@inproceedings{StadlerEmbsZerlinetal.2007, author = {Stadler, Andreas M. and Embs, Jan P. and Zerlin, Kay and Digel, Ilya and Artmann, Gerhard and Zaccai, Joe and B{\"u}ldt, Georg}, title = {Temperature transitions of hemoglobin and cytosolic water diffusion in human red blood cells : [poster]}, year = {2007}, abstract = {Background Hemoglobin interactions in red blood cells Hemoglobin dynamics in human red blood cells Diffusion of H2O in red blood cells}, subject = {Erythrozyt}, language = {en} } @inproceedings{ReimerBraunChenetal.2007, author = {Reimer, Lars and Braun, Carsten and Chen, B.-H. and Ballmann, Josef}, title = {Computational aeroelastic analysis and design of the HIRENASD wind tunnel wing model and tests}, series = {Proceedings / IFASD 2007, CEAS/AIAA/KTH International Forum on Aeroelasticity and Structural Dynamics : June 18 - 21, 2007, Stockholm, Sweden}, booktitle = {Proceedings / IFASD 2007, CEAS/AIAA/KTH International Forum on Aeroelasticity and Structural Dynamics : June 18 - 21, 2007, Stockholm, Sweden}, publisher = {KTH}, address = {Stockholm}, pages = {1 CD-ROM}, year = {2007}, language = {en} } @article{DachwaldMengaliQuartaetal.2007, author = {Dachwald, Bernd and Mengali, Giovanni and Quarta, Alessandro A. and Circi, Christian}, title = {Refined Solar Sail Force Model with Mission Application / Giovanni Mengali ; Alessandro A. Quarta , Christian Circi ; Bernd Dachwald}, series = {Journal of Guidance, Control, and Dynamics. 30 (2007), H. 2}, journal = {Journal of Guidance, Control, and Dynamics. 30 (2007), H. 2}, isbn = {0162-3192}, pages = {512 -- 520}, year = {2007}, language = {en} } @inproceedings{DachwaldMengaliQuartaetal.2007, author = {Dachwald, Bernd and Mengali, Giovanni and Quarta, Alessandro A and Macdonald, Malcolm and McInnes, Colin R}, title = {Optical solar sail degradation modelling}, series = {1st International Symposium on Solar Sailing}, booktitle = {1st International Symposium on Solar Sailing}, pages = {1 -- 27}, year = {2007}, abstract = {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.}, language = {en} } @article{KapplerTanudyayaSchmittTippkoetteretal.2007, author = {Kappler-Tanudyaya, Nathalie and Schmitt, Heike and Tippk{\"o}tter, Nils and Meyer, Lina and Lenzen, Sigurd and Ulber, Roland}, title = {Combination of biotransformation and chromatography for the isolation and purification of mannoheptulose}, series = {Biotechnology Journal}, volume = {2}, journal = {Biotechnology Journal}, number = {6}, issn = {1860-7314}, doi = {10.1002/biot.200700004}, pages = {692 -- 699}, year = {2007}, abstract = {Mannoheptulose is a seven-carbon sugar. It is an inhibitor of glucose-induced insulin secretion due to its ability to selectively inhibit the enzyme glucokinase. An improved procedure for mannoheptulose isolation from avocados is described in this study (based upon the original method by La Forge). The study focuses on the combination of biotransformation and downstream processing (preparative chromatography) as an efficient method to produce a pure extract of mannoheptulose. The experiments were divided into two major phases. In the first phase, several methods and parameters were compared to optimize the mannoheptulose extraction with respect to efficiency and purity. In the second phase, a mass balance of mannoheptulose over the whole extraction process was undertaken to estimate the yield and efficiency of the total extraction process. The combination of biotransformation and preparative chromatography allowed the production of a pure mannoheptulose extract. In a biological test, the sugar inhibited the glucokinase enzyme activity efficiently.}, language = {en} } @inproceedings{TranStaatKreissig2007, author = {Tran, Thanh Ngoc and Staat, Manfred and Kreißig, R.}, title = {Finite element shakedown and limit reliability analysis of thin shells}, year = {2007}, abstract = {A procedure for the evaluation of the failure probability of elastic-plastic thin shell structures is presented. The procedure involves a deterministic limit and shakedown analysis for each probabilistic iteration which is based on the kinematical approach and the use the exact Ilyushin yield surface. Based on a direct definition of the limit state function, the non-linear problems may be efficiently solved by using the First and Second Order Reliabiblity Methods (Form/SORM). This direct approach reduces considerably the necessary knowledge of uncertain technological input data, computing costs and the numerical error. In: Computational plasticity / ed. by Eugenio Onate. Dordrecht: Springer 2007. VII, 265 S. (Computational Methods in Applied Sciences ; 7) (COMPLAS IX. Part 1 . International Center for Numerical Methods in Engineering (CIMNE)). ISBN 978-1-402-06576-7 S. 186-189}, subject = {Finite-Elemente-Methode}, language = {en} } @article{VuStaatTran2007, author = {Vu, Duc Khoi and Staat, Manfred and Tran, Ich Thinh}, title = {Analysis of pressure equipment by application of the primal-dual theory of shakedown}, series = {Communications in Numerical Methods in Engineering. 23 (2007), H. 3}, journal = {Communications in Numerical Methods in Engineering. 23 (2007), H. 3}, isbn = {1069-8299}, pages = {213 -- 225}, year = {2007}, language = {en} } @inproceedings{BreitbachAlexopoulosHoffschmidt2007, author = {Breitbach, Gerd and Alexopoulos, Spiros and Hoffschmidt, Bernhard}, title = {Fluid flow in porous ceramic multichannel crossflower filter modules}, publisher = {COMSOL Inc.}, address = {Burlington, Mass.}, pages = {5 S.}, year = {2007}, language = {en} } @article{StaatVu2007, author = {Staat, Manfred and Vu, Duc-Khoi}, title = {Limit analysis of flaws in pressurized pipes and cylindrical vessels. Part I: Axial defects}, series = {Engineering Fracture Mechanics. 74 (2007), H. 3}, journal = {Engineering Fracture Mechanics. 74 (2007), H. 3}, isbn = {0013-7944}, pages = {431 -- 450}, year = {2007}, language = {en} } @inproceedings{GoemmelButenwegKob2007, author = {G{\"o}mmel, A. and Butenweg, Christoph and Kob, M.}, title = {A fluid-structure interaction model of vocal fold oscillation}, series = {5th International Workshop on Models and Analysis of Vocal Emissions for Biomedical Applications, MAVEBA 2007}, booktitle = {5th International Workshop on Models and Analysis of Vocal Emissions for Biomedical Applications, MAVEBA 2007}, isbn = {978-888453674-7}, pages = {127 -- 128}, year = {2007}, abstract = {Since fluid-structure interaction within the finite-element method is state of the art in many engineering fields, this method is used in voice analysis. A quasi two-dimensional model of the vocal folds including the ventricular folds is presented. First results of self-sustained vocal fold oscillation are presented and possibilities as well as limitations are discussed.}, language = {en} } @article{VuStaat2007, author = {Vu, Duc Khoi and Staat, Manfred}, title = {Shakedown analysis of structures made of materials with temperature-dependent yield stress}, series = {International Journal of Solids and Structures. 44 (2007), H. 13}, journal = {International Journal of Solids and Structures. 44 (2007), H. 13}, isbn = {0020-7683}, pages = {4524 -- 4540}, year = {2007}, language = {en} } @article{DachwaldCarnelliVasile2007, author = {Dachwald, Bernd and Carnelli, I. and Vasile, M.}, title = {Optimizing low-thrust gravity assist interplanetary trajectories using evolutionary neurocontrollers / I. Carnelli ; B. Dachwald ; M. Vasile}, series = {IEEE Congress on Evolutionary Computation, 2007 : CEC 2007 ; 25 - 28 September 2007, Singapore}, journal = {IEEE Congress on Evolutionary Computation, 2007 : CEC 2007 ; 25 - 28 September 2007, Singapore}, publisher = {IEEE Service Center}, address = {Piscataway, NJ}, isbn = {978-1-424-41339-3}, pages = {965 -- 972}, year = {2007}, language = {en} } @article{DigelZerlinTemizArtmannetal.2007, author = {Digel, Ilya and Zerlin, Kay and Temiz Artmann, Ayseg{\"u}l and Engels, S.}, title = {Protein dynamics in thermosensation}, series = {Regenerative medicine. 2 (2007), H. 5}, journal = {Regenerative medicine. 2 (2007), H. 5}, isbn = {1746-0751}, pages = {533 -- 533}, year = {2007}, language = {en} } @article{DachwaldMcDonaldMcInnesetal.2007, author = {Dachwald, Bernd and McDonald, Malcolm and McInnes, Colin R. and Mengali, Giovanni}, title = {Impact of Optical Degradation on Solar Sail Mission Performance}, series = {Journal of Spacecraft and Rockets. 44 (2007), H. 4}, journal = {Journal of Spacecraft and Rockets. 44 (2007), H. 4}, isbn = {0022-4650}, pages = {740 -- 749}, year = {2007}, language = {en} } @article{HeuermannIbrahimHillebrand2007, author = {Heuermann, Holger and Ibrahim, Irfan and Hillebrand, J.}, title = {Vector-Signal-Generator with Two ?'?'-PLL's / Ibrahim, I. ; Hillebrand, J. ; Heuermann, H.}, series = {European Conference on Wireless Technologies, 2007. ECWT 2007 ; 8 - 10 October 2007 Munich, Germany}, journal = {European Conference on Wireless Technologies, 2007. ECWT 2007 ; 8 - 10 October 2007 Munich, Germany}, isbn = {978-2-87487-003-3}, pages = {1 -- 4}, year = {2007}, language = {en} } @article{DachwaldWi2007, author = {Dachwald, Bernd and Wi, Bong}, title = {Solar Sail Kinetic Energy Impactor Trajectory Optimization for an Asteroid-Deflection Mission}, series = {Journal of Spacecraft and Rockets. 44 (2007), H. 4}, journal = {Journal of Spacecraft and Rockets. 44 (2007), H. 4}, isbn = {0022-4650}, pages = {755 -- 764}, year = {2007}, language = {en} } @article{DachwaldMacDonaldMcInnes2007, author = {Dachwald, Bernd and MacDonald, Malcolm and McInnes, Colin R.}, title = {Heliocentric Solar Sail Orbit Transfers with Locally Optimal Control Laws / Malcolm Macdonald ; Colin McInnes ; Bernd Dachwald}, series = {Journal of Spacecraft and Rockets. 44 (2007), H. 1}, journal = {Journal of Spacecraft and Rockets. 44 (2007), H. 1}, isbn = {0022-4650}, pages = {273 -- 276}, year = {2007}, language = {en} } @inproceedings{TranStaatKreissig2007, author = {Tran, Thanh Ngoc and Staat, Manfred and Kreißig, R.}, title = {Calculation of load carrying capacity of shell structures with elasto-plastic material by direct methods}, year = {2007}, abstract = {Proceedings of the International Conference on Material Theory and Nonlinear Dynamics. MatDyn. Hanoi, Vietnam, Sept. 24-26, 2007, 8 p. In this paper, a method is introduced to determine the limit load of general shells using the finite element method. The method is based on an upper bound limit and shakedown analysis with elastic-perfectly plastic material model. A non-linear constrained optimisation problem is solved by using Newton's method in conjunction with a penalty method and the Lagrangean dual method. Numerical investigation of a pipe bend subjected to bending moments proves the effectiveness of the algorithm.}, subject = {Finite-Elemente-Methode}, language = {en} } @inproceedings{Matcha2007, author = {Matcha, Heike}, title = {Parametric possibilities: designing with parametric modelling}, series = {Predicting the Future [25th eCAADe Conference Proceedings]}, booktitle = {Predicting the Future [25th eCAADe Conference Proceedings]}, isbn = {978-0-9541183-6-5}, pages = {849 -- 856}, year = {2007}, language = {en} } @article{ArampatzisKaramanidisAlbracht2007, author = {Arampatzis, Adamantios and Karamanidis, Kiros and Albracht, Kirsten}, title = {Adaptational responses of the human Achilles tendon by modulation of the applied cyclic strain magnitude}, series = {Journal of Experimental Biology}, volume = {210}, journal = {Journal of Experimental Biology}, number = {15}, issn = {0022-0949}, doi = {10.1242/jeb.003814}, pages = {2743 -- 2753}, year = {2007}, language = {en} } @article{ReinhardtBitzElOuardietal.2007, author = {Reinhardt, T. and Bitz, Andreas and El Ouardi, A. and Streckert, J. and Sommer, A. and Lerchl, A. and Hansen, V.}, title = {Exposure set-ups for in vivo experiments using radial waveguides}, series = {Radiation Protection Dosimetry}, volume = {124}, journal = {Radiation Protection Dosimetry}, number = {1}, issn = {1742-3406}, doi = {10.1093/rpd/ncm370}, pages = {21 -- 26}, year = {2007}, language = {en} } @article{SommerBitzStreckertetal.2007, author = {Sommer, Angela M. and Bitz, Andreas and Streckert, Joachim and Hansen, Volkert W. and Lerchl, Alexander}, title = {Lymphoma development in mice chronically exposed to UMTS-modulated radiofrequency electromagnetic fields}, series = {Radiation Research}, volume = {168}, journal = {Radiation Research}, number = {1}, issn = {1938-5404}, doi = {10.1667/RR0857.1}, pages = {72 -- 80}, year = {2007}, language = {en} } @article{PaulssenKueckmannAbram2007, author = {Paulßen, Elisabeth and K{\"u}ckmann, Theresa and Abram, Ulrich}, title = {Silver(I) Complexes of 1,3-Dialkyl-4,5-dimethylimidazol-2-ylidenes and their Use as Precursors for the Synthesis of Rhenium(V) NHC Complexes}, series = {Zeitschrift f{\"u}r anorganische und allgemeine Chemie : ZAAC = Journal of inorganic and general chemistry}, volume = {633}, journal = {Zeitschrift f{\"u}r anorganische und allgemeine Chemie : ZAAC = Journal of inorganic and general chemistry}, number = {5-6}, issn = {1521-3749}, doi = {10.1002/zaac.200700021}, pages = {830 -- 834}, year = {2007}, language = {en} } @inproceedings{SchuhGottschalkNarretal.2007, author = {Schuh, G{\"u}nther and Gottschalk, Sebastian Friedrich and Narr, Claus and H{\"o}hne, Tim}, title = {Adaptive logistics : information management for planning and control of small series assembly}, series = {2nd International Conference on Changeable, Agile, Reconfigurable and Virtual Production (CARV 2007), Toronto, Ontario, Canada, 22-24 July 2007 : Book of Abstracts}, booktitle = {2nd International Conference on Changeable, Agile, Reconfigurable and Virtual Production (CARV 2007), Toronto, Ontario, Canada, 22-24 July 2007 : Book of Abstracts}, editor = {Z{\"a}h, Michael F.}, isbn = {978-0-9783187-0-3}, pages = {212 -- 221}, year = {2007}, language = {en} } @article{SchuhGottschalkHoehne2007, author = {Schuh, G. and Gottschalk, S. and H{\"o}hne, Tim}, title = {High Resolution Production Management}, series = {CIRP Annals}, volume = {56}, journal = {CIRP Annals}, number = {1}, issn = {0007-8506}, doi = {10.1016/j.cirp.2007.05.105}, pages = {439 -- 442}, year = {2007}, language = {en} } @inproceedings{DrummSchmittDoetal.2007, author = {Drumm, Christian and Schmitt, Matthias and Do, Hong-Hai and Rahm, Erhard}, title = {Quickmig: automatic schema matching for data migration projects}, series = {Proceedings of the 2007 ACM Conference on Information and Knowledge Management / CIKM'07, Lisboa, Portugal, Nov. 6 - 10, 2007}, booktitle = {Proceedings of the 2007 ACM Conference on Information and Knowledge Management / CIKM'07, Lisboa, Portugal, Nov. 6 - 10, 2007}, isbn = {978-1-59593-803-9}, doi = {10.1145/1321440.1321458}, pages = {107 -- 116}, year = {2007}, language = {en} } @inproceedings{WeberMarkovicDrumm2007, author = {Weber, Ingo and Markovic, Ivan and Drumm, Christian}, title = {A conceptual framework for composition in business process management}, series = {Business Information Systems : 10th International Conference, BIS 2007, Poznan, Poland, April 25-27, 2007. Proceedings}, booktitle = {Business Information Systems : 10th International Conference, BIS 2007, Poznan, Poland, April 25-27, 2007. Proceedings}, publisher = {Springer}, address = {Berlin, Heidelberg}, isbn = {978-3-540-72035-5}, doi = {10.1007/978-3-540-72035-5_5}, pages = {54 -- 66}, year = {2007}, language = {en} } @incollection{DrummLemckeOberle2007, author = {Drumm, Christian and Lemcke, Jens and Oberle, Daniel}, title = {Business Process Management And Semantic Technologies}, series = {The Semantic Web}, booktitle = {The Semantic Web}, publisher = {Springer}, address = {Boston, MA}, isbn = {978-0-387-48531-7}, doi = {10.1007/978-0-387-48531-7_10}, pages = {207 -- 239}, year = {2007}, language = {en} } @phdthesis{Trzewik2007, author = {Trzewik, J{\"u}rgen}, title = {Experimental analysis of biaxial mechanical tension in cell monolayers and cultured three-dimensional tissues: the celldrum technology}, publisher = {Univerist{\"a}tsverlg Ilmenau}, address = {Ilmenau}, year = {2007}, language = {en} } @article{WallerBraunHojdisetal.2007, author = {Waller, Mark P. and Braun, Heiko and Hojdis, Nils and B{\"u}hl, Michael}, title = {Geometries of Second-Row Transition-Metal Complexes from Density-Functional Theory}, series = {Journal of Chemical Theory and Computation}, volume = {3}, journal = {Journal of Chemical Theory and Computation}, number = {6}, issn = {1549-9626}, doi = {10.1021/ct700178y}, pages = {2234 -- 2242}, year = {2007}, language = {en} } @article{KrollLudwigs2007, author = {Kroll-Ludwigs, Kathrin}, title = {The Reform of German Maintenance Law}, series = {The International Survey of Family Law}, journal = {The International Survey of Family Law}, pages = {85 -- 100}, year = {2007}, language = {en} } @incollection{ReimerBraunBallmann2007, author = {Reimer, Lars and Braun, Carsten and Ballmann, Josef}, title = {Computational study of the aeroelastic equilibrium configuration of a swept wind tunnel wing model in subsonic flow}, series = {High performance computing in science and engineering '06. Transactions of the High Performance Computing Center Stuttgart (HLRS) 2006 / Wolfgang E. Nagel ... Eds.}, booktitle = {High performance computing in science and engineering '06. Transactions of the High Performance Computing Center Stuttgart (HLRS) 2006 / Wolfgang E. Nagel ... Eds.}, publisher = {Springer}, address = {Berlin [u.a.]}, isbn = {978-3-540-36165-7}, pages = {421 -- 434}, year = {2007}, abstract = {In the Collaborative Research Center SFB 401 at RWTH Aachen University, the numerical aeroelastic method SOFIA for direct numerical aeroelastic simulation is being progressively developed. Numerical results obtained by applying SOFIA were compared with measured data of static and dynamic aeroelastic wind tunnel tests for an elastic swept wing in subsonic flow.}, language = {en} } @article{MistlerAnthoineButenweg2007, author = {Mistler, Michael and Anthoine, A. and Butenweg, Christoph}, title = {In-plane and out-of-plane homogenisation of masonry}, series = {Computers \& structures}, volume = {Volume 85}, journal = {Computers \& structures}, number = {Issues 17-18}, issn = {1879-2243 (E-Journal); 0045-7949 (Print)}, doi = {10.1016/j.compstruc.2006.08.087}, pages = {1321 -- 1330}, year = {2007}, language = {en} } @article{DachwaldOhndorf2007, author = {Dachwald, Bernd and Ohndorf, A.}, title = {1st ACT Global Trajectory Optimisation Competition : Results found at DLR}, series = {Acta Astronautica. 61 (2007), H. 9}, journal = {Acta Astronautica. 61 (2007), H. 9}, isbn = {0094-5765}, pages = {742 -- 752}, year = {2007}, language = {en} } @article{GoemmelButenwegBolenderetal.2007, author = {G{\"o}mmel, Andreas and Butenweg, Christoph and Bolender, Katrin and Grunendahl, Arno}, title = {A muscle controlled finite-element model of laryngeal abduction and adduction}, series = {Computer methods in biomechanics and biomedical engineering}, volume = {Volume 10}, journal = {Computer methods in biomechanics and biomedical engineering}, number = {Issue 5}, issn = {1476-8259 (E-Journal); 1025-5842 (Print)}, pages = {377 -- 388}, year = {2007}, language = {en} } @incollection{MeskourisButenwegKalkeretal.2007, author = {Meskouris, Konstantin and Butenweg, Christoph and Kalker, Ines and Mistler, Michael}, title = {Numerical simulation of historic masonry buildings}, series = {Antike Erdbeben im alpinen und zirkumalpinen Raum : Befunde und Probleme in arch{\"a}ologischer, historischer und seismologischer Sicht ; Beitr{\"a}ge des Interdisziplin{\"a}ren Workshops Schloss Hohenkammer, 14./15. Mai 2004 = Earthquakes in antiquity in the alpine and circum-alpine region / Gerhard H. Waldherr ; Anselm Smolka (Hrsg.) (Geographica Historica ; 24)}, booktitle = {Antike Erdbeben im alpinen und zirkumalpinen Raum : Befunde und Probleme in arch{\"a}ologischer, historischer und seismologischer Sicht ; Beitr{\"a}ge des Interdisziplin{\"a}ren Workshops Schloss Hohenkammer, 14./15. Mai 2004 = Earthquakes in antiquity in the alpine and circum-alpine region / Gerhard H. Waldherr ; Anselm Smolka (Hrsg.) (Geographica Historica ; 24)}, publisher = {Franz Steiner Verlag}, address = {Stuttgart}, isbn = {978-3-515-09030-8 ; 3-515-09030-4}, pages = {171 -- 189}, year = {2007}, language = {en} } @article{ZerlinDigelStadleretal.2007, author = {Zerlin, Kay and Digel, Ilya and Stadler, Andreas M. and B{\"u}ldt, Georg and Zaccai, Guiseppe and Artmann, Gerhard}, title = {Dynamics and interactions of hemoglobin in human red blood cells and concentrated hemoglobin solutions}, series = {Regenerative medicine. 2 (2007), H. 5}, journal = {Regenerative medicine. 2 (2007), H. 5}, isbn = {1746-0751}, pages = {573 -- 573}, year = {2007}, language = {en} } @article{ArtmannZerlinDigeletal.2007, author = {Artmann, Gerhard and Zerlin, Kay and Digel, Ilya and Stadler, Andreas M.}, title = {Physical discontinuities at body temperature in human red blood cells / Artmann, GM ; Zerlin, K ; Digel, I ; Stadler, A ; Zaccai, G ; Temiz, AA}, series = {Tissue Engineering. 13 (2007), H. 7}, journal = {Tissue Engineering. 13 (2007), H. 7}, isbn = {1076-3279}, pages = {1778 -- 1778}, year = {2007}, language = {en} } @inproceedings{DachwaldSeboldtLoebetal.2007, author = {Dachwald, Bernd and Seboldt, Wolfgang and Loeb, Horst W. and Schartner, Karl-Heinz}, title = {A comparison of SEP and NEP for a main belt asteroid sample return mission}, series = {7th International Symposium on Launcher Technologies, Barcelona, Spain, 02-05 April 2007}, booktitle = {7th International Symposium on Launcher Technologies, Barcelona, Spain, 02-05 April 2007}, pages = {1 -- 10}, year = {2007}, abstract = {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.}, language = {en} } @inproceedings{DachwaldKahleWie2007, author = {Dachwald, Bernd and Kahle, Ralph and Wie, Bong}, title = {Head-on impact deflection of NEAs: a case study for 99942 Apophis}, series = {Planetary Defense Conference 2007}, booktitle = {Planetary Defense Conference 2007}, pages = {1 -- 12}, year = {2007}, abstract = {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}, language = {en} } @inproceedings{Dachwald2007, author = {Dachwald, Bernd}, title = {Low-Thrust Mission Analysis and Global Trajectory Optimization Using Evolutionary Neurocontrol: New Results}, series = {European Workshop on Space Mission Analysis ESA/ESOC, Darmstadt, Germany 10 { 12 Dec 2007}, booktitle = {European Workshop on Space Mission Analysis ESA/ESOC, Darmstadt, Germany 10 { 12 Dec 2007}, year = {2007}, abstract = {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}, language = {en} } @article{GoeddekeStrzodkaMohdYusofetal.2007, author = {G{\"o}ddeke, Dominik and Strzodka, Robert and Mohd-Yusof, Jamaludin and McCormick, Patrick and Buijssen, Sven H.M. and Grajewski, Matthias and Turek, Stefan}, title = {Exploring weak scalability for FEM calculations on a GPU-enhanced cluster}, series = {Parallel Computing}, volume = {33}, journal = {Parallel Computing}, number = {10-11}, issn = {0167-8191}, doi = {10.1016/j.parco.2007.09.002}, pages = {685 -- 699}, year = {2007}, language = {en} } @article{HeuermannErkens2007, author = {Heuermann, Holger and Erkens, H.}, title = {Mixed-Mode Chain Scattering Parameters: Theory and Verification}, series = {IEEE Transactions on Microwave Theory and Techniques}, volume = {55}, journal = {IEEE Transactions on Microwave Theory and Techniques}, number = {8}, publisher = {IEEE}, address = {New York}, isbn = {0018-9480}, doi = {10.1109/TMTT.2007.902587}, pages = {1704 -- 1708}, year = {2007}, abstract = {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.}, language = {en} } @article{PoghossianIngebrandtAbouzaretal.2007, author = {Poghossian, Arshak and Ingebrandt, S. and Abouzar, Maryam H. and Sch{\"o}ning, Michael Josef}, title = {Label-free detection of charged macromolecules by using a field-effect-based sensor platform: Experiments and possible mechanisms of signal generation}, series = {Applied Physics A: Materials Science \& Processing. 87 (2007), H. 3}, journal = {Applied Physics A: Materials Science \& Processing. 87 (2007), H. 3}, isbn = {0947-8396}, pages = {517 -- 524}, year = {2007}, language = {en} } @article{ZerlinKasischkeDigeletal.2007, author = {Zerlin, Kay and Kasischke, Nicole and Digel, Ilya and Maggakis-Kelemen, Christina and Temiz Artmann, Ayseg{\"u}l and Porst, Dariusz and Kayser, Peter and Linder, Peter and Artmann, Gerhard}, title = {Structural transition temperature of hemoglobins correlates with species' body temperature}, series = {European Biophysics Journal. 37 (2007), H. 1}, journal = {European Biophysics Journal. 37 (2007), H. 1}, isbn = {1432-1017}, pages = {1 -- 10}, year = {2007}, language = {en} } @article{ChristiaensAbouzarPoghossianetal.2007, author = {Christiaens, P. and Abouzar, Maryam H. and Poghossian, Arshak and Wagner, Torsten and Bijnens, N. and Williams, O. A. and Daenen, M. and Haenen, K. and Douth{\´e}ret, O. and Haen, J. d´ and Mekhalif, Z. and Sch{\"o}ning, Michael Josef and Wagner, P.}, title = {pH sensitivity of nanocrystalline diamond films}, series = {Physica status solidi (A). 204 (2007), H. 9}, journal = {Physica status solidi (A). 204 (2007), H. 9}, isbn = {0031-8965}, pages = {2925 -- 2930}, year = {2007}, language = {en} } @article{PoghossianAbouzarAmbergeretal.2007, author = {Poghossian, Arshak and Abouzar, Maryam H. and Amberger, F. and Mayer, D. and Han, Y. and Ingebrandt, S. and Offenh{\"a}usser, A. and Sch{\"o}ning, Michael Josef}, title = {Field-effect sensors with charged macromolecules: Characterisation by capacitance-voltage, constant-capacitance, impedance spectroscopy and atomic-force microscopy methods}, series = {Biosensors and Bioelectronics. 22 (2007), H. 9-10}, journal = {Biosensors and Bioelectronics. 22 (2007), H. 9-10}, isbn = {0956-5663}, pages = {2100 -- 2107}, year = {2007}, language = {en} } @book{Laack2007, author = {Laack, Walter van}, title = {To perceive the world with logic}, publisher = {van Laack}, address = {Aachen}, isbn = {978-3-936624-08-3}, pages = {340 S. : Ill., graph. Darst}, year = {2007}, language = {en} } @article{WagnerMarisAckermannetal.2007, author = {Wagner, Torsten and Maris, Rob J. and Ackermann, Hans-Josef and Otto, Ralph and Beging, Stefan and Poghossian, Arshak and Sch{\"o}ning, Michael Josef}, title = {Handheld measurement device for field-effect sensor structures: Practical evaluation and limitations}, series = {Sensors and Actuators B: Chemical . 127 (2007), H. 1}, journal = {Sensors and Actuators B: Chemical . 127 (2007), H. 1}, isbn = {0925-4005}, pages = {217 -- 223}, year = {2007}, language = {en} } @article{ChristiaensAbouzarPoghossianetal.2007, author = {Christiaens, P. and Abouzar, Maryam H. and Poghossian, Arshak and Wagner, Torsten and Bijnens, N. and Williams, O. A. and Daenen, M. and Haenen, K. and Sch{\"o}ning, Michael Josef and Wagner, P.}, title = {Nanocrystalline diamond-based field-effect capacitive pH sensor}, series = {Transducers '07 Eurosensors XXI : digest of technical papers ; the14th International Conference on Solid-State Sensors, Actuators and Microsystems, June 10-14, 2007, Lyon, France / Gilles Delapierre (Ed.)}, journal = {Transducers '07 Eurosensors XXI : digest of technical papers ; the14th International Conference on Solid-State Sensors, Actuators and Microsystems, June 10-14, 2007, Lyon, France / Gilles Delapierre (Ed.)}, publisher = {IEEE}, address = {Piscataway}, isbn = {1-4244-0841-5}, pages = {1891 -- 1894}, year = {2007}, language = {en} }