Mathematical modeling of three-layer beam hydroelastic oscillations

The problem of hydroelastic oscillations of three-layer beam interacting with viscous liquid layer is set up and analytically solved. The problem presents the equation system of a three-layer beam and Navier-Stokes equations. The following boundary conditions are chosen: the no-slip conditions, the conditions for pressure at the edges, the simply supported edges conditions. The problem is solved for the steady-state harmonic regime. The frequency dependent distribution functions of the beam deflection are constructed. The given function allows investigating the resonance hydroelastic oscillations of a three-layer beam, as well as its deflected mode

Narrow-domain Short Texts Clustering Algorithm

In this paper, we describe the algorithm of narrow-domain short texts clustering, which is based on terms’ selection and modification of k-means algorithm. Our approach was tested on collections: CICling–2002 and SEPLIN-CICling. Results of tests and conclusions are presented

Reply to comment on the paper “ on a role of quadruple component of magnetic field in defining solar activity in grand cycles” by Usoskin (2017)

In this communication we provide our answers to the comments by Usoskin (2017) on our recent paper (Popova et al, 2017a). We show that Principal Component Analysis (PCA) allows us to derive eigen vectors with eigen values assigned to variance of solar magnetic field waves from full disk solar magnetograms obtained in cycles 21–23 which came in pairs. The current paper (Popova et al, 2017a) adds the second pair of magnetic waves generated by quadruple magnetic sources. This allows us to recover a centennial cycle, in addition to the grand cycle, and to produce a closer fit to the solar and terrestrial activity features in the past millennium

Comparison of solar activity proxies: eigen vectors versus averaged sunspot numbers

We attempt to establish links between a summary curve, or modulus summary curve, MSC, of the solar background magnetic field (SBMF) derived from Principal Component Analysis, with the averaged sunspot numbers (SSN). The comparison of MSC with the whole set of SSN reveals rather close correspondence of cycle timings, duration and maxima times for the cycles 12- 24, 6,7 and -4,-3. Although, in 1720-1760 and 1830-1860 there are discrepancies in maximum amplitudes of the cycles, durations and shifts of the maximum times between MSC and SSN curves. The MSC curve reveals pretty regular cycles with double maxima (cycles 1-4), triple maximum amplitude distributions for cycles 0 and 1 and for cycles -1 and -2 just before Maunder minimum. The MSC cycles in 1700-1750 reveal smaller maximal magnitudes in cycles -3 to 0 and in cycle 1-4 than the amplitudes of SSN, while cycles -2 to 0 have reversed maxima with minima with SSN. Close fitting of MSC or Bayesian models to the sunspot curve distorts the occurrences of either Maunder Minimum or/and modern grand solar minimum (2020-2053). These discrepancies can be caused by poor observations and by difference in solar magnetic fields responsible for these proxies. The dynamo simulations of toroidal and poloidal magnetic field in the grand solar cycle (GSC) from 1650 until 2050 demonstrate the clear differences between their amplitude variations during the GSC. The use of eigen vectors of SBMF can provide additional information to that derived from SSN that can be useful for understanding solar activity.Comment: 23 pages, 9 figur

Inversionless light amplification and optical switching controlled by state-dependent alignment of molecules

We propose a method to achieve amplification without population inversion by anisotropic molecules whose orientation by an external electric field is state-dependent. It is based on decoupling of the lower-state molecules from the resonant light while the excited ones remain emitting. The suitable class of molecules is discussed, the equation for the gain factor is derived, and the magnitude of the inversionless amplification is estimated for the typical experimental conditions. Such switching of the sample from absorbing to amplifying via transparent state is shown to be possible both with the aid of dc and ac control electric fields.Comment: AMS-LaTeX v1.2, 4 pages with 4 figure

Priority areas of development of resources of hydrocarbons of Hlynskyi and Solokhivskyi oil and gas region of Dnipro and Donetsk basin

The resource potential of the Hlynsko-Solokhivskyi oil and gas region, selected area of oil and gas accumulation (OGA) was described. By means of graphical analysis the extent of the area resource potential development and selected areas of OGA was defined. The analysis of non-discovered resources (including localized) in areas, promising and producing complexes and deeps was made. The most promising areas were determined. The appropriate recommendations on further geology exploration for the purpose of improving the efficiency on oil and gas were given