@inbook{34210,
abstract = {{The application of the mechanical joining process clinching enables the joining of sheet metals with a wide range of material-thickness configurations, which is of interest in lightweight construction of multi-material structures. Each material-thickness combination results in a joint with its own property profile that is affected differently by variations. Manufacturing process-related effects from preforming steps influence the geometric shape of a clinched joint as well as its load-bearing capacity. During the clinching process high degrees of plastic strain, increased temperatures and high strain rates occur. In this context, a 3D numerical model was developed which can represent the material-specific behaviour during the process chain steps sheet metal forming, joining, and loading phase in order to achieve a high predictive accuracy of the simulation. Besides to the investigation of the prediction accuracy, the extent of the influence of individual modelling aspects such as temperature and strain rate dependency is examined.}},
author = {{Bielak, Christian Roman and Böhnke, Max and Bobbert, Mathias and Meschut, Gerson}},
booktitle = {{The Minerals, Metals & Materials Series}},
isbn = {{9783031062117}},
issn = {{2367-1181}},
publisher = {{Springer International Publishing}},
title = {{{Development of a Numerical 3D Model for Analyzing Clinched Joints in Versatile Process Chains}}},
doi = {{10.1007/978-3-031-06212-4_15}},
year = {{2022}},
}
@inproceedings{30265,
abstract = {{Due to increasing globalization and rising quality requirements, the steel and metal processing industry is facing growing cost and innovation pressure. Not least because of their high lightweight potential, high-strength steel materials are meeting the growing material requirements of steel and metal processing in areas such as aerospace and medical technology. In particular, the tight tolerance limits of applicable shape and dimensional accuracies pose a challenge in the processing of high-strength steel strip materials. Improving the processability of high-strength steel materials through the use of straighteners with set-up assistance systems significantly increases the potential for competing with other materials such as aluminum or magnesium alloys. }},
author = {{Bader, Fabian and Bathelt, Lukas and Djakow, Eugen and Henke, Christian and Homberg, Werner and Trächtler, Ansgar}},
location = {{Braga / Portugal}},
title = {{{An approach for an innovative 3d steel strip straightening machine for curvature and saber compensation}}},
doi = {{https://doi.org/10.4028/p-87wvu0}},
year = {{2022}},
}
@article{30962,
abstract = {{ Clinching as a mechanical joining process has become established in many areas of car body. In order to predict relevant properties of clinched joints and to ensure the reliability of the process, it is numerically simulated during the product development process. The prediction accuracy of the simulated process depends on the implemented friction model. Therefore, a new method for determining friction coefficients in sheet metal materials was developed and tested. The aim of this study is the numerical investigation of this experimental method by means of FE simulation. The experimental setup is modelled in a 3D numerical simulation taking into account the process parameters varying in the experiment, such as geometric properties, contact pressure and contact velocity. Furthermore, the contact description of the model is calibrated via the experimentally determined friction coefficients according to clinch-relevant parameter space. It is shown that the assumptions made in the determination of the experimental data in preliminary work are valid. In addition, it is investigated to what extent the standard Coulomb friction model in the FEM can reproduce the results of the experimental method. }},
author = {{Bielak, Christian Roman and Böhnke, Max and Bobbert, Mathias and Meschut, Gerson}},
issn = {{1464-4207}},
journal = {{Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications}},
keywords = {{Mechanical Engineering, General Materials Science}},
publisher = {{SAGE Publications}},
title = {{{Numerical investigation of a friction test to determine the friction coefficients for the clinching process}}},
doi = {{10.1177/14644207221093468}},
year = {{2022}},
}
@article{29951,
abstract = {{The components of a body in white consist of many individual thin-walled sheet metal parts, which usually are manufactured in deep-drawing processes. In general, the conditions in a deep-drawing process change due to changing tribology conditions, varying degrees of spring back, or scattering material properties in the sheet blanks, which affects the resulting pre-strain. Mechanical joining processes, especially clinching, are influenced by these process-related pre-strains. The final geometric shape of a clinched joint is affected to a significant level by the prior material deformation when joining with constant process parameters. That leads to a change in the stiffness and force transmission in the clinched joint due to the different geometric dimensions, such as interlock, neck thickness and bottom thickness, which directly affect the load bearing capacity. Here, the influence of the pre-straining in the deep drawing process on the force distribution in clinch points in an automotive assembly is investigated by finite-element models numerically. In further studies, the results are implemented in an optimization tool for designing clinched components. The methodology starts with a pre-straining of metal sheets. This step is followed by 2D rotationally symmetric forming simulations of the joining process. The resulting mesh of each forming simulation is rotated and 3D models are obtained. The clinched joint solid model with pre-strains is used further to determine the joint stiffnesses. With the simulation of the same test set-up with an equivalent point-connector model, the equivalent stiffness for each pre-strain combination is determined. Simulations are performed on a clinched component to assess the influence of pre-strain and sheet thinning on the clinched joint loadings by using the equivalent stiffnesses. The investigations clearly show that for the selected component, the loadings at the clinch points are dependent on the sheet thinning and the stiffnesses due to pre-strain. The magnitude of the influence varies depending on the quantity considered. For example, the shear force is more sensitive to the joint stiffness than to the sheet thinning.}},
author = {{Martin, Sven and Bielak, Christian Roman and Bobbert, Mathias and Tröster, Thomas and Meschut, Gerson}},
issn = {{0944-6524}},
journal = {{Production Engineering}},
keywords = {{Industrial and Manufacturing Engineering, Mechanical Engineering}},
publisher = {{Springer Science and Business Media LLC}},
title = {{{Numerical investigation of the clinched joint loadings considering the initial pre-strain in the joining area}}},
doi = {{10.1007/s11740-021-01103-w}},
year = {{2022}},
}
@inproceedings{29856,
author = {{Jamei, Said and Döller, Norbert and Lossau, Sebastian and Beule, Felix and Al Trjman, Mohamad and Aubel, Tobias and Meschut, Gerson and Sommer, Daniel and Facciotto, Silvio and Droste, Alexander and Haufe, Andre and Helbig, Martin and Gleich, Henning and Kose, Kim}},
booktitle = {{22. Kolloquium: Gemeinsame Forschung in der Klebtechnik}},
title = {{{DigiBody - Digitale Prozesskette zur Abbildung und Optimierung der Fügetechnik im Rohbau }}},
year = {{2022}},
}
@inproceedings{34293,
author = {{Wolters, Dennis and Engels, Gregor}},
booktitle = {{ICSOB'22 Companion Proceedings}},
publisher = {{CEUR}},
title = {{{Model-driven Design and Management of Professional Education Programmes}}},
volume = {{3316}},
year = {{2022}},
}
@inproceedings{32389,
author = {{Rossel, Moritz Sebastian and Meschut, Gerson}},
location = {{Toronto}},
title = {{{Increasing the Prediction Quality of Clinching Process Simulation with Extensible Die by Means of Friction Modeling as a Function of the Local Joining Process Parameters}}},
year = {{2022}},
}
@inbook{45605,
author = {{Freymuth, Nina}},
booktitle = {{Wissenschaftsläden in der Sozialen Arbeit. Partizipative Forschung und soziale Innovationen}},
editor = {{Benz, Benjamin and Schönig, Werner and Arp, Anna Liza and Lutz, Katharina and Offergeld, Jana}},
pages = {{13--14}},
publisher = {{Beltz Juventa}},
title = {{{Zum Einstieg: Master-Arbeit zu ökologischer und sozial gerechter Stadtplanung. Ein fiktives Beispiel}}},
year = {{2022}},
}
@article{35918,
author = {{Berger, Thomas and Dennstädt, Dario and Ilchmann, Achim and Worthmann, Karl}},
journal = {{SIAM Journal on Control and Optimization}},
number = {{6}},
pages = {{3358--3383}},
title = {{{Funnel MPC for nonlinear systems with relative degree one}}},
volume = {{60}},
year = {{2022}},
}
@article{45809,
abstract = {{AbstractTo summarize current knowledge and gaps regarding the role of postprandial glycaemic response in the paediatric population, a workshop was organized in June 2021 by the European branch of the International Life Science Institute (ILSI). This virtual event comprised of talks given by experts followed by in-depth discussions in breakout sessions with workshop participants. The main pre-specified topics addressed by the workshop organizing committee to the invited speakers and the workshop participants were: (1) the role of glycaemic responses for paediatric health, based on mechanistic insights from animal and human data, and long-term evidence from observational and intervention studies in paediatric populations, and (2) changes in metabolism and changes in dietary needs from infancy to adolescence. Each talk as well as the discussions were summarised, including the main identified research gaps. The workshop led to the consensus on the crucial role on health of postprandial glycaemic response in paediatric population. However, a lack of scientific data has been identified regarding detailed glucose and insulin profiles in response to foods commonly consumed by paediatric populations, as well as a lack of long-term evidence including the need for suitable predictors during childhood and adolescence to anticipate health effects during adulthood.
}},
author = {{Vinoy, Sophie and Goletzke, Janina and Rakhshandehroo, Maryam and Schweitzer, Lisa and Flourakis, Matthieu and Körner, Antje and Alexy, Ute and van Schothorst, Evert M. and Ceriello, Antonio and Zakrzewski-Fruer, Julia K. and Buyken, Anette}},
issn = {{1436-6207}},
journal = {{European Journal of Nutrition}},
keywords = {{Nutrition and Dietetics, Medicine (miscellaneous)}},
number = {{3}},
pages = {{1093--1107}},
publisher = {{Springer Science and Business Media LLC}},
title = {{{Health relevance of lowering postprandial glycaemia in the paediatric population through diet’: results from a multistakeholder workshop}}},
doi = {{10.1007/s00394-022-03047-y}},
volume = {{62}},
year = {{2022}},
}
@article{45808,
author = {{Schadow, Alena M. and Revheim, Ingrid and Spielau, Ulrike and Dierkes, Jutta and Schwingshackl, Lukas and Frank, Jan and Hodgson, Jonathan M. and Moreira-Rosário, André and Seal, Chris J. and Buyken, Anette and Rosendahl-Riise, Hanne}},
issn = {{2161-8313}},
journal = {{Advances in Nutrition}},
keywords = {{Nutrition and Dietetics, Medicine (miscellaneous), Food Science}},
number = {{1}},
pages = {{30--43}},
publisher = {{Elsevier BV}},
title = {{{The Effect of Regular Consumption of Reformulated Breads on Glycemic Control: A Systematic Review and Meta-Analysis of Randomized Clinical Trials}}},
doi = {{10.1016/j.advnut.2022.10.008}},
volume = {{14}},
year = {{2022}},
}
@inproceedings{33739,
abstract = {{At least 5% of questions submitted to search engines ask about cause-effect relationships in some way. To support the development of tailored approaches that can answer such questions, we construct Webis-CausalQA-22, a benchmark corpus of 1.1 million causal questions with answers. We distinguish different types of causal questions using a novel typology derived from a data-driven, manual analysis of questions from ten large question answering (QA) datasets. Using high-precision lexical rules, we extract causal questions of each type from these datasets to create our corpus. As an initial baseline, the state-of-the-art QA model UnifiedQA achieves a ROUGE-L F1 score of 0.48 on our new benchmark.}},
author = {{Bondarenko, Alexander and Wolska, Magdalena and Heindorf, Stefan and Blübaum, Lukas and Ngonga Ngomo, Axel-Cyrille and Stein, Benno and Braslavski, Pavel and Hagen, Matthias and Potthast, Martin}},
booktitle = {{Proceedings of the 29th International Conference on Computational Linguistics}},
pages = {{3296–3308}},
publisher = {{International Committee on Computational Linguistics}},
title = {{{CausalQA: A Benchmark for Causal Question Answering}}},
year = {{2022}},
}
@inproceedings{31871,
author = {{Kletetzka, Ivo and Klippstein, Sven Helge}},
booktitle = {{3D-DRUCK HAUTNAH - Der Einfluss einer Zukunftstechnologie auf unser Leben }},
location = {{Paderborn}},
publisher = {{Universität Paderborn}},
title = {{{Pulver im 3D-Druck - von Mascarabürsten bis zum Interieur eines Mini-Coopers (Vortrag)}}},
year = {{2022}},
}
@article{47961,
abstract = {{Due to failures or even the absence of an electricity grid, microgrid systems are becoming popular solutions for electrifying African rural communities. However, they are heavily stressed and complex to control due to their intermittency and demand growth. Demand side management (DSM) serves as an option to increase the level of flexibility on the demand side by scheduling users’ consumption patterns profiles in response to supply. This paper proposes a demand-side management strategy based on load shifting and peak clipping. The proposed approach was modelled in a MATLAB/Simulink R2021a environment and was optimized using the artificial neural network (ANN) algorithm. Simulations were carried out to test the model’s efficacy in a stand-alone PV-battery microgrid in East Africa. The proposed algorithm reduces the peak demand, smoothing the load profile to the desired level, and improves the system’s peak to average ratio (PAR). The presence of deferrable loads has been considered to bring more flexible demand-side management. Results promise decreases in peak demand and peak to average ratio of about 31.2% and 7.5% through peak clipping. In addition, load shifting promises more flexibility to customers.}},
author = {{Philipo, Godiana Hagile and Kakande, Josephine Nakato and Krauter, Stefan}},
issn = {{1996-1073}},
journal = {{Energies}},
keywords = {{Energy (miscellaneous), Energy Engineering and Power Technology, Renewable Energy, Sustainability and the Environment, Electrical and Electronic Engineering, Control and Optimization, Engineering (miscellaneous), Building and Construction}},
number = {{14}},
publisher = {{MDPI AG}},
title = {{{Neural Network-Based Demand-Side Management in a Stand-Alone Solar PV-Battery Microgrid Using Load-Shifting and Peak-Clipping}}},
doi = {{10.3390/en15145215}},
volume = {{15}},
year = {{2022}},
}
@inproceedings{31066,
abstract = {{While trade-offs between modeling effort and model accuracy remain a major concern with system identification, resorting to data-driven methods often leads to a complete disregard for physical plausibility. To address this issue, we propose a physics-guided hybrid approach for modeling non-autonomous systems under control. Starting from a traditional physics-based model, this is extended by a recurrent neural network and trained using a sophisticated multi-objective strategy yielding physically plausible models. While purely data-driven methods fail to produce satisfying results, experiments conducted on real data reveal substantial accuracy improvements by our approach compared to a physics-based model. }},
author = {{Schön, Oliver and Götte, Ricarda-Samantha and Timmermann, Julia}},
booktitle = {{14th IFAC Workshop on Adaptive and Learning Control Systems (ALCOS 2022)}},
keywords = {{neural networks, physics-guided, data-driven, multi-objective optimization, system identification, machine learning, dynamical systems}},
location = {{Casablanca, Morocco}},
number = {{12}},
pages = {{19--24}},
title = {{{Multi-Objective Physics-Guided Recurrent Neural Networks for Identifying Non-Autonomous Dynamical Systems}}},
doi = {{https://doi.org/10.1016/j.ifacol.2022.07.282}},
volume = {{55}},
year = {{2022}},
}
@inproceedings{29803,
abstract = {{Ultrasonic wire bonding is a solid-state joining process used to form electrical interconnections in micro and
power electronics and batteries. A high frequency oscillation causes a metallurgical bond deformation in
the contact area. Due to the numerous physical influencing factors, it is very difficult to accurately capture
this process in a model. Therefore, our goal is to determine a suitable feed-forward control strategy for the
bonding process even without detailed model knowledge. We propose the use of batch constrained Bayesian
optimization for the control design. Hence, Bayesian optimization is precisely adapted to the application of
bonding: the constraint is used to check one quality feature of the process and the use of batches leads to
more efficient experiments. Our approach is suitable to determine a feed-forward control for the bonding
process that provides very high quality bonds without using a physical model. We also show that the quality
of the Bayesian optimization based control outperforms random search as well as manual search by a user.
Using a simple prior knowledge model derived from data further improves the quality of the connection.
The Bayesian optimization approach offers the possibility to perform a sensitivity analysis of the control
parameters, which allows to evaluate the influence of each control parameter on the bond quality. In summary,
Bayesian optimization applied to the bonding process provides an excellent opportunity to develop a feedforward
control without full modeling of the underlying physical processes.}},
author = {{Hesse, Michael and Hunstig, Matthias and Timmermann, Julia and Trächtler, Ansgar}},
booktitle = {{Proceedings of the 11th International Conference on Pattern Recognition Applications and Methods (ICPRAM)}},
isbn = {{978-989-758-549-4}},
keywords = {{Bayesian optimization, Wire bonding, Feed-forward control, model-free design}},
location = {{Online}},
pages = {{383--394}},
title = {{{Batch Constrained Bayesian Optimization for UltrasonicWire Bonding Feed-forward Control Design}}},
year = {{2022}},
}
@inproceedings{58297,
abstract = {{AbstractManually exploring the solution space for different variants of a product for a given set of requirements is ineffective regarding product development time and adaptation to dynamic customer requirements. Variant generation coupled to optimization algorithms offers possibilities to search the solution space in an automated way. This paper provides a framework to build a generative parametric design environment for functional assemblies by implementing analysis as well as synthesis methods in computer-aided tools. The procedure is presented using the example of a coffee machine.}},
author = {{Altun, Osman and Yinanc, Kutay and Mozgova, Iryna and Lachmayer, Roland}},
booktitle = {{Proceedings of the Design Society}},
issn = {{2732-527X}},
pages = {{553--562}},
publisher = {{Cambridge University Press (CUP)}},
title = {{{Procedure to Create an Automated Design Environment for Functional Assemblies}}},
doi = {{10.1017/pds.2022.57}},
volume = {{2}},
year = {{2022}},
}
@article{59504,
abstract = {{In this article, we are interested in optimal aircraft trajectories in climbing phase. We consider the cost index criterion which is a convex combination of the time-to-climb and the fuel consumption. We assume that the thrust is constant and we control the flight path angle of the aircraft. This optimization problem is modeled as a Mayer optimal control problem with a single-input affine dynamics in the control and with two pure state constraints, limiting the Calibrated AirSpeed (CAS) and the Mach speed. The candidates as minimizers are selected among a set of extremals given by the maximum principle. We first analyze the minimum time-to-climb problem with respect to the bounds of the state constraints, combining small time analysis, indirect multiple shooting and homotopy methods with monitoring. This investigation emphasizes two strategies: the common CAS/Mach procedure in aeronautics and the classical Bang-Singular-Bang policy in control theory. We then compare these two procedures for the cost index criterion.}},
author = {{Cots, Olivier and Gergaud, Joseph and Goubinat, Damien and Wembe, Boris}},
issn = {{2822-7840}},
journal = {{ESAIM: Mathematical Modelling and Numerical Analysis}},
number = {{2}},
pages = {{817--839}},
publisher = {{EDP Sciences}},
title = {{{Singular versus boundary arcs for aircraft trajectory optimization in climbing phase}}},
doi = {{10.1051/m2an/2022101}},
volume = {{57}},
year = {{2022}},
}
@article{59617,
abstract = {{There is an increasing interest in sensing applications for a variety of analytes in aqueous environments, as conventional methods do not work reliably under humid conditions or they require complex equipment with experienced operators. Hydrogel sensors are easy to fabricate, are incredibly sensitive, and have broad dynamic ranges. Experiments on their robustness, reliability, and reusability have indicated the possible long-term applications of these systems in a variety of fields, including disease diagnosis, detection of pharmaceuticals, and in environmental testing. It is possible to produce hydrogels, which, upon sensing a specific analyte, can adsorb it onto their 3D-structure and can therefore be used to remove them from a given environment. High specificity can be obtained by using molecularly imprinted polymers. Typical detection principles involve optical methods including fluorescence and chemiluminescence, and volume changes in colloidal photonic crystals, as well as electrochemical methods. Here, we explore the current research utilizing hydrogel-based sensors in three main areas: (1) biomedical applications, (2) for detecting and quantifying pharmaceuticals of interest, and (3) detecting and quantifying environmental contaminants in aqueous environments.}},
author = {{Völlmecke, Katharina and Afroz, Rowshon and Bierbach, Sascha and Brenker, Lee Josephine and Frücht, Sebastian and Glass, Alexandra and Giebelhaus, Ryland and Hoppe, Axel and Kanemaru, Karen and Lazarek, Michal and Rabbe, Lukas and Song, Longfei and Velasco Suarez, Andrea and Wu, Shuang and Serpe, Michael and Kuckling, Dirk}},
issn = {{2310-2861}},
journal = {{Gels}},
number = {{12}},
publisher = {{MDPI AG}},
title = {{{Hydrogel-Based Biosensors}}},
doi = {{10.3390/gels8120768}},
volume = {{8}},
year = {{2022}},
}
@article{63994,
abstract = {{Six cluster salts which consist of hexanuclear cluster anions [Nb6Cl12iX6a]2– (X = Cl or Br) and protonated crown ether molecules (15-crown-5 (15cr5) and 12-crown-4 (12cr4)) or crown ether-stabilized oxonium cations as well as one compound consisting of neutral cluster units, [Nb6Cl16(H2O)2]·4 dioxane, were synthesized in good to high yields. The single-crystal X-ray structures of six of these compounds were determined. The cation/anion ratios and the bond distances confirm in all cases oxidized cluster cores with 14 cluster-based electrons. The cations of the cluster salts are either sandwich-type dimers of the formula [(15cr5)H]22+ or [(15cr5)(H3O)]22+ with the protons or oxonium ions embedded in between the crown ether rings or monomeric units in the case of [(12cr4)H]+. 1H NMR investigations show that the cluster salts are strong Brønsted acids. The fact that the cluster core of [Nb6Cl16(H2O)2]·4 dioxane is oxidized but still carries water ligands indicates that within the multi-step reaction sequence of the formation of the cluster-supported acids, the oxidation step happens much faster than the ligand exchange steps. Temperature-dependent 2H MAS NMR spectra of deuterium-exchanged [(15cr5)H]2[Nb6Cl18]·2 CHCl3 are indicative of dynamic processes of the hydrogen-bonded protons within the crown ether molecule. Six cluster salts which consist of hexanuclear cluster anions [Nb6Cl12iX6a]2– (X = Cl or Br) and protonated crown ether molecules (15-crown-5 (15cr5) and 12-crown-4 (12cr4)) or crown ether-stabilized oxonium cations as well as one compound consisting of neutral cluster units, [Nb6Cl16(H2O)2]·4 dioxane, were synthesized in good to high yields. The single-crystal X-ray structures of six of these compounds were determined. The cation/anion ratios and the bond distances confirm in all cases oxidized cluster cores with 14 cluster-based electrons. The cations of the cluster salts are either sandwich-type dimers of the formula [(15cr5)H]22+ or [(15cr5)(H3O)]22+ with the protons or oxonium ions embedded in between the crown ether rings or monomeric units in the case of [(12cr4)H]+. 1H NMR investigations show that the cluster salts are strong Brønsted acids. The fact that the cluster core of [Nb6Cl16(H2O)2]·4 dioxane is oxidized but still carries water ligands indicates that within the multi-step reaction sequence of the formation of the cluster-supported acids, the oxidation step happens much faster than the ligand exchange steps. Temperature-dependent 2H MAS NMR spectra of deuterium-exchanged [(15cr5)H]2[Nb6Cl18]·2 CHCl3 are indicative of dynamic processes of the hydrogen-bonded protons within the crown ether molecule.}},
author = {{Koenig, Jonas and Gutmann, Torsten and Buntkowsky, Gerd and Koeckerling, Martin}},
journal = {{Inorganic Chemistry}},
number = {{40}},
pages = {{15983–15990}},
publisher = {{American Chemical Society}},
title = {{{Strong Cluster-Supported Brønsted Acids: Hexanuclear Niobium Cluster Compounds with Protonated Crown Ether Cations: (Crown-H)2[Nb6Cl12iX6a] (X = Cl or Br) and the Intermediate [Nb6Cl16(H2O)2]·4 dioxane}}},
volume = {{61}},
year = {{2022}},
}