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Dikonov V.G.,Russian Academy of Sciences | Poritski V.V.,BSU
Komp'juternaja Lingvistika i Intellektual'nye Tehnologii | Year: 2014

There are areas in computational linguistics, where a word-sense tagged corpus becomes a necessary prerequisite or gives a significant boost to research. Unfortunately, publicly available corpora of this kind are extremely rare and making them from scratch is a very long and costly process. No corpus of Russian with unambiguous word-sense tags has been published so far. This paper describes an experimental approach of creating a virtual equivalent of a Russian sense tagged corpus and putting it to some real use. The virtual corpus was created using two public resources: The English SemCor corpus and our free multilingual semantic pivot dictionary, called the "Universal Dictionary of Concepts". The dictionary provides information sufficient to find sense-specific translations for nearly all sensetagged words in SemCor. However, the pivot dictionary itself is under development and we are looking for the ways to improve it. We used the existing Russian volume of the pivot dictionary to calculate lexical context vectors for individual senses of 13,832 Russian words, supposedly equivalent to the vectors that could be obtained from a real Russian translation of SemCor. Another set of vectors representing real usage of the same Russian words was extracted from a medium-size corpus of Russian without any semantic markup. The vector similarity score proved to be a useful factor in judging the correctness of links between Russian words and word senses similar to ones registered in the Princeton Wordnet. It helped to rank over 21,000 of such links out of 56,000 known and significantly reduce the amount of the manual work required to proofread the dictionary.

Malevich A.E.,BSU | Mityushev V.V.,Pedagogical University of Cracow | Adler P.M.,University Pierre and Marie Curie
Journal of Colloid and Interface Science | Year: 2010

Electroosmotic flows are studied in wavy channels by expanding the solution into a double series in terms of the dimensionless amplitudes and of the dimensionless zeta potential for a binary dilute electrolyte. The expansion technique by means of formal calculations is described. Some examples are illustrated and discussed for two- and three-dimensional channels. The importance of the varicose or sinuous character of the channels as well as the role of high frequency roughness are demonstrated. These features may be used for practical purposes in order to amplify or diminish coupling effects in an algebraic way. © 2010 Elsevier Inc. All rights reserved.

Potapenko T.A.,Power Engineering Institute | Shtifanov A.I.,BSU | Potapenko A.N.,Power Engineering Institute
2014 International Conference on Lightning Protection, ICLP 2014 | Year: 2014

Paper presents statement of problem and the results of mathematical modeling of different schemes of lightning protection system (LPS) on example of launch pads and steel towers of power transmission lines (PTL). The method of mathematical modeling based on solving an elliptic equation (method MMSEE) with respect to the electric flow function is used for the calculation of family of force lines of electric field. The features of the applied MMSEE for problems of practical importance with a goal to calculate the electric force lines with respect to the grounding electrode near the buried part of a reinforced concrete pole are presented at the condition of rain. © 2014 IEEE.

Radu E.,University of Oldenburg | Shnir Y.,BSU | Tchrakian D.H.,DIAS
AIP Conference Proceedings | Year: 2010

We construct static, asymptotically flat solutions of SU(2) Einstein-Yang-Mills (EYM) theory in 4+1 dimensions, subject to bi-azimuthal symmetry. The results are compared with similar solutions of the SU(2) Yang - Mills - dilaton (YMd) model. Both particle-like and black hole solutions are considered. © 2010 American Institute of Physics.

Adler P.M.,University Pierre and Marie Curie | Malevich A.E.,BSU | Mityushev V.V.,Pedagogical University of Cracow
Acta Mechanica | Year: 2013

For low Reynolds numbers ℝ, the flow of a viscous fluid through a channel is described by the well-known Darcy's law which corresponds to a linear relation between the pressure gradient ∇̄p}} and the average velocity ū. When the channel is not straight and when the Reynolds number is not negligible, additional terms appear in this relation. Some previous authors investigated the first three coefficients in the expansion of |∇̄p| in the powers of ū and they showed that the coefficient of ū2 vanishes for moderate ℝ. Other authors demonstrated that this coefficient can be non-zero. This question is addressed and solved. It is demonstrated that both cases occur; Forchheimer's law has a cubic correction for small ℝ and a quadratic one for large ℝ. Two analytical-numerical algorithms are constructed to prove this property. These algorithms are applied to the Navier-Stokes equations in three-dimensional channels enclosed by two wavy walls whose amplitude is proportional to bε, where 2b is the mean clearance of the channels and ε is a small dimensionless parameter. The first algorithm is applied for small ℝ by representing the velocity and the pressure in terms of a double Taylor series in ℝ and ε. The accuracy O(ℝ2) and O(ε6) following Padé approximations yield analytical approximate formulae for Forchheimer's law. The first algorithm is applied to symmetric channels on the theoretical level (all terms on ℝ and ε are taken into account) to show that |∇̄p| is an odd function of ū. This observation yields, in particular, a cubic correction to Darcy's law. Numerical examples for non-symmetrical channels yield the same cubic correction. The second algorithm is based on the analytical-numerical solution to the Navier-Stokes equations for arbitrary ℝ up to O(ε3). This algorithm yields, in particular, a quadratic correction to Darcy's law for higher ℝ. © 2013 Springer-Verlag Wien.

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