Dokument-ID Dokumenttyp Verfasser/Autoren Herausgeber Haupttitel Abstract Auflage Verlagsort Verlag Erscheinungsjahr Seitenzahl Schriftenreihe Titel Schriftenreihe Bandzahl ISBN Quelle der Hochschulschrift Konferenzname Bemerkung Quelle:Titel Quelle:Jahrgang Quelle:Heftnummer Quelle:Erste Seite Quelle:Letzte Seite URN DOI Zugriffsart Link Abteilungen OPUS4-7904 Wissenschaftlicher Artikel Arampatzis, Adamantios, ; Karamanidis, Kiros, ; Albracht, Kirsten, albracht@fh-aachen.de Adaptational responses of the human Achilles tendon by modulation of the applied cyclic strain magnitude 2007 10 Journal of Experimental Biology 210 15 2743 2753 10.1242/jeb.003814 Fachbereich Medizintechnik und Technomathematik OPUS4-4924 Wissenschaftlicher Artikel Artmann, Gerhard, artmann@fh-aachen.de; Zerlin, Kay, zerlin@fh-aachen.de; Digel, Ilya, digel@fh-aachen.de; Stadler, Andreas M., Physical discontinuities at body temperature in human red blood cells / Artmann, GM ; Zerlin, K ; Digel, I ; Stadler, A ; Zaccai, G ; Temiz, AA 2007 0 Tissue Engineering. 13 (2007), H. 7 1076-3279 TERMIS-EU Meeting Abstracts London, UK September 4-7, 2007 1778 1778 bezahl http://online.liebertpub.com/toc/ten/13/7 Fachbereich Medizintechnik und Technomathematik OPUS4-4456 Wissenschaftlicher Artikel Behbahani, Mehdi, behbahani@fh-aachen.de; Behr, M., ; Bischof, F., ; Wolf, G. E., Kranken Herzen helfen - Ingenieure und Informatiker entwickeln gemeinsam eine Miniaturblutpumpe / Behbahani, M. ; Behr, M. ; Bischof, F. ; Wolf, G. E. 2007 2 RWTH-Themen (2007) 0179-079X 44 46 weltweit http://www.rwth-aachen.de/global/show_document.asp?id=aaaaaaaaaaaszfj Fachbereich Medizintechnik und Technomathematik OPUS4-4455 Wissenschaftlicher Artikel Behbahani, Mehdi, behbahani@fh-aachen.de; Nicolai, M., ; Probst, M., ; Behr, M., Simulation of Blood Flow in a Ventricular Assist Device 2007 3 inSIDE. 5 (2007), H. 1 28 31 Fachbereich Medizintechnik und Technomathematik OPUS4-10099 Konferenzveröffentlichung Dachwald, Bernd, Low-Thrust Mission Analysis and Global Trajectory Optimization Using Evolutionary Neurocontrol: New Results 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 2007 European Workshop on Space Mission Analysis ESA/ESOC, Darmstadt, Germany 10 { 12 Dec 2007 Fachbereich Luft- und Raumfahrttechnik OPUS4-3569 Wissenschaftlicher Artikel Dachwald, Bernd, dachwald@fh-aachen.de; Carnelli, I., ; Vasile, M., Optimizing low-thrust gravity assist interplanetary trajectories using evolutionary neurocontrollers / I. Carnelli ; B. Dachwald ; M. Vasile Piscataway, NJ IEEE Service Center 2007 XXVIII S., S. 3879 - 4328, 9 S. : Ill., graph. Dar IEEE Congress on Evolutionary Computation, 2007 : CEC 2007 ; 25 - 28 September 2007, Singapore 978-1-424-41339-3 ISBN 10: 1-424-41339-7 ; IEEE Congress on Evolutionary Computation <2007, Singapore> ; Institute of Electrical and Electronics Engineers ; Nebent: CEC 2007 ; Parallel als Online-Ausg. erschienen 965 972 campus http://dx.doi.org/10.1109/CEC.2007.4424574 Fachbereich Luft- und Raumfahrttechnik OPUS4-9948 Konferenzveröffentlichung Dachwald, Bernd, dachwald@fh-aachen.de; Kahle, Ralph, ; Wie, Bong, Head-on impact deflection of NEAs: a case study for 99942 Apophis Near-Earth asteroid (NEA) 99942 Apophis provides a typical example for the evolution of asteroid orbits that lead to Earth-impacts after a close Earth-encounter that results in a resonant return. Apophis will have a close Earth-encounter in 2029 with potential very close subsequent Earth-encounters (or even an impact) in 2036 or later, depending on whether it passes through one of several less than 1 km-sized gravitational keyholes during its 2029-encounter. A pre-2029 kinetic impact is a very favorable option to nudge the asteroid out of a keyhole. The highest impact velocity and thus deflection can be achieved from a trajectory that is retrograde to Apophis orbit. With a chemical or electric propulsion system, however, many gravity assists and thus a long time is required to achieve this. We show in this paper that the solar sail might be the better propulsion system for such a mission: a solar sail Kinetic Energy Impactor (KEI) spacecraft could impact Apophis from a retrograde trajectory with a very high relative velocity (75-80 km/s) during one of its perihelion passages. The spacecraft consists of a 160 m × 160 m, 168 kg solar sail assembly and a 150 kg impactor. Although conventional spacecraft can also achieve the required minimum deflection of 1 km for this approx. 320 m-sized object from a prograde trajectory, our solar sail KEI concept also allows the deflection of larger objects. For a launch in 2020, we also show that, even after Apophis has flown through one of the gravitational keyholes in 2029, the solar sail KEI concept is still feasible to prevent Apophis from impacting the Earth, but many KEIs would be required for consecutive impacts to increase the total Earth-miss distance to a safe value 2007 11 Planetary Defense Conference 2007 Planetary Defense Conference 2007, Wahington D.C., USA, 05-08 March 2007 1 12 Weltweit http://spacesailing.net/paper/200703_washington_dachwaldkahlewie.pdf Fachbereich Luft- und Raumfahrttechnik OPUS4-3565 Wissenschaftlicher Artikel Dachwald, Bernd, dachwald@fh-aachen.de; MacDonald, Malcolm, ; McInnes, Colin R., Heliocentric Solar Sail Orbit Transfers with Locally Optimal Control Laws / Malcolm Macdonald ; Colin McInnes ; Bernd Dachwald 2007 3 Journal of Spacecraft and Rockets. 44 (2007), H. 1 0022-4650 273 276 campus http://dx.doi.org/10.2514/1.17297 Fachbereich Luft- und Raumfahrttechnik OPUS4-3525 Wissenschaftlicher Artikel Dachwald, Bernd, dachwald@fh-aachen.de; McDonald, Malcolm, ; McInnes, Colin R., ; Mengali, Giovanni, Impact of Optical Degradation on Solar Sail Mission Performance 2007 9 Journal of Spacecraft and Rockets. 44 (2007), H. 4 0022-4650 2. ISSN: 1533-6794 740 749 campus http://dx.doi.org/10.2514/1.21432 Fachbereich Luft- und Raumfahrttechnik OPUS4-9971 Konferenzveröffentlichung Dachwald, Bernd, Dachwald@fh-aachen.de; Mengali, Giovanni, ; Quarta, Alessandro A, ; Macdonald, Malcolm, ; McInnes, Colin R, Optical solar sail degradation modelling We propose a simple parametric OSSD model that describes the variation of the sail film's optical coefficients with time, depending on the sail film's environmental history, i.e., the radiation dose. The primary intention of our model is not to describe the exact behavior of specific film-coating combinations in the real space environment, but to provide a more general parametric framework for describing the general optical degradation behavior of solar sails. 2007 27 1st International Symposium on Solar Sailing 1st International Symposium on Solar Sailing 27-29 June 2007, Herrsching, Germany 1 27 http://www.isss.spacesailing.net/ Fachbereich Luft- und Raumfahrttechnik OPUS4-3564 Wissenschaftlicher Artikel Dachwald, Bernd, dachwald@fh-aachen.de; Mengali, Giovanni, ; Quarta, Alessandro A., ; Circi, Christian, Refined Solar Sail Force Model with Mission Application / Giovanni Mengali ; Alessandro A. Quarta , Christian Circi ; Bernd Dachwald 2007 8 Journal of Guidance, Control, and Dynamics. 30 (2007), H. 2 0162-3192 2. ISBN: 0731-5090 512 520 campus http://dx.doi.org/10.2514/1.24779 Fachbereich Luft- und Raumfahrttechnik OPUS4-3507 Wissenschaftlicher Artikel Dachwald, Bernd, dachwald@fh-aachen.de; Ohndorf, A., 1st ACT Global Trajectory Optimisation Competition : Results found at DLR 2007 10 Acta Astronautica. 61 (2007), H. 9 0094-5765 Global Trajectory Optimization ; Results of the First Competition Organised by the Advanced Concept Team (ACT) of the European Space Agency (ESA) 742 752 campus http://dx.doi.org/10.1016/j.actaastro.2007.03.011 Fachbereich Luft- und Raumfahrttechnik OPUS4-10090 Konferenzveröffentlichung Dachwald, Bernd, Dachwald@fh-aachen.de; Seboldt, Wolfgang, ; Loeb, Horst W., ; Schartner, Karl-Heinz, A comparison of SEP and NEP for a main belt asteroid sample return mission Innovative interplanetary deep space missions, like a main belt asteroid sample return mission, require ever larger velocity increments (∆V s) and thus ever more demanding propulsion capabilities. Providing much larger exhaust velocities than chemical high-thrust systems, electric low-thrust space-propulsion systems can significantly enhance or even enable such high-energy missions. In 1995, a European-Russian Joint Study Group (JSG) presented a study report on "Advanced Interplanetary Missions Using Nuclear-Electric Propulsion" (NEP). One of the investigated reference missions was a sample return (SR) from the main belt asteroid (19) Fortuna. The envisaged nuclear power plant, Topaz-25, however, could not be realized and also the worldwide developments in space reactor hardware stalled. In this paper, we investigate, whether such a mission is also feasible using a solar electric propulsion (SEP) system and compare our SEP results to corresponding NEP results. 2007 10 7th International Symposium on Launcher Technologies, Barcelona, Spain, 02-05 April 2007 1 10 weltweit http://spacesailing.net/paper/200704_Barcelona_DachwaldSeboldtLoebSchartner.pdf Fachbereich Luft- und Raumfahrttechnik OPUS4-3526 Wissenschaftlicher Artikel Dachwald, Bernd, dachwald@fh-aachen.de; Wi, Bong, Solar Sail Kinetic Energy Impactor Trajectory Optimization for an Asteroid-Deflection Mission 2007 9 Journal of Spacecraft and Rockets. 44 (2007), H. 4 0022-4650 2. ISSN: 1533-6794 755 764 campus http://dx.doi.org/10.2514/1.22586 Fachbereich Luft- und Raumfahrttechnik OPUS4-4908 Wissenschaftlicher Artikel Digel, Ilya, digel@fh-aachen.de; Kurulgan Demirci, Eylem, ; Linder, Peter, linder@fh-aachen.de; Kayser, Peter, kayser@fh-aachen.de Decrease in extracellular collagen crosslinking after NMR magnetic field application in skin fibroblasts 2007 6 Medical and Biological Engineering and Computing. 45 (2007), H. 1 1741-0444 91 97 campus http://dx.doi.org/10.1007/s11517-006-0144-z Fachbereich Medizintechnik und Technomathematik OPUS4-4906 Wissenschaftlicher Artikel Digel, Ilya, digel@fh-aachen.de; Zerlin, Kay, zerlin@fh-aachen.de; Temiz Artmann, Aysegül, a.artmann@fh-aachen.de; Engels, S., Protein dynamics in thermosensation 2007 0 Regenerative medicine. 2 (2007), H. 5 1746-0751 Proceedings of the 3rd World Congress on Regenerative Medicine. October 18-20, 2007. Leipzig, Germany 533 533 bezahl http://dx.doi.org/10.2217/17460751.2.5.485 Fachbereich Medizintechnik und Technomathematik OPUS4-3832 Wissenschaftlicher Artikel Erbayraktar, Zubeyde, ; Yilmaz, Osman, ; Temiz Artmann, Aysegül, a.artmann@fh-aachen.de; Cehreli, Ruksan, ; Coker, Canan, Effects of Selenium Supplementation on Antioxidant Defense and Glucose Homeostasis in Experimental Diabetes Mellitus 2007 9 Biological Trace Element Research 118 3 217 226 campus http://dx.doi.org/10.1007/s12011-007-0037-5 Fachbereich Medizintechnik und Technomathematik OPUS4-3380 Wissenschaftlicher Artikel Eschweiler, J., ; Laack, Walter van, Dr.vanLaack@web.de; Staat, Manfred, m.staat@fh-aachen.de Elektromyographische Untersuchungen zur Kräftigung der Oberschenkelmuskulatur mit einem myoelektrischen Stimulator nach arthroskopischen Eingriffen am Kniegelenk 2007 3 Orthopädische Praxis. 43 (2007), H. 10 0030-588x 539 542 Fachbereich Medizintechnik und Technomathematik OPUS4-7133 Wissenschaftlicher Artikel Kotliar, Konstantin, kotliar@fh-aachen.de; Drozdova, G. A., ; Shamshinova, A. M., Ocular hemodinamics and contemporary methods of its assessment. Part III. Non-invasive methods of assessment of ocular blood flow. 2. Static and dynamic assessment of retinal vessel reaction to stimuli 2007 7 National Journal Glaucoma Vol. 6 No. 2 64 71 Fachbereich Medizintechnik und Technomathematik OPUS4-7135 Wissenschaftlicher Artikel Kotliar, Konstantin, kotliar@fh-aachen.de; Drozdova, G. A., ; Shamshinova, A. M., Ocular hemodinamics and contemporary methods of its assessment. Part III. Non-invasive methods of assessment of ocular blood flow. 1. Assessment of blood cell velocities and flow rates in intraocular vessels and vascular beds 2007 7 Journal of Glaucoma Vol. 6 1 61 68 Fachbereich Medizintechnik und Technomathematik