TY - CONF
AB - Modern services consist of modular, interconnected
components, e.g., microservices forming a service mesh. To
dynamically adjust to ever-changing service demands, service
components have to be instantiated on nodes across the network.
Incoming flows requesting a service then need to be routed
through the deployed instances while considering node and link
capacities. Ultimately, the goal is to maximize the successfully
served flows and Quality of Service (QoS) through online service
coordination. Current approaches for service coordination are
usually centralized, assuming up-to-date global knowledge and
making global decisions for all nodes in the network. Such global
knowledge and centralized decisions are not realistic in practical
large-scale networks.
To solve this problem, we propose two algorithms for fully
distributed service coordination. The proposed algorithms can be
executed individually at each node in parallel and require only
very limited global knowledge. We compare and evaluate both
algorithms with a state-of-the-art centralized approach in extensive
simulations on a large-scale, real-world network topology.
Our results indicate that the two algorithms can compete with
centralized approaches in terms of solution quality but require
less global knowledge and are magnitudes faster (more than
100x).
AU - Schneider, Stefan Balthasar
AU - Klenner, Lars Dietrich
AU - Karl, Holger
ID - 19607
KW - distributed management
KW - service coordination
KW - network coordination
KW - nfv
KW - softwarization
KW - orchestration
T2 - IEEE International Conference on Network and Service Management (CNSM)
TI - Every Node for Itself: Fully Distributed Service Coordination
ER -
TY - GEN
AU - Bornemann, Tobias
AU - Schipp, Adrian
AU - Sureth-Sloane, Caren
ID - 17505
TI - 2018/2019 Umfrage zur Steuerkomplexität in deutschen Finanzverwaltungen
ER -
TY - JOUR
AU - Szopinski, Daniel
AU - Schoormann, T.
AU - John, Thomas
AU - Knackstedt, R.
AU - Kundisch, Dennis
ID - 6202
IS - 3
JF - Electronic Markets
TI - Software tools for business model innovation: Current state and future challenges
VL - 30
ER -
TY - JOUR
AB - Polarons in dielectric crystals play a crucial role for applications in integrated electronics and optoelectronics. In this work, we use density-functional theory and Green's function methods to explore the microscopic structure and spectroscopic signatures of electron polarons in lithium niobate (LiNbO3). Total-energy calculations and the comparison of calculated electron paramagnetic resonance data with available measurements reveal the formation of bound
polarons at Nb_Li antisite defects with a quasi-Jahn-Teller distorted, tilted configuration. The defect-formation energies further indicate that (bi)polarons may form not only at
Nb_Li antisites but also at structures where the antisite Nb atom moves into a neighboring empty oxygen octahedron. Based on these structure models, and on the calculated charge-transition levels and potential-energy barriers, we propose two mechanisms for the optical and thermal splitting of bipolarons, which provide a natural explanation for the reported two-path recombination of bipolarons. Optical-response calculations based on the Bethe-Salpeter equation, in combination with available experimental data and new measurements of the optical absorption spectrum, further corroborate the geometries proposed here for free and defect-bound (bi)polarons.
AU - Schmidt, Falko
AU - Kozub, Agnieszka
AU - Biktagirov, Timur
AU - Eigner, Christof
AU - Silberhorn, Christine
AU - Schindlmayr, Arno
AU - Schmidt, Wolf Gero
AU - Gerstmann, Uwe
ID - 19190
IS - 4
JF - Physical Review Research
TI - Free and defect-bound (bi)polarons in LiNbO3: Atomic structure and spectroscopic signatures from ab initio calculations
VL - 2
ER -
TY - GEN
AB - This summary focuses on the results of the second Global MNC Tax Complexity Survey. It seeks to provide an overview of tax complexity as faced by multinational corporations (in 2018 and the changes in tax complexity from 2016 to 2018 in OECD countries, taking into account the results of the 2016 Global MNC Tax Complexity Survey).
AU - Hoppe, Thomas
AU - Schanz, Deborah
AU - Schipp, Adrian
AU - Siegel, Felix
AU - Sturm, Susann
AU - Sureth-Sloane, Caren
ID - 17512
TI - 2018 Global MNC Tax Complexity Survey
ER -
TY - JOUR
AU - Ditter, Jan
AU - Aubel, Tobias
AU - Meschut, Gerson
ID - 19753
IS - 1
JF - adhesion ADHESIVES + SEALANTS
TI - Simple Determination of Fast Curing Parameters for Bonded Structures
ER -
TY - GEN
AB - Due to the trend towards lightweight design in car body development mechanical joining technologies become increasingly important. These techniques allow for the joining of dissimilar materials and thus enable multi-material design, while thermic joining methods reach their limits. Semi-tubular self-piercing riveting is an important mechanical joining technology. The rivet production, however, is costly and time-consuming, as the process consists of several process steps including the heat treatment and coating of the rivets in order to achieve an adequate strength and corrosion resistance. The use of high nitrogen steel as rivet material leads to the possibility of reducing process steps and hence increasing the efficiency of the process. However, the high tool loads being expected due to the high strain hardening of the material are a major challenge during the rivet production. Thus, there is a need for appropriate forming strategies, such as the manufacturing of the rivets at elevated temperatures. Prior investigations led to the conclusion that forming already at 200 °C results in a distinct reduction of the yield strength. To create a deeper understanding of the forming behaviour of high nitrogen steel at elevated temperatures, compression tests were conducted in a temperature range between room temperature and 200 °C. The determined true stress – true strain curves are the basis for the further process and tool design of the rivet production. Another key factor for the rivet manufacturing at elevated temperatures is the influence of the process temperature on the tribological conditions. For this reason, ring compression tests at room temperature and 200 °C are carried out. The friction factors are determined on the basis of calibration curves resulting from the numerical analysis of the ring compression process. The investigations indicate that the friction factor at 200 °C is significantly higher compared to room temperature. This essential fact has to be taken into account for the process and tool design for the rivet production using high nitrogen steel.
ED - Kuball, Clara-Maria
ED - Jung, R
ED - Uhe, Benedikt
ED - Meschut, Gerson
ED - Merklein, Marion
ID - 19974
KW - High nitrogen steel
KW - Self-piercing riveting
KW - Joining by forming
KW - Bulk forming
KW - Strain hardening
TI - Influence of the process temperature on the forming behaviour and the friction during bulk forming of high nitrogen steel
VL - 1
ER -
TY - GEN
AU - Warner, Daniel
ID - 15770
TI - On the complexity of local transformations in SDN overlays
ER -
TY - CONF
AB - Let G = (V,E) be an undirected graph on n vertices with non-negative capacities on its edges. The mincut sensitivity problem for the insertion of an edge is defined as follows. Build a compact data structure for G and a given set S ⊆ V of vertices that, on receiving any edge (x,y) ∈ S×S of positive capacity as query input, can efficiently report the set of all pairs from S× S whose mincut value increases upon insertion of the edge (x,y) to G. The only result that exists for this problem is for a single pair of vertices (Picard and Queyranne, Mathematical Programming Study, 13 (1980), 8-16). We present the following results for the single source and the all-pairs versions of this problem.
1) Single source: Given any designated source vertex s, there exists a data structure of size 𝒪(|S|) that can output all those vertices from S whose mincut value to s increases upon insertion of any given edge. The time taken by the data structure to answer any query is 𝒪(|S|).
2) All-pairs: There exists an 𝒪(|S|²) size data structure that can output all those pairs of vertices from S× S whose mincut value gets increased upon insertion of any given edge. The time taken by the data structure to answer any query is 𝒪(k), where k is the number of pairs of vertices whose mincut increases.
For both these versions, we also address the problem of reporting the values of the mincuts upon insertion of any given edge. To derive our results, we use interesting insights into the nearest and the farthest mincuts for a pair of vertices. In addition, a crucial result, that we establish and use in our data structures, is that there exists a directed acyclic graph of 𝒪(n) size that compactly stores the farthest mincuts from all vertices of V to a designated vertex s in the graph. We believe that this result is of independent interest, especially, because it also complements a previously existing result by Hariharan et al. (STOC 2007) that the nearest mincuts from all vertices of V to s is a laminar family, and hence, can be stored compactly in a tree of 𝒪(n) size.
AU - Baswana, Surender
AU - Gupta, Shiv
AU - Knollmann, Till
ED - Grandoni, Fabrizio
ED - Herman, Grzegorz
ED - Sanders, Peter
ID - 20159
KW - Mincut
KW - Sensitivity
KW - Data Structure
SN - 1868-8969
T2 - 28th Annual European Symposium on Algorithms (ESA 2020)
TI - Mincut Sensitivity Data Structures for the Insertion of an Edge
VL - 173
ER -
TY - CONF
AU - Augstein, Mirjam
AU - Buschek, Daniel
AU - Herder, Eelco
AU - Loepp, Benedikt
AU - Yigitbas, Enes
AU - Ziegler, Jürgen
ID - 18022
T2 - Proceedings of the Mensch und Computer 2020 (MuC ’20)
TI - UCAI 2020 - 1st International Workshop on User-Centered Artificial Intelligence
ER -
TY - JOUR
AU - Gries, T.
AU - Redlin, M.
ID - 17086
JF - International Economics and Economic Policy
SN - 1612-4804
TI - Trade and economic development: global causality and development- and openness-related heterogeneity
VL - 17
ER -
TY - CONF
AB - In this work, we initiate the research about the Gathering problem for robots
with limited viewing range in the three-dimensional Euclidean space. In the
Gathering problem, a set of initially scattered robots is required to gather at
the same position. The robots' capabilities are very restricted -- they do not
agree on any coordinate system or compass, have a limited viewing range, have
no memory of the past and cannot communicate. We study the problem in two
different time models, in FSYNC (fully synchronized discrete rounds) and the
continuous time model. For FSYNC, we introduce the 3D-Go-To-The-Center-strategy
and prove a runtime of $\Theta(n^2)$ that matches the currently best runtime
bound for the same model in the Euclidean plane [SPAA'11]. Our main result is
the generalization of contracting strategies (continuous time) from
[Algosensors'17] to three dimensions. In contracting strategies, every robot
that is located on the global convex hull of all robots' positions moves with
full speed towards the inside of the convex hull. We prove a runtime bound of
$O(\Delta \cdot n^{3/2})$ for any three-dimensional contracting strategy, where
$\Delta$ denotes the diameter of the initial configuration. This comes up to a
factor of $\sqrt{n}$ close to the lower bound of $\Omega (\Delta \cdot n)$
which is already true in two dimensions. In general, it might be hard for
robots with limited viewing range to decide whether they are located on the
global convex hull and which movement maintains the connectivity of the swarm,
rendering the design of concrete contracting strategies a challenging task. We
prove that the continuous variant of 3D-Go-To-The-Center is contracting and
keeps the swarm connected. Moreover, we give a simple design criterion for
three-dimensional contracting strategies that maintains the connectivity of the
swarm and introduce an exemplary strategy based on this criterion.
AU - Braun, Michael
AU - Castenow, Jannik
AU - Meyer auf der Heide, Friedhelm
ID - 16968
T2 - Proceedings of the 27th Conference on Structural Information and Communication Complexity (SIROCCO)
TI - Local Gathering of Mobile Robots in Three Dimensions
ER -
TY - CONF
AU - Bila, Eleni
AU - Doherty, Simon
AU - Dongol, Brijesh
AU - Derrick, John
AU - Schellhorn, Gerhard
AU - Wehrheim, Heike
ED - Gotsman, Alexey
ED - Sokolova, Ana
ID - 20274
T2 - Formal Techniques for Distributed Objects, Components, and Systems - 40th {IFIP} {WG} 6.1 International Conference, {FORTE} 2020, Held as Part of the 15th International Federated Conference on Distributed Computing Techniques, DisCoTec 2020, Valletta, Malta, June 15-19, 2020, Proceedings
TI - Defining and Verifying Durable Opacity: Correctness for Persistent Software Transactional Memory
VL - 12136
ER -
TY - JOUR
AU - Sharma, Arnab
AU - Wehrheim, Heike
ID - 20279
JF - CoRR
TI - Testing Monotonicity of Machine Learning Models
VL - abs/2002.12278
ER -
TY - CONF
AU - Günter, Heinrich
AU - Meschut, Gerson
ID - 20301
T2 - 73rd IIW Annual Assembly and International Conference
TI - Joining of high-strength steel grades in lightweight structures using single-stage resistance element welding on conventional resistance spot welding machines
ER -
TY - CONF
AU - Tornede, Alexander
AU - Wever, Marcel Dominik
AU - Hüllermeier, Eyke
ID - 20306
T2 - Workshop MetaLearn 2020 @ NeurIPS 2020
TI - Towards Meta-Algorithm Selection
ER -
TY - BOOK
AU - Göddecke, Johannes
AU - Meschut, Gerson
AU - Gude, Maik
AU - Lieberwirth, Holger
AU - Tekkaya, Erman
AU - Zaeh, Michael
AU - Stegelmann, Michael
AU - Müller, Michael
AU - Böhme, Kurt
AU - Krampitz, Thomas
AU - Zöllner, Mareen
AU - Hahn, Marlon
AU - Schmitz, Fabian
AU - Hofer, Andreas
AU - Grohmann, Sandra
ID - 20318
SN - 978-3867806435
TI - FOREL-Wegweiser: Handlungsempfehlungen für den ressourceneffizienten Leichtbau
ER -
TY - CONF
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
T2 - Proc. International Conference for High Performance Computing, Networking, Storage and Analysis (SC)
TI - A Submatrix-Based Method for Approximate Matrix Function Evaluation in the Quantum Chemistry Code CP2K
ER -
TY - CONF
AU - Klingler, Florian
AU - Hauptmeier, Fynn
AU - Sommer, Christoph
AU - Dressler, Falko
ID - 20440
T2 - 39th IEEE International Conference on Computer Communications (INFOCOM 2020), Poster Session
TI - An Open Source Approach to Field Testing of WLAN up to IEEE 802.11ad at 60 GHz Using Commodity Hardware
ER -
TY - JOUR
AU - Liêu, Minh Ly
AU - Pelster, Matthias
ID - 15744
JF - The Quarterly Review of Economics and Finance
SN - 1062-9769
TI - Framing and the disposition effect in a scopic regime
VL - 78
ER -