@misc{51, author = {{Winkelhake, Nikolai}}, publisher = {{Universität Paderborn}}, title = {{{Tying und Bundling in digitalen Märkten - eine wettbewerbspolitische Analyse}}}, year = {{2017}}, } @inproceedings{52, author = {{John, Thomas and Szopinski, Daniel}}, booktitle = {{1st Business Model Conference}}, location = {{Venice, Italy}}, title = {{{Towards Explaining the Popularity of the Business Model Canvas: A Dual-coding Approach}}}, year = {{2017}}, } @inproceedings{5204, author = {{Späth, Johannes and Ali, Karim and Bodden, Eric}}, booktitle = {{2017 International Conference on Object-Oriented Programming, Languages and Applications (OOPSLA/SPLASH)}}, keywords = {{ATTRACT, ITSECWEBSITE, CROSSING}}, publisher = {{ACM Press}}, title = {{{IDEal: Efficient and Precise Alias-aware Dataflow Analysis}}}, year = {{2017}}, } @article{5209, author = {{Fischer, Andreas and Fuhry, Benny and Kerschbaum, Florian and Bodden, Eric}}, journal = {{CoRR}}, title = {{{Computation on Encrypted Data using Data Flow Authentication}}}, volume = {{abs/1710.00390}}, year = {{2017}}, } @inproceedings{53, abstract = {{Amongst the growing body of literature on the drivers of online ratings, the influence of customers’ local offline environment on their ratings has largely been neglected. This study examines the relationship between ratings made outside of a customer’s home area and the magnitude of online ratings. We employ a data-driven identification of a customer’s geographic home area and use variation in this variable to identify the consequences for the magnitude of ratings. In line with our theory, we find that customers who rate while traveling give, on average, higher ratings than locals. However, this relationship is moderated by the posting time of a review relative to consumption, as travelers post more negative ratings during or shortly after consumption. These relationships are most pronounced for customers who travel and rate less frequently. Our results come with substantial implications for a business’s average rating and for customer decision making. }}, author = {{Neumann, Jürgen and Gutt, Dominik and Kundisch, Dennis}}, booktitle = {{Proceedings of the 38th International Conference on Information Systems (ICIS)}}, location = {{Seoul, South Korea}}, title = {{{The Traveling Reviewer Problem – Exploring the Relationship Between Offline Locations and Online Rating Behavior}}}, year = {{2017}}, } @inproceedings{54, author = {{Neumann, Jürgen and Gutt, Dominik and Kundisch, Dennis}}, booktitle = {{INFORMS Annual Meeting}}, location = {{Houston, USA}}, title = {{{The Traveling Reviewer Problem – Exploring the Relationship between Offline Locations and Online Rating Behavior}}}, year = {{2017}}, } @inproceedings{55, abstract = {{We introduce the mobile server problem, inspired by current trends to move computational tasks from cloud structures to multiple devices close to the end user. An example for this are embedded systems in autonomous cars that communicate in order to coordinate their actions. Our model is a variant of the classical Page Migration Problem. Moreformally, we consider a mobile server holding a data page.The server can move in the Euclidean space (of arbitrary dimension). In every round, requests for data items from the page pop up at arbitrary points in the space. The requests are served, each at a cost of the distance from the requesting point and the server, and the mobile server may move, at a cost D times the distance traveled for some constant D . We assume a maximum distance m the server is allowed to move per round. We show that no online algorithm can achieve a competitive ratio independent of the length of the input sequence in this setting. Hence we augment the maximum movement distance of the online algorithms to ( 1 + δ) times the maximum distance of the offline solution. We provide a deterministic algorithm which is simple to describe and works for multiple variants of our problem. The algorithm achieves almost tight competitive ratios independent of the length of the input sequence.}}, author = {{Feldkord, Björn and Meyer auf der Heide, Friedhelm}}, booktitle = {{Proceedings of the 29th ACM Symposium on Parallelism in Algorithms and Architectures (SPAA)}}, pages = {{313--319}}, title = {{{The Mobile Server Problem}}}, doi = {{10.1145/3087556.3087575}}, year = {{2017}}, } @inproceedings{56, author = {{John, Thomas}}, booktitle = {{1st Business Model Conference}}, location = {{Venice, Italy}}, title = {{{Supporting Business Model Idea Generation Through Machine-generated Ideas: A Design Theory}}}, year = {{2017}}, } @inproceedings{65, abstract = {{Heterogeneous compute nodes in form of CPUs with attached GPU and FPGA accelerators have strongly gained interested in the last years. Applications differ in their execution characteristics and can therefore benefit from such heterogeneous resources in terms of performance or energy consumption. While performance optimization has been the only goal for a long time, nowadays research is more and more focusing on techniques to minimize energy consumption due to rising electricity costs.This paper presents reMinMin, a novel static list scheduling approach for optimizing the total energy consumption for a set of tasks executed on a heterogeneous compute node. reMinMin bases on a new energy model that differentiates between static and dynamic energy components and covers effects of accelerator tasks on the host CPU. The required energy values are retrieved by measurements on the real computing system. In order to evaluate reMinMin, we compare it with two reference implementations on three task sets with different degrees of heterogeneity. In our experiments, MinMin is consistently better than a scheduler optimizing for dynamic energy only, which requires up to 19.43% more energy, and very close to optimal schedules.}}, author = {{Lösch, Achim and Platzner, Marco}}, booktitle = {{Proceedings of the 28th Annual IEEE International Conference on Application-specific Systems, Architectures and Processors (ASAP)}}, title = {{{reMinMin: A Novel Static Energy-Centric List Scheduling Approach Based on Real Measurements}}}, doi = {{10.1109/ASAP.2017.7995272}}, year = {{2017}}, } @inproceedings{66, abstract = {{In budget games, players compete over resources with finite budgets. For every resource, a player has a specific demand and as a strategy, he chooses a subset of resources. If the total demand on a resource does not exceed its budget, the utility of each player who chose that resource equals his demand. Otherwise, the budget is shared proportionally. In the general case, pure Nash equilibria (NE) do not exist for such games. In this paper, we consider the natural classes of singleton and matroid budget games with additional constraints and show that for each, pure NE can be guaranteed. In addition, we introduce a lexicographical potential function to prove that every matroid budget game has an approximate pure NE which depends on the largest ratio between the different demands of each individual player.}}, author = {{Drees, Maximilian and Feldotto, Matthias and Riechers, Sören and Skopalik, Alexander}}, booktitle = {{Proceedings of the 23rd International Computing and Combinatorics Conference (COCOON)}}, pages = {{175----187}}, title = {{{Pure Nash Equilibria in Restricted Budget Games}}}, doi = {{10.1007/978-3-319-62389-4_15}}, year = {{2017}}, } @misc{67, author = {{Jürgens, Mirko}}, publisher = {{Universität Paderborn}}, title = {{{Provably Secure Key-Derivation-Functions for Certain Types of Applications}}}, year = {{2017}}, } @article{68, abstract = {{Proof-carrying hardware (PCH) is a principle for achieving safety for dynamically reconfigurable hardware systems. The producer of a hardware module spends huge effort when creating a proof for a safety policy. The proof is then transferred as a certificate together with the configuration bitstream to the consumer of the hardware module, who can quickly verify the given proof. Previous work utilized SAT solvers and resolution traces to set up a PCH technology and corresponding tool flows. In this article, we present a novel technology for PCH based on inductive invariants. For sequential circuits, our approach is fundamentally stronger than the previous SAT-based one since we avoid the limitations of bounded unrolling. We contrast our technology to existing ones and show that it fits into previously proposed tool flows. We conduct experiments with four categories of benchmark circuits and report consumer and producer runtime and peak memory consumption, as well as the size of the certificates and the distribution of the workload between producer and consumer. Experiments clearly show that our new induction-based technology is superior for sequential circuits, whereas the previous SAT-based technology is the better choice for combinational circuits.}}, author = {{Isenberg, Tobias and Platzner, Marco and Wehrheim, Heike and Wiersema, Tobias}}, journal = {{ACM Transactions on Design Automation of Electronic Systems}}, number = {{4}}, pages = {{61:1----61:23}}, publisher = {{ACM}}, title = {{{Proof-Carrying Hardware via Inductive Invariants}}}, doi = {{10.1145/3054743}}, year = {{2017}}, } @phdthesis{685, author = {{Jakobs, Marie-Christine}}, publisher = {{Universität Paderborn}}, title = {{{On-The-Fly Safety Checking - Customizing Program Certification and Program Restructuring}}}, doi = {{10.17619/UNIPB/1-104}}, year = {{2017}}, } @article{69, abstract = {{Today, software is traded worldwide on global markets, with apps being downloaded to smartphones within minutes or seconds. This poses, more than ever, the challenge of ensuring safety of software in the face of (1) unknown or untrusted software providers together with (2) resource-limited software consumers. The concept of Proof-Carrying Code (PCC), years ago suggested by Necula, provides one framework for securing the execution of untrusted code. PCC techniques attach safety proofs, constructed by software producers, to code. Based on the assumption that checking proofs is usually much simpler than constructing proofs, software consumers should thus be able to quickly check the safety of software. However, PCC techniques often suffer from the size of certificates (i.e., the attached proofs), making PCC techniques inefficient in practice.In this article, we introduce a new framework for the safe execution of untrusted code called Programs from Proofs (PfP). The basic assumption underlying the PfP technique is the fact that the structure of programs significantly influences the complexity of checking a specific safety property. Instead of attaching proofs to program code, the PfP technique transforms the program into an efficiently checkable form, thus guaranteeing quick safety checks for software consumers. For this transformation, the technique also uses a producer-side automatic proof of safety. More specifically, safety proving for the software producer proceeds via the construction of an abstract reachability graph (ARG) unfolding the control-flow automaton (CFA) up to the degree necessary for simple checking. To this end, we combine different sorts of software analysis: expensive analyses incrementally determining the degree of unfolding, and cheap analyses responsible for safety checking. Out of the abstract reachability graph we generate the new program. In its CFA structure, it is isomorphic to the graph and hence another, this time consumer-side, cheap analysis can quickly determine its safety.Like PCC, Programs from Proofs is a general framework instantiable with different sorts of (expensive and cheap) analysis. Here, we present the general framework and exemplify it by some concrete examples. We have implemented different instantiations on top of the configurable program analysis tool CPAchecker and report on experiments, in particular on comparisons with PCC techniques.}}, author = {{Jakobs, Marie-Christine and Wehrheim, Heike}}, journal = {{ACM Transactions on Programming Languages and Systems}}, number = {{2}}, pages = {{7:1--7:56}}, publisher = {{ACM}}, title = {{{Programs from Proofs: A Framework for the Safe Execution of Untrusted Software}}}, doi = {{10.1145/3014427}}, year = {{2017}}, } @misc{696, author = {{Wachowiak, Lennart}}, publisher = {{Universität Paderborn}}, title = {{{Das Mobile Server Problem in Netzwerken}}}, year = {{2017}}, } @misc{697, author = {{Burkhardt, Michel}}, publisher = {{Universität Paderborn}}, title = {{{Untersuchungen zum Cone-Hashing}}}, year = {{2017}}, } @misc{104, author = {{Diemert, Denis}}, publisher = {{Universität Paderborn}}, title = {{{EAX - An Authenticated Encryption Mode for Block Ciphers}}}, year = {{2017}}, } @misc{1048, author = {{Schenk, Andreas}}, publisher = {{Universität Paderborn}}, title = {{{Monotone Suchbarkeit in mehrdimensionalen verteilten Datenstrukturen}}}, year = {{2017}}, } @misc{1049, author = {{Beckendorfer, Björn}}, publisher = {{Universität Paderborn}}, title = {{{Visualisierung zu Algorithmen verteilter Netzwerksysteme}}}, year = {{2017}}, } @inproceedings{105, abstract = {{We initiate the study of network monitoring algorithms in a class of hybrid networks in which the nodes are connected by an external network and an internal network (as a short form for externally and internally controlled network). While the external network lies outside of the control of the nodes (or in our case, the monitoring protocol running in them) and might be exposed to continuous changes, the internal network is fully under the control of the nodes. As an example, consider a group of users with mobile devices having access to the cell phone infrastructure. While the network formed by the WiFi connections of the devices is an external network (as its structure is not necessarily under the control of the monitoring protocol), the connections between the devices via the cell phone infrastructure represent an internal network (as it can be controlled by the monitoring protocol). Our goal is to continuously monitor properties of the external network with the help of the internal network. We present scalable distributed algorithms that efficiently monitor the number of edges, the average node degree, the clustering coefficient, the bipartiteness, and the weight of a minimum spanning tree. Their performance bounds demonstrate that monitoring the external network state with the help of an internal network can be done much more efficiently than just using the external network, as is usually done in the literature.}}, author = {{Gmyr, Robert and Hinnenthal, Kristian and Scheideler, Christian and Sohler, Christian}}, booktitle = {{Proceedings of the 44th International Colloquium on Automata, Languages, and Programming (ICALP)}}, pages = {{137:1----137:15}}, title = {{{Distributed Monitoring of Network Properties: The Power of Hybrid Networks}}}, doi = {{10.4230/LIPIcs.ICALP.2017.137}}, year = {{2017}}, }