@inproceedings{451, abstract = {{We introduce the concept of budget games. Players choose a set of tasks and each task has a certain demand on every resource in the game. Each resource has a budget. If the budget is not enough to satisfy the sum of all demands, it has to be shared between the tasks. We study strategic budget games, where the budget is shared proportionally. We also consider a variant in which the order of the strategic decisions influences the distribution of the budgets. The complexity of the optimal solution as well as existence, complexity and quality of equilibria are analysed. Finally, we show that the time an ordered budget game needs to convergence towards an equilibrium may be exponential.}}, author = {{Drees, Maximilian and Riechers, Sören and Skopalik, Alexander}}, booktitle = {{Proceedings of the 7th International Symposium on Algorithmic Game Theory (SAGT)}}, editor = {{Lavi, Ron}}, pages = {{110--121}}, title = {{{Budget-restricted utility games with ordered strategic decisions}}}, doi = {{10.1007/978-3-662-44803-8_10}}, year = {{2014}}, } @inproceedings{452, abstract = {{Today's networks, like the Internet, do not consist of one but a mixture of several interconnected networks. Each has individual qualities and hence the performance of a network node results from the networks' interplay.We introduce a new game theoretic model capturing the interplay between a high-speed backbone network and a low-speed general purpose network. In our model, n nodes are connected by a static network and each node can decide individually to become a gateway node. A gateway node pays a fixed price for its connection to the high-speed network, but can utilize the high-speed network to gain communication distance 0 to all other gateways. Communication distances in the low-speed network are given by the hop distances. The effective communication distance between any two nodes then is given by the shortest path, which is possibly improved by using gateways as shortcuts.Every node v has the objective to minimize its communication costs, given by the sum (SUM-game) or maximum (MAX-game) of the effective communication distances from v to all other nodes plus a fixed price \alpha > 0, if it decides to be a gateway. For both games and different ranges of \alpha, we study the existence of equilibria, the price of anarchy, and convergence properties of best-response dynamics.}}, author = {{Abshoff, Sebastian and Cord-Landwehr, Andreas and Jung, Daniel and Skopalik, Alexander}}, booktitle = {{Proceedings of the 7th International Symposium on Algorithmic Game Theory (SAGT)}}, editor = {{Lavi, Ron}}, pages = {{294}}, title = {{{Brief Announcement: A Model for Multilevel Network Games}}}, year = {{2014}}, } @inproceedings{453, abstract = {{In this paper we study the potential function in congestion games. We consider both games with non-decreasing cost functions as well as games with non-increasing utility functions. We show that the value of the potential function $\Phi(\sf s)$ of any outcome $\sf s$ of a congestion game approximates the optimum potential value $\Phi(\sf s^*)$ by a factor $\Psi_{\mathcal{F}}$ which only depends on the set of cost/utility functions $\mathcal{F}$, and an additive term which is bounded by the sum of the total possible improvements of the players in the outcome $\sf s$. The significance of this result is twofold. On the one hand it provides \emph{Price-of-Anarchy}-like results with respect to the potential function. On the other hand, we show that these approximations can be used to compute $(1+\varepsilon)\cdot\Psi_{\mathcal{F}}$-approximate pure Nash equilibria for congestion games with non-decreasing cost functions. For the special case of polynomial cost functions, this significantly improves the guarantees from Caragiannis et al. [FOCS 2011]. Moreover, our machinery provides the first guarantees for general latency functions.}}, author = {{Feldotto, Matthias and Gairing, Martin and Skopalik, Alexander}}, booktitle = {{Proceedings of the 10th International Conference on Web and Internet Economics (WINE)}}, pages = {{30--43}}, title = {{{Bounding the Potential Function in Congestion Games and Approximate Pure Nash Equilibria}}}, doi = {{10.1007/978-3-319-13129-0_3}}, year = {{2014}}, } @inproceedings{455, abstract = {{We study the existence of approximate pure Nash equilibria in weighted congestion games and develop techniques to obtain approximate potential functions that prove the existence of alpha-approximate pure Nash equilibria and the convergence of alpha-improvement steps. Specifically, we show how to obtain upper bounds for approximation factor alpha for a given class of cost functions. For example for concave cost functions the factor is at most 3/2, for quadratic cost functions it is at most 4/3, and for polynomial cost functions of maximal degree d it is at at most d + 1. For games with two players we obtain tight bounds which are as small as for example 1.054 in the case of quadratic cost functions.}}, author = {{Hansknecht, Christoph and Klimm, Max and Skopalik, Alexander}}, booktitle = {{Proceedings of the 17th. International Workshop on Approximation Algorithms for Combinatorial Optimization Problems (APPROX)}}, pages = {{242 -- 257}}, title = {{{Approximate pure Nash equilibria in weighted congestion games}}}, doi = {{10.4230/LIPIcs.APPROX-RANDOM.2014.242}}, year = {{2014}}, } @inproceedings{456, abstract = {{We study the existence of approximate pure Nash equilibriain social context congestion games. For any given set of allowed costfunctions F, we provide a threshold value μ(F), and show that for theclass of social context congestion games with cost functions from F, α-Nash dynamics are guaranteed to converge to α-approximate pure Nashequilibrium if and only if α > μ(F).Interestingly, μ(F) is related and always upper bounded by Roughgarden’sanarchy value [19].}}, author = {{Gairing, Martin and Kotsialou, Grammateia and Skopalik, Alexander}}, booktitle = {{Proceedings of the 10th International Conference on Web and Internet Economics (WINE)}}, pages = {{480 -- 485}}, title = {{{Approximate pure Nash equilibria in Social Context Congestion Games}}}, doi = {{10.1007/978-3-319-13129-0_43}}, year = {{2014}}, } @inproceedings{457, abstract = {{Automatically composing service-based software solutionsis still a challenging task. Functional as well as nonfunctionalproperties have to be considered in order to satisfyindividual user requests. Regarding non-functional properties,the composition process can be modeled as optimization problemand solved accordingly. Functional properties, in turn, can bedescribed by means of a formal specification language. Statespacebased planning approaches can then be applied to solvethe underlying composition problem. However, depending on theexpressiveness of the applied formalism and the completenessof the functional descriptions, formally equivalent services maystill differ with respect to their implemented functionality. As aconsequence, the most appropriate solution for a desired functionalitycan hardly be determined without considering additionalinformation. In this paper, we demonstrate how to overcome thislack of information by means of Reinforcement Learning. Inorder to resolve ambiguity, we expand state-space based servicecomposition by a recommendation mechanism that supportsdecision-making beyond formal specifications. The recommendationmechanism adjusts its recommendation strategy basedon feedback from previous composition runs. Image processingserves as case study. Experimental results show the benefit of ourproposed solution.}}, author = {{Jungmann, Alexander and Mohr, Felix and Kleinjohann, Bernd }}, booktitle = {{Proceedings of the 7th International Conference on Service Oriented Computing and Applications (SOCA)}}, pages = {{105--112}}, title = {{{Applying Reinforcement Learning for Resolving Ambiguity in Service Composition}}}, doi = {{10.1109/SOCA.2014.48}}, year = {{2014}}, } @misc{458, author = {{Dreimann, Philipp}}, publisher = {{Universität Paderborn}}, title = {{{Anticipatory Power Cycling of Mobile Network Equipment for High-Demand Multimedia Traffic}}}, year = {{2014}}, } @inproceedings{459, abstract = {{In this survey article, we discuss two algorithmic research areas that emerge from problems that arise when resources are offered in the cloud. The first area, online leasing, captures problems arising from the fact that resources in the cloud are not bought, but leased by cloud vendors. The second area, Distributed Storage Systems, deals with problems arising from so-called cloud federations, i.e., when several cloud providers are needed to fulfill a given task.}}, author = {{Kniesburges, Sebastian and Markarian, Christine and Meyer auf der Heide, Friedhelm and Scheideler, Christian}}, booktitle = {{Proceedings of the 21st International Colloquium on Structural Information and Communication Complexity (SIROCCO)}}, pages = {{1--13}}, title = {{{Algorithmic Aspects of Resource Management in the Cloud}}}, doi = {{10.1007/978-3-319-09620-9_1}}, year = {{2014}}, } @misc{461, author = {{Dräxler, Sevil}}, publisher = {{Universität Paderborn}}, title = {{{Adaptive Placement of Programmable Virtual Network Function Chains}}}, year = {{2014}}, } @inproceedings{462, abstract = {{We discuss a technique to analyze complex infinitely repeated games using techniques from the fields of game theory and simulations. Our research is motivated by the analysis of electronic markets with thousands of participants and possibly complex strategic behavior. We consider an example of a global market of composed IT services to demonstrate the use of our simulation technique. We present our current work in this area and we want to discuss further approaches for the future.}}, author = {{Feldotto, Matthias and Skopalik, Alexander}}, booktitle = {{Proceedings of the 4th International Conference on Simulation and Modeling Methodologies, Technologies and Applications (SIMULTECH 2014)}}, pages = {{625--630}}, title = {{{A Simulation Framework for Analyzing Complex Infinitely Repeated Games}}}, doi = {{10.5220/0005110406250630}}, year = {{2014}}, } @inproceedings{463, abstract = {{Several fault attacks against pairing-based cryptography have been described theoretically in recent years. Interestingly, none of these have been practically evaluated. We accomplished this task and prove that fault attacks against pairing-based cryptography are indeed possible and are even practical — thus posing a serious threat. Moreover, we successfully conducted a second-order fault attack against an open source implementation of the eta pairing on an AVR XMEGA A1. We injected the first fault into the computation of the Miller Algorithm and applied the second fault to skip the final exponentiation completely. We introduce a low-cost setup that allowed us to generate multiple independent faults in one computation. The setup implements these faults by clock glitches which induce instruction skips. With this setup we conducted the first practical fault attack against a complete pairing computation.}}, author = {{Blömer, Johannes and Gomes da Silva, Ricardo and Günther, Peter and Krämer, Juliane and Seifert, Jean-Pierre}}, booktitle = {{Proceedings of Fault Tolerance and Diagnosis in Cryptography(FDTC)}}, pages = {{123----136}}, title = {{{A Practical Second-Order Fault Attack against a Real-World Pairing Implementation}}}, doi = {{10.1109/FDTC.2014.22}}, year = {{2014}}, } @article{464, abstract = {{Topological self-stabilization is an important concept to build robust open distributed systems (such as peer-to-peer systems) where nodes can organize themselves into meaningful network topologies. The goal is to devise distributed algorithms where nodes forward, insert, and delete links to neighboring nodes, and that converge quickly to such a desirable topology, independently of the initial network configuration. This article proposes a new model to study the parallel convergence time. Our model sheds light on the achievable parallelism by avoiding bottlenecks of existing models that can yield a distorted picture. As a case study, we consider local graph linearization—i.e., how to build a sorted list of the nodes of a connected graph in a distributed and self-stabilizing manner. In order to study the main structure and properties of our model, we propose two variants of a most simple local linearization algorithm. For each of these variants, we present analyses of the worst-case and bestcase parallel time complexities, as well as the performance under a greedy selection of the actions to be executed. It turns out that the analysis is non-trivial despite the simple setting, and to complement our formal insights we report on our experiments which indicate that the runtimes may be better in the average case.}}, author = {{Gall, Dominik and Jacob, Riko and Richa, Andrea W. and Scheideler, Christian and Schmid, Stefan and Täubig, Hanjo }}, journal = {{Theory of Computing Systems}}, number = {{1}}, pages = {{110--135}}, publisher = {{Springer}}, title = {{{A Note on the Parallel Runtime of Self-Stabilizing Graph Linearization}}}, doi = {{10.1007/s00224-013-9504-x}}, year = {{2014}}, } @article{467, abstract = {{Financial benefits are an important factor when cloud infrastructure is considered to meet processing demand. The dynamics of on-demand pricing and service usage are investigated in a two-stage game model for a monopoly Infrastructure-as-a-Service (IaaS) market. The possibility of hybrid clouds (public clouds plus own infrastructure) turns out to be essential in order that not only the provider but also the clients have significant benefits from on-demand services. Even if the client meets all demand in the public cloud, the threat of building a hybrid cloud keeps the instance price low. This is not the case when reserved instances are offered as well. Parameters like load profiles and economies of scale have a huge effect on likely future pricing and on a cost-optimal split-up of client demand between either a client’s own data center and a public cloud service or between reserved and on-demand cloud instances.}}, author = {{Künsemöller, Jörn and Karl, Holger}}, journal = {{Future Generation Computer Systems}}, pages = {{44----52}}, publisher = {{Elsevier}}, title = {{{A Game-Theoretic Approach to the Financial Benefits of Infrastructure-as-a-Service}}}, doi = {{10.1016/j.future.2014.03.005}}, year = {{2014}}, } @article{7268, author = {{Klenke, Markus and Grieger, Marvin}}, journal = {{DOAG News}}, number = {{3}}, pages = {{38--42}}, title = {{{Forms2ADF mal anders: Wie aus einer Oracle-Vision Praxis wird}}}, year = {{2014}}, } @article{7269, author = {{Grieger, Marvin and Fazal-Baqaie, Masud and Sauer, Stefan and Klenke, Markus}}, journal = {{Softwaretechnik-Trends, Proceedings of the 16th Workshop Software-Reengineering (WSRE)}}, number = {{2}}, pages = {{77--78}}, title = {{{A Method to Systematically Improve the Effectiveness and Efficiency of the Semi-Automatic Migration of Legacy Systems}}}, volume = {{34}}, year = {{2014}}, } @article{7270, author = {{Grieger, Marvin and Sauer, Stefan and Klenke, Markus}}, journal = {{Softwaretechnik-Trends, Proceedings of the 2nd Workshop Model-Based and Model-Driven Software Modernization (MMSM)}}, number = {{2}}, pages = {{44--45}}, title = {{{Architectural Restructuring by Semi-Automatic Clustering to Facilitate Migration towards a Service-oriented Architecture}}}, volume = {{34}}, year = {{2014}}, } @article{753, author = {{Beister, Frederic and Dräxler, Martin and Aelken, J. and Karl, Holger}}, journal = {{Computer Communications}}, pages = {{77----85}}, title = {{{Power model design for ICT systems -- A generic approach}}}, doi = {{10.1016/j.comcom.2014.02.007}}, year = {{2014}}, } @article{754, author = {{Azeem M. Khan, Rana and Karl, Holger}}, journal = {{IEEE Communications Surveys and Tutorials}}, number = {{1}}, pages = {{46----63}}, title = {{{MAC Protocols for Cooperative Diversity in Wireless LANs and Wireless Sensor Networks}}}, doi = {{10.1109/SURV.2013.042313.00067}}, year = {{2014}}, } @inproceedings{759, author = {{Dräxler, Martin and Dreimann, Philipp and Karl, Holger}}, booktitle = {{IEEE Online Conference on Green Communications, OnlineGreenComm 2014, November 12-14, 2014}}, pages = {{1----7}}, title = {{{Anticipatory power cycling of mobile network equipment for high demand multimedia traffic}}}, doi = {{10.1109/OnlineGreenCom.2014.7114415}}, year = {{2014}}, } @inproceedings{760, author = {{Auroux, Sebastien and Karl, Holger}}, booktitle = {{25th IEEE Annual International Symposium on Personal, Indoor, and Mobile Radio Communication, {PIMRC} 2014, Washington DC, USA, September 2-5, 2014}}, pages = {{1294----1299}}, title = {{{Flow processing-aware controller placement in wireless DenseNets}}}, doi = {{10.1109/PIMRC.2014.7136368}}, year = {{2014}}, }