@inproceedings{9270, abstract = {{As 5G and network function virtualization (NFV) are maturing, it becomes crucial to demonstrate their feasibility and benefits by means of vertical scenarios. While 5GPPP has identified smart manufacturing as one of the most important vertical industries, there is still a lack of specific, practical use cases. Using the experience from a large-scale manufacturing company, Weidm{\"u}ller Group, we present a detailed use case that reflects the needs of real-world manufacturers. We also propose an architecture with specific network services and virtual network functions (VNFs) that realize the use case in practice. As a proof of concept, we implement the required services and deploy them on an emulation-based prototyping platform. Our experimental results indicate that a fully virtualized smart manufacturing use case is not only feasible but also reduces machine interconnection and configuration time and thus improves productivity by orders of magnitude.}}, author = {{Schneider, Stefan Balthasar and Peuster, Manuel and Behnke, Daniel and Marcel, Müller and Bök, Patrick-Benjamin and Karl, Holger}}, booktitle = {{European Conference on Networks and Communications (EuCNC)}}, keywords = {{5g, vertical, smart manufacturing, nfv}}, publisher = {{IEEE}}, title = {{{Putting 5G into Production: Realizing a Smart Manufacturing Vertical Scenario}}}, doi = {{10.1109/eucnc.2019.8802016}}, year = {{2019}}, } @inproceedings{9275, abstract = {{In the last years, store-oriented software ecosystems are gaining more and more attention from a business perspective. In these ecosystems, third-party developers upload extensions to a store which can be downloaded by end users. While the functional scope of such ecosystems is relatively similar, the underlying business models differ greatly in and between their different product domains (e.g. Mobile Phone, Smart TV). This variability, in turn, makes it challenging for store providers to find a business model that fits their own needs. To handle this variability, we introduce the Business Variability Model (BVM) for modeling business model decisions. The basis of these decisions is the analysis of 60 store-oriented software ecosystems in eight different product domains. We map their business model decisions to the Business Model Canvas, condense them to a variability model and discuss particular variants and their dependencies. Our work provides store providers a new approach for modeling business model decisions together with insights of existing business models. This, in turn, supports them in creating new and improving existing business models.}}, author = {{Gottschalk, Sebastian and Rittmeier, Florian and Engels, Gregor}}, booktitle = {{Business Modeling and Software Design}}, editor = {{Shishkov, Boris}}, keywords = {{Software Ecosystems, Business Models, Variabilities}}, location = {{Lisbon}}, pages = {{153--169}}, publisher = {{Springer International Publishing}}, title = {{{Business Models of Store-Oriented Software Ecosystems: A Variability Modeling Approach}}}, doi = {{10.1007/978-3-030-24854-3_10}}, year = {{2019}}, } @inproceedings{7752, author = {{Sharma, Arnab and Wehrheim, Heike}}, booktitle = {{Proceedings of the Software Engineering Conference (SE)}}, isbn = {{978-3-88579-686-2}}, location = {{Stuttgart}}, pages = {{157 -- 158}}, publisher = {{Gesellschaft für Informatik e.V. (GI)}}, title = {{{Testing Balancedness of ML Algorithms}}}, volume = {{P-292}}, year = {{2019}}, } @article{80, abstract = {{Models on network formation have often been extended to include the potential of network disruption in recent years. Whereas the theoretical research on network formation under the threat of disruption has thus gained prominence, hardly any experimental research exists so far. In this paper, we therefore experimentally study the emergence of networks including the aspect of a known external threat by relating theoretical predictions by Dzuibiński and Goyal (2013) to actual observed behaviour. We deal with the question if subjects in the role of a strategic Designer are able to form safe networks for least costs while facing a strategic Adversary who is going to attack their networks. Varying the costs for protecting nodes, we designed and tested two treatments with different predictions for the equilibrium network and investigated whether one of the least cost equilibrium networks was more likely to be reached. Furthermore, the influence of the subjects’ farsightedness on their decision-making process was elicited and analysed. We find that while subjects are able to build safe networks in both treatments, equilibrium networks are only built in one of the two treatments. In the other treatment, predominantly safe networks are built but they are not for least costs. Additionally, we find that farsightedness –as measured in our experiment– has no influence on whether subjects are able to build safe or least cost equilibrium networks. Two robustness settings with a reduced external threat or more liberties to modify the initial networks qualitatively confirm our results. Overall, in this experiment observed behaviour is only partially in line with the theoretical predictions by Dzuibiński and Goyal (2013).}}, author = {{Endres, Angelika Elfriede and Recker, Sonja and Mir Djawadi, Behnud and Hoyer, Britta}}, journal = {{Journal of Economic Behavior and Organization }}, pages = {{708--734}}, title = {{{Network Formation and Disruption - An Experiment: Are equilibrium networks too complex?}}}, doi = {{10.1016/j.jebo.2018.11.004}}, volume = {{157}}, year = {{2019}}, } @phdthesis{8080, abstract = {{This thesis investigates approximate pure Nash equilibria in different game-theoretic models. In such an outcome, no player can improve her objective by more than a given factor through a deviation to another strategy. In the first part, we investigate two variants of Congestion Games in which the existence of pure Nash equilibria is guaranteed through a potential function argument. However, the computation of such equilibria might be hard. We construct and analyze approximation algorithms that enable the computation of states with low approximation factors in polynomial time. To show their guarantees we use sub games among players, bound the potential function values of arbitrary states and exploit a connection between Shapley and proportional cost shares. Furthermore, we apply and analyze sampling techniques for the computation of approximate Shapley values in different settings. In the second part, we concentrate on the existence of approximate pure Nash equilibria in games in which no pure Nash equilibria exist in general. In the model of Coevolving Opinion Formation Games, we bound the approximation guarantees for natural states nearly independent of the specific definition of the players' neighborhoods by applying a concept of virtual costs. For the special case of only one influential neighbor, we even show lower approximation factors for a natural strategy. Then, we investigate a two-sided Facility Location Game among facilities and clients on a line with an objective function consisting of distance and load. We show tight bounds on the approximation factor for settings with three facilities and infinitely many clients. For the general scenario with an arbitrary number of facilities, we bound the approximation factor for two promising candidates, namely facilities that are uniformly distributed and which are paired.}}, author = {{Feldotto, Matthias}}, title = {{{Approximate Pure Nash Equilibria in Congestion, Opinion Formation and Facility Location Games}}}, doi = {{10.17619/UNIPB/1-588}}, year = {{2019}}, } @article{8113, abstract = {{The ongoing softwarization of networks creates a big need for automated testing solutions to ensure service quality. This becomes even more important if agile environments with short time to market and high demands, in terms of service performance and availability, are considered. In this paper, we introduce a novel testing solution for virtualized, microservice-based network functions and services, which we base on TTCN-3, a well known testing language defined by the European standards institute (ETSI). We use TTCN-3 not only for functional testing but also answer the question whether TTCN-3 can be used for performance profiling tasks as well. Finally, we demonstrate the proposed concepts and solutions in a case study using our open-source prototype to test and profile a chained network service.}}, author = {{Peuster, Manuel and Dröge, Christian and Boos, Clemens and Karl, Holger}}, issn = {{2405-9595}}, journal = {{ICT Express}}, publisher = {{Elsevier BV}}, title = {{{Joint testing and profiling of microservice-based network services using TTCN-3}}}, doi = {{10.1016/j.icte.2019.02.001}}, year = {{2019}}, } @inproceedings{8240, author = {{Dräxler, Sevil and Karl, Holger}}, booktitle = {{5th IEEE International Conference on Network Softwarization (NetSoft) 2019}}, location = {{Paris}}, title = {{{SPRING: Scaling, Placement, and Routing of Heterogeneous Services with Flexible Structures}}}, year = {{2019}}, } @misc{8312, author = {{Bäumer, Frederik Simon and Geierhos, Michaela}}, booktitle = {{encyclopedia.pub}}, keywords = {{OTF Computing, Natural Language Processing, Requirements Engineering}}, publisher = {{MDPI}}, title = {{{Requirements Engineering in OTF-Computing}}}, year = {{2019}}, } @article{7413, author = {{Gutt, Dominik and Neumann, Jürgen and Zimmermann, Steffen and Kundisch, Dennis and Chen, J.}}, journal = {{Journal of Strategic Information Systems}}, number = {{2}}, pages = {{104--117}}, title = {{{Design of Review Systems – A Strategic Instrument to shape Online Reviewing Behavior and Economic Outcomes}}}, volume = {{28}}, year = {{2019}}, } @misc{7623, author = {{Zhang, Shikun}}, pages = {{64}}, publisher = {{Universität Paderborn}}, title = {{{Combining Android Apps for Analysis Purposes}}}, year = {{2019}}, } @misc{7628, author = {{Selbach, Nils}}, publisher = {{Universität Paderborn}}, title = {{{Modeling Crypto API usages in OpenSSL's EVP library}}}, year = {{2019}}, } @techreport{7630, abstract = {{In this paper, we analyze a credence goods model adjusted to the health care market with regulated prices and heterogeneous experts. Experts are physicians and are assumed to differ in their cost of treating a small problem. We investigate the effects of this heterogeneity on the physicians’ level of fraud and on the patients’ search for second opinions. We find that introducing a fraction of more efficient low-cost physicians always increases social welfare, but in some cases only because of the raised physicians’ surplus. When the low-cost physicians’ cost advantage is small, imposing a share of low-cost physicians does not change the equilibrium fraud level. When the cost advantage is large, however, different changes in the fraud level occur depending on the share of generated low-cost physicians, the search rate and the initial level of fraud.}}, author = {{Heinzel, Joachim Maria Josef}}, keywords = {{credence goods, treatment efficiency, heterogeneous experts, overcharging}}, publisher = {{CIE Working Paper Series}}, title = {{{Credence Goods Markets with Heterogeneous Experts}}}, volume = {{118}}, year = {{2019}}, } @inproceedings{7635, author = {{Sharma, Arnab and Wehrheim, Heike}}, booktitle = {{IEEE International Conference on Software Testing, Verification and Validation (ICST)}}, location = {{Xi'an, China, April, 2019}}, pages = {{125----135}}, publisher = {{IEEE}}, title = {{{Testing Machine Learning Algorithms for Balanced Data Usage}}}, year = {{2019}}, } @inproceedings{7636, abstract = {{Self-stabilizing overlay networks have the advantage of being able to recover from illegal states and faults. However, the majority of these networks cannot give any guarantees on their functionality while the recovery process is going on. We are especially interested in searchability, i.e., the functionality that search messages for a specific node are answered successfully if a node exists in the network. In this paper we investigate overlay networks that ensure the maintenance of monotonic searchability while the self-stabilization is going on. More precisely, once a search message from node u to another node v is successfully delivered, all future search messages from u to v succeed as well. We extend the existing research by focusing on skip graphs and present a solution for two scenarios: (i) the goal topology is a super graph of the perfect skip graph and (ii) the goal topology is exactly the perfect skip graph. }}, author = {{Luo, Linghui and Scheideler, Christian and Strothmann, Thim Frederik}}, booktitle = {{Proceedings of the 2019 IEEE 33rd International Parallel and Distributed Processing Symposium (IPDPS '19)}}, location = {{Rio de Janeiro, Brazil}}, title = {{{MultiSkipGraph: A Self-stabilizing Overlay Network that Maintains Monotonic Searchability}}}, year = {{2019}}, } @inproceedings{7668, author = {{Heindorf, Stefan and Scholten, Yan and Engels, Gregor and Potthast, Martin}}, booktitle = {{WWW}}, location = {{San Francisco, USA}}, pages = {{670--680}}, publisher = {{ACM}}, title = {{{Debiasing Vandalism Detection Models at Wikidata}}}, doi = {{10.1145/3308558.3313507}}, year = {{2019}}, } @article{7689, author = {{Riebler, Heinrich and Vaz, Gavin Francis and Kenter, Tobias and Plessl, Christian}}, journal = {{ACM Trans. Archit. Code Optim. (TACO)}}, keywords = {{htrop}}, number = {{2}}, pages = {{14:1–14:26}}, publisher = {{ACM}}, title = {{{Transparent Acceleration for Heterogeneous Platforms with Compilation to OpenCL}}}, doi = {{10.1145/3319423}}, volume = {{16}}, year = {{2019}}, } @misc{8351, author = {{Nutt, Florian}}, title = {{{Vertrauensbildung und Reputationssysteme auf digitalen B2B-Märkten - Ein klassifizierender Überblick}}}, year = {{2019}}, } @article{8424, abstract = {{The vision of On-the-Fly (OTF) Computing is to compose and provide software services ad hoc, based on requirement descriptions in natural language. Since non-technical users write their software requirements themselves and in unrestricted natural language, deficits occur such as inaccuracy and incompleteness. These deficits are usually met by natural language processing methods, which have to face special challenges in OTF Computing because maximum automation is the goal. In this paper, we present current automatic approaches for solving inaccuracies and incompletenesses in natural language requirement descriptions and elaborate open challenges. In particular, we will discuss the necessity of domain-specific resources and show why, despite far-reaching automation, an intelligent and guided integration of end users into the compensation process is required. In this context, we present our idea of a chat bot that integrates users into the compensation process depending on the given circumstances. }}, author = {{Bäumer, Frederik Simon and Kersting, Joschka and Geierhos, Michaela}}, issn = {{2073-431X}}, journal = {{Computers}}, keywords = {{Inaccuracy Detection, Natural Language Software Requirements, Chat Bot}}, location = {{Vilnius, Lithuania}}, number = {{1}}, publisher = {{MDPI AG, Basel, Switzerland}}, title = {{{Natural Language Processing in OTF Computing: Challenges and the Need for Interactive Approaches}}}, doi = {{10.3390/computers8010022}}, volume = {{8}}, year = {{2019}}, } @misc{8530, author = {{Beckhoff, Yvonne Maria}}, title = {{{There's an App for that - Ein Literaturüberblick über Erfolgsfaktoren für App-Downloads}}}, year = {{2019}}, } @inproceedings{8534, abstract = {{We propose two protocols for distributed priority queues (denoted by 'heap' for simplicity in this paper) called SKEAP and SEAP. SKEAP realizes a distributed heap for a constant amount of priorities and SEAP one for an arbitrary amount. Both protocols build on an overlay, which induces an aggregation tree on which heap operations are aggregated in batches, ensuring that our protocols scale even for a high rate of incoming requests. As part of SEAP we provide a novel distributed protocol for the k-selection problem that runs in time O(log n) w.h.p. SKEAP guarantees sequential consistency for its heap operations, while SEAP guarantees serializability. SKEAP and SEAP provide logarithmic runtimes w.h.p. on all their operations. SKEAP and SEAP provide logarithmic runtimes w.h.p. on all their operations with SEAP having to use only O(log n) bit messages.}}, author = {{Feldmann, Michael and Scheideler, Christian}}, booktitle = {{Proceedings of the 31st ACM Symposium on Parallelism in Algorithms and Architectures (SPAA)}}, pages = {{287----296}}, publisher = {{ACM}}, title = {{{Skeap & Seap: Scalable Distributed Priority Queues for Constant and Arbitrary Priorities}}}, doi = {{10.1145/3323165.3323193}}, year = {{2019}}, }