TY - JOUR
AU - Kunnathully, Vinay S.
AU - Riedl, Thomas
AU - Trapp, Alexander
AU - Langer, Timo
AU - Reuter, Dirk
AU - Lindner, Jörg K.N.
ID - 17434
JF - Journal of Crystal Growth
SN - 0022-0248
TI - InAs heteroepitaxy on nanopillar-patterned GaAs (111)A
ER -
TY - JOUR
AU - Geier, M.
AU - Freudenfeld, J.
AU - Silva, J. T.
AU - Umansky, V.
AU - Reuter, Dirk
AU - Wieck, A. D.
AU - Brouwer, P. W.
AU - Ludwig, S.
ID - 17435
JF - Physical Review B
SN - 2469-9950
TI - Electrostatic potential shape of gate-defined quantum point contacts
ER -
TY - JOUR
AB - The study of electron transport in low-dimensional systems is of importance, not only from a fundamental point of view, but also for future electronic and spintronic devices. In this context heterostructures containing a two-dimensional electron gas (2DEG) are a key technology. In particular GaAs/AlGaAs heterostructures, with a 2DEG at typically 100 nm below the surface, are widely studied. In order to explore electron transport in such systems, low-resistance ohmic contacts are required that connect the 2DEG to macroscopic measurement leads at the surface. Here we report on designing and measuring a dedicated device for unraveling the various resistance contributions in such contacts, which include pristine 2DEG series resistance, the 2DEG resistance under a contact, the contact resistance itself, and the influence of pressing a bonding wire onto a contact. We also report here a recipe for contacts with very low resistance values that remain below 10 Ω for annealing times between 20 and 350 s, hence providing the flexibility to use this method for materials with different 2DEG depths. The type of heating, temperature ramp rate and gas forming used for annealing is found to strongly influence the annealing process and hence the quality of the resulting contacts.
AU - Javaid Iqbal, Muhammad
AU - Reuter, Dirk
AU - Wieck, Andreas Dirk
AU - van der Wal, Caspar
ID - 17436
JF - The European Physical Journal Applied Physics
SN - 1286-0042
TI - Characterization of low-resistance ohmic contacts to a two-dimensional electron gas in a GaAs/AlGaAs heterostructure
ER -
TY - JOUR
AU - Ebler, C.
AU - Labud, P. A.
AU - Rai, A. K.
AU - Reuter, Dirk
AU - Wieck, A. D.
AU - Ludwig, A.
ID - 17437
JF - Physical Review B
SN - 2469-9950
TI - Electrical detection of excitonic states by time-resolved conductance measurements
ER -
TY - JOUR
AB - Compact and robust cold atom sources are increasingly important for quantum research, especially for transferring cutting-edge quantum science into practical applications. In this study, we report on a novel scheme that uses a metasurface optical chip to replace the conventional bulky optical elements used to produce a cold atomic ensemble with a single incident laser beam, which is split by the metasurface into multiple beams of the desired polarization states. Atom numbers ~107 and temperatures (about 35 μK) of relevance to quantum sensing are achieved in a compact and robust fashion. Our work highlights the substantial progress toward fully integrated cold atom quantum devices by exploiting metasurface optical chips, which may have great potential in quantum sensing, quantum computing, and other areas.
AU - Zhu, Lingxiao
AU - Liu, Xuan
AU - Sain, Basudeb
AU - Wang, Mengyao
AU - Schlickriede, Christian
AU - Tang, Yutao
AU - Deng, Junhong
AU - Li, Kingfai
AU - Yang, Jun
AU - Holynski, Michael
AU - Zhang, Shuang
AU - Zentgraf, Thomas
AU - Bongs, Kai
AU - Lien, Yu-Hung
AU - Li, Guixin
ID - 17523
IS - 31
JF - Science Advances
SN - 2375-2548
TI - A dielectric metasurface optical chip for the generation of cold atoms
VL - 6
ER -
TY - JOUR
AU - Schweizer, Swetlana
AU - Becker-Staines, Anna
AU - Tröster, Thomas
ID - 17578
JF - Waste Management
SN - 0956-053X
TI - Separation and reclamation of automotive hybrid structures made of metal and fibre-reinforced plastic
ER -
TY - JOUR
AU - Sonnenrein, G.
AU - Baumhögger, Elmar
AU - Elsner, A.
AU - Morbach, A.
AU - Neukötter, M.
AU - Paul, A.
AU - Vrabec, J.
ID - 17589
JF - International Journal of Refrigeration
SN - 0140-7007
TI - Improving the performance of household refrigerating appliances through the integration of phase change materials in the context of the new global refrigerator standard IEC 62552:2015
ER -
TY - GEN
AB - Syntactic annotation of corpora in the form of part-of-speech (POS) tags is a key requirement for both linguistic research and subsequent automated natural language processing (NLP) tasks. This problem is commonly tackled using machine learning methods, i.e., by training a POS tagger on a sufficiently large corpus of labeled data.
While the problem of POS tagging can essentially be considered as solved for modern languages, historical corpora turn out to be much more difficult, especially due to the lack of native speakers and sparsity of training data. Moreover, most texts have no sentences as we know them today, nor a common orthography.
These irregularities render the task of automated POS tagging more difficult and error-prone. Under these circumstances, instead of forcing the POS tagger to predict and commit to a single tag, it should be enabled to express its uncertainty. In this paper, we consider POS tagging within the framework of set-valued prediction, which allows the POS tagger to express its uncertainty via predicting a set of candidate POS tags instead of guessing a single one. The goal is to guarantee a high confidence that the correct POS tag is included while keeping the number of candidates small.
In our experimental study, we find that extending state-of-the-art POS taggers to set-valued prediction yields more precise and robust taggings, especially for unknown words, i.e., words not occurring in the training data.
AU - Heid, Stefan Helmut
AU - Wever, Marcel Dominik
AU - Hüllermeier, Eyke
ID - 17605
T2 - Journal of Data Mining and Digital Humanities
TI - Reliable Part-of-Speech Tagging of Historical Corpora through Set-Valued Prediction
ER -
TY - GEN
AB - Employing a unique sample of 2,849 tariff imposition announcements by and against the United States (U.S.) over the period from 2018 to 2019, this study analyzes the impact of recent tariff announcements on share prices from 859 U.S. companies. We provide evidence for negative (cumulative) average abnormal stock returns due to tariff announcements during a symmetric three-day event window. We suggest that stock market investors expect adverse impacts of tariff impositions, e.g. a decrease in the companies' future cash flows and a threat of retaliation. The negative wealth effects are observed irrespective of whether the Trump administration announces safeguard tariffs to protect domestic firms or a retaliation is declared by foreign countries. Moreover, building several subsamples, we find that the adverse impact is mostly driven by announcements involving China and is associated with a variety of sector, tariff, trade and firm characteristics.
AU - Wengerek, Sascha Tobias
ID - 17703
KW - event study
KW - international relations
KW - protectionism
KW - strategic trade policy
KW - tariffs
KW - trade conflict
TI - Share price reactions to tariff imposition announcements in the Trump era - An event study of the trade conflict
ER -
TY - JOUR
AU - Ortmann, Regina
AU - Pelster, Matthias
AU - Wengerek, Sascha Tobias
ID - 17730
JF - Finance Research Letters
SN - 1544-6123
TI - COVID-19 and investor behavior
VL - 37
ER -
TY - CONF
AU - Haeb-Umbach, Reinhold
ED - Böck, Ronald
ED - Siegert, Ingo
ED - Wendemuth, Andreas
ID - 17763
KW - Poster
SN - 978-3-959081-93-1
T2 - Studientexte zur Sprachkommunikation: Elektronische Sprachsignalverarbeitung 2020
TI - Sprachtechnologien für Digitale Assistenten
ER -
TY - JOUR
AB - We numerically simulate multiple light scattering in discrete disordered media represented by large clusters of irregular non-absorbing particles. The packing density of clusters is 0.5. With such conditions diffuse scattering is significantly reduced and light transport follows propagation channels that are determined by the particle size and topology of the medium. This kind of localization produces coherent backscattering intensity surge and enhanced negative polarization branch if compared to lower density samples.
AU - Grynko, Yevgen
AU - Shkuratov, Yuriy
AU - Förstner, Jens
ID - 17803
JF - Journal of Quantitative Spectroscopy and Radiative Transfer
KW - tet_topic_scattering
SN - 0022-4073
TI - Light backscattering from large clusters of densely packed irregular particles
VL - 255
ER -
TY - JOUR
AU - Gmyr, Robert
AU - Hinnenthal, Kristian
AU - Kostitsyna, Irina
AU - Kuhn, Fabian
AU - Rudolph, Dorian
AU - Scheideler, Christian
AU - Strothmann, Thim
ID - 17808
IS - 2
JF - Nat. Comput.
TI - Forming tile shapes with simple robots
VL - 19
ER -
TY - JOUR
AU - Hielscher, Christian
AU - Grenz, Julian
AU - Camberg, Alan Adam
AU - Wingenbach, Nils
ID - 17812
JF - ATZ - Automobiltechnische Zeitschrift
SN - 0001-2785
TI - Ansatz zur effizienteren Auslegung von Hybridbauteilen
ER -
TY - JOUR
AU - Hielscher, Christian
AU - Grenz, Julian
AU - Camberg, Alan Adam
AU - Wingenbach, Nils
ID - 17813
JF - ATZ worldwide
SN - 2192-9076
TI - Approach to More Efficient Design of Hybrid Components
ER -
TY - GEN
AB - Software verification has recently made enormous progress due to the
development of novel verification methods and the speed-up of supporting
technologies like SMT solving. To keep software verification tools up to date
with these advances, tool developers keep on integrating newly designed methods
into their tools, almost exclusively by re-implementing the method within their
own framework. While this allows for a conceptual re-use of methods, it
requires novel implementations for every new technique.
In this paper, we employ cooperative verification in order to avoid
reimplementation and enable usage of novel tools as black-box components in
verification. Specifically, cooperation is employed for the core ingredient of
software verification which is invariant generation. Finding an adequate loop
invariant is key to the success of a verification run. Our framework named
CoVerCIG allows a master verification tool to delegate the task of invariant
generation to one or several specialized helper invariant generators. Their
results are then utilized within the verification run of the master verifier,
allowing in particular for crosschecking the validity of the invariant. We
experimentally evaluate our framework on an instance with two masters and three
different invariant generators using a number of benchmarks from SV-COMP 2020.
The experiments show that the use of CoVerCIG can increase the number of
correctly verified tasks without increasing the used resources
AU - Haltermann, Jan Frederik
AU - Wehrheim, Heike
ID - 17825
T2 - arXiv:2008.04551
TI - Cooperative Verification via Collective Invariant Generation
ER -
TY - GEN
ED - Werneck Richa, Andrea
ED - Scheideler, Christian
ID - 17836
SN - 978-3-030-54920-6
TI - Structural Information and Communication Complexity - 27th International Colloquium, SIROCCO 2020, Paderborn, Germany, June 29 - July 1, 2020, Proceedings
VL - 12156
ER -
TY - GEN
ED - Scheideler, Christian
ED - Spear, Michael
ID - 17839
SN - 978-1-4503-6935-0
TI - SPAA '20: 32nd ACM Symposium on Parallelism in Algorithms and Architectures, Virtual Event, USA, July 15-17, 2020
ER -
TY - CONF
AU - Kersting, Joschka
AU - Bäumer, Frederik Simon
ID - 18686
KW - Software Requirements
KW - Natural Language Processing
KW - Transfer Learning
KW - On-The-Fly Computing
T2 - PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON APPLIED COMPUTING 2020
TI - SEMANTIC TAGGING OF REQUIREMENT DESCRIPTIONS: A TRANSFORMER-BASED APPROACH
ER -
TY - CHAP
AU - Seng, Eva- Maria
AU - Göttmann, Frank
ID - 18776
T2 - Innovation in der Bauwirtschaft – Innovation in the building industry. Wesersandstein vom 16. bis 19. Jahrhundert – Weser Sandstone form the 16th to the 19th Century
TI - Einleitung – Introduction
ER -