TY - CONF
AU - Li, Shouwei
AU - Meyer auf der Heide, Friedhelm
AU - Podlipyan, Pavel
ID - 16358
T2 - Algorithms for Sensor Systems, Proceedings of the 12th International Symposium on Algorithms and Experiments for Wireless Sensor Networks (ALGOSENSORS)
TI - The impact of the Gabriel subgraph of the visibility graph on the gathering of mobile autonomous robots
ER -
TY - CONF
AB - 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 O(n) in the fully synchronous 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 2x2- 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 L1-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 merged to be only one robot. The locality constraint is the significant challenging issue here, since robot move- ments 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 con- nectivity. In our model, robots can obtain a special state, which marks such a robot to be performing specific connec- tivity preserving movements in order to allow later merge operations of the swarm. Compared to the grid, for gath- ering in the Euclidean plane for the same robot and time model the best known upper bound is O(n^2).
AU - Cord-Landwehr, Andreas
AU - Fischer, Matthias
AU - Jung, Daniel
AU - Meyer auf der Heide, Friedhelm
ID - 16359
T2 - Proceedings of the 28th ACM Symposium on Parallelism in Algorithms and Architectures (SPAA)
TI - Asymptotically Optimal Gathering on a Grid
ER -
TY - CONF
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*2 subgrid. Our model is completely local (no global control, no global coordinates, no compass, no global communication or vision, ...). Each robot can only see its next constant number of left and right neighbors on the chain. This fixed constant is called the 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 FSYNC model. For this problem, we present a gathering algorithm which needs linear time. This result generalizes a result, 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 - 16360
T2 - Proceedings of the 30th International Parallel and Distributed Processing Symposium (IPDPS)
TI - Gathering a Closed Chain of Robots on a Grid
ER -
TY - CONF
AU - Macker, Alexander
AU - Malatyali, Manuel
AU - Meyer auf der Heide, Friedhelm
ID - 16364
SN - 9781509021406
T2 - 2016 IEEE International Parallel and Distributed Processing Symposium (IPDPS)
TI - On Competitive Algorithms for Approximations of Top-k-Position Monitoring of Distributed Streams
ER -
TY - CONF
AU - Klingler, Florian
AU - Dressler, Falko
AU - Sommer, Christoph
ID - 16386
SN - 9781467394116
T2 - 2015 IEEE Vehicular Networking Conference (VNC)
TI - IEEE 802.11p unicast considered harmful
ER -
TY - GEN
AB - 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 $\beta < s$
no finite competitiveness is possible, our main result is an
$O(\frac{c}{\varepsilon} + \frac{1}{\varepsilon^3})$-competitive online
algorithm for $\beta = (1+\varepsilon)s$ with $\frac{1}{s} \leq \varepsilon
\leq 1$, where $s$ and $c$ denotes the largest setup time and the cost ratio of
the machine-types, respectively. It is complemented by a lower bound of
$\Omega(\frac{c}{\varepsilon})$.
AU - Mäcker, Alexander
AU - Malatyali, Manuel
AU - Meyer auf der Heide, Friedhelm
AU - Riechers, Sören
ID - 16396
T2 - arXiv:1609.01184
TI - Cost-efficient Scheduling on Machines from the Cloud
ER -
TY - GEN
AU - Czech, Mike
ID - 164
TI - Predicting Rankings of Software Verification Tools Using Kernels for Structured Data
ER -
TY - THES
AU - Bause, Fabian
ID - 13860
TI - Ein ultraschallbasiertes inverses Messverfahren zur Charakterisierung viskoelastischer Materialparameter von Polymeren
ER -
TY - GEN
AU - Olfert, Sergei
AU - Henning, Bernd
ID - 13862
TI - Anwendungsm\"oglichkeiten der Schallfeldvisualisierung in der Ultraschallmesstechnik
ER -
TY - JOUR
AU - Olfert, Sergei
AU - Henning, Bernd
ID - 13863
IS - 4
JF - Technisches Messen
TI - Erweiterung des Raman-Nath-Modells zur Analyse von Schlierenabbildungen
VL - 83
ER -