Home – Home – Jornals – Avtometriya 2005 number 3

A new algorithm for constructing the regularized solution of integral equation of the first kind with a difference kernel is proposed. It is shown that the algorithm allows one to take into account various a priori information on the desired solution (non-negativity, increase, decrease, etc.) and that usage of the discrete Fourier transform and the fast Fourier transform algorithm substantially decreases (by 2

Examples of quite simple functions that have the properties of finiteness, boundedness, and non-negativity, and their Fourier transforms have no zeros anywhere are presented. It is proposed to use these functions for proper apodization of primary image detectors in order to fulfill the necessary condition of functioning an imaging system with a priori given spatial resolution.

Presentation of quaternion signals describing spatial group point objects in their own coordinate system is considered. Rotation- and scale-invariant structural features of the pattern given by the quaternion signals are introduced. The problem of recognizing quaternion signals presented in their own coordinate system, which does not require preliminary signal overlapping, is solved.

An algorithm for correcting dynamic errors in broadband signal recorders with parallel channels is proposed and analyzed. The algorithm is based on measurement of the channel synchronization errors by means of an amplitude-phase Fourier transform and correction of the samples by interpolation. Results of numerical computer modeling of the algorithm accuracy, depending on the noise level, the signal frequency, and the synchronization errors, are presented.

It is proposed to simulate fluid flows in the three-dimensional space by a three- dimensional cellular automaton model. A series of experiments to compare simulation results with analytical calculations is presented. Relationships between model and physical parameters are derived.

The problem of highly realistic image synthesis is discussed. A technique for specifying three-dimensional clouds bounded by freeform surfaces is considered. A fast semi-transparent object rendering algorithm is proposed. A method for simulating an inhomogeneity while visualizing atmospheric effects is presented.

Problems concerned with modeling profiled silicon diaphragms as sensitive elements of amplitude fiber-optic pressure sensors are considered. The simplified model error is estimated. A version of describing the sensitivity of a microreflector in fiber-optic sensors as a function of rigid center width is proposed.

A numerical algorithm for constructing virtual X-ray projections for trajectories that do not satisfy the Kirillov-Tuy conditions (incomplete trajectories) is proposed.

Methods for obtaining of tomographic projections and reconstruction of the spatial- spectral structure of polychromatic objects with different dimensions are considered. It is demonstrated that while obtaining projections in the multidimensional phase space, one can apply nonconventional tomographic reconstruction algorithms.

The field effect is examined in a  superconducting film, which is a component of a ferroelectric (PZT)

Principles of designing silicon multiplexers for line and array infrared photodetectors are considered. A unified series of 13 multiplexers designed for joint operation with multielement photodiode MCT photodetectors, multielement photoresistive photode- tectors based on multilayer structures with quantum wells, and with other types of photodetectors with spectral sensitivity in IR ranges of 8

A method for determining the parameters of a turbulent flow of a gas mixture in a FAF  laser is presented. The method is based on analyzing the phase-conjugate wave intensity in intracavity degenerate four-wave mixing on nonlinearity of the active medium gain. The frequency distribution of the root-mean-square amplitude of fluctuations of the transverse velocity component and the boundary between viscosity and inertia are evaluated. The structural constant of velocity fluctuation in a turbulent flow and the coefficient of turbulent transverse diffusion are estimated.

A new method for measuring optical frequencies and lengths with a relative error of  by a highly stable femtosecond laser and a Fabry-Perot interferometer is proposed.

Results obtained by monitoring the geodynamic perturbations caused by the earthquake in December 26, 2004 in the Indian Ocean, which led to the disastrous tsunami on the coast are presented and discussed.

Some recommendations concerning the nonparametric probability density function estimators minimizing the mean integrated squared error are formulated.

An interferogram decoding algorithm robust to random errors in the case of misspecified phase shifts and also while determining average brightness and contrast of interference fringes is considered. It is shown that the proposed approach applies trajectory analysis of quadrature components used in the decoding algorithm.