@inproceedings{44, abstract = {{Natural language software requirements descriptions enable end users to formulate their wishes and expectations for a future software product without much prior knowledge in requirements engineering. However, these descriptions are susceptible to linguistic inaccuracies such as ambiguities and incompleteness that can harm the development process. There is a number of software solutions that can detect deficits in requirements descriptions and partially solve them, but they are often hard to use and not suitable for end users. For this reason, we develop a software system that helps end-users to create unambiguous and complete requirements descriptions by combining existing expert tools and controlling them using automatic compensation strategies. In order to recognize the necessity of individual compensation methods in the descriptions, we have developed linguistic indicators, which we present in this paper. Based on these indicators, the whole text analysis pipeline is ad-hoc configured and thus adapted to the individual circumstances of a requirements description.}}, author = {{Bäumer, Frederik Simon and Geierhos, Michaela}}, booktitle = {{Proceedings of the 51st Hawaii International Conference on System Sciences}}, isbn = {{978-0-9981331-1-9}}, keywords = {{Software Product Lines: Engineering, Services, and Management, Ambiguities, Incompleteness, Natural Language Processing, Software Requirements}}, location = {{Big Island, Waikoloa Village}}, pages = {{5746--5755}}, title = {{{Flexible Ambiguity Resolution and Incompleteness Detection in Requirements Descriptions via an Indicator-based Configuration of Text Analysis Pipelines}}}, doi = {{10125/50609}}, year = {{2018}}, } @inproceedings{4999, author = {{Pauck, Felix and Bodden, Eric and Wehrheim, Heike}}, booktitle = {{Proceedings of the 2018 26th ACM Joint Meeting on European Software Engineering Conference and Symposium on the Foundations of Software Engineering - ESEC/FSE 2018}}, isbn = {{9781450355735}}, publisher = {{ACM Press}}, title = {{{Do Android taint analysis tools keep their promises?}}}, doi = {{10.1145/3236024.3236029}}, year = {{2018}}, } @inproceedings{5203, author = {{Krüger, Stefan and Späth, Johannes and Ali, Karim and Bodden, Eric and Mezini, Mira}}, booktitle = {{European Conference on Object-Oriented Programming (ECOOP)}}, keywords = {{ITSECWEBSITE, CROSSING}}, pages = {{10:1--10:27}}, title = {{{CrySL: An Extensible Approach to Validating the Correct Usage of Cryptographic APIs}}}, year = {{2018}}, } @inproceedings{5216, abstract = {{A fundamental problem for overlay networks is to safely exclude leaving nodes, i.e., the nodes requesting to leave the overlay network are excluded from it without affecting its connectivity. To rigorously study self-stabilizing solutions to this problem, the Finite Departure Problem (FDP) has been proposed [9]. In the FDP we are given a network of processes in an arbitrary state, and the goal is to eventually arrive at (and stay in) a state in which all leaving processes irrevocably decided to leave the system while for all weakly-connected components in the initial overlay network, all staying processes in that component will still form a weakly connected component. In the standard interconnection model, the FDP is known to be unsolvable by local control protocols, so oracles have been investigated that allow the problem to be solved [9]. To avoid the use of oracles, we introduce a new interconnection model based on relays. Despite the relay model appearing to be rather restrictive, we show that it is universal, i.e., it is possible to transform any weakly-connected topology into any other weakly-connected topology, which is important for being a useful interconnection model for overlay networks. Apart from this, our model allows processes to grant and revoke access rights, which is why we believe it to be of interest beyond the scope of this paper. We show how to implement the relay layer in a self-stabilizing way and identify properties protocols need to satisfy so that the relay layer can recover while serving protocol requests.}}, author = {{Scheideler, Christian and Setzer, Alexander}}, booktitle = {{Proceedings of the 20th International Symposium on Stabilization, Safety, and Security of Distributed Systems (SSS 2018)}}, location = {{Tokyo, Japan}}, title = {{{Relays: A New Approach for the Finite Departure Problem in Overlay Networks}}}, doi = {{10.1007/978-3-030-03232-6_16}}, year = {{2018}}, } @inproceedings{5222, abstract = {{We present a self-stabilizing protocol for an overlay network that constructs the Minimum Spanning Tree (MST) for an underlay that is modeled by a weighted tree. The weight of an overlay edge between two nodes is the weighted length of their shortest path in the tree. We rigorously prove that our protocol works correctly under asynchronous and non-FIFO message delivery. Further, the protocol stabilizes after O(N^2) asynchronous rounds where N is the number of nodes in the overlay. }}, author = {{Götte, Thorsten and Scheideler, Christian and Setzer, Alexander}}, booktitle = {{Proceedings of the 20th International Symposium on Stabilization, Safety, and Security of Distributed Systems (SSS 2018)}}, location = {{Tokyo, Japan}}, pages = {{50--64}}, publisher = {{Springer}}, title = {{{On Underlay-Aware Self-Stabilizing Overlay Networks}}}, volume = {{11201}}, year = {{2018}}, } @article{5330, abstract = {{In Internet transactions, customers and service providers often interact once and anonymously. To prevent deceptive behavior a reputation system is particularly important to reduce information asymmetries about the quality of the offered product or service. In this study we examine the effectiveness of a reputation system to reduce information asymmetries when customers may make mistakes in judging the provided service quality. In our model, a service provider makes strategic quality choices and short-lived customers are asked to evaluate the observed quality by providing ratings to a reputation system. The customer is not able to always evaluate the service quality correctly and possibly submits an erroneous rating according to a predefined probability. Considering reputation profiles of the last three sales, within the theoretical model we derive that the service provider’s dichotomous quality decisions are independent of the reputation profile and depend only on the probabilities of receiving positive and negative ratings when providing low or high quality. Thus, a service provider optimally either maintains a good reputation or completely refrains from any reputation building process. However, when mapping our theoretical model to an experimental design we find that a significant share of subjects in the role of the service provider deviates from optimal behavior and chooses actions which are conditional on the current reputation profile. With respect to these individual quality choices we see that subjects use milking strategies which means that they exploit a good reputation. In particular, if the sales price is high, low quality is delivered until the price drops below a certain threshold, and then high quality is chosen until the price increases again.}}, author = {{Mir Djawadi, Behnud and Fahr, Rene and Haake, Claus-Jochen and Recker, Sonja}}, issn = {{1932-6203}}, journal = {{PLoS ONE}}, number = {{11}}, publisher = {{Public Library of Science}}, title = {{{Maintaining vs. Milking Good Reputation when Customer Feedback is Inaccurate}}}, doi = {{10.1371/journal.pone.0207172}}, volume = {{13}}, year = {{2018}}, } @misc{5368, author = {{Jochmaring, Moritz}}, publisher = {{Universität Paderborn}}, title = {{{Monotone Suchbarkeit bei den selbststabilisierenden Protokollen Build-List und Build-Multilist mit systemverlassenden Knoten}}}, year = {{2018}}, } @misc{5403, author = {{Geromel, Marcel}}, publisher = {{Universität Paderborn}}, title = {{{Mobile Facility Leasing}}}, year = {{2018}}, } @misc{5404, author = {{Kolpaczki, Patrick Irenäus}}, publisher = {{Universität Paderborn}}, title = {{{Online Algorithmen für das k-Page Migration Problem}}}, year = {{2018}}, } @misc{5414, author = {{Filmwala, Tasneem}}, publisher = {{Universität Paderborn}}, title = {{{Study Effects of Approximation on Conjugate Gradient Algorithm and Accelerate it on FPGA Platform}}}, year = {{2018}}, } @misc{5421, author = {{Gadewar, Onkar}}, publisher = {{Universität Paderborn}}, title = {{{Programmable Programs? - Designing FPGA Overlay Architectures with OpenCL}}}, year = {{2018}}, } @misc{5422, author = {{Diemke, Viktoria}}, publisher = {{Universität Paderborn}}, title = {{{Vertrauen und Vertrauenswürdigkeit - Akteure auf Cloud-basierten Plattformen}}}, year = {{2018}}, } @inproceedings{5530, abstract = {{Software companies nowadays create ecosystems of users and third-party providers around their platforms. They often provide online stores so that the third-party developments can be exposed to users directly. The resulting ecosystems differ significantly from each other in their architectural designs because their providers differ in terms of business goals and contexts. Until now, this architectural diversity and rationale behind it are not well-understood. Therefore, it is not clear which software features contribute to ecosystem’s success with respect to certain business goals and context. This hinders systematic creation of ecosystems in the future. Thus, decision-making becomes too risky; for future ecosystem providers, which may lead to creation of inefficient ecosystems that lack critical features, and for third-party providers to rely on ad-hoc choices while deciding on suitability of an ecosystem for their future career. In this paper, we introduce three design patterns for store- oriented software ecosystems by classifying the design decisions, business goals, and context of 111 store-oriented software ecosystems. Each design pattern provides an architectural solution to achieve a different business goal while supporting a different context. We discuss how the design patterns are applied together in order to achieve more business goals. Our work supports ecosystem and third-party providers by sharing practice-proven architectural solutions, helping them to take informed architectural decisions and reduce technical risks.}}, author = {{Jazayeri, Bahar and Zimmermann, Olaf and Küster, Jochen and Engels, Gregor and Kundisch, Dennis and Szopinski, Daniel}}, booktitle = {{The Latin American Conference on Pattern Languages of Programs (SLPLoP)}}, publisher = {{ACM. To appear}}, title = {{{Patterns of Store-oriented Software Ecosystems: Detection, Classification, and Analysis of Design Options}}}, year = {{2018}}, } @inproceedings{5547, author = {{Lösch, Achim and Platzner, Marco}}, booktitle = {{2018 IEEE 29th International Conference on Application-specific Systems, Architectures and Processors (ASAP)}}, isbn = {{9781538674796}}, location = {{Milan, Italy}}, publisher = {{IEEE}}, title = {{{A Highly Accurate Energy Model for Task Execution on Heterogeneous Compute Nodes}}}, doi = {{10.1109/asap.2018.8445098}}, year = {{2018}}, } @inproceedings{6483, author = {{Peuster, Manuel and Schneider, Stefan Balthasar and Christ, Frederic and Karl, Holger}}, booktitle = {{IEEE Conference on Network Function Virtualisation and Software Defined Networks (NFV-SDN) 5GNetApp}}, location = {{Verona}}, publisher = {{IEEE}}, title = {{{A Prototyping Platform to Validate and Verify Network Service Header-based Service Chains}}}, year = {{2018}}, } @phdthesis{6597, author = {{Juhnke, Jakob}}, publisher = {{Universität Paderborn}}, title = {{{Models and Constructions for Secure Reputation Systems}}}, doi = {{10.17619/UNIPB/1-570}}, year = {{2018}}, } @article{669, abstract = {{We study a new class of games which generalizes congestion games andits bottleneck variant. We introduce congestion games with mixed objectives to modelnetwork scenarios in which players seek to optimize for latency and bandwidths alike.We characterize the (non-)existence of pure Nash equilibria (PNE), the convergenceof improvement dynamics, the quality of equilibria and show the complexity of thedecision problem. For games that do not possess PNE we give bounds on the approx-imation ratio of approximate pure Nash equilibria.}}, author = {{Feldotto, Matthias and Leder, Lennart and Skopalik, Alexander}}, issn = {{1382-6905}}, journal = {{Journal of Combinatorial Optimization}}, number = {{4}}, pages = {{1145--1167}}, publisher = {{Springer Nature}}, title = {{{Congestion games with mixed objectives}}}, doi = {{10.1007/s10878-017-0189-y}}, volume = {{36}}, year = {{2018}}, } @inproceedings{6970, abstract = {{Dynamic allocation of resources is a key feature in network function virtualization (NFV), enabling flexible adjustment of slices and contained network services to ever-changing service demands. Considering resource allocation across the entire network, many authors have proposed approaches to optimize the placement and chaining of virtual network function (VNF) instances and the allocation of resources to these VNF instances. In doing so, various optimization objectives are conceivable, e.g., minimizing certain required resources or the end-to-end delay of the placed services. In this paper, we investigate the relationship between four typical optimization objectives when coordinating the placement and resource allocation of chained VNF instances. We observe an interesting trade-off between minimizing the overhead of starting/stopping VNF instances and all other objectives when adapting to changed service demands.}}, author = {{Schneider, Stefan Balthasar and Dräxler, Sevil and Karl, Holger}}, booktitle = {{IEEE Global Communications Conference (GLOBECOM 2018)}}, location = {{Abu Dhabi, UAE}}, publisher = {{IEEE}}, title = {{{Trade-offs in Dynamic Resource Allocation in Network Function Virtualization}}}, year = {{2018}}, } @inproceedings{6972, abstract = {{In recent years, a variety of different approaches have been proposed to tackle the problem of scaling and placing network services, consisting of interconnected virtual network functions (VNFs). This paper presents a placement abstraction layer (PAL) that provides a clear and simple northbound interface for using such algorithms while hiding their internal functionality and implementation. Through its southbound interface, PAL can connect to different back ends that evaluate the calculated placements, e.g., using simulations, emulations, or testbed approaches. As an example for such evaluation back ends, we introduce a novel placement emulation framework (PEF) that allows executing calculated placements using real, containerbased VNFs on real-world network topologies. In a case study, we show how PAL and PEF facilitate reusing and evaluating placement algorithms as well as validating their underlying models and performance claims.}}, author = {{Schneider, Stefan Balthasar and Peuster, Manuel and Karl, Holger}}, booktitle = {{IEEE Conference on Network Function Virtualization and Software Defined Networks (NFV-SDN 2018)}}, location = {{Verona, Italy}}, publisher = {{IEEE}}, title = {{{A Generic Emulation Framework for Reusing and Evaluating VNF Placement Algorithms}}}, doi = {{10.1109/NFV-SDN.2018.8725795}}, year = {{2018}}, } @inproceedings{6974, abstract = {{A key challenge of network function virtualization (NFV) is the complexity of developing and deploying new network services. Currently, development requires many manual steps that are time-consuming and error-prone (e.g., for creating service descriptors). Furthermore, existing management and orchestration (MANO) platforms only offer limited support of standardized descriptor models or package formats, limiting the re-usability of network services. To this end, we introduce a fully integrated, open-source NFV service development kit (SDK) with multi-MANO platform support. Our SDK simplifies many NFV service development steps by offering initial generation of descriptors, advanced project management, as well as fully automated packaging and submission for on-boarding. To achieve multi-platform support, we present a package format that extends ETSI’s VNF package format. In this demonstration, we present the end-to-end workflow to develop an NFV service that is then packaged for multiple platforms, i.e., 5GTANGO and OSM.}}, author = {{Schneider, Stefan Balthasar and Peuster, Manuel and Tavernier, Wouter and Karl, Holger}}, booktitle = {{IEEE Conference on Network Function Virtualization and Software Defined Networks (NFV-SDN 2018)}}, location = {{Verona, Italy}}, publisher = {{IEEE}}, title = {{{A Fully Integrated Multi-Platform NFV SDK}}}, doi = {{10.1109/NFV-SDN.2018.8725794}}, year = {{2018}}, }