TY - GEN
AU - N., N.
ID - 46221
TI - Improving the End-of-Line Test of Custom-Built Geared Motors using Clustering based on Neural Networks
ER -
TY - JOUR
AU - Demir, Caglar
AU - Ngonga Ngomo, Axel-Cyrille
ID - 46243
JF - ECML-PKDD
TI - Clifford Embeddings – A Generalized Approach for Embedding in Normed Algebras
ER -
TY - JOUR
AU - Demir, Caglar
AU - Ngonga Ngomo, Axel-Cyrille
ID - 46251
JF - International Joint Conference on Artificial Intelligence
TI - Neuro-Symbolic Class Expression Learning
ER -
TY - JOUR
AU - Ma, Yulai
AU - Mattiolo, Davide
AU - Steffen, Eckhard
AU - Wolf, Isaak Hieronymus
ID - 46256
IS - 3
JF - SIAM Journal on Discrete Mathematics
KW - General Mathematics
SN - 0895-4801
TI - Pairwise Disjoint Perfect Matchings in r-Edge-Connected r-Regular Graphs
VL - 37
ER -
TY - CONF
AU - Meier, Jana
AU - Vogelsang, Christoph
AU - Küth, Simon
AU - Scholl , Daniel
AU - Watson, Christina
AU - Seifert, Andreas
ID - 46261
TI - Welche Rolle spielt eine reflexive Haltung für eine qualitätsvolle Unterrichtsreflexion? – Zusammenhänge zwischen einer quasi-experimentellen Einstellung und der Reflexionsperformanz von Lehramtsstudierenden [Einzelbeitrag].
ER -
TY - CONF
AU - Scholl, Daniel
AU - Küth, Simon
AU - Vogelsang, Christoph
AU - Meier, Jana
AU - Watson, Christina
AU - Seifert, Andreas
ID - 46262
TI - Das Unterrichtsplanungsprinzip der Interdependenz – Eine netzwerkanalytische Untersuchung der Begründungsstrukturen beim Planungsentscheiden [Einzelbeitrag].
ER -
TY - CONF
AU - Scholl, Daniel
AU - Vogelsang, Christoph
AU - Küth, Simon
AU - Meier, Jana
AU - Watson, Christina
AU - Seifert, Andreas
ID - 46263
TI - Eine reflexive Haltung als Grundlage einer hochwertigen Unterrichtsreflexion? Zusammenhänge zwischen einer quasi-experimentellen Einstellung zur Reflexion und der Reflexionsperformanz von Lehramtsstudierenden [Einzelbeitrag].
ER -
TY - GEN
ED - Meier, Jana
ED - Küth, Simon
ED - Scholl , Daniel
ED - Vogelsang, Christoph
ED - Watson, Christina
ID - 46260
TI - Der Zyklus von Planung und Reflexion. Zusammenhänge zwischen der generischen Unterrichtsplanungsfähigkeit und der Reflexionskompetenz angehender Lehrkräfte.
ER -
TY - CONF
AB - State-of-the-art LLC resonant converters use MOSFETs in their inverter stage, which allows high switching frequencies and thus the use of compact magnetic components. The large parasitic output capacitance and the poor reverse-recovery behaviour of the inherent body diode of high-voltage (600 V) silicon MOSFETs require soft switching, i.e. zero-voltage switching (ZVS). Otherwise, the high turn-on switching losses would lead to excessive heating and ultimately to the destruction of the switch. Therefore, MOSFET-based LLC converters are operated in the so-called inductive region only, which enables ZVS. The use of robust and cost-effective IGBTs instead of MOSFETs is particularly advantageous for automotive applications, since in addition to high reliability low costs are an important objective here. Since IGBTs are characterized by dominant turn-off losses and generally higher switching losses compared to MOSFETs, the aim is to operate them with zero-current switching (ZCS) and at low switching frequencies below the resonance frequency. In this region also the voltage transfer characteristic is steeper, which qualifies for applications with a strongly varying input-to-output voltage ratio, such as given for automotive on-board DC-DC converters connecting the (high-voltage) traction battery with the (12 V) auxiliary battery. In this paper, a stress value analysis based on a switched-model simulation is used to design a ZCS LLC converter and take advantage of the mentioned benefits of IGBTs as well as of the steeper voltage transfer characteristic. Within this operation region below the resonance frequency, however, a new phenomenon of several current pulses occurring during a single switching period through the rectifier components may appear. Generally, in applications with high output currents a synchronous rectifier (SR) is often used to keep the conduction losses of the rectifier stage at a moderate level: Low-voltage MOSFETs, which actively need to be gated synchronously to the polarity of the current pulses, are employed then instead of more lossy rectifier diodes. However, standard SR driver ICs have been shown to be unable to properly rectify the multi-pulse output currents of the proposed LLC operation, resulting in high conduction losses of the rectifier stage. A cost-effective hardware concept is presented which ensures proper rectification by using standard SR-ICs that are actively overdriven by the converter’s central microcontroller. A 2 kW prototype for an EV on-board DC-DC converter was built to show the effectiveness of the method, documenting an increase in efficiency by up to 4.1 % compared to a purely SR-IC-based solution. Overall efficiency is very similar to that of a conventional (MOSFET-based) LLC converter so that the ZCS-operated LLC IGBT-converter represents a cost-effective alternative, which even shows 10 % less worst-case losses.
AU - Urbaneck, Daniel
AU - Schafmeister, Frank
AU - Böcker, Joachim
ID - 46269
KW - LLC Converter
KW - IGBT
KW - ZCS
KW - Synchronous Rectification
T2 - PCIM Europe 2023
TI - Advanced Synchronous Rectification for an IGBT-Based ZCS LLC Converter with High Output Currents for a 2 kW Automotive DC-DC Stage
ER -
TY - CONF
AB - The computation of electron repulsion integrals (ERIs) over Gaussian-type orbitals (GTOs) is a challenging problem in quantum-mechanics-based atomistic simulations. In practical simulations, several trillions of ERIs may have to be
computed for every time step.
In this work, we investigate FPGAs as accelerators for the ERI computation. We use template parameters, here within the Intel oneAPI tool flow, to create customized designs for 256 different ERI quartet classes, based on their orbitals. To maximize data reuse, all intermediates are buffered in FPGA on-chip memory with customized layout. The pre-calculation of intermediates also helps to overcome data dependencies caused by multi-dimensional recurrence
relations. The involved loop structures are partially or even fully unrolled for high throughput of FPGA kernels. Furthermore, a lossy compression algorithm utilizing arbitrary bitwidth integers is integrated in the FPGA kernels. To our
best knowledge, this is the first work on ERI computation on FPGAs that supports more than just the single most basic quartet class. Also, the integration of ERI computation and compression it a novelty that is not even covered by CPU or GPU libraries so far.
Our evaluation shows that using 16-bit integer for the ERI compression, the fastest FPGA kernels exceed the performance of 10 GERIS ($10 \times 10^9$ ERIs per second) on one Intel Stratix 10 GX 2800 FPGA, with maximum absolute errors around $10^{-7}$ - $10^{-5}$ Hartree. The measured throughput can be accurately explained by a performance model. The FPGA kernels deployed on 2 FPGAs outperform similar computations using the widely used libint reference on a two-socket server with 40 Xeon Gold 6148 CPU cores of the same process technology by factors up to 6.0x and on a new two-socket server with 128 EPYC 7713 CPU cores by up to 1.9x.
AU - Wu, Xin
AU - Kenter, Tobias
AU - Schade, Robert
AU - Kühne, Thomas
AU - Plessl, Christian
ID - 43228
T2 - 2023 IEEE 31st Annual International Symposium on Field-Programmable Custom Computing Machines (FCCM)
TI - Computing and Compressing Electron Repulsion Integrals on FPGAs
ER -
TY - JOUR
AB - The non-orthogonal local submatrix method applied to electronic structure–based molecular dynamics simulations is shown to exceed 1.1 EFLOP/s in FP16/FP32-mixed floating-point arithmetic when using 4400 NVIDIA A100 GPUs of the Perlmutter system. This is enabled by a modification of the original method that pushes the sustained fraction of the peak performance to about 80%. Example calculations are performed for SARS-CoV-2 spike proteins with up to 83 million atoms.
AU - Schade, Robert
AU - Kenter, Tobias
AU - Elgabarty, Hossam
AU - Lass, Michael
AU - Kühne, Thomas
AU - Plessl, Christian
ID - 45361
JF - The International Journal of High Performance Computing Applications
KW - Hardware and Architecture
KW - Theoretical Computer Science
KW - Software
SN - 1094-3420
TI - Breaking the exascale barrier for the electronic structure problem in ab-initio molecular dynamics
ER -
TY - JOUR
AB - Site-controlled Ga droplets on AlGaAs substrates are fabricated using area-selective deposition of Ga through apertures in a mask during molecular beam epitaxy (MBE). The Ga droplets can be crystallized into GaAs quantum dots using a crystallization step under As flux. In order to model the complex process, including the masked deposition of the droplets and a reduction of their number during a thermal annealing step, a multiscale kinetic Monte Carlo (mkMC) simulation of self-assembled Ga droplet formation on AlGaAs is expanded for area-selective deposition. The simulation has only two free model parameters: the activation energy for surface diffusion and the activation energy for thermal escape of adatoms from a droplet. Simulated droplet numbers within the opening of the aperture agree quantitatively with the experimental results down to the perfect site-control, with one droplet per aperture. However, the model parameters are different compared to those of the self-assembled droplet growth. We attribute this to the presence of the mask in close proximity to the surface, which modifies the local process temperature and the As background. This approach also explains the dependence of the model parameters on the size of the aperture.
AU - Feddersen, Stefan
AU - Zolatanosha, Viktoryia
AU - Alshaikh, Ahmed
AU - Reuter, Dirk
AU - Heyn, Christian
ID - 46278
IS - 3
JF - Nanomaterials
KW - General Materials Science
KW - General Chemical Engineering
SN - 2079-4991
TI - Modeling of Masked Droplet Deposition for Site-Controlled Ga Droplets
VL - 13
ER -
TY - JOUR
AU - Sieland, Benedikt
AU - Stahn, Marcel
AU - Schoch, Roland
AU - Daniliuc, Constantin
AU - Spicher, Sebastian
AU - Grimme, Stefan
AU - Hansen, Andreas
AU - Paradies, Jan
ID - 46277
JF - Angewandte Chemie International Edition
KW - General Chemistry
KW - Catalysis
SN - 1433-7851
TI - Dispersion Energy‐Stabilized Boron and Phosphorus Lewis Pairs
ER -
TY - CONF
AU - Clausing, Lennart
AU - Guetattfi, Zakarya
AU - Kaufmann, Paul
AU - Lienen, Christian
AU - Platzner, Marco
ID - 45913
T2 - Proceedings of the 19th International Symposium on Applied Reconfigurable Computing (ARC)
TI - On Guaranteeing Schedulability of Periodic Real-time Hardware Tasks under ReconOS64
ER -
TY - CHAP
AU - Tophinke, Doris
ED - Feilke, Helmuth
ID - 46099
T2 - Zwischen Fake und Fakt
TI - "Tankrabatt" und "Freiheitsenergie". Wie der Blog "neusprech.org" politische Euphemismen entlarvt
VL - 300
ER -
TY - JOUR
AU - Merten, Marie-Luis
AU - Wever, Marcel
AU - Tophinke, Doris
AU - Geierhos, Michaela
AU - Hüllermeier, Eyke
ID - 45673
JF - International Journal of Corpus Linguistics
TI - Annotation uncertainty in the context of grammatical change
ER -
TY - THES
AU - Tornede, Alexander
ID - 45780
TI - Advanced Algorithm Selection with Machine Learning: Handling Large Algorithm Sets, Learning From Censored Data, and Simplyfing Meta Level Decisions
ER -
TY - THES
AU - Spiess-Bru, Clarissa
ID - 46296
TI - Information Asymmetry and Gendered Behavior in Organizations and Digital Markets
ER -
TY - CONF
AB - A frequency-flexible Nyquist pulse synthesizer is presented with optical pulse bandwidths up to fopt=100 GHz and repetition rates equal to fopt/9, fabricated in an electronic-photonic co-integrated platform utilizing linear on-chip drivers.
AU - Kress, Christian
AU - Schwabe, Tobias
AU - Silberhorn, Christine
AU - Scheytt, J. Christoph
ID - 45578
T2 - Conference on Lasers and Electro-Optics (CLEO) 2023
TI - Generation of 100 GHz Periodic Nyquist Pulses using Cascaded Mach-Zehnder Modulators in a Silicon Electronic-Photonic Platform
ER -
TY - JOUR
AU - Homt, Martina
AU - Bloh, Bea
ID - 46354
IS - 1
JF - Lehrerbildung auf dem Prüfstand
TI - Der formelle Diskurs Forschenden Lernens in der Lehrerbildung. Ein Blick zurück nach vorn
VL - 16
ER -
TY - CHAP
AU - Ksouri-Gerwien, Christoph
AU - Vorbohle, Christian
ED - Schallmo, D.R.A.
ED - Kundisch, Dennis
ED - Lang, K.
ID - 37704
T2 - Digitale Plattformen und Ökosysteme im B2B-Bereich
TI - Anwendung von System Dynamics zur Geschäftsmodellinnovation in einem B2B-Ökosystem
ER -
TY - CONF
AB - Effect chain modelling is a method for creating information
models for impact analyses of changes in system elements. For
the estimation of change propagation, dependencies between
requirements must be detected. The high number of require-
ment dependencies in the engineering of complex technical
systems results in the need for automation. In a study, it was
shown that transformer models (BERT) are suitable for the
automated dependency analysis of requirements. However,
there are currently deficits in the applicability of the models
for different projects without an extensive and heterogeneous
training database. This paper investigates how active learning
can be used to train BERT models (active-BERT) in order to
increase the performance of the models for classifying requi-
rement dependencies of projects with heterogeneous require-
ments. The results show that the performance of the models
increases significantly through active learning. Through active-
BERT, engineers are enabled to model effect chains efficiently
and to handle requirement changes effectively.
AU - Gräßler, Iris
AU - Preuß, Daniel
ED - Hölzle, Katharina
ED - Kreimeyer, Matthias
ED - Roth, Daniel
ED - Maier, Thomas
ED - Riedel, Oliver
ID - 45661
SN - 2364-4885
T2 - Stuttgarter Symposium für Produktentwicklung SSP 2023
TI - Automatisierte Abhängigkeitsanalyse von Anforderungen zur Wirkkettenmodellierung
ER -
TY - BOOK
AU - Fuchs, Christian
ID - 42949
SN - 9781032362724
TI - Digital Democracy and the Digital Public Sphere
VL - 6
ER -
TY - GEN
AB - Effective photoinduced charge transfer makes molecular bimetallic assemblies attractive for applications as active light induced proton reduction systems. For a more sustainable future, development of competitive base metal dyads is mandatory. However, the electron transfer mechanisms from the photosensitizer to the proton reduction catalyst in base metal dyads remain so far unexplored. We study a Fe-Co dyad that exhibits photocatalytic H2 production activity using femtosecond X-ray emission spectroscopy, complemented by ultrafast optical spectroscopy and theoretical time-dependent DFT calculations, to understand the electronic and structural dynamics after photoexcitation and during the subsequent charge transfer process from the FeII photosensitizer to the cobaloxime catalyst. Using this novel approach, the simultaneous measurement of the transient Kalpha X-ray emission at the iron and cobalt K-edges in a two-colour experiment is enabled making it possible to correlate the excited state dynamics to the electron transfer processes. The methodology, therefore, provides a clear and direct spectroscopic evidence of the Fe->Co electron transfer responsible for the proton reduction activity.
AU - Nowakowski, Michał
AU - Huber-Gedert, Marina
AU - Elgabarty, Hossam
AU - Kubicki, Jacek
AU - Kertem, Ahmet
AU - Lindner, Natalia
AU - Khakhulin, Dimitry
AU - Lima, Frederico Alves
AU - Choi, Tae-Kyu
AU - Biednov, Mykola
AU - Piergies, Natalia
AU - Zalden, Peter
AU - Kubicek, Katerina
AU - Rodriguez-Fernandez, Angel
AU - Salem, Mohammad Alaraby
AU - Kühne, Thomas
AU - Gawelda, Wojciech
AU - Bauer, Matthias
ID - 40982
T2 - arxiv
TI - Ultrafast two-colour X-ray emission spectroscopy reveals excited state landscape in a base metal dyad
ER -
TY - CONF
AB - The article shows how to learn models of dynamical systems from data which are governed by an unknown variational PDE. Rather than employing reduction techniques, we learn a discrete field theory governed by a discrete Lagrangian density $L_d$ that is modelled as a neural network. Careful regularisation of the loss function for training $L_d$ is necessary to obtain a field theory that is suitable for numerical computations: we derive a regularisation term which optimises the solvability of the discrete Euler--Lagrange equations. Secondly, we develop a method to find solutions to machine learned discrete field theories which constitute travelling waves of the underlying continuous PDE.
AU - Offen, Christian
AU - Ober-Blöbaum, Sina
ED - Nielsen, F
ED - Barbaresco, F
ID - 42163
KW - System identification
KW - discrete Lagrangians
KW - travelling waves
T2 - Geometric Science of Information
TI - Learning discrete Lagrangians for variational PDEs from data and detection of travelling waves
VL - 14071
ER -
TY - JOUR
AB - The principle of least action is one of the most fundamental physical principle. It says that among all possible motions connecting two points in a phase space, the system will exhibit those motions which extremise an action functional. Many qualitative features of dynamical systems, such as the presence of conservation laws and energy balance equations, are related to the existence of an action functional. Incorporating variational structure into learning algorithms for dynamical systems is, therefore, crucial in order to make sure that the learned model shares important features with the exact physical system. In this paper we show how to incorporate variational principles into trajectory predictions of learned dynamical systems. The novelty of this work is that (1) our technique relies only on discrete position data of observed trajectories. Velocities or conjugate momenta do not need to be observed or approximated and no prior knowledge about the form of the variational principle is assumed. Instead, they are recovered using backward error analysis. (2) Moreover, our technique compensates discretisation errors when trajectories are computed from the learned system. This is important when moderate to large step-sizes are used and high accuracy is required. For this,
we introduce and rigorously analyse the concept of inverse modified Lagrangians by developing an inverse version of variational backward error analysis. (3) Finally, we introduce a method to perform system identification from position observations only, based on variational backward error analysis.
AU - Ober-Blöbaum, Sina
AU - Offen, Christian
ID - 29240
JF - Journal of Computational and Applied Mathematics
KW - Lagrangian learning
KW - variational backward error analysis
KW - modified Lagrangian
KW - variational integrators
KW - physics informed learning
SN - 0377-0427
TI - Variational Learning of Euler–Lagrange Dynamics from Data
VL - 421
ER -
TY - JOUR
AB - The numerical solution of an ordinary differential equation can be interpreted as the exact solution of a nearby modified equation. Investigating the behaviour of numerical solutions by analysing the modified equation is known as backward error analysis. If the original and modified equation share structural properties, then the exact and approximate solution share geometric features such as the existence of conserved quantities. Conjugate symplectic methods preserve a modified symplectic form and a modified Hamiltonian when applied to a Hamiltonian system. We show how a blended version of variational and symplectic techniques can be used to compute modified symplectic and Hamiltonian structures. In contrast to other approaches, our backward error analysis method does not rely on an ansatz but computes the structures systematically, provided that a variational formulation of the method is known. The technique is illustrated on the example of symmetric linear multistep methods with matrix coefficients.
AU - McLachlan, Robert
AU - Offen, Christian
ID - 29236
IS - 1
JF - Journal of Geometric Mechanics
KW - variational integrators
KW - backward error analysis
KW - Euler--Lagrange equations
KW - multistep methods
KW - conjugate symplectic methods
TI - Backward error analysis for conjugate symplectic methods
VL - 15
ER -
TY - JOUR
AB - Recently, Hamiltonian neural networks (HNN) have been introduced to incorporate prior physical knowledge when
learning the dynamical equations of Hamiltonian systems. Hereby, the symplectic system structure is preserved despite
the data-driven modeling approach. However, preserving symmetries requires additional attention. In this research, we
enhance the HNN with a Lie algebra framework to detect and embed symmetries in the neural network. This approach
allows to simultaneously learn the symmetry group action and the total energy of the system. As illustrating examples,
a pendulum on a cart and a two-body problem from astrodynamics are considered.
AU - Dierkes, Eva
AU - Offen, Christian
AU - Ober-Blöbaum, Sina
AU - Flaßkamp, Kathrin
ID - 37654
IS - 6
JF - Chaos
SN - 1054-1500
TI - Hamiltonian Neural Networks with Automatic Symmetry Detection
VL - 33
ER -
TY - CHAP
AU - Dehmel, Lukas
ED - Kondratjuk, Maria
ID - 46473
T2 - Grundlagen der Erwachsenen- und Weiterbildungsforschung
TI - 6.3.2 Medienpädagogische Professionalisierung in der beruflichen Weiterbildung. Eine Studie aus Perspektive der biografischen Medienforschung. Steckbrief zur Dissertation.
ER -
TY - JOUR
AU - Unterstell, Rembert
ID - 46471
IS - 1
JF - german research – Magazine of the Deutsche Forschungsgemeinschaft
TI - „Allowing the Economy to Breathe Even During the Crisis“ – Interview with Tax Expert Caren Sureth-Sloane
ER -
TY - GEN
ED - Ade, Larissa
ED - Breiwe, René
ED - Dehmel, Lukas
ED - Wolf, Karsten D.
ED - Rummler, Klaus
ED - Dander, Valentin
ED - Grünberger, Nina
ED - Schiefner-Rohs, Mandy
ID - 46474
IS - 53
TI - ENT | GRENZ | UNGEN in der Medienpädagogik. Perspektiven im Anschluss an den 28. Kongress der DGfE
ER -
TY - JOUR
AU - Dehmel, Lukas
AU - Meister, Dorothee
AU - Gerhardts, Lara
ID - 46472
IS - 53
JF - Zeitschrift MedienPädagogik
TI - Die Entgrenzung von Kommunikationskulturen in Lehrpersonenkollegien. Reflexion einer unbeabsichtigten Begleiterscheinung der Arbeit mit Tablets.
ER -
TY - CHAP
AB - Dieser Beitrag bietet verschiedene professionelle Perspektiven auf den popmusikalischen Kommunikationsprozesses innerhalb postdigitaler Popmusikjournalismuskulturen. Neben einer wissenschaftlichen Rahmung, Übersicht und Strukturierung des Untersuchungsfelds und des Forschungsstands versammelt der Beitrag multiperspektivische Thesen, die journalistische Praktiken und ihre Reflexionen von Produktion über Distribution und Rezeption/Nutzung bis zur Weiterverarbeitung inklusive Archivierung/Institutionalisierung/Musealisierung aufgreifen und herausstellen. Die aufgestellten Thesen gelten als Aufschlag für die zukünftige Analyse des so fundamentalen und doch auch immer wieder übersehenen Berufsfeldes und seiner Rezeption zwischen Faszination und Exploitation.
AU - Godlewsky, Tanja
AU - Jacke, Christoph
AU - Roenneke, Stefanie
AU - Venker, Thomas
ED - Moormann, Peter
ED - Ruth, Nicolas
ID - 46475
SN - 2626-6199
T2 - Musik und Internet. Aktuelle Phänomene populärer Kulturen
TI - Pop(musik)journalismen zwischen Printmagazin-Krise und postdigitaler Realität – Forschungsüberblick und multiperspektivische Thesen
ER -
TY - CONF
AB - Abstract. Increasing resource efficiency is a major challenge and affects almost every aspect of social and economic life. The mobility sector in particular is responsible for a large share of primary energy consumption and is increasingly in the focus of public interest. One possibility to adress these challenges is to reduce the vehicle weight by means of lightweight construction technologies such as multi-material systems. These assemblies consist of workpieces with different mechanical and geometrical properties, which poses a major challenge for joining technology. Mechanical joining processes such as semi-tubular self-piercing riveting are often used in the production of these assemblies, but due to their process characteristics, they are rigid and can only react to changing process variables to a limited extent. One way to increase the versatility of self-piercing riveting is to superimpose a tumbling kinematics on the punch. During tumbling, an angular offset of the punch axis to the tool axis is set and the contact area between punch and workpiece is reduced. In this work, investigations were carried out to determine how the tumbling strategy, consisting of the parameters tumbling angle, tumbling onset and tumbling kinematics, affects the material flow of the rivet element. For this purpose, experimental tests are conducted with the typical materials of conventional multi-material systems and the geometric joint formations are determined by means of macrographs.
AU - Wituschek, S.
AU - Elbel, L.
AU - Lechner, M.
ID - 46476
SN - 2474-395X
T2 - Materials Research Proceedings
TI - Versatile self-piercing riveting with a tumbling superimposed punch
ER -
TY - JOUR
AU - Lange, Nina Amelie
AU - Schapeler, Timon
AU - Höpker, Jan Philipp
AU - Protte, Maximilian
AU - Bartley, Tim
ID - 46468
IS - 2
JF - Physical Review A
SN - 2469-9926
TI - Degenerate photons from a cryogenic spontaneous parametric down-conversion source
VL - 108
ER -
TY - JOUR
AU - Bartelheimer, Christian
AU - zur Heiden, Philipp
AU - Berendes, Carsten Ingo
AU - Beverungen, Daniel
ID - 46478
JF - European Journal of Information Systems
KW - Library and Information Sciences
KW - Information Systems
SN - 0960-085X
TI - Designing digital actor engagement platforms for local high streets: an action design research study
ER -
TY - THES
AB - Ever increasing demands on the performance of microchips are leading to ever more complex semiconductor technologies with ever shrinking feature sizes. Complex applications with high demands on safety and reliability, such as autonomous driving, are simultaneously driving the requirements for test and diagnosis of VLSI circuits. Throughout the life cycle of a microchip, uncertainties occur that affect its timing behavior. For example, weak circuit structures, aging effects, or process variations can lead to a change in the timing behavior of the circuit. While these uncertainties do not necessarily lead to a change of the functional behavior, they can lead to a reliability problem.
With modular and hybrid compaction two test instruments are presented in this work that can be used for X-tolerant test response compaction in the built-in Faster-than-At-Speed Test (FAST) which is used to detect uncertainties in VLSI circuits. One challenge for test response compaction during FAST is the high and varying X-rate at the outputs of the circuit under test. By dividing the circuit outputs into test groups and separately compacting these test groups using stochastic compactors, the modular compaction is able to handle these high and varying X-rates.
To deal with uncertainties on logic interconnects, a method for distinguishing crosstalk and process variation is presented. In current semiconductor technologies, the number of parasitic coupling capacitances between logic interconnects is growing. These coupling capacitances can lead to crosstalk, which causes increased current flow in the logic interconnects, which in turn can lead to increased electromigration. In the presented method, delay maps describing the timing behavior of the circuit outputs at different operating points are used to train artificial neural networks which classify the tested circuits into fault-free and faulty.
AU - Sprenger, Alexander
ID - 46482
KW - Testantwortkompaktierung
KW - Prozessvariation
KW - Silicon Lifecycle Management
TI - Testinstrumente und Testdatenanalyse zur Verarbeitung von Unsicherheiten in Logikblöcken hochintegrierter Schaltungen
ER -
TY - CONF
AB - We present a miniaturized pulse shaping device that creates an arbitrary dispersion through the interaction of multiple metasurfaces on less than 2 mm3 volume. For this, a metalens and a grating-metasurface between two silver mirrors are fabricated. The grating contains further phase information to achieve the device's pulse shaping functionality.
AU - Geromel, René
AU - Georgi, Philip
AU - Protte, Maximilian
AU - Bartley, Tim
AU - Huang, Lingling
AU - Zentgraf, Thomas
ID - 46485
T2 - CLEO: Fundamental Science 2023
TI - Dispersion control with integrated plasmonic metasurfaces
ER -
TY - JOUR
AB - We present the fabrication of strain-free quantum dots in the In0.53Ga0.47As/In0.52Al0.48As-system lattice matched to InP, as future sources for single and entangled photons for long-haul fiber-based quantum communication in the optical C-band. We achieved these quantum dots by local droplet etching via InAl droplets in an In0.52Al0.48As layer and subsequent filling of the holes with In0.53Ga0.47As. Here, we present detailed investigations of the hole morphologies measured by atomic force microscopy. Statistical analysis of a set of nanoholes reveals a high degree of symmetry for nearly half of them when etched at optimized temperatures. Overgrowth with 50–150 nm In0.52Al0.48As increases their diameter and elongates the holes along the [01̄1]-direction. By systematically scanning the parameter space, we were able to fill the holes with In0.53Ga0.47As, and by capping the filled holes and performing photoluminescence measurements, we observe photoluminescence emission in the O-band up into the C-band depending on the filling height of the nanoholes.
AU - Deutsch, D.
AU - Buchholz, C.
AU - Zolatanosha, V.
AU - Jöns, K. D.
AU - Reuter, D.
ID - 44851
IS - 5
JF - AIP Advances
KW - General Physics and Astronomy
SN - 2158-3226
TI - Telecom C-band photon emission from (In,Ga)As quantum dots generated by filling nanoholes in In0.52Al0.48As layers
VL - 13
ER -
TY - JOUR
AU - Müller, Hendrik
AU - Weinberger, Christian
AU - Grundmeier, Guido
AU - de los Arcos de Pedro, Maria Teresa
ID - 46480
JF - Journal of Electron Spectroscopy and Related Phenomena
KW - Physical and Theoretical Chemistry
KW - Spectroscopy
KW - Condensed Matter Physics
KW - Atomic and Molecular Physics
KW - and Optics
KW - Radiation
KW - Electronic
KW - Optical and Magnetic Materials
SN - 0368-2048
TI - UV-enhanced environmental charge compensation in near ambient pressure XPS
VL - 264
ER -
TY - JOUR
AU - Pfeifer, Florian
AU - Knorr, Lukas
AU - Schlosser, Florian
AU - Marten, Thorsten
AU - Tröster, Thomas
ID - 46486
IS - 3
JF - Journal of Sustainable Development of Energy, Water and Environment Systems
KW - Energy Engineering and Power Technology
KW - Water Science and Technology
KW - Environmental Science (miscellaneous)
KW - Renewable Energy
KW - Sustainability and the Environment
SN - 1848-9257
TI - Ecological and Economic Feasibility of Inductive Heating for Sustainable Press Hardening Processes
VL - 11
ER -
TY - CONF
AU - Elsner, Julia
AU - Tenberge, Claudia
AU - Fechner, Sabine
ED - van Vorst, Helena
ID - 45371
T2 - Lernen, Lehren und Forschen in einer digital geprägten Welt
TI - Videoanalyse des Modellierprozesses von Grundschüler*innen
VL - 43
ER -
TY - GEN
AU - Kundisch, Dennis
ID - 46491
TI - #DIGITALENTS - Digital Talents Programm geht in die zweite Runde
VL - 1
ER -
TY - JOUR
AU - Kempkes, J. P.
AU - Kreuzhage, K.
AU - Kundisch, Dennis
AU - Seutter, Janina
AU - Weskamp, Christoph
ID - 45656
JF - Kultur Management Network Magazin
TI - Digitale Transformation im Theater – Mittels Besucherforschung und Entscheidungsunterstützung zur besseren Angebotsgestaltung
VL - 172
ER -
TY - CONF
AU - Gräßler, Iris
AU - Wiechel, Dominik
ID - 46502
T2 - 2023 18th Annual System of Systems Engineering Conference (SoSe)
TI - Customized impact analyses for technical engineering changes
ER -
TY - JOUR
AB -
Purpose
The purpose of this study is to investigate the manufacturability of Fe-3Si lattice structures and the resulting mechanical properties. This study could lead to the successful processing of squirrel cage conductors (a lattice structure by design) of an induction motor by additive manufacturing in the future.
Design/methodology/approach
The compression behaviour of two lattice structures where struts are arranged in a face-centred cubic position and vertical edges (FCCZ), and struts are placed at body-centred cubic (BCC) positions, prepared by laser powder bed fusion (LPBF), is explored. The experimental investigations are supported by finite element method (FEM) simulations.
Findings
The FCCZ lattice structure presents a peak in the stress-strain curve, whereas the BCC lattice structure manifests a plateau. The vertical struts aligned along the compression direction lead to a significant increase in the load-carrying ability of FCCZ lattice structures compared to BCC lattice structures. This results in a peak in the stress-strain curve. However, the BCC lattice structure presents the bending of struts with diagonal struts carrying the major loads with struts near the faceplate receiving the least load. A high concentration of geometrically necessary dislocations (GNDs) near the grain boundaries along cell formation is observed in the microstructure.
Originality/value
To the best of the authors’ knowledge, this is the first study on additive manufacturing of Fe-3Si lattice structures. Currently, there are no investigations in the literature on the manufacturability and mechanical properties of Fe-3Si lattice structures.
AU - Pramanik, Sudipta
AU - Hoyer, Kay-Peter
AU - Schaper, Mirko
ID - 46503
IS - 6
JF - Rapid Prototyping Journal
KW - Industrial and Manufacturing Engineering
KW - Mechanical Engineering
SN - 1355-2546
TI - Experimental and finite element method investigation on the compression behaviour of FCCZ and BCC lattice structures of additively manufactured Fe-3Si samples
VL - 29
ER -
TY - JOUR
AU - Pramanik, Sudipta
AU - Milaege, Dennis
AU - Hein, Maxwell
AU - Andreiev, Anatolii
AU - Schaper, Mirko
AU - Hoyer, Kay-Peter
ID - 46507
IS - 14
JF - Advanced Engineering Materials
KW - Condensed Matter Physics
KW - General Materials Science
SN - 1438-1656
TI - An Experimental and Computational Modeling Study on Additively Manufactured Micro‐Architectured Ti–24Nb–4Zr–8Sn Hollow‐Strut Lattice Structures
VL - 25
ER -
TY - GEN
AU - Andreiev, Anatolii
AU - Hoyer, Kay-Peter
AU - Hengsbach, Florian
AU - Haase, Michael
AU - Schaper, Mirko
ID - 46504
TI - Powder Bed Fusion of Soft-Magnetic Iron-Silicon-Based Alloys: Advantages and Challenges
ER -
TY - CONF
AB - Purpose: Data integration and applications across knowledge graphs (KGs) rely heavily on the discovery of links between resources within these KGs. Geospatial link discovery algorithms have to deal with millions of point sets containing billions of points.
Methodology: To speed up the discovery of geospatial links, we propose COBALT. COBALT combines the content measures with R-tree indexing. The content measures are based on the area, diagonal and distance of the minimum bounding boxes of the polygons which speeds up the process but is not perfectly accurate. We thus propose two polygon splitting approaches for improving the accuracy of COBALT.
Findings: Our experiments on real-world datasets show that COBALT is able to speed up the topological relation discovery over geospatial KGs by up to 1.47 × 104 times over state-of-the-art linking algorithms while maintaining an F-Measure between 0.7 and 0.9 depending on the relation. Furthermore, we were able to achieve an F-Measure of up to 0.99 by applying our polygon splitting approaches before applying the content measures.
Value: The process of discovering links between geospatial resources can be significantly faster by sacrificing the optimality of the results. This is especially important for real time data-driven applications such as emergency response, location-based services and traffic management. In future work, additional measures, like the location of polygons or the name of the entity represented by the polygon, could be integrated to further improve the accuracy of the results.
AU - Becker, Alexander
AU - Ahmed, Abdullah Fathi Ahmed
AU - Sherif, Mohamed
AU - Ngonga Ngomo, Axel-Cyrille
ID - 46514
KW - ahmed becker dice ngonga sail sherif
T2 - SEMANTiCS
TI - COBALT: A Content-Based Similarity Approach for Link Discovery over Geospatial Knowledge Graphs
ER -
TY - JOUR
AU - Ahmed, Abdullah Fathi
AU - Sherif, Mohamed Ahmed
AU - Ngomo, Axel-Cyrille Ngonga
ID - 46517
JF - IEEE Access
KW - General Engineering
KW - General Materials Science
KW - General Computer Science
KW - Electrical and Electronic Engineering
SN - 2169-3536
TI - NELLIE: Never-Ending Linking for Linked Open Data
ER -
TY - CHAP
AB - Linked knowledge graphs build the backbone of many data-driven applications such as search engines, conversational agents and e-commerce solutions. Declarative link discovery frameworks use complex link specifications to express the conditions under which a link between two resources can be deemed to exist. However, understanding such complex link specifications is a challenging task for non-expert users of link discovery frameworks. In this paper, we address this drawback by devising NMV-LS, a language model-based verbalization approach for translating complex link specifications into natural language. NMV-LS relies on the results of rule-based link specification verbalization to apply continuous training on T5, a large language model based on the Transformerarchitecture. We evaluated NMV-LS on English and German datasets using well-known machine translation metrics such as BLUE, METEOR, ChrF++ and TER. Our results suggest that our approach achieves a verbalization performance close to that of humans and outperforms state of the art approaches. Our source code and datasets are publicly available at https://github.com/dice-group/NMV-LS.
AU - Ahmed, Abdullah Fathi Ahmed
AU - Firmansyah, Asep Fajar
AU - Sherif, Mohamed
AU - Moussallem, Diego
AU - Ngonga Ngomo, Axel-Cyrille
ID - 46516
SN - 0302-9743
T2 - Natural Language Processing and Information Systems
TI - Explainable Integration of Knowledge Graphs Using Large Language Models
ER -
TY - CONF
AU - Vogelsang, Christoph
AU - Janzen, Thomas
AU - Meier, Jana
AU - Wotschel, Philipp
ID - 46522
TI - „Die Prüfungen werden mich sicherlich nicht zu einer besseren Lehrkraft machen.“ Wie beurteilen Studierende Prüfungen und Feedback im Lehramtsstudium?
ER -
TY - CONF
AU - Wotschel, Philipp
AU - Vogelsang, Christoph
AU - Janzen, Thomas
AU - Meier, Jana
ID - 46524
TI - Als Lehrkraft gut beraten? Entwicklung und Erprobung eines handlungsnahen Prüfungsformates zur Erfassung von Beratungskompetenz von Lehramtsstudierenden
ER -
TY - CONF
AB - Purpose: This study addresses the limitations of current short abstracts of DBpedia entities, which often lack a comprehensive overview due to their creating method (i.e., selecting the first two-three sentences from the full DBpedia abstracts).
Methodology: We leverage pre-trained language models to generate abstractive summaries of DBpedia abstracts in six languages (English, French, German, Italian, Spanish, and Dutch). We performed several experiments to assess the quality of generated summaries by language models. In particular, we evaluated the generated summaries using human judgments and automated metrics (Self-ROUGE and BERTScore). Additionally, we studied the correlation between human judgments and automated metrics in evaluating the generated summaries under different aspects: informativeness, coherence, conciseness, and fluency.
Findings: Pre-trained language models generate summaries more concise and informative than existing short abstracts. Specifically, BART-based models effectively overcome the limitations of DBpedia short abstracts, especially for longer ones.
Moreover, we show that BERTScore and ROUGE-1 are reliable metrics for assessing the informativeness and coherence of the generated summaries with respect to the full DBpedia abstracts. We also find a negative correlation between conciseness and human ratings. Furthermore, fluency evaluation remains challenging without human judgment.
Value: This study has significant implications for various applications in machine learning and natural language processing that rely on DBpedia resources. By providing succinct and comprehensive summaries, our approach enhances the quality of DBpedia abstracts and contributes to the semantic web community
AU - Zahera, Hamada Mohamed Abdelsamee
AU - Vitiugin, Fedor
AU - Sherif, Mohamed
AU - Castillo, Carlos
AU - Ngonga Ngomo, Axel-Cyrille
ID - 46518
KW - dice enexa kiam ngonga porque sherif zahera
T2 - SEMANTiCS
TI - Using Pre-trained Language Models for Abstractive DBpedia Summarization: A Comparative Study
ER -
TY - DATA
AB - Graffiti is an urban phenomenon that is increasingly attracting the interest of the sciences. To the best of our knowledge, no suitable data corpora are available for systematic research until now. The Information System Graffiti in Germany project (Ingrid) closes this gap by dealing with graffiti image collections that have been made available to the project for public use. Within Ingrid, the graffiti images are collected, digitized and annotated. With this work, we aim to support the rapid access to a comprehensive data source on Ingrid targeted especially by researchers. In particular, we present IngridKG, an RDF knowledge graph of annotated graffiti, abides by the Linked Data and FAIR principles. We weekly update IngridKG by augmenting the new annotated graffiti to our knowledge graph. Our generation pipeline applies RDF data conversion, link discovery and data fusion approaches to the original data. The current version of IngridKG contains 460,640,154 triples and is linked to 3 other knowledge graphs by over 200,000 links. In our use case studies, we demonstrate the usefulness of our knowledge graph for different applications.
AU - Sherif, Mohamed
AU - Morim da Silva, Ana Alexandra
AU - Pestryakova, Svetlana
AU - Ahmed, Abdullah Fathi Ahmed
AU - Niemann, Sven
AU - Ngonga Ngomo, Axel-Cyrille
ID - 45558
TI - IngridKG: A FAIR Knowledge Graph of Graffiti
ER -
TY - JOUR
AB - Multiprotein adsorption from complex body fluids represents a highly important and complicated phenomenon in medicine. In this work, multiprotein adsorption from diluted human serum at gold and oxidized iron surfaces is investigated at different serum concentrations and pH values. Adsorption-induced changes in surface topography and the total amount of adsorbed proteins are quantified by atomic force microscopy (AFM) and polarization-modulation infrared reflection absorption spectroscopy (PM-IRRAS), respectively. For both surfaces, stronger protein adsorption is observed at pH 6 compared to pH 7 and pH 8. PM-IRRAS furthermore provides some qualitative insights into the pH-dependent alterations in the composition of the adsorbed multiprotein films. Changes in the amide II/amide I band area ratio and in particular side-chain IR absorption suggest that the increased adsorption at pH 6 is accompanied by a change in protein film composition. Presumably, this is mostly driven by the adsorption of human serum albumin, which at pH 6 adsorbs more readily and thereby replaces other proteins with lower surface affinities in the resulting multiprotein film.
AU - Huang, Jingyuan
AU - Qiu, Yunshu
AU - Lücke, Felix
AU - Su, Jiangling
AU - Grundmeier, Guido
AU - Keller, Adrian
ID - 46542
IS - 16
JF - Molecules
KW - Chemistry (miscellaneous)
KW - Analytical Chemistry
KW - Organic Chemistry
KW - Physical and Theoretical Chemistry
KW - Molecular Medicine
KW - Drug Discovery
KW - Pharmaceutical Science
SN - 1420-3049
TI - Multiprotein Adsorption from Human Serum at Gold and Oxidized Iron Surfaces Studied by Atomic Force Microscopy and Polarization-Modulation Infrared Reflection Absorption Spectroscopy
VL - 28
ER -
TY - JOUR
AB - The influence of nanoscale surface topography on protein adsorption is highly important for numerous applications in medicine and technology. Herein, ferritin adsorption at flat and nanofaceted, single-crystalline Al2O3 surfaces is investigated using atomic force microscopy and X-ray photoelectron spectroscopy. The nanofaceted surfaces are generated by the thermal annealing of Al2O3 wafers at temperatures above 1000 °C, which leads to the formation of faceted saw-tooth-like surface topographies with periodicities of about 160 nm and amplitudes of about 15 nm. Ferritin adsorption at these nanofaceted surfaces is notably suppressed compared to the flat surface at a concentration of 10 mg/mL, which is attributed to lower adsorption affinities of the newly formed facets. Consequently, adsorption is restricted mostly to the pattern grooves, where the proteins can maximize their contact area with the surface. However, this effect depends on the protein concentration, with an inverse trend being observed at 30 mg/mL. Furthermore, different ferritin adsorption behavior is observed at topographically similar nanofacet patterns fabricated at different annealing temperatures and attributed to different step and kink densities. These results demonstrate that while protein adsorption at solid surfaces can be notably affected by nanofacet patterns, fine-tuning protein adsorption in this way requires the precise control of facet properties.
AU - Pothineni, Bhanu K.
AU - Kollmann, Sabrina
AU - Li, Xinyang
AU - Grundmeier, Guido
AU - Erb, Denise J.
AU - Keller, Adrian
ID - 46543
IS - 16
JF - International Journal of Molecular Sciences
KW - Inorganic Chemistry
KW - Organic Chemistry
KW - Physical and Theoretical Chemistry
KW - Computer Science Applications
KW - Spectroscopy
KW - Molecular Biology
KW - General Medicine
KW - Catalysis
SN - 1422-0067
TI - Adsorption of Ferritin at Nanofaceted Al2O3 Surfaces
VL - 24
ER -
TY - CONF
AU - Kouagou, N’Dah Jean
AU - Heindorf, Stefan
AU - Demir, Caglar
AU - Ngomo, Axel-Cyrille Ngonga
ID - 46459
T2 - NeSy
TI - Neural Class Expression Synthesis (Extended Abstract)
VL - 3432
ER -
TY - CHAP
AB - Indonesian is classified as underrepresented in the Natural Language Processing (NLP) field, despite being the tenth most spoken language in the world with 198 million speakers. The paucity of datasets is recognized as the main reason for the slow advancements in NLP research for underrepresented languages. Significant attempts were made in 2020 to address this drawback for Indonesian. The Indonesian Natural Language Understanding (IndoNLU) benchmark was introduced alongside IndoBERT pre-trained language model. The second benchmark, Indonesian Language Evaluation Montage (IndoLEM), was presented in the same year. These benchmarks support several tasks, including Named Entity Recognition (NER). However, all NER datasets are in the public domain and do not contain domain-specific datasets. To alleviate this drawback, we introduce IndQNER, a manually annotated NER benchmark dataset in the religious domain that adheres to a meticulously designed annotation guideline. Since Indonesia has the world’s largest Muslim population, we build the dataset from the Indonesian translation of the Quran. The dataset includes 2475 named entities representing 18 different classes. To assess the annotation quality of IndQNER, we perform experiments with BiLSTM and CRF-based NER, as well as IndoBERT fine-tuning. The results reveal that the first model outperforms the second model achieving 0.98 F1 points. This outcome indicates that IndQNER may be an acceptable evaluation metric for Indonesian NER tasks in the aforementioned domain, widening the research’s domain range.
AU - Gusmita, Ria Hari
AU - Firmansyah, Asep Fajar
AU - Moussallem, Diego
AU - Ngonga Ngomo, Axel-Cyrille
ID - 46572
SN - 0302-9743
T2 - Natural Language Processing and Information Systems
TI - IndQNER: Named Entity Recognition Benchmark Dataset from the Indonesian Translation of the Quran
ER -
TY - JOUR
AB - AbstractExternal visualization (i.e., physically embodied visualization) is central to the teaching and learning of mathematics. As external visualization is an important part of mathematics at all levels of education, it is diverse, and research on external visualization has become a wide and complex field. The aim of this scoping review is to characterize external visualizations in recent mathematics education research in order to develop a common ground and guide future research. A qualitative content analysis of the full texts of 130 studies published between 2018 and 2022 applied a deductive-inductive coding procedure to assess four dimensions: visualization product or process, type of visualization, media, and purpose. The analysis revealed different types of external visualizations including visualizations with physical resemblance ranging from pictorial to abstract visualizations as well as three types of visualizations with structural resemblance: length, area, and relational visualizations. Future research should include measures of visualization products or processes to help explain the demands and affordances that different types of visualizations present to learners and teachers.
AU - Schoenherr, Johanna
AU - Schukajlow, Stanislaw
ID - 46569
JF - ZDM – Mathematics Education
KW - General Mathematics
KW - Education
SN - 1863-9690
TI - Characterizing external visualization in mathematics education research: a scoping review
ER -
TY - CHAP
AU - Vochatzer, Stefanie
ED - Bentz , Julia
ID - 46560
T2 - Creative Approaches to Climate and Peace Education. An Educationr’s Guide to Using Storytelling and Art
TI - My first contact with the Foodsharing Initiative
ER -
TY - GEN
AB - We study the effect of education on health (hospital stays, number of diagnosed conditions, self-rated poor health, and obesity) over the life-cycle in Germany, using compulsory schooling reforms as a source of exogenous variation. Our results suggest a positive correlation of health and education which increases over the life-cycle. We do not, however, find any positive local average treatment effects of an additional year of schooling on health or health care utilization for individuals up to age 79. An exception is obesity, where positive effects of schooling start to be visible around age 60 and become very large in age group 75-79. The results in age group 75-79 need to be interpreted with caution, however, due to small sample size and possible problems of attrition.
AU - Schmitz, Hendrik
AU - Tawiah, Beatrice Baaba
ID - 46534
KW - Education
KW - health
KW - life-cycle effects
KW - compulsory schooling
TI - Life-cycle health effects of compulsory schooling
VL - 1006
ER -
TY - CONF
AU - Baci, Alkid
AU - Heindorf, Stefan
ID - 46575
T2 - CIKM
TI - Accelerating Concept Learning via Sampling
ER -
TY - GEN
AU - Freise, Diana
AU - Schiele, Valentin
AU - Schmitz, Hendrik
ID - 46521
KW - General Earth and Planetary Sciences
KW - General Environmental Science
SN - 1556-5068
TI - Housing Situations and Local COVID-19 Infection Dynamics – A Case Study With Small-Area Data
ER -
TY - GEN
AB - The Koopman operator has become an essential tool for data-driven analysis, prediction and control of complex systems, the main reason being the enormous potential of identifying linear function space representations of nonlinear
dynamics from measurements. Until now, the situation where for large-scale systems, we (i) only have access to partial observations (i.e., measurements, as is very common for experimental data) or (ii) deliberately perform coarse
graining (for efficiency reasons) has not been treated to its full extent. In this paper, we address the pitfall associated with this situation, that the classical EDMD algorithm does not automatically provide a Koopman operator approximation for the underlying system if we do not carefully select the number of observables. Moreover, we show that symmetries in the system dynamics can be carried over to the Koopman operator, which allows us to massively increase the model efficiency. We also briefly draw a connection to domain decomposition techniques for partial differential equations and present numerical evidence using the Kuramoto--Sivashinsky equation.
AU - Peitz, Sebastian
AU - Harder, Hans
AU - Nüske, Feliks
AU - Philipp, Friedrich
AU - Schaller, Manuel
AU - Worthmann, Karl
ID - 46579
T2 - arXiv:2307.15325
TI - Partial observations, coarse graining and equivariance in Koopman operator theory for large-scale dynamical systems
ER -
TY - GEN
AB - We study the effect of education on vaccination against COVID-19 and influenza in Germany and Europe. Our identification strategy makes use of changes in compulsory schooling laws and allows to estimate local average treatment effects for individuals between 59 and 91 years of age. We find no significant effect of an additional year of schooling on vaccination status in Germany. Pooling data from Europe, we conclude that schooling increases the likelihood to vaccinate against COVID by an economically negligible effect of one percentage point (zero for influenza). However, we find indications that additional schooling increases fear of side effects from COVID vaccination.
AU - Monsees, Daniel
AU - Schmitz, Hendrik
ID - 46536
KW - COVID
KW - influenza
KW - vaccination
KW - education
KW - compulsory schooling
TI - The effect of compulsory schooling on vaccination against COVID and Influenza
VL - 1011
ER -
TY - CONF
AB - One of the main challenges for next generation automotive radars is the improvement of angular resolution to a sub-degree level. In this context, wide aperture automotive radars of 1m length or more and resolution close to 0.1° in azimuth and 0.5° in elevation could be beneficial. To enable coherent processing of arrays with such large aperture, prior (i.e offline) and online calibration are necessary: channel imbalances (gains and phases) and three dimensional coordinates of transmit and receive elements need to be determined. We propose a calibration strategy based on alternating steps between the two subtasks of i) channel imbalance estimation with ‘known’ array positions, by applying a singular value decomposition to the resulting tensor calculus problem; and ii) antenna position estimation with ’known’ channel imbalances, by numerically maximizing the Bayesian posterior probability; in both cases operating on range/Doppler snapshots of disjoint targets (with potentially unknown locations). Simulation studies based on the parameters of a MIMO 8x6 linear sparse array show promising results as long as the initial position errors do not exceed half a wavelength (2mm), beyond which we observe strong effects of ambiguity. Experimental results with real measurements show that after calibration in laboratory conditions, our MIMO 8x6 demonstrator with 50cm aperture is able to resolve two targets at the same range with angular separation at least as close as 0.4°.
AU - Greiff, Christian
AU - Mateos-Núñez, David
AU - Simoni, Renato
AU - González-Huici, Maria
AU - Kruse, Stephan
AU - Scheytt, J. Christoph
AU - Kolk, Karl
AU - Höller, Christian
AU - Kurz, Heiko Gustav
AU - Meinecke, Marc-Michael
AU - Gisder, Thomas
ID - 46426
T2 - 2023 24th International Radar Symposium (IRS)
TI - Calibration of Large Coherent MIMO Radar Arrays: Channel Imbalances and 3D Antenna Positions
ER -
TY - GEN
AU - Ostermann, Moritz
AU - Behm, Jonathan
AU - Marten, Thorsten
AU - Tröster, Thomas
ID - 42459
T2 - WerkstoffPlus Auto 13. Fachtagung für neue Fahrzeug- und Werkstoffkonzepte
TI - NeMo.bil - Dekarbonisierung des Verkehrs mithilfe von Leichtbau-Fahrzeugschwärmen
ER -
TY - JOUR
AU - Kaur, Mannat
AU - Ramulu, Harshini Sri
AU - Acar, Yasemin
AU - Fiebig, Tobias
ID - 45984
IS - CSCW1
JF - Proc. ACM Hum. Comput. Interact.
TI - "Oh yes! over-preparing for meetings is my jam :)": The Gendered Experiences of System Administrators
VL - 7
ER -
TY - JOUR
AU - Bouma-Sims, Elijah
AU - Acar, Yasemin
ID - 45983
IS - CSCW1
JF - Proc. ACM Hum. Comput. Interact.
TI - Beyond the Boolean: How Programmers Ask About, Use, and Discuss Gender
VL - 7
ER -
TY - JOUR
AU - Vöing, Nerea
ID - 46622
JF - Lehren im Leben - Blog der Stiftung Innovation in der Hochschullehre
TI - 16 Fragen, 16 Antworten: In unserer Rubrik „Lehren im Leben” stellen wir Menschen vor, die Hochschullehre gestalten. Folge 6: Dr. Nerea Vöing
VL - 6
ER -
TY - GEN
AB - We discuss in which cases the Dunkl convolution of distributions, possibly
both with non-compact support, can be defined and study its analytic
properties. We prove results on the (singular-)support of Dunkl convolutions.
Based on this, we are able to prove a theorem on elliptic regularity for a
certain class of Dunkl operators, called elliptic Dunkl operators. Finally, for
the root systems of type A we consider the Dunkl-type Riesz distributions,
prove that their Dunkl convolution exists and compute their convolution.
AU - Brennecken, Dominik
ID - 46614
T2 - arXiv:2308.07710
TI - Dunkl convolution and elliptic regularity for Dunkl operators
ER -
TY - JOUR
AU - Vöing, Nerea
ID - 46623
JF - Trafohaus//Lehre (Podcast der HD Sachsen)
TI - Ein Blick auf Lehre und Lernen in Hochschulen durch die Brille der Hochschuldidaktik"
ER -
TY - GEN
AU - Vöing, Nerea
AU - Arnold, Maik
AU - Reisas, Sabine
ID - 46624
TI - Lehrentwicklung durch Scholarship of Teaching and Learning – mit SoTL Hochschullehre beforschen, weiterentwickeln und teilen
ER -
TY - JOUR
AU - Karakaya, Yasin
AU - Somnitz, H.
AU - Hermsen, A.
AU - Gonchikzhapov, Munko
AU - Kasper, Tina
ID - 45602
JF - Applications in Energy and Combustion Science
KW - Metastable particles
KW - Nanomaterials
KW - Quartz-crystal-microbalance
KW - Molecular-beam mass spectrometry
KW - Tetramethylsilane
KW - Reaction kinetics
SN - 2666-352X
TI - Revisiting the initial reaction rates for TMS combustion and a new evidence for metastable silica nanoparticles in the gas-phase synthesis
VL - 14
ER -
TY - CONF
AB - New technologies and materials carry significant potential for sustainable production and use of products. As an example, Additive Manufacturing technologies and materials promise lightweight design and energy efficient use of parts. Exhausting the full potential requires: a) consideration of uncertainties with respect to future capabilities, and b) upgradeable design guidelines to cover advancements consistently. The proposed approach merges concepts of Design-for-X with foresight algorithms of Scenario-Technique to derive actionable knowledge. It is validated by an application in the field of Additive Manufacturing, namely Metal Fused Deposition Modelling. Engineers benefit from the intuitive access to heterogeneous types of sustainability related information.
AU - Gräßler, Iris
AU - Mozgova, Iryna
AU - Pottebaum, Jens
AU - Ott, Manuel
AU - Jung, Philipp
AU - Hesse, Philipp
ED - Teti, Roberto
ID - 46451
KW - Design-for-X
KW - Scenario-Technique
KW - sustainability
KW - uncertainty
KW - Life-Cycle Engineering
KW - Additive Manufacturing
KW - Circular Economy
T2 - Procedia CIRP ICME
TI - Handling of uncertainties in the design of sustainable Additive Manufacturing products by merging Design-for-X and Scenario-Technique
ER -
TY - JOUR
AB - A reliable, but cost-effective generation of single-photon states is key for practical quantum communication systems. For real-world deployment, waveguide sources offer optimum compatibility with fiber networks and can be embedded in hybrid integrated modules. Here, we present what we believe to be the first chip-size fully integrated fiber-coupled heralded single photon source (HSPS) module based on a hybrid integration of a nonlinear lithium niobate waveguide into a polymer board. Photon pairs at 810 nm (signal) and 1550 nm (idler) are generated via parametric down-conversion pumped at 532 nm in the LiNbO3 waveguide. The pairs are split in the polymer board and routed to separate output ports. The module has a size of (2 × 1) cm^2 and is fully fiber-coupled with one pump input fiber and two output fibers. We measure a heralded second-order correlation function of g_h(2)=0.05 with a heralding efficiency of η_h=3.5% at low pump powers
AU - Kießler, Christian
AU - Conradi, Hauke
AU - Kleinert, Moritz
AU - Quiring, Viktor
AU - Herrmann, Harald
AU - Silberhorn, Christine
ID - 46644
IS - 14
JF - Optics Express
KW - Atomic and Molecular Physics
KW - and Optics
SN - 1094-4087
TI - Fiber-coupled plug-and-play heralded single photon source based on Ti:LiNbO3 and polymer technology
VL - 31
ER -
TY - CHAP
AB - SoTL ist eine forschungsbasierte Haltung, die die Hochschullehre verbessern und innovieren will. Das deutschsprachige SoTL-Netzwerk hat fünf Thesen formuliert, die SoTL als Grundhaltung und Motor für Lehrentwicklung betonen. Der Beitrag diskutiert diese Thesen und stellt Aktivitäten des Netzwerks vor, die SoTL an Hochschulen und Universitäten fördern und vernetzen wollen. Dabei wird auch die Rolle der »Teacher-Researcher« hervorgehoben.
AU - Arnold, Maik
AU - Vöing, Nerea
AU - Reisas, Sabine
ID - 46647
SN - 2749-7623
T2 - Hochschulbildung: Lehre und Forschung
TI - Scholarship of Teaching and Learning (SoTL) als Motor für eine inter- und transdisziplinäre Hochschuldidaktik
ER -
TY - CONF
AU - Weller, Julian
AU - Roesmann, Daniel
AU - Eggert, Sönke
AU - von Enzberg, Sebastian
AU - Gräßler, Iris
AU - Dumitrescu, Roman
ID - 46493
SN - 2212-8271
T2 - Procedia CIRP
TI - Identification and prediction of standard times in machining for precision steel tubes through the usage of data analytics
VL - 119
ER -
TY - CONF
AU - Althaus, Maike
AU - Grieger, Nicole
AU - Vorbohle, Christian
AU - Müller, Michelle
AU - Kundisch, Dennis
ID - 46646
TI - Business Models for Cultural Event Platforms - A Taxonomy Approach
ER -
TY - GEN
AU - Mapura Ramirez, Luz Alejandra
AU - Kenig, Eugeny Y.
ID - 46591
TI - Zur Berechnug von flüssigkeitsseitigen Stoffübergagnskoeffizienten für Strukturpackungen
ER -
TY - JOUR
AB - The Koopman operator has become an essential tool for data-driven approximation of dynamical (control) systems in recent years, e.g., via extended dynamic mode decomposition. Despite its popularity, convergence results and, in particular, error bounds are still quite scarce. In this paper, we derive probabilistic bounds for the approximation error and the prediction error depending on the number of training data points; for both ordinary and stochastic differential equations. Moreover, we extend our analysis to nonlinear control-affine systems using either ergodic trajectories or i.i.d.
samples. Here, we exploit the linearity of the Koopman generator to obtain a bilinear system and, thus, circumvent the curse of dimensionality since we do not autonomize the system by augmenting the state by the control inputs. To the
best of our knowledge, this is the first finite-data error analysis in the stochastic and/or control setting. Finally, we demonstrate the effectiveness of the proposed approach by comparing it with state-of-the-art techniques showing its superiority whenever state and control are coupled.
AU - Nüske, Feliks
AU - Peitz, Sebastian
AU - Philipp, Friedrich
AU - Schaller, Manuel
AU - Worthmann, Karl
ID - 23428
JF - Journal of Nonlinear Science
TI - Finite-data error bounds for Koopman-based prediction and control
VL - 33
ER -
TY - GEN
AB - Different conflicting optimization criteria arise naturally in various Deep
Learning scenarios. These can address different main tasks (i.e., in the
setting of Multi-Task Learning), but also main and secondary tasks such as loss
minimization versus sparsity. The usual approach is a simple weighting of the
criteria, which formally only works in the convex setting. In this paper, we
present a Multi-Objective Optimization algorithm using a modified Weighted
Chebyshev scalarization for training Deep Neural Networks (DNNs) with respect
to several tasks. By employing this scalarization technique, the algorithm can
identify all optimal solutions of the original problem while reducing its
complexity to a sequence of single-objective problems. The simplified problems
are then solved using an Augmented Lagrangian method, enabling the use of
popular optimization techniques such as Adam and Stochastic Gradient Descent,
while efficaciously handling constraints. Our work aims to address the
(economical and also ecological) sustainability issue of DNN models, with a
particular focus on Deep Multi-Task models, which are typically designed with a
very large number of weights to perform equally well on multiple tasks. Through
experiments conducted on two Machine Learning datasets, we demonstrate the
possibility of adaptively sparsifying the model during training without
significantly impacting its performance, if we are willing to apply
task-specific adaptations to the network weights. Code is available at
https://github.com/salomonhotegni/MDMTN.
AU - Hotegni, Sedjro Salomon
AU - Peitz, Sebastian
AU - Berkemeier, Manuel Bastian
ID - 46649
T2 - arXiv:2308.12243
TI - Multi-Objective Optimization for Sparse Deep Neural Network Training
ER -
TY - JOUR
AU - Gonchikzhapov, Munko
AU - Kasper, Tina
ID - 46637
JF - Applications in Energy and Combustion Science
KW - Nanoparticle synthesis
KW - Flame spray pyrolysis
KW - SpraySyn burner
KW - Flame structure
KW - Species distribution
KW - Temperature distribution
SN - 2666-352X
TI - Thermal and chemical structure of ethanol and 2-ethylhexanoic acid/ethanol SpraySyn flames
VL - 15
ER -
TY - JOUR
AB - Many problems in science and engineering require an efficient numerical approximation of integrals or solutions to differential equations. For systems with rapidly changing dynamics, an equidistant discretization is often inadvisable as it results in prohibitively large errors or computational effort. To this end, adaptive schemes, such as solvers based on Runge–Kutta pairs, have been developed which adapt the step size based on local error estimations at each step. While the classical schemes apply very generally and are highly efficient on regular systems, they can behave suboptimally when an inefficient step rejection mechanism is triggered by structurally complex systems such as chaotic systems. To overcome these issues, we propose a method to tailor numerical schemes to the problem class at hand. This is achieved by combining simple, classical quadrature rules or ODE solvers with data-driven time-stepping controllers. Compared with learning solution operators to ODEs directly, it generalizes better to unseen initial data as our approach employs classical numerical schemes as base methods. At the same time it can make use of identified structures of a problem class and, therefore, outperforms state-of-the-art adaptive schemes. Several examples demonstrate superior efficiency. Source code is available at https://github.com/lueckem/quadrature-ML.
AU - Dellnitz, Michael
AU - Hüllermeier, Eyke
AU - Lücke, Marvin
AU - Ober-Blöbaum, Sina
AU - Offen, Christian
AU - Peitz, Sebastian
AU - Pfannschmidt, Karlson
ID - 21600
IS - 2
JF - SIAM Journal on Scientific Computing
TI - Efficient time stepping for numerical integration using reinforcement learning
VL - 45
ER -
TY - CHAP
AU - Dahms, Frederik
AU - Homberg, Werner
ID - 46691
SN - 2195-4356
T2 - Lecture Notes in Mechanical Engineering
TI - Analysis and Modelling of the Deformation in the Manufacture of Flange-Contours by the Combined Friction-Spinning and Flow-Forming Process
ER -
TY - CONF
AU - Garnefeld, I.
AU - Böhm, Eva
AU - Hanf, L.
AU - Helm, S.
ID - 46665
T2 - 2023 AMA Summer Academic Conference, San Francisco, CA
TI - Unboxing video effectiveness – Does speech matter?
ER -
TY - CONF
AU - Kessing, K.
AU - Garnefeld, I.
AU - Böhm, Eva
ID - 46666
T2 - EMAC Annual Conference, Odense, Denmark
TI - The dark and bright side of online reviews in manufacturer online shops
ER -
TY - CONF
AU - Hanf, L.
AU - Garnefeld, I.
AU - Böhm, Eva
AU - Helm, S.
ID - 46667
T2 - EMAC Annual Conference, Odense, Denmark
TI - Stimulating engagement with unboxing videos – Does speech matter?
ER -
TY - CONF
AU - Sadeghi-Kohan, Somayeh
AU - Hellebrand, Sybille
AU - Wunderlich, Hans-Joachim
ID - 46739
T2 - 2023 53rd Annual IEEE/IFIP International Conference on Dependable Systems and Networks Workshops (DSN-W)
TI - Low Power Streaming of Sensor Data Using Gray Code-Based Approximate Communication
ER -
TY - CONF
AU - Janzen, Thomas
AU - Wotschel, Philipp
AU - Meier, Jana
AU - Vogelsang, Christoph
ID - 46740
T2 - EARLI 2023
TI - Assessing pre-service EFL teachers’ feedback performance in role-play-based simulations
ER -
TY - JOUR
AU - Zscherp, Mario Fabian
AU - Jentsch, Silas Aurel
AU - Müller, Marius Johannes
AU - Lider, Vitalii
AU - Becker, Celina
AU - Chen, Limei
AU - Littmann, Mario
AU - Meier, Falco
AU - Beyer, Andreas
AU - Hofmann, Detlev Michael
AU - As, Donat Josef
AU - Klar, Peter Jens
AU - Volz, Kerstin
AU - Chatterjee, Sangam
AU - Schörmann, Jörg
ID - 46741
IS - 33
JF - ACS Applied Materials & Interfaces
KW - General Materials Science
SN - 1944-8244
TI - Overcoming the Miscibility Gap of GaN/InN in MBE Growth of Cubic InxGa1–xN
VL - 15
ER -
TY - CONF
AU - Müller, Michelle
AU - Neumann, Jürgen
ID - 33722
T2 - Proceedings of the 55th Hawaii International Conference on System Sciences (HICSS)
TI - Bring me my Meal on your Wheel - An Empirical Analysis of the Impact of Food Delivery Platforms on Local Restaurant Employment
ER -
TY - JOUR
AB - AbstractWorking conditions of knowledge workers have been subject to rapid change recently. Digital nomadism is no longer a phenomenon that relates only to entrepreneurs, freelancers, and gig workers. Corporate employees, too, have begun to uncouple their work from stationary (home) offices and 9-to-5 schedules. However, pursuing a permanent job in a corporate environment is still subject to fundamentally different values than postulated by the original notion of digital nomadism. Therefore, this paper explores the work identity of what is referred to as ‘corporate nomads’. By drawing on identity theory and the results of semi-structured interviews, the paper proposes a conceptualization of the corporate nomad archetype and presents nine salient identity issues of corporate nomads (e.g., holding multiple contradictory identities, the flexibility paradox, or collaboration constraints). By introducing the ‘corporate nomad’ archetype to the Information Systems literature, this article helps to rethink established conceptions of “home office” and socio-spatial configurations of knowledge work.
AU - Marx, Julian
AU - Stieglitz, Stefan
AU - Brünker, Felix
AU - Mirbabaie, Milad
ID - 44143
JF - Business & Information Systems Engineering
KW - Information Systems
SN - 2363-7005
TI - Home (Office) is where your Heart is
ER -
TY - JOUR
AU - Zander, K.K.
AU - Nguyen, D.
AU - Mirbabaie, Milad
AU - Garnett, S.T.
ID - 46487
JF - International Journal of Disaster Risk Reduction
KW - Geology
KW - Safety Research
KW - Geotechnical Engineering and Engineering Geology
KW - Building and Construction
SN - 2212-4209
TI - Aware but not prepared: understanding situational awareness during the century flood in Germany in 2021
VL - 96
ER -
TY - BOOK
AB - In the proposal for our CRC in 2011, we formulated a vision of markets for
IT services that describes an approach to the provision of such services
that was novel at that time and, to a large extent, remains so today:
„Our vision of on-the-fly computing is that of IT services individually and
automatically configured and brought to execution from flexibly combinable
services traded on markets. At the same time, we aim at organizing
markets whose participants maintain a lively market of services through
appropriate entrepreneurial actions.“
Over the last 12 years, we have developed methods and techniques to
address problems critical to the convenient, efficient, and secure use of
on-the-fly computing. Among other things, we have made the description
of services more convenient by allowing natural language input,
increased the quality of configured services through (natural language)
interaction and more efficient configuration processes and analysis
procedures, made the quality of (the products of) providers in the
marketplace transparent through reputation systems, and increased the
resource efficiency of execution through reconfigurable heterogeneous
computing nodes and an integrated treatment of service description and
configuration. We have also developed network infrastructures that have
a high degree of adaptivity, scalability, efficiency, and reliability, and
provide cryptographic guarantees of anonymity and security for market
participants and their products and services.
To demonstrate the pervasiveness of the OTF computing approach, we
have implemented a proof-of-concept for OTF computing that can run
typical scenarios of an OTF market. We illustrated the approach using
a cutting-edge application scenario – automated machine learning (AutoML).
Finally, we have been pushing our work for the perpetuation of
On-The-Fly Computing beyond the SFB and sharing the expertise gained
in the SFB in events with industry partners as well as transfer projects.
This work required a broad spectrum of expertise. Computer scientists
and economists with research interests such as computer networks and
distributed algorithms, security and cryptography, software engineering
and verification, configuration and machine learning, computer engineering
and HPC, microeconomics and game theory, business informatics
and management have successfully collaborated here.
AU - Haake, Claus-Jochen
AU - Meyer auf der Heide, Friedhelm
AU - Platzner, Marco
AU - Wachsmuth, Henning
AU - Wehrheim, Heike
ID - 45863
TI - On-The-Fly Computing -- Individualized IT-services in dynamic markets
VL - 412
ER -
TY - JOUR
AU - Stieglitz, Stefan
AU - Mirbabaie, Milad
AU - Deubel, Annika
AU - Braun, Lea-Marie
AU - Kissmer, Tobias
ID - 45458
JF - International Journal of Information Management
KW - Library and Information Sciences
KW - Computer Networks and Communications
KW - Information Systems
SN - 0268-4012
TI - The potential of digital nudging to bridge the gap between environmental attitude and behavior in the usage of smart home applications
VL - 72
ER -
TY - JOUR
AU - Mirbabaie, Milad
AU - Marx, Julian
AU - Erle, Lukas
ID - 46746
JF - Pacific Asia Journal of the Association for Information Systems
SN - 1943-7544
TI - Digital Nudge Stacking and Backfiring: Understanding Sustainable E-Commerce Purchase Decisions
ER -
TY - DATA
AB - Die Energieaufnahme von Haushaltskältegeräten ist seit den 1990er Jahren erheblich gesunken. Dieser Wert wird von den Herstellern im Neuzustand der Geräte unter Normbedingungen bestimmt. Wie jedes technische System unterliegen jedoch auch Haushaltskältegeräte einem Alterungsprozess, der zu einem Anstieg der Energieaufnahme über die Zeit führt. Im Rahmen dieser Dissertation wurde auf der Grundlage von 100 Messungen der Energieaufnahme, die an 32 Geräten über einen Zeitraum von 21 Jahren durchgeführt wurden, ein Alterungsmodell entwickelt. Dieses Modell ist das erste, das mit Hilfe von Daten der Energieaufnahme real gealterter Geräte entwickelt wurde. Es beschreibt einen Anstieg der Energieaufnahme von 27 % über die durchschnittliche Einsatzzeit eines Haushaltskältegeräts von 16 Jahren. Der stärkste Anstieg erfolgt in den ersten fünf Betriebsjahren. Durch Diffusionsvorgänge in dem im Gehäuse verbauten Polyurethan-Schaum wird das im Zellgas vorhandene Kohlenstoffdioxid durch Luft ersetzt. Hierdurch steigt die Wärmeleitfähigkeit des Schaums um ca. 33 % an, wodurch sich die Energieaufnahme der Geräte erhöht. Des Weiteren wurde der Einsatz von Paraffinen als Phasenwechselmaterial in Haushaltskältegeräten untersucht. Durch deren Einsatz konnte die Energieaufnahme gesenkt und die Funktionalität der Geräte gesteigert werden. Hierfür sind detaillierte Kenntnisse der Materialkenndaten der Paraffine notwendig. Die Wärmeleitfähigkeit der verschiedenen Paraffin-Stoffgruppen in der festen Phase ist jedoch bisher nur unzureichend untersucht worden. Daher wurde ein Messaufbau entwickelt, mit dem die Wärmeleitfähigkeit von festem Paraffin bestimmt werden kann, und es wurden entsprechende Messungen durchgeführt.
AU - Paul, Andreas
ID - 46753
TI - Analyse von Alterungsmechanismen im Hinblick auf die Effizienz von Haushaltskältegeräten
ER -
TY - JOUR
AB - Qualitative comparative analysis (QCA) enables researchers in international management to better understand how the impact of a single explanatory factor depends on the context of other factors. But the analytical toolbox of QCA does not include a parameter for the explanatory power of a single explanatory factor or “condition”. In this paper, we therefore reinterpret the Banzhaf power index, originally developed in cooperative game theory, to establish a goodness-of-fit parameter in QCA. The relative Banzhaf index we suggest measures the explanatory power of one condition averaged across all sufficient combinations of conditions. The paper argues that the index is especially informative in three situations that are all salient in international management and call for a context-sensitive analysis of single conditions, namely substantial limited diversity in the data, the emergence of strong INUS conditions in the analysis, and theorizing with contingency factors. The paper derives the properties of the relative Banzhaf index in QCA, demonstrates how the index can be computed easily from a rudimentary truth table, and explores its insights by revisiting selected papers in international management that apply fuzzy-set QCA. It finally suggests a three-step procedure for utilizing the relative Banzhaf index when the causal structure involves both contingency effects and configurational causation.
AU - Haake, Claus-Jochen
AU - Schneider, Martin
ID - 34114
JF - Journal of International Management
KW - Qualitative comparative analysis
KW - Banzhaf power index
KW - causality
KW - explanatory power
TI - Playing games with QCA: Measuring the explanatory power of single conditions with the Banzhaf index
ER -