@inproceedings{2344, author = {{Blömer, Johannes and Günther, Peter and Krummel, Volker and Löken, Nils}}, booktitle = {{Foundations and Practice of Security}}, isbn = {{9783319756493}}, issn = {{0302-9743}}, pages = {{3--17}}, publisher = {{Springer International Publishing}}, title = {{{Attribute-Based Encryption as a Service for Access Control in Large-Scale Organizations}}}, doi = {{10.1007/978-3-319-75650-9_1}}, year = {{2017}}, } @misc{18027, author = {{Banh, Ngoc Chi}}, publisher = {{Universität Paderborn}}, title = {{{An Asynchronous Adaption of a Churn-resistant Overlay Network}}}, year = {{2017}}, } @inproceedings{91, abstract = {{The interest in business model innovation has risen rapidly in recent years, and software tools for business model development hold great promise for supporting business model innovation. Nonetheless, virtually no design-relevant knowledge exists concerning the functions that such tools should possess. Therefore, we develop a comprehensive taxonomy that identifies characteristic functions of software-based business model development tools. For developing the taxonomy, we draw on prior research on business model innovation, process modeling, and creativity support systems, and we analyze software tools for business model development that have been proposed in practice. The resulting taxonomy can support practitioners in their tool (re-)design and investment decisions, and for researchers can serve as a preliminary step towards more advanced theories for software tools for business model development.}}, author = {{Szopinski, Daniel and Schoormann, Thorsten and John, Thomas and Knackstedt, Ralf and Kundisch, Dennis}}, booktitle = {{Proceedings of the 23rd Americas Conference on Information Systems (AMCIS)}}, location = {{Boston, USA}}, title = {{{How Software Can Support Innovating Business Models: A Taxonomy of Functions of Business Model Development Tools}}}, year = {{2017}}, } @inproceedings{92, author = {{Szopinski, Daniel and Schoormann, Thorsten and John, Thomas and Knackstedt, Ralf and Kundisch, Dennis}}, booktitle = {{Bosch Business Model Innovation Summit 2017}}, location = {{Renningen, Germany}}, title = {{{How Software Can Support Innovating Business Models: A Taxonomy of Functions of Business Model Development Tools}}}, year = {{2017}}, } @misc{94, author = {{Martens, Martin}}, publisher = {{Universität Paderborn}}, title = {{{Geschäftsmodelle elektronischer Handelsplattformen}}}, year = {{2017}}, } @misc{95, author = {{Kundisch, Dennis and John, Thomas}}, booktitle = {{Enzyklopädie der Wirtschaftsinformatik, GITO}}, title = {{{Geschäftsmodell-Modellierungssprache/Business Model Modeling Language}}}, year = {{2017}}, } @inproceedings{77, abstract = {{Das Enterprise Architecture Management stellt umfangreiche Methoden, Modelle und Frameworks f{\"u}r die Modellierung von Unternehmensarchitekturen zur Verf{\"u}gung. Die Entwicklung von Software und deren Integration in IT-Landschaften ist heutzutage zunehmend von Komplexit{\"a}t und Unsicherheit gepr{\"a}gt. Dieser Beitrag (Research-in-progress) m{\"o}chte ein neues Paradigma – das „On-The-Fly Computing“ – vorschlagen, um diesen Herausforderungen zu begegnen, m{\"o}gliche L{\"o}sungsans{\"a}tze zu diskutieren sowie erste Ergebnisse eines Referenzmodells f{\"u}r individualisierte IT-Dienstleistungen in dynamischen Software-M{\"a}rkten dokumentieren.}}, author = {{Szopinski, Daniel and Jazayeri, Bahar and Engels, Gregor and Kundisch, Dennis}}, booktitle = {{Proceedings of the Workshop Enterprise Architecture Management in Forschung und Praxis, INFORMATIK 2017, Chemnitz, Germany}}, pages = {{2059--2066}}, publisher = {{GI}}, title = {{{On-The-Fly Computing: Ein Referenzmodell für individualisierte IT-Dienstleistungen in dynamischen Märkten}}}, year = {{2017}}, } @inproceedings{78, abstract = {{The Internet of Things (IoT) connects the things of our everyday life and supports usin our common activities.Several markets for IoT services have been created. These markets enable IoT users to search and compose services in order to support an IoT activity.However, existing IoT markets like IFTTT (If This Then That) are not convenient for users with respect to service discovery and composition.The objective of On-the-fly (OTF) computing is to configure and provide software markets that fulfill individual users' wishes by the automatic on-the-fly composition of single services.The architecture framework of On-the-fly computing markets helps architects to systematically develop these systems in different domains.In this paper, we use our OTF architectural framework to examine the requirements of a reference architecture for IoT markets.Furthermore, we perform a comparison between the architecture of IFTTT as an existing IoT market with this reference architecture. The results show how existing IoT markets can be improved. In return, the practical knowledge of IFTTT is taken to the reference architecture.This knowledge helps to overcome the limitations of today's IoT markets or creating new markets in the future.}}, author = {{Jazayeri, Bahar and Schwichtenberg, Simon}}, booktitle = {{Proceedings of the International Conference on Software Architecture (ICSA) IoT-ASAP Workshop}}, pages = {{120----127}}, publisher = {{IEEE}}, title = {{{On-The-Fly Computing Meets IoT Markets - Towards a Reference Architecture}}}, doi = {{10.1109/ICSAW.2017.59}}, year = {{2017}}, } @inproceedings{79, abstract = {{Consider a problem in which $n$ jobs that are classified into $k$ types arrive over time at their release times and are to be scheduled on a single machine so as to minimize the maximum flow time.The machine requires a setup taking $s$ time units whenever it switches from processing jobs of one type to jobs of a different type.We consider the problem as an online problem where each job is only known to the scheduler as soon as it arrives and where the processing time of a job only becomes known upon its completion (non-clairvoyance).We are interested in the potential of simple ``greedy-like'' algorithms.We analyze a modification of the FIFO strategy and show its competitiveness to be $\Theta(\sqrt{n})$, which is optimal for the considered class of algorithms.For $k=2$ types it achieves a constant competitiveness.Our main insight is obtained by an analysis of the smoothed competitiveness.If processing times $p_j$ are independently perturbed to $\hat p_j = (1+X_j)p_j$, we obtain a competitiveness of $O(\sigma^{-2} \log^2 n)$ when $X_j$ is drawn from a uniform or a (truncated) normal distribution with standard deviation $\sigma$.The result proves that bad instances are fragile and ``practically'' one might expect a much better performance than given by the $\Omega(\sqrt{n})$-bound.}}, author = {{Mäcker, Alexander and Malatyali, Manuel and Meyer auf der Heide, Friedhelm and Riechers, Sören}}, booktitle = {{Proceedings of the 15th Workshop on Approximation and Online Algorithms (WAOA)}}, pages = {{207--222}}, publisher = {{Springer}}, title = {{{Non-Clairvoyant Scheduling to Minimize Max Flow Time on a Machine with Setup Times}}}, doi = {{10.1007/978-3-319-89441-6}}, volume = {{10787}}, year = {{2017}}, } @inproceedings{5695, author = {{Jazayeri, Bahar and Schwichtenberg, Simon}}, booktitle = {{Proceedings of Softwaretechnik-Trends Workshops}}, publisher = {{Gesellschaft für Informatik eV, Fachgruppe PARS}}, title = {{{On the Necessity of an Architecture Framework for On-The-Fly Computing}}}, volume = {{37}}, year = {{2017}}, } @article{58, abstract = {{Network function virtualization and software-defined networking allow services consisting of virtual network functions to be designed and implemented with great flexibility by facilitating automatic deployments, migrations, and reconfigurations for services and their components. For extended flexibility, we go beyond seeing services as a fixed chain of functions. We define the service structure in a flexible way that enables changing the order of functions in case the functionality of the service is not influenced by this, and propose a YANG data model for expressing this flexibility. Flexible structures allow the network orchestration system to choose the optimal composition of service components that for example gives the best results for placement of services in the network. When number of flexible services and number of components in each service increase, combinatorial explosion limits the practical use of this flexibility. In this paper, we describe a selection heuristic that gives a Pareto set of the possible compositions of a service as well as possible combinations of different services, with respect to different optimization objectives. Moreover, we present a heuristic algorithm for placement of a combination of services, which aims at placing service components along shortest paths that have enough capacity for accommodating the services. By applying these solutions, we show that allowing flexibility in the service structure is feasible.}}, author = {{Dräxler, Sevil and Karl, Holger}}, journal = {{International Journal of Network Management}}, number = {{2}}, pages = {{1----16}}, publisher = {{Wiley Online Library}}, title = {{{Specification, Composition, and Placement of Network Services with Flexible Structures}}}, doi = {{10.1002/nem.1963}}, year = {{2017}}, } @inproceedings{59, abstract = {{We consider a scheduling problem on $m$ identical processors sharing an arbitrarily divisible resource. In addition to assigning jobs to processors, the scheduler must distribute the resource among the processors (e.g., for three processors in shares of 20\%, 15\%, and 65\%) and adjust this distribution over time. Each job $j$ comes with a size $p_j \in \mathbb{R}$ and a resource requirement $r_j > 0$. Jobs do not benefit when receiving a share larger than $r_j$ of the resource. But providing them with a fraction of the resource requirement causes a linear decrease in the processing efficiency. We seek a (non-preemptive) job and resource assignment minimizing the makespan.Our main result is an efficient approximation algorithm which achieves an approximation ratio of $2 + 1/(m-2)$. It can be improved to an (asymptotic) ratio of $1 + 1/(m-1)$ if all jobs have unit size. Our algorithms also imply new results for a well-known bin packing problem with splittable items and a restricted number of allowed item parts per bin.Based upon the above solution, we also derive an approximation algorithm with similar guarantees for a setting in which we introduce so-called tasks each containing several jobs and where we are interested in the average completion time of tasks (a task is completed when all its jobs are completed).}}, author = {{Kling, Peter and Mäcker, Alexander and Riechers, Sören and Skopalik, Alexander}}, booktitle = {{Proceedings of the 29th ACM Symposium on Parallelism in Algorithms and Architectures (SPAA)}}, pages = {{123----132}}, title = {{{Sharing is Caring: Multiprocessor Scheduling with a Sharable Resource}}}, doi = {{10.1145/3087556.3087578}}, year = {{2017}}, } @misc{60, author = {{Niehus, David}}, publisher = {{Universität Paderborn}}, title = {{{Semantically Secure Attribute-based Searchable Encryption}}}, year = {{2017}}, } @misc{62, author = {{Weis, Eduard}}, publisher = {{Universität Paderborn}}, title = {{{Searchable Encryption}}}, year = {{2017}}, } @article{64, abstract = {{A current trend in networking and cloud computing is to provide compute resources at widely distributed sites; this is exemplified by developments such as Network Function Virtualisation. This paves the way for wide-area service deployments with improved service quality: e.g. user-perceived response times can be reduced by offering services at nearby sites. But always assigning users to the nearest site can be a bad decision if this site is already highly utilised. This paper formalises two related decisions of allocating compute resources at different sites and assigning users to them with the goal of minimising the response times while the total number of resources to be allocated is limited – a non-linear capacitated Facility Location Problem with integrated queuing systems. To efficiently handle its non-linearity, we introduce five linear problem linearisations and adapt the currently best heuristic for a similar scenario to our scenario. All six approaches are compared in experiments for solution quality and solving time. Surprisingly, our best optimisation formulation outperforms the heuristic in both time and quality. Additionally, we evaluate the influence of distributions of available compute resources in the network on the response time: The time was halved for some configurations. The presented formulation techniques for our problem linearisations are applicable to a broader optimisation domain.}}, author = {{Keller, Matthias and Karl, Holger}}, journal = {{IEEE Transactions on Network and Service Management}}, number = {{1}}, pages = {{121----135}}, publisher = {{IEEE}}, title = {{{Response-Time-Optimised Service Deployment: MILP Formulations of Piece-wise Linear Functions Approximating Non-linear Bivariate Mixed-integer Functions}}}, doi = {{10.1109/TNSM.2016.2611590}}, year = {{2017}}, } @inproceedings{49, abstract = {{A multiplicity of visual languages have been proposed for representing business models. These languages are claimed to facilitate tasks such as understanding, communicating, and innovating a business model; and have been developed rather independently by scholars from accounting, computer science, information systems, and strategy. Consequently, the existing approaches greatly differ and to some extent contradict each other, for example, regarding their understanding of the business model concept, their terminology, and their visual notations – which means there is little common ground for developing a cumulative stream of research. Therefore, we provide a systematic, cross-disciplinary review of this emerging field and synthesize the pragmatic, semantic, and syntactic foundations of the proposed approaches. Further, we derive an agenda for future research and discuss the challenges that lie ahead to advance the field.}}, author = {{John, Thomas and Kundisch, Dennis and Szopinski, Daniel}}, booktitle = {{Proceedings of the 38th International Conference on Information Systems (ICIS), Seoul, South Korea}}, title = {{{Visual Languages for Modeling Business Models: A Critical Review and Future Research Directions}}}, year = {{2017}}, } @misc{698, author = {{Banh, Ngoc Chi}}, publisher = {{Universität Paderborn}}, title = {{{As Asynchronous Adaption of a Churn-resistant Overlay Network}}}, year = {{2017}}, } @phdthesis{704, author = {{Riechers, Sören}}, publisher = {{Universität Paderborn}}, title = {{{Scheduling with Scarce Resources}}}, doi = {{10.17619/UNIPB/1-231}}, year = {{2017}}, } @article{706, author = {{Mäcker, Alexander and Malatyali, Manuel and Meyer auf der Heide, Friedhelm and Riechers, Sören}}, journal = {{Journal of Combinatorial Optimization}}, number = {{4}}, pages = {{1168--1194}}, publisher = {{Springer}}, title = {{{Cost-efficient Scheduling on Machines from the Cloud}}}, doi = {{10.1007/s10878-017-0198-x}}, volume = {{36}}, year = {{2017}}, } @inproceedings{717, abstract = {{In conventional large-scale networks, creation and management of network services are costly and complex tasks that often consume a lot of resources, including time and manpower. Network softwarization and network function virtualization have been introduced to tackle these problems, aiming at decreasing costs and complexity of implementing new services, maintaining the implemented services, and managing available resources in service provisioning platforms and underlying infrastructures. To experience the full potential of these approaches, innovative development support tools and service provisioning environments are needed. To answer these needs, we introduce the architecture of the open-source SONATA system, a service programming, orchestration, and management framework. We present a development toolchain for virtualized network services, fully integrated with a service platform and orchestration system. We introduce the modular and flexible architecture of our system and discuss its main components and features, such as function- and service-specific managers that allow fine-grained service management, slicing support to facilitate multi-tenancy, recursiveness for improved scalability, and full-featured DevOps support.}}, author = {{Dräxler, Sevil and Karl, Holger and Peuster, Manuel and Razzaghi Kouchaksaraei, Hadi and Bredel, Michael and Lessmann, Johannes and Soenen, Thomas and Tavernier, Wouter and Mendel-Brin, Sharon and Xilouris, George}}, booktitle = {{2017 IEEE International Conference on Communications Workshops (ICC Workshops)}}, isbn = {{9781509015252}}, location = {{Paris, France}}, publisher = {{IEEE}}, title = {{{SONATA: Service programming and orchestration for virtualized software networks}}}, doi = {{10.1109/iccw.2017.7962785}}, year = {{2017}}, }