@inproceedings{275, abstract = {{We investigate a non-cooperative game-theoretic model for the formation of communication networks by selfish agents. Each agent aims for a central position at minimum cost for creating edges. In particular, the general model (Fabrikant et al., PODC'03) became popular for studying the structure of the Internet or social networks. Despite its significance, locality in this game was first studied only recently (Bilò et al., SPAA'14), where a worst case locality model was presented, which came with a high efficiency loss in terms of quality of equilibria. Our main contribution is a new and more optimistic view on locality: agents are limited in their knowledge and actions to their local view ranges, but can probe different strategies and finally choose the best. We study the influence of our locality notion on the hardness of computing best responses, convergence to equilibria, and quality of equilibria. Moreover, we compare the strength of local versus non-local strategy changes. Our results address the gap between the original model and the worst case locality variant. On the bright side, our efficiency results are in line with observations from the original model, yet we have a non-constant lower bound on the Price of Anarchy.}}, author = {{Cord-Landwehr, Andreas and Lenzner, Pascal}}, booktitle = {{Proceedings of the 40th Conference on Mathematical Foundations of Computer Science (MFCS)}}, pages = {{248----260}}, title = {{{Network Creation Games: Think Global - Act Local}}}, doi = {{10.1007/978-3-662-48054-0_21}}, year = {{2015}}, } @misc{277, author = {{Kothe, Nils}}, publisher = {{Universität Paderborn}}, title = {{{Multilevel Netzwerk Spiele mit konstanten Entfernungen im Highspeed-Netzwerk}}}, year = {{2015}}, } @inproceedings{17425, author = {{Berssenbrügge, Jan and Wiederkehr, Olga and Jähn, Claudius and Fischer, Matthias}}, booktitle = {{12. Paderborner Workshop Augmented & Virtual Reality in der Produktentstehung}}, pages = {{65--78}}, publisher = {{Verlagsschriftenreihe des Heinz Nixdorf Instituts}}, title = {{{Anbindung des Virtuellen Prototypen an die Partialmodelle intelligenter technischer Systeme}}}, volume = {{343}}, year = {{2015}}, } @inproceedings{17427, author = {{Jähn, Claudius and Fischer, Matthias and Gerges, Maria and Berssenbrügge, Jan}}, booktitle = {{12. Paderborner Workshop Augmented & Virtual Reality in der Produktentstehung}}, pages = {{107--120}}, publisher = {{Verlagsschriftenreihe des Heinz Nixdorf Instituts}}, title = {{{Automatische Ableitung geometrischer Eigenschaften von Bauteilen aus dem 3-D-Polygonmodell}}}, volume = {{342}}, year = {{2015}}, } @book{17431, editor = {{Gausemeier, Jürgen and Grafe, Michael and Meyer auf der Heide, Friedhelm}}, publisher = {{Verlagsschriftenreihe des Heinz Nixdorf Instituts}}, title = {{{Augmented & Virtual Reality in der Produktentstehung: Grundlagen, Methoden und Werkzeuge; Interaktions- und Visualisierungstechniken, Virtual Prototyping intelligenter technischer Systeme mit AR/VR}}}, volume = {{342}}, year = {{2015}}, } @article{17657, abstract = {{Inter-datacenter transfers of non-interactive but timely large flows over a private (managed) network is an important problem faced by many cloud service providers. The considered flows are non-interactive because they do not explicitly target the end users. However, most of them must be performed on a timely basis and are associated with a deadline. We propose to schedule these flows by a centralized controller, which determines when to transmit each flow and which path to use. Two scheduling models are presented in this paper. In the first, the controller also determines the rate of each flow, while in the second bandwidth is assigned by the network according to the TCP rules. We develop scheduling algorithms for both models and compare their complexity and performance.}}, author = {{Cohen, R. and Polevoy, Gleb}}, issn = {{2168-7161}}, journal = {{Cloud Computing, IEEE Transactions on}}, keywords = {{Approximation algorithms, Approximation methods, Bandwidth, Cloud computing, Routing, Schedules, Scheduling}}, number = {{99}}, pages = {{1--1}}, title = {{{Inter-Datacenter Scheduling of Large Data Flows}}}, doi = {{10.1109/TCC.2015.2487964}}, volume = {{PP}}, year = {{2015}}, } @article{17658, abstract = {{Abstract We study the problem of bandwidth allocation with multiple interferences. In this problem the input consists of a set of users and a set of base stations. Each user has a list of requests, each consisting of a base station, a frequency demand, and a profit that may be gained by scheduling this request. The goal is to find a maximum profit set of user requests S that satisfies the following conditions: (i) S contains at most one request per user, (ii) the frequency sets allotted to requests in S that correspond to the same base station are pairwise non-intersecting, and (iii) the QoS received by any user at any frequency is reasonable according to an interference model. In this paper we consider two variants of bandwidth allocation with multiple interferences. In the first each request specifies a demand that can be satisfied by any subset of frequencies that is large enough. In the second each request specifies a specific frequency interval. Furthermore, we consider two interference models, multiplicative and additive. We show that these problems are extremely hard to approximate if the interferences depend on both the interfered and the interfering base stations. On the other hand, we provide constant factor approximation algorithms for both variants of bandwidth allocation with multiple interferences for the case where the interferences depend only on the interfering base stations. We also consider a restrictive special case that is closely related to the Knapsack problem. We show that this special case is NP-hard and that it admits an FPTAS. }}, author = {{Bar-Yehuda, Reuven and Polevoy, Gleb and Rawitz, Dror}}, issn = {{0166-218X}}, journal = {{Discrete Applied Mathematics }}, keywords = {{Local ratio}}, pages = {{23 -- 36}}, publisher = {{Elsevier}}, title = {{{Bandwidth allocation in cellular networks with multiple interferences}}}, doi = {{http://dx.doi.org/10.1016/j.dam.2015.05.013}}, volume = {{194}}, year = {{2015}}, } @inproceedings{240, abstract = {{We consider online leasing problems in which demands arrive over time and need to be served by leasing resources. We introduce a new model for these problems such that a resource can be leased for K different durations each incurring a different cost (longer leases cost less per time unit). Each demand i can be served anytime between its arrival ai and its deadline ai+di by a leased resource. The objective is to meet all deadlines while minimizing the total leasing costs. This model is a natural generalization of Meyerson’s ParkingPermitProblem (FOCS 2005) in which di=0 for all i. We propose an online algorithm that is Θ(K+dmaxlmin)-competitive where dmax and lmin denote the largest di and the shortest available lease length, respectively. We also extend the SetCoverLeasing problem by deadlines and give a competitive online algorithm which also improves on existing solutions for the original SetCoverLeasing problem.}}, author = {{Li, Shouwei and Mäcker, Alexander and Markarian, Christine and Meyer auf der Heide, Friedhelm and Riechers, Sören}}, booktitle = {{Proceedings of the 21st Annual International Computing and Combinatorics Conference (COCOON)}}, pages = {{277----288}}, title = {{{Towards Flexible Demands in Online Leasing Problems}}}, doi = {{10.1007/978-3-319-21398-9_22}}, year = {{2015}}, } @unpublished{16449, abstract = {{We consider the following variant of the two dimensional gathering problem for swarms of robots: Given a swarm of $n$ indistinguishable, point shaped robots on a two dimensional grid. Initially, the robots form a closed chain on the grid and must keep this connectivity during the whole process of their gathering. Connectivity means, that neighboring robots of the chain need to be positioned at the same or neighboring points of the grid. In our model, gathering means to keep shortening the chain until the robots are located inside a $2\times 2$ subgrid. Our model is completely local (no global control, no global coordinates, no compass, no global communication or vision, \ldots). Each robot can only see its next constant number of left and right neighbors on the chain. This fixed constant is called the \emph{viewing path length}. All its operations and detections are restricted to this constant number of robots. Other robots, even if located at neighboring or the same grid point cannot be detected. Only based on the relative positions of its detectable chain neighbors, a robot can decide to obtain a certain state. Based on this state and their local knowledge, the robots do local modifications to the chain by moving to neighboring grid points without breaking the chain. These modifications are performed without the knowledge whether they lead to a global progress or not. We assume the fully synchronous $\mathcal{FSYNC}$ model. For this problem, we present a gathering algorithm which needs linear time. This result generalizes the result from \cite{hopper}, where an open chain with specified distinguishable (and fixed) endpoints is considered.}}, author = {{Abshoff, Sebastian and Cord-Landwehr, Andreas and Fischer, Matthias and Jung, Daniel and Meyer auf der Heide, Friedhelm}}, booktitle = {{arXiv:1510.05454}}, title = {{{Gathering a Closed Chain of Robots on a Grid}}}, year = {{2015}}, } @unpublished{16452, abstract = {{We consider the problem of dominating set-based virtual backbone used for routing in asymmetric wireless ad-hoc networks. These networks have non-uniform transmission ranges and are modeled using the well-established disk graphs. The corresponding graph theoretic problem seeks a strongly connected dominating-absorbent set of minimum cardinality in a digraph. A subset of nodes in a digraph is a strongly connected dominating-absorbent set if the subgraph induced by these nodes is strongly connected and each node in the graph is either in the set or has both an in-neighbor and an out-neighbor in it. Distributed algorithms for this problem are of practical significance due to the dynamic nature of ad-hoc networks. We present a first distributed approximation algorithm, with a constant approximation factor and O(Diam) running time, where Diam is the diameter of the graph. Moreover we present a simple heuristic algorithm and conduct an extensive simulation study showing that our heuristic outperforms previously known approaches for the problem.}}, author = {{Abu-Khzam, Faisal N. and Markarian, Christine and Meyer auf der Heide, Friedhelm and Schubert, Michael}}, booktitle = {{arXiv:1510.01866}}, title = {{{Approximation and Heuristic Algorithms for Computing Backbones in Asymmetric Ad-Hoc Networks}}}, year = {{2015}}, } @inproceedings{16460, abstract = {{Consider n nodes connected to a single coordinator. Each node receives an individual online data stream of numbers and, at any point in time, the coordinator has to know the k nodes currently observing the largest values, for a given k between 1 and n. We design and analyze an algorithm that solves this problem while bounding the amount of messages exchanged between the nodes and the coordinator. Our algorithm employs the idea of using filters which, intuitively speaking, leads to few messages to be sent, if the new input is "similar" to the previous ones. The algorithm uses a number of messages that is on expectation by a factor of O((log {\Delta} + k) log n) larger than that of an offline algorithm that sets filters in an optimal way, where {\Delta} is upper bounded by the largest value observed by any node.}}, author = {{Mäcker, Alexander and Malatyali, Manuel and Meyer auf der Heide, Friedhelm}}, booktitle = {{Proceedings of the 29th International Parallel and Distributed Processing Symposium (IPDPS)}}, pages = {{357--364}}, publisher = {{IEEE}}, title = {{{Online Top-k-Position Monitoring of Distributed Data Streams}}}, doi = {{10.1109/IPDPS.2015.40}}, year = {{2015}}, } @article{16391, author = {{Degener, Bastian and Kempkes, Barbara and Kling, Peter and Meyer auf der Heide, Friedhelm}}, issn = {{2329-4949}}, journal = {{ACM Transactions on Parallel Computing}}, pages = {{1--18}}, title = {{{Linear and Competitive Strategies for Continuous Robot Formation Problems}}}, doi = {{10.1145/2742341}}, year = {{2015}}, } @unpublished{16397, abstract = {{In the gathering problem, n autonomous robots have to meet on a single point. We consider the gathering of a closed chain of point-shaped, anonymous robots on a grid. The robots only have local knowledge about a constant number of neighboring robots along the chain in both directions. Actions are performed in the fully synchronous time model FSYNC. Every robot has a limited memory that may contain one timestamp of the global clock, also visible to its direct neighbors. In this synchronous time model, there is no limited view gathering algorithm known to perform better than in quadratic runtime. The configurations that show the quadratic lower bound are closed chains. In this paper, we present the first sub-quadratic---in fact linear time---gathering algorithm for closed chains on a grid.}}, author = {{Abshoff, Sebastian and Andreas Cord-Landwehr, Andreas and Jung, Daniel and Meyer auf der Heide, Friedhelm}}, booktitle = {{ArXiv: 1501.04877}}, title = {{{Towards Gathering Robots with Limited View in Linear Time: The Closed Chain Case}}}, year = {{2015}}, } @inproceedings{20007, author = {{Hamann, Heiko and Karsai, Istvan and Schmickl, Thomas and Hilbun, Allison}}, booktitle = {{Symposium on Biomathematics and Ecology: Education and Research}}, title = {{{The common stomach: Organizing task allocation in wasp societies}}}, year = {{2014}}, } @inproceedings{20008, author = {{Hamann, Heiko and Valentini, Gabriele}}, booktitle = {{Ninth Int. Conf. on Swarm Intelligence (ANTS 2014)}}, isbn = {{9783319099514}}, issn = {{0302-9743}}, title = {{{Swarm in a Fly Bottle: Feedback-Based Analysis of Self-organizing Temporary Lock-ins}}}, doi = {{10.1007/978-3-319-09952-1_15}}, year = {{2014}}, } @article{20120, abstract = {{A grand challenge in the field of artificial life is to find a general theory of emergent self-organizing systems. In swarm systems most of the observed complexity is based on motion of simple entities. Similarly, statistical mechanics focuses on collective properties induced by the motion of many interacting particles. In this article we apply methods from statistical mechanics to swarm systems. We try to explain the emergent behavior of a simulated swarm by applying methods based on the fluctuation theorem. Empirical results indicate that swarms are able to produce negative entropy within an isolated subsystem due to frozen accidents. Individuals of a swarm are able to locally detect fluctuations of the global entropy measure and store them, if they are negative entropy productions. By accumulating these stored fluctuations over time the swarm as a whole is producing negative entropy and the system ends up in an ordered state. We claim that this indicates the existence of an inverted fluctuation theorem for emergent self-organizing dissipative systems. This approach bears the potential of general applicability.}}, author = {{Hamann, Heiko and Schmickl, Thomas and Crailsheim, Karl}}, journal = {{Artificial Life}}, number = {{1}}, pages = {{77--93}}, title = {{{Analysis of Swarm Behaviors Based on an Inversion of the Fluctuation Theorem}}}, doi = {{10.1162/ARTL_a_00097}}, volume = {{20}}, year = {{2014}}, } @inproceedings{20121, abstract = {{Collective decision making in self-organized systems is challenging because it relies on local perception and local communication. Globally defined qualities such as consensus time and decision accuracy are both difficult to predict and difficult to guarantee. We present the weighted voter model which implements a self-organized collective decision making process. We provide an ODE model, a master equation model (numerically solved by the Gillespie algorithm), and agent-based simulations of the proposed decision-making strategy. This set of models enables us to investigate the system behavior in the thermodynamic limit and to investigate finite-size effects due to random fluctuations. Based on our results, we give minimum requirements to guarantee consensus on the optimal decision, a minimum swarm size to guarantee a certain accuracy, and we show that the proposed approach scales with system size and is robust to noise.}}, author = {{Dorigo, Marco and Hamann, Heiko and Valentini, Gabriele and Lomuscio, Alessio and Scerri, Paul and Bazzan, Ana and Huhns, Michael}}, booktitle = {{Proceedings of the 13th Int. Conf. on Autonomous Agents and Multiagent Systems (AAMAS 2014)}}, title = {{{Self-Organized Collective Decision Making: The Weighted Voter Model}}}, year = {{2014}}, } @inproceedings{20126, author = {{Hamann, Heiko}}, booktitle = {{Int. Conf. on Genetic and Evolutionary Computation (GECCO 2014)}}, pages = {{31--32}}, title = {{{Evolving Prediction Machines: Collective Behaviors Based on Minimal Surprisal}}}, doi = {{10.1145/2598394.2598507}}, year = {{2014}}, } @inproceedings{20127, author = {{Birattari, Mauro and Dorigo, Marco and Hamann, Heiko and Garnier, Simon and Montes de Oca, Marco and Solnon, Christine and Stuetzle, Thomas and Ding, Hongli}}, booktitle = {{Ninth Int. Conf. on Swarm Intelligence (ANTS 2014)}}, pages = {{262--269}}, title = {{{Sorting in Swarm Robots Using Communication-Based Cluster Size Estimation}}}, doi = {{10.1007/978-3-319-09952-1_25}}, volume = {{8667}}, year = {{2014}}, } @inbook{20128, author = {{Khaluf, Yara and Dorigo, Marco and Hamann, Heiko and Valentini, Gabriele and Bartz-Beielstein, T.}}, booktitle = {{13th International Conference on Parallel Problem Solving from Nature (PPSN 2014)}}, pages = {{181--190}}, publisher = {{Springer}}, title = {{{Derivation of a Micro-Macro Link for Collective Decision-Making Systems: Uncover Network Features Based on Drift Measurements}}}, doi = {{10.1007/978-3-319-10762-2_18}}, volume = {{8672}}, year = {{2014}}, } @inproceedings{20129, author = {{Hamann, Heiko and Sayama, Hiroki and Rieffel, John and Risi, Sebastian and Doursat, Rene and Lipson, Hod}}, booktitle = {{14th Int. Conf. on the Synthesis and Simulation of Living Systems (ALIFE 2014)}}, pages = {{344--351}}, publisher = {{MIT Press}}, title = {{{Evolution of Collective Behaviors by Minimizing Surprise}}}, doi = {{10.7551/978-0-262-32621-6-ch055}}, year = {{2014}}, } @inproceedings{20130, author = {{Cervera, Enric and Khaluf, Yara and Birattari, Mauro and Hamann, Heiko and Pobil, Angel P. del and Chinellato, Eris and Martinez-Martin, Ester and Hallam, John and Morales, Antonio}}, booktitle = {{Simulation of Adaptive Behavior (SAB 2014)}}, pages = {{270--279}}, title = {{{A Swarm Robotics Approach to Task Allocation Under Soft Deadlines and Negligible Switching Costs}}}, doi = {{10.1007/978-3-319-08864-8_26}}, volume = {{8575}}, year = {{2014}}, } @inproceedings{368, abstract = {{We consider the problem of scheduling a number of jobs on $m$ identical processors sharing a continuously divisible resource. Each job j comes with a resource requirement r_j \in {0,1}. The job can be processed at full speed if granted its full resource requirement. If receiving only an x-portion of r_j, it is processed at an x-fraction of the full speed. Our goal is to find a resource assignment that minimizes the makespan (i.e., the latest completion time). Variants of such problems, relating the resource assignment of jobs to their \emph{processing speeds}, have been studied under the term discrete-continuous scheduling. Known results are either very pessimistic or heuristic in nature.In this paper, we suggest and analyze a slightly simplified model. It focuses on the assignment of shared continuous resources to the processors. The job assignment to processors and the ordering of the jobs have already been fixed. It is shown that, even for unit size jobs, finding an optimal solution is NP-hard if the number of processors is part of the input. Positive results for unit size jobs include an efficient optimal algorithm for 2 processors. Moreover, we prove that balanced schedules yield a 2-1/m-approximation for a fixed number of processors. Such schedules are computed by our GreedyBalance algorithm, for which the bound is tight.}}, author = {{Brinkmann, Andre and Kling, Peter and Meyer auf der Heide, Friedhelm and Nagel, Lars and Riechers, Sören and Suess, Tim }}, booktitle = {{Proceedings of the 26th ACM Symposium on Parallelism in Algorithms and Architectures (SPAA)}}, pages = {{128--137}}, title = {{{Scheduling Shared Continuous Resources on Many-Cores}}}, doi = {{10.1145/2612669.2612698}}, year = {{2014}}, } @inproceedings{370, abstract = {{Max-min fairness (MMF) is a widely known approach to a fair allocation of bandwidth to each of the users in a network. This allocation can be computed by uniformly raising the bandwidths of all users without violating capacity constraints. We consider an extension of these allocations by raising the bandwidth with arbitrary and not necessarily uniform time-depending velocities (allocation rates). These allocations are used in a game-theoretic context for routing choices, which we formalize in progressive filling games (PFGs).We present a variety of results for equilibria in PFGs. We show that these games possess pure Nash and strong equilibria. While computation in general is NP-hard, there are polynomial-time algorithms for prominent classes of Max-Min-Fair Games (MMFG), including the case when all users have the same source-destination pair. We characterize prices of anarchy and stability for pure Nash and strong equilibria in PFGs and MMFGs when players have different or the same source-destination pairs. In addition, we show that when a designer can adjust allocation rates, it is possible to design games with optimal strong equilibria. Some initial results on polynomial-time algorithms in this direction are also derived. }}, author = {{Harks, Tobias and Höfer, Martin and Schewior, Kevin and Skopalik, Alexander}}, booktitle = {{Proceedings of the 33rd Annual IEEE International Conference on Computer Communications (INFOCOM'14)}}, pages = {{352--360}}, title = {{{Routing Games with Progressive Filling}}}, doi = {{10.1109/TNET.2015.2468571}}, year = {{2014}}, } @misc{373, author = {{Pahl, David}}, publisher = {{Universität Paderborn}}, title = {{{Reputationssysteme für zusammengesetzte Dienstleistungen}}}, year = {{2014}}, } @inproceedings{379, abstract = {{In the leasing variant of Set Cover presented by Anthony et al.[1], elements U arrive over time and must be covered by sets from a familyF of subsets of U. Each set can be leased for K different periods of time.Let |U| = n and |F| = m. Leasing a set S for a period k incurs a cost ckS and allows S to cover its elements for the next lk time steps. The objectiveis to minimize the total cost of the sets leased, such that elements arrivingat any time t are covered by sets which contain them and are leased duringtime t. Anthony et al. [1] gave an optimal O(log n)-approximation forthe problem in the offline setting, unless P = NP [22]. In this paper, wegive randomized algorithms for variants of Set Cover Leasing in the onlinesetting, including a generalization of Online Set Cover with Repetitionspresented by Alon et al. [2], where elements appear multiple times andmust be covered by a different set at each arrival. Our results improve theO(log2(mn)) competitive factor of Online Set Cover with Repetitions [2]to O(log d log(dn)) = O(logmlog(mn)), where d is the maximum numberof sets an element belongs to.}}, author = {{Abshoff, Sebastian and Markarian, Christine and Meyer auf der Heide, Friedhelm}}, booktitle = {{Proceedings of the 8th Annual International Conference on Combinatorial Optimization and Applications (COCOA)}}, pages = {{25--34}}, title = {{{Randomized Online Algorithms for Set Cover Leasing Problems}}}, doi = {{10.1007/978-3-319-12691-3_3}}, year = {{2014}}, } @inproceedings{380, abstract = {{Network creation games model the creation and usage costs of networks formed by n selfish nodes. Each node v can buy a set of edges, each for a fixed price α > 0. Its goal is to minimize its private costs, i.e., the sum (SUM-game, Fabrikant et al., PODC 2003) or maximum (MAX-game, Demaine et al., PODC 2007) of distances from v to all other nodes plus the prices of the bought edges. The above papers show the existence of Nash equilibria as well as upper and lower bounds for the prices of anarchy and stability. In several subsequent papers, these bounds were improved for a wide range of prices α. In this paper, we extend these models by incorporating quality-of-service aspects: Each edge cannot only be bought at a fixed quality (edge length one) for a fixed price α. Instead, we assume that quality levels (i.e., edge lengths) are varying in a fixed interval [βˇ,β^] , 0 series = {LNCS}}}, author = {{Cord-Landwehr, Andreas and Mäcker, Alexander and Meyer auf der Heide, Friedhelm}}, booktitle = {{Proceedings of the 10th International Conference on Web and Internet Economics (WINE)}}, pages = {{423--428}}, title = {{{Quality of Service in Network Creation Games}}}, doi = {{10.1007/978-3-319-13129-0_34}}, year = {{2014}}, } @inproceedings{17659, author = {{Polevoy, Gleb and Trajanovski, Stojan and de Weerdt, Mathijs M.}}, booktitle = {{Proceedings of the 2014 International Conference on Autonomous Agents and Multi-agent Systems}}, isbn = {{978-1-4503-2738-1}}, keywords = {{competition, equilibrium, market, models, shared effort games, simulation}}, pages = {{861--868}}, publisher = {{International Foundation for Autonomous Agents and Multiagent Systems}}, title = {{{Nash Equilibria in Shared Effort Games}}}, year = {{2014}}, } @inproceedings{17660, author = {{Polevoy, Gleb and de Weerdt, Mathijs M.}}, booktitle = {{Proceedings of the 2014 International Conference on Autonomous Agents and Multi-agent Systems}}, isbn = {{978-1-4503-2738-1}}, keywords = {{dynamics, emotion modeling, negotiation, network interaction, shared effort game}}, pages = {{1741--1742}}, publisher = {{International Foundation for Autonomous Agents and Multiagent Systems}}, title = {{{Improving Human Interaction in Crowdsensing}}}, year = {{2014}}, } @inproceedings{17661, author = {{King, Thomas C. and Liu, Qingzhi and Polevoy, Gleb and de Weerdt, Mathijs and Dignum, Virginia and van Riemsdijk, M. Birna and Warnier, Martijn}}, booktitle = {{Proceedings of the 2014 International Conference on Autonomous Agents and Multi-agent Systems}}, isbn = {{978-1-4503-2738-1}}, keywords = {{crowd-sensing, crowdsourcing, data aggregation, game theory, norms, reciprocation, self interested agents, simulation}}, pages = {{1651--1652}}, publisher = {{International Foundation for Autonomous Agents and Multiagent Systems}}, title = {{{Request Driven Social Sensing}}}, year = {{2014}}, } @article{17662, author = {{Polevoy, Gleb and Smorodinsky, Rann and Tennenholtz, Moshe}}, issn = {{2167-8375}}, journal = {{ACM Trans. Econ. Comput.}}, keywords = {{Competition, efficiency, equilibrium, market, social welfare}}, number = {{1}}, pages = {{1:1--1:16}}, publisher = {{ACM}}, title = {{{Signaling Competition and Social Welfare}}}, doi = {{10.1145/2560766}}, volume = {{2}}, year = {{2014}}, } @phdthesis{19039, author = {{Petring, Ralf}}, title = {{{Multi-Algorithmen-Rendering: Darstellung heterogener 3-D-Szenen in Echtzeit}}}, 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{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}}, } @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{395, abstract = {{We consider a multilevel network game, where nodes can improvetheir communication costs by connecting to a high-speed network.The n nodes are connected by a static network and each node can decideindividually to become a gateway to the high-speed network. The goalof a node v is to minimize its private costs, i.e., the sum (SUM-game) ormaximum (MAX-game) of communication distances from v to all othernodes plus a fixed price α > 0 if it decides to be a gateway. Between gatewaysthe communication distance is 0, and gateways also improve othernodes’ distances by behaving as shortcuts. For the SUM-game, we showthat for α ≤ n − 1, the price of anarchy is Θ (n/√α) and in this rangeequilibria always exist. In range α ∈ (n−1, n(n−1)) the price of anarchyis Θ(√α), and for α ≥ n(n − 1) it is constant. For the MAX-game, weshow that the price of anarchy is either Θ (1 + n/√α), for α ≥ 1, orelse 1. Given a graph with girth of at least 4α, equilibria always exist.Concerning the dynamics, both games are not potential games. For theSUM-game, we even show that it is not weakly acyclic.}}, author = {{Abshoff, Sebastian and Cord-Landwehr, Andreas and Jung, Daniel and Skopalik, Alexander}}, booktitle = {{Proceedings of the 10th International Conference on Web and Internet Economics (WINE)}}, pages = {{435--440}}, title = {{{Multilevel Network Games}}}, doi = {{10.1007/978-3-319-13129-0_36}}, year = {{2014}}, } @inproceedings{412, abstract = {{In this paper we present and analyze HSkip+, a self-stabilizing overlay network for nodes with arbitrary heterogeneous bandwidths. HSkip+ has the same topology as the Skip+ graph proposed by Jacob et al. [PODC 2009] but its self-stabilization mechanism significantly outperforms the self-stabilization mechanism proposed for Skip+. Also, the nodes are now ordered according to their bandwidths and not according to their identifiers. Various other solutions have already been proposed for overlay networks with heterogeneous bandwidths, but they are not self-stabilizing. In addition to HSkip+ being self-stabilizing, its performance is on par with the best previous bounds on the time and work for joining or leaving a network of peers of logarithmic diameter and degree and arbitrary bandwidths. Also, the dilation and congestion for routing messages is on par with the best previous bounds for such networks, so that HSkip+ combines the advantages of both worlds. Our theoretical investigations are backed by simulations demonstrating that HSkip+ is indeed performing much better than Skip+ and working correctly under high churn rates.}}, author = {{Feldotto, Matthias and Scheideler, Christian and Graffi, Kalman}}, booktitle = {{Proceedings of the 14th IEEE International Conference on Peer-to-Peer Computing (P2P)}}, pages = {{1--10}}, title = {{{HSkip+: A Self-Stabilizing Overlay Network for Nodes with Heterogeneous Bandwidths}}}, doi = {{10.1109/P2P.2014.6934300}}, year = {{2014}}, } @phdthesis{431, abstract = {{In meiner Dissertation besch{\"a}ftige ich mich mit dem Entwurf und der Analyse energieeffizienter Schedulingalgorithmen, insbesondere f{\"u}r sogenannte Speed-Scaling Modelle. Diese stellen das theoretische Pendant von Techniken wie AMDs PowerNOW! und Intels SpeedStep dar, welche es erlauben die Geschwindigkeit von Prozessoren zur Laufzeit an die derzeitigen Bedingungen anzupassen. Theoretische Untersuchungen solcher Modelle sind auf eine Arbeit von Yao, Demers und Shenker (FOCS'95) zur{\"u}ckzuf{\"u}hren. Hier kombinieren die Autoren klassisches Deadline-Scheduling mit einem Prozessor der Speed-Scaling beherrscht. Es gilt Jobs verschiedener Gr{\"o}ße fristgerecht abzuarbeiten und die dabei verwendete Energie zu minimieren. Der Energieverbrauch des Prozessors wird durch eine konvexe Funktion $\POW\colon\R_{\geq0}\to\R_{\geq0}$ modelliert, welche die Geschwindigkeit auf den Energieverbrauch abbildet.Meine Dissertation betrachtet verschiedene Varianten des urspr{\"u}nglichen Speed-Scaling Modells. Forschungsrelevante Ergebnisse sind in den Kapiteln 3 bis 6 zu finden und erstrecken sich {\"u}ber die im Folgenden beschriebenen Aspekte:- Kapitel 3 und 4 betrachten verschiedene \emph{Price-Collecting} Varianten des Originalproblems. Hier d{\"u}rfen einzelne Deadlines verfehlt werden, sofern eine jobabh{\"a}ngige Strafe gezahlt wird. Ich entwerfe insbesondere Online-Algorithmen mit einer beweisbar guten Competitiveness. Dabei liefern meine Ergebnisse substantielle Verbesserungen bestehender Arbeiten und erweitern diese unter Anderem auf Szenarien mit mehreren Prozessoren.- In Kapitel 5 wird statt des klassischen Deadline-Schedulings eine Linearkombination der durchschnittlichen Antwortzeit und des Energieverbrauchs betrachtet. Die Frage, ob dieses Problem NP-schwer ist, stellt eine der zentralen Forschungsfragen in diesem Gebiet dar. F{\"u}r eine relaxierte Form dieser Frage entwerfe ich einen effizienter Algorithmus und beweise seine Optimalit{\"a}t.- Das letzte Kapitel betrachtet ein Modell, welches – auf den ersten Blick – nicht direkt zur Speed-Scaling Literatur z{\"a}hlt. Hier geht es stattdessen um ein allgemeines Resource-Constrained Scheduling, in dem sich die Prozessoren zusammen eine gemeinsame, beliebig aufteilbare Ressource teilen. Ich untersuche die Komplexit{\"a}t des Problems und entwerfe verschiedene Approximationsalgorithmen.}}, author = {{Kling, Peter}}, publisher = {{Universität Paderborn}}, title = {{{Energy-efficient Scheduling Algorithms}}}, year = {{2014}}, } @inproceedings{435, abstract = {{We give a polynomial time algorithm to compute an optimal energy and fractional weighted flow trade-off schedule for a speed-scalable processor with discrete speeds.Our algorithm uses a geometric approach that is based on structural properties obtained from a primal-dual formulation of the problem.}}, author = {{Antoniadis, Antonios and Barcelo, Neal and Consuegra, Mario and Kling, Peer and Nugent, Michael and Pruhs, Kirk and Scquizzato, Michele}}, booktitle = {{Proceedings of the 31st Symposium on Theoretical Aspects of Computer Science (STACS)}}, pages = {{63----74}}, title = {{{Efficient Computation of Optimal Energy and Fractional Weighted Flow Trade-off Schedules}}}, doi = {{10.4230/LIPIcs.STACS.2014.63}}, year = {{2014}}, } @book{16870, editor = {{Flocchini, Paola and Gao, Jie and Kranakis, Evangelos and Meyer auf der Heide, Friedhelm}}, isbn = {{9783642453458}}, issn = {{0302-9743}}, publisher = {{Springer}}, title = {{{Algorithms for Sensor Systems - 9th International Symposium on Algorithms and Experiments for Sensor Systems, Wireless Networks and Distributed Robotics, {ALGOSENSORS} 2013}}}, doi = {{10.1007/978-3-642-45346-5}}, volume = {{8243}}, year = {{2014}}, } @inbook{16394, author = {{Lukovszki, Tamás and Meyer auf der Heide, Friedhelm}}, booktitle = {{Lecture Notes in Computer Science}}, isbn = {{9783319144719}}, issn = {{0302-9743}}, title = {{{Fast Collisionless Pattern Formation by Anonymous, Position-Aware Robots}}}, doi = {{10.1007/978-3-319-14472-6_17}}, year = {{2014}}, } @inbook{16395, author = {{Abshoff, Sebastian and Meyer auf der Heide, Friedhelm}}, booktitle = {{Structural Information and Communication Complexity}}, isbn = {{9783319096193}}, issn = {{0302-9743}}, title = {{{Continuous Aggregation in Dynamic Ad-Hoc Networks}}}, doi = {{10.1007/978-3-319-09620-9_16}}, year = {{2014}}, } @article{19981, author = {{Mertsching, Bärbel and Divband Soorati, Mohammad and Kotthauser, Tobias}}, journal = {{IEEE International Conference on Robotics and Biomimetics (ROBIO)}}, pages = {{661--667}}, title = {{{Automatic Reconstruction of Polygonal Room Models from 3D Point Clouds}}}, year = {{2013}}, } @article{20148, author = {{Hamann, Heiko and Karsai, Istvan and Schmickl, Thomas}}, journal = {{Bulletin of Mathematical Biology}}, number = {{7}}, pages = {{1181--1206}}, title = {{{Time delay implies cost on task switching: A model to investigate the efficiency of task partitioning}}}, doi = {{10.1007/s11538-013-9851-4 }}, volume = {{75}}, year = {{2013}}, } @article{20150, author = {{Hamann, Heiko and Schmickl, Thomas and Stradner, Jürgen and Crailsheim, Karl and Thenius, Ronald and Zahadat, Payam}}, journal = {{Chaos, Solitons & Fractals}}, pages = {{100--114}}, title = {{{Algorithmic Requirements for Swarm Intelligence in Differently Coupled Collective Systems}}}, doi = {{10.1016/j.chaos.2013.01.011}}, volume = {{50}}, year = {{2013}}, } @inproceedings{20151, author = {{Hamann, Heiko and Schmickl, Thomas and Stradner, Jürgen and Schwarzer, Christopher and Michiels, Nico K. and Esparcia-Alcazar, Anna Isabel}}, booktitle = {{Applications of Evolutionary Computation - 16th European Conference (EvoApplications 2013)}}, pages = {{579--588}}, title = {{{Virtual Spatiality in Agent Controllers: Encoding Compartmentalization}}}, doi = {{10.1007/978-3-642-37192-9_58}}, volume = {{7835}}, year = {{2013}}, }