Search for glitches of gamma-ray pulsars with deep learning

The pulsar glitches are generally assumed to be an apparent manifestation of the superfluid interior of the neutron stars. Most of them were discovered and extensively studied by continuous monitoring in the radio wavelengths. The Fermi-LAT space telescope has made a revolution uncovering a large population of gamma-ray pulsars. In this paper we suggest to employ these observations for the searches of new glitches. We develop the method capable of detecting step-like frequency change associated with glitches in a sparse gamma-ray data. It is based on the calculations of the weighted H-test statistics and glitch identification by a convolutional neural network. The method demonstrates high accuracy on the Monte Carlo set and will be applied for searches of the pulsar glitches in the real gamma-ray data in the future works.Comment: 4 pages, 5 figure

Automatic selection of a subset size at vector fields construction

An algorithm for selection of the size of a correlation kernel at displacement vector field construction by the method of digital image correlation has been proposed. The algorithm has been tested on simulated and experimental optical images having different texture. The influence of the correlation kernel size and image texture on nose immunity at determining displacements has been studied. It is shown that the proposed algorithm allows to find this size providing the minimum error when determination of displacements and estimation of deformation

Research on submicron-grained structure formation in titanium alloys upon reversible hydrogenation and plastic deformation

The influence of thermohydrogen treatment combined with hot rolling on the structural formation in α- and near-α-titanium alloys has been studied. The prospects of obtaining submicron-grained sheet semifinished products of VT5 (Ti-5.8Al-0.1Fe, wt %) and VT20 (Ti-5.9Al-1.5V-1.2Mo-1.8Zr-0.1Fe, wt %) alloys are shown. In these materials, a submicron-grained structure allows the plastic deformation to be induced by superplasticity at temperatures reduced by 100-200°

Equivariant pretheories and invariants of torsors

In the present paper we introduce and study the notion of an equivariant pretheory: basic examples include equivariant Chow groups, equivariant K-theory and equivariant algebraic cobordism. To extend this set of examples we define an equivariant (co)homology theory with coefficients in a Rost cycle module and provide a version of Merkurjev's (equivariant K-theory) spectral sequence for such a theory. As an application we generalize the theorem of Karpenko-Merkurjev on G-torsors and rational cycles; to every G-torsor E and a G-equivariant pretheory we associate a graded ring which serves as an invariant of E. In the case of Chow groups this ring encodes the information concerning the motivic J-invariant of E and in the case of Grothendieck's K_0 -- indexes of the respective Tits algebras.Comment: 23 pages; this is an essentially extended version of the previous preprint: the construction of an equivariant cycle (co)homology and the spectral sequence (generalizing the long exact localization sequence) are adde

Influence of ion-beam treatment on structure and defor-mation resistance of 12Cr1MoV steel under static, cyclic and dynamic loading

Features of modification of structure and properties of 12Cr1MoV steel subjected to ion-beam irradiation by zirconium ion beam have been investigated with the use of optical and electron microscopy, and microhardness measurement. It was shown that after the treat-ment the modification occurs across the entire cross-section of specimens with the thickness of 1 mm. Changes in mechanical properties of these specimens under static, cyclic and impact loading were interpreted in terms of identified structure modifications

Effect of grain refinement on deformation behavior of technical grade titanium under tension

The paper deals with the study on the impact of grain refinement by severe plastic deformation upon the microstructure, as well as deformation and fracture behavior under tensile loading of technical grade titanium. The microstructure of coarse- and ultra-fine grain technical grade titanium was investigated by optical, transmission electron microscopy and X-ray diffraction. In situ monitoring of deformation behavior was conducted by means of acoustic emission and digital image correlation. Scanning electron microscopy was employed for fracture surface observation. The results of the tensile tests have revealed significant growth in ultimate strength and decrease of ductility due to grain-boundary strengthening. The experimental data obtained allow one to get the appropriate understanding of the mechanisms responsible for variation of mechanical properties and fracture patterns as well as to attain quantitative estimation of strain localization induced by the grain refinement