TY  - JOUR
A1  - Schaub, Torsten
A1  - Wang, Kewen
T1  - A comparative study of logic programs with preference
Y1  - 2001
SN  - 1-558-60777-3
SN  - 1045-0823
ER  - 
TY  - JOUR
A1  - Delgrande, James Patrick
A1  - Schaub, Torsten
A1  - Tompits, Hans
T1  - A generic compiler for ordered logic programs
Y1  - 2001
SN  - 3-540-42593-4
ER  - 
TY  - BOOK
ED  - Brewka, Gerhard
ED  - Witteveen, Cees
ED  - Schaub, Torsten
T1  - Proceedings of the Fifth Dutch German Workshop on Nonmonotonic Reasoning Techniques and their Applications, DGNMR'2001, Potsdam, 4. - 6. April 2001
Y1  - 2001
CY  - Potsdam
ER  - 
TY  - JOUR
A1  - Hamann, Wolf-Rainer
A1  - Brown, John C.
A1  - Feldmeier, Achim
A1  - Oskinova, Lidia M.
T1  - On the wavelength drift of spectral features from structured hot star winds
N2  - Spectral lines formed in stellar winds from OB stars are observed to exhibit profile variations. Discrete Absorption Components (DACs) show a remarkably slow wavelength drift with time. In a straightforward interpretation, this is in sharp contradiction to the steep velocity law predicted by the radiation-driven wind theory, and by semi- empirical profile fitting. In the present paper we re-discuss the interpretation of the drift rate. We show that the Co- rotating Interaction Region (CIR) model for the formation of DACs does not explain their slow drift rate as a consequence of rotation. On the contrary, the apparent acceleration of a spectral CIR feature is even higher than for the corresponding kinematical model without rotation. However, the observations can be understood by distinguishing between the velocity field of the matter flow, and the velocity law for the motion of the patterns in which the DAC features are formed. If the latter propagate upstream against the matter flow, the resulting wavelength drift mimics a much slower acceleration although the matter is moving fast. Additional to the DACs, a second type of recurrent structures is present in observed OB star spectra, the so-called modulations. In contrast to the DACs, these structures show a steep acceleration compatible with the theoretically predicted velocity law. We see only two possible consistent scenarios. Either, the wind is accelerated fast, and the modulations are formed in advected structures, while the DACs come from structures which are propagating upstream. Or, alternatively, steep and shallow velocity laws may co-exist at the same time in different spatial regions or directions of the wind.
Y1  - 2001
ER  - 
TY  - JOUR
A1  - Roessner, Ute
A1  - Luedemann, A.
A1  - Brust, D.
A1  - Fiehn, Oliver
A1  - Linke, Thomas
A1  - Willmitzer, Lothar
A1  - Fernie, Alisdair
T1  - Metabolic profiling allows comprehensive phenotyping of genetically or environmentally modified plant systems
Y1  - 2001
SN  - 1040-4651
ER  -