TY  - JOUR
A1  - Weßling, Matthias
T1  - Unternehmenskultur
JF  - Ergebnisse empirischer betriebswirtschaftlicher Forschung : zu einer Realtheorie der Unternehmung ; Festschrift für Eberhard Witte / Jürgen Hauschildt ... (Hrsg.)
Y1  - 1993
SN  - 3-7910-0678-9
SP  - 115
EP  - 134
PB  - Schäffer-Poeschel
CY  - Stuttgart
ER  - 
TY  - JOUR
A1  - Valero, Daniel
A1  - Bung, Daniel B.
A1  - Erpicum, Sebastien
A1  - Peltier, Yann
A1  - Dewals, Benjamin
T1  - Unsteady shallow meandering flows in rectangular reservoirs: a modal analysis of URANS modelling
JF  - Journal of Hydro-environment Research
N2  - Shallow flows are common in natural and human-made environments. Even for simple rectangular shallow reservoirs, recent laboratory experiments show that the developing flow fields are particularly complex, involving large-scale turbulent structures. For specific combinations of reservoir size and hydraulic conditions, a meandering jet can be observed. While some aspects of this pseudo-2D flow pattern can be reproduced using a 2D numerical model, new 3D simulations, based on the unsteady Reynolds-Averaged Navier-Stokes equations, show consistent advantages as presented herein. A Proper Orthogonal Decomposition was used to characterize the four most energetic modes of the meandering jet at the free surface level, allowing comparison against experimental data and 2D (depth-averaged) numerical results. Three different isotropic eddy viscosity models (RNG k-ε, k-ε, k-ω) were tested. The 3D models accurately predicted the frequency of the modes, whereas the amplitudes of the modes and associated energy were damped for the friction-dominant cases and augmented for non-frictional ones. The performance of the three turbulence models remained essentially similar, with slightly better predictions by RNG k-ε model in the case with the highest Reynolds number. Finally, the Q-criterion was used to identify vortices and study their dynamics, assisting on the identification of the differences between: i) the three-dimensional phenomenon (here reproduced), ii) its two-dimensional footprint in the free surface (experimental observations) and iii) the depth-averaged case (represented by 2D models).
KW  - coherent structures
KW  - hydraulic modelling
KW  - model performance
KW  - Proper Orthogonal Decomposition
KW  - Q-criterion
Y1  - 2022
U6  - http://dx.doi.org/10.1016/j.jher.2022.03.002
SN  - 1570-6443
IS  - In Press
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Ferrein, Alexander
A1  - Jacobs, Stefan
A1  - Lakemeyer, Gerhard
T1  - Unreal Golog Bots / Jacobs, Stefan ; Ferrein, Alexander ; Lakemeyer, Gerhard
JF  - IJCAI-05 Workshop on Reasoning, Representation, and Learning in Computer Games
Y1  - 2005
SP  - 31
EP  - 36
ER  - 
TY  - JOUR
A1  - Bialonski, Stephan
A1  - Wendler, Martin
A1  - Lehnertz, Klaus
T1  - Unraveling spurious properties of interaction networks with tailored random networks
JF  - Plos one
N2  - We investigate interaction networks that we derive from multivariate time series with methods frequently employed in diverse scientific fields such as biology, quantitative finance, physics, earth and climate sciences, and the neurosciences. Mimicking experimental situations, we generate time series with finite length and varying frequency content but from independent stochastic processes. Using the correlation coefficient and the maximum cross-correlation, we estimate interdependencies between these time series. With clustering coefficient and average shortest path length, we observe unweighted interaction networks, derived via thresholding the values of interdependence, to possess non-trivial topologies as compared to Erdös-Rényi networks, which would indicate small-world characteristics. These topologies reflect the mostly unavoidable finiteness of the data, which limits the reliability of typically used estimators of signal interdependence. We propose random networks that are tailored to the way interaction networks are derived from empirical data. Through an exemplary investigation of multichannel electroencephalographic recordings of epileptic seizures – known for their complex spatial and temporal dynamics – we show that such random networks help to distinguish network properties of interdependence structures related to seizure dynamics from those spuriously induced by the applied methods of analysis.
Y1  - 2011
U6  - http://dx.doi.org/10.1371/journal.pone.0022826
VL  - 6
IS  - 8
PB  - Plos
CY  - San Francisco
ER  - 
TY  - JOUR
A1  - Meliß, Michael
A1  - Bünde, R.
T1  - Unkonventionelle Energiequellen - Entwicklungsstudien (4)
JF  - Brennstoff, Wärme, Kraft : BWK
Y1  - 1978
SN  - 0006-9612 (Print) ; 1436-4883 (E-Journal)
VL  - 30
IS  - 3
SP  - 120
EP  - 126
PB  - Springer-VDI-Verlag
CY  - Düsseldorf
ER  - 
TY  - JOUR
A1  - Starke, Günther
A1  - Drews, P.
T1  - Universelles Roboterprogrammiersystem zur Fertigung von Großfahrzeugen
JF  - Schweißen und Schneiden. 47 (1995), H. 9
Y1  - 1995
SN  - 0036-7184
SP  - 707
EP  - 713
ER  - 
TY  - JOUR
A1  - Engels, Elmar
A1  - Wiendahl, H.-P.
A1  - Doege, E.
T1  - Universelle hydraulische Try-Out Presse / Teilprojekt A6 / Wiendahl, H.-P. ; Doege, E. ; Engels, E.
JF  - Tagungsband : 12. Oktober 1999, Leibnizhaus Hannover / Sonderforschungsbereich 384 Verfügbarkeitssicherung Reaktionsschneller Produktionssysteme, Universität Hannover. Hrsg.: H.-P. Wiendahl ; M. Röhrig
Y1  - 1999
SN  - 3-00-005495-2
N1  - Industriekolloquium Verfügbarkeit <1999, Hannover> ; Sonderforschungsbereich Verfügbarkeitssicherung Reaktionsschneller Produktionssysteme <Hannover>
CY  - Hannover
ER  - 
TY  - JOUR
A1  - Stulpe, Werner
T1  - Unitary Operator
JF  - Compendium of Quantum Physics : concepts, experiments, history and philosophy / Daniel Greenberger ... ed.
Y1  - 2009
SN  - 978-3-540-70622-9
SP  - 807
EP  - 809
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Reißel, Martin
A1  - Lustfeld, H.
A1  - Hirschfeld, J.
A1  - Steffen, B.
T1  - Uniqueness of magnetotomography for fuel cells and fuel cell stacks / Lustfeld, H. ; Hirschfeld, J. ; Reißel, M ; Steffen, B.
JF  - Journal of Physics A: Mathematical and Theoretical. 42 (2009), H.  495205
Y1  - 2009
SN  - 0022-3689
SP  - 9 S.
ER  - 
TY  - JOUR
A1  - Schäfer, Horst
A1  - Worschech, L.
A1  - Ossau, W.
A1  - Landwehr, G.
T1  - Uniaxiale und planare Verspannung von Störstellenkomplexen in ZnSe/GaAs Schichten
Y1  - 1997
N1  - Als Poster vorgelegt auf der Frühjahrstagung der DPG in Münster, 17.-21. März 1997, Verhandl. DPG (VI) 32, HL 11.51 / Physikalisches Institut der Universität Würzburg.
ER  -