TY - CHAP A1 - Dachwald, Bernd T1 - Low-Thrust Mission Analysis and Global Trajectory Optimization Using Evolutionary Neurocontrol: New Results T2 - European Workshop on Space Mission Analysis ESA/ESOC, Darmstadt, Germany 10 { 12 Dec 2007 N2 - Interplanetary trajectories for low-thrust spacecraft are often characterized by multiple revolutions around the sun. Unfortunately, the convergence of traditional trajectory optimizers that are based on numerical optimal control methods depends strongly on an adequate initial guess for the control function (if a direct method is used) or for the starting values of the adjoint vector (if an indirect method is used). Especially when many revolutions around the sun are re- quired, trajectory optimization becomes a very difficult and time-consuming task that involves a lot of experience and expert knowledge in astrodynamics and optimal control theory, because an adequate initial guess is extremely hard to find. Evolutionary neurocontrol (ENC) was proposed as a smart method for low-thrust trajectory optimization that fuses artificial neural networks and evolutionary algorithms to so-called evolutionary neurocontrollers (ENCs) [1]. Inspired by natural archetypes, ENC attacks the trajectoryoptimization problem from the perspective of artificial intelligence and machine learning, a perspective that is quite different from that of optimal control theory. Within the context of ENC, a trajectory is regarded as the result of a spacecraft steering strategy that maps permanently the actual spacecraft state and the actual target state onto the actual spacecraft control vector. This way, the problem of searching the optimal spacecraft trajectory is equivalent to the problem of searching (or "learning") the optimal spacecraft steering strategy. An artificial neural network is used to implement such a spacecraft steering strategy. It can be regarded as a parameterized function (the network function) that is defined by the internal network parameters. Therefore, each distinct set of network parameters defines a different network function and thus a different steering strategy. The problem of searching the optimal steering strategy is now equivalent to the problem of searching the optimal set of network parameters. Evolutionary algorithms that work on a population of (artificial) chromosomes are used to find the optimal network parameters, because the parameters can be easily mapped onto a chromosome. The trajectory optimization problem is solved when the optimal chromosome is found. A comparison of solar sail trajectories that have been published by others [2, 3, 4, 5] with ENC-trajectories has shown that ENCs can be successfully applied for near-globally optimal spacecraft control [1, 6] and that they are able to find trajectories that are closer to the (unknown) global optimum, because they explore the trajectory search space more exhaustively than a human expert can do. The obtained trajectories are fairly accurate with respect to the terminal constraint. If a more accurate trajectory is required, the ENC-solution can be used as an initial guess for a local trajectory optimization method. Using ENC, low-thrust trajectories can be optimized without an initial guess and without expert attendance. Here, new results for nuclear electric spacecraft and for solar sail spacecraft are presented and it will be shown that ENCs find very good trajectories even for very difficult problems. Trajectory optimization results are presented for 1. NASA's Solar Polar Imager Mission, a mission to attain a highly inclined close solar orbit with a solar sail [7] 2. a mission to de ect asteroid Apophis with a solar sail from a retrograde orbit with a very-high velocity impact [8, 9] 3. JPL's \2nd Global Trajectory Optimization Competition", a grand tour to visit four asteroids from different classes with a NEP spacecraft Y1 - 2007 ER - TY - JOUR A1 - Göddeke, Dominik A1 - Strzodka, Robert A1 - Mohd-Yusof, Jamaludin A1 - McCormick, Patrick A1 - Buijssen, Sven H.M. A1 - Grajewski, Matthias A1 - Turek, Stefan T1 - Exploring weak scalability for FEM calculations on a GPU-enhanced cluster JF - Parallel Computing Y1 - 2007 U6 - https://doi.org/10.1016/j.parco.2007.09.002 SN - 0167-8191 VL - 33 IS - 10-11 SP - 685 EP - 699 ER - TY - JOUR A1 - Heuermann, Holger A1 - Erkens, H. T1 - Mixed-Mode Chain Scattering Parameters: Theory and Verification JF - IEEE Transactions on Microwave Theory and Techniques N2 - Chain scattering parameters or T-parameters are a useful tool for calculating cascaded two-ports. With the increasing importance of mixed-mode S-parameters, a need for converting the T-parameters from their unbalanced form into a balanced form emerges for suiting both common and differential mode waves, as well as the mode conversion. This paper presents the derivation of the equations for transformations between mixed-mode S- and T-parameters for a mixed-mode two-port. Although derived in a way very similar to monomode T-parameters, no simplifications were necessary. Measurement results exemplify the quality of the T-parameter transformation under real-life conditions. Y1 - 2007 SN - 0018-9480 U6 - https://doi.org/10.1109/TMTT.2007.902587 VL - 55 IS - 8 SP - 1704 EP - 1708 PB - IEEE CY - New York ER - TY - JOUR A1 - Poghossian, Arshak A1 - Ingebrandt, S. A1 - Abouzar, Maryam H. A1 - Schöning, Michael Josef T1 - Label-free detection of charged macromolecules by using a field-effect-based sensor platform: Experiments and possible mechanisms of signal generation JF - Applied Physics A: Materials Science & Processing. 87 (2007), H. 3 Y1 - 2007 SN - 0947-8396 N1 - Special Issue “From Surface Science to Nanoscale Devices” SP - 517 EP - 524 ER - TY - JOUR A1 - Zerlin, Kay A1 - Kasischke, Nicole A1 - Digel, Ilya A1 - Maggakis-Kelemen, Christina A1 - Temiz Artmann, Aysegül A1 - Porst, Dariusz A1 - Kayser, Peter A1 - Linder, Peter A1 - Artmann, Gerhard T1 - Structural transition temperature of hemoglobins correlates with species’ body temperature JF - European Biophysics Journal. 37 (2007), H. 1 Y1 - 2007 SN - 1432-1017 SP - 1 EP - 10 ER - TY - JOUR A1 - Ferrein, Alexander A1 - Steinbauer, Gerald A1 - McPhillips, Graeme A1 - Potgieter, Anet T1 - Establishing the RoboCup Standard League in Africa - applying for the RoboCup Standard League with a German-Austrian-South African Research Project Y1 - 2007 SP - 1 EP - 5 ER - TY - JOUR A1 - Poghossian, Arshak A1 - Schöning, Michael Josef T1 - Chemical and biological field-effect sensors for liquids – a status report JF - Handbook of biosensors and biochips / ed. Robert S. Marks ... Bd. 1 Y1 - 2007 SN - 978-0-470-01905-4 SP - 395 EP - 412 PB - Wiley CY - Chichester ER - TY - JOUR A1 - Lohse, Wolfram T1 - Stahlbau JF - Wendehorst Beispiele aus der Baupraxis / Wetzell, Otto W. ; Baumgartner, Herwig ; Wendehorst, Reinhard [Hrsg.]. Y1 - 2007 SN - 978-3-8351-0069-5 N1 - Kapitel 6 SP - 129 EP - 167 PB - Teubner CY - Wiesbaden ER - TY - JOUR A1 - Fabo, Sabine T1 - Parasitäre Strategien : die Kunst der (un)freundlichen Übernahme JF - Kunstforum International Y1 - 2007 SN - 0177-3674 VL - 2007 IS - 185 SP - 138 EP - 163 ER - TY - JOUR A1 - Schöning, Michael Josef A1 - Abouzar, Maryam H. A1 - Poghossian, Arshak A1 - Han, Yinhua A1 - Offenhäusser, Andreas A1 - Ingebrandt, Sven T1 - Markierungsfreie DNA-Detektion mit Silizium-Feldeffekt-Sensoren – Messeffekte oder Artefakte? JF - tm - Technisches Messen . 74 (2007), H. 9 Y1 - 2007 SN - 0171-8096 SP - 466 EP - 476 ER - TY - CHAP A1 - Tippkötter, Nils A1 - Stückmann, H. A1 - Winkelmann, G. A1 - Noack, U. A1 - Beutel, S. A1 - Scheper, T. A1 - Ulber, Roland T1 - Optimisation of antibody-labelling of gold colloids for their application in an immunchromatographic assay for microcystin-LR T2 - European BioPerspectives : celebrating the 25th DECHEMA annual convention of biotechnologists ; 30 May - 1 June 2007, Cologne, Germany ; book of abstracts ; abstracts, poster programme Y1 - 2007 SP - 126 PB - Dechema CY - Frankfurt am Main ER - TY - JOUR A1 - Ferrein, Alexander A1 - Beck, Daniel A1 - Lakemeyer, Gerhard T1 - A Simulation Environment for Middle-Size Robots with Multi-level Abstraction / Beck, Daniel ; Ferrein, Alexander ; Lakemeyer, Gerhard JF - RoboCup 2007: Robot Soccer World Cup XI Y1 - 2007 SN - 978-3-540-68846-4 N1 - Lecture Notes in Computer Science ; 5001 SP - 136 EP - 147 PB - Springer CY - Berlin ER - TY - JOUR A1 - Heuermann, Holger A1 - Sadeghfam, Arash T1 - On the design of multimode integrated circuits in multilayered processes / Sadeghfam, A. ; Heuermann, H. JF - European Microwave Conference, 2007, 9-12 Oct. 2007 Y1 - 2007 SN - 978-2-87487-001-9 N1 - EuMC 2007 ; European Microwave Conference ; (37 : ; 2007.10.09-12 : ; Munich) SP - 516 EP - 519 ER - TY - JOUR A1 - Ingebrandt, S. A1 - Han, Y. A1 - Nakamura, F. A1 - Poghossian, Arshak A1 - Schöning, Michael Josef A1 - Offenhäusser, A. T1 - Label-free detection of single nucleotide polymorphisms utilizing the differential transfer function of field-effect transistors JF - Biosensors and Bioelectronics. 22 (2007), H. 12 Y1 - 2007 SN - 0956-5663 SP - 2834 EP - 2840 ER - TY - CHAP A1 - Ritz, Thomas ED - König-Ries, Brigitta T1 - Die benutzerzentrierte Entwicklung mobiler Unternehmenssoftware T2 - MMS 2007: Mobilität und mobile Informationssysteme : 2nd conference of GI-Fachgruppe MMS ; March 6th, 2007 in Aachen, Germany Y1 - 2007 SN - 978-3-88579-198-0 SP - 23 EP - 35 PB - Ges. für Informatik CY - Bonn ER - TY - JOUR A1 - Poghossian, Arshak A1 - Abouzar, Maryam H. A1 - Christiaens, P. A1 - Williams, O. A. A1 - Haenen, K. A1 - Wagner, P. A1 - Schöning, Michael Josef T1 - Nanocrystalline diamond-based field-effect (bio-)chemical sensor JF - 8. Dresdner Sensor-Symposium : Sensoren für Umwelt, Klima und Sicherheit, Biosensoren und Biosysteme, Sensoren und Sensorsysteme für die Prozesstechnik, Trends in der Sensortechnik, Materialentwicklung für die Sensorik; 8. Dresdner Sensor-Symposium, 10. - 12. Dezember 2007, Dresden / Gerald Gerlach ... (Hg.) Y1 - 2007 SN - 978-3-940046-45-1 N1 - Dresdner Sensor-Symposium <8, 2007, Dresden> ; Dresdner Beiträge zur Sensorik ; 29 SP - 191 EP - 194 PB - TUDpress, Verl. der Wissenschaften CY - Dresden ER - TY - CHAP A1 - Wellmer, Georg A1 - Chen, B.-H. A1 - Braun, Carsten A1 - Ballmann, Josef T1 - Numerical prediction of aeroelastic effects on twin-sting-rig mounted models for rear fuselage and empennage flow investigation in transonic windtunnel T2 - Proceedings / IFASD 2007, CEAS/AIAA/KTH International Forum on Aeroelasticity and Structural Dynamics, June 18 - 21, 2007, Stockholm, Sweden Y1 - 2007 PB - KTH CY - Stockholm ER - TY - JOUR A1 - Poghossian, Arshak A1 - Abouzar, Maryam H. A1 - Amberger, F. A1 - Mayer, D. A1 - Han, Y. A1 - Ingebrandt, S. A1 - Offenhäusser, A. A1 - Schöning, Michael Josef T1 - Field-effect sensors with charged macromolecules: Characterisation by capacitance–voltage, constant-capacitance, impedance spectroscopy and atomic-force microscopy methods JF - Biosensors and Bioelectronics. 22 (2007), H. 9-10 Y1 - 2007 SN - 0956-5663 N1 - Selected Papers from the Ninth World Congress On Biosensors. Toronto, Canada 10 - 12 May 2006, Alice X. J . Tang SP - 2100 EP - 2107 ER - TY - BOOK A1 - Laack, Walter van T1 - To perceive the world with logic BT - Walter van Laack. [Transl. by Anneliese Wolstenholme] / 1. ed. Y1 - 2007 SN - 978-3-936624-08-3 N1 - Dt. Ausg. u.d.T.: Mit Logik die Welt begreifen ; auch als E-Book ISBN 979-3-936624-09-0 PB - van Laack CY - Aachen ER - TY - JOUR A1 - Wagner, Torsten A1 - Maris, Rob J. A1 - Ackermann, Hans-Josef A1 - Otto, Ralph A1 - Beging, Stefan A1 - Poghossian, Arshak A1 - Schöning, Michael Josef T1 - Handheld measurement device for field-effect sensor structures: Practical evaluation and limitations JF - Sensors and Actuators B: Chemical . 127 (2007), H. 1 Y1 - 2007 SN - 0925-4005 SP - 217 EP - 223 ER -