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  - Sommer, Angela M.
A1  - Bitz, Andreas
A1  - Streckert, Joachim
A1  - Hansen, Volkert W.
A1  - Lerchl, Alexander
T1  - Lymphoma development in mice chronically exposed to UMTS-modulated radiofrequency electromagnetic fields
JF  - Radiation Research
Y1  - 2007
U6  - http://dx.doi.org/10.1667/RR0857.1
SN  - 1938-5404
VL  - 168
IS  - 1
SP  - 72
EP  - 80
ER  - 
TY  - JOUR
A1  - Hartung, Frank
A1  - Kampmann, Markus
T1  - Media Delivery Based on Service Aware Transport Overlay Networks  / Kampmann, Markus ; Hartung, Frank
JF  - KIVS 2007 : Kommunikation in verteilten Systemen : 15. ITG-GI-Fachtagung vom 26. Februar bis 2. März 2007 in Bern, Schweiz ; Industriebeiträge, Kurzbeiträge und Workshops / T. Braun ... (Hrsg.)
Y1  - 2007
SN  - 978-3-8007-2980-7
N1  - Communication in Distributed Systems (KiVS), 2007 ITG-GI Conference
SP  - 9
EP  - 10
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  - http://dx.doi.org/10.1109/TMTT.2007.902587
VL  - 55
IS  - 8
SP  - 1704
EP  - 1708
PB  - IEEE
CY  - New York
ER  - 
TY  - CHAP
A1  - Buda, Aurel
A1  - Jozenfini, B.
A1  - Wollert, Jörg
T1  - Mobile ad-hoc Network for home automation based on ZigBee application framework
T2  - 1st European ZigBee Developer's Conference : June 18 - 20, 2007, Munich, Germany
Y1  - 2007
SP  - 1
EP  - 5
PB  - Design & Elektronik
CY  - Poing
ER  - 
TY  - JOUR
A1  - Hartung, Frank
A1  - Kampmann, Markus
A1  - Horn, Uwe
A1  - Kritzner, Jan
T1  - Mobile Television / Hartung, Frank ; Kampmann, Markus ; Horn, Uwe ; Kritzner, Jan
JF  - Encyclopedia of mobile computing and commerce / David Taniar ; Bd. 2 : Mobile ICT - Z
Y1  - 2007
SN  - 978-1-59904-002-8
SP  - 611
EP  - 615
PB  - Information Science Reference
CY  - Hershey
ER  - 
TY  - JOUR
A1  - Hartung, Frank
A1  - Horn, Uwe
A1  - Huschke, Jörg
A1  - Kampmann, Markus
T1  - Mobile TV Services in 3G Networks / Hartung, Frank ; Horn, Uwe ; Huschke, Jörg ; Kampmann, Markus ; Lohmar, Thorsten
JF  - KIVS 2007 : Kommunikation in verteilten Systemen : 15. ITG-GI-Fachtagung vom 26. Februar bis 2. März 2007 in Bern, Schweiz ; Industriebeiträge, Kurzbeiträge und Workshops / T. Braun ... (Hrsg.)
Y1  - 2007
SN  - 978-3-8007-2980-7
N1  - Communication in Distributed Systems (KiVS), 2007 ITG-GI Conference
SP  - 15
EP  - 18
ER  - 
TY  - CHAP
A1  - Pfaff, Raphael
A1  - Pichler, Alexander
A1  - George, Alfred
A1  - Seiler, Friedrich
T1  - Model based image processing for flow visualisation : 16th International Conference on Systems Science, Wroclaw, Poland, September 04 - 06, 2007
T2  - PU / Institut Franco-Allemand de Recherches de Saint-Louis ; 2007, 620
Y1  - 2007
SP  - 1
EP  - 10
PB  - ISL
CY  - Saint Louis, France
ER  - 
TY  - CHAP
A1  - Kirsch, Ansgar
A1  - Blioumi, A.
A1  - Fellin, Wolfgang
A1  - Kolymbas, Dimitrios
T1  - Modelling anisotropic squeezing as a process in time
T2  - ECCOMAS Thematic Conference on Computational Methods in Tunneling ; August 27 - 29, 2007, Vienna, Austria : EURO:TUN 2007 : proceedings
Y1  - 2007
SN  - 3-9501554-7-3 ; 978-3-9501554-7-1
CY  - Wien
ER  - 
TY  - CHAP
A1  - Weßling, Matthias
T1  - Motivation and Leadership - The Reiss-Profile of the 16 Basic Desires: Research results and managerial applications
N2  - Recent Results of the scientific Reiss-Profile (16 basic desires) due to the concept of Prof. Dr. Steven Reiss (State University Ohio, U.S.A.), supplemented by the comparative analysis of empirical motivational profiles of european executives of various companies.
N2  - Neuere Forschungsergebnisse des wissenschaftlichen Reiss-Profils der 16 Lebensmotive nach Prof. Dr. Steven Reiss (State University Ohio, U.S.A.) und die Möglichkeiten und Grenzen ihrer Umsetzung in der betrieblichen Führungspraxis unter Integration der vergleichenden Analyse und Interpretation empirisch erhobener Motivprofile einzelner europäischer Führungskräfte.
KW  - Motivation
KW  - Leadership
KW  - Motivation
KW  - Führung
KW  - Motivation
KW  - Leadership
Y1  - 2007
ER  - 
TY  - CHAP
A1  - Müller-Veggian, Mattea
A1  - Kops, Elena Rota
A1  - Quin, Peng
A1  - Herzog, Hans
T1  - MRI Based Attenuation Correction for Brain PET Images
T2  - Advances in medical engineering / [3rd RPT - Remagener Physiktage together with the Second Scientific Workshop of Medical Robotics, Navigation and Visualization ... Remagen ... 7.-9. März 2007]. Thorsten M. Buzug (ed.) Part 1.
N2  - This work describes a procedure to yield attenuation maps from MR images which are used for the absorption correction (AC) of brain PET data. Such an approach could be mandatory for future combined PET and MRI scanners, which probably do not include a transmission facility. T1-weighted MR images were segmented into brain tissue, bone, soft tissue, and sinus; attenuation coefficients corresponding to elemental composition and density as well as to 511 keV photon energy were respectively assigned. Attenuation maps containing up to four compartments were created and forward projected into sinograms with attenuation factors which then were used for AC during reconstruction of FDG-PET data. The commonly used AC based on a radioactive (68Ge) transmission scan served as reference. The reconstructed radioactivity values obtained with the MRI-based AC were about 20% lower than those obtained with PET-based AC if the skull was not taken into account. Considering the skull the difference was still about 10%. Our investigations demonstrate the feasibility of a MRI-based AC, but revealed also the necessity of a satisfying delineation of bone thickness which tends to be underestimated in our first approach of T1-weighted MR image segmentation.
Y1  - 2007
SN  - 978-3-540-68763-4
U6  - http://dx.doi.org/10.1007/978-3-540-68764-1_15
N1  - Springer proceedings in physics ; 114
SP  - 93
EP  - 97
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Hartung, Frank
A1  - Dondeti, L.
A1  - Castleford, F.
T1  - Multimedia Internet KEYing (MIKEY) General Extension Payload for Open Mobile Alliance BCAST LTKM/STKM Transport / Dondeti, L. ; Castleford, D. ; Hartung, F.
Y1  - 2007
SP  - 1
EP  - 7
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  - JOUR
A1  - Christiaens, P.
A1  - Abouzar, Maryam H.
A1  - Poghossian, Arshak
A1  - Wagner, Torsten
A1  - Bijnens, N.
A1  - Williams, O. A.
A1  - Daenen, M.
A1  - Haenen, K.
A1  - Schöning, Michael Josef
A1  - Wagner, P.
T1  - Nanocrystalline diamond-based field-effect capacitive pH sensor
JF  - 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.)
Y1  - 2007
SN  - 1-4244-0841-5
N1  - Eurosensors 21, 2007, Lyon ; International Conference on Solid-State Sensors, Actuators and Microsystems 14, 2007, Lyon
SP  - 1891
EP  - 1894
PB  - IEEE
CY  - Piscataway
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  - CHAP
A1  - Meskouris, Konstantin
A1  - Butenweg, Christoph
A1  - Kalker, Ines
A1  - Mistler, Michael
T1  - Numerical simulation of historic masonry buildings
T2  - Antike Erdbeben im alpinen und zirkumalpinen Raum : Befunde und Probleme in archäologischer, historischer und seismologischer Sicht ; Beiträge des Interdisziplinären 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)
Y1  - 2007
SN  - 978-3-515-09030-8 ; 3-515-09030-4
SP  - 171
EP  - 189
PB  - Franz Steiner Verlag
CY  - Stuttgart
ER  - 
TY  - JOUR
A1  - Dankelmann, Peter
A1  - Hellwig, Angelika
A1  - Volkmann, Lutz
T1  - On the connectivity of diamond-free graphs
JF  - Discrete applied mathematics
Y1  - 2007
SN  - 0166-218X (E-Journal); 1872-6771 (E-Journal); 0166-218X (Print)
VL  - Vol. 155
IS  - Iss. 16
SP  - 2111
EP  - 2117
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  - CHAP
A1  - Dachwald, Bernd
A1  - Mengali, Giovanni
A1  - Quarta, Alessandro A
A1  - Macdonald, Malcolm
A1  - McInnes, Colin R
T1  - Optical solar sail degradation modelling
T2  - 1st International Symposium on Solar Sailing
N2  - 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.
Y1  - 2007
N1  - 1st International Symposium on Solar Sailing 27–29 June 2007, Herrsching, Germany
SP  - 1
EP  - 27
ER  - 
TY  - CHAP
A1  - Tippkötter, Nils
A1  - Stückmann, H.
A1  - Winkelmann, G.
A1  - Noack, U.
A1  - Beutel, S.
A1  - Scheper, T.
A1  - Ulber, R.
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  -