The influence of non-vacuum electron-beam facing on the structure of Ti-Ta layers formed on the surface of VT1-0 alloy

The influence of electron-beam facing modes on the structure of Ti-Ta layers formed on the surface of commercially pure titanium VT1-0 has been studied in the paper. The mode of the electron-beam treatment of alloying powder mixture, by which there were no defects in the pad, has been identified. The methods of optical microscopy and scanning electron microscopy have shown that in pads there is dendritic segregation typical for the process of initial crystallisation. At greater magnifications it is possible to observe a structure of the laminar type. The X-ray phase analysis of titanium-tantalum layers justifies the presence of two phases: a hexagonal [alpha]'-phase and a cubic ([beta]-phase of titanium)

Eigenvalue estimates for non-selfadjoint Dirac operators on the real line

We show that the non-embedded eigenvalues of the Dirac operator on the real line with non-Hermitian potential $V$ lie in the disjoint union of two disks in the right and left half plane, respectively, provided that the $L^1-norm$ of $V$ is bounded from above by the speed of light times the reduced Planck constant. An analogous result for the Schr\"odinger operator, originally proved by Abramov, Aslanyan and Davies, emerges in the nonrelativistic limit. For massless Dirac operators, the condition on $V$ implies the absence of nonreal eigenvalues. Our results are further generalized to potentials with slower decay at infinity. As an application, we determine bounds on resonances and embedded eigenvalues of Dirac operators with Hermitian dilation-analytic potentials

Critical Temperature and Energy Gap for the BCS Equation

We derive upper and lower bounds on the critical temperature $T_c$ and the energy gap $\Xi$ (at zero temperature) for the BCS gap equation, describing spin 1/2 fermions interacting via a local two-body interaction potential $\lambda V(x)$. At weak coupling $\lambda \ll 1$ and under appropriate assumptions on $V(x)$, our bounds show that $T_c \sim A \exp(-B/\lambda)$ and $\Xi \sim C \exp(-B/\lambda)$ for some explicit coefficients $A$, $B$ and $C$ depending on the interaction $V(x)$ and the chemical potential $\mu$. The ratio $A/C$ turns out to be a universal constant, independent of both $V(x)$ and $\mu$. Our analysis is valid for any $\mu$; for small $\mu$, or low density, our formulas reduce to well-known expressions involving the scattering length of $V(x)$.Comment: RevTeX4, 23 pages. Revised version, to appear in Phys. Rev.

Automatic human action recognition in videos by graph embedding

The problem of human action recognition has received increasing attention in recent years for its importance in many applications. Yet, the main limitation of current approaches is that they do not capture well the spatial relationships in the subject performing the action. This paper presents an initial study which uses graphs to represent the actor's shape and graph embedding to then convert the graph into a suitable feature vector. In this way, we can benefit from the wide range of statistical classifiers while retaining the strong representational power of graphs. The paper shows that, although the proposed method does not yet achieve accuracy comparable to that of the best existing approaches, the embedded graphs are capable of describing the deformable human shape and its evolution along the time. This confirms the interesting rationale of the approach and its potential for future performance. © 2011 Springer-Verlag

Avaliação dos aspectos financeiros das pequenas e médias empresas: experiência russa

The aim of this study was to assess the key financials of an array of micro-sized businesses, small and medium-sized enterprises as grouped by industry. This article deals with the assessment results of such financials as the net financial result of enterprises, the proportion of profitable and loss-making enterprises, the profitability of manufactured and sold products, the current levels of profit and loss, respectively, per profitable and loss-making enterprise. The dynamics of such financials during the period from 2010 to 2014 was presented. Accounting and statistical reporting was used as the input data. In the course of this research it was proven that during that period the profitable enterprises accounted for about 80%. However, the level of profitability did not depend on the size of an enterprise. The largest proportion of profitable enterprises was noted in such sectors as education and commerce. The net financial result per employee in micro-enterprises was significantly higher than those for medium-sized enterprises and small enterprises. The results of this study may be used to validate business development plans and programs for various regions and sectors of the Russian economy. El objetivo de este estudio fue evaluar las finanzas clave de una serie de pequeñas empresas, pequeñas y medianas empresas agrupadas por industria. Este artículo trata de los resultados de la evaluación de tales finanzas como el resultado financiero neto de las empresas, la proporción de empresas rentables y que generan pérdidas, la rentabilidad de los productos fabricados y vendidos, los niveles actuales de ganancias y pérdidas, respectivamente, por rentabilidad y pérdida empresa de creación. La dinámica de tales finanzas durante el período 2010-2014 se presentó. Los informes contables y estadísticos se usaron como datos de entrada. En el curso de esta investigación, se comprobó que durante ese período las empresas rentables representaron aproximadamente el 80%. Sin embargo, el nivel de rentabilidad no depende del tamaño de una empresa. La mayor proporción de empresas rentables se observó en sectores como la educación y el comercio. El resultado financiero neto por empleado en las microempresas fue significativamente mayor que el de las medianas y pequeñas empresas. Los resultados de este estudio pueden usarse para validar planes y programas de desarrollo comercial para diversas regiones y sectores de la economía rusa. O objetivo deste estudo foi avaliar as principais finanças de uma série de microempresas, pequenas e médias empresas agrupadas por setor. Este artigo trata dos resultados da avaliação de tais finanças como o resultado financeiro líquido das empresas, a proporção de empresas lucrativas e deficitárias, a rentabilidade dos produtos fabricados e vendidos, os níveis atuais de lucros e perdas, respectivamente, por lucro e perda empresa de fabricação. A dinâmica de tais finanças durante o período de 2010 a 2014 foi apresentada. Relatórios contábeis e estatísticos foram usados como dados de entrada. No decorrer desta pesquisa, ficou provado que, durante esse período, as empresas lucrativas representavam cerca de 80%. No entanto, o nível de lucratividade não dependia do tamanho de uma empresa. A maior proporção de empresas lucrativas foi observada em setores como educação e comércio. O resultado financeiro líquido por empregado nas microempresas foi significativamente superior ao das médias empresas e pequenas empresas. Os resultados deste estudo podem ser usados para validar planos e programas de desenvolvimento de negócios para várias regiões e setores da economia russa

Lieb-Thirring inequalities for geometrically induced bound states

We prove new inequalities of the Lieb-Thirring type on the eigenvalues of Schr\"odinger operators in wave guides with local perturbations. The estimates are optimal in the weak-coupling case. To illustrate their applications, we consider, in particular, a straight strip and a straight circular tube with either mixed boundary conditions or boundary deformations.Comment: LaTeX2e, 14 page

Lower order terms in Szego type limit theorems on Zoll manifolds

This is a detailed version of the paper math.FA/0212273. The main motivation for this work was to find an explicit formula for a "Szego-regularized" determinant of a zeroth order pseudodifferential operator (PsDO) on a Zoll manifold. The idea of the Szego-regularization was suggested by V. Guillemin and K. Okikiolu. They have computed the second term in a Szego type expansion on a Zoll manifold of an arbitrary dimension. In the present work we compute the third asymptotic term in any dimension. In the case of dimension 2, our formula gives the above mentioned expression for the Szego-redularized determinant of a zeroth order PsDO. The proof uses a new combinatorial identity, which generalizes a formula due to G.A.Hunt and F.J.Dyson. This identity is related to the distribution of the maximum of a random walk with i.i.d. steps on the real line. The proof of this combinatorial identity together with historical remarks and a discussion of probabilistic and algebraic connections has been published separately.Comment: 39 pages, full version, submitte

Critical sound attenuation in a diluted Ising system

The field-theoretic description of dynamical critical effects of the influence of disorder on acoustic anomalies near the temperature of the second-order phase transition is considered for three-dimensional Ising-like systems. Calculations of the sound attenuation in pure and dilute Ising-like systems near the critical point are presented. The dynamical scaling function for the critical attenuation coefficient is calculated. The influence of quenched disorder on the asymptotic behaviour of the critical ultrasonic anomalies is discussed.Comment: 12 RevTeX pages, 4 figure