@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{9276, author = {{Yigitbas, Enes and Josifovska, Klementina and Jovanovikj, Ivan and Kalinci, Ferhat and Anjorin, Anthony and Engels, Gregor}}, booktitle = {{Proceedings of the 11th ACM SIGCHI Symposium on Engineering Interactive Computing Systems (EICS 2019)}}, location = {{Valencia}}, pages = {{13:1----13:7}}, title = {{{Component-Based Development of Adaptive User Interfaces }}}, 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}}, } @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}}, } @inbook{7430, author = {{Rittmeier, Florian and Engels, Gregor and Teetz, Alexander}}, booktitle = {{Business Process Management Workshops}}, editor = {{Daniel, Florian and Sheng, Quan Z. and Motahari, Hamid}}, isbn = {{9783030116408}}, issn = {{1865-1348}}, pages = {{531--542}}, publisher = {{Springer International Publishing}}, title = {{{Process Weakness Patterns for the Identification of Digitalization Potentials in Business Processes}}}, doi = {{10.1007/978-3-030-11641-5_42}}, volume = {{342}}, 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}}, } @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}}, } @inproceedings{7669, author = {{Josifovska, Klementina and Yigitbas, Enes and Engels, Gregor}}, booktitle = {{Proceedings of the 21st International Conference on Human-Computer Interaction (HCII 2019)}}, location = {{Orlando, Florida}}, pages = {{398--409}}, publisher = {{Springer, LNCS}}, title = {{{A Digital Twin-Based Multi-Modal UI Adaptation Framework for Assistance Systems in Industry 4.0 }}}, volume = {{11568}}, 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}}, } @inproceedings{8495, author = {{Josifovska, Klementina and Yigitbas, Enes and Engels, Gregor}}, booktitle = {{Proceedings of 5th International Workshop on Software Engineering for Smart Cyber-Physical Systems (SEsCPS'19)}}, location = {{Montreal, Canada}}, pages = {{25--31}}, publisher = {{IEEE Press}}, title = {{{ Reference Framework for Digital Twins within Cyber-Physical Systems }}}, 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}}, } @article{8543, abstract = {{Dieser Artikel erörtert, ob in studentischen Kleingruppenprojekten in der Informatik Kreativität und die Erarbeitung kreativer Ideen explizit gefördert werden kann. Dazu wird ein Seminarkonzept detailliert vorgestellt, welches auf zwei Grundkonzepten der Informatikpraxis beruht: agiles Projektvorgehen und Prototyping. Die Teilnehmenden des Seminars wurden gezielt in einen Kreativitätsprozess geleitet, indem sie für gegebene moderne Technologien (Virtual Reality, Augmented Reality, Drohnen, etc.) neuartige Nutzungsszenarien entwickeln sollten. Um zu evaluieren, ob das Lehrkonzept erfolgreich ist, wird sowohl die produktbezogene als auch die prozessbezogene Kreativität betrachtet. Für die produktbezogene Kreativität werden die von den Teilnehmenden erstellten Projektideen inklusive der benutzten Prototypingtechnik vorgestellt und bewertet. Die Teilnehmenden haben nicht nur eine enorme Breite an Ideen entwickelt (in der Summe ca. 40 bei 16 Teilnehmenden), sondern insbesondere auch acht Ideen im Verlaufe des Seminars sehr konkret weiterentwickelt. Hinsichtlich der prozessbezogenen Kreativität wird das Lehrkonzept durch mehrere Fragebögen eruiert. Die Studierenden sind mit dem Seminar, der Herangehensweise und den Ergebnissen sehr zufrieden, was unter anderem durch die äußerst positive studentische Veranstaltungskritik (u.a. 1,0 für den Gesamteindruck sowie Atmosphäre in der Veranstaltung) und die Auswertung der Evaluationsfragebögen unterstrichen wird. Auch von externen Beobachtern werden die erarbeiteten Ergebnisse und der Einsatz von Prototyping als sehr positiv bewertet.}}, author = {{Strothmann, Thim Frederik}}, journal = {{die hochschullehre}}, title = {{{Förderung von Kreativität in studentischen Kleingruppenprojekten in der Informatik – Ein Prototyping-basierter Ansatz}}}, year = {{2019}}, } @article{8638, author = {{Yigitbas, Enes and Schomaker, Gunnar}}, journal = {{International Tube Association (ITAtube) Journal}}, title = {{{WindCORES - Digital Transformation with Renewable Energy }}}, year = {{2019}}, } @inproceedings{8792, abstract = {{5G together with software defined networking (SDN) and network function virtualisation (NFV) will enable a wide variety of vertical use cases. One of them is the smart man- ufacturing case which utilises 5G networks to interconnect production machines, machine parks, and factory sites to enable new possibilities in terms of flexibility, automation, and novel applications (industry 4.0). However, the availability of realistic and practical proof-of-concepts for those smart manufacturing scenarios is still limited. This demo fills this gap by not only showing a real-world smart manufacturing application entirely implemented using NFV concepts, but also a lightweight prototyping framework that simplifies the realisation of vertical NFV proof-of-concepts. Dur- ing the demo, we show how an NFV-based smart manufacturing scenario can be specified, on-boarded, and instantiated before we demonstrate how the presented NFV services simplify machine data collection, aggregation, and analysis.}}, author = {{Peuster, Manuel and Schneider, Stefan Balthasar and Behnke, Daniel and Müller, Marcel and Bök, Patrick-Benjamin and Karl, Holger}}, booktitle = {{5th IEEE International Conference on Network Softwarization (NetSoft 2019)}}, location = {{Paris}}, title = {{{Prototyping and Demonstrating 5G Verticals: The Smart Manufacturing Case}}}, doi = {{10.1109/NETSOFT.2019.8806685}}, year = {{2019}}, }