TY  - JOUR
A1  - Dachwald, Bernd
T1  - Optimization of very-low-thrust trajectories using evolutionary neurocontrol
JF  - Acta Astronautica
N2  - Searching optimal interplanetary trajectories for low-thrust spacecraft is usually a difficult and time-consuming task that involves much experience and expert knowledge in astrodynamics and optimal control theory. This is because the convergence behavior of traditional local optimizers, which are based on numerical optimal control methods, depends on an adequate initial guess, which is often hard to find, especially for very-low-thrust trajectories that necessitate many revolutions around the sun. The obtained solutions are typically close to the initial guess that is rarely close to the (unknown) global optimum. Within this paper, trajectory optimization problems are attacked from the perspective of artificial intelligence and machine learning. Inspired by natural archetypes, a smart global method for low-thrust trajectory optimization is proposed that fuses artificial neural networks and evolutionary algorithms into so-called evolutionary neurocontrollers. This novel method runs without an initial guess and does not require the attendance of an expert in astrodynamics and optimal control theory. This paper details how evolutionary neurocontrol works and how it could be implemented. The performance of the method is assessed for three different interplanetary missions with a thrust to mass ratio <0.15mN/kg (solar sail and nuclear electric).
Y1  - 2005
SN  - 1879-2030
VL  - 57
IS  - 2-8
SP  - 175
EP  - 185
PB  - Elsevier
CY  - Amsterdam [u.a.]
ER  - 
TY  - JOUR
A1  - Staat, Manfred
T1  - Direct finite element route for design-by-analysis of pressure components
N2  - In the new European standard for unfired pressure vessels, EN 13445-3, there are two approaches for carrying out a Design-by-Analysis that cover both the stress categorization method (Annex C) and the direct route method (Annex B) for a check against global plastic deformation and against progressive plastic deformation. This paper presents the direct route in the language of limit and shakedown analysis. This approach leads to an optimization problem. Its solution with Finite Element Analysis is demonstrated for mechanical and thermal actions. One observation from the examples is that the so-called 3f (3Sm) criterion fails to be a reliable check against progressive plastic deformation. Precise conditions are given, which greatly restrict the applicability of the 3f criterion.
KW  - Einspielen <Werkstoff>
KW  - Plastizität
KW  - Deformation
KW  - Analytischer Zulaessigkeitsnachweis
KW  - Einspiel-Analyse
KW  - fortschreitende plastische Deformation
KW  - alternierend Verformbarkeit
KW  - Einspiel-Kriterium
KW  - Design-by-analysis
KW  - Shakedown analysis
KW  - Progressive plastic deformation
KW  - Alternating plasticity
KW  - Shakedown criterion
Y1  - 2005
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Turyshev, Slava G.
A1  - Dittus, H.
A1  - Shao, M. [u.a.]
T1  - Fundamental Physics with the Laser Astrometric Test Of Relativity / S.G. Turyshev ;  H. Dittus ; M. Shao ... B.Dachwald ...
JF  - Proceedings of the 39th ESLAB Symposium "Trends in Space Science and Cosmic Vision 2020" : 19 - 21 April 2005, ESTEC, Noordwijk, the Netherlands / European Space Agency. [Comp. by: F. Favata ...] . - (ESA SP ; 588)
Y1  - 2005
SN  - 9290928999
N1  - ISBN der CD-ROM-Ausg.: 9290928999 ; Symposium Trends in Space Science and Cosmic Vision 2020 <2005, Noordwijk> ; ESLAB symposium <39, 2005, Noordwijk> ; European Space Laboratory
SP  - 8
EP  - 11
PB  - ESA Publ. Div.
CY  - Noordwijk
ER  - 
TY  - JOUR
A1  - Dittus, H.
A1  - Turyshev, S. G.
A1  - Dachwald, Bernd
A1  - Blome, Hans-Joachim
T1  - A Mission to Explore the Pioneer Anomaly
JF  - Proceedings of the 39th ESLAB Symposium "Trends in Space Science and Cosmic Vision 2020" : 19 - 21 April 2005, ESTEC, Noordwijk, the Netherlands / European Space Agency. [Comp. by: F. Favata ...] . - (ESA SP ; 588)
Y1  - 2005
SN  - 9290928999
N1  - ISBN der CD-ROM-Ausg.: 9290928999 ; Symposium Trends in Space Science and Cosmic Vision 2020 <2005, Noordwijk> ; ESLAB symposium <39,2005, Noordwijk> ; European Space Laboratory ; Report Number: LA-UR-05-4907 ; The Pioneer Explorer Collaboration
SP  - 3
EP  - 10
PB  - ESA Publ. Div.
CY  - Noordwijk
ER  - 
TY  - JOUR
A1  - Dachwald, Bernd
A1  - Seboldt, Wolfgang
T1  - Solar Sails for Near- and Medium-Term Scientific Deep Space Missions / W. Sebolt ; B. Dachwald
JF  - In-space propulsion : edited book of proceedings of the 10-IWCP, the 10th International Workshop on Combustion and Propulsion held in Lerici, La Spezia, Italy, 21-25 September 2003 / [ed.: Luigi T. DeLuca]
Y1  - 2005
N1  - Paper 31 ; International workshop on combustion and propulsion <10, 2003, Lerici>
PB  - SP Lab, Politecnico di Milano
CY  - Milano
ER  - 
TY  - JOUR
A1  - Ferrein, Alexander
A1  - Jacobs, Stefan
A1  - Lakemeyer, Gerhard
T1  - Controlling Unreal Tournament 2004 Bots with the logic-based action language Golog / Jacobs, Stefan ; Ferrein, Alexander ; Lakemeyer, Gerhard
JF  - Proceedings of the First AAAI Conference on Artificial Intelligence and Interactive Digital Entertainment (AIIDE).
Y1  - 2005
SP  - 151
EP  - 152
ER  - 
TY  - CHAP
A1  - Bitz, Andreas
A1  - El Ouardi, A.
A1  - Streckert, J.
A1  - Hansen, V.
T1  - Efficient calculation of human exposure in front of base station antennas by a combination of the FDTD and Hybrid(2)-method
T2  - Proceedings of the 16th International Zurich Symposium on Electromagnetic Compatibility, Topical Meeting on Biomedical EMC, Zurich, Switzerland, February 2005
Y1  - 2005
SN  - 3-9521199-9-7
SP  - 115
EP  - 118
PB  - ETH Zentrum
CY  - Zürich
ER  - 
TY  - JOUR
A1  - Franke, Helmut
A1  - Streckert, Joachim
A1  - Bitz, Andreas
A1  - Goeke, Johannes
A1  - Hansen, Volkert
A1  - Ringelstein, E. Bernd
A1  - Nattkämper, Heiner
A1  - Galle, Hans-Joachim
A1  - Stögbauer, Florian
T1  - Effects of Universal Mobile Telecommunications System (UMTS) electromagnetic fields on the blood-brain barrier in vitro
JF  - Radiation Research
Y1  - 2005
U6  - https://doi.org/10.1667/RR3424.1
SN  - 1938-5404
VL  - 164
IS  - 3
SP  - 258
EP  - 269
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  - JOUR
A1  - Braband, Henrik
A1  - Yegen, Eda
A1  - Paulßen, Elisabeth
A1  - Abram, Ulrich
T1  - [{ReN(PMe2Ph)3}{ReO3N}]2 – Structural Evidence for the Nitridotrioxorhenate(VII) Anion, [ReO3N]2−
JF  - Zeitschrift für anorganische und allgemeine Chemie : ZAAC = Journal of inorganic and general chemistry
Y1  - 2005
U6  - https://doi.org/10.1002/zaac.200500240
SN  - 1521-3749
VL  - 631
IS  - 12
SP  - 2408
EP  - 2410
ER  -