@inproceedings{657,
abstract = {We present two distributed, constant factor approximation algorithms for the metric facility location problem. Both algorithms have been designed with a strong emphasis on applicability in the area of wireless sensor networks: in order to execute them, each sensor node only requires limited local knowledge and simple computations. Also, the algorithms can cope with measurement errors and take into account that communication costs between sensor nodes do not necessarily increase linearly with the distance, but can be represented by a polynomial. Since it cannot always be expected that sensor nodes execute algorithms in a synchronized way, our algorithms are executed in an asynchronous model (but they are still able to break symmetry that might occur when two neighboring nodes act at exactly the same time). Furthermore, they can deal with dynamic scenarios: if a node moves, the solution is updated and the update affects only nodes in the local neighborhood. Finally, the algorithms are robust in the sense that incorrect behavior of some nodes during some round will, in the end, still result in a good approximation. The first algorithm runs in expected O(log_{1+\epsilon} n) communication rounds and yields a \my^4(1+4\my^2(1+\epsilon)^{1/p})^p approximation, while the second has a running time of expected O(log^2_{1+\epsilon} n) communication rounds and an approximation factor of \my^4(1 + 2(1 + \epsilon)^{1/p})^p. Here, \epsilon > 0 is an arbitrarily small constant, p the exponent of the polynomial representing the communication costs, and \my the relative measurement error.},
author = {Abshoff, Sebastan and Cord-Landwehr, Andreas and Degener, Bastian and Kempkes, Barbara and Pietrzyk, Peter},
booktitle = {Proceedings of the 7th International Symposium on Algorithms for Sensor Systems, Wireless Ad Hoc Networks and Autonomous Mobile Entities (ALGOSENSORS)},
pages = {13--27},
title = {{Local Approximation Algorithms for the Uncapacitated Metric Facility Location Problem in Power-Aware Sensor Networks}},
doi = {10.1007/978-3-642-28209-6_3},
year = {2011},
}
@inproceedings{664,
abstract = {Web Computing is a variant of parallel computing where the idle times of PCs donated by worldwide distributed users are employed to execute parallel programs. The PUB-Web library developed by us supports this kind of usage of computing resources. A major problem for the efficient execution of such parallel programs is load balancing. In the Web Computing context, this problem becomes more difficult because of the dynamic behavior of the underlying "parallel computer": the set of available processors (donated PCs) as well as their availability (idle times) change over time in an unpredictable fashion.In this paper, we experimentally evaluate and compare load balancing algorithms in this scenario, namely a variant of the well-established Work Stealing algorithm and strategies based on a heterogeneous version of distributed hash-tables (DHHTs) introduced recently. In order to run a meaningful experimental evaluation, we employ, in addition to our Web Computing library PUB-Web, realistic data sets for the job input streams and for the dynamics of the availability of the resources.Our experimental evaluations suggest that Work Stealing is the better strategy if the number of processes ready to run matches the number of available processors. But a suitable variant of DHHTs outperforms Work Stealing if there are significantly more processes ready to run than available processors.},
author = {Gehweiler, Joachim and Kling, Peter and Meyer auf der Heide, Friedhelm},
booktitle = {Proceedings of the 9th International Conference on Parallel Processing and Applied Mathematics (PPAM)},
pages = {31----40},
title = {{An Experimental Comparison of Load Balancing Strategies in a Web Computing Environment}},
doi = {10.1007/978-3-642-31500-8_4},
year = {2011},
}
@inproceedings{6740,
author = {Böttcher, Stefan and Bokermann, Dennis and Hartel, Rita},
booktitle = {Advances in Databases - 28th British National Conference on Databases, BNCOD 28, Revised Selected Papers},
pages = {209--220},
publisher = {Springer Berlin/Heidelberg},
title = {{Computing Compressed XML Data from Relational Databases}},
volume = {7051},
year = {2011},
}
@inproceedings{6834,
author = {Bendfeld, Jörg and Krauter, Stefan},
booktitle = {Wissenschaftliche Verhandlungen 2011 der Deutschen Physikalischen Gesellschaft, Dresden, März 2011},
title = {{Hybrid measuring devices for evaluation of waves and currents}},
year = {2011},
}
@inproceedings{6889,
author = {Wendlandt, S. and Drobisch, A. and Tomow, D. and Friedrichs, M. and Krauter, Stefan and Grunow, Paul},
booktitle = {Proceedings of the ISES Solar Word Congress},
title = {{Operating principle of a shadowed c-Si solar cell in PV modules}},
year = {2011},
}
@article{7476,
author = {Kremer, H.-Hugo and Frehe, Petra},
journal = {Beilage Schule NRW},
number = {05/11},
pages = {4--8},
title = {{Individuelle Förderung - aber wie? Einblicke in das Innovationsprojekt InLab}},
year = {2011},
}
@article{7483,
author = {Kremer, H.-Hugo and Sandmann, D.},
journal = {bwp@ Berufs- und Wirtschaftspädagogik - online},
title = {{Kooperationsvorhaben berufliches Gymnasium und Bachelor Wirtschaftswissenschaften. Ein Paderborner Modellprojekt zur Berufs- und Studienorientierung}},
year = {2011},
}
@article{7495,
author = {Urbanski, Martin and Piegdon, Karoline A. and Meier, Cedrik and Kitzerow, Heinz S.},
issn = {0267-8292},
journal = {Liquid Crystals},
number = {4},
pages = {475--482},
publisher = {Informa UK Limited},
title = {{Investigations on the director field around microdisc resonators}},
doi = {10.1080/02678292.2011.552742},
volume = {38},
year = {2011},
}
@article{7604,
author = {Kremer, H.-Hugo and Tramm, T.},
journal = {bwp@ Berufs- und Wirtschaftspädagogik - online},
title = {{Berufliche Bildung 2011, Fachtagung 19}},
year = {2011},
}
@inproceedings{796,
author = {Azeem M. Khan, Rana and Karl, Holger},
booktitle = {Ad-hoc, Mobile, and Wireless Networks - 10th International Conference, ADHOC-NOW 2011, Paderborn, Germany, July 18-20, 2011. Proceedings},
pages = {145----149},
title = {{Multihop Performance of Cooperative Preamble Sampling MAC(CPS-MAC) in Wireless Sensor Networks}},
doi = {10.1007/978-3-642-22450-8_11},
year = {2011},
}