[Electronic resource]. - Electronic data
. - Режим доступа: http://icm.krasn.ru/refextra.php?id=2102. - Электрон. версия печ. публикации : научное издание / Gorban A.N. Zinovyev A.Y. - Electronic data // Institut des Hautes Etudes Scientifiques Preprint. IHES M/01/36. - 2001
Перевод заглавия: Визуализация данных с помощью метода упругих карт и его приложения в геномике, экономике и социологии
Аннотация: Technology of data visualization and data modeling is suggested. The basic of the technology is original idea of elastic net and methods of its construction and application. A short review of relevant methods has been made. The methods proposed are illustrated by applying them to the real biological, economical, sociological datasets and to some model data distributions.
http://icm.krasn.ru/refextra.php?id=2102
Доп.точки доступа:
Zinovyev, A.Y.; Зиновьев, Андрей Юрьевич; Горбань, Александр Николаевич
Труды сотрудников ИВМ СО РАН
w10=
Найдено документов в текущей БД: 470
З973.2-018
G65
G65
Visualization of data by method of elastic maps and its applications in genomics,economics and sociology
В3
G65
G65
Recovering data gaps through neural network methods
[Text] : статья / A.N. Gorban, A. Rossiev, N. Makarenko, Y. Kuandykov, V. Dergachev // International Journal of Geomagnetism and Aeronomy. - 2002. - Vol. 3, № 2. - p. 191–197
Аннотация: A new method is presented to recover the lost data in geophysical time series. It is clear that gaps in data are a substantial problem in obtaining correct outcomes about phenomenon in time series processing. Moreover, using the data with irregular coarse steps results in the loss of prime information during analysis. We suggest an approach to solving these problems, that is based on the idea of modeling the data with the help of small-dimension manifolds, and it is implemented with the help of a neural network. We use this approach on real data and show its proper use for analyzing time series of cosmogenic isotopes. In addition, multifractal analysis was applied to the recovered 14C concentration in the Earth's atmosphere.
http://icm.krasn.ru/refextra.php?id=2790,
http://ijga.agu.org/v03/gai01384/gai01384.pdf,
Полный текст
Держатели документа:
ИВМ СО РАН : 660036, Красноярск, Академгородок, 50, стр.44
Доп.точки доступа:
Rossiev, A.; Россиев, Алексей Анатольевич; Makarenko, N.; Макаренко Н.; Kuandykov, Y.; Dergachev, V.; Горбань, Александр Николаевич
Аннотация: A new method is presented to recover the lost data in geophysical time series. It is clear that gaps in data are a substantial problem in obtaining correct outcomes about phenomenon in time series processing. Moreover, using the data with irregular coarse steps results in the loss of prime information during analysis. We suggest an approach to solving these problems, that is based on the idea of modeling the data with the help of small-dimension manifolds, and it is implemented with the help of a neural network. We use this approach on real data and show its proper use for analyzing time series of cosmogenic isotopes. In addition, multifractal analysis was applied to the recovered 14C concentration in the Earth's atmosphere.
http://icm.krasn.ru/refextra.php?id=2790,
http://ijga.agu.org/v03/gai01384/gai01384.pdf,
Полный текст
Держатели документа:
ИВМ СО РАН : 660036, Красноярск, Академгородок, 50, стр.44
Доп.точки доступа:
Rossiev, A.; Россиев, Алексей Анатольевич; Makarenko, N.; Макаренко Н.; Kuandykov, Y.; Dergachev, V.; Горбань, Александр Николаевич
В3
M66
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,
Полный текст
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.
. - 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,
Полный текст
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.
Numerical Modeling of Distribution of a Smoke in Increased Storey Buildings
[Текст] : научное издание / L. P. Kamenshchikov, V. I. Bykov, S. P. Amel chugov // Proc. of the Second Int. Seminar "Fire and Explosion of Substances and Venting of Deflagratins / ed. V. Molkov. - Moscow : All-Russian Researh Institute for Fire Protection. - С. 650-659
Доп.точки доступа:
Bykov, V.I.; Быков, Валерий Иванович; Amel Сhugov, S.P.; Каменщиков, Леонид Петрович
Доп.точки доступа:
Bykov, V.I.; Быков, Валерий Иванович; Amel Сhugov, S.P.; Каменщиков, Леонид Петрович
В14
N89
N89
Methods for solution of stiff problems, hybrid systems and applications
[Text] : монография / E. A. Novikov, Yu. V. Shornikov, B. U. Uatay ; Kazakh-British Technical University. - Almaty : KBTU, 2010. - 157 p. : il. - Библиогр.: с. 144. - ISBN 978-601-269-009-5 : Б. ц.
ББК В14
Аннотация: This monograph covers the problem of modeling of numerical methods for solving of Cauchy problem for stiff systems of ordinary differential equations. Particular attention will be paid to notion and classification of hybrid systems. Capabilities of instrumental environment of computerizedanalysis for hybrid systems will be described. This book is intended for individuals who are involved in modeling of physical, chemical, biological and other processes
Доп.точки доступа:
Shornikov, Yu.V.; Шорников Ю.В.; Uatay, B.U.; Новиков, Евгений Александрович
Свободных экз. нет
| УДК |
Аннотация: This monograph covers the problem of modeling of numerical methods for solving of Cauchy problem for stiff systems of ordinary differential equations. Particular attention will be paid to notion and classification of hybrid systems. Capabilities of instrumental environment of computerizedanalysis for hybrid systems will be described. This book is intended for individuals who are involved in modeling of physical, chemical, biological and other processes
Доп.точки доступа:
Shornikov, Yu.V.; Шорников Ю.В.; Uatay, B.U.; Новиков, Евгений Александрович
Свободных экз. нет
Numerical modeling of operation of high-pressure detonation MHD-generator
[Text] : статья / V.V. Derevyanko // Thermophysics and Aeromechanics. - 2001. - Vol. 8, № 3
Аннотация: The numerical modeling of the operation of a detonation MHD generator with T-layer has been performed at large pressures in the duct. It is shown that the radiation absorption inside the T-layer leads to a considerable variation of the layer characteristics, increase in the specific power and generator efficiency.
Полный текст в авторской редакции
Держатели документа:
ИВМ СО РАН : 660036, Красноярск, Академгородок, 50, стр.44
Доп.точки доступа:
Деревянко, Виктор Валерьевич
Аннотация: The numerical modeling of the operation of a detonation MHD generator with T-layer has been performed at large pressures in the duct. It is shown that the radiation absorption inside the T-layer leads to a considerable variation of the layer characteristics, increase in the specific power and generator efficiency.
Полный текст в авторской редакции
Держатели документа:
ИВМ СО РАН : 660036, Красноярск, Академгородок, 50, стр.44
Доп.точки доступа:
Деревянко, Виктор Валерьевич
Method of Assessment of Human-Induced Area Risks and Creation of Risk Map Using Geoinformation Systems
[Text] : статья / Yu.I. Shokin, V.V. Moskvichev, V.V. Nicheporchuk // Vulnerability, Uncertainty, and Risk: Analysis, Modeling, and Management. Proceedings of The First International Conference on Vulnerability and Risk Analysis and Management (ICVRAM 2011) and The Fifth International Symposium on Uncertainty Modeling and Analysis (ISUMA 2011). - Reston : ASCE, 2011. - p. 442-449, DOI 10.1061/41170(400)54
. - ISBN 978-0-7844-1170-4
Полный текст
Держатели документа:
ИВМ СО РАН : 660036, Красноярск, Академгородок, 50, стр.44
Доп.точки доступа:
Moskvichev, V.V.; Москвичев, Владимир Викторович; Nicheporchuk, V.V.; Ничепорчук, Валерий Васильевич; Шокин, Юрий Иванович; International Conference on Vulnerability and Risk Analysis and Management(I ; April 11-13, 2011 ; Hyattsville); International Symposium on Uncertainty Modeling and Analysis(V ; April 11-13, 2011 ; Hyattsville)
Полный текст
Держатели документа:
ИВМ СО РАН : 660036, Красноярск, Академгородок, 50, стр.44
Доп.точки доступа:
Moskvichev, V.V.; Москвичев, Владимир Викторович; Nicheporchuk, V.V.; Ничепорчук, Валерий Васильевич; Шокин, Юрий Иванович; International Conference on Vulnerability and Risk Analysis and Management(I ; April 11-13, 2011 ; Hyattsville); International Symposium on Uncertainty Modeling and Analysis(V ; April 11-13, 2011 ; Hyattsville)
В25
S12
S12
Mathematical Modeling in Mechanics of Granular Materials
[Текст] : монография / O. Sadovskaya, V. Sadovskii. - Berlin ; Heidelberg : Springer-Verlag, 2012. - 390 p. : il. - (Advanced Structured Materials, ISSN 1869-8433 ; vol. 21), ISSN 1869-8441 (electronic)). - Bibliogr. at the end of the chapters. - ISBN 978-3-642-29052-7. - ISBN 978-3-642-29053-4 (eBook) : Б. ц.
ББК В25
Аннотация: This monograph contains original results in the field of mathematical and numerical modeling of machanical behavior of granular materials and materials with different strengths. It proposes new models helping to define zones of the strain localization. The book shows how to analyze processes of the propogation of elastic and elastic-plastic waves in loosened materials, and constructs models of mixed type, describing the flow of granular materials in the presence of quasi-static deformation zones. In a last part? the book studies a numerical realization of the models on multiprocessor computer systems. The book is intended for scientific researchers, lecturers of universities, postgraduates and senior students, who specialize in the field of the deformable materials mechanics, mathematical modeling and adjacent field of applied and calculus mathematics
Полный текст на сайте издательства
Доп.точки доступа:
Sadovskii, V.M.; Садовский, Владимир Михайлович; Садовская, Оксана Викторовна
Экземпляры всего: 1
ЗФ (1)
Свободны: ЗФ (1)
Аннотация: This monograph contains original results in the field of mathematical and numerical modeling of machanical behavior of granular materials and materials with different strengths. It proposes new models helping to define zones of the strain localization. The book shows how to analyze processes of the propogation of elastic and elastic-plastic waves in loosened materials, and constructs models of mixed type, describing the flow of granular materials in the presence of quasi-static deformation zones. In a last part? the book studies a numerical realization of the models on multiprocessor computer systems. The book is intended for scientific researchers, lecturers of universities, postgraduates and senior students, who specialize in the field of the deformable materials mechanics, mathematical modeling and adjacent field of applied and calculus mathematics
Полный текст на сайте издательства
Доп.точки доступа:
Sadovskii, V.M.; Садовский, Владимир Михайлович; Садовская, Оксана Викторовна
Экземпляры всего: 1
ЗФ (1)
Свободны: ЗФ (1)
The numerical modeling of one-dimensional motion of viscous heat-conductive gas
[Текст] : материалы конференции / Г.И. Щепановская // Материалы XV Международной научной конференции «Решетневские чтения». - Красноярск : СибГАУ, 2011. - С. 525
Доп.точки доступа:
Shchepanovskaya G.I.
Доп.точки доступа:
Shchepanovskaya G.I.
The numerical solution of data assimilation problem for shallow water equations
[Text] : статья / E. D. Karepova, V. V. Shaidurov, E. Dementyeva // Int. J. of Num. Analysis and Modeling, Series B.Quantum Chemistry. - 2011. - Vol. 2, № 2-3. - p. 167-182
Полный текст
Доп.точки доступа:
Shaidurov, V.V.; Шайдуров, Владимир Викторович; Dementyeva, E.V.; Дементьева, Екатерина Васильевна; Карепова, Евгения Дмитриевна
Полный текст
Доп.точки доступа:
Shaidurov, V.V.; Шайдуров, Владимир Викторович; Dementyeva, E.V.; Дементьева, Екатерина Васильевна; Карепова, Евгения Дмитриевна
The energy method for constructing time-harmonic solutions to the maxwell equations
[Text] : статья / V.V. Denisenko // Siberian mathematical journal. - 2011. - Vol. 52, № 2. - p. 207-221DOI 10.1134/S0037446611020030
. -
Аннотация: We propose some minimum principle for an energy functional in an elliptic boundary value problem that arises in constructing time-harmonic solutions to the Maxwell equations. We suggest the potentials other than the vector and scalar potentials, used in the mathematical modeling of electromagnetic fields since the operators of traditional problems are not sign definite, which complicates constructions of iterative solution methods. We consider the problem in a parallelepiped whose boundary is ideally conducting. For nonresonant frequencies we prove that the operator of the boundary value problem is positive definite, propose a minimum principle for a quadratic energy functional, and prove the existence and uniqueness of generalized solutions.
Полный текст,
Полный текст на сайте журнала
Держатели документа:
ИВМ СО РАН : 660036, Красноярск, Академгородок, 50, стр.44
Доп.точки доступа:
Денисенко, Валерий Васильевич
Аннотация: We propose some minimum principle for an energy functional in an elliptic boundary value problem that arises in constructing time-harmonic solutions to the Maxwell equations. We suggest the potentials other than the vector and scalar potentials, used in the mathematical modeling of electromagnetic fields since the operators of traditional problems are not sign definite, which complicates constructions of iterative solution methods. We consider the problem in a parallelepiped whose boundary is ideally conducting. For nonresonant frequencies we prove that the operator of the boundary value problem is positive definite, propose a minimum principle for a quadratic energy functional, and prove the existence and uniqueness of generalized solutions.
Полный текст,
Полный текст на сайте журнала
Держатели документа:
ИВМ СО РАН : 660036, Красноярск, Академгородок, 50, стр.44
Доп.точки доступа:
Денисенко, Валерий Васильевич
Numerical solution of dynamic problems in couple-stressed continuum on multiprocessor computer systems
[Text] : статья / V.M. Sadovsky, O.V. Sadovskaya, M.P. Varygina // International Journal of Numerical Analysis and Modeling, Series B. - 2011. - № 2-3. - p. 215-230
Полный текст
Держатели документа:
ИВМ СО РАН : 660036, Красноярск, Академгородок, 50, стр.44
Доп.точки доступа:
Sadovskaya, O.V.; Садовская, Оксана Викторовна; Varygina, M.P.; Варыгина, Мария Петровна; Садовский, Владимир Михайлович
Полный текст
Держатели документа:
ИВМ СО РАН : 660036, Красноярск, Академгородок, 50, стр.44
Доп.точки доступа:
Sadovskaya, O.V.; Садовская, Оксана Викторовна; Varygina, M.P.; Варыгина, Мария Петровна; Садовский, Владимир Михайлович
Mathematical modeling of mechanical properties of structural steels
[Text] : статья / G.G. Krushenko // Вестник СибГАУ. - 2012. - Вып. 2(42). - p. 135-136
Перевод заглавия: Математическое моделирование механических свойств конструкционных сталей
Кл.слова (ненормированные):
structural steels -- mathematical modeling -- mechanical properties -- конструкционные стали -- механические свойства -- математическое моделирование
Полный текст на сайте журнала,
Полный текст
Держатели документа:
ИВМ СО РАН : 660036, Красноярск, Академгородок, 50, стр.44
Доп.точки доступа:
Крушенко, Генрих Гаврилович
Перевод заглавия: Математическое моделирование механических свойств конструкционных сталей
Кл.слова (ненормированные):
structural steels -- mathematical modeling -- mechanical properties -- конструкционные стали -- механические свойства -- математическое моделирование
Полный текст на сайте журнала,
Полный текст
Держатели документа:
ИВМ СО РАН : 660036, Красноярск, Академгородок, 50, стр.44
Доп.точки доступа:
Крушенко, Генрих Гаврилович
The numerical modeling of a cesium cyclein the upper atmosphere by an l-stable method of second-order accuracy
[Текст] : статья / A.E. Novikov, E.A. Novikov // Вестник СибГАУ. - 2009. - Вып. 5(26). - С. 17-20
Кл.слова (ненормированные):
accuracy control -- L-stable method -- stiff problem -- cesium cycle -- chemical kinetics
Аннотация: An algorithm of right-hand side and Jacobian formation of differential equations of chemical kinetics is described. Numerical simulation of the cesium cycle in the upper atmosphere is conducted by means of the L-stable method of the second order of accuracy with the control accuracy. The results of the computation are presented.
Полный текст на сайте журнала
Доп.точки доступа:
Novikov, E.A.; Новиков, Евгений Александрович
Кл.слова (ненормированные):
accuracy control -- L-stable method -- stiff problem -- cesium cycle -- chemical kinetics
Аннотация: An algorithm of right-hand side and Jacobian formation of differential equations of chemical kinetics is described. Numerical simulation of the cesium cycle in the upper atmosphere is conducted by means of the L-stable method of the second order of accuracy with the control accuracy. The results of the computation are presented.
Полный текст на сайте журнала
Доп.точки доступа:
Novikov, E.A.; Новиков, Евгений Александрович
В25
A55
A55
Mathematical Models of Convection
[Text] : монография / V.K. Andreev, Y.A. Gaponenko, O.N. Goncharova, V.V. Pukhnachev. - Berlin [etc.] : Walter de Gruyter, 2012. - XV, 417 p. - (De Gruyter Studies in Mathematical Physics ; 5). - Библиогр.: с. 401-414. - Указ.: с. 415-420. - ISBN 978-3110258141 : Б. ц. - DOI 10.1515/9783110258592
Рубрики:
Natural Sciences--Physics--Theoretical Physics--Mathematical Physics
Mathematics--Applied Mathematics
Кл.слова (ненормированные):
Convection -- Fluid Dynamics -- Heat Transfer Theory -- Mathematical Modeling
Аннотация: Phenomena of convection are abundant in nature as well as in industry. This volume addresses the subject of convection from the point of view of both, theory and application. While the first three chapters provide a refresher on fluid dynamics and heat transfer theory, the rest of the book describes the modern developments in theory. Thus it brings the reader to the "front" of the modern research. This monograph provides the theoretical foundation on a topic relevant to metallurgy, ecology, meteorology, geo-and astrophysics, aerospace industry, chemistry, crystal physics, and many other fields
Текст на сайте издателя
Доп.точки доступа:
Gaponenko, Y.A.; Гапоненко, Юрий Анатольевич; Goncharova, O.N.; Гончарова, Ольга Николаевна; Pukhnachev, V.V.; Пухначев, Владислав Васильевич; Андреев, Виктор Константинович
Свободных экз. нет
Рубрики:
Natural Sciences--Physics--Theoretical Physics--Mathematical Physics
Mathematics--Applied Mathematics
Кл.слова (ненормированные):
Convection -- Fluid Dynamics -- Heat Transfer Theory -- Mathematical Modeling
Аннотация: Phenomena of convection are abundant in nature as well as in industry. This volume addresses the subject of convection from the point of view of both, theory and application. While the first three chapters provide a refresher on fluid dynamics and heat transfer theory, the rest of the book describes the modern developments in theory. Thus it brings the reader to the "front" of the modern research. This monograph provides the theoretical foundation on a topic relevant to metallurgy, ecology, meteorology, geo-and astrophysics, aerospace industry, chemistry, crystal physics, and many other fields
Текст на сайте издателя
Доп.точки доступа:
Gaponenko, Y.A.; Гапоненко, Юрий Анатольевич; Goncharova, O.N.; Гончарова, Ольга Николаевна; Pukhnachev, V.V.; Пухначев, Владислав Васильевич; Андреев, Виктор Константинович
Свободных экз. нет
Group classification for equations of thermodiffusion in binary mixture
/ I.V. Stepanova // Commun. Nonlinear Sci. Numer. Simul. - 2013. - Vol. 18, Is. 6. - P1341-1346, DOI 10.1016/j.cnsns.2012.10.013. - Cited References: 14. - Author thanks Prof. V.K. Andreev for formulation of the problem and attention to the work. This work is supported by the Integrational Grant No 44 and The Ministry of education and science of Russia, project 14.A18.21.2014.
. - 6. - ISSN 1007-5704
РУБ Mathematics, Applied + Mathematics, Interdisciplinary Applications + Mechanics + Physics, Fluids & Plasmas + Physics, Mathematical
Кл.слова (ненормированные):
Lie symmetry analysis -- Group classification -- Equivalence transformations -- Thermodiffusion -- Binary mixture -- Transport coefficients
Аннотация: Group classification problem is solved for equations of motion of a binary mixture under the buoyancy force and thermodiffusion effect. These equations are parameterized by five arbitrary functions of two arguments. The admissible Lie symmetry algebras of generators are found depending on arbitrary elements. These results are useful for analytical and numerical modeling of the convection in binary mixtures. (C) 2012 Elsevier B. V. All rights reserved.
Доп.точки доступа:
Stepanova, I.V.; Степанова, Ирина Владимировна
Кл.слова (ненормированные):
Lie symmetry analysis -- Group classification -- Equivalence transformations -- Thermodiffusion -- Binary mixture -- Transport coefficients
Аннотация: Group classification problem is solved for equations of motion of a binary mixture under the buoyancy force and thermodiffusion effect. These equations are parameterized by five arbitrary functions of two arguments. The admissible Lie symmetry algebras of generators are found depending on arbitrary elements. These results are useful for analytical and numerical modeling of the convection in binary mixtures. (C) 2012 Elsevier B. V. All rights reserved.
Доп.точки доступа:
Stepanova, I.V.; Степанова, Ирина Владимировна
MHD modeling of the double-gradient (kink) magnetic instability
/ D.B. Korovinskiy [et al.] // J. Geophys. Res-Space Phys. - 2013. - Vol. 118, Is. 3. - P1146-1158, DOI 10.1002/jgra.50206. - Cited References: 39. - This work is supported by the Austrian Science Fund (FWF): I193-N16, by the Onderzoekfonds KU Leuven (Research Fund KU Leuven), by RFBR Grants 12-05-00918-a and 12-05-00152-a, and by SPSU Grants 11.38.47.2011 and 11.38.84.2012. The research has received funding also from the European Union Seventh Framework Programme [FP7/2007-2013] under grant agreement 269198-Geoplasmas (Marie Curie International Research Staff Exchange Scheme) and 218816 (SOTERIA project). The simulations were conducted on the resources of the Vlaams Supercomputer Centrum (VSC) at the Katholieke Universiteit Leuven. N.V.E., V.S.S. and D.B.K. thank also ISSI for hospitality and financial support. The authors thank reviewers for their comments, which gave us the substantial aid in preparing of this manuscript.
. - 13. - ISSN 2169-9380
РУБ Astronomy & Astrophysics
Аннотация: The paper presents the detailed numerical investigation of the "double-gradient mode," which is believed to be responsible for the magnetotail flapping oscillations-the fast vertical (normal to the layer) oscillations of the Earth's magnetotail plasma sheet with a quasiperiod similar to 100-200 s. The instability is studied using the magnetotail near-equilibrium configuration. For the first time, linear three-dimensional numerical analysis is complemented with full 3-D MHD simulations. It is known that the "double-gradient mode" has unstable solutions in the region of the tailward growth of the magnetic field component, normal to the current sheet. The unstable kink branch of the mode is the focus of our study. Linear MHD code results agree with the theory, and the growth rate is found to be close to the peak value, provided by the analytical estimates. Full 3-D simulations are initialized with the numerically relaxed magnetotail equilibrium, similar to the linear code initial condition. The calculations show that current layer with tailward gradient of the normal component of the magnetic field is unstable to wavelengths longer than the curvature radius of the field line. The segment of the current sheet with the earthward gradient of the normal component makes some stabilizing effect (the same effect is registered in the linearized MHD simulations) due to the minimum of the total pressure localized in the center of the sheet. The overall growth rate is close to the theoretical double-gradient estimate averaged over the computational domain.
Полный текст на сайте правообладателя
Доп.точки доступа:
Korovinskiy, D.B.; Divin, A.; Erkaev, N.V.; Еркаев, Николай Васильевич; Ivanova, V.V.; Ivanov, I.B.; Semenov, V.S.; Lapenta, G.; Markidis, S.; Biernat, H.K.; Zellinger, M.
Рубрики:
CURRENT SHEET OSCILLATIONS
CLUSTER OBSERVATIONS
NEUTRAL SHEET
PLASMA SHEET
MAGNETOTAIL
SIMULATIONS
CONFIGURATIONS
STABILITY
CURRENT SHEET OSCILLATIONS
CLUSTER OBSERVATIONS
NEUTRAL SHEET
PLASMA SHEET
MAGNETOTAIL
SIMULATIONS
CONFIGURATIONS
STABILITY
Аннотация: The paper presents the detailed numerical investigation of the "double-gradient mode," which is believed to be responsible for the magnetotail flapping oscillations-the fast vertical (normal to the layer) oscillations of the Earth's magnetotail plasma sheet with a quasiperiod similar to 100-200 s. The instability is studied using the magnetotail near-equilibrium configuration. For the first time, linear three-dimensional numerical analysis is complemented with full 3-D MHD simulations. It is known that the "double-gradient mode" has unstable solutions in the region of the tailward growth of the magnetic field component, normal to the current sheet. The unstable kink branch of the mode is the focus of our study. Linear MHD code results agree with the theory, and the growth rate is found to be close to the peak value, provided by the analytical estimates. Full 3-D simulations are initialized with the numerically relaxed magnetotail equilibrium, similar to the linear code initial condition. The calculations show that current layer with tailward gradient of the normal component of the magnetic field is unstable to wavelengths longer than the curvature radius of the field line. The segment of the current sheet with the earthward gradient of the normal component makes some stabilizing effect (the same effect is registered in the linearized MHD simulations) due to the minimum of the total pressure localized in the center of the sheet. The overall growth rate is close to the theoretical double-gradient estimate averaged over the computational domain.
Полный текст на сайте правообладателя
Доп.точки доступа:
Korovinskiy, D.B.; Divin, A.; Erkaev, N.V.; Еркаев, Николай Васильевич; Ivanova, V.V.; Ivanov, I.B.; Semenov, V.S.; Lapenta, G.; Markidis, S.; Biernat, H.K.; Zellinger, M.
Current sheet oscillations in the magnetic filament approach
/ N.V. Erkaev, V.S. Semenov, H.K. Biernat // Phys. Plasmas. - 2012. - Vol. 19, Is. 6. - Ст. 62905, DOI 10.1063/1.4725506. - Cited References: 22. - This work is supported by RFBR Grants Nos. 12-05-00152-a and 12-05-00918-a, and also by St. Petersburg University grant. V. S. S. and H. K. B. are supported from the FP7 Programme under Grant No. 269198-Geoplasmas (Marie Curie Exchange Scheme). Additional support is due to the Austrian "Fonds zur Forderung der wissenschaftlichen Forschung" under Project I 193-N16 and the "Verwaltungsstelle fur Auslandsbeziehungen" of the Austrian Academy of Sciences.
. - ISSN 1070-664X
РУБ Physics, Fluids & Plasmas
Аннотация: Magnetic filament approach is applied for modeling of nonlinear "kink"-like flapping oscillations of thin magnetic flux tubes in the Earth's magnetotail current sheet. A discrete approximation for the magnetic flux tube was derived on a basis of the Hamiltonian formulation of the problem. The obtained system of ordinary differential equations was integrated by method of Rosenbrock, which is suitable for stiff equations. The two-dimensional exact Kan's solution of the Vlasov equations was used to set the background equilibrium conditions for magnetic field and plasma. Boundary conditions for the magnetic filament were found to be dependent on the ratio of the ionospheric conductivity and the Alfven conductivity of the magnetic tube. It was shown that an enhancement of this ratio leads to the corresponding increase of the frequency of the flapping oscillations. For some special case of boundary conditions, when the magnetic perturbations vanish at the boundaries, the calculated frequency of the "kink"-like flapping oscillations is rather close to that predicted by the "double gradient" analytical model. For others cases, the obtained frequency of the flapping oscillations is somewhat larger than that from the "double gradient" theory. The frequency of the nonlinear flapping oscillations was found to be a decreasing function of the amplitude. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4725506]
Доп.точки доступа:
Erkaev, N.V.; Еркаев, Николай Васильевич; Semenov, V.S.; Biernat, H.K.
Аннотация: Magnetic filament approach is applied for modeling of nonlinear "kink"-like flapping oscillations of thin magnetic flux tubes in the Earth's magnetotail current sheet. A discrete approximation for the magnetic flux tube was derived on a basis of the Hamiltonian formulation of the problem. The obtained system of ordinary differential equations was integrated by method of Rosenbrock, which is suitable for stiff equations. The two-dimensional exact Kan's solution of the Vlasov equations was used to set the background equilibrium conditions for magnetic field and plasma. Boundary conditions for the magnetic filament were found to be dependent on the ratio of the ionospheric conductivity and the Alfven conductivity of the magnetic tube. It was shown that an enhancement of this ratio leads to the corresponding increase of the frequency of the flapping oscillations. For some special case of boundary conditions, when the magnetic perturbations vanish at the boundaries, the calculated frequency of the "kink"-like flapping oscillations is rather close to that predicted by the "double gradient" analytical model. For others cases, the obtained frequency of the flapping oscillations is somewhat larger than that from the "double gradient" theory. The frequency of the nonlinear flapping oscillations was found to be a decreasing function of the amplitude. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4725506]
Доп.точки доступа:
Erkaev, N.V.; Еркаев, Николай Васильевич; Semenov, V.S.; Biernat, H.K.
Accelerated magnetosheath flows caused by IMF draping: Dependence on latitude
/ N. V. Erkaev [et al.] // Geophys. Res. Lett. - 2012. - Vol. 39. - Ст. L01103, DOI 10.1029/2011GL050209. - Cited References: 16. - This work was done while NVE 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 CJF was supported by NASA grants NNX10AQ29G and NNX08AD11G.
. - ISSN 0094-8276
РУБ Geosciences, Multidisciplinary
Аннотация: In previous work we used a semi-analytical treatment to describe accelerated magnetosheath flows caused by the draping of interplanetary magnetic field (IMF) lines around the magnetosphere. Here, we use the same approach, i.e., modeling the magnetic field lines as elastic strings, to examine how the magnetic tension force, one of the two agents responsible for producing these flows, varies along field lines away from the equatorial plane. The bend in the field line caused by the draping mechanism propagates as two oppositely-directed waves to higher latitudes. For a due northward IMF - the case we consider here - these propagate symmetrically north/south of the equatorial plane. As a result, a two-peaked latitude velocity profile develops as we go further downtail and the velocity peaks migrate along the magnetic field line to higher latitudes. We examine this velocity-profile for two Alfven Mach numbers (M-A = 8 and 3), representative of conditions in the solar wind at 1 AU ("normal" solar wind and solar transients). Qualitatively, the picture is the same but quantitatively there are important differences: (i) the flows reach higher values for the lower M-A (maximum V/V-SW = 1.6) than for the higher M-A (V/V-SW = 1.3); (ii) asymptotic values are reached farther downstream of the dawn-dusk terminator for the lower M-A (similar to-50 R-E vs -15 R-E); (iii) For the lower M-A the highest speeds are reached away from the equatorial plane. We predict two channels of fast magnetosheath flow next to the magnetopause at off-equatorial latitudes that exceed the solar wind speed. Citation: Erkaev, N. V., C. J. Farrugia, A. V. Mezentsev, R. B. Torbert, and H. K. Biernat (2012), Accelerated magnetosheath flows caused by IMF draping: Dependence on latitude, Geophys. Res. Lett., 39, L01103, doi:10.1029/2011GL050209.
Полный текст
Доп.точки доступа:
Erkaev, N.V.; Еркаев, Николай Васильевич; Farrugia, C.J.; Mezentsev, A.V.; Torbert, R.B.; Biernat, H.K.
Аннотация: In previous work we used a semi-analytical treatment to describe accelerated magnetosheath flows caused by the draping of interplanetary magnetic field (IMF) lines around the magnetosphere. Here, we use the same approach, i.e., modeling the magnetic field lines as elastic strings, to examine how the magnetic tension force, one of the two agents responsible for producing these flows, varies along field lines away from the equatorial plane. The bend in the field line caused by the draping mechanism propagates as two oppositely-directed waves to higher latitudes. For a due northward IMF - the case we consider here - these propagate symmetrically north/south of the equatorial plane. As a result, a two-peaked latitude velocity profile develops as we go further downtail and the velocity peaks migrate along the magnetic field line to higher latitudes. We examine this velocity-profile for two Alfven Mach numbers (M-A = 8 and 3), representative of conditions in the solar wind at 1 AU ("normal" solar wind and solar transients). Qualitatively, the picture is the same but quantitatively there are important differences: (i) the flows reach higher values for the lower M-A (maximum V/V-SW = 1.6) than for the higher M-A (V/V-SW = 1.3); (ii) asymptotic values are reached farther downstream of the dawn-dusk terminator for the lower M-A (similar to-50 R-E vs -15 R-E); (iii) For the lower M-A the highest speeds are reached away from the equatorial plane. We predict two channels of fast magnetosheath flow next to the magnetopause at off-equatorial latitudes that exceed the solar wind speed. Citation: Erkaev, N. V., C. J. Farrugia, A. V. Mezentsev, R. B. Torbert, and H. K. Biernat (2012), Accelerated magnetosheath flows caused by IMF draping: Dependence on latitude, Geophys. Res. Lett., 39, L01103, doi:10.1029/2011GL050209.
Полный текст
Доп.точки доступа:
Erkaev, N.V.; Еркаев, Николай Васильевич; Farrugia, C.J.; Mezentsev, A.V.; Torbert, R.B.; Biernat, H.K.
Parallel Program Systems for Modeling Elastic-Plastic Waves in Structurally Inhomogeneous Materials
/ V. M. Sadovskii, O. V. Sadovskaya ; ed. by T.E.Simos [et al.] // NUMERICAL ANALYSIS AND APPLIED MATHEMATICS (ICNAAM 2012), VOLS A AND B. Ser. AIP Conference Proceedings : AMER INST PHYSICS, 2012. - Vol. 1479: International Conference of Numerical Analysis and Applied Mathematics (ICNAAM) (SEP 19-25, 2012, Kos, GREECE). - pp. 1611-1614, DOI 10.1063/1.4756474. - Cited References: 4
. - ISBN 0094-243X. - ISBN 978-0-7354-1091-6
РУБ Mathematics, Applied + Physics, Applied
Кл.слова (ненормированные):
Dynamics -- Rheology -- Microstructure -- Elasticity -- Plasticity -- Granular material -- Cosserat continuum -- Shock wave -- Variational inequality -- Finite-difference scheme -- Parallel computational algorithm
Аннотация: Parallel program systems for numerical solution of 2D and 3D problems of the dynamics of deformable media with constitutive relationships of rather general form on the basis of universal mathematical model describing small strains of elastic, elastic-plastic and granular materials are worked out. Some computations of dynamic problems with and without taking into account the moment properties of a material were performed on supercomputers with cluster architecture.
РИНЦ
Доп.точки доступа:
Sadovskii, V.M.; Садовский, Владимир Михайлович; Sadovskaya, O.V.; Садовская, Оксана Викторовна; Simos, T.E. \ed.\; Psihoyios, G. \ed.\; Tsitouras, C. \ed.\
Кл.слова (ненормированные):
Dynamics -- Rheology -- Microstructure -- Elasticity -- Plasticity -- Granular material -- Cosserat continuum -- Shock wave -- Variational inequality -- Finite-difference scheme -- Parallel computational algorithm
Аннотация: Parallel program systems for numerical solution of 2D and 3D problems of the dynamics of deformable media with constitutive relationships of rather general form on the basis of universal mathematical model describing small strains of elastic, elastic-plastic and granular materials are worked out. Some computations of dynamic problems with and without taking into account the moment properties of a material were performed on supercomputers with cluster architecture.
РИНЦ
Доп.точки доступа:
Sadovskii, V.M.; Садовский, Владимир Михайлович; Sadovskaya, O.V.; Садовская, Оксана Викторовна; Simos, T.E. \ed.\; Psihoyios, G. \ed.\; Tsitouras, C. \ed.\