@inproceedings{WarerkarSchmitzGoettscheetal.2008, author = {Warerkar, S. and Schmitz, S. and G{\"o}ttsche, Joachim and Hoffschmidt, Bernhard and Tamme, R.}, title = {Performance analysis of an air-sand heat exchanger prototype for high-temperature storage}, series = {EuroSun 2008 : 1st International Conference on Solar Heating, Cooling and Buildings ; 7th - 10th October 2008, Lisbon, Portugal : key lectures / ISES, International Solar Energy Society. Vol. 1}, booktitle = {EuroSun 2008 : 1st International Conference on Solar Heating, Cooling and Buildings ; 7th - 10th October 2008, Lisbon, Portugal : key lectures / ISES, International Solar Energy Society. Vol. 1}, publisher = {Sociedade Portuguesa De Energia Solar (SPES)}, address = {Lissabon}, isbn = {978-1-61782-228-5}, pages = {2215 -- 2222}, year = {2008}, language = {en} } @article{StaatVu2007, author = {Staat, Manfred and Vu, Duc-Khoi}, title = {Limit analysis of flaws in pressurized pipes and cylindrical vessels. Part I: Axial defects}, series = {Engineering Fracture Mechanics. 74 (2007), H. 3}, journal = {Engineering Fracture Mechanics. 74 (2007), H. 3}, isbn = {0013-7944}, pages = {431 -- 450}, year = {2007}, language = {en} } @article{CheenakulaHoffstadtKrafftetal.2022, author = {Cheenakula, Dheeraja and Hoffstadt, Kevin and Krafft, Simone and Reinecke, Diana and Klose, Holger and Kuperjans, Isabel and Gr{\"o}mping, Markus}, title = {Anaerobic digestion of algal-bacterial biomass of an Algal Turf Scrubber system}, series = {Biomass Conversion and Biorefinery}, volume = {13}, journal = {Biomass Conversion and Biorefinery}, publisher = {Springer}, address = {Berlin}, issn = {2190-6823}, doi = {10.1007/s13399-022-03236-z}, pages = {15 Seiten}, year = {2022}, abstract = {This study investigated the anaerobic digestion of an algal-bacterial biofilm grown in artificial wastewater in an Algal Turf Scrubber (ATS). The ATS system was located in a greenhouse (50°54′19ʺN, 6°24′55ʺE, Germany) and was exposed to seasonal conditions during the experiment period. The methane (CH4) potential of untreated algal-bacterial biofilm (UAB) and thermally pretreated biofilm (PAB) using different microbial inocula was determined by anaerobic batch fermentation. Methane productivity of UAB differed significantly between microbial inocula of digested wastepaper, a mixture of manure and maize silage, anaerobic sewage sludge, and percolated green waste. UAB using sewage sludge as inoculum showed the highest methane productivity. The share of methane in biogas was dependent on inoculum. Using PAB, a strong positive impact on methane productivity was identified for the digested wastepaper (116.4\%) and a mixture of manure and maize silage (107.4\%) inocula. By contrast, the methane yield was significantly reduced for the digested anaerobic sewage sludge (50.6\%) and percolated green waste (43.5\%) inocula. To further evaluate the potential of algal-bacterial biofilm for biogas production in wastewater treatment and biogas plants in a circular bioeconomy, scale-up calculations were conducted. It was found that a 0.116 km2 ATS would be required in an average municipal wastewater treatment plant which can be viewed as problematic in terms of space consumption. However, a substantial amount of energy surplus (4.7-12.5 MWh a-1) can be gained through the addition of algal-bacterial biomass to the anaerobic digester of a municipal wastewater treatment plant. Wastewater treatment and subsequent energy production through algae show dominancy over conventional technologies.}, language = {en} } @article{BornheimGriegerBlanecketal.2024, author = {Bornheim, Tobias and Grieger, Niklas and Blaneck, Patrick Gustav and Bialonski, Stephan}, title = {Speaker Attribution in German Parliamentary Debates with QLoRA-adapted Large Language Models}, series = {Journal for language technology and computational linguistics : JLCL}, volume = {37}, journal = {Journal for language technology and computational linguistics : JLCL}, number = {1}, publisher = {Gesellschaft f{\"u}r Sprachtechnologie und Computerlinguistik}, address = {Regensburg}, issn = {2190-6858}, doi = {10.21248/jlcl.37.2024.244}, pages = {13 Seiten}, year = {2024}, abstract = {The growing body of political texts opens up new opportunities for rich insights into political dynamics and ideologies but also increases the workload for manual analysis. Automated speaker attribution, which detects who said what to whom in a speech event and is closely related to semantic role labeling, is an important processing step for computational text analysis. We study the potential of the large language model family Llama 2 to automate speaker attribution in German parliamentary debates from 2017-2021. We fine-tune Llama 2 with QLoRA, an efficient training strategy, and observe our approach to achieve competitive performance in the GermEval 2023 Shared Task On Speaker Attribution in German News Articles and Parliamentary Debates. Our results shed light on the capabilities of large language models in automating speaker attribution, revealing a promising avenue for computational analysis of political discourse and the development of semantic role labeling systems.}, language = {en} } @inproceedings{SattlerAttiAlexopoulosetal.2022, author = {Sattler, Johannes Christoph and Atti, Vikrama and Alexopoulos, Spiros and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf and Dutta, Siddharth and Kioutsioukis, Ioannis}, title = {DNI forecast tool for the smart operation of a parabolic trough collector system with concrete thermal energy storage: Theory, results and outlook}, series = {SolarPACES 2022 conference proceedings}, booktitle = {SolarPACES 2022 conference proceedings}, number = {1}, publisher = {TIB Open Publishing}, address = {Hannover}, issn = {2751-9899 (online)}, doi = {10.52825/solarpaces.v1i.731}, pages = {9 Seiten}, year = {2022}, abstract = {This work presents a basic forecast tool for predicting direct normal irradiance (DNI) in hourly resolution, which the Solar-Institut J{\"u}lich (SIJ) is developing within a research project. The DNI forecast data shall be used for a parabolic trough collector (PTC) system with a concrete thermal energy storage (C-TES) located at the company KEAN Soft Drinks Ltd in Limassol, Cyprus. On a daily basis, 24-hour DNI prediction data in hourly resolution shall be automatically produced using free or very low-cost weather forecast data as input. The purpose of the DNI forecast tool is to automatically transfer the DNI forecast data on a daily basis to a main control unit (MCU). The MCU automatically makes a smart decision on the operation mode of the PTC system such as steam production mode and/or C-TES charging mode. The DNI forecast tool was evaluated using historical data of measured DNI from an on-site weather station, which was compared to the DNI forecast data. The DNI forecast tool was tested using data from 56 days between January and March 2022, which included days with a strong variation in DNI due to cloud passages. For the evaluation of the DNI forecast reliability, three categories were created and the forecast data was sorted accordingly. The result was that the DNI forecast tool has a reliability of 71.4 \% based on the tested days. The result fulfils SIJ's aim to achieve a reliability of around 70 \%, but SIJ aims to still improve the DNI forecast quality.}, language = {en} } @inproceedings{SattlerSchneiderAngeleetal.2022, author = {Sattler, Johannes Christoph and Schneider, Iesse Peer and Angele, Florian and Atti, Vikrama and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf}, title = {Development of heliostat field calibration methods: Theory and experimental test results}, series = {SolarPACES 2022 conference proceedings}, booktitle = {SolarPACES 2022 conference proceedings}, number = {1}, publisher = {TIB Open Publishing}, address = {Hannover}, issn = {2751-9899 (online)}, doi = {10.52825/solarpaces.v1i.678}, pages = {9 Seiten}, year = {2022}, abstract = {In this work, three patent pending calibration methods for heliostat fields of central receiver systems (CRS) developed by the Solar-Institut J{\"u}lich (SIJ) of the FH Aachen University of Applied Sciences are presented. The calibration methods can either operate in a combined mode or in stand-alone mode. The first calibration method, method A, foresees that a camera matrix is placed into the receiver plane where it is subjected to concentrated solar irradiance during a measurement process. The second calibration method, method B, uses an unmanned aerial vehicle (UAV) such as a quadrocopter to automatically fly into the reflected solar irradiance cross-section of one or more heliostats (two variants of method B were tested). The third calibration method, method C, foresees a stereo central camera or multiple stereo cameras installed e.g. on the solar tower whereby the orientations of the heliostats are calculated from the location detection of spherical red markers attached to the heliostats. The most accurate method is method A which has a mean accuracy of 0.17 mrad. The mean accuracy of method B variant 1 is 1.36 mrad and of variant 2 is 1.73 mrad. Method C has a mean accuracy of 15.07 mrad. For method B there is great potential regarding improving the measurement accuracy. For method C the collected data was not sufficient for determining whether or not there is potential for improving the accuracy.}, language = {en} } @inproceedings{GoemmelButenwegKob2007, author = {G{\"o}mmel, A. and Butenweg, Christoph and Kob, M.}, title = {A fluid-structure interaction model of vocal fold oscillation}, series = {5th International Workshop on Models and Analysis of Vocal Emissions for Biomedical Applications, MAVEBA 2007}, booktitle = {5th International Workshop on Models and Analysis of Vocal Emissions for Biomedical Applications, MAVEBA 2007}, isbn = {978-888453674-7}, pages = {127 -- 128}, year = {2007}, abstract = {Since fluid-structure interaction within the finite-element method is state of the art in many engineering fields, this method is used in voice analysis. A quasi two-dimensional model of the vocal folds including the ventricular folds is presented. First results of self-sustained vocal fold oscillation are presented and possibilities as well as limitations are discussed.}, language = {en} } @article{VantStaatBaroud2008, author = {Vant, Christianne and Staat, Manfred and Baroud, Gamal}, title = {Percutaneous Vertebroplasty: A Review of Two Intraoperative Complications}, series = {Bioengineering in Cell and Tissue Research / Artmann, Gerhard M. ; Chien, Shu (Eds.)}, journal = {Bioengineering in Cell and Tissue Research / Artmann, Gerhard M. ; Chien, Shu (Eds.)}, publisher = {Springer}, address = {Berlin}, isbn = {978-3-540-75408-4}, pages = {527 -- 539}, year = {2008}, language = {en} } @inproceedings{KruegerAnthrakidisFischeretal.2009, author = {Kr{\"u}ger, Dirk and Anthrakidis, Anette and Fischer, Stephan and Lokurlu, Ahmet and Walder, Markus and Croy, Reiner and Quaschning, Volker}, title = {Experiences with solar steam supply for an industrial steam network in the P3 Project}, series = {SolarPACES 2009 : electricity, fuels and clean water powered by the sun ; 15 - 18 September 2009, Berlin, Germany ; the 15th SolarPACES conference ; proceedings}, booktitle = {SolarPACES 2009 : electricity, fuels and clean water powered by the sun ; 15 - 18 September 2009, Berlin, Germany ; the 15th SolarPACES conference ; proceedings}, publisher = {Deutsches Zentrum f. Luft- u. Raumfahrt}, address = {Stuttgart}, isbn = {9783000287558}, pages = {1 CD-ROM}, year = {2009}, language = {en} } @article{VuStaat2007, author = {Vu, Duc Khoi and Staat, Manfred}, title = {Shakedown analysis of structures made of materials with temperature-dependent yield stress}, series = {International Journal of Solids and Structures. 44 (2007), H. 13}, journal = {International Journal of Solids and Structures. 44 (2007), H. 13}, isbn = {0020-7683}, pages = {4524 -- 4540}, year = {2007}, language = {en} } @incollection{KnottSofroniaGerressenetal.2014, author = {Knott, Thomas C. and Sofronia, Raluca E. and Gerressen, Marcus and Law, Yuen and Davidescu, Arjana and Savii, George G. and Gatzweiler, Karl-Heinz and Staat, Manfred and Kuhlen, Torsten W.}, title = {Preliminary bone sawing model for a virtual reality-based training simulator of bilateral sagittal split osteotomy}, series = {Biomedical simulation : 6th International Symposium, ISBMS 2014, Strasbourg, France, October 16-17, 2014 : proceedings (Lecture notes in computer science : vol. 8789)}, booktitle = {Biomedical simulation : 6th International Symposium, ISBMS 2014, Strasbourg, France, October 16-17, 2014 : proceedings (Lecture notes in computer science : vol. 8789)}, publisher = {Springer}, address = {Cham}, isbn = {978-3-319-12057-7 (Online)}, doi = {10.1007/978-3-319-12057-7_1}, pages = {1 -- 10}, year = {2014}, abstract = {Successful bone sawing requires a high level of skill and experience, which could be gained by the use of Virtual Reality-based simulators. A key aspect of these medical simulators is realistic force feedback. The aim of this paper is to model the bone sawing process in order to develop a valid training simulator for the bilateral sagittal split osteotomy, the most often applied corrective surgery in case of a malposition of the mandible. Bone samples from a human cadaveric mandible were tested using a designed experimental system. Image processing and statistical analysis were used for the selection of four models for the bone sawing process. The results revealed a polynomial dependency between the material removal rate and the applied force. Differences between the three segments of the osteotomy line and between the cortical and cancellous bone were highlighted.}, language = {en} } @inproceedings{GoettenFingerHavermannetal.2019, author = {G{\"o}tten, Falk and Finger, Felix and Havermann, Marc and Braun, Carsten and Marino, Matthew and Bil, Cees}, title = {A highly automated method for simulating airfoil characteristics at low Reynolds number using a RANS - transition approach}, series = {Deutscher Luft- und Raumfahrtkongress - DLRK 2019. Darmstadt, Germany}, booktitle = {Deutscher Luft- und Raumfahrtkongress - DLRK 2019. Darmstadt, Germany}, doi = {10.25967/490026}, pages = {1 -- 14}, year = {2019}, language = {en} } @article{WarerkarSchmitzGoettscheetal.2011, author = {Warerkar, Shashikant and Schmitz, Stefan and G{\"o}ttsche, Joachim and Hoffschmidt, Bernhard and Reißel, Martin and Tamme, Rainer}, title = {Air-Sand Heat Exchanger for High-Temperature Storage}, series = {Journal of Solar Energy Engineering. 133 (2011), H. 2}, journal = {Journal of Solar Energy Engineering. 133 (2011), H. 2}, publisher = {ASME}, address = {New York}, isbn = {0199-6231}, pages = {021010}, year = {2011}, language = {en} } @article{PhamVuTranetal.2010, author = {Pham, Phu Tinh and Vu, Khoi Duc and Tran, Thanh Ngoc and Staat, Manfred}, title = {A primal-dual algorithm for shakedown analysis of elastic-plastic bounded linearly kinematic hardening bodies}, pages = {1 -- 7}, year = {2010}, language = {en} } @article{AlhwarinFerreinScholl2014, author = {Alhwarin, Faraj and Ferrein, Alexander and Scholl, Ingrid}, title = {IR stereo kinect: improving depth images by combining structured light with IR stereo}, pages = {1 -- 9}, year = {2014}, language = {en} } @inproceedings{ThurnGebhardt2017, author = {Thurn, Laura and Gebhardt, Andreas}, title = {Arousing Enthusiasm for STEM: Teaching 3D Printing Technology}, series = {Conference Proceedings: New Perspectives in Science Education}, booktitle = {Conference Proceedings: New Perspectives in Science Education}, publisher = {liberiauniversitaria.it}, address = {Padua}, isbn = {978-88-6292-847-2}, pages = {87 -- 92}, year = {2017}, language = {en} } @inproceedings{BlankeSchmidtGoettscheetal.2022, author = {Blanke, Tobias and Schmidt, Katharina S. and G{\"o}ttsche, Joachim and D{\"o}ring, Bernd and Frisch, J{\´e}r{\^o}me and van Treeck, Christoph}, title = {Time series aggregation for energy system design: review and extension of modelling seasonal storages}, series = {Energy Informatics}, volume = {5}, booktitle = {Energy Informatics}, number = {1, Article number: 17}, editor = {Weidlich, Anke and Neumann, Dirk and Gust, Gunther and Staudt, Philipp and Sch{\"a}fer, Mirko}, publisher = {Springer Nature}, issn = {2520-8942}, doi = {10.1186/s42162-022-00208-5}, pages = {14 Seiten}, year = {2022}, abstract = {Using optimization to design a renewable energy system has become a computationally demanding task as the high temporal fluctuations of demand and supply arise within the considered time series. The aggregation of typical operation periods has become a popular method to reduce effort. These operation periods are modelled independently and cannot interact in most cases. Consequently, seasonal storage is not reproducible. This inability can lead to a significant error, especially for energy systems with a high share of fluctuating renewable energy. The previous paper, "Time series aggregation for energy system design: Modeling seasonal storage", has developed a seasonal storage model to address this issue. Simultaneously, the paper "Optimal design of multi-energy systems with seasonal storage" has developed a different approach. This paper aims to review these models and extend the first model. The extension is a mathematical reformulation to decrease the number of variables and constraints. Furthermore, it aims to reduce the calculation time while achieving the same results.}, language = {en} } @article{OertelBung2012, author = {Oertel, Mario and Bung, Daniel Bernhard}, title = {Initial stage of two-dimensional dam-break waves: laboratory versus VOF}, series = {Journal of hydraulic research}, volume = {50}, journal = {Journal of hydraulic research}, number = {1}, publisher = {Taylor \& Francis}, address = {London}, issn = {1814-2079 (E-Journal); 0022-1686 (Print)}, doi = {10.1080/00221686.2011.639981}, pages = {89 -- 97}, year = {2012}, abstract = {Since several decades, dam-break waves have been of main research interest. Mathematical approaches have been developed by analytical, physical and numerical models within the past 120 years. During the past 10 years, the number of research investigations has increased due to improved measurement techniques as well as significantly increased computer memories and performances. In this context, the present research deals with the initial stage of two-dimensional dam-break waves by comparing physical and numerical model results as well as analytical approaches. High-speed images and resulting particle image velocimetry calculations are thereby compared with the numerical volume-of-fluid (VOF) method, included in the commercial code FLOW-3D. Wave profiles and drag forces on placed obstacles are analysed in detail. Generally, a good agreement between the laboratory and VOF results is found.}, language = {en} } @article{HueningHeuermannWache2018, author = {H{\"u}ning, Felix and Heuermann, Holger and Wache, Franz-Josef}, title = {Wireless CAN without WLAN or Bluetooth}, series = {CAN Newsletter}, journal = {CAN Newsletter}, number = {December 2018}, pages = {44 -- 46}, year = {2018}, abstract = {In two developed concepts, dual-mode radio enables CAN participants to be integrated wirelessly into a CAN network. Constructed from a few components, a protocol-free, real-time transmission and thus transparent integration into CAN is provided.}, 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} }