TY - JOUR
AB - This study examines the gender gap in competitiveness in an educational setting
and tests whether this gap depends on the difficulty of the task at hand. For this purpose,
we administered a series of experiments during the final exam of a university
course. We confronted three cohorts of undergraduate students with a set of bonus
questions and the choice between an absolute and a tournament grading scheme
for these questions. To test the moderating impact of task difficulty, we (randomly)
varied the difficulty of the questions between treatment groups. We find that, on
average, women are significantly less likely to select the tournament scheme. However,
the results show that the gender gap in tournament entry is sizable when the
questions are relative easy, but much smaller and statistical insignificant when the
questions are difficult.
AU - Hoyer, Britta
AU - van Huizen, Thomas
AU - Keijzer, Linda
AU - Rezaei, Sarah
AU - Rosenkranz, Stephanie
AU - Westbrock, Bastian
ID - 16273
JF - Labour Economics
TI - Gender, competitiveness, and task difficulty: Evidence from the field
ER -
TY - JOUR
AB - Currently, the coexistence of multiple users and devices challenges the network's ability to reliably connect them. This article proposes a novel communication architecture that satisfies the requirements of fifth-generation (5G) mobile network applications. In particular, this architecture extends and combines ultra-dense networking (UDN), multi-access edge computing (MEC), and virtual infrastructure manager (VIM) concepts to provide a flexible network of moving radio access (RA) nodes, flying or moving to areas where users and devices struggle for connectivity and data rate. Furthermore, advances in radio communications and non-orthogonal multiple access (NOMA), virtualization technologies and energy-awareness mechanisms are integrated towards a mobile UDN that not only allows RA nodes to follow the user but also enables the virtualized network functions (VNFs) to adapt to user mobility by migrating from one node to another. Performance evaluation shows that the underlying network improves connectivity of users and devices through the flexible deployment of moving RA nodes and the use of NOMA.
AU - Nomikos, Nikolaos
AU - Michailidis, Emmanouel T.
AU - Trakadas, Panagiotis
AU - Vouyioukas, Demosthenes
AU - Karl, Holger
AU - Martrat, Josep
AU - Zahariadis, Theodore
AU - Papadopoulos, Konstantinos
AU - Voliotis, Stamatis
ID - 16278
JF - Vehicular Communications
SN - 2214-2096
TI - A UAV-based moving 5G RAN for massive connectivity of mobile users and IoT devices
ER -
TY - JOUR
AB - Assigning bands of the wireless spectrum as resources to users is a common problem in wireless networks. Typically, frequency bands were assumed to be available in a stable manner. Nevertheless, in recent scenarios where wireless networks may be deployed in unknown environments, spectrum competition is considered, making it uncertain whether a frequency band is available at all or at what quality. To fully exploit such resources with uncertain availability, the multi-armed bandit (MAB) method, a representative online learning technique, has been applied to design spectrum scheduling algorithms. This article surveys such proposals. We describe the following three aspects: how to model spectrum scheduling problems within the MAB framework, what the main thread is following which prevalent algorithms are designed, and how to evaluate algorithm performance and complexity. We also give some promising directions for future research in related fields.
AU - Li, Feng
AU - Yu, Dongxiao
AU - Yang, Huan
AU - Yu, Jiguo
AU - Karl, Holger
AU - Cheng, Xiuzhen
ID - 16280
JF - IEEE Wireless Communications
SN - 1536-1284
TI - Multi-Armed-Bandit-Based Spectrum Scheduling Algorithms in Wireless Networks: A Survey
ER -
TY - CONF
AB - To decide in which part of town to open stores, high street retailers consult statistical data on customers and cities, but they cannot analyze their customers’ shopping behavior and geospatial features of a city due to missing data. While previous research has proposed recommendation systems and decision aids that address this type of decision problem – including factory location and assortment planning – there currently is no design knowledge available to prescribe the design of city center area recommendation systems (CCARS). We set out to design a software prototype considering local customers’ shopping interests and geospatial data on their shopping trips for retail site selection. With real data on 500 customers and 1,100 shopping trips, we demonstrate and evaluate our IT artifact. Our results illustrate how retailers and public town center managers can use CCARS for spatial location selection, growing retailers’ profits and a city center’s attractiveness for its citizens.
AU - zur Heiden, Philipp
AU - Berendes, Carsten Ingo
AU - Beverungen, Daniel
ID - 16285
KW - Town Center Management
KW - High Street Retail
KW - Recommender Systems
KW - Geospatial Recommendations
KW - Design Science Research
T2 - Proceedings of the 15th International Conference on Wirtschaftsinformatik
TI - Designing City Center Area Recommendation Systems
ER -
TY - GEN
AB - In real-world problems, uncertainties (e.g., errors in the measurement,
precision errors) often lead to poor performance of numerical algorithms when
not explicitly taken into account. This is also the case for control problems,
where optimal solutions can degrade in quality or even become infeasible. Thus,
there is the need to design methods that can handle uncertainty. In this work,
we consider nonlinear multi-objective optimal control problems with uncertainty
on the initial conditions, and in particular their incorporation into a
feedback loop via model predictive control (MPC). In multi-objective optimal
control, an optimal compromise between multiple conflicting criteria has to be
found. For such problems, not much has been reported in terms of uncertainties.
To address this problem class, we design an offline/online framework to compute
an approximation of efficient control strategies. This approach is closely
related to explicit MPC for nonlinear systems, where the potentially expensive
optimization problem is solved in an offline phase in order to enable fast
solutions in the online phase. In order to reduce the numerical cost of the
offline phase, we exploit symmetries in the control problems. Furthermore, in
order to ensure optimality of the solutions, we include an additional online
optimization step, which is considerably cheaper than the original
multi-objective optimization problem. We test our framework on a car
maneuvering problem where safety and speed are the objectives. The
multi-objective framework allows for online adaptations of the desired
objective. Alternatively, an automatic scalarizing procedure yields very
efficient feedback controls. Our results show that the method is capable of
designing driving strategies that deal better with uncertainties in the initial
conditions, which translates into potentially safer and faster driving
strategies.
AU - Hernández Castellanos, Carlos Ignacio
AU - Ober-Blöbaum, Sina
AU - Peitz, Sebastian
ID - 16297
T2 - arXiv:2002.06006
TI - Explicit Multi-objective Model Predictive Control for Nonlinear Systems Under Uncertainty
ER -
TY - CONF
AU - Wolf, Verena
AU - Bartelheimer, Christian
ID - 16300
T2 - 16th International Research Conference in Service Management
TI - Transformation of Actors’ Roles in Service Systems: A Multi-Level Analysis (Accepted)
ER -
TY - GEN
AU - Kittsteiner, Anna Verena
ID - 16343
TI - Eine strategische Analyse von Online-Kundenrezensionen zur Identifikation von Begeisterungsfaktoren mittels Latent Dirichlet Allocation
ER -
TY - JOUR
AU - Goller, Michael
AU - Harteis, Christian
AU - Gijbels, David
AU - Donche, Vincent
ID - 16507
IS - 2
JF - Journal of Engineering Education
SN - 1069-4730
TI - Engineering students' learning during internships: Exploring the explanatory power of the job demands‐control‐support model
VL - 109
ER -
TY - GEN
AU - Gutperl, Sven
AU - Bolenz, Lukas
AU - Kriese, Friederike
AU - Jasch, Katharina
AU - Kenig, Eugeny
AU - Scholl, Stephan
ID - 16204
TI - Simulation und Bewertung eines Anlagenkonzepts für Trennleistungsmessungen mit nicht-verdampfenden Komponenten
ER -
TY - GEN
AU - Rosenhäger, Tjard Henrik
ID - 16571
TI - Nothing comes for free - Ein klassifizierender Überblick zu den Auswirkungen finanzieller Anreize auf digitalen Märkten
ER -
TY - JOUR
AU - Krimphove, Dieter
ID - 16095
IS - 1
JF - Rechtstheorie
SN - 0034-1398
TI - Die „Logik“ der Überzeugungskraft
VL - 50
ER -
TY - JOUR
AU - Javed, Muhammad Ali
AU - Rüther, Moritz
AU - Baumhögger, Elmar
AU - Vrabec, Jadran
ID - 16848
JF - Journal of Chemical & Engineering Data
SN - 0021-9568
TI - Density and Thermodynamic Speed of Sound of Liquid Vinyl Chloride
ER -
TY - CONF
AU - Krauter, Stefan
AU - Zhang, L.
ID - 16855
T2 - Tagungsband des 35. Symposiums für Photovoltaische Solarenergie, Kloster Banz, Bad Staffelstein (Deutschland)
TI - Eignung der Netzfrequenz als Instrument der Entscheidungsfindung zur Auslösung von Lastverschiebungen bei niedrigen spezifischen CO 2 -Emsissionen und EEX- Handelspreisen
ER -
TY - JOUR
AU - Bohn, Nicolai
AU - Kundisch, Dennis
ID - 16862
JF - Information & Management
TI - What Are We Talking About When We Talk About Technology Pivots? – A Delphi Study
ER -
TY - GEN
AB - In this article, we present an efficient descent method for locally Lipschitz
continuous multiobjective optimization problems (MOPs). The method is realized
by combining a theoretical result regarding the computation of descent
directions for nonsmooth MOPs with a practical method to approximate the
subdifferentials of the objective functions. We show convergence to points
which satisfy a necessary condition for Pareto optimality. Using a set of test
problems, we compare our method to the multiobjective proximal bundle method by
M\"akel\"a. The results indicate that our method is competitive while being
easier to implement. While the number of objective function evaluations is
larger, the overall number of subgradient evaluations is lower. Finally, we
show that our method can be combined with a subdivision algorithm to compute
entire Pareto sets of nonsmooth MOPs.
AU - Gebken, Bennet
AU - Peitz, Sebastian
ID - 16867
T2 - arXiv:2004.11578
TI - An efficient descent method for locally Lipschitz multiobjective optimization problems
ER -
TY - JOUR
AU - Gilroy, Bernard Michael
AU - Peitz, Christian
ID - 16879
IS - 1
JF - WISU – Das Wirtschaftsstudium
TI - Die Niedrigzinspolitik der Europäischen Zentralbank
ER -
TY - GEN
AB - Electronic structure calculations based on density-functional theory (DFT)
represent a significant part of today's HPC workloads and pose high demands on
high-performance computing resources. To perform these quantum-mechanical DFT
calculations on complex large-scale systems, so-called linear scaling methods
instead of conventional cubic scaling methods are required. In this work, we
take up the idea of the submatrix method and apply it to the DFT computations
in the software package CP2K. For that purpose, we transform the underlying
numeric operations on distributed, large, sparse matrices into computations on
local, much smaller and nearly dense matrices. This allows us to exploit the
full floating-point performance of modern CPUs and to make use of dedicated
accelerator hardware, where performance has been limited by memory bandwidth
before. We demonstrate both functionality and performance of our implementation
and show how it can be accelerated with GPUs and FPGAs.
AU - Lass, Michael
AU - Schade, Robert
AU - Kühne, Thomas
AU - Plessl, Christian
ID - 16898
TI - A Submatrix-Based Method for Approximate Matrix Function Evaluation in the Quantum Chemistry Code CP2K
ER -
TY - GEN
AB - Let $\phi_c(G)$ be the circular flow number of a bridgeless graph $G$. In [Edge-colorings and circular flow numbers of regular graphs, J. Graph Theory 79 (2015) 1-7] it was proved that, for every $t \geq 1$, $G$ is a bridgeless $(2t+1)$-regular graph with $\phi_c(G) \in \{2+\frac{1}{t}, 2 + \frac{2}{2t-1}\}$ if and only if $G$ has a perfect matching $M$ such that $G-M$ is bipartite. This implies that $G$ is a class 1 graph. For $t=1$, all graphs with circular flow number bigger than 4 are class 2 graphs. We show for all $t \geq 1$, that $2 + \frac{2}{2t-1} = \inf \{ \phi_c(G)\colon G \text{ is a } (2t+1) \text{-regular class } 2 \text{ graph}\}$. This was conjectured to be true in [Edge-colorings and circular flow numbers of regular graphs, J. Graph Theory 79 (2015) 1-7]. Moreover we prove that $\inf\{ \phi_c(G)\colon G $ is a $ (2t+1)$-regular class $1$ graph with no perfect matching whose removal leaves a bipartite graph$ \} = 2 + \frac{2}{2t-1}$. We further disprove the conjecture that every $(2t+1)$-regular class $1$ graph has circular flow number at most $2+\frac{2}{t}$.
AU - Mattiolo, Davide
AU - Steffen, Eckhard
ID - 16747
T2 - arXiv:2001.02484
TI - Edge colorings and circular flows on regular graphs
ER -
TY - CONF
AU - Bartelheimer, Christian
AU - Wolf, Verena
AU - Langhorst, Nico
AU - Seegers, Florian
ID - 16800
T2 - Proceedings of the 15th International Conference on Design Science Research in Information Systems and Technology
TI - Designing Digital Community Service Platforms for Crowd-Based Services in Urban Areas
ER -
TY - CONF
AU - El Baff, Roxanne
AU - Wachsmuth, Henning
AU - Al-Khatib, Khalid
AU - Stein, Benno
ED - Tsujii, Junichi
ED - Hajic, Jan
ID - 3878
T2 - Proceedings of 58th Annual Meeting of the Association for Computational Linguistics
TI - Analyzing the Persuasive Effect of Style in News Editorial Argumentation
ER -