Труды сотрудников ИВМ СО РАН

[Text] / H. K. Biernat, N. V. Erkaev, C. J. Farrugia // PLANETARY MAGNETOSPHERES. Ser. ADVANCES IN SPACE RESEARCH : ELSEVIER SCIENCE BV, 2001. - Vol. 28: D3 1/C3 3 Symposium of COSPAR Scientific Commission D held at the 33rd COSPAR Scientific Assembly (JUL, 2000, WARSAW, POLAND), Is. 6. - P833-839, DOI 10.1016/S0273-1177(01)00525-7. - Cited References: 12 . - ISBN 0273-1177РУБ Engineering, Aerospace + Astronomy & Astrophysics + Geosciences, Multidisciplinary + Meteorology & Atmospheric Sciences

Аннотация: We use the "magnetic string" approach to integrate the dissipationless MHD equations for a 3-D flow around planetary obstacles, and apply it to some aspects of the flow in the magnetosheath of Venus. Our method has both analytical and numerical components, and is particularly suited to study the structure of the magnetic barrier (depletion layer). Including pick-up processes, we study the contribution to the structure of the Venus magnetosheath made by the pick-up ions. As one main conclusion, we show that the used method leads to a stand-off bow shock position which in good agreement with observations. (C) 2001 COSPAR. Published by Elsevier Science Ltd. All rights reserved.


Доп.точки доступа:
Biernat, H.K.; Erkaev, N.V.; Еркаев, Николай Васильевич; Farrugia, C.J.

[Text] / N. V. Erkaev [et al.] // COORDINATED MEASUREMENTS OF MAGNETOSPHERIC PROCESSES. Ser. ADVANCES IN SPACE RESEARCH : PERGAMON PRESS LTD, 2000. - Vol. 25: D0 1 Symposium of COSPAR Scientific Commission D Held at the 32nd COSPAR Scientific Assembly (JUL 12-19, 1998, NAGOYA, JAPAN), Is. 07.08.2013. - P1523-1528, DOI 10.1016/S0273-1177(99)00665-1. - Cited References: 18 . - ISBN 0273-1177РУБ Engineering, Aerospace + Astronomy & Astrophysics + Geosciences, Multidisciplinary + Meteorology & Atmospheric Sciences

Аннотация: We extend our "magnetic string" MHD model describing the flow of the shocked solar wind around the magnetosphere to include an anisotropic plasma pressure with p(perpendicular to) p(parallel to). Thermodynamic properties are determined by the law of conservation of energy of a magnetic string associated with a magnetic field line. The MHD equations are closed by a relation between p(perpendicular to) and p(parallel to) corresponding to the threshold of the electromagnetic proton cyclotron wave instability. Assuming no flow across the magnetopause, we compare profiles of the steady-state magnetic field and plasma parameters along the subsolar line for upstream sonic and Alfven Mach numbers = 10 with the isotropic case (p(perpendicular to) = p(parallel to)). In the anisotropic model, besides the density, both temperatures, plasma pressures and betas decrease toward the magnetopause. The temperature and plasma pressure parallel to the magnetic field decrease more strongly than those perpendicular to the field. Profiles for temperature and pressure in the case of isotropy lie between those of corresponding parallel and perpendicular values, but closer to the latter. The gradient of B near the magnetopause is larger than for isotropic pressure. (C) 2000 COSPAR. Published by Elsevier Science Ltd.


Доп.точки доступа:
Erkaev, N.V.; Еркаев, Николай Васильевич; Farrugia, C.J.; Biernat, H.K.; Ogilvie, K.W.; Quinn, J.M.

[Text] / H. K. Biernat, N. V. Erkaev, C. J. Farrugia // J. Geophys. Res-Space Phys. - 1999. - Vol. 104, Is. A6. - P12617-12626, DOI 10.1029/1999JA900032. - Cited References: 37 . - ISSN 0148-0227РУБ Astronomy & Astrophysics

Аннотация: We describe the "magnetic string" approach to integrating the dissipationless magnetohydrodynamic (MHD) equations for flow around planetary obstacles and apply it to some aspects of the flow in the magnetosheath of Venus. Our method has both analytical and numerical components and is particularly suited to study the structure of the magnetic barrier (depletion layer). We do not include ion pickup processes and thus discuss only the contribution to the structure of the Venus magnetosheath made by the flow of the shocked solar wind. We work with an interplanetary magnetic field which is directed orthogonal to the solar wind bulk velocity. Magnetic forces on the flow are strongly dependent on the Alfven Mach number upstream of the bow shock, and one aim of this work is to study the dependence of field and flow quantities in the Venus magnetosheath on this parameter, thus allowing further future comparisons with data under a variety of interplanetary conditions. A second aim is to compare our MHD model results to a? synopsis of observations made by the Pioneer Venus Orbiter. As one main conclusion, we show that this method leads, in principle, to a standoff bow shock position in good agreement with observations. We find, namely, that for a low but reasonable Alfven Mach number, our MHD-modeled magnetosheath is only similar to 3.6% thinner in the Sun-Venus direction than that given by observations. Our method is complementary to three-dimensional, global MHD simulations of the solar wind-Venus interaction and offers versatility to modeling other aspects of the complicated interaction of the solar wind with Venus.


Доп.точки доступа:
Biernat, H.K.; Erkaev, N.V.; Еркаев, Николай Васильевич; Farrugia, C.J.

[Text] / N. V. Erkaev, C. J. Farrugia, H. K. Biernat // J. Geophys. Res-Space Phys. - 1999. - Vol. 104, Is. A4. - P6877-6887, DOI 10.1029/1998JA900134. - Cited References: 29 . - ISSN 0148-0227РУБ Astronomy & Astrophysics

Аннотация: We present a three-dimensional, one-fluid, steady state magnetohydrodynamic (MHD) model of magnetosheath flow near the subsolar line with unequal plasma pressures perpendicular (P-perpendicular to) and parallel (P-parallel to) to the magnetic field (P-perpendicular to P-parallel to) Aside from an assumption on the total pressure normal to the magnetopause, our analytical-numerical method is completely general and is an extension of our isotropic, "magnetic string" MHD model, which we describe in detail here. The MHD equations are closed by a relation between P-perpendicular to and P-parallel to as in the Bounded Anisotropy Model [Denton et al., 1994] corresponding to the threshold of the electromagnetic proton cyclotron wave instability. We take an IMF oriented perpendicular to the solar wind velocity. As boundary conditions, we have Rankine-Hugoniot relations at the bow shock and a no-flow condition at the magnetopause. We obtain steady state profiles of the magnetic field and plasma parameters for upstream sonic and Alfven Mach numbers equal to 10, and compare them with the isotropic case (P-parallel to = P-perpendicular to). Anisotropy slightly thickens the magnetosheath. In the anisotropic model, the density, the parallel and perpendicular temperatures, plasma pressures, and betas all decrease toward the magnetopause. Isotropic profiles lie between those of quantities perpendicular and parallel to the field. Anisotropy has considerable effect on the density profile, which lies below that in the isotropic limit throughout the magnetosheath. Density depletion results from stretching of magnetic field lines, which is caused by field-aligned plasma flow. Approaching the magnetopause, the tangential component of velocity parallel to the magnetic field decreases, while the tangential component perpendicular to the magnetic field increases. These are features characterizing a stagnation line flow at the magnetopause. The acceleration along the magnetic field is produced by the gradient of P-parallel to and the mirror force, which depends on anisotropy. They both make substantial contributions and are responsible for the changes we see;from isotropy. The acceleration perpendicular to magnetic field is also larger than in the case of isotropy and is caused by the gradient of total pressure, the magnetic strength, and the mirror force. In addition, acceleration in both directions is affected by the decreasing density.


Доп.точки доступа:
Erkaev, N.V.; Еркаев, Николай Васильевич; Farrugia, C.J.; Biernat, H.K.

[Текст] / V. S. SEMENOV, N. V. ERKAEV // Geomagn. Aeron. - 1989. - Vol. 29, Is. 2. - С. 222-227. - Cited References: 13 . - ISSN 0016-7940РУБ Geochemistry & Geophysics


Доп.точки доступа:
SEMENOV, V.S.; Erkaev, N.V.; Еркаев, Николай Васильевич

[Text] / N. V. Erkaev [et al.] // Geophys. Res. Lett. - 2011. - Vol. 38. - Ст. L01104, DOI 10.1029/2010GL045998. - Cited References: 20. - This work was done while N.V.E. was on a research visit to the Space Science Center of UNH. This work is supported by RFBR grant N 09-05-91000-ANF_a and also by the Austrian "Fonds zur Forderung der wissenschaftlichen Forschung" under project I 193-N16 and the "Verwaltungsstelle fur Auslandsbeziehungen" of the Austrian Academy of Sciences. Work by C.J.F. was supported by NASA grants NNX10AQ29G and NNX08AD11G. . - ISSN 0094-8276РУБ Geosciences, Multidisciplinary

Аннотация: We study the acceleration of magnetosheath plasma using a semi-analytical magnetic string approach for a range of solar wind Alfven Mach numbers, M-A, between 2 and 20. We work with an IMF vector perpendicular to the solar wind velocity, V-sw, and pointing north. We do not invoke magnetic reconnection. Our results indicate that magnetosheath speeds can exceed the solar wind speed, and the ratio V/V-sw increases with decreasing M-A. Analyzing the dependence of this ratio on M-A, we find that for M-A = 2, maximum V/V-sw approximate to 1.6, and for M-A = 10-20, maximum V/V-sw varies from 1.21 to 1.13. Maximum speeds occur a few Earth radii (R-E) tailward of the dawn-dusk terminator. The thickness of the accelerated flow layer varies as M-A(-2). Taking the magnetopause subsolar distance as 10 R-E, we find typical values for the thickness of similar to 4 R-E for M-A = 3 and 0.35 R-E for M-A = 10. The physical mechanism is that of draping of the magnetic field lines around the magnetosphere, and the associated magnetic tension and total pressure gradient forces acting on the flow. For lower M-A the plasma depletion is stronger, and thus the acceleration produced by the pressure gradient is larger. An additional acceleration is produced by the magnetic tension, which is stronger for smaller M-A. At the dayside the pressure gradient and magnetic tension forces both act in the same direction. But tailward of the terminator the magnetic tension starts to act in the opposite direction to the pressure gradient. When the resulting force vanishes, the highest speed is attained. Citation: Erkaev, N. V., C. J. Farrugia, B. Harris, and H. K. Biernat (2011), On accelerated magnetosheath flows under northward IMF, Geophys. Res. Lett., 38, L01104, doi: 10.1029/2010GL045998.


Доп.точки доступа:
Erkaev, N.V.; Еркаев, Николай Васильевич; Farrugia, C.J.; Harris, B.; Biernat, H.K.

[Text] / I. Borovikov, M. Sadovsky ; ed. S. . Battiston [et al.] // PROCEEDINGS OF ECCS 2014: EUROPEAN CONFERENCE ON COMPLEX SYSTEMS : SPRINGER, 2016. - European Conference on Complex Systems (ECCS) (SEP 22-26, 2014, IMT Sch Adv Studies Lucca, Lucca, ITALY). - P155-167. - (Springer Proceedings in Complexity), DOI 10.1007/978-3-319-29228-1_14. - Cited References:9 . - ISBN 978-3-319-29228-1; 978-3-319-29226-7РУБ Computer Science, Theory & Methods + Mathematics, Applied

Аннотация: Discretization of time series and encoding it as a string in a finite alphabet allows application of information theory methods developed for discrete signals. Computing information values of n-grams extracted from such string leads to introduction of events as occurrences of n-grams that possess specific properties, e.g. abnormally high (or low) information value. We define information value of an n-gram via maximum entropy lifts over frequency dictionaries. We also look for correlation between market events and n-gram events. The paper shows that the proposed method of time series analysis when applied to events study may provide new insightful perspective.

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Держатели документа:
Nekkar Net Int Labs, 51 Commons Ln, Foster City, CA 94404 USA.
Inst Computat Modelling SB RAS, Krasnoyarsk, Russia.

Доп.точки доступа:
Borovikov, Igor; Sadovsky, M.G.; Садовский, Михаил Георгиевич

[Текст] : статья / Михаил Георгиевич Садовский, Анна Игоревна Чернышова // Образовательные ресурсы и технологии. - 2016. - № 2. - С. 250-253 . - ISSN 2312-5500
   Перевод заглавия: Towards the correspondence between structure of pine chloroplast genomes and their phylogeny

УДК

519.95

Аннотация: В работе представлены предварительные результаты по изучению связи между структурой и таксономией геномов хвойных хлоропластов, полученные методом динамических ядер. Данная связь была выявлена. Показаны особенности применяемых методов, а также представлены выводы по полученным результатам
Some results are presented exploring the problem of the relation between the phylogeny of various species and taxa, and the structure of corresponding DNA sequences. The features of the methods used are shown in this work. And also presents conclusions on the results obtained

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Держатели документа:
Институт вычислительного моделирования СО РАН
Сибирский федеральный университет, ИФБиБТ

Доп.точки доступа:
Чернышова, Анна Игоревна; Chernyshova Anna Igorevna; Sadovskii M.G.

/ M. Sadovsky [et al.] // (26 April 2017 through 28 April 2017 : Springer Verlag, 2017. - Vol. 10209 LNCS. - P20-29, DOI 10.1007/978-3-319-56154-7_3 . -
Аннотация: We studied the sets of avoided strings to be observed over a family of genomes. It was found that the length of the minimal avoided string rarely exceeds 9 nucleotides, with neither respect to a phylogeny of a genome under consideration. The lists of the avoided strings observed over the sets of (related) genomes have been analyzed. Very low correlation between the phylogeny, and the set of those strings has been found. © Springer International Publishing AG 2017.

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Держатели документа:
Institute of Computational Modelling of SB RAS, Akademgorodok, Krasnoyarsk, Russian Federation
Johannes Gutenberg-Universitat Mainz, Mainz, Germany
Institute of Space and Information Technologies, Siberian Federal University, Kirenskogo Str., 26, Krasnoyarsk, Russian Federation
Institute of Molecular Biology, Mainz, Germany

Доп.точки доступа:
Sadovsky, M.; Fontaine, J. -F.; Andrade-Navarro, M. A.; Yakubailik, Y.; Rudenko, N.

/ Y. Grebnev, M. Sadovskiy ; ed. O. G. Berestneva [et al.] // PROCEEDINGS OF THE IV INTERNATIONAL RESEARCH CONFERENCE INFORMATION : ATLANTIS PRESS, 2017. - Vol. 72: 4th International Scientific Research Conference on Information (DEC 05-08, 2017, Tomsk, RUSSIA). - P368-370. - (ACSR-Advances in Comptuer Science Research), DOI 10.2991/itsmssm-17.2017.76. - Cited References:4 . -
Аннотация: Some preliminary results are provided towards the study of the violation of genomic super-symmetry; that latter is the so called Second Chargaff's rule. The rule stipulates that oligonucleotides that could be read equally in opposite directions with respect to the symbol change according to the complimentary law (complimentary palindromes) should exhibit pretty close frequency. We have checked the genomes of organisms of various taxa ranging from viruses via bacteria, yeasts, animals, plants, etc.; more than 1500 genetic sequences had been studied, totally. The measure for the second rule violation was calculated for a single strand. Both intragenomic, and intergenomic studies have been carried out. It was found that intragenomic variability decays, as the length of string grows up. The intergenomic variability is comparable to the intragenomic one, for considerably short strings.

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Держатели документа:
Siberian Fed Univ, Krasnoyarsk, Russia.
Russian Acad Sci, Siberian Branch, Inst Computat Modeling, Krasnoyarsk, Russia.

Доп.точки доступа:
Grebnev, Yaroslav; Sadovskiy, Michail; Berestneva, O.G. \ed.\; Tikhomirov, A.A. \ed.\; Trufanov, A.I. \ed.\; Kataev, M.Y. \ed.\

[Текст] : доклад, тезисы доклада / Я. В. Гребнев, М. Г. Садовский // Информационные технологии в науке, управлении, социальной сфере и медицине : сборник научных трудов IV Международной конференции: в 2 частях. - Томск : Национальный исследовательский Томский политехнический университет, 2017. - Часть 1. - С. 60-62
Аннотация: Some preliminary results are provided towards the study of the violation of genomic super-symmetry; that latter is the so called Second Chargaff's rule. The rule stipulates that oligonucleotides that could be read equally in opposite directions with respect to the symbol change according to the complimentary law (complimentary palindromes) should exhibit pretty close frequency. We have checked the genomes of organisms of various taxa ranging from viruses via bacteria, yeasts, animals, plants, etc.; more than 1500 genetic sequences had been studied, totally. The measure for the second rule violation was calculated for a single strand. Both intragenomic, and intergenomic studies have been carried out. It was found that intragenomic variability decays, as the length of string grows up. The intergenomic variability is comparable to the intragenomic one, for considerably short strings.

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Держатели документа:
Институт вычислительного моделирования Сибирского отделения Российской академии наук
Сибирский федеральный университет

Доп.точки доступа:
Гребнев, Я.В.; Садовский, М.Г.; ИНФОРМАЦИОННЫЕ ТЕХНОЛОГИИ В НАУКЕ, УПРАВЛЕНИИ, СОЦИАЛЬНОЙ СФЕРЕ И МЕДИЦИНЕ(2017 ; 05.12 - 08.12 ; Томск)
Нет сведений об экземплярах (Источник в БД не найден)

/ M. Sadovsky [et al.] // (8 May 2019 through 10 May 2019 : Springer Verlag, 2019. - Vol. 11465 LNBI. - P271-282, DOI 10.1007/978-3-030-17938-0_25 . -
Аннотация: Distribution of read starts over a sequences genetic entity is studied. Key question was whether the starts are distributed uniformly and homogeneously along a sequence, or there exist some spots of the increased local density of the starts. To answer the question, 15 bacterial genomes have been studied. It was found that some genomes exhibit extremely far distribution pattern, from an homogeneity, while others show lower level of the inhomogeneity. The inhomogeneity level was determined through the Kullback-Leibler distance between the real string distribution, and that one bearing the most probable continuations of the shorter strings. © 2019, Springer Nature Switzerland AG.

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Держатели документа:
Institute of Computational Modelling of SB RAS, Akademgorodok, Krasnoyarsk, 660036, Russian Federation
Institute of Fundamental Biology and Biotechnology, Siberian Federal University, Svobodny prosp., 79, Krasnoyarsk, 660049, Russian Federation
Institute of Space Research and Computer Sciences, Siberian Federal University, Kirenskogo str., 26, Krasnoyarsk, 660074, Russian Federation

Доп.точки доступа:
Sadovsky, M.; Kobets, V.; Khodos, G.; Kuzmin, D.; Sharov, V.