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   V30

    MHD-Control of Gas Flow in the Tract Hypersonic Ramjet Engine
[Text] : статья / E. N. Vasilyev, V. A. Derevyanko, A. N. Mierau // The 3rd Workshop on Magneto-Plasma Aerodynamics in Aerospase Applications. - Moscow, 2001. - p. 160-164
ГРНТИ

Аннотация: Nowadays in leading countries of the world active research has been conducted on developing the perspective hypersonic aerospace aircraft. One of the key directions of research on this problem is the development highly efficient hypersonic ramjet engine (HRE). It is known that the efficiency of HRE with supersonic flow velocities in the combustion chamber decreases with the increasing of flight velocities. The basic losses take place in the combustion chamber as firstly the relative losses of working capacity of gas is considerably increasing at the heat supply, secondly because of high speed of the flow the quality of fuel confusion with the air on the bounded length considerably deteriorates and the completeness of combustion declines. The remarks of estimates demonstrate that for this reason the application of HRE is bounded evidently with the Mach numbers of flight that doesn't exceed 11-12. At the same time the thermodynamic estimates demonstrate the considerable reserve on the specific characteristics. This reserve can partly be realized by the reconstruction of the structure of the current using MHD-interaction.

http://icm.krasn.ru/refextra.php?id=2342,
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Держатели документа:
ИВМ СО РАН : 660036, Красноярск, Академгородок, 50, стр.44

Доп.точки доступа:
Derevyanko, V.A.; Деревянко, Валерий Александрович; Mierau, A.N.; Васильев, Евгений Николаевич
   В3
   M66

    Numerical Simulation the Periodic Operating Regime of HRE with MHD Control
[Text]. - Electronic text data (73 Kb)
. - Режим доступа: http://icm.krasn.ru/refextra.php?id=1515. - Электрон. версия печ. публикации . - Режим доступа: http://library.krasn.ru/trudy/2000/1515lab23eng_28.pdf (Полный текст) : статья / A.N. Mierau, V.A. Derevyanko, A.N. Vasilyev. - Electronic text data (73 Kb) // X International Conference on the Methods of Aerophysical Research. - Novosibirsk, 2000. - Part III. - p. 143-149

Аннотация: Nowadays both in Russia and abroad active research has been conducted on developing perspective hypersonic aerospace aircraft. The developing of such aircraft would allow to essentially expand aircraft possibilities and to reduce delivery cost of goods to the near-earth orbit. In many countries of the world there are programs of creation of hypersonic aircraft such as: HOTOL in Great Britain, NASP in USA, HERMES in France. One of key while conducting these projects is the creation of a hypersonic ramjet engine having necessary propulsive, mass and dimensional characteristics with all altitude range and flight velocities of an aircraft. The basic difficulties, in development of such engine types are caused by substantial of deterioration of quality of fuel mixture with an oxidant under supersonic flow velocities in the combustion chamber, which results in decrease of an engine efficiency and deterioration of its propulsion. To increase the efficiency of HRE with the supersonic flow velocity in the combustion chamber the authors offered MHD control of gas flow in the channel HRE based on creation in a stream of local plasma areas with temperature 104 K interacting with an external magnetic field [1], [2]. The work presents investigation results for the structure of non-stationary gas-dynamic flow in the channel HRE with MHD - control. It also describes the calculation of propulsion performance characteristics of the given engine on the basis of mathematical simulation of processes, which take place in the channel of an engine. Thee work objective was the research of non-stationary periodic flow with heat application in the tract HRE with MHD - control on the basis of mathematical modeling of processes which take place in the channel of an engine and the calculation of propulsion performance characteristics of an engine. In the work the model HRE including the air intake, MHD - channel and nozzle was considered. The MHD - channel is made of two flat electrodes and sidewalls from a dielectric. The local constant flow heat permitting to create periodical local plasma areas (T- layer) is provided with the systems of initiation the constant magnetic field in the volume of the channel is ensured with an external magnetic system.

http://icm.krasn.ru/refextra.php?id=1515,
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Держатели документа:
ИВМ СО РАН : 660036, Красноярск, Академгородок, 50, стр.44

Доп.точки доступа:
Derevyanko, V.A.; Деревянко, Валерий Александрович; Vasilyev, A.N.; Васильев А.Н.

    Generation of explicit knowledge from empirical data through pruning of trainable neural networks
[Text]. - Electronic text data (125 Кб)
. - Режим доступа: http://icm.krasn.ru/refextra.php?id=1269. - Электрон. версия печ. публикации . - Режим доступа: http://library.krasn.ru/trudy/1999/1269gorban_IJCNN99Know.pdf (Полный текст) : статья / A.N. Gorban, Ye.M. Mirkes, V.G. Tsaregorodtsev. - Electronic text data (125 Кб) // Proceedings of International Joint Conference on Neural Networks. - Washington, 1999. - p. 436-441
ГРНТИ

Аннотация: This paper presents a generalized technology of extraction of explicit knowledge from data. The main ideas are 1) maximal reduction of network complexity (not only removal of neurons or synapses, but removal all the unnecessary elements and signals and reduction of the complexity of elements), 2) using of adjustable and flexible pruning process (the pruning sequence shouldn't be predetermined - the user should have a possibility to prune network on his own way in order to achieve a desired network structure for the purpose of extraction of rules of desired type and form), and 3) extraction of rules not in predetermined but any desired form. Some considerations and notes about network architecture and training process and applicability of currently developed pruning techniques and rule extraction algorithms are discussed. This technology, being developed by us for more than 10 years, allowed us to create dozens of knowledge-based expert systems.

http://icm.krasn.ru/refextra.php?id=1269,
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Держатели документа:
ИВМ СО РАН : 660036, Красноярск, Академгородок, 50, стр.44

Доп.точки доступа:
Mirkes, Ye.M.; Миркес Е.М.; Tsaregorodtsev, V.G.; Царегородцев, Виктор Геннадьевич; Горбань, Александр Николаевич

    The variable structure algorithm based on L-stable and explicit methods
[Text] : статья / E.A. Novikov // Russian Journal of Numerical Analysis and Mathematical Modelling. - 2012. - Vol. 27, № 3. - p. 243-259, DOI 10.1515/rnam-2012-0014 . - ISSN 0927-6467


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Держатели документа:
ИВМ СО РАН : 660036, Красноярск, Академгородок, 50, стр.44

Доп.точки доступа:
Новиков, Евгений Александрович

    Correlation between Mitochondria Genomes Structure and Taxonom
[Текст] : статья / М. Г. Садовский // Int. symp. on Networks in Bionformatics. - 2011. - p. 17



Доп.точки доступа:
Sadovskii M.G.

    Structure of Almost Layer-Finite Groups
[Текст]. - Electronic text data : статья / V.I. Senashov. - Electronic text data // Advances in Modelling. - 2011. - Vol. 48, Issue 1. - p. 28-38. . - (Series A. General Mathematics) . - ISSN 1258-5769


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Держатели документа:
ИВМ СО РАН : 660036, Красноярск, Академгородок, 50, стр.44

Доп.точки доступа:
Сенашов, Владимир Иванович

    Two-dimensional MHD model of the reconnection diffusion region
[Text] : статья / N.V. Erkaev, V.S. Semenov, H.K. Biernat // Nonlinear Processes in Geophysics. - 2002. - Vol. 9, № 2. - p. 131–138 . - ISSN 1023-5809

Аннотация: Magnetic reconnection is an important process providing a fast conversion of magnetic energy into thermal and kinetic plasma energy. In this concern, a key problem is that of the resistive diffusion region where the reconnec-tion process is initiated. In this paper, the diffusion region is associated with a nonuniform conductivity localized to a small region. The nonsteady resistive incompressible MHD equations are solved numerically for the case of symmetric reconnection of antiparallel magnetic fields. A Petschek type steady-state solution is obtained as a result of time relax-ation of the reconnection layer structure from an arbitrary initial stage. The structure of the diffusion region is studied for various ratios of maximum and minimum values of the plasma resistivity. The effective length of the diffusion re-gion and the reconnection rate are determined as functions of the length scale and the maximum of the resistivity. For suf-ficiently small length scale of the resistivity, the reconnection rate is shown to be consistent with Petschek's formula. By increasing the resistivity length scale and decreasing the re-sistivity maximum, the reconnection layer tends to be wider, and correspondingly, the reconnection rate tends to be more consistent with that of the Parker-Sweet regime.

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http://icm.krasn.ru/refextra.php?id=2434

Держатели документа:
ИВМ СО РАН : 660036, Красноярск, Академгородок, 50, стр.44

Доп.точки доступа:
Semenov, V.S.; Семенов В. С.; Biernat, H.K.; Еркаев, Николай Васильевич

    Rectification effect of a radiation force
[Text] : статья / A.P. Kazantsev, I.V. Krasnov // Journal of the Optical Society of America B. - 1989. - Vol. 6, № 11. - p. 2140-2148DOI: 10.1364/JOSAB.6.002140 . -

Аннотация: A radiation-pressure force, changing only slightly within the wavelength of light (rectification effect), has been shown to arise in interfering fields. In a monochromatic field a rectified force (RF) has the scale of a spontaneous light-pressure force, and it is mainly a vortex one. In a bichromatic field the RF has the order of magnitude of the induced light-pressure force and does saturate in a strong field. The spatial RF structure can be either potential or rotational. The depth of the potential wells generated by the RF can exceed by several orders of magnitude the energy of the atom-field interaction, and it can reach 10 K and larger. A vortex periodic RF results either in regular rotating motion or in a random walk of atoms along the boundaries of elementary cells of the force field. Possible applications of the RF are discussed.

Держатели документа:
ИВМ СО РАН : 660036, Красноярск, Академгородок, 50, стр.44

Доп.точки доступа:
Krasnov, I.V.; Краснов, Игорь Васильевич

    Numerical simulation of supersonic flows in a channel
/ V.V. Shaidurov, G.I. Shchepanovskaya, V.M. Yakubovich // Russ. J. Numer. Anal. Math. Model. - 2012. - Vol. 27, Is. 6. - pp. 585-601, DOI 10.1515/rnam-2012-0034. - Cited References: 18. - The work was supported by the Russian Foundation for Basic Research (11-01-00224) and by the TRISTAM International project. . - ISSN 0927-6467
РУБ Engineering, Multidisciplinary + Mathematics, Applied

Аннотация: An algorithm for numerical solution of Navier-Stokes equations for two-dimensional motion of a viscous heat-conducting gas is proposed in the paper. The discretization of the equations is performed by a combination of the method of trajectories for the substantive derivative and the finite element method with piecewise-bilinear basis functions for other summands. Results of numerical study of the supersonic flow structure are presented for a flat channel in its step expansion zone for a wide range of Mach and Reynolds numbers. Velocity and pressure fields are investigated, the vortex structure of the circulation flow is studied in the domain after the step.


Доп.точки доступа:
Shaidurov, V.V.; Шайдуров, Владимир Викторович; Shchepanovskaya, G.I.; Щепановская, Галина Ивановна; Yakubovich, M.V.; Якубович, Максим Викторович

    Seismic inhomogeneities in the upper mantle beneath the Siberian craton (Meteorite profile)
/ V.D. Suvorov [et al.] // Russian Geology and Geophysics. - 2013. - Vol. 54, Is. 9. - pp. 1108-1120, DOI 10.1016/j.rgg.2013.07.023 . - ISSN 1068-7971

Кл.слова (ненормированные):
Nuclear explosion -- Seismic profile -- Siberian craton -- Upper mantle

Аннотация: The upper-mantle structure was studied from first-arrival data along the Meteorite profile, run using underground nuclear explosions. Unlike the layered, slightly inhomogeneous models in the previous works, emphasis was laid on lateral inhomogeneity at the minimum possible number of abrupt seismic boundaries. We used forward ray tracing of the traveltimes of refracted and overcritical reflected waves. The model obtained is characterized by considerable velocity variations, from 7.7 km/s in the Baikal Rift Zone to 8.0-8.45 km/s beneath the Tunguska syneclise. A layer of increased velocity (up to 8.5-8.6 km/s), 30-80 km thick, is distinguished at the base of seismic lithosphere. The depth of the layer top varies from 120 km in the northern Siberian craton to 210 km in its southeastern framing. It has been shown that, with crustal density anomalies excluded, the reduced gravity field is consistent with the upper-mantle velocity model. В© 2013.

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Доп.точки доступа:
Suvorov, V.D.; Mel'nik, E.A.; Mishen'kina, Z.R.; Pavlov, E.V.; Kochnev, V.A.; Кочнев, Владимир Алексеевич

    Constructing the integral OLAP-model for scientific activities based on FCA
/ T. Penkova, A. Korobko // Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics). - 2013. - Vol. 7828 LNAI: 16th International Conference on Knowledge Engineering, Machine Learning and Lattice Computing with Applications, KES 2012 (10 September 2012 through 12 September 2012, San Sebastian. - P163-170, DOI 10.1007/978-3-642-37343-5_17 . -
Аннотация: In this paper an original approach to analytical decision making support based on on-line analytical processing of multidimensional data is suggested. According to Dr. Codd's rules, the effectiveness of data analysis significantly depends on the data accessibility and transparency of an analytical model of domain. The method of constructing a conceptual OLAP-model as an integral analytical model of the domain is proposed. The method is illustrated by the example of the scientific activities domain. The integral analytical model includes all possible combinations of analyzed objects and gives them the opportunity to be manipulated ad-hoc. The suggested method consists in a formal concept analysis of measures and dimensions based on an expert knowledge about the structure of analyzing objects and their comparability. As a result, conceptual OLAP-model is represented as a concept lattice of multidimensional cubes. Concept lattice features allow the decision maker to discover the nonstandard analytical dependencies on the set of all actual measures and dimensions of the scientific activities domain. Conceptual OLAP-model implementation allows user makes better decisions based on on-line analytical processing of the scientific activity indicators. В© 2013 Springer-Verlag.

Scopus


Доп.точки доступа:
Penkova, T.; Пенькова, Татьяна Геннадьевна; Korobko, A.; Коробко, Анна Владимировна

    Method of constructing the integral OLAP-model based on formal concept analysis
/ T. Penkova, A. Korobko // Frontiers in Artificial Intelligence and Applications. - 2012. - Vol. 243. - pp. 219-227, DOI 10.3233/978-1-61499-105-2-219 . -

Кл.слова (ненормированные):
Formal concept analysis -- Integral OLAP-model -- On-line analytical processing

Аннотация: In this paper a new approach to analytical decision making support based on on-line analytical processing of multidimensional data is suggested. The effectiveness of data analysis depends largely on the data accessibility and transparency of an analytical model of domain. As usual, analytical model of domain is a set of OLAP-models for solving particular problems. The method of constructing a conceptual OLAP-model as an integral analytical model of the domain is proposed. The integral analytical model includes all possible combinations of analyzed objects and gives them the opportunity to be manipulated ad-hoc. The suggested method consists in a formal concept analysis of measures and dimensions based on an expert knowledge about the structure of analyzing objects and their comparability. As a result, conceptual OLAP-model is represented as a concept lattice of multidimensional cubes. Concept lattice features allow the decision maker to discover the nonstandard analytical dependencies on the set of all actual analyzing objects. Conceptual OLAP-model implementation improves the effectiveness of decision making support based on on-line analytical processing of multidimensional data. В© 2012 The authors and IOS Press. All rights reserved.

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Доп.точки доступа:
Penkova, T.; Пенькова, Татьяна Геннадьевна; Korobko, A.; Коробко, Анна Владимировна

    Comparative analysis of phytoplankton of the Baikal and Khanka lakes
[Text] / L.A. Shchur, N.A. Bondarenko // Hydrobiological Journal. - 2012. - Vol. 48, Is. 3. - pp. 14-23, DOI 10.1615/HydrobJ.v48.i3.20 . - ISSN 0018-8166
Аннотация: The structure and production potential of phytoplankton were studied in two large lakes of Asia, including the Baikal and Khanka lakes differing in their hydrological conditions. It has been found that the studied algae flora is saturated. The environmental conditions in the lakes are rather favorable to the development of algae. The functional characteristics of phytoplankton depended mainly on the regime of illumination, dimensional composition of algae, intensity of their development, vegetation stage, and also on the peculiarities of dominant forms biology. В© 2012 Begell House, Inc.

Scopus


Доп.точки доступа:
Shchur, L.A.; Щур, Людмила Александровна; Bondarenko, N.A.

    Numerical modeling of vertical stratification of Lake Shira in summer
[Text] / P.V. Belolipetsky [et al.] // Aquat. Ecol. - 2010. - Vol. 44, Is. 3. - pp. 561-570, DOI 10.1007/s10452-010-9330-z. - Cited References: 35. - The study was financially supported by the Netherlands Organization for Scientific Research (NWO), Grant 047.011.2004.030, RFBR, Grant 05-05-89002; RFBR, Grant 07-01-00153; Multidisciplinary integration project of SB RAS No. 95. . - ISSN 1386-2588
РУБ Ecology + Limnology + Marine & Freshwater Biology

Аннотация: A one-dimensional numerical model and a two-dimensional numerical model of the hydrodynamic and thermal structure of Lake Shira during summer have been developed, with several original physical and numerical features. These models are well suited to simulate the formation and dynamics of vertical stratification and provide a basis for an ecological water-quality model of the lake. They allow for the quantification of the vertical mixing processes that govern not only the thermal structure but also the nutrient exchange, and more generally, the exchange of dissolved and particulate matter between different parts of the lake. The outcome of the calculations has been compared with the field data on vertical temperature and salinity distributions in Lake Shira. Lake Shira is meromictic and exhibits very stable annual stratification. The stratification is so stable because of the high salinity of the water. If the water in Lake Shira were fresh and other parameters (depth, volume, and meteorology) were the same, as now, the lake would be mixed in autumn. Using the newly developed models and using common meteorological parameters, we conclude that Lake Shira will remain stratified in autumn as long as the average salinity is higher than 3%.


Доп.точки доступа:
Belolipetsky, P.V.; Белолипецкий, Павел Викторович; Belolipetskii, V.M.; Белолипецкий, Виктор Михайлович; Genova, S.N.; Генова, Светлана Николаевна; Mooij, W.M.

    A one-dimensional model of vertical stratification of Lake Shira focussed on winter conditions and ice cover
[Text] / S.N. Genova [et al.] // Aquat. Ecol. - 2010. - Vol. 44, Is. 3. - pp. 571-584, DOI 10.1007/s10452-010-9327-7. - Cited References: 26. - The study was financially supported by the Netherlands Organization for Scientific Research (NOW), Grant 047.011.2004.030; RFBR, Grant 05-05-89002; RFBR, Grant 07-01-00153; Multidisciplinary integration project of SB RAS No. 95. . - ISSN 1386-2588
РУБ Ecology + Limnology + Marine & Freshwater Biology
Рубрики:
SEA ICE
   BACTERIA

   DEPTH

Кл.слова (ненормированные):
Convective mixed layer -- Ice formation -- Ice melting -- Simplified model -- Winter profiles

Аннотация: In meromictic lakes such as Lake Shira, horizontal inhomogeneity is small in comparison with vertical gradients. To determine the vertical distribution of temperature, salinity, and density of water in a deep zone of a Lake Shira, or other saline lakes, a one-dimensional (in vertical direction) mathematical model is presented. A special feature of this model is that it takes into account the process of ice formation. The model of ice formation is based on the one-phase Stefan problem with the linear temperature distribution in the solid phase. A convective mixed layer is formed under an ice cover due to salt extraction in the ice formation process. To obtain analytical solutions for the vertical distribution of temperature, salinity, and density of water, we use a scheme of vertical structure in the form of several layers. In spring, the ice melts as top and bottom. These processes are taken into account in the model. The calculated profiles of salinity and temperature of Shira Lake are in good agreement with field measurement data for each season. Additionally, we focussed on the redox zone, which is the zone in which the aerobic layers of a water column meet the anaerobic ones. Hyperactivity of plankton communities is observed in this zone in lakes with hydrogen sulphide monimolimnion, and Lake Shira is among them. The location of the redox zone in the lake, which is estimated from field measurements, coincides with a sharp increase in density (the pycnocline) during autumn and winter. During spring and summer, the redox zone is deeper than the pycnocline. The location of pycnocline calculated with the hydro physical model is in good agreement with field measurement data.


Доп.точки доступа:
Genova, S.N.; Генова, Светлана Николаевна; Belolipetskii, V.M.; Белолипецкий, Виктор Михайлович; Rogozin, D.Y.; Degermendzhy, A.G.; Mooij, W.M.

    Analysis of energy balance of the arc discharge limited by walls
[Text] / E.N. Vasiliev // Thermophys. Aeromechanics. - 2010. - Vol. 17, Is. 3. - pp. 411-418, DOI 10.1134/S0869864310030121. - Cited References: 13 . - ISSN 0869-8643
РУБ Thermodynamics + Mechanics

Кл.слова (ненормированные):
arc discharge -- heat exchange -- radiation regime -- channel model

Аннотация: The modeling of the formation of the equilibrium arc discharge structure in the axisymmetric formulation was carried out in a wide range of the values of current and radius. The boundary separating the radiation and heat-conducting regimes of discharge combustion was determined from computed data. The influence of energy mechanisms on the structure of the discharge was analysed, and a channel model was proposed for computing its parameters in the radiation regime.


Доп.точки доступа:
Vasiliev, E.N.; Васильев, Евгений Николаевич

    Hall magnetohydrodynamic effects for current sheet flapping oscillations related to the magnetic double gradient mechanism
[Text] / N.V. Erkaev, V.S. Semenov, H.K. Biernat // Phys. Plasmas. - 2010. - Vol. 17, Is. 6. - Ст. 60703, DOI 10.1063/1.3439687. - Cited References: 15. - This work is supported by RFBR (Grant Nos. N 07-05-00776-a and N 09-05-91000-ANF_a), and by Program No. 16 of RAS. Additional support is due to the Austrian "Fonds zur Forderung der wissenschaftlichen Forschung" under Project No. I 193-N16 and the "Verwaltungsstelle fur Auslandsbeziehungen" of the Austrian Academy of Sciences. . - ISSN 1070-664X
РУБ Physics, Fluids & Plasmas

Аннотация: Hall magnetohydrodynamic model is investigated for current sheet flapping oscillations, which implies a gradient of the normal magnetic field component. For the initial undisturbed current sheet structure, the normal magnetic field component is assumed to have a weak linear variation. The profile of the electric current velocity is described by hyperbolic functions with a maximum at the center of the current sheet. In the framework of this model, eigenfrequencies are calculated as functions of the wave number for the "kink" and "sausage" flapping wave modes. Because of the Hall effects, the flapping eigenfrequency is larger for the waves propagating along the electric current, and it is smaller for the opposite wave propagation with respect to the current. The asymmetry of the flapping wave propagation, caused by Hall effects, is pronounced stronger for thinner current sheets. This is due to the Doppler effect related to the electric current velocity. (C) 2010 American Institute of Physics. [doi:10.1063/1.3439687]


Доп.точки доступа:
Erkaev, N.V.; Еркаев, Николай Васильевич; Semenov, V.S.; Biernat, H.K.

    Some new approaches to solving Navier-Stokes equations for viscous heat-conducting gas
/ V. V. Shaydurov, G. I. Shchepanovskaya, M. V. Yakubovich // Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics). - 2013. - Vol. 8236 LNCS: 5th International Conference on Numerical Analysis and Applications, NAA 2012 (15 June 2013 through 20 June 2013, Lozenetz. - P122-131, DOI 10.1007/978-3-642-41515-9_11 . -

Кл.слова (ненормированные):
finite element method -- Navier-Stokes equations -- numerical modeling -- trajectories -- viscous heat-conducting gas

Аннотация: The algorithm for numerical solving the Navier-Stokes equations for two-dimensional motion for viscous heat-conducting gas is proposed. The discretization of equations is performed by a combination of a special version of the trajectory method for a substantial derivative and the finite element method with piecewise bilinear basis functions for other terms. The results of numerical studies of the structure of a supersonic flow in a plane channel with an obstacle for a wide range of Mach numbers and Reynolds numbers are presented. Velocity and pressure fields are investigated, and the vortex structure of flow is studied in the circulation area of the obstacle. В© 2013 Springer-Verlag.

Scopus

Держатели документа:
Institute of Computational Modeling, Siberian Branch, Russian Academy of Science, Krasnoyarsk, Russian Federation
Beihang University, Beijing, China

Доп.точки доступа:
Shaydurov, V.V.; Shchepanovskaya, G.I.; Yakubovich, M.V.

    Classification of Symbol Sequences over Their Frequency Dictionaries: Towards the Connection between Structure and Natural Taxonomy
/ A.N. Gorban, T.G. Popova, M.G. Sadovsky // Open Systems and Information Dynamics. - 2000. - Vol. 7, Is. 1. - P1-17 . - ISSN 1230-1612

Аннотация: The classifications of bacterial 16S RNA sequences developed over the real and transformed frequency dictionaries have been studied. Two sequences are considered to be close, when their frequency dictionaries are close in Euclidean metrics. A procedure to transform a dictionary is proposed that makes clear some features of the information pattern of a symbol sequence. A comparative study of classifications developed over real frequency dictionaries vs. the transformed ones has been carried out. A correlation between information patterns of nucleotide sequences and taxonomy of the bearer of the sequence was found. The sites with high information value are found to be the main factors of the difference between the classes in a classification. The classification of nucleotide sequences developed over real frequency dictionaries of thickness 3 reveals the best correlation to a gender of bacteria. A set of sequences of the same gender is included entirely into one class, as a rule, and exclusions occur rarely. A hierarchical classification yields one or two taxonomy groups on each level of classification. An unexpectedly often, or unexpectedly rare occurrence of some sites within a sequence makes a basic difference between the structure patterns of the classes yielded; a number of those sites is not to large. Further investigations are necessary in order to campare the sites revealed with those determined due to other methodology.

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Доп.точки доступа:
Gorban, A.N.; Горбань, Александр Николаевич; Popova, T.G.; Попова Т.Г.; Sadovsky, M.G.; Садовский, Михаил Георгиевич

    XUV-Exposed, Non-Hydrostatic Hydrogen-Rich Upper Atmospheres of Terrestrial Planets. Part I: Atmospheric Expansion and Thermal Escape
[Text] / N. V. Erkaev [et al.] // Astrobiology. - 2013. - Vol. 13, Is. 11. - P1011-1029, DOI 10.1089/ast.2012.0957. - Cited References: 92. - M. Gudel, K. G. Kislyakova, M. L. Khodachenko, and H. Lammer acknowledge support by the FWF NFN project S116 601-N16 "Pathways to Habitability: From Disks to Active Stars, Planets and Life" and the related FWF NFN subprojects S116 604-N16 "Radiation & Wind Evolution from T Tauri Phase to ZAMS and Beyond," S116 606-N16 "Magnetospheric Electrodynamics of Exoplanets," S116 607-N16 "Particle/Radiative Interactions with Upper Atmospheres of Planetary Bodies under Extreme Stellar Conditions." K. G. Kislyakova, Yu. N. Kulikov, H. Lammer, and P. Odert thank also the Helmholtz Alliance project "Planetary Evolution and Life." P. Odert and A. Hanslmeier also acknowledge support from the FWF project P22950-N16. The authors also acknowledge support from the EU FP7 project IMPEx (No. 262863) and the EUROPLANET-RI projects, JRA3/EMDAF and the Na2 science WG5. The authors thank the International Space Science Institute (ISSI) in Bern and the ISSI team "Characterizing stellar and exoplanetary environments." N. V. Erkaev acknowledges support by the RFBR grant No 12-05-00152-a. Finally, the authors thank referee Tian Feng, from the Tsinghua University, Beijing, China, for suggestions and recommendations that helped to improve the work. . - 19. - ISSN 1531-1074
РУБ Astronomy & Astrophysics + Biology + Geosciences, Multidisciplinary

Аннотация: The recently discovered low-density super-Earths Kepler-11b, Kepler-11f, Kepler-11d, Kepler-11e, and planets such as GJ 1214b represent the most likely known planets that are surrounded by dense H/He envelopes or contain deep H2O oceans also surrounded by dense hydrogen envelopes. Although these super-Earths are orbiting relatively close to their host stars, they have not lost their captured nebula-based hydrogen-rich or degassed volatile-rich steam protoatmospheres. Thus, it is interesting to estimate the maximum possible amount of atmospheric hydrogen loss from a terrestrial planet orbiting within the habitable zone of late main sequence host stars. For studying the thermosphere structure and escape, we apply a 1-D hydrodynamic upper atmosphere model that solves the equations of mass, momentum, and energy conservation for a planet with the mass and size of Earth and for a super-Earth with a size of 2 R-Earth and a mass of 10 M-Earth. We calculate volume heating rates by the stellar soft X-ray and extreme ultraviolet radiation (XUV) and expansion of the upper atmosphere, its temperature, density, and velocity structure and related thermal escape rates during the planet's lifetime. Moreover, we investigate under which conditions both planets enter the blow-off escape regime and may therefore experience loss rates that are close to the energy-limited escape. Finally, we discuss the results in the context of atmospheric evolution and implications for habitability of terrestrial planets in general. Key Words: Stellar activityLow-mass starsEarly atmospheresEarth-like exoplanetsEnergetic neutral atomsIon escapeHabitability. Astrobiology 13, 1011-1029.

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Scopus

Держатели документа:
[Erkaev, Nikolai V.] Russian Acad Sci, Siberian Div, Inst Computat Modelling, Krasnoyarsk 660036, Russia
[Erkaev, Nikolai V.] Siberian Fed Univ, Krasnoyarsk, Russia
[Lammer, Helmut
Odert, Petra
Kislyakova, Kristina G.
Khodachenko, Maxim L.
Biernat, Helfried] Austrian Acad Sci, Space Res Inst, A-8010 Graz, Austria
[Odert, Petra
Kislyakova, Kristina G.
Hanslmeier, Arnold] Graz Univ, Inst Phys, Graz, Austria
[Kulikov, Yuri N.] Russian Acad Sci, Polar Geophys Inst, Murmansk, Russia
[Khodachenko, Maxim L.] Moscow MV Lomonosov State Univ, Inst Nucl Phys, Moscow, Russia
[Guedel, Manuel] Univ Vienna, Inst Astrophys, A-1010 Vienna, Austria
ИВМ СО РАН

Доп.точки доступа:
Erkaev, N.V.; Еркаев, Николай Васильевич; Lammer, H.; Odert, P.; Kulikov, Y.N.; Kislyakova, K.G.; Khodachenko, M.L.; Gudel, M.; Hanslmeier, A.; Biernat, H.K.; FWF NFN project [S116 601-N16, S116 604-N16, S116 606-N16, S116 607-N16]; FWF project [P22950-N16]; EU [262863]; EUROPLANET-RI projects; JRA3/EMDAF; Na2 science WG5; RFBR [12-05-00152-a]