Home – Home – Jornals – Avtometriya 2016 number 3

An algorithm is proposed for estimating the coordinates of nodes of deformed lattices of quasi-periodic textures without preliminary detection of typical texture elements. Examples are provided to demonstrate high computational efficiency of the algorithm on the basis of real halftone images containing quasi-periodic textures.

A wavelet in the form of the first odd wave prolate spheroidal function is proposed for the wavelet transform of a non-uniform 2 D image and the formation of clusters of wavelet coefficients on it. Methods for calculating the wavelet function, clustering the field of wavelet coefficients, and constructing their corresponding optimal rectangular windows in the image are described. The high efficiency of the methods and the algorithm implementing them under various real operating conditions of the optoelectronic device has been shown by modeling studies

The problem of classification of multispectral space images of forest vegetation is considered. Features based on the wavelet transform and a classification method involving consideration of the significance of each feature are investigated. Dependence of the classification results on the wavelet function, the level of transformation, and the parameter of the classification method - the number of segments of the range of features - is given. Results of classification of multispectral images of six classes of forest vegetation in images obtained by a Rapid Eye shooting system are presented.

This paper presents a comparison of the capabilities of natural and artificial intelligences in problems of identifying operators of information-processing systems and their functional state based on the features of writing handwritten passwords. The cause of the significant spread in the subject identification error probability as determined. It is concluded that at the present level of knowledge, the best result achieved in solving the problem by artificial intelligence systems is close to that potentially possible. It is demonstrated that the use of features of reproducing handwritten passwords is suitable for recognizing the functional state of operators of human-machine systems in professional activities.

A new type of polarization signatures is proposed for estimating the anisotropy of spatial inhomogeneities of the Earth cover with the use of space polarimetric radar images. The case of radar imaging of a pine forest in a decimeter band of wavelengths at different azimuthal angles is considered

This paper discusses the features of training simulation for solving problems of visual and instrumental observation and monitoring of the Earth from the Russian Segment of the International Space Station (ISS). Approaches satisfying the requirement of real-time mapping of the digital visual Earth model with a resolution of up to 15 m/texel with viewing angles of 2 to 110° in a simulation of ISS flight are described. A solution allowing simulation of camera observations using a positioning system is presented. The characteristics of the developed software and hardware are given.

The problem of reconstruction of the sound speed profile in the water column in a shallow-sa waveguide by means of geoacoustic inversion from single-hydrophone recording of a pulse signal is considered. A method for solving this problem with the use of high-performance computer systems is developed and implemented. Numerical experiments performed by using this algorithm show that the sound speed profile in the water column can be reconstructed on the basis of some very rough estimates for geoacoustic parameters of the bottom. The use of tehse rough estimates does not affect the accuracy of sound speed profile reconstruction provided that the signal spectrum containg some components of sufficiently high frequency.

This paper presents a method for initializing fuzzy Takagi-Sugeno systems in which the initial values of fuzzy antecedents are obtained by dynamic decomposition of the input space, and consequent values by the recursive least squares method. The results of experiments on 13 datasets from the KEEL repository are described. Comparisons with the results of their approximation by five known identification algorithm are given.

This paper considers the inclusion of a cascade compensator in the forward path of designed systems according to the Smith predictor scheme, which is an effective way to solve two problems: achieving the desired performance of the system processes and placing the dead-time element outside the closed loop, so that its effect is only manifested in an increase in the transient time by the delay value and does not affect the overshoot value. It is shown that the Smith predictor scheme should be used with caution because, being an additive signal compensation scheme, it may be not robust and require accurate knowledge of delay values for its robust implementation. The problem of sensitivity analysis of the processes in the system to time-delay variation is stated and solved.

A method of real-time reconstruction of the useful signal and its lower derivatives on the basis of a recurrent smoothing spline is presented. A calculation technique for a spline with the number of measurements at each segment greater than the number of nodes is given, and the spline coefficients are found by the variational approach.

The process of nucleation of 2D islands near a monatomic step at the initial stage of growing of a silicon film on the Si(111)-(7 x 7) surface is studied by means of in situ superhighvacuum reflection electron microscopy. The dependence of the depletion region width W near the step, where no islands are formed, on the deposition rate R is described by the expression W² ∞ R^-χ with the exponent χ = 1,18 and χ = 0,63 at temperatures of 650 and 680 °C, respectively. It is demonstrated that the change in χ is associated with the step structure, which ensures the transformation from the growth kinetics limited by embedding of adatoms into the step to that limited by diffusion of adatoms. A competition of the processes of nucleation and embedding into the step leads to an increase in the size of the critical particle nucleus from i = 1 far from the step to i = 3-5 near the step and to i = 6-8 on the terrace of critical width for 2D nucleation.

Proximity effects in formation of photonic crystals in the form of ordered arrays of holes of similar radii close to 100 nm by methods of electron beam lithography are considered. The coefficients of the proximity function characterizing the contribution of back-scattered and secondary electrons to the exposure doze are experimentally determined. It is demonstrated that the minimum standard deviation from the mean radius of the elements in the array is provided by means of correcting the proximity effect with the use of experimentally obtained coefficients and an iterative equation with an increased contribution of back-scattered electrons.

This paper describes the selection of inhibiting films made of aluminum of various thicknesses (300-500 nm) and intended for inhibiting electrons (with an energy of tens of kilo-electron-volts to tens of electron volts) in the developed new generation picosecond dissectors. The designed dissectors should be different by a high time resolution as compared to the one maximum reached ( 20 ps) in LI-602 dissecting electron-optical converters used to diagnose synchrotron radiation. The comparative measurements of emission characteristics of manufactured films in the models of electron-optical converters similar in design to a PIF-01/S1 device taken as a basis for the dissectors and providing the maximum time resolution of up to 1 ps in the mode of single linear sweep with the sweep velocity of 10¹⁰ cm/s. It is established that, with the incident electron beam energy equal to 10-12 keV, the optimum thickness of the inhibiting aluminum film is 400 nm for the effective secondary emission coefficient of 0.7.

This paper describes a new electron-optical dissector based on a PIF-01 chronographic electron-optical device developed and manufactured at the Prokhorov General Physics Institute of the Russian Academy of Sciences (PGPI RAS). The results of the static measurements of the instrumental function of the dissector, which show that its time resolution can be higher than 4 ps are given. These data are confirmed by direct measurements on the bench of the PGPI RAS with the use of a femtosecond titanium-sapphire laser.

This paper describes a fiber-optic transmission system for access networks with frequency division of channels formed in optical, microwave, and radio frequency ranges. The single-band optical modulation and different formats of modulation of subcarrier channels are studied. The calculated expressions for estimating the number of spectral and subcarrier channels in view of the effect of stimulated Raman scattering (Raman effect) and optical preamplifier noise are presented