@inproceedings{MilkovaRosinButenwegetal.2018, author = {Milkova, Kristina and Rosin, Julia and Butenweg, Christoph and Dumova-Jovanoska, Elena}, title = {Development of Seismic Vulnerability Curves for Region Specific Masonry Buildings}, series = {16th European Conference on Earthquake Engineering, Thessaloniki, 18-21 June, 2018}, booktitle = {16th European Conference on Earthquake Engineering, Thessaloniki, 18-21 June, 2018}, pages = {1 -- 10}, year = {2018}, language = {en} } @inproceedings{SchmittRosinButenweg2018, author = {Schmitt, Timo and Rosin, Julia and Butenweg, Christoph}, title = {Seismic Impact And Design Of Buried Pipelines}, series = {16th European Conference on Earthquake Engineering, Thessaloniki, 18-21 June, 2018}, booktitle = {16th European Conference on Earthquake Engineering, Thessaloniki, 18-21 June, 2018}, pages = {1 -- 12}, year = {2018}, abstract = {Seismic design of buried pipeline systems for energy and water supply is not only important for plant and operational safety but also for the maintenance of the supply infrastructure after an earthquake. The present paper shows special issues of the seismic wave impacts on buried pipelines, describes calculation methods, proposes approaches and gives calculation examples. This paper regards the effects of transient displacement differences and resulting tensions within the pipeline due to the wave propagation of the earthquake. However, the presented model can also be used to calculate fault rupture induced displacements. Based on a three-dimensional Finite Element Model parameter studies are performed to show the influence of several parameters such as incoming wave angle, wave velocity, backfill height and synthetic displacement time histories. The interaction between the pipeline and the surrounding soil is modeled with non-linear soil springs and the propagating wave is simulated affecting the pipeline punctually, independently in time and space. Special attention is given to long-distance heat pipeline systems. Here, in regular distances expansion bends are arranged to ensure movements of the pipeline due to high temperature. Such expansion bends are usually designed with small bending radii, which during the earthquake lead to high bending stresses in the cross-section of the pipeline. Finally, an interpretation of the results and recommendations are given for the most critical parameters.}, language = {en} } @inproceedings{MichelButenwegKlinkel2018, author = {Michel, Philipp and Butenweg, Christoph and Klinkel, Sven}, title = {Frequency Dependent Impedance Analysis of the Foundation-Soil-Systems of Onshore Wind Turbines}, series = {16th European Conference on Earthquake Engineering, Thessaloniki, 18-21 June, 2018}, booktitle = {16th European Conference on Earthquake Engineering, Thessaloniki, 18-21 June, 2018}, pages = {1 -- 13}, year = {2018}, language = {en} } @inproceedings{ButenwegMarinkovicFehlingetal.2018, author = {Butenweg, Christoph and Marinkovic, Marko and Fehling, Ekkehard and Pfetzing, Thomas and Kubalski, Thomas}, title = {Experimental and Numerical Investigations of Reinforced Concrete Frames with Masonry Infills under Combined In- and Out-of-plane Seismic Loading}, series = {16th European Conference on Earthquake Engineering, Thessaloniki, 18-21 June, 2018}, booktitle = {16th European Conference on Earthquake Engineering, Thessaloniki, 18-21 June, 2018}, pages = {1 -- 12}, year = {2018}, language = {en} } @inproceedings{MarinkovicButenweg2018, author = {Marinkovic, Marko and Butenweg, Christoph}, title = {Innovative System for Earthquake Resistant Masonry Infill Walls}, series = {16th European Conference on Earthquake Engineering, Thessaloniki, 18-21 June, 2018}, booktitle = {16th European Conference on Earthquake Engineering, Thessaloniki, 18-21 June, 2018}, pages = {1 -- 12}, year = {2018}, language = {en} } @inproceedings{HoegenDonckerRuetters2020, author = {Hoegen, Anne von and Doncker, Rik W. De and R{\"u}tters, Ren{\´e}}, title = {Teaching Digital Control of Operational Amplifier Processes with a LabVIEW Interface and Embedded Hardware}, series = {The 23rd International Conference on Electrical Machines and Systems (ICEMS), Hamamatsu, Japan}, booktitle = {The 23rd International Conference on Electrical Machines and Systems (ICEMS), Hamamatsu, Japan}, doi = {10.23919/ICEMS50442.2020.9290928}, pages = {1117 -- 1122}, year = {2020}, language = {en} } @inproceedings{MarinkovicButenweg2020, author = {Marinkovic, Marko and Butenweg, Christoph}, title = {Seismic behaviour of RC frames with uncoupled masonry infills having two storeys or two bays}, series = {17th International Conference -From historical to sustainable masonry, Krakow, Poland, July 5-8, 2020}, booktitle = {17th International Conference -From historical to sustainable masonry, Krakow, Poland, July 5-8, 2020}, doi = {10.1201/9781003098508-72}, pages = {1 -- 7}, year = {2020}, language = {en} } @inproceedings{MarkinkovicButenwegPaveseetal.2020, author = {Markinkovic, Marko and Butenweg, Christoph and Pavese, A. and Lanese, I. and Hoffmeister, B. and Pinkawa, M. and Vulcu, C. and Bursi, O. and Nardin, C. and Paolacci, F. and Quinci, G. and Fragiadakis, M. and Weber, F. and Huber, P. and Renault, P. and G{\"u}ndel, M. and Dyke, S. and Ciucci, M. and Marino, A.}, title = {Investigation of the seismic behaviour of structural and nonstructural components in industrial facilities by means of shaking table tests}, series = {Seismic design of industrial facilities 2020: proceedings of the 2nd International Conference on Seismic Design of Industrial Facilities (SeDIF-Conference)}, booktitle = {Seismic design of industrial facilities 2020: proceedings of the 2nd International Conference on Seismic Design of Industrial Facilities (SeDIF-Conference)}, isbn = {978-3-86359-729-0}, pages = {159 -- 172}, year = {2020}, language = {en} } @inproceedings{CacciatoreButenweg2020, author = {Cacciatore, Pamela and Butenweg, Christoph}, title = {Seismic safety of cylindrical granular material steel silos under seismic loading}, series = {Seismic design of industrial facilities 2020: proceedings of the 2nd International Conference on Seismic Design of Industrial Facilities (SeDIF-Conference)}, booktitle = {Seismic design of industrial facilities 2020: proceedings of the 2nd International Conference on Seismic Design of Industrial Facilities (SeDIF-Conference)}, isbn = {978-3-86359-729-0}, pages = {231 -- 244}, year = {2020}, language = {en} } @inproceedings{MichelRosinButenwegetal.2020, author = {Michel, Philipp and Rosin, Julia and Butenweg, Christoph and Klinkel, Sven}, title = {Soil-dependent earthquake spectra in the analysis of liquid-storage-tanks on compliant soil}, series = {Seismic design of industrial facilities 2020: proceedings of the 2nd International Conference on Seismic Design of Industrial Facilities (SeDIF-Conference)}, booktitle = {Seismic design of industrial facilities 2020: proceedings of the 2nd International Conference on Seismic Design of Industrial Facilities (SeDIF-Conference)}, isbn = {978-3-86359-729-0}, pages = {245 -- 254}, year = {2020}, language = {en} } @inproceedings{SildatkeKarwanniKraftetal.2020, author = {Sildatke, Michael and Karwanni, Hendrik and Kraft, Bodo and Schmidts, Oliver and Z{\"u}ndorf, Albert}, title = {Automated Software Quality Monitoring in Research Collaboration Projects}, series = {ICSEW'20: Proceedings of the IEEE/ACM 42nd International Conference on Software Engineering Workshops}, booktitle = {ICSEW'20: Proceedings of the IEEE/ACM 42nd International Conference on Software Engineering Workshops}, doi = {10.1145/3387940.3391478}, pages = {603 -- 610}, year = {2020}, language = {en} } @inproceedings{IomdinaKiselevaKotliaretal.2020, author = {Iomdina, Elena N. and Kiseleva, Anna A. and Kotliar, Konstantin and Luzhnov, Petr V.}, title = {Quantification of Choroidal Blood Flow Using the OCT-A System Based on Voxel Scan Processing}, series = {2020 International Conference on Biomedical Innovations and Applications (BIA)}, booktitle = {2020 International Conference on Biomedical Innovations and Applications (BIA)}, isbn = {978-1-7281-7073-2}, doi = {10.1109/BIA50171.2020.9244511}, pages = {41 -- 44}, year = {2020}, language = {en} } @inproceedings{FrantzBinderBuschetal.2020, author = {Frantz, Cathy and Binder, Matthias and Busch, Konrad and Ebert, Miriam and Heinrich, Andreas and Kaczmarkiewicz, Nadine and Schl{\"o}gl-Knothe, B{\"a}rbel and Kunze, Tobias and Schuhbauer, Christian and Stetka, Markus and Schwager, Christian and Spiegel, Michael and Teixeira Boura, Cristiano Jos{\´e} and Bauer, Thomas and Bonk, Alexander and Eisen, Stefan and Funck, Bernhard}, title = {Basic Engineering of a High Performance Molten Salt Tower Receiver System}, series = {Solar Paces 2020}, booktitle = {Solar Paces 2020}, pages = {1 -- 10}, year = {2020}, language = {en} } @inproceedings{KubalskiMarinkovićButenweg2016, author = {Kubalski, T. and Marinković, Marko and Butenweg, Christoph}, title = {Numerical investigation of masonry infilled R.C. frames}, series = {Brick and Block Masonry. Proceedings of the 16th International Brick and Block Masonry Conference, Padova, Italy, 26-30 June 2016}, booktitle = {Brick and Block Masonry. Proceedings of the 16th International Brick and Block Masonry Conference, Padova, Italy, 26-30 June 2016}, editor = {Modena, Claudio}, publisher = {CRC Press}, address = {Leiden}, isbn = {9781315374963}, pages = {1219 -- 1226}, year = {2016}, language = {en} } @inproceedings{ButenwegMarinkovic2018, author = {Butenweg, Christoph and Marinkovic, Marko}, title = {Damage reduction system for masonry infill walls under seismic loading}, series = {ce/papers}, volume = {2}, booktitle = {ce/papers}, number = {4}, publisher = {Ernst \& Sohn Verlag}, address = {Berlin}, doi = {10.1002/cepa.863}, pages = {267 -- 273}, year = {2018}, abstract = {Reinforced concrete (RC) frames with masonry infills are frequently used in seismic regions all over the world. Generally masonry infills are considered as nonstructural elements and thus are typically neglected in the design process. However, the observations made after strong earthquakes have shown that masonry infills can modify the dynamic behavior of the structure significantly. The consequences were total collapses of buildings and loss of human lives. This paper presents the new system INODIS (Innovative Decoupled Infill System) developed within the European research project INSYSME (Innovative Systems for Earthquake Resistant Masonry Enclosures in RC Buildings). INODIS decouples the frame and the masonry infill by means of special U-shaped rubbers placed in between frame and infill. The effectiveness of the system was investigated by means of full scale tests on RC frames with masonry infills subjected to in-plane and out-of-plane loading. Furthermore small specimen tests were conducted to determine material characteristics of the components and the resistances of the connections. Finally, a micromodel was developed to simulate the in-plane behavior of RC frames infilled with AAC blocks with and without installation of the INODIS system.}, language = {en} } @inproceedings{RajanHoltschoppenDalgueretal.2016, author = {Rajan, Sreelakshmy and Holtschoppen, B. and Dalguer, L. A. and Klinkel, S. and Butenweg, Christoph}, title = {Seismic fragility analysis of a non-conventional reinforced concrete structure considering different uncertainties}, series = {Proceedings of ISMA2016, International Conference on Noise and Vibration Engineering/USD2016, International Conference on Uncertainty in Structural Dynamics, / ISMA 2016, USD 2016}, booktitle = {Proceedings of ISMA2016, International Conference on Noise and Vibration Engineering/USD2016, International Conference on Uncertainty in Structural Dynamics, / ISMA 2016, USD 2016}, editor = {Sas, P.}, publisher = {KU Leuven}, address = {Leuven}, pages = {4213 -- 4225}, year = {2016}, language = {en} } @inproceedings{RajanButenwegDalgueretal.2017, author = {Rajan, S. and Butenweg, Christoph and Dalguer, L. A. and An, J. H. and Renault, P. and Klinkel, S.}, title = {Fragility curves for a three-storey reinforced concrete test structure of the international benchmark SMART 2013}, series = {16th World Conference on Earthquake, 16WCEE 2017 Santiago Chile, January 9th to 13th 2017}, booktitle = {16th World Conference on Earthquake, 16WCEE 2017 Santiago Chile, January 9th to 13th 2017}, publisher = {Chilean Association on Seismology and Earthquake Engineering (ACHISINA)}, year = {2017}, language = {en} } @inproceedings{MerkensHebel2021, author = {Merkens, Torsten and Hebel, Christoph}, title = {Sharing mobility concepts - flexible, sustainable, smart}, series = {Proceedings of the 1st UNITED - Southeast Asia Automotive Interest Group (SAIG)}, booktitle = {Proceedings of the 1st UNITED - Southeast Asia Automotive Interest Group (SAIG)}, isbn = {978-3-902103-94-9}, pages = {43 -- 44}, year = {2021}, language = {en} } @inproceedings{TranStaat2021, author = {Tran, Ngoc Trinh and Staat, Manfred}, title = {FEM shakedown analysis of Kirchhoff-Love plates under uncertainty of strength}, series = {Proceedings of UNCECOMP 2021}, booktitle = {Proceedings of UNCECOMP 2021}, isbn = {978-618-85072-6-5}, doi = {10.7712/120221.8041.19047}, pages = {323 -- 338}, year = {2021}, abstract = {A new formulation to calculate the shakedown limit load of Kirchhoff plates under stochastic conditions of strength is developed. Direct structural reliability design by chance con-strained programming is based on the prescribed failure probabilities, which is an effective approach of stochastic programming if it can be formulated as an equivalent deterministic optimization problem. We restrict uncertainty to strength, the loading is still deterministic. A new formulation is derived in case of random strength with lognormal distribution. Upper bound and lower bound shakedown load factors are calculated simultaneously by a dual algorithm.}, language = {en} } @inproceedings{KaschSchmidtEichleretal.2020, author = {Kasch, Susanne and Schmidt, Thomas and Eichler, Fabian and Thurn, Laura and Jahn, Simon and Bremen, Sebastian}, title = {Solution approaches and process concepts for powder bed-based melting of glass}, series = {Industrializing Additive Manufacturing. Proceedings of AMPA2020}, booktitle = {Industrializing Additive Manufacturing. Proceedings of AMPA2020}, publisher = {Springer}, address = {Cham}, isbn = {978-3-030-54333-4 (Print)}, doi = {10.1007/978-3-030-54334-1_7}, pages = {82 -- 95}, year = {2020}, abstract = {In the study, the process chain of additive manufacturing by means of powder bed fusion will be presented based on the material glass. In order to reliably process components additively, new concepts with different solutions were developed and investigated. Compared to established metallic materials, the properties of glass materials differ significantly. Therefore, the process control was adapted to the material glass in the investigations. With extensive parameter studies based on various glass powders such as borosilicate glass and quartz glass, scientifically proven results on powder bed fusion of glass are presented. Based on the determination of the particle properties with different methods, extensive investigations are made regarding the melting behavior of glass by means of laser beams. Furthermore, the experimental setup was steadily expanded. In addition to the integration of coaxial temperature measurement and regulation, preheating of the building platform is of major importance. This offers the possibility to perform 3D printing at the transformation temperatures of the glass materials. To improve the component's properties, the influence of a subsequent heat treatment was also investigated. The experience gained was incorporated into a new experimental system, which allows a much better exploration of the 3D printing of glass. Currently, studies are being conducted to improve surface texture, building accuracy, and geometrical capabilities using three-dimensional specimen. The contribution shows the development of research in the field of 3D printing of glass, gives an insight into the machine and process engineering as well as an outlook on the possibilities and applications.}, language = {en} } @inproceedings{HoegenDonckerBragardetal.2021, author = {Hoegen, Anne von and Doncker, Rik W. De and Bragard, Michael and Hoegen, Svenja von}, title = {Problem-Based Learning in Automation Engineering: Performing a Remote Laboratory Session Serving Various Educational Attainments}, series = {2021 IEEE Global Engineering Education Conference (EDUCON)}, booktitle = {2021 IEEE Global Engineering Education Conference (EDUCON)}, doi = {10.1109/EDUCON46332.2021.9453925}, pages = {1605 -- 1614}, year = {2021}, language = {en} } @inproceedings{HueningStuettgen2021, author = {H{\"u}ning, Felix and St{\"u}ttgen, Marcel}, title = {Work in Progress: Interdisciplinary projects in times of COVID-19 crisis - challenges, risks and chances}, series = {2021 IEEE Global Engineering Education Conference (EDUCON)}, booktitle = {2021 IEEE Global Engineering Education Conference (EDUCON)}, doi = {10.1109/EDUCON46332.2021.9454006}, pages = {1175 -- 1179}, year = {2021}, language = {en} } @inproceedings{OlderogMohrBegingetal.2021, author = {Olderog, M. and Mohr, P. and Beging, Stefan and Tsoumpas, C. and Ziemons, Karl}, title = {Simulation study on the role of tissue-scattered events in improving sensitivity for a compact time of flight compton positron emission tomograph}, series = {2020 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC)}, booktitle = {2020 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC)}, publisher = {IEEE}, isbn = {978-1-7281-7693-2}, doi = {10.1109/NSS/MIC42677.2020.9507901}, pages = {4 Seiten}, year = {2021}, abstract = {In positron emission tomography improving time, energy and spatial detector resolutions and using Compton kinematics introduces the possibility to reconstruct a radioactivity distribution image from scatter coincidences, thereby enhancing image quality. The number of single scattered coincidences alone is in the same order of magnitude as true coincidences. In this work, a compact Compton camera module based on monolithic scintillation material is investigated as a detector ring module. The detector interactions are simulated with Monte Carlo package GATE. The scattering angle inside the tissue is derived from the energy of the scattered photon, which results in a set of possible scattering trajectories or broken line of response. The Compton kinematics collimation reduces the number of solutions. Additionally, the time of flight information helps localize the position of the annihilation. One of the questions of this investigation is related to how the energy, spatial and temporal resolutions help confine the possible annihilation volume. A comparison of currently technically feasible detector resolutions (under laboratory conditions) demonstrates the influence on this annihilation volume and shows that energy and coincidence time resolution have a significant impact. An enhancement of the latter from 400 ps to 100 ps leads to a smaller annihilation volume of around 50\%, while a change of the energy resolution in the absorber layer from 12\% to 4.5\% results in a reduction of 60\%. The inclusion of single tissue-scattered data has the potential to increase the sensitivity of a scanner by a factor of 2 to 3 times. The concept can be further optimized and extended for multiple scatter coincidences and subsequently validated by a reconstruction algorithm.}, language = {en} } @inproceedings{ThomaFisherBraun2020, author = {Thoma, Andreas and Fisher, Alex and Braun, Carsten}, title = {Improving the px4 avoid algorithm by bio-inspired flight strategies}, series = {DLRK2020 - „Luft- und Raumfahrt - Verantwortung in allen Dimensionen"}, booktitle = {DLRK2020 - „Luft- und Raumfahrt - Verantwortung in allen Dimensionen"}, pages = {10 Seiten}, year = {2020}, language = {en} } @inproceedings{BornheimGriegerBialonski2021, author = {Bornheim, Tobias and Grieger, Niklas and Bialonski, Stephan}, title = {FHAC at GermEval 2021: Identifying German toxic, engaging, and fact-claiming comments with ensemble learning}, series = {Proceedings of the GermEval 2021 Workshop on the Identification of Toxic, Engaging, and Fact-Claiming Comments : 17th Conference on Natural Language Processing KONVENS 2021}, booktitle = {Proceedings of the GermEval 2021 Workshop on the Identification of Toxic, Engaging, and Fact-Claiming Comments : 17th Conference on Natural Language Processing KONVENS 2021}, publisher = {Heinrich Heine University}, address = {D{\"u}sseldorf}, doi = {10.48415/2021/fhw5-x128}, pages = {105 -- 111}, year = {2021}, language = {en} } @inproceedings{KernImaniVashianiTimmermanns2021, author = {Kern, Alexander and Imani Vashiani, Anahita and Timmermanns, Tobias}, title = {Threat for human beings due to touch voltages and body currents caused by direct lightning strikes in case of non-isolated lightning protection systems using natural components}, series = {35th International Conference on Lightning Protection (ICLP) and XVI International Symposium on Lightning Protection (SIPDA)}, booktitle = {35th International Conference on Lightning Protection (ICLP) and XVI International Symposium on Lightning Protection (SIPDA)}, publisher = {IEEE}, isbn = {978-1-6654-2346-5}, doi = {10.1109/ICLPandSIPDA54065.2021.9627465}, pages = {8 Seiten}, year = {2021}, abstract = {For typical cases of non-isolated lightning protection systems (LPS) the impulse currents are investigated which may flow through a human body directly touching a structural part of the LPS. Based on a basic LPS model with conventional down-conductors especially the cases of external and internal steel columns and metal fa{\c{c}}ades are considered and compared. Numerical simulations of the line quantities voltages and currents in the time domain are performed with an equivalent circuit of the entire LPS. As a result it can be stated that by increasing the number of conventional down-conductors and external steel columns the threat for a human being can indeed be reduced, but not down to an acceptable limit. In case of internal steel columns used as natural down-conductors the threat can be reduced sufficiently, depending on the low-resistive connection of the steel columns to the lightning equipotential bonding or the earth termination system, resp. If a metal fa{\c{c}}ade is used the threat for human beings touching is usually very low, if the fa{\c{c}}ade is sufficiently interconnected and multiply connected to the lightning equipotential bonding or the earth termination system, resp.}, language = {en} } @inproceedings{EnglhardWeberArent2021, author = {Englhard, Markus and Weber, Tobias and Arent, Jan-Christoph}, title = {Efficiency enhancement for CFRP-Prepregautoclave manufacturing by means of simulation-assisted loading optimization}, series = {Proceedings of SAMPE Europe Conference 2021}, booktitle = {Proceedings of SAMPE Europe Conference 2021}, pages = {8 Seiten}, year = {2021}, abstract = {A new method for improved autoclave loading within the restrictive framework of helicopter manufacturing is proposed. It is derived from experimental and numerical studies of the curing process and aims at optimizing tooling positions in the autoclave for fast and homogeneous heat-up. The mold positioning is based on two sets of information. The thermal properties of the molds, which can be determined via semi-empirical thermal simulation. The second information is a previously determined distribution of heat transfer coefficients inside the autoclave. Finally, an experimental proof of concept is performed to show a cycle time reduction of up to 31\% using the proposed methodology.}, language = {en} } @inproceedings{AltherrEdererSchaenzleetal.2017, author = {Altherr, Lena and Ederer, Thorsten and Sch{\"a}nzle, Christian and Lorenz, Ulf and Pelz, Peter F.}, title = {Algorithmic system design using scaling and affinity laws}, series = {Operations Research Proceedings 2015}, booktitle = {Operations Research Proceedings 2015}, publisher = {Springer}, address = {Cham}, isbn = {978-3-319-42901-4}, doi = {10.1007/978-3-319-42902-1}, pages = {605 -- 611}, year = {2017}, abstract = {Energy-efficient components do not automatically lead to energy-efficient systems. Technical Operations Research (TOR) shifts the focus from the single component to the system as a whole and finds its optimal topology and operating strategy simultaneously. In previous works, we provided a preselected construction kit of suitable components for the algorithm. This approach may give rise to a combinatorial explosion if the preselection cannot be cut down to a reasonable number by human intuition. To reduce the number of discrete decisions, we integrate laws derived from similarity theory into the optimization model. Since the physical characteristics of a production series are similar, it can be described by affinity and scaling laws. Making use of these laws, our construction kit can be modeled more efficiently: Instead of a preselection of components, it now encompasses whole model ranges. This allows us to significantly increase the number of possible set-ups in our model. In this paper, we present how to embed this new formulation into a mixed-integer program and assess the run time via benchmarks. We present our approach on the example of a ventilation system design problem.}, language = {en} } @inproceedings{HauggKreyerKemperetal.2020, author = {Haugg, Albert Thomas and Kreyer, J{\"o}rg and Kemper, Hans and Hatesuer, Katerina and Esch, Thomas}, title = {Heat exchanger for ORC. adaptability and optimisation potentials}, series = {IIR International Rankine 2020 Conference}, booktitle = {IIR International Rankine 2020 Conference}, doi = {10.18462/iir.rankine.2020.1224}, pages = {10 Seiten}, year = {2020}, abstract = {The recovery of waste heat requires heat exchangers to extract it from a liquid or gaseous medium into another working medium, a refrigerant. In Organic Rankine Cycles (ORC) on Combustion Engines there are two major heat sources, the exhaust gas and the water/glycol fluid from the engine's cooling circuit. A heat exchanger design must be adapted to the different requirements and conditions resulting from the heat sources, fluids, system configurations, geometric restrictions, and etcetera. The Stacked Shell Cooler (SSC) is a new and very specific design of a plate heat exchanger, created by AKG, which allows with a maximum degree of freedom the optimization of heat exchange rate and the reduction of the related pressure drop. This optimization in heat exchanger design for ORC systems is even more important, because it reduces the energy consumption of the system and therefore maximizes the increase in overall efficiency of the engine.}, language = {en} } @inproceedings{NikolovskiRekeElsenetal.2021, author = {Nikolovski, Gjorgji and Reke, Michael and Elsen, Ingo and Schiffer, Stefan}, title = {Machine learning based 3D object detection for navigation in unstructured environments}, series = {2021 IEEE Intelligent Vehicles Symposium Workshops (IV Workshops)}, booktitle = {2021 IEEE Intelligent Vehicles Symposium Workshops (IV Workshops)}, publisher = {IEEE}, isbn = {978-1-6654-7921-9}, doi = {10.1109/IVWorkshops54471.2021.9669218}, pages = {236 -- 242}, year = {2021}, abstract = {In this paper we investigate the use of deep neural networks for 3D object detection in uncommon, unstructured environments such as in an open-pit mine. While neural nets are frequently used for object detection in regular autonomous driving applications, more unusual driving scenarios aside street traffic pose additional challenges. For one, the collection of appropriate data sets to train the networks is an issue. For another, testing the performance of trained networks often requires tailored integration with the particular domain as well. While there exist different solutions for these problems in regular autonomous driving, there are only very few approaches that work for special domains just as well. We address both the challenges above in this work. First, we discuss two possible ways of acquiring data for training and evaluation. That is, we evaluate a semi-automated annotation of recorded LIDAR data and we examine synthetic data generation. Using these datasets we train and test different deep neural network for the task of object detection. Second, we propose a possible integration of a ROS2 detector module for an autonomous driving platform. Finally, we present the performance of three state-of-the-art deep neural networks in the domain of 3D object detection on a synthetic dataset and a smaller one containing a characteristic object from an open-pit mine.}, language = {en} } @inproceedings{SchaenzleAltherrEdereretal.2015, author = {Sch{\"a}nzle, Christian and Altherr, Lena and Ederer, Thorsten and Lorenz, Ulf and Pelz, Peter F.}, title = {As good as it can be: Ventilation system design by a combined scaling and discrete optimization method}, series = {Proceedings of FAN 2015}, booktitle = {Proceedings of FAN 2015}, pages = {1 -- 11}, year = {2015}, abstract = {The understanding that optimized components do not automatically lead to energy-efficient systems sets the attention from the single component on the entire technical system. At TU Darmstadt, a new field of research named Technical Operations Research (TOR) has its origin. It combines mathematical and technical know-how for the optimal design of technical systems. We illustrate our optimization approach in a case study for the design of a ventilation system with the ambition to minimize the energy consumption for a temporal distribution of diverse load demands. By combining scaling laws with our optimization methods we find the optimal combination of fans and show the advantage of the use of multiple fans.}, language = {en} } @inproceedings{AltherrEdererFarnetaneetal.2017, author = {Altherr, Lena and Ederer, Thorsten and Farnetane, Lucas S. and P{\"o}ttgen, Philipp and Verg{\´e}, Angela and Pelz, Peter F.}, title = {Multicriterial design of a hydrostatic transmission system via mixed-integer programming}, series = {Operations Research Proceedings 2015}, booktitle = {Operations Research Proceedings 2015}, publisher = {Springer}, address = {Cham}, isbn = {978-3-319-42901-4}, doi = {10.1007/978-3-319-42902-1_41}, pages = {301 -- 307}, year = {2017}, abstract = {In times of planned obsolescence the demand for sustainability keeps growing. Ideally, a technical system is highly reliable, without failures and down times due to fast wear of single components. At the same time, maintenance should preferably be limited to pre-defined time intervals. Dispersion of load between multiple components can increase a system's reliability and thus its availability inbetween maintenance points. However, this also results in higher investment costs and additional efforts due to higher complexity. Given a specific load profile and resulting wear of components, it is often unclear which system structure is the optimal one. Technical Operations Research (TOR) finds an optimal structure balancing availability and effort. We present our approach by designing a hydrostatic transmission system.}, language = {en} } @inproceedings{LorenzAltherrPelz2020, author = {Lorenz, Imke-Sophie and Altherr, Lena and Pelz, Peter F.}, title = {Resilience enhancement of critical infrastructure - graph-theoretical resilience analysis of the water distribution system in the German city of Darmstadt}, series = {14th WCEAM Proceedings}, booktitle = {14th WCEAM Proceedings}, publisher = {Springer}, address = {Cham}, isbn = {978-3-030-64228-0}, doi = {10.1007/978-3-030-64228-0_13}, pages = {137 -- 149}, year = {2020}, abstract = {Water suppliers are faced with the great challenge of achieving high-quality and, at the same time, low-cost water supply. Since climatic and demographic influences will pose further challenges in the future, the resilience enhancement of water distribution systems (WDS), i.e. the enhancement of their capability to withstand and recover from disturbances, has been in particular focus recently. To assess the resilience of WDS, graph-theoretical metrics have been proposed. In this study, a promising approach is first physically derived analytically and then applied to assess the resilience of the WDS for a district in a major German City. The topology based resilience index computed for every consumer node takes into consideration the resistance of the best supply path as well as alternative supply paths. This resistance of a supply path is derived to be the dimensionless pressure loss in the pipes making up the path. The conducted analysis of a present WDS provides insight into the process of actively influencing the resilience of WDS locally and globally by adding pipes. The study shows that especially pipes added close to the reservoirs and main branching points in the WDS result in a high resilience enhancement of the overall WDS.}, language = {en} } @inproceedings{SchaenzleAltherrEdereretal.2015, author = {Sch{\"a}nzle, Christian and Altherr, Lena and Ederer, Thorsten and Pelz, Peter}, title = {TOR - Towards the energetically optimal ventilation system}, pages = {1 Seite}, year = {2015}, language = {en} } @inproceedings{SteuerDankertSharmaBlecketal.2017, author = {Steuer-Dankert, Linda and Sharma, Mamta Rameshwarlal and Bleck, Wolfgang and Leicht-Scholten, Carmen}, title = {Innovation through Diversity - Development of a Diversity and Innovation management concept}, series = {International Conference on Innovation and Management : IAM23017S : Date: July 4-7, 2017, Osaka, Japan}, booktitle = {International Conference on Innovation and Management : IAM23017S : Date: July 4-7, 2017, Osaka, Japan}, editor = {Farn, C. K.}, publisher = {Kuang Hui Chiu}, address = {Osaka}, issn = {2218-6387}, pages = {Panel C}, year = {2017}, abstract = {Acknowledging that a diverse workforce could be a potential source of innovation, the current research deals with the fine details of why diversity management is central to achieving innovation in heterogeneous research groups and how this could be effectively realized in an organization. The types of heterogeneities addressed mainly include gender, qualification, academic discipline and intercultural perspectives. The type of organization being dealt with in this work is a complex association of research institutes at a technical university in Germany (RWTH Aachen University), namely a 'Cluster of Excellence', whereby several institutes of the university work collaboratively in different sub-projects. The 'Cluster of Excellence' is a part of the 'Excellence Initiative' of the German federal and state governments German Research Foundation (DFG) and German Council of Science and Humanities, with the ultimate aim of promoting cutting-edge research. To support interdisciplinary collaboration and thus the performance of the cluster, the development of a diversity and innovation management concept is presently in the conceptual phase and will be described in the frame of this paper. The 3-S-Diversity Model, composed of the three elements: skills, structure and strategy, serves as a basis for the development of the concept. The proposed concept consists of six phases; the first two phases lay the ground work by developing an understanding of the status quo on the forms of diversity in the Cluster of Excellence, the type of organizational structure of the member institutes and the varieties of specialist work cultures of the same. The third and the fourth phases build up on this foundation by means of qualitative and quantitative studies. While the third phase deals with the sensitization of the management level to the close connection between diversity and innovation; the need to manage them thereafter and find tailor-made methods of doing so, the fourth phase shall mainly focus on the mindset of the employees in this regard. The fifth phase shall consolidate the learnings and the ideas developed in the course of the first four phases into an implementable strategy. The ultimate phase shall be the implementation of this concept in the Cluster. The first three phases have been accomplished successfully and the preliminary results are already available.}, language = {en} } @inproceedings{BlaneckBornheimGriegeretal.2022, author = {Blaneck, Patrick Gustav and Bornheim, Tobias and Grieger, Niklas and Bialonski, Stephan}, title = {Automatic readability assessment of german sentences with transformer ensembles}, series = {Proceedings of the GermEval 2022 Workshop on Text Complexity Assessment of German Text}, booktitle = {Proceedings of the GermEval 2022 Workshop on Text Complexity Assessment of German Text}, publisher = {Association for Computational Linguistics}, address = {Potsdam}, doi = {10.48550/arXiv.2209.04299}, pages = {57 -- 62}, year = {2022}, abstract = {Reliable methods for automatic readability assessment have the potential to impact a variety of fields, ranging from machine translation to self-informed learning. Recently, large language models for the German language (such as GBERT and GPT-2-Wechsel) have become available, allowing to develop Deep Learning based approaches that promise to further improve automatic readability assessment. In this contribution, we studied the ability of ensembles of fine-tuned GBERT and GPT-2-Wechsel models to reliably predict the readability of German sentences. We combined these models with linguistic features and investigated the dependence of prediction performance on ensemble size and composition. Mixed ensembles of GBERT and GPT-2-Wechsel performed better than ensembles of the same size consisting of only GBERT or GPT-2-Wechsel models. Our models were evaluated in the GermEval 2022 Shared Task on Text Complexity Assessment on data of German sentences. On out-of-sample data, our best ensemble achieved a root mean squared error of 0:435.}, language = {en} } @inproceedings{CzarneckiDietze2017, author = {Czarnecki, Christian and Dietze, Christian}, title = {Domain-Specific reference modeling in the telecommunications industry}, series = {DESRIST 2017: Designing the Digital Transformation}, booktitle = {DESRIST 2017: Designing the Digital Transformation}, editor = {Maedche, Alexander and vom Brocke, Jan and Hevner, Alan}, publisher = {Springer}, address = {Cham}, isbn = {978-3-319-59144-5}, doi = {10.1007/978-3-319-59144-5_19}, pages = {313 -- 329}, year = {2017}, abstract = {The telecommunications industry is currently going through a major transformation. In this context, the enhanced Telecom Operations Map (eTOM) is a domain-specific process reference model that is offered by the industry organization TM Forum. In practice, eTOM is well accepted and confirmed as de facto standard. It provides process definitions and process flows on different levels of detail. This article discusses the reference modeling of eTOM, i.e., the design, the resulting artifact, and its evaluation based on three project cases. The application of eTOM in three projects illustrates the design approach and concrete models on strategic and operational levels. The article follows the Design Science Research (DSR) paradigm. It contributes with concrete design artifacts to the transformational needs of the telecommunications industry and offers lessons-learned from a general DSR perspective.}, language = {en} } @inproceedings{NursinskiStolbergGangatharanCzarnecki2016, author = {Nursinski-Stolberg, Andr{\´e} and Gangatharan, Kiritharan and Czarnecki, Christian}, title = {Development of a subject-oriented reference process model for the telecommunications industry}, series = {GI Edition Proceedings Band 259 INFORMATIK 2016}, booktitle = {GI Edition Proceedings Band 259 INFORMATIK 2016}, editor = {Mayr, Heinrich C. and Pinzger, Martin}, publisher = {Gesellschaft f{\"u}r Informatik e.V.}, address = {Bonn}, isbn = {9783885796534}, issn = {1617-5468}, pages = {699 -- 712}, year = {2016}, abstract = {Generally the usage of reference models can be structured top-down or bottom-up. The practical need of agile change and flexible organizational implementation requires a consistent mapping to an operational level. In this context, well-established reference process models are typically structured top-down. The subject-oriented Business Process Management (sBPM) offers a modeling concept that is structured bottom-up and concentrates on the process actors on an operational level. This paper applies sBPM to the enhanced Telecom Operations Map (eTOM), a well-accepted reference process model in the telecommunications industry. The resulting design artifact is a concrete example for a combination of a bottom-up and top-down developed reference model. The results are evaluated and confirmed in practical context through the involvement of the industry body TMForum.}, language = {en} } @inproceedings{CzarneckiWinkelmannSpiliopoulou2011, author = {Czarnecki, Christian and Winkelmann, Axel and Spiliopoulou, Myra}, title = {Making business systems in the telecommunication industry more customer-oriented}, series = {Information Systems Development : Business Systems and Services: Modeling and Development}, booktitle = {Information Systems Development : Business Systems and Services: Modeling and Development}, editor = {Pokorny, Jaroslav and Repa, Vaclav and Richta, Karel and Wojtkowski, Wita and Linger, Henry and Barry, Chris and Lang, Michael}, publisher = {Springer}, address = {New York}, isbn = {978-1-4419-9645-9 (Print)}, doi = {10.1007/978-1-4419-9790-6_14}, pages = {169 -- 180}, year = {2011}, abstract = {Market changes have forced telecommunication companies to transform their business. Increased competition, short innovation cycles, changed usage patterns, increased customer expectations and cost reduction are the main drivers. Our objective is to analyze to what extend transformation projects have improved the orientation towards the end-customers. Therefore, we selected 38 real-life case studies that are dealing with customer orientation. Our analysis is based on a telecommunication-specific framework that aligns strategy, business processes and information systems. The result of our analysis shows the following: transformation projects that aim to improve the customer orientation are combined with clear goals on costs and revenue of the enterprise. These projects are usually directly linked to the customer touch points, but also to the development and provisioning of products. Furthermore, the analysis shows that customer orientation is not the sole trigger for transformation. There is no one-fits-all solution; rather, improved customer orientation needs aligned changes of business processes as well as information systems related to different parts of the company.}, language = {en} } @inproceedings{AmirBauckhageChircuetal.2022, author = {Amir, Malik and Bauckhage, Christian and Chircu, Alina and Czarnecki, Christian and Knopf, Christian and Piatkowski, Nico and Sultanow, Eldar}, title = {What can we expect from quantum (digital) twins?}, publisher = {AIS Electronic Library (AISeL)}, pages = {1 -- 14}, year = {2022}, abstract = {Digital twins enable the modeling and simulation of real-world entities (objects, processes or systems), resulting in improvements in the associated value chains. The emerging field of quantum computing holds tremendous promise for evolving this virtualization towards Quantum (Digital) Twins (QDT) and ultimately Quantum Twins (QT). The quantum (digital) twin concept is not a contradiction in terms - but instead describes a hybrid approach that can be implemented using the technologies available today by combining classical computing and digital twin concepts with quantum processing. This paper presents the status quo of research and practice on quantum (digital) twins. It also discuses their potential to create competitive advantage through real-time simulation of highly complex, interconnected entities that helps companies better address changes in their environment and differentiate their products and services.}, language = {en} } @inproceedings{RitschelStenzelCzarneckietal.2021, author = {Ritschel, Konstantin and Stenzel, Adina and Czarnecki, Christian and Hong, Chin-Gi}, title = {Realizing robotic process automation potentials: an architectural perspective on a real-life implementation case}, series = {GI Edition Proceedings Band 314 "INFORMATIK 2021" Computer Science \& Sustainability}, booktitle = {GI Edition Proceedings Band 314 "INFORMATIK 2021" Computer Science \& Sustainability}, editor = {Gesellschaft f{\"u}r Informatik e.V. (GI),}, publisher = {K{\"o}llen}, address = {Bonn}, isbn = {9783885797081}, issn = {1617-5468}, pages = {1303 -- 1311}, year = {2021}, abstract = {The initial idea of Robotic Process Automation (RPA) is the automation of business processes through a simple emulation of user input and output by software robots. Hence, it can be assumed that no changes of the used software systems and existing Enterprise Architecture (EA) is required. In this short, practical paper we discuss this assumption based on a real-life implementation project. We show that a successful RPA implementation might require architectural work during analysis, implementation, and migration. As practical paper we focus on exemplary lessons-learned and new questions related to RPA and EA.}, language = {en} } @inproceedings{AuthCzarneckiBensberg2019, author = {Auth, Gunnar and Czarnecki, Christian and Bensberg, Frank}, title = {Impact of robotic process automation on enterprise architectures}, series = {GI Edition Proceedings Band 295 INFORMATIK 2019, Workshop-Beitr{\"a}ge}, booktitle = {GI Edition Proceedings Band 295 INFORMATIK 2019, Workshop-Beitr{\"a}ge}, editor = {Draude, Claude and Lange, Martin and Sick, Bernhard and Gesellschaft f{\"u}r Informatik e.V. (GI),}, publisher = {K{\"o}llen}, address = {Bonn}, isbn = {9783885796893}, issn = {1617-5468}, doi = {10.18420/inf2019_ws05}, pages = {59 -- 65}, year = {2019}, abstract = {The initial idea of Robotic Process Automation (RPA) is the automation of business processes through the presentation layer of existing application systems. For this simple emulation of user input and output by software robots, no changes of the systems and architecture is required. However, considering strategic aspects of aligning business and technology on an enterprise level as well as the growing capabilities of RPA driven by artificial intelligence, interrelations between RPA and Enterprise Architecture (EA) become visible and pose new questions. In this paper we discuss the relationship between RPA and EA in terms of perspectives and implications. As workin- progress we focus on identifying new questions and research opportunities related to RPA and EA.}, language = {en} } @inproceedings{BrockmannSultanowCzarnecki2019, author = {Brockmann, Carsten and Sultanow, Eldar and Czarnecki, Christian}, title = {Is enterprise architecture still relevant in the digital age?}, series = {GI Edition Proceedings Band 295 INFORMATIK 2019, Workshop-Beitr{\"a}ge}, booktitle = {GI Edition Proceedings Band 295 INFORMATIK 2019, Workshop-Beitr{\"a}ge}, editor = {Draude, Claude and Lange, Martin and Sick, Bernhard}, publisher = {K{\"o}llen}, address = {Bonn}, isbn = {9783885796893}, issn = {1617-5468}, doi = {10.18420/inf2019_ws01}, pages = {21 -- 21}, year = {2019}, language = {en} } @inproceedings{BensbergAuthCzarneckietal.2018, author = {Bensberg, Frank and Auth, Gunnar and Czarnecki, Christian and W{\"o}rndle, Christopher}, title = {Transforming literature-intensive research processes through text analytics - design, implementation and lessons learned}, editor = {Kemal İlter, H.}, doi = {10.6084/m9.figshare.7582073.v1}, pages = {9 Seiten}, year = {2018}, abstract = {The continuing growth of scientific publications raises the question how research processes can be digitalized and thus realized more productively. Especially in information technology fields, research practice is characterized by a rapidly growing volume of publications. For the search process various information systems exist. However, the analysis of the published content is still a highly manual task. Therefore, we propose a text analytics system that allows a fully digitalized analysis of literature sources. We have realized a prototype by using EBSCO Discovery Service in combination with IBM Watson Explorer and demonstrated the results in real-life research projects. Potential addressees are research institutions, consulting firms, and decision-makers in politics and business practice.}, language = {en} } @inproceedings{BrockmannSultanowCzarnecki2018, author = {Brockmann, Carsten and Sultanow, Eldar and Czarnecki, Christian}, title = {Enterprise architectures between agility and traditional methodologies}, series = {GI Edition Proceedings Band 285 Workshops der INFORMATIK 2018}, booktitle = {GI Edition Proceedings Band 285 Workshops der INFORMATIK 2018}, editor = {Czarnecki, Christian and Brockmann, Carsten and Sultanow, Eldar and Koschmider, Agnes and Selzer, Annika and Gesellschaft f{\"u}r Informatik e. V.,}, publisher = {K{\"o}llen}, address = {Bonn}, isbn = {9783885796794}, issn = {1617-5468}, pages = {1 Seite}, year = {2018}, abstract = {For this year's workshop on Enterpirse Architecture in Research and Practice we have received eight submissions from which four have passed the rigorous peer-review. The acceptance quote of 50\% assures that only advancements in the field are included in our workshop.}, language = {en} } @inproceedings{CzarneckiHeuserSpiliopoulou2009, author = {Czarnecki, Christian and Heuser, Marcus and Spiliopoulou, Myra}, title = {How does the implementation of a next generation network influence a telecommunication company?}, series = {European and Mediterranean Conference on Information Systems}, booktitle = {European and Mediterranean Conference on Information Systems}, editor = {Irani, Zahir}, publisher = {Brunel University}, address = {London}, isbn = {9781902316697}, pages = {1 -- 11}, year = {2009}, abstract = {As the potential of a Next Generation Network (NGN) is recognized, telecommunication companies consider switching to it. Although the implementation of an NGN seems to be merely a modification of the network infrastructure, it may trigger or require changes in the whole company and even influence the company strategy. To capture the effects of NGN we propose a framework based on concepts of business engineering and technical recommendations for the introduction of NGN technology. The specific design of solutions for the layers "Strategy", "Processes" and "Information Systems" as well as their interdependencies are an essential characteristic of the developed framework. We have per-formed a case study on NGN implementation and observed that all layers captured by our framework are influenced by the introduction of an NGN.}, language = {en} } @inproceedings{EngemannBadriWenningetal.2019, author = {Engemann, Heiko and Badri, Sriram and Wenning, Marius and Kallweit, Stephan}, title = {Implementation of an Autonomous Tool Trolley in a Production Line}, series = {Advances in Service and Industrial Robotics. RAAD 2019. Advances in Intelligent Systems and Computing, vol 980}, booktitle = {Advances in Service and Industrial Robotics. RAAD 2019. Advances in Intelligent Systems and Computing, vol 980}, publisher = {Springer}, address = {Cham}, isbn = {978-3-030-19648-6}, doi = {10.1007/978-3-030-19648-6_14}, pages = {117 -- 125}, year = {2019}, language = {en} } @inproceedings{KirschMatareFerreinetal.2020, author = {Kirsch, Maximilian and Matar{\´e}, Victor and Ferrein, Alexander and Schiffer, Stefan}, title = {Integrating golog++ and ROS for Practical and Portable High-level Control}, series = {12th International Conference on Agents and Artificial Intelligence}, booktitle = {12th International Conference on Agents and Artificial Intelligence}, doi = {10.5220/0008984406920699}, year = {2020}, language = {en} } @inproceedings{PohleFroehlichDalitzRichteretal.2020, author = {Pohle-Fr{\"o}hlich, Regina and Dalitz, Christoph and Richter, Charlotte and Hahnen, Tobias and St{\"a}udle, Benjamin and Albracht, Kirsten}, title = {Estimation of muscle fascicle orientation in ultrasonic images}, series = {VISIGRAPP 2020 - Proceedings of the 15th International Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications, 5}, booktitle = {VISIGRAPP 2020 - Proceedings of the 15th International Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications, 5}, pages = {79 -- 86}, year = {2020}, language = {en} } @inproceedings{HoevelerJanser2016, author = {Hoeveler, Bastian and Janser, Frank}, title = {The aerodynamically optimized design of a fan-in-wing duct}, series = {Applied Aerodynamics Research Conference 2016, Bristol, GB, Jul 19-21, 2016}, booktitle = {Applied Aerodynamics Research Conference 2016, Bristol, GB, Jul 19-21, 2016}, isbn = {1-85768-371-4}, pages = {1 -- 10}, year = {2016}, language = {en} } @inproceedings{GrundmannBauerBorchersetal.2019, author = {Grundmann, Jan Thimo and Bauer, Wlademar and Borchers, Kai and Dumont, Etienne and Grimm, Christian D. and Ho, Tra-Mi and Jahnke, Rico and Koch, Aaron D. and Lange, Caroline and Maiwald, Volker and Meß, Jan-Gerd and Mikulz, Eugen and Quantius, Dominik and Reershemius, Siebo and Renger, Thomas and Sasaki, Kaname and Seefeldt, Patric and Spietz, Peter and Spr{\"o}witz, Tom and Sznajder, Maciej and Toth, Norbert and Ceriotti, Matteo and McInnes, Colin and Peloni, Alessandro and Biele, Jens and Krause, Christian and Dachwald, Bernd and Hercik, David and Lichtenheldt, Roy and Wolff, Friederike and Koncz, Alexander and Pelivan, Ivanka and Schmitz, Nicole and Boden, Ralf and Riemann, Johannes and Seboldt, Wolfgang and Wejmo, Elisabet and Ziach, Christian and Mikschl, Tobias and Montenegro, Sergio and Ruffer, Michael and Cordero, Federico and Tardivel, Simon}, title = {Solar sails for planetary defense \& high-energy missions}, series = {IEEE Aerospace Conference Proceedings}, booktitle = {IEEE Aerospace Conference Proceedings}, doi = {10.1109/AERO.2019.8741900}, pages = {1 -- 21}, year = {2019}, abstract = {20 years after the successful ground deployment test of a (20 m) 2 solar sail at DLR Cologne, and in the light of the upcoming U.S. NEAscout mission, we provide an overview of the progress made since in our mission and hardware design studies as well as the hardware built in the course of our solar sail technology development. We outline the most likely and most efficient routes to develop solar sails for useful missions in science and applications, based on our developed `now-term' and near-term hardware as well as the many practical and managerial lessons learned from the DLR-ESTEC Gossamer Roadmap. Mission types directly applicable to planetary defense include single and Multiple NEA Rendezvous ((M)NR) for precursor, monitoring and follow-up scenarios as well as sail-propelled head-on retrograde kinetic impactors (RKI) for mitigation. Other mission types such as the Displaced L1 (DL1) space weather advance warning and monitoring or Solar Polar Orbiter (SPO) types demonstrate the capability of near-term solar sails to achieve asteroid rendezvous in any kind of orbit, from Earth-coorbital to extremely inclined and even retrograde orbits. Some of these mission types such as SPO, (M)NR and RKI include separable payloads. For one-way access to the asteroid surface, nanolanders like MASCOT are an ideal match for solar sails in micro-spacecraft format, i.e. in launch configurations compatible with ESPA and ASAP secondary payload platforms. Larger landers similar to the JAXA-DLR study of a Jupiter Trojan asteroid lander for the OKEANOS mission can shuttle from the sail to the asteroids visited and enable multiple NEA sample-return missions. The high impact velocities and re-try capability achieved by the RKI mission type on a final orbit identical to the target asteroid's but retrograde to its motion enables small spacecraft size impactors to carry sufficient kinetic energy for deflection.}, language = {en} } @inproceedings{SadeghfamSadeghiAhangarElgamaletal.2019, author = {Sadeghfam, Arash and Sadeghi-Ahangar, A. and Elgamal, Abdelrahman and Heuermann, Holger}, title = {Design and Development of a Novel Self-Igniting Microwave Plasma Jet for Industrial Applications}, series = {IEEE MTT-S International Microwave Symposium Digest}, booktitle = {IEEE MTT-S International Microwave Symposium Digest}, isbn = {978-172811309-8}, pages = {63 -- 66}, year = {2019}, language = {en} } @inproceedings{UlmerBraunLaietal.2019, author = {Ulmer, Jessica and Braun, Sebastian and Lai, Chow Yin and Cheng, Chi-Tsun and Wollert, J{\"o}rg}, title = {Generic integration of VR and AR in product lifecycles based on CAD models}, series = {Proceedings of The 23rd World Multi-Conference on Systemics, Cybernetics and Informatics: WMSCI 2019}, booktitle = {Proceedings of The 23rd World Multi-Conference on Systemics, Cybernetics and Informatics: WMSCI 2019}, year = {2019}, language = {en} } @inproceedings{FingerdeVriesVosetal.2020, author = {Finger, Felix and de Vries, Reynard and Vos, Roelof and Braun, Carsten and Bil, Cees}, title = {A comparison of hybrid-electric aircraft sizing methods}, series = {AIAA Scitech 2020 Forum}, booktitle = {AIAA Scitech 2020 Forum}, doi = {10.2514/6.2020-1006}, pages = {31 Seiten}, year = {2020}, language = {en} } @inproceedings{HingleyDikta2019, author = {Hingley, Peter and Dikta, Gerhard}, title = {Finding a well performing box-jenkins forecasting model for annualised patent filings counts}, series = {International Symposium on Forecasting, Thessaloniki, Greece, June 2019}, booktitle = {International Symposium on Forecasting, Thessaloniki, Greece, June 2019}, pages = {24 Folien}, year = {2019}, language = {en} } @inproceedings{KreyerMuellerEsch2020, author = {Kreyer, J{\"o}rg and M{\"u}ller, Marvin and Esch, Thomas}, title = {A Map-Based Model for the Determination of Fuel Consumption for Internal Combustion Engines as a Function of Flight Altitude}, series = {Deutscher Luft- und Raumfahrtkongress 2019, „Luft- und Raumfahrt - technologische Br{\"u}cke in die Zukunft", Darmstadt, 30. September bis 2. Oktober 2019}, booktitle = {Deutscher Luft- und Raumfahrtkongress 2019, „Luft- und Raumfahrt - technologische Br{\"u}cke in die Zukunft", Darmstadt, 30. September bis 2. Oktober 2019}, publisher = {Deutsche Gesellschaft f{\"u}r Luft- und Raumfahrt - Lilienthal-Oberth e.V}, address = {Bonn}, doi = {10.25967/490162}, pages = {13 Seiten}, year = {2020}, language = {en} } @inproceedings{FingerGoettenBraunetal.2019, author = {Finger, Felix and G{\"o}tten, Falk and Braun, Carsten and Bil, Cees}, title = {Cost Estimation Methods for Hybrid-Electric General Aviation Aircraft}, series = {Asia Pacific International Symposium on Aerospace Technology. APISAT 2019}, booktitle = {Asia Pacific International Symposium on Aerospace Technology. APISAT 2019}, pages = {1 -- 13}, year = {2019}, language = {en} } @inproceedings{FingerBraunBil2020, author = {Finger, Felix and Braun, Carsten and Bil, Cees}, title = {Comparative assessment of parallel-hybrid-electric propulsion systems for four different aircraft}, series = {AIAA SciTech Forum 2020, 06.01.2020 - 10.01.2020, Orlando}, booktitle = {AIAA SciTech Forum 2020, 06.01.2020 - 10.01.2020, Orlando}, doi = {10.2514/6.2020-1502}, pages = {15 Seiten}, year = {2020}, language = {en} } @inproceedings{DinghoferHartung2020, author = {Dinghofer, Kai and Hartung, Frank}, title = {Analysis of Criteria for the Selection of Machine Learning Frameworks}, series = {2020 International Conference on Computing, Networking and Communications (ICNC)}, booktitle = {2020 International Conference on Computing, Networking and Communications (ICNC)}, doi = {10.1109/ICNC47757.2020.9049650}, pages = {373 -- 377}, year = {2020}, language = {en} } @inproceedings{RekePeterSchulteTiggesetal.2020, author = {Reke, Michael and Peter, Daniel and Schulte-Tigges, Joschua and Schiffer, Stefan and Ferrein, Alexander and Walter, Thomas and Matheis, Dominik}, title = {A Self-Driving Car Architecture in ROS2}, series = {2020 International SAUPEC/RobMech/PRASA Conference, Cape Town, South Africa}, booktitle = {2020 International SAUPEC/RobMech/PRASA Conference, Cape Town, South Africa}, isbn = {978-1-7281-4162-6}, doi = {10.1109/SAUPEC/RobMech/PRASA48453.2020.9041020}, pages = {1 -- 6}, year = {2020}, language = {en} } @inproceedings{PaulsenHoffstadtKrafftetal.2020, author = {Paulsen, Svea and Hoffstadt, Kevin and Krafft, Simone and Leite, A. and Zang, J. and Fonseca-Zang, W. and Kuperjans, Isabel}, title = {Continuous biogas production from sugarcane as sole substrate}, series = {Energy Reports}, volume = {6}, booktitle = {Energy Reports}, number = {Supplement 1}, publisher = {Elsevier}, doi = {10.1016/j.egyr.2019.08.035}, pages = {153 -- 158}, year = {2020}, language = {en} } @inproceedings{FingerKhalsaKreyeretal.2019, author = {Finger, Felix and Khalsa, R. and Kreyer, J{\"o}rg and Mayntz, Joscha and Braun, Carsten and Dahmann, Peter and Esch, Thomas and Kemper, Hans and Schmitz, O. and Bragard, Michael}, title = {An approach to propulsion system modelling for the conceptual design of hybrid-electric general aviation aircraft}, series = {Deutscher Luft- und Raumfahrtkongress 2019, 30.9.-2.10.2019, Darmstadt}, booktitle = {Deutscher Luft- und Raumfahrtkongress 2019, 30.9.-2.10.2019, Darmstadt}, pages = {15 Seiten}, year = {2019}, abstract = {In this paper, an approach to propulsion system modelling for hybrid-electric general aviation aircraft is presented. Because the focus is on general aviation aircraft, only combinations of electric motors and reciprocating combustion engines are explored. Gas turbine hybrids will not be considered. The level of the component's models is appropriate for the conceptual design stage. They are simple and adaptable, so that a wide range of designs with morphologically different propulsive system architectures can be quickly compared. Modelling strategies for both mass and efficiency of each part of the propulsion system (engine, motor, battery and propeller) will be presented.}, language = {en} } @inproceedings{QuitterMarinoBauschat2019, author = {Quitter, Julius and Marino, Matthew and Bauschat, J.-Michael}, title = {Highly Non-Planar Aircraft Configurations: Estimation of Flight Mechanical Derivatives Using Low-Order Methods}, series = {Deutscher Luft- und Raumfahrtkongress 2019, DLRK 2019. Darmstadt, Germany}, booktitle = {Deutscher Luft- und Raumfahrtkongress 2019, DLRK 2019. Darmstadt, Germany}, pages = {10 Seiten}, year = {2019}, language = {en} } @inproceedings{ElgamalHeuermann2020, author = {Elgamal, Abdelrahman and Heuermann, Holger}, title = {Design and Development of a Hot S-Parameter Measurement System for Plasma and Magnetron Applications}, series = {2020 German Microwave Conference (GeMiC), Cottbus, Germany, 2020}, booktitle = {2020 German Microwave Conference (GeMiC), Cottbus, Germany, 2020}, isbn = {978-3-9820397-1-8}, pages = {124 -- 127}, year = {2020}, language = {en} } @inproceedings{FunkeBeckmannAbanteriba2017, author = {Funke, Harald and Beckmann, Nils and Abanteriba, Sylvester}, title = {A comparison of complex chemistry mechanisms for hydrogen methane blends based on the Sandia / Sydney Bluff-Body Flame HM1}, series = {Proceedings of the Eleventh Asia-Pacific Conference on Combustion (ASPACC 2017), New South Wales, Australia, 10-14 December 2017}, booktitle = {Proceedings of the Eleventh Asia-Pacific Conference on Combustion (ASPACC 2017), New South Wales, Australia, 10-14 December 2017}, isbn = {978-1-5108-5646-2}, pages = {262 -- 265}, year = {2017}, language = {en} } @inproceedings{FunkeBeckmannAbanteriba2019, author = {Funke, Harald and Beckmann, Nils and Abanteriba, Sylvester}, title = {Development and Testing of a FuelFlex Dry-Low-NOx Micromix Combustor for Industrial Gas Turbine Applications With Variable Hydrogen Methane Mixtures}, series = {ASME Turbo Expo 2019: Turbomachinery Technical Conference and Exposition. June 17-21, 2019 Phoenix, Arizona, USA. Volume 4A: Combustion, Fuels, and Emissions}, booktitle = {ASME Turbo Expo 2019: Turbomachinery Technical Conference and Exposition. June 17-21, 2019 Phoenix, Arizona, USA. Volume 4A: Combustion, Fuels, and Emissions}, isbn = {978-0-7918-5861-5}, doi = {10.1115/GT2019-90095}, pages = {11 Seiten}, year = {2019}, language = {en} } @inproceedings{HorikawaOkadaUtoetal.2019, author = {Horikawa, Atsushi and Okada, Kunio and Uto, Takahiro and Uchiyama, Yuta and Wirsum, Manfred and Funke, Harald and Kusterer, Karsten}, title = {Application of Low NOx Micro-mix Hydrogen Combustion to 2MW Class Industrial Gas Turbine Combustor}, series = {Proceedings of International Gas Turbine Congress 2019 Tokyo, November 17-22, 2019, Tokyo, Japan}, booktitle = {Proceedings of International Gas Turbine Congress 2019 Tokyo, November 17-22, 2019, Tokyo, Japan}, isbn = {978-4-89111-010-9}, pages = {1 -- 6}, year = {2019}, language = {en} } @inproceedings{FunkeBeckmann2019, author = {Funke, Harald and Beckmann, Nils}, title = {Flexible Fuel Operation of a Dry-Low-Nox Micromix Combustor with Variable Hydrogen Methane Mixtures}, series = {Proceedings of International Gas Turbine Congress 2019 Tokyo, November 17-22, 2019, Tokyo, Japan}, booktitle = {Proceedings of International Gas Turbine Congress 2019 Tokyo, November 17-22, 2019, Tokyo, Japan}, isbn = {978-4-89111-010-9}, year = {2019}, language = {en} } @inproceedings{StrieganStruthDickhoffetal.2019, author = {Striegan, Constantin J. D. and Struth, Benjamin and Dickhoff, Jens and Kusterer, Karsten and Funke, Harald and Bohn, Dieter}, title = {Numerical Simulations of the Micromix DLN Hydrogen Combustion Technology with LES and Comparison to Results of RANS and Experimental Data}, series = {Proceedings of International Gas Turbine Congress 2019 Tokyo, November 17-22, 2019, Tokyo, Japan.}, booktitle = {Proceedings of International Gas Turbine Congress 2019 Tokyo, November 17-22, 2019, Tokyo, Japan.}, isbn = {978-4-89111-010-9}, pages = {1 -- 9}, year = {2019}, language = {en} } @inproceedings{GerhardsSchleserOttenetal.2019, author = {Gerhards, Benjamin and Schleser, Markus and Otten,, Christian and Schwarz, Alexander and Gebhardt, Andreas}, title = {Innovative Laser Beam Joining Technology for Additive Manufactured Parts}, series = {Conference Proceedings 72nd IIW Annual Assembly and International Conference, 7-12 July 2019, Bratislava}, booktitle = {Conference Proceedings 72nd IIW Annual Assembly and International Conference, 7-12 July 2019, Bratislava}, pages = {1 -- 8}, year = {2019}, language = {en} } @inproceedings{GerhardsSchleserOtten2019, author = {Gerhards, Benjamin and Schleser, Markus and Otten, Christian}, title = {Advancements of mobile vacuum laser welding for industrial thick sheet applications}, series = {Conference Proceedings 72nd IIW Annual Assembly and International Conference, 7-12 July 2019, Bratislava}, booktitle = {Conference Proceedings 72nd IIW Annual Assembly and International Conference, 7-12 July 2019, Bratislava}, pages = {1 -- 8}, year = {2019}, language = {en} } @inproceedings{ValeroKramerBungetal.2019, author = {Valero, Daniel and Kramer, Matthias and Bung, Daniel B. and Chanson, Hubert}, title = {A stochastic bubble generator for air-water flow research}, series = {E-proceedings of the 38th IAHR World Congress, September 1-6, 2019, Panama City, Panama}, booktitle = {E-proceedings of the 38th IAHR World Congress, September 1-6, 2019, Panama City, Panama}, doi = {10.3850/38WC092019-0909}, pages = {5714 -- 5721}, year = {2019}, language = {en} } @inproceedings{TullisCrookstonBung2019, author = {Tullis, Blake P. and Crookston, Brian M. and Bung, Daniel B.}, title = {Weir head-discharge relationships: A multi-lab exercise}, series = {E-proceedings of the 38th IAHR World Congress September 1-6, 2019, Panama City, Panama}, booktitle = {E-proceedings of the 38th IAHR World Congress September 1-6, 2019, Panama City, Panama}, pages = {1 -- 15}, year = {2019}, language = {en} } @inproceedings{BungOertel2019, author = {Bung, Daniel B. and Oertel, Mario}, title = {Wave breaking over a submerged horizontal plate: Optical Flow, LES and RANS}, series = {E-proceedings of the 38th IAHR World Congress September 1-6, 2019, Panama City, Panama}, booktitle = {E-proceedings of the 38th IAHR World Congress September 1-6, 2019, Panama City, Panama}, doi = {10.3850/38WC092019-0509}, pages = {3690 -- 3698}, year = {2019}, language = {en} } @inproceedings{BraunChengLaietal.2019, author = {Braun, Sebastian and Cheng, Chi-Tsun and Lai, Chow Yin and Wollert, J{\"o}rg}, title = {Microservice Architecture for Automation - Realization by the example of a model-factory's manufacturing execution system}, series = {Proceedings of the 23rd World Multi-Conference on Systemics, Cybernetics and Informatics: WMSCI 2019}, booktitle = {Proceedings of the 23rd World Multi-Conference on Systemics, Cybernetics and Informatics: WMSCI 2019}, pages = {33 -- 37}, year = {2019}, language = {en} } @inproceedings{OttenSchmidtWeber2016, author = {Otten, D. and Schmidt, M. and Weber, Tobias}, title = {Advances in Determination of Material Parameters for Functional Simulations Based on Process Simulations}, series = {SAMPE Europe Conference 16 Liege}, booktitle = {SAMPE Europe Conference 16 Liege}, isbn = {978-1-5108-3800-0}, pages = {570 -- 577}, year = {2016}, language = {en} } @inproceedings{WeberTellisDuhovic2016, author = {Weber, Tobias and Tellis, Jane J. and Duhovic, Miro}, title = {Characterization of tool-part-interaction an interlaminar friction for manufacturing process simulation}, series = {ECCM 17, 17th European Conference on Composite Materials, M{\"u}nchen, DE, Jun 26-30, 2016}, booktitle = {ECCM 17, 17th European Conference on Composite Materials, M{\"u}nchen, DE, Jun 26-30, 2016}, isbn = {978-3-00-053387-7}, pages = {1 -- 7}, year = {2016}, language = {en} } @inproceedings{ElMoussaouiKassmiAlexopoulosetal.2021, author = {El Moussaoui, Noureddine and Kassmi, Khalil and Alexopoulos, Spiros and Schwarzer, Klemens and Chayeb, Hamid and Bachiri, Najib}, title = {Simulation studies on a new innovative design of a hybrid solar distiller MSDH alimented with a thermal and photovoltaic energy}, series = {Materialstoday: Proceedings}, booktitle = {Materialstoday: Proceedings}, issn = {2214-7853}, doi = {10.1016/j.matpr.2021.03.115}, year = {2021}, language = {en} } @inproceedings{FerreinMeessenLimpertetal.2021, author = {Ferrein, Alexander and Meeßen, Marcus and Limpert, Nicolas and Schiffer, Stefan}, title = {Compiling ROS Schooling Curricula via Contentual Taxonomies}, series = {Robotics in Education}, booktitle = {Robotics in Education}, editor = {Lepuschitz, Wilfried}, publisher = {Springer}, address = {Cham}, isbn = {978-3-030-67411-3}, doi = {10.1007/978-3-030-67411-3_5}, pages = {49 -- 60}, year = {2021}, language = {en} } @inproceedings{MistlerButenwegAnthoine2004, author = {Mistler, M. and Butenweg, Christoph and Anthoine, A.}, title = {Evaluation of the failure criterion for masonry by homogenisation}, series = {Proceedings of the Seventh International Conference on Computational Structures Technology : [Lisbon, Portugal, 7 - 9 September 2004] / ed. by B. H. V. Topping and C.A. Mota Soares}, booktitle = {Proceedings of the Seventh International Conference on Computational Structures Technology : [Lisbon, Portugal, 7 - 9 September 2004] / ed. by B. H. V. Topping and C.A. Mota Soares}, publisher = {Civil-Comp Press}, address = {Stirling}, organization = {International Conference on Computational Structures Technology <7, 2004, Lissabon>}, isbn = {0-948749-95-4}, doi = {10.4203/ccp.79.201}, pages = {16 Seiten}, year = {2004}, language = {en} } @inproceedings{HeuermannHarzheimMuehmel2021, author = {Heuermann, Holger and Harzheim, Thomas and M{\"u}hmel, Marc}, title = {A maritime harmonic radar search and rescue system using passive and active tags}, series = {2020 17th European Radar Conference (EuRAD)}, booktitle = {2020 17th European Radar Conference (EuRAD)}, publisher = {IEEE}, isbn = {978-2-87487-061-3}, doi = {10.1109/EuRAD48048.2021.00030}, pages = {73 -- 76}, year = {2021}, language = {en} } @inproceedings{AyedStrieganKustereretal.2017, author = {Ayed, Anis Haj and Striegan, Constantin J. D. and Kusterer, Karsten and Funke, Harald and Kazari, M. and Horikawa, Atsushi and Okada, Kunio}, title = {Automated design space exploration of the hydrogen fueled "Micromix" combustor technology}, pages = {1 -- 8}, year = {2017}, abstract = {Combined with the use of renewable energy sources for its production, Hydrogen represents a possible alternative gas turbine fuel for future low emission power generation. Due to its different physical properties compared to other fuels such as natural gas, well established gas turbine combustion systems cannot be directly applied for Dry Low NOx (DLN) Hydrogen combustion. This makes the development of new combustion technologies an essential and challenging task for the future of hydrogen fueled gas turbines. The newly developed and successfully tested "DLN Micromix" combustion technology offers a great potential to burn hydrogen in gas turbines at very low NOx emissions. Aiming to further develop an existing burner design in terms of increased energy density, a redesign is required in order to stabilise the flames at higher mass flows and to maintain low emission levels. For this purpose, a systematic design exploration has been carried out with the support of CFD and optimisation tools to identify the interactions of geometrical and design parameters on the combustor performance. Aerodynamic effects as well as flame and emission formation are observed and understood time- and cost-efficiently. Correlations between single geometric values, the pressure drop of the burner and NOx production have been identified as a result. This numeric methodology helps to reduce the effort of manufacturing and testing to few designs for single validation campaigns, in order to confirm the flame stability and NOx emissions in a wider operating condition field.}, language = {en} } @inproceedings{FunkeBeckmannKeinzetal.2021, author = {Funke, Harald and Beckmann, Nils and Keinz, Jan and Horikawa, Atsushi}, title = {30 years of dry low NOx micromix combustor research for hydrogen-rich fuels: an overview of past and present activities}, series = {Proceedings of the ASME Turbo Expo 2020: Turbomachinery Technical Conference and Exposition, September 21-25, 2020, Virtual, Online. Vol.: 4B: Combustion, Fuels, and Emissions}, booktitle = {Proceedings of the ASME Turbo Expo 2020: Turbomachinery Technical Conference and Exposition, September 21-25, 2020, Virtual, Online. Vol.: 4B: Combustion, Fuels, and Emissions}, publisher = {American Society of Mechanical Engineers (ASME)}, isbn = {978-0-7918-8413-3}, doi = {10.1115/GT2020-16328}, pages = {14 Seiten}, year = {2021}, language = {en} } @inproceedings{SchulteEggert2021, author = {Schulte, Maximilian and Eggert, Mathias}, title = {Predicting hourly bitcoin prices based on long short-term memory neural networks}, series = {Proceedings of the International Conference on Wirtschaftsinformatik (WI) 2021}, booktitle = {Proceedings of the International Conference on Wirtschaftsinformatik (WI) 2021}, pages = {16 Seiten}, year = {2021}, abstract = {Bitcoin is a cryptocurrency and is considered a high-risk asset class whose price changes are difficult to predict. Current research focusses on daily price movements with a limited number of predictors. The paper at hand aims at identifying measurable indicators for Bitcoin price movement s and the development of a suitable forecasting model for hourly changes. The paper provides three research contributions. First, a set of significant indicators for predicting the Bitcoin price is identified. Second, the results of a trained Long Short-term Memory (LSTM) neural network that predicts price changes on an hourly basis is presented and compared with other algorithms. Third, the results foster discussions of the applicability of neural nets for stock price predictions. In total, 47 input features for a period of over 10 months could be retrieved to train a neural net that predicts the Bitcoin price movements with an error rate of 3.52 \%.}, language = {en} } @inproceedings{BergmannGraebenerWildetal.2019, author = {Bergmann, Kevin and Gr{\"a}bener, Josefine and Wild, Dominik and Ulfers, H. and Czupalla, Markus}, title = {Study on thermal stabilization of a GEO-stationary telescope baffling system by integral application of phase change material}, series = {International Conference on Environmental Systems}, booktitle = {International Conference on Environmental Systems}, pages = {1 -- 14}, year = {2019}, abstract = {The utilization of phase change material (PCM) for latent heat storage and thermal control of spacecraft has been demonstrated in the past in few missions only. One limiting factor was the fact that all concepts developed so far envisioned the PCM to be applied as an additional capacitor, encapsulated in its own housing, leading to mass, efficiency and accommodation challenges. Recently, the application of PCM within the scan cavity of a GEOS type satellite has been suggested, in order to tackle thermal issues due to direct sun intrusion (Choi, M., 2014). However, the application of PCM in such complex mechanical structures is extremely challenging. A new concept to tackle this issue is currently under development at the FH Aachen University of Applied Sciences. The concept "Infused Thermal Solutions (ITS)" is based on the idea to 3D print metallic structures in their regular functional shape, but double walled with internal lattice support structures, allowing the infusion of a PCM layer directly into the voids and eliminating the need for additional parts and interfaces. Together with OHB System, FH Aachen theoretically studied the application of this technology to the Meteosat Third Generation (MTG) Infra-Red Sounder (IRS) instrument. The study focuses on the scan cavity and entrance baffling assembly (EBA) of the IRS. It consists of thermal analyses, 3D-redesign and bread boarding of a scaled and PCM infused EBA version. In the thermal design of the alternative EBA, PCM was applied directly into the EBA, simulating the worst hot case sun intrusion of the mission. By applying 4kg of PCM (to a 60kg baffle) the EBA temperature excursions during sun intrusion were limited from 140K to 30K, leading to a significant thermo-opto-elastic performance gain. This paper introduces the ITS concept development status.}, language = {en} } @inproceedings{SattlerCaminosUerlingsetal.2020, author = {Sattler, Johannes, Christoph and Caminos, Ricardo Alexander Chico and {\"U}rlings, Nicolas and Dutta, Siddharth and Ruiz, Victor and Kalogirou, Soteris and Ktistis, Panayiotis and Agathokleous, Rafaela and Jung, Christian and Alexopoulos, Spiros and Atti, Vikrama Nagababu and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf}, title = {Operational experience and behaviour of a parabolic trough collector system with concrete thermal energy storage for process steam generation in Cyprus}, series = {AIP Conference Proceedings}, booktitle = {AIP Conference Proceedings}, number = {2303}, doi = {10.1063/5.0029278}, pages = {140004-1 -- 140004-10}, year = {2020}, 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} } @inproceedings{AdamsLosekammCzupalla2020, author = {Adams, Moritz and Losekamm, Martin J. and Czupalla, Markus}, title = {Development of the Thermal Control System for the RadMap Telescope Experiment on the International Space Station}, series = {International Conference on Environmental Systems}, booktitle = {International Conference on Environmental Systems}, pages = {1 -- 10}, year = {2020}, language = {en} } @inproceedings{ThomaFisherBertrandetal.2020, author = {Thoma, Andreas and Fisher, Alex and Bertrand, Olivier and Braun, Carsten}, title = {Evaluation of possible flight strategies for close object evasion from bumblebee experiments}, series = {Living Machines 2020: Biomimetic and Biohybrid Systems}, booktitle = {Living Machines 2020: Biomimetic and Biohybrid Systems}, editor = {Vouloutsi, Vasiliki and Mura, Anna and Tauber, Falk and Speck, Thomas and Prescott, Tony J. and Verschure, Paul F. M. J.}, publisher = {Springer}, address = {Cham}, isbn = {978-3-030-64312-6}, doi = {10.1007/978-3-030-64313-3_34}, pages = {354 -- 365}, year = {2020}, language = {en} } @inproceedings{OhndorfDachwaldSeboldtetal.2011, author = {Ohndorf, Andreas and Dachwald, Bernd and Seboldt, Wolfgang and Schartner, Karl-Heinz}, title = {Flight times to the heliopause using a combination of solar and radioisotope electric propulsion}, series = {32nd International Electric Propulsion Conference}, booktitle = {32nd International Electric Propulsion Conference}, pages = {1 -- 12}, year = {2011}, abstract = {We investigate the interplanetary flight of a low-thrust space probe to the heliopause,located at a distance of about 200 AU from the Sun. Our goal was to reach this distance within the 25 years postulated by ESA for such a mission (which is less ambitious than the 15-year goal set by NASA). Contrary to solar sail concepts and combinations of allistic and electrically propelled flight legs, we have investigated whether the set flight time limit could also be kept with a combination of solar-electric propulsion and a second, RTG-powered upper stage. The used ion engine type was the RIT-22 for the first stage and the RIT-10 for the second stage. Trajectory optimization was carried out with the low-thrust optimization program InTrance, which implements the method of Evolutionary Neurocontrol,using Artificial Neural Networks for spacecraft steering and Evolutionary Algorithms to optimize the Neural Networks' parameter set. Based on a parameter space study, in which the number of thrust units, the unit's specific impulse, and the relative size of the solar power generator were varied, we have chosen one configuration as reference. The transfer time of this reference configuration was 29.6 years and the fastest one, which is technically more challenging, still required 28.3 years. As all flight times of this parameter study were longer than 25 years, we further shortened the transfer time by applying a launcher-provided hyperbolic excess energy up to 49 km2/s2. The resulting minimal flight time for the reference configuration was then 27.8 years. The following, more precise optimization to a launch with the European Ariane 5 ECA rocket reduced the transfer time to 27.5 years. This is the fastest mission design of our study that is flexible enough to allow a launch every year. The inclusion of a fly-by at Jupiter finally resulted in a flight time of 23.8 years,which is below the set transfer-time limit. However, compared to the 27.5-year transfer,this mission design has a significantly reduced launch window and mission flexibility if the escape direction is restricted to the heliosphere's "nose".}, language = {en} } @inproceedings{SchmidtKaschEichleretal.2021, author = {Schmidt, Thomas and Kasch, Susanne and Eichler, Fabian and Thurn, Laura}, title = {Process strategies on laser-based melting of glass powder}, series = {Lasers in Manufacturing Conference 2021}, booktitle = {Lasers in Manufacturing Conference 2021}, pages = {10 Seiten}, year = {2021}, abstract = {This paper presents the laser-based powder bed fusion (L-PBF) using various glass powders (borosilicate and quartz glass). Compared to metals, these require adapted process strategies. First, the glass powders were characterized with regard to their material properties and their processability in the powder bed. This was followed by investigations of the melting behavior of the glass powders with different laser wavelengths (10.6 µm, 1070 nm). In particular, the experimental setup of a CO2 laser was adapted for the processing of glass powder. An experimental setup with integrated coaxial temperature measurement/control and an inductively heatable build platform was created. This allowed the L-PBF process to be carried out at the transformation temperature of the glasses. Furthermore, the component's material quality was analyzed on three-dimensional test specimen with regard to porosity, roughness, density and geometrical accuracy in order to evaluate the developed L-PBF parameters and to open up possible applications.}, language = {en} } @inproceedings{BorggraefeDachwald2010, author = {Borggr{\"a}fe, Andreas and Dachwald, Bernd}, title = {Mission performance evaluation for solar sails using a refined SRP force model with variable optical coefficients}, series = {2nd International Symposium on Solar Sailing}, booktitle = {2nd International Symposium on Solar Sailing}, pages = {1 -- 6}, year = {2010}, abstract = {Solar sails provide ignificant advantages over other low-thrust propulsion systems because they produce thrust by the momentum exchange from solar radiation pressure (SRP) and thus do not consume any propellant.The force exerted on a very thin sail foil basically depends on the light incidence angle. Several analytical SRP force models that describe the SRP force acting on the sail have been established since the 1970s. All the widely used models use constant optical force coefficients of the reflecting sail material. In 2006,MENGALI et al. proposed a refined SRP force model that takes into account the dependancy of the force coefficients on the light incident angle,the sail's distance from the sun (and thus the sail emperature) and the surface roughness of the sail material [1]. In this paper, the refined SRP force model is compared to the previous ones in order to identify the potential impact of the new model on the predicted capabilities of solar sails in performing low-cost interplanetary space missions. All force models have been implemented within InTrance, a global low-thrust trajectory optimization software utilizing evolutionary neurocontrol [2]. Two interplanetary rendezvous missions, to Mercury and the near-Earth asteroid 1996FG3, are investigated. Two solar sail performances in terms of characteristic acceleration are examined for both scenarios, 0.2 mm/s2 and 0.5 mm/s2, termed "low" and "medium" sail performance. In case of the refined SRP model, three different values of surface roughness are chosen, h = 0 nm, 10 nm and 25 nm. The results show that the refined SRP force model yields shorter transfer times than the standard model.}, language = {en} } @inproceedings{KronigerHorikawaFunkeetal.2021, author = {Kroniger, Daniel and Horikawa, Atsushi and Funke, Harald and Pf{\"a}ffle, Franziska and Kishimoto, Tsuyoshi and Okada, Koichi}, title = {Experimental and numerical investigation on the effect of pressure on micromix hydrogen combustion}, series = {ASME Turbo Expo 2021: Turbomachinery Technical Conference and Exposition // Volume 3A: Combustion, Fuels, and Emissions}, booktitle = {ASME Turbo Expo 2021: Turbomachinery Technical Conference and Exposition // Volume 3A: Combustion, Fuels, and Emissions}, doi = {10.1115/GT2021-58926}, pages = {11 Seiten}, year = {2021}, abstract = {The micromix (MMX) combustion concept is a DLN gas turbine combustion technology designed for high hydrogen content fuels. Multiple non-premixed miniaturized flames based on jet in cross-flow (JICF) are inherently safe against flashback and ensure a stable operation in various operative conditions. The objective of this paper is to investigate the influence of pressure on the micromix flame with focus on the flame initiation point and the NOx emissions. A numerical model based on a steady RANS approach and the Complex Chemistry model with relevant reactions of the GRI 3.0 mechanism is used to predict the reactive flow and NOx emissions at various pressure conditions. Regarding the turbulence-chemical interaction, the Laminar Flame Concept (LFC) and the Eddy Dissipation Concept (EDC) are compared. The numerical results are validated against experimental results that have been acquired at a high pressure test facility for industrial can-type gas turbine combustors with regard to flame initiation and NOx emissions. The numerical approach is adequate to predict the flame initiation point and NOx emission trends. Interestingly, the flame shifts its initiation point during the pressure increase in upstream direction, whereby the flame attachment shifts from anchoring behind a downstream located bluff body towards anchoring directly at the hydrogen jet. The LFC predicts this change and the NOx emissions more accurately than the EDC. The resulting NOx correlation regarding the pressure is similar to a non-premixed type combustion configuration.}, language = {en} } @inproceedings{HandschuhStollenwerkBorchert2021, author = {Handschuh, Nils and Stollenwerk, Dominik and Borchert, J{\"o}rg}, title = {Operation of thermal storage power plants under high renewable grid penetration}, series = {NEIS 2021: Conference on Sustainable Energy Supply and Energy Storage Systems}, booktitle = {NEIS 2021: Conference on Sustainable Energy Supply and Energy Storage Systems}, publisher = {VDE Verlag}, address = {Berlin}, isbn = {978-3-8007-5651-3}, pages = {261 -- 265}, year = {2021}, abstract = {The planned coal phase-out in Germany by 2038 will lead to the dismantling of power plants with a total capacity of approx. 30 GW. A possible further use of these assets is the conversion of the power plants to thermal storage power plants; the use of these power plants on the day-ahead market is considerably limited by their technical parameters. In this paper, the influence of the technical boundary conditions on the operating times of these storage facilities is presented. For this purpose, the storage power plants were described as an MILP problem and two price curves, one from 2015 with a relatively low renewable penetration (33 \%) and one from 2020 with a high renewable energy penetration (51 \%) are compared. The operating times were examined as a function of the technical parameters and the critical influencing factors were investigated. The thermal storage power plant operation duration and the energy shifted with the price curve of 2020 increases by more than 25 \% compared to 2015.}, 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{GrundmannBodenCeriottietal.2017, author = {Grundmann, Jan Thimo and Boden, Ralf and Ceriotti, Matteo and Dachwald, Bernd and Dumont, Etienne and Grimm, Christian D. and Lange, Caroline and Lichtenheldt, Roy and Pelivan, Ivanka and Peloni, Alessandro and Riemann, Johannes and Spr{\"o}witz, Tom and Tardivel, Simon}, title = {Soil to sail-asteroid landers on near-term sailcraft as an evolution of the GOSSAMER small spacecraft solar sail concept for in-situ characterization}, series = {5th IAA Planetary Defense Conference}, booktitle = {5th IAA Planetary Defense Conference}, pages = {30 Seiten}, year = {2017}, language = {en} } @inproceedings{SeboldtDachwald2003, author = {Seboldt, Wolfgang and Dachwald, Bernd}, title = {Solar sails for near-term advanced scientific deep space missions}, series = {Proceedings of the 8th International Workshop on Combustion and Propulsion}, booktitle = {Proceedings of the 8th International Workshop on Combustion and Propulsion}, pages = {14 Seiten}, year = {2003}, abstract = {Solar sails are propelled in space by reflecting solar photons off large mirroring surfaces, thereby transforming the momentum of the photons into a propulsive force. This innovative concept for low-thrust space propulsion works without any propellant and thus provides a wide range of opportunities for highenergy low-cost missions. Offering an efficient way of propulsion, solar sailcraft could close a gap in transportation options for highly demanding exploration missions within our solar system and even beyond. On December 17th, 1999, a significant step was made towards the realization of this technology: a lightweight solar sail structure with an area of 20 m × 20 m was successfully deployed on ground in a large facility at the German Aerospace Center (DLR) at Cologne. The deployment from a package of 60 cm × 60 cm × 65 cm with a total mass of less than 35 kg was achieved using four extremely light-weight carbon fiber reinforced plastics (CFRP) booms with a specific mass of 100 g/m. The paper briefly reviews the basic principles of solar sails as well as the technical concept and its realization in the ground demonstration experiment, performed in close cooperation between DLR and ESA. Next possible steps are outlined. They could comprise the in-orbit demonstration of the sail deployment on the upper stage of a low-cost rocket and the verification of the propulsion concept by an autonomous and free flying solar sail in the frame of a scientific mission. It is expected that the present design could be extended to sail sizes of about (40 m)2 up to even (70 m)2 without significant mass penalty. With these areas, the maximum achievable thrust at 1 AU would range between 10 and 40 mN - comparable to some electric thrusters. Such prototype sails with a mass between 50 and 150 kg plus a micro-spacecraft of 50 to 250 kg would have a maximum acceleration in the order of 0.1 mm/s2 at 1 AU, corresponding to a maximum ∆V-capability of about 3 km/s per year. Two near/medium-term mission examples to a near-Earth asteroid (NEA) will be discussed: a rendezvous mission and a sample return mission.}, language = {en} } @inproceedings{DachwaldSeboldtHaeusler2002, author = {Dachwald, Bernd and Seboldt, Wolfgang and H{\"a}usler, Bernd}, title = {Performance requirements for near-term interplanetary solar sailcraft missions}, series = {6th International AAAF Symposium on Space Propulsion: Propulsion for Space Transportation of the XXIst Century}, booktitle = {6th International AAAF Symposium on Space Propulsion: Propulsion for Space Transportation of the XXIst Century}, pages = {9 Seiten}, year = {2002}, abstract = {Solar sailcraft provide a wide range of opportunities for high-energy low-cost missions. To date, most mission studies require a rather demanding performance that will not be realized by solar sailcraft of the first generation. However, even with solar sailcraft of moderate performance, scientifically relevant missions are feasible. This is demonstrated with a Near Earth Asteroid sample return mission and various planetary rendezvous missions.}, language = {en} } @inproceedings{SchartnerLoebDachwaldetal.2009, author = {Schartner, Karl-Heinz and Loeb, H. W. and Dachwald, Bernd and Ohndorf, Andreas}, title = {Perspectives of electric propulsion for outer planetary and deep space missions}, series = {European Planetary Science Congress 2009}, booktitle = {European Planetary Science Congress 2009}, pages = {416 -- 416}, year = {2009}, abstract = {Solar-electric propulsion (SEP) is superior with respect to payload capacity, flight time and flexible launch window to the conventional interplanetary transfer method using chemical propulsion combined with gravity assists. This fact results from the large exhaust velocities of electric low-thrust propulsion and is favourable also for missions to the giant planets, Kuiper-belt objects and even for a heliopause probe (IHP) as shown in three studies by the authors funded by DLR. They dealt with a lander for Europa and a sample return mission from a mainbelt asteroid [1], with the TANDEM mission [2]; the third recent one investigates electric propulsion for the transfer to the edge of the solar system. All studies are based on triple-junction solar arrays, on rf-ion thrusters of the qualified RIT-22 type and they use the intelligent trajectory optimization program InTrance [3].}, language = {en} } @inproceedings{SpurmannOhndorfDachwaldetal.2009, author = {Spurmann, J{\"o}rn and Ohndorf, Andreas and Dachwald, Bernd and Seboldt, Wolfgang and L{\"o}b, Horst and Schartner, Karl-Heinz}, title = {Interplanetary trajectory optimization for a sep mission to Saturn}, series = {60th International Astronautical Congress 2009}, booktitle = {60th International Astronautical Congress 2009}, isbn = {9781615679089}, pages = {5234 -- 5248}, year = {2009}, abstract = {The recently proposed NASA and ESA missions to Saturn and Jupiter pose difficult tasks to mission designers because chemical propulsion scenarios are not capable of transferring heavy spacecraft into the outer solar system without the use of gravity assists. Thus our developed mission scenario based on the joint NASA/ESA Titan Saturn System Mission baselines solar electric propulsion to improve mission flexibility and transfer time. For the calculation of near-globally optimal low-thrust trajectories, we have used a method called Evolutionary Neurocontrol, which is implemented in the low-thrust trajectory optimization software InTrance. The studied solar electric propulsion scenario covers trajectory optimization of the interplanetary transfer including variations of the spacecraft's thrust level, the thrust unit's specific impulse and the solar power generator power level. Additionally developed software extensions enabled trajectory optimization with launcher-provided hyperbolic excess energy, a complex solar power generator model and a variable specific impulse ion engine model. For the investigated mission scenario, Evolutionary Neurocontrol yields good optimization results, which also hold valid for the more elaborate spacecraft models. Compared to Cassini/Huygens, the best found solutions have faster transfer times and a higher mission flexibility in general.}, language = {en} }