TY - CONF
AU - Wahby, Mostafa
AU - Divband Soorati, Mohammad
AU - von Mammen, Sebastian
AU - Hamann, Heiko
ID - 19967
T2 - Proceedings. 25. Computational Intelligence Workshop
TI - Evolution of Controllers for Robot-Plant Bio-Hybdrids: A Simple Case Study Using a Model of Plant Growth and Motion
ER -
TY - GEN
AB - 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.
AU - Abshoff, Sebastian
AU - Cord-Landwehr, Andreas
AU - Fischer, Matthias
AU - Jung, Daniel
AU - Meyer auf der Heide, Friedhelm
ID - 16449
T2 - arXiv:1510.05454
TI - Gathering a Closed Chain of Robots on a Grid
ER -
TY - GEN
AB - 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.
AU - Abu-Khzam, Faisal N.
AU - Markarian, Christine
AU - Meyer auf der Heide, Friedhelm
AU - Schubert, Michael
ID - 16452
T2 - arXiv:1510.01866
TI - Approximation and Heuristic Algorithms for Computing Backbones in Asymmetric Ad-Hoc Networks
ER -
TY - THES
AU - Jähn, Claudius
ID - 317
TI - Bewertung von Renderingalgorithmen für komplexe 3-D-Szenen
ER -
TY - CONF
AB - Many markets have seen a shift from the idea of buying and moved to leasing instead. Arguably, the latter has been the major catalyst for their success. Ten years ago, research realized this shift and initiated the study of "online leasing problems" by introducing leasing to online optimization problems. Resources required to provide a service in an "online leasing problem" are no more bought but leased for different durations. In this paper, we provide an overview of results that contribute to the understanding of "online resource leasing problems".
AU - Markarian, Christine
AU - Meyer auf der Heide, Friedhelm
ID - 266
T2 - Proceedings of the 2015 ACM Symposium on Principles of Distributed Computing (PODC)
TI - Online Resource Leasing
ER -
TY - BOOK
ED - Gausemeier, Jürgen
ED - Grafe, Michael
ED - Meyer auf der Heide, Friedhelm
ID - 17431
TI - Augmented & Virtual Reality in der Produktentstehung: Grundlagen, Methoden und Werkzeuge; Interaktions- und Visualisierungstechniken, Virtual Prototyping intelligenter technischer Systeme mit AR/VR
VL - 342
ER -
TY - JOUR
AB - 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.
AU - Cohen, R.
AU - Polevoy, Gleb
ID - 17657
IS - 99
JF - Cloud Computing, IEEE Transactions on
KW - Approximation algorithms
KW - Approximation methods
KW - Bandwidth
KW - Cloud computing
KW - Routing
KW - Schedules
KW - Scheduling
SN - 2168-7161
TI - Inter-Datacenter Scheduling of Large Data Flows
VL - PP
ER -
TY - CONF
AB - Consider the problem in which n jobs that are classified into k types are to be scheduled on m identical machines without preemption. A machine requires a proper setup taking s time units before processing jobs of a given type. The objective is to minimize the makespan of the resulting schedule. We design and analyze an approximation algorithm that runs in time polynomial in n,m and k and computes a solution with an approximation factor that can be made arbitrarily close to 3/2.
AU - Mäcker, Alexander
AU - Malatyali, Manuel
AU - Meyer auf der Heide, Friedhelm
AU - Riechers, Sören
ED - Dehne, Frank
ED - Sack, Jörg Rüdiger
ED - Stege, Ulrike
ID - 274
T2 - Algorithms and Data Structures: 14th International Symposium, WADS 2015, Victoria, BC, Canada, August 5-7, 2015. Proceedings
TI - Non-preemptive Scheduling on Machines with Setup Times
ER -
TY - THES
AU - Markarian, Christine
ID - 267
TI - Online Resource Leasing
ER -
TY - JOUR
AB - We consider structural and algorithmic questions related to the Nash dynamics of weighted congestion games. In weighted congestion games with linear latency functions, the existence of pure Nash equilibria is guaranteed by a potential function argument. Unfortunately, this proof of existence is inefficient and computing pure Nash equilibria in such games is a PLS-hard problem even when all players have unit weights. The situation gets worse when superlinear (e.g., quadratic) latency functions come into play; in this case, the Nash dynamics of the game may contain cycles and pure Nash equilibria may not even exist. Given these obstacles, we consider approximate pure Nash equilibria as alternative solution concepts. A ρ--approximate pure Nash equilibrium is a state of a (weighted congestion) game from which no player has any incentive to deviate in order to improve her cost by a multiplicative factor higher than ρ. Do such equilibria exist for small values of ρ? And if so, can we compute them efficiently?We provide positive answers to both questions for weighted congestion games with polynomial latency functions by exploiting an “approximation” of such games by a new class of potential games that we call Ψ-games. This allows us to show that these games have d!-approximate pure Nash equilibria, where d is the maximum degree of the latency functions. Our main technical contribution is an efficient algorithm for computing O(1)-approximate pure Nash equilibria when d is a constant. For games with linear latency functions, the approximation guarantee is 3+√5/2 + Oγ for arbitrarily small γ > 0; for latency functions with maximum degree d≥ 2, it is d2d+o(d). The running time is polynomial in the number of bits in the representation of the game and 1/γ. As a byproduct of our techniques, we also show the following interesting structural statement for weighted congestion games with polynomial latency functions of maximum degree d ≥ 2: polynomially-long sequences of best-response moves from any initial state to a dO(d2)-approximate pure Nash equilibrium exist and can be efficiently identified in such games as long as d is a constant.To the best of our knowledge, these are the first positive algorithmic results for approximate pure Nash equilibria in weighted congestion games. Our techniques significantly extend our recent work on unweighted congestion games through the use of Ψ-games. The concept of approximating nonpotential games by potential ones is interesting in itself and might have further applications.
AU - Caragiannis, Ioannis
AU - Fanelli, Angelo
AU - Gravin, Nick
AU - Skopalik, Alexander
ID - 320
IS - 1
JF - Transactions on Economics and Computation
TI - Approximate Pure Nash Equilibria in Weighted Congestion Games: Existence, Efficient Computation, and Structure
VL - 3
ER -
TY - CONF
AU - Berssenbrügge, Jan
AU - Wiederkehr, Olga
AU - Jähn, Claudius
AU - Fischer, Matthias
ID - 17425
T2 - 12. Paderborner Workshop Augmented & Virtual Reality in der Produktentstehung
TI - Anbindung des Virtuellen Prototypen an die Partialmodelle intelligenter technischer Systeme
VL - 343
ER -
TY - CONF
AB - 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.
AU - Mäcker, Alexander
AU - Malatyali, Manuel
AU - Meyer auf der Heide, Friedhelm
ID - 16460
T2 - Proceedings of the 29th International Parallel and Distributed Processing Symposium (IPDPS)
TI - Online Top-k-Position Monitoring of Distributed Data Streams
ER -
TY - CONF
AU - Hamann, Heiko
AU - Schmickl, Thomas
AU - Zahadat, Payam
ID - 19988
T2 - 13th European Conference on Artificial Life (ECAL 2015)
TI - Evolving Collective Behaviors With Diverse But Predictable Sensor States
ER -
TY - CONF
AU - Ding, Hongli
AU - Hamann, Heiko
ID - 19990
T2 - First International Symposium on Swarm Behavior and Bio-Inspired Robotics (SWARM 2015)
TI - Dependability in Swarm Robotics: Error Detection and Correction
ER -
TY - CONF
AU - Dorigo, Marco
AU - Hamann, Heiko
AU - Valentini, Gabriele
ID - 20005
T2 - Proceedings of the 14th Int. Conf. on Autonomous Agents and Multiagent Systems (AAMAS 2015)
TI - Efficient Decision-Making in a Self-Organizing Robot Swarm: On the Speed Versus Accuracy Trade-Off
ER -
TY - JOUR
AB - 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.
AU - Bar-Yehuda, Reuven
AU - Polevoy, Gleb
AU - Rawitz, Dror
ID - 17658
JF - Discrete Applied Mathematics
KW - Local ratio
SN - 0166-218X
TI - Bandwidth allocation in cellular networks with multiple interferences
VL - 194
ER -
TY - CONF
AB - 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.
AU - Feldotto, Matthias
AU - Gairing, Martin
AU - Skopalik, Alexander
ID - 453
T2 - Proceedings of the 10th International Conference on Web and Internet Economics (WINE)
TI - Bounding the Potential Function in Congestion Games and Approximate Pure Nash Equilibria
ER -
TY - CONF
AB - 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.
AU - Dorigo, Marco
AU - Hamann, Heiko
AU - Valentini, Gabriele
AU - Lomuscio, Alessio
AU - Scerri, Paul
AU - Bazzan, Ana
AU - Huhns, Michael
ID - 20121
T2 - Proceedings of the 13th Int. Conf. on Autonomous Agents and Multiagent Systems (AAMAS 2014)
TI - Self-Organized Collective Decision Making: The Weighted Voter Model
ER -
TY - CONF
AU - Hamann, Heiko
ID - 20126
T2 - Int. Conf. on Genetic and Evolutionary Computation (GECCO 2014)
TI - Evolving Prediction Machines: Collective Behaviors Based on Minimal Surprisal
ER -
TY - CONF
AU - King, Thomas C.
AU - Liu, Qingzhi
AU - Polevoy, Gleb
AU - de Weerdt, Mathijs
AU - Dignum, Virginia
AU - van Riemsdijk, M. Birna
AU - Warnier, Martijn
ID - 17661
KW - crowd-sensing
KW - crowdsourcing
KW - data aggregation
KW - game theory
KW - norms
KW - reciprocation
KW - self interested agents
KW - simulation
SN - 978-1-4503-2738-1
T2 - Proceedings of the 2014 International Conference on Autonomous Agents and Multi-agent Systems
TI - Request Driven Social Sensing
ER -