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 -