@article{ThielemannKriegesmannSchaffner1995, author = {Thielemann, Frank and Kriegesmann, Bernd and Schaffner, M.}, title = {Mit vereinten Kr{\"a}ften die Wettbewerbsf{\"a}higkeit steigern - Kooperation als Antwort auf den In­novationsdruck . Kriegesmann, B.; Thielemann, F.; Schaffner, M.}, series = {Der Druckspiegel. 50 (1995), H. 10}, journal = {Der Druckspiegel. 50 (1995), H. 10}, isbn = {0012-6500}, pages = {931 -- 935}, year = {1995}, language = {de} } @article{FoersterZamdmerHuetal.1999, author = {F{\"o}rster, Arnold and Zamdmer, N. and Hu, Qing and Verghese, S.}, title = {Mode-Discriminating Photoconductor and Coplanar Wave-Guide Circuits for Picosecond Sampling. Zamdmer, N.; Hu, Qing ; Verghese, S. ; F{\"o}rster, A.}, series = {Applied Physics Letters. 74 (1999), H. 7}, journal = {Applied Physics Letters. 74 (1999), H. 7}, isbn = {1077-3118}, pages = {1039 -- 1041}, year = {1999}, language = {en} } @inproceedings{SchwagerAngeleSchwarzboezletal.2023, author = {Schwager, Christian and Angele, Florian and Schwarzb{\"o}zl, Peter and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf}, title = {Model predictive assistance for operational decision making in molten salt receiver systems}, series = {SolarPACES: Solar Power \& Chemical Energy Systems}, booktitle = {SolarPACES: Solar Power \& Chemical Energy Systems}, number = {2815 / 1}, publisher = {AIP conference proceedings / American Institute of Physics}, address = {Melville, NY}, isbn = {978-0-7354-4623-6}, issn = {1551-7616 (online)}, doi = {10.1063/5.0151514}, pages = {8 Seiten}, year = {2023}, abstract = {Despite the challenges of pioneering molten salt towers (MST), it remains the leading technology in central receiver power plants today, thanks to cost effective storage integration and high cost reduction potential. The limited controllability in volatile solar conditions can cause significant losses, which are difficult to estimate without comprehensive modeling [1]. This paper presents a Methodology to generate predictions of the dynamic behavior of the receiver system as part of an operating assistance system (OAS). Based on this, it delivers proposals if and when to drain and refill the receiver during a cloudy period in order maximize the net yield and quantifies the amount of net electricity gained by this. After prior analysis with a detailed dynamic two-phase model of the entire receiver system, two different reduced modeling approaches where developed and implemented in the OAS. A tailored decision algorithm utilizes both models to deliver the desired predictions efficiently and with appropriate accuracy.}, language = {en} } @article{RiekeStollenwerkDahmenetal.2018, author = {Rieke, Christian and Stollenwerk, Dominik and Dahmen, Markus and Pieper, Martin}, title = {Modeling and optimization of a biogas plant for a demand-driven energy supply}, series = {Energy}, volume = {145}, journal = {Energy}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0360-5442}, doi = {10.1016/j.energy.2017.12.073}, pages = {657 -- 664}, year = {2018}, abstract = {Due to the Renewable Energy Act, in Germany it is planned to increase the amount of renewable energy carriers up to 60\%. One of the main problems is the fluctuating supply of wind and solar energy. Here biogas plants provide a solution, because a demand-driven supply is possible. Before running such a plant, it is necessary to simulate and optimize the process. This paper provides a new model of a biogas plant, which is as accurate as the standard ADM1 model. The advantage compared to ADM1 is that it is based on only four parameters compared to 28. Applying this model, an optimization was installed, which allows a demand-driven supply by biogas plants. Finally the results are confirmed by several experiments and measurements with a real test plant.}, language = {en} } @inproceedings{RendonSchwagerGhiasietal.2020, author = {Rendon, Carlos and Schwager, Christian and Ghiasi, Mona and Schmitz, Pascal and Bohang, Fakhri and Caminos, Ricardo Alexander Chico and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf}, title = {Modeling and upscaling of a pilot bayonettube reactor for indirect solar mixed methane reforming}, series = {AIP Conference Proceedings}, booktitle = {AIP Conference Proceedings}, number = {2303}, doi = {10.1063/5.0029974}, pages = {170012-1 -- 170012-9}, year = {2020}, language = {en} } @article{VogtIwanowskiStrahserMarquartetal.2013, author = {Vogt, Christian and Iwanowski-Strahser, Katha and Marquart, Gabriele and Arnold, Juliane and Mottaghy, Darius and Pechnig, Renate and Gnjezda, Daniel and Clauser, Christoph}, title = {Modeling contribution to risk assessment of thermal production power for geothermal reservoirs}, series = {Renewable Energy}, volume = {53}, journal = {Renewable Energy}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0960-1481}, doi = {10.1016/j.renene.2012.11.026}, pages = {230 -- 241}, year = {2013}, language = {en} } @inproceedings{ZahraPhaniSrujanCaminosetal.2022, author = {Zahra, Mahdi and Phani Srujan, Merige and Caminos, Ricardo Alexander Chico and Schmitz, Pascal and Herrmann, Ulf and Teixeira Boura, Cristiano Jos{\´e} and Schmitz, Mark and Gielen, Hans and Gedle, Yibekal and Dersch, J{\"u}rgen}, title = {Modeling the thermal behavior of solar salt in electrical resistance heaters for the application in PV-CSP hybrid power plants}, series = {SOLARPACES 2020}, booktitle = {SOLARPACES 2020}, number = {2445 / 1}, publisher = {AIP conference proceedings / American Institute of Physics}, address = {Melville, NY}, isbn = {978-0-7354-4195-8}, issn = {1551-7616 (online)}, doi = {10.1063/5.0086268}, pages = {9 Seiten}, year = {2022}, abstract = {Concentrated Solar Power (CSP) systems are able to store energy cost-effectively in their integrated thermal energy storage (TES). By intelligently combining Photovoltaics (PV) systems with CSP, a further cost reduction of solar power plants is expected, as well as an increase in dispatchability and flexibility of power generation. PV-powered Resistance Heaters (RH) can be deployed to raise the temperature of the molten salt hot storage from 385 °C up to 565 °C in a Parabolic Trough Collector (PTC) plant. To avoid freezing and decomposition of molten salt, the temperature distribution in the electrical resistance heater is investigated in the present study. For this purpose, a RH has been modeled and CFD simulations have been performed. The simulation results show that the hottest regions occur on the electric rod surface behind the last baffle. A technical optimization was performed by adjusting three parameters: Shell-baffle clearance, electric rod-baffle clearance and number of baffles. After the technical optimization was carried out, the temperature difference between the maximum temperature and the average outlet temperature of the salt is within the acceptable limits, thus critical salt decomposition has been avoided. Additionally, the CFD simulations results were analyzed and compared with results obtained with a one-dimensional model in Modelica.}, language = {en} } @book{MeissenHotfilter1972, author = {Meißen, Ralf and Hotfilter, Josef}, title = {Modell einer Einrichtung zur Positionierung von kugelf{\"o}rmigen Brennelementen nach einer Bohrung mit ber{\"u}hrungsloser fluidischer Abtastung / Josef Hotfilter ; Ralf Meißen}, publisher = {Kernforschungsanlage}, address = {J{\"u}lich}, pages = {17 Bl.: graph. Darst.}, year = {1972}, language = {de} } @inproceedings{RosinKubalskiButenweg2013, author = {Rosin, Julia and Kubalski, Thomas and Butenweg, Christoph}, title = {Modellierung eines basisisolierten, zylindrischen Fl{\"u}ssigkeitstanks aus Stahl}, series = {13. D-A-CH Tagung f{\"u}r Erdbebeningenieurwesen und Baudynamik (D-A-CH 2013) : 29.-30. August 2013, Wien, {\"O}sterreich}, booktitle = {13. D-A-CH Tagung f{\"u}r Erdbebeningenieurwesen und Baudynamik (D-A-CH 2013) : 29.-30. August 2013, Wien, {\"O}sterreich}, organization = {D-A-CH Tagung f{\"u}r Erdbebeningenieurwesen und Baudynamik <13, 2013, Wien>}, pages = {1 -- 10}, year = {2013}, language = {de} } @article{KubalskiButenweg2015, author = {Kubalski, Thomas and Butenweg, Christoph}, title = {Modelling strategies for horizontally loaded infill masonry}, series = {Mauerwerk : European journal of masonry}, volume = {Volume 19}, journal = {Mauerwerk : European journal of masonry}, number = {Issue 5}, publisher = {Wiley}, address = {Weinheim}, doi = {10.1002/dama.201500675}, pages = {363 -- 369}, year = {2015}, language = {de} } @inproceedings{MertensBraunerBaieretal.2022, author = {Mertens, Alexander and Brauner, Philipp and Baier, Ralph and Brillowski, Florian and Dammers, Hannah and van Dyck, Marc and Kong, Iris and K{\"o}nigs, Peter and Kordtomeikel, Frauke and Liehner, Gian Luca and P{\"u}tz, Sebastian and Rodermann, Niklas and Schaar, Anne Kathrin and Steuer-Dankert, Linda and Vervier, Luisa and Wlecke, Shari and Gries, Thomas and Leicht-Scholten, Carmen and Nagel, Saskia K. and Piller, Frank T. and Schuh, G{\"u}nther and Ziefle, Martina and Nitsch, Verena}, title = {Modelling Human Factors in Cyber Physical Production Systems by the Integration of Human Digital Shadows}, series = {Modellierung 2022 Satellite Events}, booktitle = {Modellierung 2022 Satellite Events}, editor = {Michael, Judith and Pfeiffer, J{\´e}r{\^o}me and Wortmann, Andreas}, publisher = {GI Gesellschaft f{\"u}r Informatik}, address = {Bonn}, doi = {10.18420/modellierung2022ws-018}, pages = {147 -- 149}, year = {2022}, abstract = {The future of industrial manufacturing and production will increasingly manifest in the form of cyber-physical production systems. Here, Digital Shadows will act as mediators between the physical and digital world to model and operationalize the interactions and relationships between different entities in production systems. Until now, the associated concepts have been primarily pursued and implemented from a technocentric perspective, in which human actors play a subordinate role, if they are considered at all. This paper outlines an anthropocentric approach that explicitly considers the characteristics, behavior, and traits and states of human actors in socio-technical production systems. For this purpose, we discuss the potentials and the expected challenges and threats of creating and using Human Digital Shadows in production.}, language = {en} } @article{MistlerButenwegMeskouris2006, author = {Mistler, Michael and Butenweg, Christoph and Meskouris, Konstantin}, title = {Modelling methods of historic masonry buildings under seismic excitation}, series = {Journal of seismology}, volume = {Volume 10}, journal = {Journal of seismology}, number = {No. 4}, issn = {1383-4649 (Print) ; 1573-157X (E-Journal)}, doi = {10.1007/s10950-006-9033-z}, pages = {497 -- 510}, year = {2006}, language = {en} } @inproceedings{KalkerNeumannButenwegetal.2005, author = {Kalker, Ines and Neumann, M. and Butenweg, Christoph and Holler, Stefan}, title = {Modelling of textile strengthened masonry}, series = {Proceedings of the Tenth International Conference on Civil, Structural and Environmental Engineering Computing : [Rome, Italy, 30. August - 2. September 2005] / ed. by B. H. V. Topping}, booktitle = {Proceedings of the Tenth International Conference on Civil, Structural and Environmental Engineering Computing : [Rome, Italy, 30. August - 2. September 2005] / ed. by B. H. V. Topping}, publisher = {Civil-Comp Press}, address = {Stirling}, organization = {International Conference on Civil, Structural and Environmental Engineering Computing <10, 2005, Rome>}, isbn = {1-905088-00-0}, doi = {10.4203/ccp.81.184}, pages = {447 -- 448}, year = {2005}, language = {en} } @article{FoersterZettlerMikkelsenetal.1992, author = {F{\"o}rster, Arnold and Zettler, J.-T. and Mikkelsen, H. and Leo, K.}, title = {Modulated ellipsometric measurements and transfer-matrix calculation of the field-dependent dielectric function of a multiple quantum well / J.-Th. Zettler ; H. Mikkelsen ; K. Leo ... A. F{\"o}rster}, series = {Physical Review B . 46 (1992), H. 24}, journal = {Physical Review B . 46 (1992), H. 24}, isbn = {0163-1829}, pages = {15955 -- 15962}, year = {1992}, language = {en} } @inproceedings{KueppersGroebelKuperjansetal.2011, author = {K{\"u}ppers, Christine and Groebel, Simone and Kuperjans, Isabel and Dielmann, Klaus-Peter}, title = {Molekulargenetische Analysen zur Optimierung der Biogasgewinnung}, series = {Biogas 2011 : 4. Innovationskongress ; Effizienzsteigerung von Biogasanlagen ; Vorstellung der 17 besten Biogas-Innovationen der letzten 12 Monate ; 12. - 13. Mai 2011, im ZUK der Deutschen Bundesstiftung Umwelt ; Tagungsband}, booktitle = {Biogas 2011 : 4. Innovationskongress ; Effizienzsteigerung von Biogasanlagen ; Vorstellung der 17 besten Biogas-Innovationen der letzten 12 Monate ; 12. - 13. Mai 2011, im ZUK der Deutschen Bundesstiftung Umwelt ; Tagungsband}, publisher = {Profair Consult+Project}, address = {Hildesheim}, isbn = {978-3-9813776-1-3}, pages = {45 -- 48}, year = {2011}, language = {de} } @article{RossiWinandsButenweg2022, author = {Rossi, Leonardo and Winands, Mark H. M. and Butenweg, Christoph}, title = {Monte Carlo Tree Search as an intelligent search tool in structural design problems}, series = {Engineering with Computers : An International Journal for Simulation-Based Engineering}, volume = {38}, journal = {Engineering with Computers : An International Journal for Simulation-Based Engineering}, number = {4}, editor = {Zhang, Jessica}, publisher = {Springer Nature}, address = {Cham}, issn = {1435-5663}, doi = {10.1007/s00366-021-01338-2}, pages = {3219 -- 3236}, year = {2022}, abstract = {Monte Carlo Tree Search (MCTS) is a search technique that in the last decade emerged as a major breakthrough for Artificial Intelligence applications regarding board- and video-games. In 2016, AlphaGo, an MCTS-based software agent, outperformed the human world champion of the board game Go. This game was for long considered almost infeasible for machines, due to its immense search space and the need for a long-term strategy. Since this historical success, MCTS is considered as an effective new approach for many other scientific and technical problems. Interestingly, civil structural engineering, as a discipline, offers many tasks whose solution may benefit from intelligent search and in particular from adopting MCTS as a search tool. In this work, we show how MCTS can be adapted to search for suitable solutions of a structural engineering design problem. The problem consists of choosing the load-bearing elements in a reference reinforced concrete structure, so to achieve a set of specific dynamic characteristics. In the paper, we report the results obtained by applying both a plain and a hybrid version of single-agent MCTS. The hybrid approach consists of an integration of both MCTS and classic Genetic Algorithm (GA), the latter also serving as a term of comparison for the results. The study's outcomes may open new perspectives for the adoption of MCTS as a design tool for civil engineers.}, language = {en} } @article{FoersterTillmannGerthsen1995, author = {F{\"o}rster, Arnold and Tillmann, K. and Gerthsen, D.}, title = {Morphological transformations of MBE-grown In0.6Ga0.4As island on GaAs(001) substrates / K. Tillmann ; D. Gerthsen ; P. Pfundstein ; A. F{\"o}rster ...}, series = {Microscopy of semiconducting materials 1995 : proceedings of the Institute of Physics Conference held at Oxford University, 20 - 23 March 1995 / Ed. by A G Cullis ... - (Conference series / Institute of Physics ; 146)}, journal = {Microscopy of semiconducting materials 1995 : proceedings of the Institute of Physics Conference held at Oxford University, 20 - 23 March 1995 / Ed. by A G Cullis ... - (Conference series / Institute of Physics ; 146)}, publisher = {Institute of Physics}, address = {Bristol [u.a.]}, isbn = {0-7503-0347-6}, pages = {195 -- ff.}, year = {1995}, language = {en} } @inproceedings{RajanKubalskiAltayetal.2017, author = {Rajan, Sreelakshmy and Kubalski, Thomas and Altay, Okyay and Dalguer, Luis A and Butenweg, Christoph}, title = {Multi-dimensional fragility analysis of a RC building with components using response surface method}, series = {24th International Conference on Structural Mechanics in Reactor Technology, Busan, Korea, 20-25 August, 2017}, booktitle = {24th International Conference on Structural Mechanics in Reactor Technology, Busan, Korea, 20-25 August, 2017}, publisher = {International Assn for Structural Mechanics in Reactor Technology (IASMiRT)}, address = {Raleigh, USA}, isbn = {9781510856776}, pages = {3126 -- 3135}, year = {2017}, abstract = {Conventional fragility curves describe the vulnerability of the main structure under external hazards. However, in complex structures such as nuclear power plants, the safety or the risk depends also on the components associated with a system. The classical fault tree analysis gives an overall view of the failure and contains several subsystems to the main event, however, the interactions in the subsystems are not well represented. In order to represent the interaction of the components, a method suggested by Cimellaro et al. (2006) using multidimensional performance limit state functions to obtain the system fragility curves is adopted. This approach gives the possibility of deriving the cumulative fragility taking into account the interaction of the response of different components. In this paper, this approach is used to evaluate seismic risk of a representative electrical building infrastructure, including the component, of a nuclear power plant. A simplified model of the structure, with nonlinear material behavior is employed for the analysis in Abaqus©. The input variables considered are the material parameters, boundary conditions and the seismic input. The variability of the seismic input is obtained from selected ground motion time histories of spectrum compatible synthetic ccelerograms. Unlike the usual Monte Carlo methods used for the probabilistic analysis of the structure, a computationally effective response surface method is used. This method reduces the computational effort of the calculations by reducing the required number of samples.}, language = {en} } @article{GoettscheAlexopoulosDuemmleretal.2019, author = {G{\"o}ttsche, Joachim and Alexopoulos, Spiros and D{\"u}mmler, Andreas and Maddineni, S. K.}, title = {Multi-Mirror Array Calculations With Optical Error}, pages = {1 -- 6}, year = {2019}, abstract = {The optical performance of a 2-axis solar concentrator was simulated with the COMSOL Multiphysics® software. The concentrator consists of a mirror array, which was created using the application builder. The mirror facets are preconfigured to form a focal point. During tracking all mirrors are moved simultaneously in a coupled mode by 2 motors in two axes, in order to keep the system in focus with the moving sun. Optical errors on each reflecting surface were implemented in combination with the solar angular cone of ± 4.65 mrad. As a result, the intercept factor of solar radiation that is available to the receiver was calculated as a function of the transversal and longitudinal angles of incidence. In addition, the intensity distribution on the receiver plane was calculated as a function of the incidence angles.}, language = {en} } @inproceedings{FeldhusenBrezingPuetzetal.2010, author = {Feldhusen, J{\"o}rg and Brezing, Alexander Nikolaus and P{\"u}tz, Claus and W{\"a}hlisch, Georg}, title = {Multi-system CAD-teaching in large classes}, series = {When design education and design research meet : proceedings of the 12th International Conference on Engineering and Product Design Education, Norwegian University of Science and Technology (NTNU) Trondheim, Norway, 2nd - 3rd September 2010 ; [E\&PDE]}, booktitle = {When design education and design research meet : proceedings of the 12th International Conference on Engineering and Product Design Education, Norwegian University of Science and Technology (NTNU) Trondheim, Norway, 2nd - 3rd September 2010 ; [E\&PDE]}, publisher = {Design Society}, address = {Glasgow}, organization = {International Conference on Engineering and Product Design Education <12, 2010, Trondheim>}, isbn = {978-1-904670-19-3}, pages = {204 -- 209}, year = {2010}, language = {en} }