@phdthesis{270,
author = {Abshoff, Sebastian},
publisher = {Universität Paderborn},
title = {{On the Complexity of Fundamental Problems in Dynamic Ad-hoc Networks}},
year = {2015},
}
@inproceedings{19960,
abstract = {Besides the life-as-it-could-be driver of artificial life research there is also the concept of extending natural life by creating hybrids or mixed societies that are built from natural and artificial components. In this paper we motivate and present the research program of the project flora robotica. Our objective is to develop and to investigate closely linked symbiotic relationships between robots and natural plants and to explore the potentials of a plant-robot society able to produce architectural artifacts and living spaces. These robot-plant bio-hybrids create synergies that allow for new functions of plants and robots. They also create novel design opportunities for an architecture that fuses the design and construction phase. The bio-hybrid is an example of mixed societies between 'hard' artificial and 'wet' natural life, which enables an interaction between natural and artificial ecologies. They form an embodied, self-organizing, and distributed cognitive system which is supposed to grow and develop over long periods of time resulting in the creation of meaningful architectural structures. A key idea is to assign equal roles to robots and plants in order to create a highly integrated, symbiotic system. Besides the gain of knowledge, this project has the objective to create a bio-hybrid system with a defined function and application -- growing architectural artifacts.},
author = {Hamann, Heiko and Wahby, Mostafa and Schmickl, Thomas and Zahadat, Payam and Hofstadler, Daniel and Stoy, Kasper and Risi, Sebastian and Faina, Andres and Veenstra, Frank and Kernbach, Serge and Kuksin, Igor and Kernbach, Olga and Ayres, Phil and Wojtaszek, Przemyslaw},
booktitle = {Proceedings of the 2015 IEEE Symposium on Artificial Life (IEEE ALIFE'15)},
isbn = {9781479975600},
title = {{Flora Robotica - Mixed Societies of Symbiotic Robot-Plant Bio-Hybrids}},
doi = {10.1109/ssci.2015.158},
year = {2015},
}
@inbook{19989,
author = {Hamann, Heiko and Correll, Nikolaus and Kacprzyk, Janusz and Pedrycz, Witold},
booktitle = {Springer Handbook of Computational Intelligence},
pages = {1423--1431},
publisher = {Springer},
title = {{Probabilistic Modeling of Swarming Systems}},
doi = {10.1007/978-3-662-43505-2_74},
year = {2015},
}
@inproceedings{19991,
author = {Hamann, Heiko and Schmickl, Thomas and Kengyel, Daniela and Zahadat, Payam and Radspieler, Gerald and Wotawa, Franz},
booktitle = {Principles and Practice of Multi-Agent Systems (PRIMA 2015)},
pages = {201--217},
title = {{Potential of Heterogeneity in Collective Behaviors: A Case Study on Heterogeneous Swarms}},
year = {2015},
}
@inproceedings{20006,
author = {Dorigo, Marco and Hamann, Heiko and Valentini, Gabriele},
booktitle = {AAAI-15 Video Proceedings},
title = {{Self-organized collective decisions in a robot swarm}},
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},
}
@inproceedings{271,
abstract = {In \emph{bandwidth allocation games} (BAGs), the strategy of a player consists of various demands on different resources. The player's utility is at most the sum of these demands, provided they are fully satisfied. Every resource has a limited capacity and if it is exceeded by the total demand, it has to be split between the players. Since these games generally do not have pure Nash equilibria, we consider approximate pure Nash equilibria, in which no player can improve her utility by more than some fixed factor $\alpha$ through unilateral strategy changes. There is a threshold $\alpha_\delta$ (where $\delta$ is a parameter that limits the demand of each player on a specific resource) such that $\alpha$-approximate pure Nash equilibria always exist for $\alpha \geq \alpha_\delta$, but not for $\alpha < \alpha_\delta$. We give both upper and lower bounds on this threshold $\alpha_\delta$ and show that the corresponding decision problem is ${\sf NP}$-hard. We also show that the $\alpha$-approximate price of anarchy for BAGs is $\alpha+1$. For a restricted version of the game, where demands of players only differ slightly from each other (e.g. symmetric games), we show that approximate Nash equilibria can be reached (and thus also be computed) in polynomial time using the best-response dynamic. Finally, we show that a broader class of utility-maximization games (which includes BAGs) converges quickly towards states whose social welfare is close to the optimum.},
author = {Drees, Maximilian and Feldotto, Matthias and Riechers, Sören and Skopalik, Alexander},
booktitle = {Proceedings of the 8th International Symposium on Algorithmic Game Theory (SAGT)},
pages = {178--189},
title = {{On Existence and Properties of Approximate Pure Nash Equilibria in Bandwidth Allocation Games}},
doi = {10.1007/978-3-662-48433-3_14},
year = {2015},
}
@inproceedings{19959,
author = {Wahby, Mostafa and Hamann, Heiko},
booktitle = {Applications of Evolutionary Computation (EvoApplications 2015)},
title = {{On the Tradeoff between Hardware Protection and Optimization Success: A Case Study in Onboard Evolutionary Robotics for Autonomous Parallel Parking}},
doi = {10.1007/978-3-319-16549-3_61},
year = {2015},
}
@inproceedings{19966,
abstract = {Aggregation is a crucial task in swarm robotics to ensure cooperation. We investigate the task of aggregation on an area specified indirectly by certain environmental features, here it is a light distribution. We extend the original BEECLUST algorithm, that implements an aggregation behavior, to an adaptive variant that automatically adapts to any light conditions. We compare these two control algorithms in a number of swarm robot experiments with different light conditions. The improved, adaptive variant is found to be significantly better in the tested setup.},
author = {Wahby, Mostafa and Weinhold, Alexander and Hamann, Heiko},
booktitle = {Proceedings of the 9th EAI International Conference on Bio-inspired Information and Communications Technologies (formerly BIONETICS)},
isbn = {9781631901003},
title = {{Revisiting BEECLUST: Aggregation of Swarm Robots with Adaptiveness to Different Light Settings}},
doi = {10.4108/eai.3-12-2015.2262877},
year = {2015},
}
@inproceedings{19980,
abstract = {Fitness function design is known to be a critical feature of the evolutionary-robotics approach. Potentially, the complexity of evolving a successful controller for a given task can be reduced by integrating a priori knowledge into the fitness function which complicates the comparability of studies in evolutionary robotics. Still, there are only few publications that study the actual effects of different fitness functions on the robot's performance. In this paper, we follow the fitness function classification of Nelson et al. (2009) and investigate a selection of four classes of fitness functions that require different degrees of a priori knowledge. The robot controllers are evolved in simulation using NEAT and we investigate different tasks including obstacle avoidance and (periodic) goal homing. The best evolved controllers were then post-evaluated by examining their potential for adaptation, determining their convergence rates, and using cross-comparisons based on the different fitness function classes. The results confirm that the integration of more a priori knowledge can simplify a task and show that more attention should be paid to fitness function classes when comparing different studies.},
author = {Hamann, Heiko and Divband Soorati, Mohammad},
booktitle = {Proceedings of the Genetic and Evolutionary Computation Conference (GECCO 2015)},
pages = {153--160},
publisher = {ACM},
title = {{The Effect of Fitness Function Design on Performance in Evolutionary Robotics: The Influence of a Priori Knowledge}},
doi = {10.1145/2739480.2754676},
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},
}
@article{19992,
author = {Valentini, Gabriele and Hamann, Heiko},
issn = {1935-3812},
journal = {Swarm Intelligence},
pages = {153--176},
title = {{Time-variant feedback processes in collective decision-making systems: influence and effect of dynamic neighborhood sizes}},
doi = {10.1007/s11721-015-0108-8},
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},
}
@misc{316,
author = {Pautz, Jannis},
publisher = {Universität Paderborn},
title = {{Budget Games with priced strategies}},
year = {2015},
}
@misc{277,
author = {Kothe, Nils},
publisher = {Universität Paderborn},
title = {{Multilevel Netzwerk Spiele mit konstanten Entfernungen im Highspeed-Netzwerk}},
year = {2015},
}
@article{19962,
abstract = {Recent approaches in evolutionary robotics (ER) propose to generate behavioral diversity in order to evolve desired behaviors more easily. These approaches require the definition of a behavioral distance, which often includes task-specific features and hence a priori knowledge. Alternative methods, which do not explicitly force selective pressure towards diversity (SPTD) but still generate it, are known from the field of artificial life, such as in artificial ecologies (AEs). In this study, we investigate how SPTD is generated without task-specific behavioral features or other forms of a priori knowledge and detect how methods of generating SPTD can be transferred from the domain of AE to ER. A promising finding is that in both types of systems, in systems from ER that generate behavioral diversity and also in the investigated speciation model, selective pressure is generated towards unpopulated regions of search space. In a simple case study we investigate the practical implications of these findings and point to options for transferring the idea of self-organizing SPTD in AEs to the domain of ER.},
author = {Hamann, Heiko},
issn = {1064-5462},
journal = {Artificial Life},
pages = {464--480},
title = {{Lessons from Speciation Dynamics: How to Generate Selective Pressure Towards Diversity}},
doi = {10.1162/artl_a_00186},
year = {2015},
}
@inproceedings{19967,
author = {Wahby, Mostafa and Divband Soorati, Mohammad and von Mammen, Sebastian and Hamann, Heiko},
booktitle = {Proceedings. 25. Computational Intelligence Workshop},
title = {{Evolution of Controllers for Robot-Plant Bio-Hybdrids: A Simple Case Study Using a Model of Plant Growth and Motion}},
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},
}
@phdthesis{317,
author = {Jähn, Claudius},
publisher = {Universität Paderborn},
title = {{Bewertung von Renderingalgorithmen für komplexe 3-D-Szenen}},
year = {2015},
}