TY - JOUR A1 - Wittmann, Klaus A1 - Kehr, J. A1 - Willnecker, R. T1 - Decentralized Payload Operations Concept for Columbus Y1 - 2000 N1 - 51st IAF Congress, Rio de Janeiro, Brazil, Oct. 2000 ER - TY - JOUR A1 - Wittmann, Klaus A1 - Gillessen, F. A1 - Otto, G. A1 - Röstel, R. T1 - Undercooling and solidification of metallic melts suspended in a non-nucleating matrix: Experiment NUCAL of the German Spacelab Mission D-2 JF - Acta Astronautica. 38 (1996), H. 1 Y1 - 1996 SN - 0094-5765 SP - 63 EP - 68 ER - TY - JOUR A1 - Wittmann, Klaus A1 - Fortezza, R. T1 - Telescience opportunities in the precursor flights JF - Space Technology - Industrial and Commercial Applications. 13 (1992), H. 2 Y1 - 1992 SN - 0892-9270 SP - 221 EP - 226 ER - TY - JOUR A1 - Wittmann, Klaus A1 - Feuerbacher, B. A1 - Ulamec, S. A1 - Rosenbauer, H. (u.a.) T1 - Rosetta Lander - In Situ Characterisation of a Comet Nucleus JF - Acta Astronautica. 45 (1999), H. 4-9 Y1 - 1999 SN - 0094-5765 SP - 389 EP - 395 ER - TY - JOUR A1 - Wittmann, Klaus A1 - Bibring, J.-P. A1 - Rosenbauer, H. A1 - Boehnhardt, H. T1 - The Rosetta Lander (“Philae”) Investigations / Bibring, J.-P. ; Rosenbauer, H. ; Boehnhardt, H. ; [...] Wittmann, K. JF - Space Science Reviews. 128 (2007), H. 1-4 Y1 - 2007 SN - 0038-6308 SP - 205 EP - 220 ER - TY - JOUR A1 - Wittmann, Klaus A1 - Bewersdorff, A. A1 - Görler, G.P. A1 - Otto, G. T1 - Solidification of silver-germanium alloys in an amorphous matrix aboard the space station Mir JF - Acta Astronautica. 29 (1993), H. 7 Y1 - 1993 SN - 0094-5765 SP - 547 EP - 552 ER - TY - JOUR A1 - Wittmann, Klaus T1 - The microgravity User Support Centre JF - Space Technology - Industrial and Commercial Applications. 13 (1993), H. 2 Y1 - 1993 SN - 0892-9270 SP - 121 EP - 124 ER - TY - JOUR A1 - Wittmann, Klaus T1 - Overview of Space Operations at DLR Y1 - 2000 N1 - SpaceOps2000 Conference, Toulouse, Frankreich,19-23 June 2000 ER - TY - CHAP A1 - Wittig, M. A1 - Rütters, René A1 - Bragard, Michael ED - Reiff-Stephan, Jörg ED - Jäkel, Jens ED - Schwarz, André T1 - Application of RL in control systems using the example of a rotatory inverted pendulum T2 - Tagungsband AALE 2024 : Fit für die Zukunft: praktische Lösungen für die industrielle Automation N2 - In this paper, the use of reinforcement learning (RL) in control systems is investigated using a rotatory inverted pendulum as an example. The control behavior of an RL controller is compared to that of traditional LQR and MPC controllers. This is done by evaluating their behavior under optimal conditions, their disturbance behavior, their robustness and their development process. All the investigated controllers are developed using MATLAB and the Simulink simulation environment and later deployed to a real pendulum model powered by a Raspberry Pi. The RL algorithm used is Proximal Policy Optimization (PPO). The LQR controller exhibits an easy development process, an average to good control behavior and average to good robustness. A linear MPC controller could show excellent results under optimal operating conditions. However, when subjected to disturbances or deviations from the equilibrium point, it showed poor performance and sometimes instable behavior. Employing a nonlinear MPC Controller in real time was not possible due to the high computational effort involved. The RL controller exhibits by far the most versatile and robust control behavior. When operated in the simulation environment, it achieved a high control accuracy. When employed in the real system, however, it only shows average accuracy and a significantly greater performance loss compared to the simulation than the traditional controllers. With MATLAB, it is not yet possible to directly post-train the RL controller on the Raspberry Pi, which is an obstacle to the practical application of RL in a prototyping or teaching setting. Nevertheless, RL in general proves to be a flexible and powerful control method, which is well suited for complex or nonlinear systems where traditional controllers struggle. KW - Rotatory Inverted Pendulum KW - MPC KW - LQR KW - PPO KW - Reinforcement Learning Y1 - 2024 SN - 978-3-910103-02-3 U6 - https://doi.org/10.33968/2024.53 N1 - 20. AALE-Konferenz. Bielefeld, 06.03.-08.03.2024. (Tagungsband unter https://doi.org/10.33968/2024.29) SP - 241 EP - 248 PB - le-tex publishing services GmbH CY - Leipzig ER - TY - BOOK A1 - Witte, Bertold A1 - Sparla, Peter T1 - Vermessungskunde und Grundlagen der Statistik für das Bauwesen Y1 - 2011 SN - 978-3-87907-497-6 PB - Wichmann CY - Heidelberg ET - 7., überarb. erw. Aufl. ER - TY - JOUR A1 - Witt, Klaus A1 - Bogner, D. T1 - Druckmessung mit zukunftsorientierten Perspektiven JF - Sensor Report. 5 (1990), H. 1 Y1 - 1990 SN - 0179-9592 SP - 8 EP - 14 ER - TY - JOUR A1 - Wissenbach, U. A1 - Six, S. A1 - Bongaerts, Johannes A1 - Ternes, D. A1 - Steinwachs, S. A1 - Unden, G. T1 - A third periplasmic transport system for l-arginine in Escherichia coli: molecular characterization of the artPIQMJ genes, arginine binding and transport JF - Molecular microbiology Y1 - 1995 SN - 1365-2958 (E-Journal); 0950-382x (Print) VL - Vol. 17 IS - Iss. 4 SP - 675 EP - 686 ER - TY - JOUR A1 - Wissen, M. A1 - Bogdanski, N. A1 - Scheer, H.-C. A1 - Bitz, Andreas A1 - Ahrens, G. A1 - Gruetzner, G. T1 - Implication of the light polarisation for UV curing of pre-patterned resists JF - Microelectronic Engineering Y1 - 2005 U6 - https://doi.org/10.1016/j.mee.2004.12.099 SN - 0167-9317 VL - 78-79 SP - 659 EP - 664 ER - TY - BOOK A1 - Winkler, Norbert T1 - Zahlentafeln für den Baubetrieb / Hoffmann, Manfred [Hrsg.]. 6., vollst. aktualisierte Aufl. ... Norbert Winkler [Bearb.] Y1 - 2002 SN - 3-519-55220-5 PB - Teubner CY - Stuttgart [u.a.] ER - TY - JOUR A1 - Winkler, Norbert T1 - Vermessung zur Bauzeit der Zitadelle und heute : Bastion Wilhelmus / von Norbert Winkler JF - 4 Bastionen, 4 Aspekte : aktuelle Arbeiten zur Zitadelle Jülich ; Katalog zur Ausstellung im Hexenturm 10.11.95 - 14.02.96 / [Veranst.: Stadtgeschichtliches Museum Jülich]. Mit Beitr. von Guido von Büren ... [Hrsg.: Marcell Perse] Y1 - 1995 N1 - Führer des Stadtgeschichtlichen Museums Jülich ; 7 SP - 77 EP - 115 CY - Jülich ER - TY - JOUR A1 - Winkler, Norbert T1 - Vermessung JF - Zahlentafeln für den Baubetrieb / Hoffmann, Manfred ; Kuhlmann, Willy [Hrsg.]. 7., vollst. überarb. Aufl. Y1 - 2006 SN - 3-519-65220-X N1 - Kapitel 3 SP - 147 EP - 160 PB - Teubner CY - Wiesbaden ER - TY - JOUR A1 - Winkler, Norbert T1 - Vermessung JF - Beispiele für die Baubetriebspraxis / Hoffmann, Manfred ; Kuhlmann, Willy [Hrsg.]. Y1 - 2006 SN - 978-3-8351-0002-2 N1 - Kapitel 2 SP - 9 EP - 34 PB - Teubner CY - Wiesbaden ER - TY - CHAP A1 - Winkler, Norbert T1 - Vermessung T2 - Zahlentafeln für den Baubetrieb Y1 - 2016 SN - 978-3-658-02838-1 (Online) SN - 978-3-658-02837-4 (Print) U6 - https://doi.org/10.1007/978-3-658-02838-1_3 SP - 159 EP - 177 PB - Springer Vieweg CY - Wiesbaden ET - 9., überarb. und aktual. Aufl. ER - TY - JOUR A1 - Wingens, Niklas A1 - May, Jörg A1 - Pfaff, Raphael T1 - Betrieblich-technische Innovationsansätze zur Bremsprobe nach einer Prozessänderung JF - ETR - Eisenbahntechnische Rundschau Y1 - 2019 SN - 0013-2845 IS - 5 PB - DVV Media Group CY - Hamburg ER - TY - JOUR A1 - Windmüller, Anna A1 - Schaps, Kristian A1 - Zantis, Frederik A1 - Domgans, Anna A1 - Taklu, Bereket Woldegbreal A1 - Yang, Tingting A1 - Tsai, Chih-Long A1 - Schierholz, Roland A1 - Yu, Shicheng A1 - Kungl, Hans A1 - Tempel, Hermann A1 - Dunin-Borkowski, Rafal E. A1 - Hüning, Felix A1 - Hwang, Bing Joe A1 - Eichel, Rüdiger-A. T1 - Electrochemical activation of LiGaO2: implications for ga-doped garnet solid electrolytes in li-metal batteries JF - ACS Applied Materials & Interfaces N2 - Ga-doped Li7La3Zr2O12 garnet solid electrolytes exhibit the highest Li-ion conductivities among the oxide-type garnet-structured solid electrolytes, but instabilities toward Li metal hamper their practical application. The instabilities have been assigned to direct chemical reactions between LiGaO2 coexisting phases and Li metal by several groups previously. Yet, the understanding of the role of LiGaO2 in the electrochemical cell and its electrochemical properties is still lacking. Here, we are investigating the electrochemical properties of LiGaO2 through electrochemical tests in galvanostatic cells versus Li metal and complementary ex situ studies via confocal Raman microscopy, quantitative phase analysis based on powder X-ray diffraction, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and electron energy loss spectroscopy. The results demonstrate considerable and surprising electrochemical activity, with high reversibility. A three-stage reaction mechanism is derived, including reversible electrochemical reactions that lead to the formation of highly electronically conducting products. The results have considerable implications for the use of Ga-doped Li7La3Zr2O12 electrolytes in all-solid-state Li-metal battery applications and raise the need for advanced materials engineering to realize Ga-doped Li7La3Zr2O12for practical use. KW - LiGaO2 KW - garnet solid electrolyte KW - ga-doping KW - Li7La3Zr2O12 KW - solid-state battery Y1 - 2024 U6 - https://doi.org/10.1021/acsami.4c03729 SN - 39181–3919 VL - 16 IS - 30 PB - ACS Publications CY - Washington, DC ER -