ALBERT — All Library Books, journals and Electronic Records Telegrafenberg

Treffer pro Seite

Treffer 1 - 3 | 3 Treffer

Sortierung

Digitale Medien

Discrete stability of the Differential System Method evaluated with geostatistical techniques (1998)

Giudici, M. ; Delay, F. ; de Marsily, G. ; [weitere]

Springer

Stochastic environmental research and risk assessment 12 (1998), S. 191-204

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1436-3259

Schlagwort(e): Keywords: groundwater flow ; inverse problems ; stability ; geostatistical interpolation ; kriging.

Quelle: Springer Online Journal Archives 1860-2000

Thema: Architektur, Bauingenieurwesen, Vermessung , Energietechnik , Geographie , Geologie und Paläontologie

Notizen: Abstract The Differential System Method (DSM) permits identification of the physical parameters of finite-difference groundwater flow models in a confined aquifer when piezometric head and source terms are known at each point of the finite-difference lattice for at least two independent flow situations for which the hydraulic gradients are not parallel. Since piezometric head data are usually few and sparse, interpolation of the measured data onto a regular grid can be performed with geostatistical techniques. We apply kriging to the sparse data of a synthetic aquifer to evaluate the stability of the DSM with respect to uncorrelated measurement errors and interpolation errors. The numerical results show that the DSM is stable.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/s004770050017

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

Digitale Medien

Bifurcations in Spherical MHD Models (1998)

Fuchs, H. ; Rädler, K.-H.

Springer

Studia geophysica et geodaetica 42 (1998), S. 320-327

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1573-1626

Schlagwort(e): MHD ; stability ; bifurcations

Quelle: Springer Online Journal Archives 1860-2000

Thema: Architektur, Bauingenieurwesen, Vermessung , Geologie und Paläontologie , Physik

Notizen: Abstract A series of numerical studies on the behaviour of magnetic fields and motions in a spherical body of an electrically conducting incompressible fluid have been carried out. The magnetic field was assumed to be maintained by a given electromotive force inside the body and to continue as a potential field in outer space. In view of the motion an external forcing was taken into account, and boundary conditions were considered which correspond to a stress-free surface. The stability of several steady states has been studied as well as the evolutions starting from unstable states. In this paper a configuration with a poloidal magnetic field and a differential rotation, both symmetric about the same axis, is considered. This configuration is stable only for sufficiently small Hartmann numbers but evolves, if disturbed, in the case of larger Hartmann numbers toward a non-axisymmetric state. In this case the well-known symmetrization effect of differential rotation in magnetic fields is destroyed.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1023/A:1023356720631

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

Digitale Medien

Orbital Migration Of Giant Planets: Using Numerical Integration To Investigate Consequences For Other Bodies (1999)

Sleep, Peter N.

Springer

Earth, moon and planets 87 (1999), S. 103-115

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1573-0794

Schlagwort(e): Accretion ; exoplanetary system ; extrasolar planets ; numerical integration ; orbital migration ; stability

Quelle: Springer Online Journal Archives 1860-2000

Thema: Geologie und Paläontologie , Physik

Notizen: Abstract A number of extrasolar planets have been detected in close orbits around nearby stars. It is probable that these planets did not form in these orbits but migrated from their formation locations beyond the ice line. Orbital migration mechanisms involving angular momentum transfer through tidal interactions between the planets and circumstellar gas-dust disks or by gravitational interaction with a residual planetesimal disk together with several means of halting inward migration have been identified. These offer plausible schemes to explain the orbits of observed extrasolar giant planets and giant planets within the Solar System. Recent advances in numerical integration methods and in the power of computer workstations have allowed these techniques to be applied to modelling directly the mechanisms and consequences of orbital migration in the Solar System. There is now potential for these techniques also to be applied to modelling the consequences of the orbital migration of planets in the observed exoplanetary systems. In particular the detailed investigation of the stability of terrestrial planets in the habitable zone of these systems and the formation of terrestrial planets after the dissipation of the gas disk is now possible. The stability of terrestrial planets in the habitable zone of selected exoplanetary systems has been established and the possibility of the accretion of terrestrial planets in these systems is being investigated by the author in collaboration with Barrie W. Jones (Open University), and with John Chambers (NASA-Ames) and Mark Bailey of Armagh Observatory, using numerical integration. The direct simulation of orbital migration by planetesimal scattering must probably await faster hardware and/or more efficient algorithms.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1023/A:1017996927696

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

Treffer 1 - 3 | 3 Treffer