Volume 54, Nº 5 (2018)

A combinatorial-discrete approach to solving continuous probabilistic problems arising in the analysis of random point structures is proposed. It is based on replacement of computational schemes based on calculations of cumbersome multidimensional integral expressions by schemes that do not require the use of the apparatus of differential and integral calculus. Another distinctive feature of the study is the systematic use of the generalized Catalan numbers from the multidimensional extension of the classical Catalan sequence for ranking random mutually dependent sequences.

Correction algorithm for digital terrain models derived from remote sensing of the Earth’s surface are analyzed. The accuracy of the ASTER GDEM2, SRTM X-band, and ALOS DMS global digital elevation models were analyzed, showing that ALOS DMS images have the smallest absolute and relative errors for different relief conditions (flat, hilly and highly dissected plains) of the Novosibirsk oblast’. A comparative analysis of the algorithms proposed by Wang and Liu, Plantchon and Darboux, Pelletier, and Tarboton was performed to eliminate artifacts on original satellite images associated with local topographic lows (depressions, pits). The smallest errors for different terrain conditions were obtained using the algorithm of Wang and Liu.

A filtration algorithm is proposed for detecting objects in images obtained by means of microscanning. An algorithm for calculating the filter for an object with a known shape is presented. The influence of changes in the object shape induced by a subpixel displacement of the object with respect to the center of the photosensitive cell on the filtration results is studied. An approach to choosing the filter shape with allowance for object shape changes is tested. Results of numerical simulations are reported.

The paper presents a brief analytical review of papers dealing with the use of simple binaryphase diffractive structures in multifocal artificial eye lenses (intraocular lenses) to increase the focal region. The results of theoretical studies of the influence of spherical aberrations of the eye, the optical power of the diaphragm (pupil diameter), and the duty cycle of the structure on the depth of focus (limits of clear vision) are given. The intensity distribution in diffraction orders (foci) in the simplest binary diffractive-refractive intraocular lenses is analyzed.

This paper describes the autocollimation optical scheme of a fluorimeter that allows detecting different reactions from multiple wells of a microplate at the same time. The image focusing is implemented a spherical mirror that excludes the presence of background illumination and chromatic aberration. The operation of the fluorimeter is demonstrated by measuring a signal from the microplate with 96 and 384 individual wells.

A new class of capacitive motors based on nanometer gaps between the electrodes and possessing specific power capacity values much higher than that of inductive motors is described. Specific features of their operation are analyzed. The specific energy generated in a cycle of electromechanical conversion is estimated. The forces and powers of the considered motors are found to exceed the corresponding parameters of inductive motors by 2–3 orders of magnitude, which offers a possibility of using them in numerous applications.

Results of an experimental study of a thin-film pyroelectric detector of radiation based on strontium barium niobate and used for detecting nanosecond radiation pulses are reported. The possibility of recording 30-ns radiation pulses with the sensitivity of 1 V/W (NEP = 8 · 10⁻⁷ W/Hz^1/2) is demonstrated.

A modified method of fuzzy clustering is proposed for determining the aerodynamic characteristics of an aircraft from flight test data. This approach allows one to describe the aerodynamic characteristics of an aircraft in the form of a black box model with inputs in the form of telemetry data, such as accelerations, angular velocities, thrust, and dynamic pressure, and with outputs in the form of dimensionless aerodynamic coefficients of forces and moments. Results of modeling in the MATLAB/Simulink environment are reported.

This paper describes the problem of controlling a quadrotor motion in payload transportation on suspension. The suspension is a weightless rod pivotally fixed at the quadrotor mass center with a payload on its end. Equations of motion for a two-dimensional model are obtained using Lagrange equations of the second kind, which serve as a basis for a model revealing the suspension oscillations that destabilize the system. We proposed a controller based on the structural synthesis method and including the deflection angle of the rod from the vertical. The efficiency of the algorithm is confirmed by the simulation results.