TY - JOUR A1 - Weigand, Christoph T1 - Defining Precisions for Reliable Measurement and Estimation Procedures JF - Economic Quality Control. 24 (2009), H. 1 Y1 - 2009 SN - 0940-5151 SP - 5 EP - 33 PB - De Gruyter CY - Berlin ER - TY - JOUR A1 - Weigand, Christoph T1 - Economically Optimal Inspection Policy with Geometrical Adaption JF - Journal of Applied Statistics. 30 (2003), H. 5 Y1 - 2003 SN - 0266-4763 N1 - weitere ISSN 1360-0532 (E) SP - 555 EP - 569 ER - TY - JOUR A1 - Weigand, Christoph T1 - Economically Optimal Inspection Policy with Arithmetical Adaption JF - Applied stochastic models and data analysis / [10th International Symposium on Applied Stochastic Models and Analysis, June 12-15 2001, Université Technologique de Compiègne] ; editors Gérard Govaert, Jacques Janssen, Nikolaos Limnios. Y1 - 2001 N1 - ASDMA 2001 SP - 1010 EP - 1015 PB - Université Technologique de Compiègne CY - Compiègne ER - TY - JOUR A1 - Valero, Daniel A1 - Bung, Daniel Bernhard 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 - https://doi.org/10.1016/j.jher.2022.03.002 SN - 1570-6443 IS - In Press PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Dachwald, Bernd T1 - Optimization of very-low-thrust trajectories using evolutionary neurocontrol JF - Acta Astronautica N2 - Searching optimal interplanetary trajectories for low-thrust spacecraft is usually a difficult and time-consuming task that involves much experience and expert knowledge in astrodynamics and optimal control theory. This is because the convergence behavior of traditional local optimizers, which are based on numerical optimal control methods, depends on an adequate initial guess, which is often hard to find, especially for very-low-thrust trajectories that necessitate many revolutions around the sun. The obtained solutions are typically close to the initial guess that is rarely close to the (unknown) global optimum. Within this paper, trajectory optimization problems are attacked from the perspective of artificial intelligence and machine learning. Inspired by natural archetypes, a smart global method for low-thrust trajectory optimization is proposed that fuses artificial neural networks and evolutionary algorithms into so-called evolutionary neurocontrollers. This novel method runs without an initial guess and does not require the attendance of an expert in astrodynamics and optimal control theory. This paper details how evolutionary neurocontrol works and how it could be implemented. The performance of the method is assessed for three different interplanetary missions with a thrust to mass ratio <0.15mN/kg (solar sail and nuclear electric). Y1 - 2005 SN - 1879-2030 VL - 57 IS - 2-8 SP - 175 EP - 185 PB - Elsevier CY - Amsterdam [u.a.] ER - TY - JOUR A1 - Krämer, Marco A1 - Bongaerts, Johannes A1 - Bovenberg, Roel A1 - Kremer, Susanne A1 - Müller, Ulrike A1 - Orf, Sonja A1 - Wubbolts, Marcel A1 - Raeven, Leon T1 - Metabolic engineering for microbial production of shikimic acid JF - Metabolic engineering Y1 - 2003 SN - 1096-7184 (E-Journal); 1096-7176 (Print) VL - Vol. 5 IS - Iss. 4 SP - 277 EP - 283 ER - TY - CHAP A1 - Niemueller, Tim A1 - Lakemeyer, Gerhard A1 - Ferrein, Alexander ED - Finzi, Alberto T1 - The RoboCup Logistics League as a Benchmark for Planning in Robotics T2 - Proceedings of the 3rd Workshop on Planning and Robotics (PlanRob-15); Jerusalem, Israel 7-8/6/2015 Y1 - 2015 SP - 63 EP - 68 ER - TY - JOUR A1 - Staat, Manfred A1 - Baroud, G. A1 - Topcu, M. A1 - Sponagel, Stefan T1 - Soft Materials in Technology and Biology – Characteristics, Properties, and Parameter Identification JF - Bioengineering in Cell and Tissue Research / Artmann, Gerhard M. ; Chien, Shu (Eds.) Y1 - 2008 SN - 978-3-540-75408-4 SP - 253 EP - 315 PB - Springer CY - Berlin ER - TY - JOUR A1 - Akimbekov, Nuraly S. A1 - Digel, Ilya A1 - Tastambek, K. T. A1 - Zhubanova, A. A. T1 - Biocompatibility of carbonized rice husk with a rat heart cells line H9c2 JF - Experimental Biology Y1 - 2013 SN - 1563-0218 N1 - Original in russischer Sprache VL - 59 IS - 3/1 SP - 23 EP - 25 ER - TY - CHAP A1 - Niederwestberg, Stefan A1 - Schneider, Falko A1 - Teixeira Boura, Cristiano José A1 - Herrmann, Ulf T1 - Introduction to a direct irradiated transparent tube particle receiver T2 - SOLARPACES 2020 N2 - New materials often lead to innovations and advantages in technical applications. This also applies to the particle receiver proposed in this work that deploys high-temperature and scratch resistant transparent ceramics. With this receiver design, particles are heated through direct-contact concentrated solar irradiance while flowing downwards through tubular transparent ceramics from top to bottom. In this paper, the developed particle receiver as well as advantages and disadvantages are described. Investigations on the particle heat-up characteristics from solar irradiance were carried out with DEM simulations which indicate that particle temperatures can reach up to 1200 K. Additionally, a simulation model was set up for investigating the dynamic behavior. A test receiver at laboratory scale has been designed and is currently being built. In upcoming tests, the receiver test rig will be used to validate the simulation results. The design and the measurement equipment is described in this work. KW - Solar irradiance KW - Ceramics Y1 - 2022 SN - 978-0-7354-4195-8 U6 - https://doi.org/10.1063/5.0086735 SN - 1551-7616 (online) SN - 0094-243X (print) N1 - SOLARPACES 2020: 26th International Conference on Concentrating Solar Power and Chemical Energy Systems, 28 September–2 October 2020, Freiburg, Germany IS - 2445 / 1 PB - AIP conference proceedings / American Institute of Physics CY - Melville, NY ER -