Optoelectronics, Instrumentation and Data Processing (v.44, #2)

An approach to simplifying the calculation of efficiency indices of distributed computer system functioning is described. The approach makes it possible to derive, in terms of uniform methodology, equations for calculating probabilities of states as well as moments (initial and central) of arbitrary order for system transient functioning. Results of numerical analyzing the functioning efficiency of massively parallel processing computer systems are presented.

The errors of quadrature signal interpolation are analyzed. Quantitative assessment of the noise effect and the quadrature signal distortion is given. A method for estimating the accuracy of quadrature output sensors is proposed.

Three-dimensional inspection of grid spacers of fuel assemblies of nuclear reactors using diffractive optical elements by P. S. Zavyalov; Yu. A. Lemeshko; L. V. Finogenov; Yu. V. Chugui (111-117).
The method for inspecting grid spacers (GSs) using diffractive optical elements is considered. Synthesis of diffractive elements, calculation of projecting optics, and also adjustment and calibration of the measurement system are presented. Methods for processing images obtained on different GS elements are described.

Selective diagnostics of multiflame burning using simulation by S. M. Borzov; S. T. Vaskov; O. I. Potaturkin; Zh. O. Sheishenov (118-124).
A problem of tongue-selective diagnostics of the burning process in multiburner research and industrial installations is considered. The main factors that govern the response of optical sensors and gas analyzers to changing processes in the chamber as a result of fuel redistribution are determined. A simulation model of the object investigated is created. The model takes into account the determined dependences. A tongue-selective combustion diagnostics algorithm based on the developed model is proposed and demonstrated.

Results of applying domain engineering technologies to the development of distributed measurement systems are reviewed. An ontology of the subject domain “network measurement objects” is presented. A generalized core architecture of distributed measurement systems developed with aspect-oriented design methods is described.

A new optical method for measuring sizes of a dispersed phase (gas bubbles in liquid or drops of liquid in gas) illuminated by a laser “sheet” is substantiated theoretically and experimentally. The accuracy of the method is determined by the resolution of image recording systems. In a test experiment, the error for measuring the sizes of a dispersed phase was under 1%.

A problem of optimal assignment of parallel program branches to processor cores of a distributed computer system (CS) in order to minimize its execution times is formulated. The formulation takes into account the hierarchic organization of the distributed CS communication network, the property of multicore processors, and the structure of a parallel program information graph. Stochastic sequential and parallel algorithms for solving the problem are proposed. Results of algorithm modeling by a cluster CS are presented.

A structure of hardware-software universal time provisioning in a seismic-acoustic system for rock mass geomechanical monitoring is described. The structure was tested at a mine in the Chitinskaya Region. A measure of inaccuracy of universal time counting is analyzed and calculated.

Results of thorough program synthetic aperture modeling intended for clearing up the influence of some interferences on the quality of synthesis, in particular, the additive noise and yaw of a vehicle with hydrophones as most significant ones, are described. It is proposed to compensate for the impact of vehicle yaw on the quality of synthesis by additive correction of the yaw angle by the criterion of maximizing the quality of the peak characterizing the observed pin-point object.

Gradient design of refractive surfaces for forming required light distributions by A. A. Belousov; L. L. Doskolovich; S. I. Kharitonov (161-168).
A method for designing refractive surfaces for forming required light distributions from compact light sources is developed. Calculation of the refractive surface is based on gradient minimization of the error function representing the difference between the calculated and required illumination fields. The method is based on surface representation via the eikonal light field distribution in the adjacent plane. The eikonal function is defined as a polynomial. An analytical expression for the error function gradient is obtained. Refractive surfaces for forming rectangular and triangular light distributions are calculated.

The hue of two-layer objects with volume diffuse light scattering by O. L. Golovkov; E. I. Chernov (169-172).
It is found that the hue of two-layer objects with the volume diffuse light scattering depends on the angle of light incidence and the top layer thickness of the object.

Metal-dielectric filters in transmitted light by N. D. Goldina (173-177).
A two-cavity metal-dielectric structure with four very thin silver layers is described. The structure is calculated within the scope of two models: a homogeneous layer and a conducting surface. The silver film parameters were measured experimentally. It is shown that results of calculating the spectral transmission of the filter with the experimentally measured parameters differ drastically from calculations with optical constants of bulk samples.

An interrogation technique for fiber Bragg grating sensors based on optical time-domain reflectometry by Yu. N. Kulchin; O. B. Vitrik; A. V. Dyshlyuk; A. M. Shalagin; S. A. Babin; A. A. Vlasov (178-182).
A method for fiber Bragg grating (FBG) interrogation is proposed. The method rests on measuring the light intensity reflected from FBG sensors by means of a standard optical time-domain reflectometer. Multiple FBGs along the fiber optic line are interrogated through time division multiplexing. Specifications of FBGs enabling linear response of the sensors to strain and temperature are determined. The threshold sensitivity to strain is 0.8 · 10−4; the threshold sensitivity to temperature is 5°C.

The influence of the residual birefringence in optical windows on the results of ellipsometric measurements is considered. The optical properties of the windows are described by a complex relative transmittance. Corrections to the ellipsometric parameters, which arise in measuring on static ellipsometers, are calculated under the assumption of weak window anisotropy in a linear approximation. Analysis of the obtained relationships shows that the corrections are partly averaged in two-zone measurements. It is found that the optimal position of the windows corresponds to orientation of their optic axes at an angle of 45° relative to the light incidence plane.