TY - JOUR
AB - In clinching, the combinations of requirements, materials, component dimensions and tools influence the resulting joint geometry and the resulting bonding mechanisms. These in turn affect the property profile of the joint. For example, it is possible to use different tools to flexibly adapt clinching points to the respective required load regime. Clinching points dimensioned in this way can be geometrically similar, but have different mechanical stress states, which leads to different properties in terms of load-bearing behavior. Within the scope of this work, the clinching process with different tools in optimal and compromise design and its effect on the force and form-closure component, is investigated in a torsion test of the clinched connection. Clinched steel sheets with two thicknesses and joining directions are analyzed. Virtual experiments are carried out using finite element analyses (FEA) of the joining process and are followed by a springback simulation. Subsequently, the surface pressure between the two joining partners in the clinching points is calculated on the basis of the results from the FEA and the transmittable moment of the connection, as an indicator for the force-closure component, is determined. Finally, the experimental and simulated data are compared and discussed.
AU - Steinfelder, C.
AU - Kalich, J.
AU - Brosius, A.
AU - Füssel, U.
ID - 30648
JF - IOP Conference Series: Materials Science and Engineering
TI - Numerical and experimental investigation of the transmission moment of clinching points
VL - 1157
ER -
TY - JOUR
AB - Continuous Fiber Reinforced Thermoplastic (CFRT) hybrid parts offer interesting possibilities for lightweight application, which can exceed the capabilities of mono material metal or CFRT parts. In this case, the joining technology oftentimes is the limiting factor. This study investigates a joining operation with metal pin structures which are additively manufactured via powder bed fusion featuring different diameters and tip geometries, which are inserted into the locally infrared heated CFRT part. The resulting fiber rearrangement is assessed using transmitted light microscopy, confocal laser scanning microscopy as well as micro-computer-tomography. It could be shown that for all assessed pin variants a similar distinct fiber displacement can be seen and that the pin diameter has a significant effect on the resulting fiber orientation with smaller pin diameters being advantageous because of gentle fiber displacement and reduced undulation. The tip geometry has only minor effect on the fiber orientation. Especially in the X/Y plane no systematic influence of the tip geometry on the fiber displacement could be observed. Based on the gained insights a three-stage model of the fiber orientation processes is proposed.
AU - Popp, J.
AU - Kleffel, T.
AU - Römisch, D.
AU - Papke, T.
AU - Merklein, M.
AU - Drummer, D.
ID - 30653
JF - Applied Composite Materials
TI - Fiber Orientation Mechanism of Continuous Fiber Reinforced Thermoplastics Hybrid Parts Joined with Metallic Pins
VL - 28
ER -
TY - JOUR
AB - Clinching continuous fibre reinforced thermoplastic composites and metals is challenging due to the low ductility of the composite material. Therefore, a number of novel clinching technologies has been developed specifically for these material combinations. A systematic overview of these advanced clinching methods is given in the present paper. With a focus on process design, three selected clinching methods suitable for different joining tasks are described in detail. The clinching processes including equipment and tools, observed process phenomena and the resultant material structure are compared. Process phenomena during joining are explained in general and compared using computed tomography and micrograph images for each process. In addition the load bearing behaviour and the corresponding failure mechanisms are investigated by means of single-lap shear tests. Finally, the new joining technologies are discussed regarding application relevant criteria.
AU - Gröger, B.
AU - Troschitz, J.
AU - Vorderbrüggen, J.
AU - Vogel, C.
AU - Kupfer, R.
AU - Meschut, G.
AU - Gude, M.
ID - 30652
JF - Materials
TI - Clinching of Thermoplastic Composites and Metals—A Comparison of Three Novel Joining Technologies
VL - 14
ER -
TY - JOUR
AB - Industrial X-ray computed tomography (XCT) is a tool for non-destructive testing and a volumetric analysis method with the ability to measure dimensions and geometry inside a component without destroying it. However, XCT is a relatively young technology in the field of dimensional metrology and thus faces several challenges. The achievement of a high measurement resolution, which is re-quired to detect small geometrical features, depends on a variety of influencing factors. In this arti-cle, the interface structural resolution (ISR) as one of the key challenges will be investigated. The two-sphere standard called the hourglass standard allows the determination of the structural resolu-tion by evaluation of the surrounding area of an ideal point contact of two spheres after the CT re-construction in form of a neck-shaped transition. Close to the contact point of the two spheres two opposing surfaces exist. Their distances from each other increase as the distance from the contact point of the two spheres increase. The determination of the distances between the spheres’ surface allows a statement about the ISR. A new developed specimen or standard with a variable gap size consisting of calibrated parallel gauge blocks allows statements about the ISR, too. Because of the higher number of probing points of the gauge block standard the results of the determined ISR are more stable compared to the hourglass standard. This paper compares the results of the computed tomography measurements for the designed interface structural resolution standard with those of the hourglass standard.
AU - Busch, M.
AU - Hausotte, T.
ID - 30662
JF - Key Engineering Materials
TI - Determination of the Interface Structural Resolution of an Industrial X-Ray Computed Tomograph Using a Spherical Specimen and a Gap Specimen Consisting of Gauge Blocks
VL - 883
ER -
TY - CONF
AB - Several algorithms for finding the best arm in the dueling bandits setting assume the existence of a Condorcet winner (CW), that is, an arm that uniformly dominates all other arms. Yet, by simply relying on this assumption but not verifying it, such algorithms may produce doubtful results in cases where it actually fails to hold. Even worse, the problem may not be noticed, and an alleged CW still be produced. In this paper, we therefore address the problem as a ”testification” task, by which we mean a combination of testing and identification: The online identification of the CW is combined with the statistical testing of the CW assumption. Thus, instead of returning a supposed CW at some point, the learner has the possibility to stop sampling and refuse an answer in case it feels confident that the CW assumption is violated. Analyzing the testification problem formally, we derive lower bounds on the expected sample complexity of any online algorithm solving it. Moreover, a concrete algorithm is proposed, which achieves the optimal sample complexity up to logarithmic terms.
AU - Haddenhorst, Björn
AU - Bengs, Viktor
AU - Brandt, Jasmin
AU - Hüllermeier, Eyke
ED - de Campos, Cassio
ED - Maathuis, Marloes H.
ID - 30725
T2 - Proceedings of the Thirty-Seventh Conference on Uncertainty in Artificial Intelligence
TI - Testification of Condorcet Winners in dueling bandits
VL - 161
ER -
TY - JOUR
AB - In lightweight design, clinching is a cost-efficient solution as the joint is created through localized cold-forming of the joining parts. A clinch point’s quality is usually assessed using ex-situ destructive testing methods. These, however, are unable to detect phenomena immediately during the joining process. For instance, elastic deformations reverse and cracks close after unloading. In-situ methods such as the force-displacement evaluation are used to control a clinching process, though deviations in the clinch point geometry cannot be derived with this method. To overcome these limitations, the clinching process can be investigated using in-situ computed tomography (in-situ CT). However, a clinching tool made of steel would cause strong artefacts and a high attenuation in the CT measurement, reducing the significance of this method. Additionally, when joining parts of the same material, the sheet-sheet interface is hardly detectable. This work aims at identifying, firstly, tool materials that allow artefact-reduced CT measurements during clinching, and, secondly, radiopaque materials that can be applied between the joining parts to enhance the detectability of the sheet-sheet interface. Therefore, both CT-suitable tool materials and radiopaque materials are selected and experimentally investigated. In the clinching process, two aluminium sheets with radiopaque material in between are clinched in a single-step (rotationally symmetric joint without cut section). It is shown that e.g. silicon nitride is suited as tool material and a tin layer is suitable to enhance the detectability of the sheet-sheet interface.
AU - Köhler, D.
AU - Kupfer, R.
AU - Troschitz, J.
AU - Gude, M.
ID - 30659
JF - ESAFORM 2021
TI - Clinching in In-situ CT – Experimental Study on Suitable Tool Materials
ER -
TY - JOUR
AB - As lightweight design gains more and more attention, time and cost-efficient joining methods such as clinching are becoming more popular. A clinch point’s quality is usually determined by ex situ destructive analyses such as microsectioning. However, these methods do not yield the detection of phenomena occurring during loading such as elastic deformations and cracks that close after unloading. Alternatively, in situ computed tomography (in situ CT) can be used to investigate the loading process of clinch points. In this paper, a method for in situ CT analysis of a single-lap shear test with clinched metal sheets is presented at the example of a clinched joint with two 2 mm thick aluminum sheets. Furthermore, the potential of this method to validate numerical simulations is shown. Since the sheets’ surfaces are locally in contact with each other, the interface between both aluminum sheets and therefore the exact contour of the joining partners is difficult to identify in CT analyses. To compensate for this, the application of copper varnish between the sheets is investigated. The best in situ CT results are achieved with both sheets treated. It showed that with this treatment, in situ CT is suitable to properly observe the three-dimensional deformation behavior and to identify the failure modes.
AU - Köhler, D.
AU - Kupfer, R.
AU - Troschitz, J.
AU - Gude, M.
ID - 30661
JF - Materials
TI - In Situ Computed Tomography—Analysis of a Single-Lap Shear Test with Clinch Points
VL - 14
ER -
TY - JOUR
AB - Due to increasing demands regarding ecological and economic specifications in vehicle design, the effort required for production is continuously increasing. One trend is the increased use of multi-material systems, which are characterised by the use of different materials such as high-strength steels or aluminium alloys. In addition to the varying mechanical properties of the components, an increased number of variants accompanied by different geometries is leading to increasing challenges on body construction. For the assembly and connection of the individual components, conventional joining methods reach their limitations. Therefore, new joining methods are necessary, which feature properties of versatility and can adapt to process and disturbance variables. One way of achieving tailored joints is to use a tumbling self-piercing riveting process. For the design of the process route, numerical investigations are necessary for which a characterisation of the friction properties is necessary. This paper therefore investigates the contact and friction conditions that occur in a tumbling self-piercing riveting process. The individual contacts between the process components are identified and based on this, suitable processes for the characterisation of the friction factors - and coefficients are selected and performed.
AU - Wituschek, S.
AU - Lechner, M.
ID - 30719
JF - Key Engineering Materials
TI - Friction Characterisation for a Tumbling Self-Piercing Riveting Process
VL - 883
ER -
TY - CONF
AU - Haddenhorst, Björn
AU - Bengs, Viktor
AU - Hüllermeier, Eyke
ED - Beygelzimer, A.
ED - Dauphin, Y.
ED - Liang, P.
ED - Vaughan, J. Wortman
ID - 30723
T2 - Advances in Neural Information Processing Systems
TI - Identification of the Generalized Condorcet Winner in Multi-dueling Bandits
ER -
TY - GEN
AU - Peckhaus, Volker
ID - 17751
T2 - Staatslexikon. Recht, Wirtschaft, Gesellschaft, Bd. 5: Schule - Virtuelle Realität
TI - Technikphilosophie
ER -
TY - GEN
AB - Information exchange over networks can be affected by various forms of delay.
This causes challenges for using the network by a multi-agent system to solve a
distributed optimisation problem. Distributed optimisation schemes, however,
typically do not assume network models that are representative for real-world
communication networks, since communication links are most of the time
abstracted as lossless. Our objective is therefore to formulate a
representative network model and provide practically verifiable network
conditions that ensure convergence of distributed algorithms in the presence of
interference and possibly unbounded delay. Our network is modelled by a
sequence of directed-graphs, where to each network link we associate a process
for the instantaneous signal-to-interference-plus-noise ratio. We then
formulate practical conditions that can be verified locally and show that the
age of information (AoI) associated with data communicated over the network is
in $\mathcal{O}(\sqrt{n})$. Under these conditions we show that a penalty-based
gradient descent algorithm can be used to solve a rich class of stochastic,
constrained, distributed optimisation problems. The strength of our result lies
in the bridge between practical verifiable network conditions and an abstract
optimisation theory. We illustrate numerically that our algorithm converges in
an extreme scenario where the average AoI diverges.
AU - Redder, Adrian
AU - Ramaswamy, Arunselvan
AU - Karl, Holger
ID - 30792
T2 - arXiv:2105.04230
TI - Practical sufficient conditions for convergence of distributed
optimisation algorithms over communication networks with interference
ER -
TY - CONF
AB - Graph neural networks (GNNs) have been successfully applied in many structured data domains, with applications ranging from molecular property prediction to the analysis of social networks. Motivated by the broad applicability of GNNs, we propose the family of so-called RankGNNs, a combination of neural Learning to Rank (LtR) methods and GNNs. RankGNNs are trained with a set of pair-wise preferences between graphs, suggesting that one of them is preferred over the other. One practical application of this problem is drug screening, where an expert wants to find the most promising molecules in a large collection of drug candidates. We empirically demonstrate that our proposed pair-wise RankGNN approach either significantly outperforms or at least matches the ranking performance of the naive point-wise baseline approach, in which the LtR problem is solved via GNN-based graph regression.
AU - Damke, Clemens
AU - Hüllermeier, Eyke
ED - Soares, Carlos
ED - Torgo, Luis
ID - 27381
KW - Graph-structured data
KW - Graph neural networks
KW - Preference learning
KW - Learning to rank
SN - 0302-9743
T2 - Proceedings of The 24th International Conference on Discovery Science (DS 2021)
TI - Ranking Structured Objects with Graph Neural Networks
VL - 12986
ER -
TY - GEN
AB - Automated machine learning (AutoML) strives for the automatic configuration
of machine learning algorithms and their composition into an overall (software)
solution - a machine learning pipeline - tailored to the learning task
(dataset) at hand. Over the last decade, AutoML has developed into an
independent research field with hundreds of contributions. While AutoML offers
many prospects, it is also known to be quite resource-intensive, which is one
of its major points of criticism. The primary cause for a high resource
consumption is that many approaches rely on the (costly) evaluation of many
machine learning pipelines while searching for good candidates. This problem is
amplified in the context of research on AutoML methods, due to large scale
experiments conducted with many datasets and approaches, each of them being run
with several repetitions to rule out random effects. In the spirit of recent
work on Green AI, this paper is written in an attempt to raise the awareness of
AutoML researchers for the problem and to elaborate on possible remedies. To
this end, we identify four categories of actions the community may take towards
more sustainable research on AutoML, i.e. Green AutoML: design of AutoML
systems, benchmarking, transparency and research incentives.
AU - Tornede, Tanja
AU - Tornede, Alexander
AU - Hanselle, Jonas Manuel
AU - Wever, Marcel Dominik
AU - Mohr, Felix
AU - Hüllermeier, Eyke
ID - 30866
T2 - arXiv:2111.05850
TI - Towards Green Automated Machine Learning: Status Quo and Future Directions
ER -
TY - JOUR
AU - Schulz, Andreas
AU - Wecker, Christian
AU - Inguva, Venkatesh
AU - Lopatin, Alexey S.
AU - Kenig, Eugeny Y.
ID - 30864
JF - Chemical Engineering Science
KW - Applied Mathematics
KW - Industrial and Manufacturing Engineering
KW - General Chemical Engineering
KW - General Chemistry
SN - 0009-2509
TI - A PLIC-based method for species mass transfer at free fluid interfaces
VL - 251
ER -
TY - THES
AU - Wever, Marcel Dominik
ID - 27284
TI - Automated Machine Learning for Multi-Label Classification
ER -
TY - JOUR
AB - Abstract
Background
Hand amputation can have a truly debilitating impact on the life of the affected person. A multifunctional myoelectric prosthesis controlled using pattern classification can be used to restore some of the lost motor abilities. However, learning to control an advanced prosthesis can be a challenging task, but virtual and augmented reality (AR) provide means to create an engaging and motivating training.
Methods
In this study, we present a novel training framework that integrates virtual elements within a real scene (AR) while allowing the view from the first-person perspective. The framework was evaluated in 13 able-bodied subjects and a limb-deficient person divided into intervention (IG) and control (CG) groups. The IG received training by performing simulated clothespin task and both groups conducted a pre- and posttest with a real prosthesis. When training with the AR, the subjects received visual feedback on the generated grasping force. The main outcome measure was the number of pins that were successfully transferred within 20 min (task duration), while the number of dropped and broken pins were also registered. The participants were asked to score the difficulty of the real task (posttest), fun-factor and motivation, as well as the utility of the feedback.
Results
The performance (median/interquartile range) consistently increased during the training sessions (4/3 to 22/4). While the results were similar for the two groups in the pretest, the performance improved in the posttest only in IG. In addition, the subjects in IG transferred significantly more pins (28/10.5 versus 14.5/11), and dropped (1/2.5 versus 3.5/2) and broke (5/3.8 versus 14.5/9) significantly fewer pins in the posttest compared to CG. The participants in IG assigned (mean ± std) significantly lower scores to the difficulty compared to CG (5.2 ± 1.9 versus 7.1 ± 0.9), and they highly rated the fun factor (8.7 ± 1.3) and usefulness of feedback (8.5 ± 1.7).
Conclusion
The results demonstrated that the proposed AR system allows for the transfer of skills from the simulated to the real task while providing a positive user experience. The present study demonstrates the effectiveness and flexibility of the proposed AR framework. Importantly, the developed system is open source and available for download and further development.
AU - Boschmann, Alexander
AU - Neuhaus, Dorothee
AU - Vogt, Sarah
AU - Kaltschmidt, Christian
AU - Platzner, Marco
AU - Dosen, Strahinja
ID - 30906
IS - 1
JF - Journal of NeuroEngineering and Rehabilitation
KW - Health Informatics
KW - Rehabilitation
SN - 1743-0003
TI - Immersive augmented reality system for the training of pattern classification control with a myoelectric prosthesis
VL - 18
ER -
TY - JOUR
AU - Rodriguez, Alfonso
AU - Otero, Andres
AU - Platzner, Marco
AU - De la Torre, Eduardo
ID - 30907
JF - IEEE Transactions on Computers
KW - Computational Theory and Mathematics
KW - Hardware and Architecture
KW - Theoretical Computer Science
KW - Software
SN - 0018-9340
TI - Exploiting Hardware-Based Data-Parallel and Multithreading Models for Smart Edge Computing in Reconfigurable FPGAs
ER -
TY - JOUR
AB - Wood fiber reinforcement of plastics is almost limited to polypropylene, polyethylene, polyvinyl chloride and polystyrene. Wood fiber reinforcement of thermoplastic polyurethanes (TPU) is a new research field and paltry studied scientifically. Wood fiber reinforcement can carry out synergistic effects between sustainability, material or product price reduction, improved mechanical properties at high elongation, and brilliant appearance and haptics. In order to evaluate to what extent the improvement of mechanical properties depend on material-specific parameters (fiber type, fiber content) and on process-specific parameters (holding pressure, temperature control and injection speed), differently filled compounds were injection molded according to a partial factorial test plan and subjected to characterizing test procedures (tensile test, Shore hardness and notched impact test). Tensile strength showed significant dependence on barrel temperature, fiber type and interaction between holding pressure and barrel temperature in the region of interest. Young’s modulus can be influenced by fiber content but not by fiber type. Notched impact strength showed a significant influence of cylinder temperature, fiber content, fiber type and the interaction between cylinder temperature and fiber content in the region of interest. Shore hardness is related to fiber content and the interaction between mold temperature and injection flow rate. Our results show not only that wood-filled TPU can be processed very well by injection molding, but also that the mechanical properties depend significantly on temperature control in the injection-molding process. Moreover, considering the significant reinforcing effect of the wood fibers, a good fiber-matrix adhesion can be assumed.
AU - Moritzer, Elmar
AU - Richters, Maximilian
ID - 30924
IS - 12
JF - Journal of Composites Science
KW - Engineering (miscellaneous)
KW - Ceramics and Composites
SN - 2504-477X
TI - Injection Molding of Wood-Filled Thermoplastic Polyurethane
VL - 5
ER -
TY - JOUR
AU - Moritzer, Elmar
AU - Richters, Maximilian
ID - 23944
JF - Journal of Applied Polymer Science
TI - Characterization of wood-filled thermoplastic polyurethane for the injection modling process
ER -
TY - JOUR
AU - Moritzer, Elmar
AU - Richters, Maximilian
AU - Hillemeyer, Johannes
AU - Krassmann, Dimitri
ID - 23948
JF - Joining Plastics
TI - Mit dem Schraubblind-Durchsetznieten Metallteile mit Composites bei einseitiger Zugänglichkeit verbinden
ER -
TY - JOUR
AU - Kastein, Mara
AU - Finke, Josefine
AU - Horwath, Ilona
ID - 23886
JF - Voluntaris
SN - 2196-3886
TI - Florian braucht Mehmet mehr als umgekehrt: Herausforderungen und Potenziale für Inklusion in der Freiwilligen Feuerwehr
ER -
TY - GEN
ED - Kastein, Mara
ED - Horwath, Ilona
ED - Finke, Josefine
ED - Duglar Sezer, Nilgün
ID - 24446
T2 - Erscheinungsformen, Erklärungsversuche und Gegenstrategien, GENDER
TI - Ohne den ‚Weissen Mann‘ würden Leute wie Sie noch in Erdhöhlen wohnen.“ - Die Markierung der Unmarkierten
ER -
TY - CHAP
AU - Horwath, Ilona
AU - Kastein, Mara
AU - Duglar Sezer, Nilgün
ED - Duglar Sezer, Nilgün
ED - Horwath, Ilona
ED - Kastein, Mara
ID - 24477
T2 - Feuerwehren im Spiegel gesellschaftlicher Diversität
TI - Feuerwehren im Spiegel gesellschaftlicher Diversität
ER -
TY - JOUR
AB - In dem Artikel werden die Metaphern gleichstellungsorientierter Männerpolitik als eine Form diskursiver Praktiken untersucht. In meiner Dissertation habe ich die Metaphernanalyse ergänzend zur Grounded-Theory-Methodologie und zur wissenssoziologischen Diskursanalyse genutzt, um die Ergebnisse zu verdichten und zu vertiefen. Dabei stellt die Metaphorik der gleichstellungsorientierten Männerpolitik selbige als instabil, schwankend, balancierend und uneinig dar, denn sie wird als schwankendes Schiff, welches ohne feste Route auf dem Meer schaukelt, imaginiert. Das Meer ist die Gesellschaft bzw. die übergeordnete Gleichstellungspolitik. Diese wird als unberechenbar und launisch konzipiert, und die gleichstellungsorientierte Männerpolitik erscheint dabei als ausgeliefert.
AU - Kastein, Mara
ID - 24172
JF - Forum Qualitative Sozialforschung
TI - Das schwankende Schiff der Männerpolitik: eine Metaphernanalyse
ER -
TY - GEN
ED - Alemann, v.Annette
ED - Gruhlich, Julia
ED - Horwath, Ilona
ED - Weber, Lena
ID - 24175
SN - 2570-6578
T2 - Gender a výzkum / Gender and Research
TI - International Perspectives about COVID-19, Digital Labour and Gender Work Pattern: A Collective Interview
ER -
TY - GEN
ED - Alemann, v. Annette
ED - Gruhlich, Julia
ED - Horwath, Ilona
ED - Weber, Lena
ID - 24173
SN - 2570-6578
T2 - Gender a výzkum / Gender and Research
TI - A Plea to Reflect on the Entanglements of Gendered Work Patterns and Digital Technologies
ER -
TY - JOUR
AB - This study deals with the damage behavior of metallic materials by the application of different manufacturing processes and using different optical measurement methods to identify the crack initiation in the damage specimen. The study is intended to highlight the importance of considering manufacturing processes and optical measurement methods in a numerical simulation when analyzing the damage behavior of metallic materials. To describe the damage behavior of the material in the process chain simulations, it is important to calibrate the parameters of damage model more accurately. These parameters are determined using experimental investigation of desired damage specimens. In this regard, a selected damage specimen manufactured by different cutting processes is first experimentally and then numerically investigated. It is shown that the manufacturing process and the optical measurement methods influence the stress state analyzed in the numerical simulation.
AU - Otroshi, Mortaza
AU - Meschut, Gerson
AU - Nesakumar, Aathavan
ID - 25476
IS - 3
JF - Journal of Manufacturing Engineering
KW - Damage behaviour
KW - Stress triaxiality
KW - Manufacturing process and Optical measurement
TI - The influence of manufacturing processes and optical measurement methods on the damage behavior of HX340LAD micro-alloyed steels
VL - 16
ER -
TY - BOOK
AB - The Arburg Plastic Freeforming (APF) is an additive manufacturing process which allows the production of three-dimensional thermoplastic components in layers. The components are produced by depositing fine, molten plastic droplets. The main advantage of the APF is the open-parameter control of the associated machine system. Thus, the process parameters can be optimized for individual applications. A special and new application of the APF is the production of interconnecting porous structures. As this is a novel approach with this manufacturing process, the general producibility and reproducibility must first be proven. Therefore, the relevant process parameters with an influence on the open-pored structures are identified. The volume of the individual plastic droplets, the distance between the droplets and the layer thickness are the three decisive influencing factors. With the use of analysis methods, the free spaces created in the structure are described by a uniformly constructed, interconnected pore structure. This means that the pores are interconnected in three dimensions. Reproducibility is evaluated by repeated production and thru the changed conditions during the manufacturing process. In addition, the multiplication and a change of geometry are evaluated in such a way that there is no influence on the pore size. Irregularities when depositing the first layer are caused by unevenness of the building platform. A suitable test arrangement is set up to determine the liquid permeability. A characteristic value is determined to describe the permeability to liquids.
AU - Moritzer, Elmar
AU - Hirsch, André
AU - Dalmer, C.
ID - 22032
SN - 978-3-030-54333-4
TI - Investigation of Plastic Freeformed, Open-Pored Structures with Regard to Producibility, Reproducibility and Liquid Permeability
ER -
TY - JOUR
AU - Moritzer, Elmar
AU - Wächter, Julian
AU - Elsner, Christian Lennart
ID - 24162
IS - 1
JF - Macromolecular Symposia
TI - Investigation of Specific FDM Process Parameters to Optimize the Polymer Discharge of Carbon Fiber Reinforced PEEK
VL - 395
ER -
TY - JOUR
AU - Moritzer, Elmar
AU - Schumacher, Christian
ID - 24681
IS - 1
JF - Macromolecular Symposia
SN - 1022-1360
TI - Stainless Steel Parts Produced by Fused Deposition Modeling and a Sintering Process Compared to Components Manufactured in Selective Laser Melting
VL - 395
ER -
TY - JOUR
AU - Otroshi, Mortaza
AU - Meschut, Gerson
AU - Bielak, Christian Roman
AU - Masendorf, Lukas
AU - Esderts, Alfons
ID - 21810
JF - Key Engineering Materials
SN - 1662-9795
TI - Modeling of Stiffness Anisotropy in Simulation of Self-Piercing Riveted Components
VL - 883
ER -
TY - CONF
AU - Moritzer, Elmar
AU - Elsner, Christian Lennart
AU - Wächter, Julian
AU - Knoop, Frederick
ID - 24554
T2 - 79th Annual Technical Conference of the Society of Plastics Engineers (ANTEC)
TI - Investigation and Realization of Watertight FDM Structures Made of Ultem 9085 in Pressurized Systems
ER -
TY - JOUR
AB - The joining of plastics is required because component geometries are severely restricted in conventional manufacturing processes such as injection molding or extrusion. In addition to established processes such as hot plate welding, infrared welding, or vibration welding, hot gas butt welding is becoming more and more important industrially due to its advantages. The main benefits are the contactless heating process, the suitability for glass fiber reinforced, and high-temperature plastics as well as complex component geometries. However, various degradation phenomena can occur during the heating process used for economic reasons, due to the presence of oxygen in the air and to the high gas temperatures. In addition, the current patent situation suggests that welding with an oxidizing gas is not permissible depending on the material. On the other hand, however, there is experience from extrusion welding, with which long-term resistant weld seams can be produced using air. Investigations have shown that the same weld seam properties can be achieved with polypropylene using either air or nitrogen as the process gas. Experimental investigations have now been carried out on the suitability of different gases with regard to the weld seam quality when welding polyamides, which are generally regarded as more prone to oxidation. The results show that weld strengths are higher when nitrogen is used as process gas. However, equal weld strengths can be achieved with air and nitrogen when the material contains heat stabilizers.
AU - Bialaschik, Max
AU - Schöppner, Volker
AU - Albrecht, Mirko
AU - Gehde, Michael
ID - 23867
JF - Welding in the World
SN - 0043-2288
TI - Influence of material degradation on weld seam quality in hot gas butt welding of polyamides
ER -
TY - JOUR
AU - Moritzer, Elmar
AU - Elsner, Christian Lennart
AU - Schumacher, Christian
ID - 24555
IS - 11
JF - Polymer Composites
SN - 0272-8397
TI - Investigation of Metal‐Polymer Composites Manufactured by Fused Deposition Modeling with Regard to Process Parameters
VL - 42
ER -
TY - CONF
AU - Wibbeke, Tim Michael
AU - Bartley, Auerélie
AU - Chudalla, Nick
AU - Meschut, Gerson
ID - 26821
T2 - Fahrzeug + Karosserie und kfz-betrieb (Hrsg,); Tagungsband zu den Würzburger Karosserie- und Schadenstagen 22./23. Oktober 2021
TI - Fügen und Trennen von Kfz-Karosseriestrukturen in Leichtbauweise
ER -
TY - JOUR
AU - Gröger, Benjamin
AU - Troschitz, Juliane
AU - Vorderbrüggen, Julian
AU - Vogel, Christian
AU - Kupfer, Robert
AU - Meschut, Gerson
AU - Gude, Maik
ID - 21814
JF - Materials
TI - Clinching of Thermoplastic Composites and Metals—A Comparison of Three Novel Joining Technologies
ER -
TY - JOUR
AB - AbstractRecent developments in automotive and aircraft industry towards a multi-material design pose challenges for modern joining technologies due to different mechanical properties and material compositions of various materials such as composites and metals. Therefore, mechanical joining technologies like clinching are in the focus of current research activities. For multi-material joints of metals and thermoplastic composites thermally assisted clinching processes with advanced tool concepts are well developed. The material-specific properties of fibre-reinforced thermoplastics have a significant influence on the joining process and the resulting material structure in the joining zone. For this reason, it is important to investigate these influences in detail and to understand the phenomena occurring during the joining process. Additionally, this provides the basis for a validation of a numerical simulation of such joining processes. In this paper, the material structure in a joint resulting from a thermally assisted clinching process is investigated. The joining partners are an aluminium sheet and a thermoplastic composite (organo sheet). Using computed tomography enables a three-dimensional investigation that allows a detailed analysis of the phenomena in different joining stages and in the material structure of the finished joint. Consequently, this study provides a more detailed understanding of the material behavior of thermoplastic composites during thermally assisted clinching.
AU - Gröger, Benjamin
AU - Köhler, Daniel
AU - Vorderbrüggen, Julian
AU - Troschitz, Juliane
AU - Kupfer, Robert
AU - Meschut, Gerson
AU - Gude, Maik
ID - 28568
JF - Production Engineering
SN - 0944-6524
TI - Computed tomography investigation of the material structure in clinch joints in aluminium fibre-reinforced thermoplastic sheets
ER -
TY - JOUR
AB - Glass/carbon fiber reinforced plastic (GFRP/CFRP) and hybrid components have attracted increasing attention in lightweight applications. However, residual stresses induced in the manufacturing process of these components can result in warpage and, eventually, negatively affect the mechanical performance of the composite structures. In the present work, GFRP, CFRP, GFRP/steel and CFRP/steel hybrid components were manufactured through the prepreg-press-technology always employing the same process parameters. The residual stresses of these components were measured through the hole drilling method (HDM), based on an adequate formalism to evaluate the residual stresses for orthotropic materials including the calculation of the calibration coefficients via finite element analysis (FEA). In FEA, the real material lay-up and mechanical properties of the samples were considered. The warpage induced by residual stresses was measured after the samples were removed from the tool. The measured residual stresses and warpage of four different types of samples were compared and results were analyzed in depth. The results obtained can be extended to other hybrid materials and even could be used for designing multi-stable laminates for application in adaptive structures. Moreover, the effects of the drilling process parameters of HDM, e.g., the drilling speed, the drilling increment and the zero-depth setting, on the resulting residual stresses of GFRP were investigated. The reliability of residual stress measurements in GFRP using HDM was validated through mechanical bending tests. The conclusions concerning the choice of optimal drilling parameters for GFRP could be directly applied for other types of samples considered in the present work.
AU - Wu, Tao
AU - Tinkloh, Steffen Rainer
AU - Tröster, Thomas
AU - Zinn, Wolfgang
AU - Niendorf, Thomas
ID - 24131
JF - Metals
SN - 2075-4701
TI - Measurement and Analysis of Residual Stresses and Warpage in Fiber Reinforced Plastic and Hybrid Components
ER -
TY - JOUR
AU - Tinkloh, Steffen Rainer
AU - Wu, Tao
AU - Tröster, Thomas
AU - Niendorf, Thomas
ID - 21064
JF - Metals
SN - 2075-4701
TI - The Effect of Fiber Waviness on the Residual Stress State and Its Prediction by the Hole Drilling Method in Fiber Metal Laminates: A Global-Local Finite Element Analysis
ER -
TY - JOUR
AU - Magnier, A.
AU - Wu, T.
AU - Tinkloh, Steffen Rainer
AU - Tröster, Thomas
AU - Scholtes, B.
AU - Niendorf, T.
ID - 24130
JF - Polymer Testing
SN - 0142-9418
TI - On the reliability of residual stress measurements in unidirectional carbon fibre reinforced epoxy composites
ER -
TY - THES
AU - Henkenius, Carsten
ID - 30849
TI - Entwurf netzfreundlicher Synchrongleichrichter mit integriertem Synchronwandler
ER -
TY - JOUR
AU - Claes, Leander
AU - Chatwell, René Spencer
AU - Baumhögger, Elmar
AU - Hetkämper, Tim
AU - Zeipert, Henning
AU - Vrabec, Jadran
AU - Henning, Bernd
ID - 22925
JF - Measurement
SN - 0263-2241
TI - Measurement procedure for acoustic absorption and bulk viscosity of liquids
ER -
TY - CONF
AB - Requirements for energy distribution networks are changing fast due to the growing share of renewable energy, increasing electrification, and novel consumer and asset technologies. Since uncertainties about future developments increase planning difficulty, flexibility potentials such as synergies between the electricity, gas, heat, and transport sector often remain unused. In this paper, we therefore present a novel module-based concept for a decision support system that helps distribution network planners to identify cross-sectoral synergies and to select optimal network assets such as transformers, cables, pipes, energy storage systems or energy conversion technology. The concept enables long-term transformation plans and supports distribution network planners in designing reliable, sustainable and cost-efficient distribution networks for future demands.
AU - Kirchhoff, Jonas
AU - Burmeister, Sascha Christian
AU - Weskamp, Christoph
AU - Engels, Gregor
ED - Breitner, Michael H.
ED - Lehnhoff, Sebastian
ED - Nieße, Astrid
ED - Staudt, Philipp
ED - Weinhardt, Christof
ED - Werth, Oliver
ID - 21093
T2 - Energy Informatics and Electro Mobility ICT
TI - Towards a Decision Support System for Cross-Sectoral Energy Distribution Network Planning
ER -
TY - GEN
AU - Lammer, Christina
ID - 30957
TI - Revolten in Gelb und Grün. In 'Rosa und Hannah. Das Blatt wenden' inspiriert Joke J. Hermsen für Krisenzeiten
ER -
TY - GEN
AU - Moritzer, Elmar
AU - Hillemeyer, Johannes
AU - Kramer, M.
AU - Hopmann, C.
ID - 31744
SN - 1864-3450
T2 - Joining Plastics
TI - Designing of thermosetting plastic components for direct screwing - Auslegung von Duroplastbauteilen zur Direktverschraubung
ER -
TY - GEN
AU - Moritzer, Elmar
AU - Richters, Maximilian
ID - 31740
IS - 38
T2 - Journal of Applied Polymer Science
TI - Characterization of wood-filled thermoplastic polyurethanes for the injection molding process
VL - 138
ER -
TY - CONF
AU - Moritzer, Elmar
AU - Krassmann, Dimitri
AU - Brikmann, Johannes
ID - 31760
T2 - 11. Fügetechnisches Gemeinschaftskolloquium
TI - Entwicklung der Spritzniettechnik als werkstoffgerechtes Fügeverfahren für hybride Strukturen
ER -
TY - GEN
AU - Moritzer, Elmar
AU - Jilg, J.
AU - Rücker, Tobias
ID - 31762
T2 - Kunststoffe
TI - Er kommt auf die Korngröße an, Mikrogranulat verbessert die Verteilung feindisperser Füllstoffe in der Direktcompoundierung
ER -
TY - GEN
AU - Schöppner, Volker
AU - Martens, Jan Hendrik
ID - 31758
SN - 0023- 5563
T2 - Kunststoffe
TI - Eine runde Sache
ER -
TY - CONF
AU - Hopp, Matthias
AU - Tölle, Lisa
ID - 31767
T2 - 36th International Conference of Polymer Processing Society (PPS)
TI - Influence of Fiber Content on the Fiber Dust Formation During Shredding for Mechanical Recycling of Different Glass and Carbon Fiber Reinforced Thermoplastics
ER -
TY - GEN
AU - Moritzer, Elmar
AU - Hillemeyer, Johannes
AU - Lotzin, R.
ID - 31765
SN - 0023-5563
T2 - Kunststoffe
TI - Fügeelement angespritzt - Einfluss auf die Verbundfestigkeit zwischen Organoblech und Schraubblindniet untersucht
ER -
TY - GEN
AU - Moritzer, Elmar
AU - Wortmann, M.
AU - Krieger, P.
AU - Hüsgen, B.
AU - Frese, N.
ID - 31763
T2 - ACS Omega
TI - Effect of Isocyanate Absorption on the Mechanical Properties of Silicone Elastomers in Polyurethane Vacuum Casting
ER -
TY - CONF
AU - Moritzer, Elmar
AU - Wächter, Julian
AU - Fuhrmann, C.
ID - 31774
SN - 1314-7269
T2 - 23rd International Conference Materials
TI - INVESTIGATION OF THE PROCESSABILITY OF DIFFERENT HIGHPERFORMANCE MATERIALS IN THE FDM PROCESS WITH REGARD TO THE SHRINKAGE BEHAVIOR
ER -
TY - GEN
AU - Schöppner, Volker
AU - Gevers, Karina
ID - 31776
SN - 1436-6401
T2 - K-Zeitung
TI - Lebensdauer vorhersagen?
ER -
TY - GEN
AU - Moritzer, Elmar
ID - 31775
T2 - Kunststoffe
TI - Kühlen mit dem Wärmerohr
ER -
TY - CONF
AU - Schöppner, Volker
AU - Altepeter, Matthias
AU - Wanke, Sven
ID - 31777
T2 - 36th International Conference of the Polymer Processing Society (PPS)
TI - Material Degradation of Polypropylene on the Co-Rotating Twin Screw Extruder
ER -
TY - CHAP
AU - Willeke, Stephanie
ED - Gansel, Carsten
ED - Lehnen , Katrin
ED - Oswalt, Vadim
ID - 31718
T2 - Schreiben, Text, Autorschaft II. Zur Narration und Störung von Lebens- und Schreibprozessen
TI - Schriftstellerische Inszenierungspraktiken und autofiktionale Schreibreflexionen im Weblog Turmsegler von Benjamin Stein
ER -
TY - CONF
AU - Moritzer, Elmar
AU - Bürenhaus, Franziska Isabelle
ID - 31781
T2 - 27. Techomer - Fachtagung über Verarbeitung und Anwendung von Polymeren
TI - Untersuchung der Faserlängenabnahme von kurz- und langglasfaserverstärk-ten Thermoplasten im Spritzgießprozess
ER -
TY - CHAP
AU - Willeke, Stephanie
ED - Wolf, Deborah
ED - Podskalsky, Vera
ID - 31724
T2 - Prekäre Fakten, umstrittene Fiktionen. Fake News, Verschwörungstheorien und ihre kulturelle Aushandlung (Philologie im Netz Beiheft 25/2021)
TI - Auf der Grenze zwischen Fakt und Fiktion. Fake News in der Polit-Serie The Good Fight
ER -
TY - GEN
AU - Moritzer, Elmar
AU - Hillemeyer, Johannes
AU - Lotzin, R.
ID - 31778
SN - 1862–4243
T2 - Kunststoffe International
TI - Molding on a Joining Element - Study of the Factors Influencing the Strength of the Bond between a Thermoplastic Composite and a Screw-in Blind Rivet
ER -
TY - GEN
AU - Hopp, Matthias
AU - Tölle, Lisa
AU - Hoemann, Theresa
ID - 31779
T2 - Gummi Fasern Kunststoffe
TI - Reduzierung der Faserstaubentstehung beim mechanischen Recycling - Zerkleinern von carbonfaserverstärkten Polycarbonaten mit unterschiedlichen Verstärkungsformen
ER -
TY - GEN
AU - Moritzer, Elmar
AU - Wortmann, M.
AU - Frese, N.
AU - Brinkmann, J.
AU - Ehrmann, A.
AU - Hüsgen, B.
ID - 31780
T2 - Macromolecular Symposia
TI - Silicone Mold Accuracy in Polyurethane Vacuum Casting
ER -
TY - CONF
AU - Schöppner, Volker
AU - Kleinschmidt, Dennis
ID - 31782
T2 - 27. Techomer - Fachtagung über Verarbeitung und Anwendung von Polymeren
TI - Viskoelastische Materialmodellierung in Strömungssimulationen
ER -
TY - CONF
AU - Schöppner, Volker
AU - Albrecht, M.
AU - Gehde, M.
AU - Bialaschik, Max Oliver
ID - 31785
T2 - Technomer
TI - Warmgasstumpfschweißen - Einfluss des Werkzeugdesigns und des verwendeten Prozessgases auf das Erwärm- und Schweißverhalten
ER -
TY - CONF
AU - Schöppner, Volker
AU - Dörner, M.
AU - Schall, Christoph Wilhelm Theodor
ID - 31784
T2 - Technomer 2021
TI - Vorteilhaftes Prozessverhalten von Wave-Schnecken in der Einschneckenextrusion
ER -
TY - GEN
AU - Schöppner, Volker
AU - Bialaschik, Max Oliver
AU - Albrecht, M.
AU - Gehde, M.
ID - 31786
SN - 1864-3450
T2 - Joining Plastics
TI - Warmgasstumpfschweißen von Kunststoffen
ER -
TY - CHAP
AU - Böker, Ines
ED - Standke, Jan
ID - 31792
T2 - Drama und Theater der Gegenwart. Literarisches Lernen und ästhetische Bildung zwischen Textanalyse und Aufführungsrezeption (Beiträge zur Didaktik der deutschsprachigen Gegenwartsliteratur)
TI - „Transkulturelle Wahrnehmungsräume in der Theaterdidaktik. Die Theaterarbeit von Nuran David Calis“
VL - 8
ER -
TY - GEN
AU - Moritzer, Elmar
AU - Bürenhaus, Franziska Isabelle
ID - 31771
T2 - 36th International Conference of the Polymer Processing Society (PPS)
TI - Investigation of Fiber Orientation and its Influence on Fiber Length Degradation in Simple Shear Flow for Glass Fiber Reinforced Polypropylene
ER -
TY - JOUR
AB - Ideational impact refers to the uptake of a paper's ideas and concepts by subsequent research. It is defined in stark contrast to total citation impact, a measure predominantly used in research evaluation that assumes that all citations are equal. Understanding ideational impact is critical for evaluating research impact and understanding how scientific disciplines build a cumulative tradition. Research has only recently developed automated citation classification techniques to distinguish between different types of citations and generally does not emphasize the conceptual content of the citations and its ideational impact. To address this problem, we develop Deep Content-enriched Ideational Impact Classification (Deep-CENIC) as the first automated approach for ideational impact classification to support researchers' literature search practices. We evaluate Deep-CENIC on 1,256 papers citing 24 information systems review articles from the IT business value domain. We show that Deep-CENIC significantly outperforms state-of-the-art benchmark models. We contribute to information systems research by operationalizing the concept of ideational impact, designing a recommender system for academic papers based on deep learning techniques, and empirically exploring the ideational impact of the IT business value domain.
AU - Prester, Julian
AU - Wagner, Gerit
AU - Schryen, Guido
AU - Hassan, Nik Rushdi
ID - 20212
IS - January
JF - Decision Support Systems
KW - Ideational impact
KW - citation classification
KW - academic recommender systems
KW - natural language processing
KW - deep learning
KW - cumulative tradition
TI - Classifying the Ideational Impact of Information Systems Review Articles: A Content-Enriched Deep Learning Approach
VL - 140
ER -
TY - JOUR
AB - Review papers are essential for knowledge development in IS. While some are cited twice a day, others accumulate single digit citations over a decade. The magnitude of these differences prompts us to analyze what distinguishes those reviews that have proven to be integral to scientific progress from those that might be considered less impactful. Our results highlight differences between reviews aimed at describing, understanding, explaining, and theory testing. Beyond the control variables, they demonstrate the importance of methodological transparency and the development of research agendas. These insights inform all stakeholders involved in the development and publication of review papers.
AU - Wagner, Gerit
AU - Prester, Julian
AU - Roche, Maria
AU - Schryen, Guido
AU - Benlian, Alexander
AU - Paré, Guy
AU - Templier, Mathieu
ID - 20844
IS - 3
JF - Information & Management
KW - Literature review
KW - review papers
KW - scientometric
KW - scientific impact
KW - citation analysis
TI - Which Factors Affect the Scientific Impact of Review Papers in IS Research? A Scientometric Study
VL - 58
ER -
TY - JOUR
AU - Stumpe, Miriam
AU - Rößler, David
AU - Schryen, Guido
AU - Kliewer, Natalia
ID - 23494
JF - EURO Journal on Transportation and Logistics
TI - Study on Sensitivity of Electric Bus Systems under Simultaneous Optimization of Charging Infrastructure and Vehicle Schedules
VL - 10
ER -
TY - JOUR
AU - Wagner, Gerit
AU - Prester, Julian
AU - Schryen, Guido
ID - 17934
IS - 1
JF - Communications of the Association for Information Systems
TI - Exploring the Scientific Impact of Information Systems Design Science Research
VL - 48
ER -
TY - BOOK
AU - Altun, Tülay
AU - Handt, Claudia
AU - Hinrichs, Beatrix
AU - Hoffacker, Anna
AU - Niederhaus, Constanze
AU - Weis, Ingrid
ID - 32030
TI - Sprachbildung in der Grundschule
ER -
TY - CHAP
AU - Dohmann, Olga
AU - Drumm, Sandra
AU - Niederhaus, Constanze
ED - Freudenberg-Findeisen, Renate
ED - Harsch, Claudia
ED - Middeke, Annegret
ID - 32056
T2 - Zur sprachlichen und gesellschaftlichen Integration neu zugewanderter Menschen. Eine Bilanz. Materialien Deutsch als Zweit- und Fremdsprache 105
TI - Schreibberatung im Kontext beruflicher Bildung und ihre Auswirkung auf Emotionen beim Schreiben
ER -
TY - CHAP
AU - Peuschel, Kristina
AU - Petersen, Inger
AU - Reble, Raja
AU - Haberzettl, Stefanie
AU - Berkel-Otto, Lisa
AU - Niederhaus, Constanze
AU - Steinmetz, Sandra
AU - Rojahn, Pia
AU - Sondershaus, Eva
ED - Berkel-Otto, Lisa
ED - Peuschel, Kristina
ED - Steinmetz, Sandra
ID - 32060
T2 - Theorie-Praxis-Verzahnung in der Lehrkräftebildung Ergebnisse aus dem Netzwerk „Stark durch Diversität“
TI - Der besondere Moment - Ergebnisse aus der Evaluation der Projekte „Sprachförderung PLUS“ im Netzwerk „Stark durch Diversität“
ER -
TY - THES
AB - Ein zentraler Aspekt bei der Untersuchung dynamischer Systeme ist die Analyse ihrer invarianten Mengen wie des globalen Attraktors und (in)stabiler Mannigfaltigkeiten. Insbesondere wenn das zugrunde liegende System von einem Parameter abhängt, ist es entscheidend, sie im Bezug auf diesen Parameter effizient zu verfolgen. Für die Berechnung invarianter Mengen stützen wir uns für ihre Approximation auf numerische Algorithmen. Typischerweise können diese Methoden jedoch nur auf endlich-dimensionale dynamische Systeme angewendet werden. In dieser Arbeit präsentieren wir daher einen numerischen Rahmen für die globale dynamische Analyse unendlich-dimensionaler Systeme. Wir werden Einbettungstechniken verwenden, um das core dynamical system (CDS) zu definieren, welches ein dynamisch äquivalentes endlich-dimensionales System ist.Das CDS wird dann verwendet, um eingebettete invariante Mengen, also eins-zu-eins Bilder, mittels Mengen-orientierten numerischen Methoden zu approximieren. Bei der Konstruktion des CDS ist es entscheidend, eine geeignete Beobachtungsabbildung auszuwählen und die geeignete inverse Abbildung zu entwerfen. Dazu werden wir geeignete numerische Implementierungen des CDS für DDEs und PDEs vorstellen. Für eine nachfolgende geometrische Analyse der eingebetteten invarianten Menge betrachten wir eine Lerntechnik namens diffusion maps, die ihre intrinsische Geometrie enthüllt sowie ihre Dimension schätzt. Schließlich wenden wir unsere entwickelten numerischen Methoden an einigen bekannten unendlich-dimensionale dynamischen Systeme an, wie die Mackey-Glass-Gleichung, die Kuramoto-Sivashinsky-Gleichung und die Navier-Stokes-Gleichung.
AU - Gerlach, Raphael
ID - 32057
TI - The Computation and Analysis of Invariant Sets of Infinite-Dimensional Systems
ER -
TY - JOUR
AU - Delarue, Benjamin
AU - Ramacher, Pablo
ID - 32016
IS - 6
JF - Journal of Symplectic Geometry
TI - Asymptotic expansion of generalized Witten integrals for Hamiltonian circle actions
VL - 19
ER -
TY - CONF
AB - Fault coverage analysis and fault simulation are well-established methods for the qualification of test vectors in hardware design. However, their role in virtual prototyping and the correlation to later steps in the design process need further investigation. We introduce a metric for RISC-V instruction and register coverage for binary software. The metric measures if RISC-V instruction types are executed and if GPRs, CSRs, and FPRs are accessed. The analysis is applied by the means of a virtual prototype which is based on an abstract instruction and register model with direct correspondence to their bit level representation. In this context, we analyzed three different openly available test suites: the RISC-V architectural testing framework, the RISC-V unit tests, and programs which are automatically generated by the RISC-V Torture test generator. We discuss their tradeoffs and show that by combining them to a unified test suite we can arrive at a 100% GPR and FPR register coverage and a 98.7% instruction type coverage.
AU - Adelt, Peer
AU - Koppelmann, Bastian
AU - Müller, Wolfgang
AU - Scheytt, Christoph
ID - 32125
SN - 978-3-8007-5500-4
T2 - MBMV 2021 - Methods and Description Languages for Modelling and Verification of Circuits and Systems; GMM/ITG/GI-Workshop
TI - Register and Instruction Coverage Analysis for Different RISC-V ISA Modules
ER -
TY - CONF
AU - Gräßler, Iris
AU - Hesse, Philipp
ID - 24439
TI - Decision Support for Product Specific Recycling
ER -
TY - GEN
AU - Peckhaus, Volker
ID - 28707
T2 - Zentralblatt für Mathematik und ihre Grenzgebiete
TI - Bolzano, Bernard, "Briefe an Michael Josef Fesl 1831–1836", hg. v. Otto Neumaier, Frommann-Holzboog, Eckhart Holzboog: Stuttgart-Bad Cannstatt 2020 (Bernard Bolzano-Gesamtausgabe. Reihe III: Briefwechsel. Bd. 2.2)
ER -
TY - GEN
AU - Peckhaus, Volker
ID - 28705
T2 - Zentralblatt für Mathematik und ihre Grenzgebiete
TI - Negrepontis, Stelios, “Plato on Geometry and the Geometers”, in: S.G. Dani et al. (eds.), Geometry in History, Cham: Springer 2019, 1–88
ER -
TY - GEN
AU - Peckhaus, Volker
ID - 28709
T2 - Zentralblatt für Mathematik und ihre Grenzgebiete
TI - Rusnock, Paul, “Bolzano on Continuity”, in: Stewart Shapiro et. al. (eds.), The History of Continua. Philosophical and Mathematical Perspectives, Oxford: Oxford University Press 2021, 188–218
ER -
TY - CHAP
AU - Ptashnyk, Stefaniya
ED - Glaser, Elvira
ED - Prinz, Michael
ED - Ptashnyk, Stefaniya
ID - 32199
T2 - Historisches Codeswitching mit Deutsch. Multilinguale Praktiken in der Sprachge-schichte
TI - Codeswitching und seine „Geschwister“. Zur Typologie der historischen multilingualen Schreibpraktiken (am Beispiel der Lemberger Zeitungen des 19. Jahrhunderts)
ER -
TY - CHAP
AU - Ptashnyk, Stefaniya
ED - Glaser, Elvira
ED - Prinz, Michael
ED - Ptashnyk, Stefaniya
ID - 32192
T2 - Historisches Codeswitching mit Deutsch
TI - Multilinguale Praktiken in der Sprachgeschich-te
ER -
TY - CHAP
AU - Ptashnyk, Stefaniya
AU - Glaser, Elvira
AU - Prinz, Michael
ED - Glaser, Elvira
ED - Prinz, Michael
ED - Ptashnyk, Stefaniya
ID - 32200
T2 - Historisches Codeswitching mit Deutsch. Multilinguale Praktiken in der Sprachgeschichte
TI - Historisches Codeswitching mit Deutsch: Eine Einleitung
ER -
TY - JOUR
AB - Abstract
The defining feature of active particles is that they constantly propel themselves by locally converting chemical energy into directed motion. This active self-propulsion prevents them from equilibrating with their thermal environment (e.g. an aqueous solution), thus keeping them permanently out of equilibrium. Nevertheless, the spatial dynamics of active particles might share certain equilibrium features, in particular in the steady state. We here focus on the time-reversal symmetry of individual spatial trajectories as a distinct equilibrium characteristic. We investigate to what extent the steady-state trajectories of a trapped active particle obey or break this time-reversal symmetry. Within the framework of active Ornstein–Uhlenbeck particles we find that the steady-state trajectories in a harmonic potential fulfill path-wise time-reversal symmetry exactly, while this symmetry is typically broken in anharmonic potentials.
AU - Dabelow, Lennart
AU - Bo, Stefano
AU - Eichhorn, Ralf
ID - 32243
IS - 3
JF - Journal of Statistical Mechanics: Theory and Experiment
KW - Statistics
KW - Probability and Uncertainty
KW - Statistics and Probability
KW - Statistical and Nonlinear Physics
SN - 1742-5468
TI - How irreversible are steady-state trajectories of a trapped active particle?
VL - 2021
ER -
TY - GEN
AB - We push the boundaries of electronic structure-based \textit{ab-initio}
molecular dynamics (AIMD) beyond 100 million atoms. This scale is otherwise
barely reachable with classical force-field methods or novel neural network and
machine learning potentials. We achieve this breakthrough by combining
innovations in linear-scaling AIMD, efficient and approximate sparse linear
algebra, low and mixed-precision floating-point computation on GPUs, and a
compensation scheme for the errors introduced by numerical approximations. The
core of our work is the non-orthogonalized local submatrix method (NOLSM),
which scales very favorably to massively parallel computing systems and
translates large sparse matrix operations into highly parallel, dense matrix
operations that are ideally suited to hardware accelerators. We demonstrate
that the NOLSM method, which is at the center point of each AIMD step, is able
to achieve a sustained performance of 324 PFLOP/s in mixed FP16/FP32 precision
corresponding to an efficiency of 67.7% when running on 1536 NVIDIA A100 GPUs.
AU - Schade, Robert
AU - Kenter, Tobias
AU - Elgabarty, Hossam
AU - Lass, Michael
AU - Schütt, Ole
AU - Lazzaro, Alfio
AU - Pabst, Hans
AU - Mohr, Stephan
AU - Hutter, Jürg
AU - Kühne, Thomas D.
AU - Plessl, Christian
ID - 32244
T2 - arXiv:2104.08245
TI - Towards Electronic Structure-Based Ab-Initio Molecular Dynamics Simulations with Hundreds of Millions of Atoms
ER -
TY - GEN
AB - Optical travelling wave antennas offer unique opportunities to control and
selectively guide light into a specific direction which renders them as
excellent candidates for optical communication and sensing. These applications
require state of the art engineering to reach optimized functionalities such as
high directivity and radiation efficiency, low side lobe level, broadband and
tunable capabilities, and compact design. In this work we report on the
numerical optimization of the directivity of optical travelling wave antennas
made from low-loss dielectric materials using full-wave numerical simulations
in conjunction with a particle swarm optimization algorithm. The antennas are
composed of a reflector and a director deposited on a glass substrate and an
emitter placed in the feed gap between them serves as an internal source of
excitation. In particular, we analysed antennas with rectangular- and
horn-shaped directors made of either Hafnium dioxide or Silicon. The optimized
antennas produce highly directional emission due to the presence of two
dominant guided TE modes in the director in addition to leaky modes. These
guided modes dominate the far-field emission pattern and govern the direction
of the main lobe emission which predominately originates from the end facet of
the director. Our work also provides a comprehensive analysis of the modes,
radiation patterns, parametric influences, and bandwidths of the antennas that
highlights their robust nature.
AU - Farheen, Henna
AU - Leuteritz, Till
AU - Linden, Stefan
AU - Myroshnychenko, Viktor
AU - Förstner, Jens
ID - 32245
T2 - arXiv:2106.02468
TI - Optimization of optical waveguide antennas for directive emission of light
ER -
TY - CHAP
AU - Ptashnyk, Stefaniya
ED - Korn, Uwe Maximillian
ED - Żarski, Krzysztof
ID - 32251
T2 - Institutionen – Praktiken – Biographien. Verankerung und Profilierung der germanis-tischen Forschung und Lehre
TI - Von der Schwierigkeit des biografischen Schreibens über Ludwik Fleck
ER -
TY - JOUR
AU - Hein-Pensel, Franziska
AU - Knorr, Karin
AU - Oertel, Simon
AU - Thommes, Kirsten
ID - 26146
JF - Academy of Management Proceedings
SN - 0065-0668
TI - Incongruent Patterns of Organizational Identity Crafting by Different Organizational Actors
ER -
TY - GEN
AU - Peckhaus, Volker
ID - 29141
T2 - Mathematical Reviews
TI - Fan, Zhao, “Hobson’s Conception of Definable Numbers”, In: History and Philosophy of Logic 41 (2020)
ER -
TY - GEN
AU - Peckhaus, Volker
ID - 29144
T2 - Mathematical Reviews
TI - Vlasáková, Marta, “Logic and Sets”, In: Logic and Logical Philosophy 29 (2020)
ER -
TY - CHAP
AB - In this study, we describe a text processing pipeline that transforms user-generated text into structured data. To do this, we train neural and transformer-based models for aspect-based sentiment analysis. As most research deals with explicit aspects from product or service data, we extract and classify implicit and explicit aspect phrases from German-language physician review texts. Patients often rate on the basis of perceived friendliness or competence. The vocabulary is difficult, the topic sensitive, and the data user-generated. The aspect phrases come with various wordings using insertions and are not noun-based, which makes the presented case equally relevant and reality-based. To find complex, indirect aspect phrases, up-to-date deep learning approaches must be combined with supervised training data. We describe three aspect phrase datasets, one of them new, as well as a newly annotated aspect polarity dataset. Alongside this, we build an algorithm to rate the aspect phrase importance. All in all, we train eight transformers on the new raw data domain, compare 54 neural aspect extraction models and, based on this, create eight aspect polarity models for our pipeline. These models are evaluated by using Precision, Recall, and F-Score measures. Finally, we evaluate our aspect phrase importance measure algorithm.
AU - Kersting, Joschka
AU - Geierhos, Michaela
ED - Kapetanios, Epaminondas
ED - Horacek, Helmut
ED - Métais, Elisabeth
ED - Meziane, Farid
ID - 22052
T2 - Natural Language Processing and Information Systems
TI - Human Language Comprehension in Aspect Phrase Extraction with Importance Weighting
VL - 12801
ER -
TY - JOUR
AB - AbstractThe interaction of acute exercise and the central nervous system evokes increasing interest in interdisciplinary research fields of neuroscience. Novel approaches allow to monitor large-scale brain networks from mobile electroencephalography (EEG) applying graph theory, but it is yet uncertain whether brain graphs extracted after exercise are reliable. We therefore aimed to investigate brain graph reliability extracted from resting state EEG data before and after submaximal exercise twice within one week in male participants. To obtain graph measures, we extracted global small-world-index (SWI), clustering coefficient (CC) and characteristic path length (PL) based on weighted phase leg index (wPLI) and spectral coherence (Coh) calculation. For reliability analysis, Intraclass-Correlation-Coefficient (ICC) and Coefficient of Variation (CoV) were computed for graph measures before (REST) and after POST) exercise. Overall results revealed poor to excellent measures at PRE and good to excellent ICCs at POST in the theta, alpha-1 and alpha-2, beta-1 and beta-2 frequency band. Based on bootstrap-analysis, a positive effect of exercise on reliability of wPLI based measures was observed, while exercise induced a negative effect on reliability of Coh-based graph measures. Findings indicate that brain graphs are a reliable tool to analyze brain networks in exercise contexts, which might be related to the neuroregulating effect of exercise inducing functional connections within the connectome. Relative and absolute reliability demonstrated good to excellent reliability after exercise. Chosen graph measures may not only allow analysis of acute, but also longitudinal studies in exercise-scientific contexts.
AU - Büchel, Daniel
AU - Lehmann, Tim
AU - Sandbakk, Øyvind
AU - Baumeister, Jochen
ID - 26719
JF - Scientific Reports
SN - 2045-2322
TI - EEG-derived brain graphs are reliable measures for exploring exercise-induced changes in brain networks
ER -
TY - GEN
AU - Ahmeckovic, Emina
ID - 24671
TI - Die Sterne sind für alle da - Eine empirische Untersuchung zu Anforderungen der Gestaltung von barrierefreien Online-Bewertungssystemen
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TY - GEN
AU - Pieper, Florian
ID - 23554
TI - Systematische Identifikation und Analyse von Vorgehensmodellen zur Geschäftsmodellentwicklung auf digitalen Plattformen
ER -
TY - GEN
AU - Funk, Daniel
ID - 24576
TI - Wer schreibt der bleibt – Eine quantitative Untersuchung der Kundenbeziehung in Brand Communities und Smart Service Systems
ER -
TY - GEN
AU - Rümpker, Till
ID - 25181
TI - Wechselwirkungen von Hemmnissen und Motivatoren mit Blick auf die Abgabe von Online-Bewertungen
ER -
TY - GEN
AU - Roslan, Jan-Philipp
ID - 24685
TI - Mitten ins Herz – Eine semantische Analyse von Spendenkampagnen auf Crowdfunding Plattformen
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TY - GEN
AU - Speer, Laura
ID - 24577
TI - Digitale Diskriminierung – Ein systematischer Literaturüberblick
ER -