixel pitch of 17–51 μm provide ∼99% image conversion efficiency in the infrared range and those with a pixel pitch of 100 μm provide 100% image conversion efficiency in the terahertz range.