@inproceedings{215, abstract = {{We present three robust overlay networks: First, we present a network that organizes the nodes into an expander and is resistant to even massive adversarial churn. Second, we develop a network based on the hypercube that maintains connectivity under adversarial DoS-attacks. For the DoS-attacks we use the notion of a Omega(log log n)-late adversary which only has access to topological information that is at least Omega(log log n) rounds old. Finally, we develop a network that combines both churn- and DoS-resistance. The networks gain their robustness through constant network reconfiguration, i.e., the topology of the networks changes constantly. Our reconguration algorithms are based on node sampling primitives for expanders and hypercubes that allow each node to sample a logarithmic number of nodes uniformly at random in O(log log n) communication rounds. These primitives are specific to overlay networks and their optimal runtime represents an exponential improvement over known techniques. Our results have a wide range of applications, for example in the area of scalable and robust peer-to-peer systems.}}, author = {{Drees, Maximilian and Gmyr, Robert and Scheideler, Christian}}, booktitle = {{Proceedings of the 28th ACM Symposium on Parallelism in Algorithms and Architectures (SPAA)}}, pages = {{417----427}}, title = {{{Churn- and DoS-resistant Overlay Networks Based on Network Reconfiguration}}}, doi = {{10.1145/2935764.2935783}}, year = {{2016}}, } @inproceedings{17655, author = {{Polevoy, Gleb and de Weerdt, M.M. and Jonker, C.M.}}, booktitle = {{Proceedings of the 2016 European Conference on Artificial Intelligence}}, keywords = {{agents, action, repeated reciprocation, fixed, floating, network, Nash equilibrium, social welfare, price of anarchy, price of stability, convex combination}}, pages = {{417--425}}, title = {{{The Game of Reciprocation Habits}}}, doi = {{10.3233/978-1-61499-672-9-417}}, volume = {{Volume 285: ECAI 2016}}, year = {{2016}}, } @inproceedings{17656, author = {{Polevoy, Gleb and de Weerdt, Mathijs and Jonker, Catholijn}}, booktitle = {{Proceedings of the 2016 International Conference on Autonomous Agents and Multiagent Systems}}, isbn = {{978-1-4503-4239-1}}, keywords = {{agent's influence, behavior, convergence, perron-frobenius, reciprocal interaction, repeated reciprocation}}, pages = {{1431--1432}}, publisher = {{International Foundation for Autonomous Agents and Multiagent Systems}}, title = {{{The Convergence of Reciprocation}}}, year = {{2016}}, } @inproceedings{177, abstract = {{Efficiently parallelizable parameterized problems have been classified as being either in the class FPP (fixed-parameter parallelizable) or the class PNC (parameterized analog of NC), which contains FPP as a subclass. In this paper, we propose a more restrictive class of parallelizable parameterized problems called fixed-parameter parallel-tractable (FPPT). For a problem to be in FPPT, it should possess an efficient parallel algorithm not only from a theoretical standpoint but in practice as well. The primary distinction between FPPT and FPP is the parallel processor utilization, which is bounded by a polynomial function in the case of FPPT. We initiate the study of FPPT with the well-known k-vertex cover problem. In particular, we present a parallel algorithm that outperforms the best known parallel algorithm for this problem: using O(m) instead of O(n2) parallel processors, the running time improves from 4logn+O(kk) to O(k⋅log3n), where m is the number of edges, n is the number of vertices of the input graph, and k is an upper bound of the size of the sought vertex cover. We also note that a few P-complete problems fall into FPPT including the monotone circuit value problem (MCV) when the underlying graphs are bounded by a constant Euler genus.}}, author = {{Abu-Khzam, Faisal N. and Li, Shouwei and Markarian, Christine and Meyer auf der Heide, Friedhelm and Podlipyan, Pavel}}, booktitle = {{Proceedings of the 10th International Conference on Combinatorial Optimization and Applications (COCOA)}}, pages = {{477--488}}, title = {{{On the Parameterized Parallel Complexity and the Vertex Cover Problem}}}, doi = {{10.1007/978-3-319-48749-6_35}}, year = {{2016}}, } @misc{187, booktitle = {{Transactions on Parallel Computing (TOPC)}}, editor = {{Meyer auf der Heide, Friedhelm}}, number = {{1}}, pages = {{1}}, title = {{{Introduction to the Special Issue on SPAA 2014}}}, doi = {{10.1145/2936716}}, year = {{2016}}, } @inproceedings{207, abstract = {{We consider a scheduling problem where machines need to be rented from the cloud in order to process jobs. There are two types of machines available which can be rented for machine-type dependent prices and for arbitrary durations. However, a machine-type dependent setup time is required before a machine is available for processing. Jobs arrive online over time, have machine-type dependent sizes and have individual deadlines. The objective is to rent machines and schedule jobs so as to meet all deadlines while minimizing the rental cost. Since we observe the slack of jobs to have a fundamental influence on the competitiveness, we study the model when instances are parameterized by their (minimum) slack. An instance is called to have a slack of $\beta$ if, for all jobs, the difference between the job's release time and the latest point in time at which it needs to be started is at least $\beta$. While for $\beta series = {LNCS}}}, author = {{Mäcker, Alexander and Malatyali, Manuel and Meyer auf der Heide, Friedhelm and Riechers, Sören}}, booktitle = {{Proceedings of the 10th Annual International Conference on Combinatorial Optimization and Applications (COCOA)}}, pages = {{578----592}}, title = {{{Cost-efficient Scheduling on Machines from the Cloud}}}, doi = {{10.1007/978-3-319-48749-6_42}}, year = {{2016}}, } @inproceedings{209, abstract = {{We study a new class of games which generalizes congestion games and its bottleneck variant. We introduce congestion games with mixed objectives to model network scenarios in which players seek to optimize for latency and bandwidths alike. We characterize the existence of pure Nash equilibria (PNE) and the convergence of improvement dynamics. For games that do not possess PNE we give bounds on the approximation ratio of approximate pure Nash equilibria.}}, author = {{Feldotto, Matthias and Leder, Lennart and Skopalik, Alexander}}, booktitle = {{Proceedings of the 10th Annual International Conference on Combinatorial Optimization and Applications (COCOA)}}, pages = {{655----669}}, title = {{{Congestion Games with Mixed Objectives}}}, doi = {{10.1007/978-3-319-48749-6_47}}, year = {{2016}}, } @misc{5406, author = {{Bülling, Jonas}}, title = {{{Parallelisierung von Algorithmen zur IR-Luftbildanalyse von Laubholzmischbeständen zur Verifizierung der Ausbreitung von Eichenkomplexschäden}}}, year = {{2016}}, } @misc{5407, author = {{Koepe, Jörn}}, publisher = {{Universität Paderborn}}, title = {{{Price-Based Allocation Games}}}, year = {{2016}}, } @misc{688, author = {{Kutzias, Damian}}, publisher = {{Universität Paderborn}}, title = {{{Friendship Processes in Network Creation Games}}}, year = {{2016}}, } @misc{689, author = {{Schaefer, Johannes Sebastian}}, publisher = {{Universität Paderborn}}, title = {{{Routing Algorithms on Delayed Networks for Disaster Management Support}}}, year = {{2016}}, } @unpublished{16450, abstract = {{In this paper, we solve the local gathering problem of a swarm of $n$ indistinguishable, point-shaped robots on a two dimensional grid in asymptotically optimal time $\mathcal{O}(n)$ in the fully synchronous $\mathcal{FSYNC}$ time model. Given an arbitrarily distributed (yet connected) swarm of robots, the gathering problem on the grid is to locate all robots within a $2\times 2$-sized area that is not known beforehand. Two robots are connected if they are vertical or horizontal neighbors on the grid. The locality constraint means that no global control, no compass, no global communication and only local vision is available; hence, a robot can only see its grid neighbors up to a constant $L_1$-distance, which also limits its movements. A robot can move to one of its eight neighboring grid cells and if two or more robots move to the same location they are \emph{merged} to be only one robot. The locality constraint is the significant challenging issue here, since robot movements must not harm the (only globally checkable) swarm connectivity. For solving the gathering problem, we provide a synchronous algorithm -- executed by every robot -- which ensures that robots merge without breaking the swarm connectivity. In our model, robots can obtain a special state, which marks such a robot to be performing specific connectivity preserving movements in order to allow later merge operations of the swarm. Compared to the grid, for gathering in the Euclidean plane for the same robot and time model the best known upper bound is $\mathcal{O}(n^2)$.}}, author = {{Cord-Landwehr, Andreas and Fischer, Matthias and Jung, Daniel and Meyer auf der Heide, Friedhelm}}, booktitle = {{arXiv:1602.03303}}, title = {{{Asymptotically Optimal Gathering on a Grid}}}, year = {{2016}}, } @inproceedings{169, abstract = {{We apply methods of genetic programming to a general problem from software engineering, namely example-based generation of specifications. In particular, we focus on model transformation by example. The definition and implementation of model transformations is a task frequently carried out by domain experts, hence, a (semi-)automatic approach is desirable. This application is challenging because the underlying search space has rich semantics, is high-dimensional, and unstructured. Hence, a computationally brute-force approach would be unscalable and potentially infeasible. To address that problem, we develop a sophisticated approach of designing complex mutation operators. We define ‘patterns’ for constructing mutation operators and report a successful case study. Furthermore, the code of the evolved model transformation is required to have high maintainability and extensibility, that is, the code should be easily readable by domain experts. We report an evaluation of this approach in a software engineering case study.}}, author = {{Kühne, Thomas and Hamann, Heiko and Arifulina, Svetlana and Engels, Gregor}}, booktitle = {{Proceedings of the 19th European Conference on Genetic Programming (EuroGP 2016)}}, pages = {{278----293}}, title = {{{Patterns for Constructing Mutation Operators: Limiting the Search Space in a Software Engineering Application}}}, doi = {{10.1007/978-3-319-30668-1_18}}, year = {{2016}}, } @misc{1082, author = {{Handirk, Tobias}}, publisher = {{Universität Paderborn}}, title = {{{Über die Rolle von Informationen in Verkehrsnetzwerken}}}, year = {{2016}}, } @phdthesis{154, author = {{Cord-Landwehr, Andreas}}, isbn = {{978-3-942647-72-4}}, publisher = {{Verlagsschriftenreihe des Heinz Nixdorf Instituts, Paderborn}}, title = {{{Selfish Network Creation - On Variants of Network Creation Games}}}, volume = {{353}}, year = {{2016}}, } @inproceedings{157, abstract = {{Consider a scheduling problem in which a set of jobs with interjob communication, canonically represented by a weighted tree, needs to be scheduled on m parallel processors interconnected by a shared communication channel. In each time step, we may allow any processed job to use a certain capacity of the channel in order to satisfy (parts of) its communication demands to adjacent jobs processed in parallel. The goal is to find a schedule that minimizes the makespan and in which communication demands of all jobs are satisfied.We show that this problem is NP-hard in the strong sense even if the number of processors and the maximum degree of the underlying tree is constant.Consequently, we design and analyze simple approximation algorithms with asymptotic approximation ratio 2-2/m in case of paths and a ratio of 5/2 in case of arbitrary trees.}}, author = {{König, Jürgen and Mäcker, Alexander and Meyer auf der Heide, Friedhelm and Riechers, Sören}}, booktitle = {{Proceedings of the 10th Annual International Conference on Combinatorial Optimization and Applications (COCOA)}}, pages = {{563----577}}, title = {{{Scheduling with Interjob Communication on Parallel Processors}}}, doi = {{10.1007/978-3-319-48749-6_41}}, year = {{2016}}, } @article{159, abstract = {{Abstract—Max-min fairness (MMF) is a widely known approachto a fair allocation of bandwidth to each of the usersin a network. This allocation can be computed by uniformlyraising the bandwidths of all users without violating capacityconstraints. We consider an extension of these allocations byraising the bandwidth with arbitrary and not necessarily uniformtime-depending velocities (allocation rates). These allocationsare used in a game-theoretic context for routing choices, whichwe formalize in progressive filling games (PFGs). We present avariety of results for equilibria in PFGs. We show that these gamespossess pure Nash and strong equilibria. While computation ingeneral is NP-hard, there are polynomial-time algorithms forprominent classes of Max-Min-Fair Games (MMFG), includingthe case when all users have the same source-destination pair.We characterize prices of anarchy and stability for pure Nashand strong equilibria in PFGs and MMFGs when players havedifferent or the same source-destination pairs. In addition, weshow that when a designer can adjust allocation rates, it is possibleto design games with optimal strong equilibria. Some initial resultson polynomial-time algorithms in this direction are also derived.}}, author = {{Harks, Tobias and Höfer, Martin and Schewior, Kevin and Skopalik, Alexander}}, journal = {{IEEE/ACM Transactions on Networking}}, number = {{4}}, pages = {{2553 -- 2562}}, publisher = {{IEEE}}, title = {{{Routing Games With Progressive Filling}}}, doi = {{10.1109/TNET.2015.2468571}}, year = {{2016}}, } @inproceedings{149, abstract = {{In this paper we consider a strategic variant of the online facility location problem. Given is a graph in which each node serves two roles: it is a strategic client stating requests as well as a potential location for a facility. In each time step one client states a request which induces private costs equal to the distance to the closest facility. Before serving, the clients may collectively decide to open new facilities, sharing the corresponding price. Instead of optimizing the global costs, each client acts selfishly. The prices of new facilities vary between nodes and also change over time, but are always bounded by some fixed value α. Both the requests as well as the facility prices are given by an online sequence and are not known in advance.We characterize the optimal strategies of the clients and analyze their overall performance in comparison to a centralized offline solution. If all players optimize their own competitiveness, the global performance of the system is O(√α⋅α) times worse than the offline optimum. A restriction to a natural subclass of strategies improves this result to O(α). We also show that for fixed facility costs, we can find strategies such that this bound further improves to O(√α).}}, author = {{Drees, Maximilian and Feldkord, Björn and Skopalik, Alexander}}, booktitle = {{Proceedings of the 10th Annual International Conference on Combinatorial Optimization and Applications (COCOA)}}, pages = {{593----607}}, title = {{{Strategic Online Facility Location}}}, doi = {{10.1007/978-3-319-48749-6_43}}, year = {{2016}}, } @proceedings{163, editor = {{Dressler, Falko and Meyer auf der Heide, Friedhelm}}, location = {{Paderborn, Germany}}, publisher = {{ACM}}, title = {{{Proceedings of the 17th ACM International Symposium on Mobile Ad Hoc Networking and Computing (MobiHoc)}}}, doi = {{10.1145/2942358}}, year = {{2016}}, } @inproceedings{16351, abstract = {{Defining, measuring, and comparing the quality and efficiency of rendering algorithms in computer graphics is a demanding challenge: quality measures are often application specific and efficiency is strongly influenced by properties of the rendered scene and the used hardware. We survey the currently employed evaluation methods for AQ1 the development process of rendering algorithms. Then, we present our PADrend framework, which supports systematic and flexible development, evaluation, adaptation, and comparison of rendering algorithms, and provides a comfortable and easy-to-use platform for developers of rendering algorithms. The system includes a new evaluation method to improve the objectivity of experimental evaluations of rendering algorithms. }}, author = {{Fischer, Matthias and Jähn, Claudius and Meyer auf der Heide, Friedhelm and Petring, Ralf}}, booktitle = {{Algorithm Engineering}}, editor = {{Kliemann, Lasse and Sanders, Peter}}, pages = {{226--244}}, publisher = {{Springer}}, title = {{{Algorithm Engineering Aspects of Real-Time Rendering Algorithms}}}, doi = {{10.1007/978-3-319-49487-6_7 }}, volume = {{9220}}, year = {{2016}}, }