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Vol 62, No 8 (2017)

Physics

Generation of magnetic field waves in celestial bodies by spatially separated sources

Popova E.P.

Abstract

For a plane layer we have analytically shown that in the case of spatially separated magnetic field generation sources, waves with different frequencies dependent on the physical parameters of the sources (dynamo numbers) emerge in a celestial body. Each of the waves interacts mainly with its source, while the degree of mutual overlapping of the waves decreases with increasing distance between the sources.

Doklady Physics. 2017;62(8):371-373
pages 371-373 views

Technical Physics

A robust method for the reconstruction of disparity maps based on multilevel processing of stereo color image pairs

Kravchenko V.F., Ponomaryov V.I., Pustovoit V.I., Sadovnychiy S.N.

Abstract

A novel method for the reconstruction of disparity maps (DMs) with robust properties to nonideal registration conditions, reflections, and noise in stereo color image pairs has been substantiated for the first time. The novel approach proposes a scheme for image DM reconstruction where Jaccard distance metric is used as a proximity criterion in stereo image pair matching. A physical interpretation of the method that allows the quality of the formed DMs to be improved significantly is given. A processing block diagram has been developed in accordance with the novel approach. Simulations of the novel DM reconstruction method have shown an advantage of the proposed DM reconstruction scheme in terms of generally recognized criteria, such as the structural similarity index measure and the bad matching pixels, and when visually comparing the formed DMs.

Doklady Physics. 2017;62(8):374-378
pages 374-378 views

Complex noise suppression using a sparse representation and 3D filtering of images

Kravchenko V.F., Ponomaryov V.I., Pustovoit V.I., Palacios-Enriquez A.

Abstract

A novel method for the filtering of images corrupted by complex noise composed of randomly distributed impulses and additive Gaussian noise has been substantiated for the first time. The method consists of three main stages: the detection and filtering of pixels corrupted by impulsive noise, the subsequent image processing to suppress the additive noise based on 3D filtering and a sparse representation of signals in a basis of wavelets, and the concluding image processing procedure to clean the final image of the errors emerged at the previous stages. A physical interpretation of the filtering method under complex noise conditions is given. A filtering block diagram has been developed in accordance with the novel approach. Simulations of the novel image filtering method have shown an advantage of the proposed filtering scheme in terms of generally recognized criteria, such as the structural similarity index measure and the peak signal-to-noise ratio, and when visually comparing the filtered images.

Doklady Physics. 2017;62(8):379-383
pages 379-383 views

Mechanics

The problem of high-temperature creep and long-term strength in the mechanics of materials

Arutyunyan R.A.

Abstract

The damage parameter is determined as the relative change in volume or density. It is considered that this parameter is an integral characteristic of the damage.

Doklady Physics. 2017;62(8):384-386
pages 384-386 views

On the structure of the set of probable Earth-impact trajectories for the asteroid Apophis in 2036

Ivashkin V.V., Stikhno C.A., Guo P.

Abstract

The probable set of Earth-collision trajectories for the asteroid Apophis in 2036 has been determined. The characteristics of these trajectories and the corresponding probable asteroid impact zone on the Earth have been analyzed.

Doklady Physics. 2017;62(8):387-391
pages 387-391 views

New cases of integrable systems with dissipation on a tangent bundle of a two-dimensional manifold

Shamolin M.V.

Abstract

The integrability of certain classes of dynamic systems is shown on the tangent bundles to twodimensional manifolds. In this case, the force fields have the so-called variable dissipation and generalize the previously considered fields.

Doklady Physics. 2017;62(8):392-396
pages 392-396 views

Polynomial integrals of mechanical systems on a torus with a singular potential

Denisova N.V.

Abstract

The problem on integrability of the equations of motion of a material point on an n-dimensional Euclidean torus under the action of a force field with the potential energy having singularities at a finite number of points is considered. It is assumed that these singularities contain logarithmic coefficients and, consequently, have a more general form in comparison with power features. The potentials having power-type singularities were considered previously by V.V. Kozlov and D.V. Treshchev. In this work, it is proved that the equations of motion in the problem under consideration admit no nontrivial momentum-polynomial first integral with integrable coefficients on this torus.

Doklady Physics. 2017;62(8):397-399
pages 397-399 views

On solving continuum-mechanics problems by fast multipole methods

Linkov A.M., Rejwer E., Rybarska-Rusinek L.

Abstract

It is shown analytically and numerically that the kernel-independent fast multipole method provides the accuracy and computational complexity of the analytical method if circular (spherical in 3D) equivalent surfaces are used.

Doklady Physics. 2017;62(8):400-402
pages 400-402 views

Astronomy, Astrophysics, Cosmology

Similarity and dimensional theory for galaxies: Explanation of long-known results of observations

Golitsyn G.S.

Abstract

A practical extension of the similarity and dimensional theory to the case of several similarity parameters is proposed. On this basis, for galaxies an explanation is given for the empirical correlations noticed in the last quarter of the 20th century: the Tully–Fisher relation, the concept of a fundamental plane, etc. For galaxies, apart from the virial, there is another similarity parameter whose choice is arbitrary. Here, it is introduced in the simplest form for an empirical determination:Π1 = U0/Ud, U0 is the observed velocity, the scale Ud = (GL)1/5, where L is the object luminosity, G is the gravitational constant.

Doklady Physics. 2017;62(8):403-406
pages 403-406 views