@article{3307, author = {{Frick, Bernd and Kaimann, Daniel}}, journal = {{Applied Economics Letters}}, number = {{17}}, pages = {{1237--1240}}, publisher = {{Taylor & Francis}}, title = {{{The impact of customer reviews and advertisement efforts on the performance of experience goods in electronic markets}}}, doi = {{10.1080/13504851.2016.1270399}}, volume = {{24}}, year = {{2017}}, } @misc{3312, author = {{Zarindast, Mana}}, publisher = {{Universität Paderborn}}, title = {{{The role of eWOM in the movie industry: The effect of online user ratings on box office sales }}}, year = {{2017}}, } @inproceedings{3325, author = {{Melnikov, Vitalik and Hüllermeier, Eyke}}, booktitle = {{Proceedings. 27. Workshop Computational Intelligence, Dortmund, 23. - 24. November 2017}}, publisher = {{KIT Scientific Publishing}}, title = {{{Optimizing the Structure of Nested Dichotomies: A Comparison of Two Heuristics}}}, doi = {{10.5445/KSP/1000074341}}, year = {{2017}}, } @misc{3512, author = {{Börding, Paul}}, publisher = {{Universität Paderborn}}, title = {{{Testing Java Method Contracts}}}, year = {{2017}}, } @misc{3580, author = {{Hansmeier, Tim}}, publisher = {{Universität Paderborn}}, title = {{{An FPGA Accelerator for Checking Resolution Proofs}}}, year = {{2017}}, } @inproceedings{2967, author = {{Blömer, Johannes and Liske, Gennadij}}, booktitle = {{Proceedings of the International Conference of Mathematical Aspects of Computer and Information Sciences (MACIS)}}, isbn = {{9783319724522}}, issn = {{0302-9743}}, pages = {{438--453}}, publisher = {{Springer International Publishing}}, title = {{{Subtleties in Security Definitions for Predicate Encryption with Public Index}}}, doi = {{10.1007/978-3-319-72453-9_35}}, volume = {{10693}}, year = {{2017}}, } @inproceedings{112, abstract = {{We study a model of selfish resource allocation that seeks to incorporate dependencies among resources as they exist in in modern networked environments. Our model is inspired by utility functions with constant elasticity of substitution (CES) which is a well-studied model in economics. We consider congestion games with different aggregation functions. In particular, we study $L_p$ norms and analyze the existence and complexity of (approximate) pure Nash equilibria. Additionally, we give an almost tight characterization based on monotonicity properties to describe the set of aggregation functions that guarantee the existence of pure Nash equilibria.}}, author = {{Feldotto, Matthias and Leder, Lennart and Skopalik, Alexander}}, booktitle = {{Proceedings of the 10th International Conference on Algorithms and Complexity (CIAC)}}, pages = {{222----233}}, title = {{{Congestion Games with Complementarities}}}, doi = {{10.1007/978-3-319-57586-5_19}}, year = {{2017}}, } @inproceedings{113, abstract = {{We study the computation of approximate pure Nash equilibria in Shapley value (SV) weighted congestion games, introduced in [19]. This class of games considers weighted congestion games in which Shapley values are used as an alternative (to proportional shares) for distributing the total cost of each resource among its users. We focus on the interesting subclass of such games with polynomial resource cost functions and present an algorithm that computes approximate pure Nash equilibria with a polynomial number of strategy updates. Since computing a single strategy update is hard, we apply sampling techniques which allow us to achieve polynomial running time. The algorithm builds on the algorithmic ideas of [7], however, to the best of our knowledge, this is the first algorithmic result on computation of approximate equilibria using other than proportional shares as player costs in this setting. We present a novel relation that approximates the Shapley value of a player by her proportional share and vice versa. As side results, we upper bound the approximate price of anarchy of such games and significantly improve the best known factor for computing approximate pure Nash equilibria in weighted congestion games of [7].}}, author = {{Feldotto, Matthias and Gairing, Martin and Kotsialou, Grammateia and Skopalik, Alexander}}, booktitle = {{Proceedings of the 13th International Conference on Web and Internet Economics (WINE)}}, title = {{{Computing Approximate Pure Nash Equilibria in Shapley Value Weighted Congestion Games}}}, doi = {{10.1007/978-3-319-71924-5_14}}, year = {{2017}}, } @inproceedings{114, abstract = {{Proof witnesses are proof artifacts showing correctness of programs wrt. safety properties. The recent past has seen a rising interest in witnesses as (a) proofs in a proof-carrying-code context, (b) certificates for the correct functioning of verification tools, or simply (c) exchange formats for (partial) verification results. As witnesses in all theses scenarios need to be stored and processed, witnesses are required to be as small as possible. However, software verification tools – the prime suppliers of witnesses – do not necessarily construct small witnesses. In this paper, we present a formal account of proof witnesses. We introduce the concept of weakenings, reducing the complexity of proof witnesses while preserving the ability of witnessing safety. We develop aweakening technique for a specific class of program analyses, and prove it to be sound. Finally, we experimentally demonstrate our weakening technique to indeed achieve a size reduction of proof witnesses.}}, author = {{Jakobs, Marie-Christine and Wehrheim, Heike}}, booktitle = {{NASA Formal Methods: 9th International Symposium}}, editor = {{Barrett, Clark and Davies, Misty and Kahsai, Temesghen}}, pages = {{389--403}}, title = {{{Compact Proof Witnesses}}}, doi = {{10.1007/978-3-319-57288-8_28}}, year = {{2017}}, } @inproceedings{115, abstract = {{Whenever customers have to decide between different instances of the same product, they are interested in buying the best product. In contrast, companies are interested in reducing the construction effort (and usually as a consequence thereof, the quality) to gain profit. The described setting is widely known as opposed preferences in quality of the product and also applies to the context of service-oriented computing. In general, service-oriented computing emphasizes the construction of large software systems out of existing services, where services are small and self-contained pieces of software that adhere to a specified interface. Several implementations of the same interface are considered as several instances of the same service. Thereby, customers are interested in buying the best service implementation for their service composition wrt. to metrics, such as costs, energy, memory consumption, or execution time. One way to ensure the service quality is to employ certificates, which can come in different kinds: Technical certificates proving correctness can be automatically constructed by the service provider and again be automatically checked by the user. Digital certificates allow proof of the integrity of a product. Other certificates might be rolled out if service providers follow a good software construction principle, which is checked in annual audits. Whereas all of these certificates are handled differently in service markets, what they have in common is that they influence the buying decisions of customers. In this paper, we review state-of-the-art developments in certification with respect to service-oriented computing. We not only discuss how certificates are constructed and handled in service-oriented computing but also review the effects of certificates on the market from an economic perspective.}}, author = {{Jakobs, Marie-Christine and Krämer, Julia and van Straaten, Dirk and Lettmann, Theodor}}, booktitle = {{The Ninth International Conferences on Advanced Service Computing (SERVICE COMPUTATION)}}, editor = {{Marcelo De Barros, Janusz Klink,Tadeus Uhl, Thomas Prinz}}, pages = {{7--12}}, title = {{{Certification Matters for Service Markets}}}, year = {{2017}}, } @misc{1157, author = {{Witschen, Linus Matthias}}, publisher = {{Universität Paderborn}}, title = {{{A Framework for the Synthesis of Approximate Circuits}}}, year = {{2017}}, } @phdthesis{116, author = {{Liske, Gennadij}}, publisher = {{Universität Paderborn}}, title = {{{CCA-Security for Predicate Encryption Schemes}}}, doi = {{10.17619/UNIPB/1-220}}, year = {{2017}}, } @inproceedings{1767, abstract = {{Conditional Value-at-Risk, denoted as CVaRα, is becoming the prevailing measure of risk over two paramount economic domains: the insurance domain and the financial domain; α∈(0,1) is the confidence level. In this work, we study the strategic equilibria for an economic system modeled as a game, where risk-averse players seek to minimize the Conditional Value-at-Risk of their costs. Concretely, in a CVaRα -equilibrium, the mixed strategy of each player is a best-response. We establish two significant properties of CVaRα at equilibrium: (1) The Optimal-Value property: For any best-response of a player, each mixed strategy in the support gives the same cost to the player. This follows directly from the concavity of CVaRα in the involved probabilities, which we establish. (2) The Crawford property: For every α, there is a 2-player game with no CVaRα-equilibrium. The property is established using the Optimal-Value property and a new functional property of CVaRα, called Weak-Equilibrium-for- VaRα, we establish. On top of these properties, we show, as one of our two main results, that deciding the existence of a CVaRα-equilibrium is strongly NP-hard even for 2-player games. As our other main result, we show the strong NP-hardness of deciding the existence of a V-equilibrium, over 2-player games, for any valuation V with the Optimal-Value and the Crawford properties. This result has a rich potential since we prove that the very significant and broad class of strictly quasiconcave valuations has the Optimal-Value property.}}, author = {{Mavronicolas, Marios and Monien, Burkhard}}, booktitle = {{Proceedings of the 10th International Symposium on Algorithmic Game Theory (SAGT 2017)}}, location = {{L'Aquila, Italy}}, pages = {{131----143}}, title = {{{Conditional Value-at-Risk: Structure and Complexity of Equilibria}}}, doi = {{10.1007/978-3-319-66700-3_11}}, volume = {{10504}}, year = {{2017}}, } @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{18026, author = {{Burkhardt, Michél }}, publisher = {{Universität Paderborn}}, title = {{{Untersuchungen zum Cone-Hashing}}}, year = {{2017}}, } @misc{18027, author = {{Banh, Ngoc Chi}}, publisher = {{Universität Paderborn}}, title = {{{An Asynchronous Adaption of a Churn-resistant Overlay Network}}}, year = {{2017}}, } @misc{18028, author = {{Schenk, Andreas}}, publisher = {{Universität Paderborn}}, title = {{{Monotone Suchbarkeit in mehrdimensionalen verteilten Datenstrukturen}}}, year = {{2017}}, } @misc{18029, author = {{Beckendorf, Björn}}, publisher = {{Universität Paderborn}}, title = {{{Visualisierung zu Algorithmen verteilter Netzwerksysteme}}}, year = {{2017}}, } @article{2269, author = {{Mauleon, Ana and Roehl, Nils and Vannetelbosch, Vincent}}, issn = {{0899-8256}}, journal = {{Games and Economic Behavior}}, pages = {{135--152}}, publisher = {{Elsevier}}, title = {{{Constitutions and groups}}}, doi = {{10.1016/j.geb.2017.10.022}}, volume = {{107}}, year = {{2017}}, } @misc{2272, author = {{Golke, Vanessa}}, publisher = {{Universität Paderborn}}, title = {{{Signaling und Screening - Abbau von Informationsasymmetrie}}}, year = {{2017}}, }