@inproceedings{6303, author = {{Senft, Björn and Fischer, Holger Gerhard and Sudbrock, Christian}}, booktitle = {{Mensch & Computer 2014 - Workshopband}}, pages = {{111--116}}, publisher = {{De Gruyter Oldenbourg}}, title = {{{IT-Unterstützung im praktischen Ausbildungsbetrieb der Feuerwehr}}}, year = {{2014}}, } @book{6428, abstract = {{The intensive use of networked embedded systems is one of the key success factors in the automotive industry also triggering a massive shortening of innovation cycles. Hundreds of so called Electronic Control Units (ECUs), connected by kilometers of electrical wiring, operate in today's modern car enabling a huge variety of new functionalities ranging from safety to comfort applications. All this functionality can only be realized if the ECUs are able to communicate and to cooperate using a real-time enabled communication network in the car. Today we are at the verge of another leap forward: This in-car network is being ex- tended to not only connect local ECUs but to connect the whole car to other cars and its environment using Inter-Vehicle Communications (IVCs). Relying on existing wireless Internet access using cellular networks of the third (3G) or fourth generation (4G), or novel networking technologies that are being designed specifically for the use in the vehicular context such as IEEE WAVE, ETSI ITS-G5, and the IEEE 802.11p protocol, it becomes possible to use spontaneous connections between vehicles to exchange information, promising to enable novel and sometimes futuristic applications. Using such IVC, safety relevant information can be exchanged that could not have been obtained using local sensors, enabling a driver to virtually see traffic through large trucks or buildings. This new idea of networked vehicles creates opportunities to not only increase road traffic safety but also to improve our driving experience. Traffic jams can be prevented altogether (or at least we would be informed of jams well in advance) - and we might even be able to enable the driver to enjoying fully automated rides in a train-like convoy of cooperating of vehicles on the road. Vehicular networking, the fusion of vehicles' networks to exchange information, is the common basis on which all of these visions build upon. Being fascinated with all the opportunities and challenges related to vehicular networking, we have been a part of this research community for close to ten years. In this time, many new and sometimes crazy ideas have been formulated how to connect cars of the future. Many of these ideas have been found not suitable after thorough investigation - yet, several survived and paved the road for what are now close to market-ready solutions. From a research perspective, we are able to identify many open challenges, both in the in-car and inter-vehicle communication systems. To investigate these further, we co-organized two Dagstuhl seminars inviting leading experts from all over the world and bringing together practitioners from industry and scientists from research institutes and universities. In this scope, we were able to formulate directions guiding the ongoing research activities at least in the medium term. We also established a complementary seminar series for newcomers to the field, which is being organized in the context of the international FG-IVC series of seminars and organized by the German computer science and electrical engineering societies GI and ITG. This textbook is based on a tutorial series on the same topic presented at all the major IEEE conferences including IEEE CCNC, IEEE ICC, IEEE GLOBECOM, and IEEE VTC, as well as in the scope of Falko Dressler's IEEE Distinguished Lecturer Tours in Europe, the U.S., South America, and Asia-Pacific. We also designed a new graduate level university class, which is being held at different universities in Europe. This has inspired us to collect our experiences in the form of a textbook, collecting in one place the common concepts of past and future vehicular networking topics for a broad range of readers - from students that want to enter this exciting new field to practitioners looking for a comprehensive overview. This book would not have been possible without the many people that have inspired and supported us over the last decade in our research activites on vehicular networking - first and foremost the community centering around the IEEE Vehicular Networking Conference, the premier conference in the field. In particular we'd like to name Prof. Ozan K. Tonguz (CMU) and Prof. Mario Gerla (UCLA) who collaborated with us investigating some of the mentioned crazy ideas, and finally identifying valuable and lasting solutions. The aforementioned tutorial lectues have been prepared together with Dr. Onur Altintas (Toyota ITC) and Prof. Claudio Casetti (Politechnico di Torino). We also wish to express our appreciation for the support we received from the most helpful staff at Cambridge during the preparation of this book. Finally, we would like to sincerely thank our families, friends, and colleagues for their enduring help and support. We hope you will enjoy reading this textbook as much as we enjoyed preparing its contents for you. We gladly welcome any feedback and invite you to leave us a note or peruse supplementary material we are offering on this book's companion website http://book.car2x.org/. }}, author = {{Sommer, Christoph and Dressler, Falko}}, isbn = {{978-1-107-04671-9}}, publisher = {{Cambridge University Press}}, title = {{{Vehicular Networking}}}, doi = {{10.1017/CBO9781107110649}}, year = {{2014}}, } @unpublished{442, abstract = {{We present a new transformation of chosen-plaintext secure predicate encryption schemes with public index into chosen-ciphertext secure schemes. Our construction requires only a universal one-way hash function and is selectively secure in the standard model. The transformation is not generic but can be applied to various existing schemes constructed from bilinear groups. Using common structural properties of these schemes we provide an efficient and simple transformation without overhead in form of one-time signatures or message authentication codes as required in the known generic transformations.}}, author = {{Blömer, Johannes and Liske, Gennadij}}, publisher = {{Universität Paderborn}}, title = {{{Constructing CCA-secure predicate encapsulation schemes from CPA-secure schemes and universal one-way hash functions}}}, year = {{2014}}, } @inproceedings{446, abstract = {{This paper considers the problem of how to efficiently share a wireless medium which is subject to harsh external interference or even jamming. While this problem has already been studied intensively for simplistic single-hop or unit disk graph models, we make a leap forward and study MAC protocols for the SINR interference model (a.k.a. the physical model). We make two contributions. First, we introduce a new adversarial SINR model which captures a wide range of interference phenomena. Concretely, we consider a powerful, adaptive adversary which can jam nodes at arbitrary times and which is only limited by some energy budget. The second contribution of this paper is a distributed MAC protocol which provably achieves a constant competitive throughput in this environment: we show that, with high probability, the protocol ensures that a constant fraction of the non-blocked time periods is used for successful transmissions.}}, author = {{Ogierman, Adrian and Richa, Andrea W. and Scheideler, Christian and Schmid, Stefan and Zhang, Jin}}, booktitle = {{Proceedings of the 33rd Annual IEEE International Conference on Computer Communications (INFOCOM)}}, pages = {{2751----2759}}, title = {{{Competitive MAC under adversarial SINR}}}, doi = {{10.1109/INFOCOM.2014.6848224}}, year = {{2014}}, } @inproceedings{447, abstract = {{Automatic service composition is still a challengingtask. It is even more challenging when dealing witha dynamic market of services for end users. New servicesmay enter the market while other services are completelyremoved. Furthermore, end users are typically no experts in thedomain in which they formulate a request. As a consequence,ambiguous user requests will inevitably emerge and have tobe taken into account. To meet these challenges, we proposea new approach that combines automatic service compositionwith adaptive service recommendation. A best first backwardsearch algorithm produces solutions that are functional correctwith respect to user requests. An adaptive recommendationsystem supports the search algorithm in decision-making.Reinforcement Learning techniques enable the system to adjustits recommendation strategy over time based on user ratings.The integrated approach is described on a conceptional leveland demonstrated by means of an illustrative example fromthe image processing domain.}}, author = {{Jungmann, Alexander and Mohr, Felix and Kleinjohann, Bernd}}, booktitle = {{Proceedings of the 10th World Congress on Services (SERVICES)}}, pages = {{346--353}}, title = {{{Combining Automatic Service Composition with Adaptive Service Recommendation for Dynamic Markets of Services}}}, doi = {{10.1109/SERVICES.2014.68}}, year = {{2014}}, } @inproceedings{449, abstract = {{Cloud computing resulted in a continuously growing number of provided software services to be used by consumers. Brokers discover services that fit best to consumers' requirements by matching Qualityof-Service (QoS) properties. In order to negotiate Service-Level Agreements (SLAs), a provider has to determine the provided QoS based on QoS analyses. However, the risk for the provider to violate the SLA is high as the service's actual quality can deviate from the specified QoS due to uncertainties that occur during the provider's quality analysis. In this paper, we discuss current software engineering paradigms like cloud computing and service-oriented computing with respect to the amount of uncertainty they induce into service matching and SLA negotiations. As a result, we explain, why cloud computing reduces such uncertainties.}}, author = {{Becker, Matthias and Platenius, Marie Christin and Becker, Steffen}}, booktitle = {{Proceedings of the 2nd International Workshop on Cloud Service Brokerage (CSB)}}, pages = {{153--159}}, title = {{{Cloud Computing Reduces Uncertainties in Quality-of-Service Matching!}}}, doi = {{10.1007/978-3-319-14886-1_15}}, year = {{2014}}, } @inproceedings{450, abstract = {{Configurable program analysis (CPA) is a generic concept for the formalization of different software analysis techniques in a single framework. With the tool CPAchecker, this framework allows for an easy configuration and subsequent automatic execution of analysis procedures ranging from data-flow analysis to model checking. The focus of the tool CPAchecker is thus on analysis. In this paper, we study configurability from the point of view of software certification. Certification aims at providing (via a prior analysis) a certificate of correctness for a program which is (a) tamper-proof and (b) more efficient to check for validity than a full analysis. Here, we will show how, given an analysis instance of a CPA, to construct a corresponding sound certification instance, thereby arriving at configurable program certification. We report on experiments with certification based on different analysis techniques, and in particular explain which characteristics of an underlying analysis allow us to design an efficient (in the above (b) sense) certification procedure. }}, author = {{Jakobs, Marie-Christine and Wehrheim, Heike}}, booktitle = {{Proceedings of the 21st International Symposium on Model Checking of Software (SPIN)}}, pages = {{30--39}}, title = {{{Certification for Configurable Program Analysis}}}, doi = {{10.1145/2632362.2632372}}, year = {{2014}}, } @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}}, }