@article{19726, abstract = {{The Paderborn University BSP (PUB) library is a C communication library based on the BSP model. The basic library supports buffered as well as unbuffered non-blocking communication between any pair of processors and a mechanism for synchronizing the processors in a barrier style. In addition, PUB provides non-blocking collective communication operations on arbitrary subsets of processors, the ability to partition the processors into independent groups that execute asynchronously from each other, and a zero-cost synchronization mechanism. Furthermore, some techniques used in the implementation of the PUB library deviate significantly from the techniques used in other BSP libraries.}}, author = {{Bonorden, Olaf and Juurlink, Bernhardus and von Otte, Ingo and Rieping, Ingo}}, issn = {{0167-8191}}, journal = {{Parallel Computing}}, pages = {{187--207}}, title = {{{The Paderborn University BSP (PUB) library}}}, doi = {{10.1016/s0167-8191(02)00218-1}}, year = {{2003}}, } @article{19785, author = {{Salzwedel, Kay A.}}, isbn = {{9783540008835}}, issn = {{0302-9743}}, journal = {{Algorithms for Memory Hierarchies}}, title = {{{Algorithmic Approaches for Storage Networks}}}, doi = {{10.1007/3-540-36574-5_12}}, volume = {{2625}}, year = {{2003}}, } @inproceedings{19790, abstract = {{The advances in Internet technology have led to tremendous improvements in business, education, and science and have changed the way we think, live, and communicate. Information exchange has become ubiquitous by the possibilities offered through modern technologies. We are able to offer information 24 hours a day through our web sites and can leave messages every time and from anywhere in the world. This change in communication has led to new challenges. Enterprises have to deal with an information amount that doubles every year. The technological foundation to cope with this information explosion is given by Storage Area Networks (SANs), which are able to connect a great number of storage systems over a fast interconnection network. However, to be able to use the benefits of a SAN, an easy-to-use and efficient management support has to be given to the storage administrator. In this paper, we will suggest new storage management concepts and we will introduce a new management environment that is able to significantly reduce management costs and increases the performance and resource utilization of the given SAN infrastructure.}}, author = {{Scheideler, Christian and Salzwedel, Kay and Meyer auf der Heide, Friedhelm and Brinkmann, André and Vodisek, Mario and Rückert, Ulrich}}, booktitle = {{Proceedings of SSGRR 2003}}, title = {{{Storage Management as Means to cope with Exponential Information Growth}}}, year = {{2003}}, } @inproceedings{19806, abstract = {{We try to close the gap between theoretical investigations of wireless network topologies and realistic wireless environments. For point-to-point communication, we examine theoretically well-analyzed sparse graphs, i.e. the Yao-graph, the SparsY-graph, and the SymmY-graph. We present distributed algorithms that can be used to build up these graphs in time $O(log n)$ per node without the use of any geo-graphical positioning system. Our algorithms are based only on local knowledge and local decisions and make use of power control to establish communication links with low energy-cost. We compare these algorithms with respect to congestion, dilation, and energy. For congestion we introduce different measures that allow us to investigate the difference between real-world wireless networks and models for wireless communication at a high level of abstraction. For more realistic simulations we extend our simulation environment SAHNE. We use a realistic transmission model for directed communication that uses sector subdivision. Finally, our experimental results show that our topologies and algorithms work well in a distributed environment and we give some recommendations for the topology control based on our simulations.}}, author = {{Rührup, Stefan and Schindelhauer, Christian and Volbert, Klaus and Grünewald, M.}}, booktitle = {{Proceedings of the International Parallel and Distributed Processing Symposium (IPDPS)}}, isbn = {{0769519261}}, title = {{{Performance of distributed algorithms for topology control in wireless networks}}}, doi = {{10.1109/ipdps.2003.1213107}}, year = {{2003}}, } @misc{19828, author = {{Mahlmann, Peter}}, title = {{{Implementierung und Vergleich von Verfahren zum Information Retrieval im World Wide Web}}}, year = {{2003}}, } @inproceedings{19833, abstract = {{Communication facilities are important in Robotics if several robots have to work together. In this paper, we describe problems and solutions encountered while designing an infrared-based communication device for the mini robot Khepera. In contrast to traditional omnidirectional systems, it features directed, power-variable transmission in eight directions at unit[23.4]kbps up to a range of unit[1m]. It can differentiate incoming data signals from interference from adjacent sectors and can estimate their direction-of-arrival. We model the transmission over the infrared channel and show how interference influences the reception of the data signals. We also describe methods how to reduce these effects. We have tested the performance of the resulted signal processing in a worst case scenario by simulations and in experiments with a prototype implementation. The resulted module is especially suited for experimental evaluation of ad hoc network protocols and for position estimation.}}, author = {{Volbert, Klaus and Grünewald, Matthias and Schindelhauer, Christian and Rückert, Ulrich}}, booktitle = {{Proceedings of the 2nd International Conference on Autonomous Minirobots for Research and Edutainment}}, pages = {{113--122}}, title = {{{Directed power-variable infrared communication for the mini robot Khepera}}}, year = {{2003}}, } @inproceedings{19874, abstract = {{We present a novel framework for hierarchical collision detection that can be applied to virtually all bounding volume (BV) hierarchies. It allows an application to trade quality for speed. Our algorithm yields an estimation of the quality, so that applications can specify the desired quality. In a timecritical system, applications can specify the maximum time budget instead, and quantitatively assess the quality of the results returned by the collision detection afterwards.}}, author = {{Klein, Jan and Zachmann, Gabriel}}, booktitle = {{Proc. 8th International Fall Workshop Vision, Modeling, and Visualization (VMV 2003)}}, pages = {{37--45}}, title = {{{ADB-Trees: Controlling the Error of Time-Critical Collision Detection}}}, year = {{2003}}, } @inproceedings{19900, author = {{Klein, Jan and Zachmann, Gabriel}}, booktitle = {{ Proc. ACM Symposium on Virtual Reality Software and Technology (VRST 2003)}}, pages = {{22--31}}, title = {{{Time-Critical Collision Detection Using an Average-Case Approach}}}, doi = {{10.1145/1008653.1008660}}, year = {{2003}}, } @inproceedings{19952, abstract = {{Graph minors theory, developed by Robertson & Seymour, provides a list of powerful theoretical results and tools. However, the wide spread opinion in Graph Algorithms community about this theory is that it is mainly of theoretical importance. The main purpose of this paper is to show how very deep min-max and duality theorems from Graph Minors can be used to obtain essential speed-up to many known algorithms on different domination problems.}}, author = {{Fomin, Fedor V. and Thilikos, Dimitrios M.}}, booktitle = {{Proceedings of the 14th ACM-SIAM Symposium on Discrete Algorithms (SODA 2003)}}, issn = {{0097-5397}}, title = {{{Dominating Sets in Planar Graphs: Branch-Width and Exponential Speed-Up}}}, doi = {{10.1137/s0097539702419649}}, year = {{2003}}, } @inproceedings{24273, author = {{Terbahl, Martina and Krokowski, Jens}}, booktitle = {{Proceedings of 5. GI-Informatiktage 2003}}, title = {{{Verteiltes Rendern durch dynamische Bildaufteilung}}}, year = {{2003}}, } @inproceedings{26263, author = {{Ziegler, Martin}}, booktitle = {{Proc. 5th Conference on Real Numbers and Computers (RNC5), INRIA}}, pages = {{47--64}}, title = {{{Stability versus Speed in a Computable Algebraic Model}}}, year = {{2003}}, } @inproceedings{26277, author = {{Ziegler, Martin}}, booktitle = {{Computability and Complexity in Analysis}}, pages = {{389--406}}, title = {{{Computable Operators on Regular Sets}}}, volume = {{302-8/2003}}, year = {{2003}}, } @inproceedings{2128, author = {{Damerow, Valentina and Meyer auf der Heide, Friedhelm and Räcke, Harald and Scheideler, Christian and Sohler, Christian}}, booktitle = {{ESA}}, pages = {{161----171}}, publisher = {{Springer}}, title = {{{Smoothed Motion Complexity}}}, doi = {{10.1007/978-3-540-39658-1_17}}, volume = {{2832}}, year = {{2003}}, } @inproceedings{2129, author = {{Awerbuch, Baruch and Brinkmann, André and Scheideler, Christian}}, booktitle = {{ICALP}}, pages = {{1153----1168}}, publisher = {{Springer}}, title = {{{Anycasting in Adversarial Systems: Routing and Admission Control}}}, volume = {{2719}}, year = {{2003}}, } @inproceedings{17423, author = {{Mueck, Bengt and Dangelmaier, Wilhelm and Fischer, Matthias}}, booktitle = {{15th European Simulation Symposium (ESS 2003)}}, pages = {{367--371}}, publisher = {{SCS - Europe}}, title = {{{Components for the Active Support of the Analysis of Material Flow Simulations in a Virtual Environment}}}, year = {{2003}}, } @inproceedings{18791, abstract = {{We consider the problem of finding the weight of a Euclidean minimum spanning tree for a set of n points in ℝd. We focus on the situation when the input point set is supported by certain basic (and commonly used) geometric data structures that can provide efficient access to the input in a structured way. We present an algorithm that estimates with high probability the weight of a Euclidean minimum spanning tree of a set of points to within 1 + ε using only \~{O}(√ poly(1/ε)) queries for constant d. The algorithm assumes that the input is supported by a minimal bounding cube enclosing it, by orthogonal range queries, and by cone approximate nearest neighbors queries.}}, author = {{Magen, Avner and Ergun, Funda and Sohler, Christian and Rubinfeld, Ronitt and Czumaj, Artur and Newman, Ilan and Fortnow, Lance}}, booktitle = {{Proceedings of the 14th ACM-SIAM Symposium on Discrete Algorithms (SODA 2003)}}, isbn = {{0898715385}}, pages = {{813–822}}, title = {{{Sublinear Approximation of Euclidean Minimum Spanning Tree}}}, year = {{2003}}, } @inproceedings{18907, abstract = {{In a (randomized) oblivious routing scheme the path chosen for a request
between a source $s$ and a target $t$ is independent from the current traffic
in the network. Hence, such a scheme consists of probability distributions
over $s-t$ paths for every source-target pair $s,t$ in the network.

In a recent result citeR02 it was shown that for any undirected network
there is an oblivious routing scheme that achieves a polylogarithmic
competitive ratio with respect to congestion. Subsequently, Azar et
al. citeACF+03 gave a polynomial time algorithm that for a given network
constructs the best oblivious routing scheme, i.e. the scheme that guarantees
the best possible competitive ratio.
Unfortunately, the latter result is based on the Ellipsoid algorithm; hence
it is unpractical for large networks.

In this paper we present a combinatorial algorithm for constructing an
oblivious routing scheme that guarantees a competitive ratio of $O(log^4n)$
for undirected networks. Furthermore, our approach yields a proof
for the existence of an oblivious routing scheme with competitive ratio
$O(log^3n)$, which is much simpler than the original proof from citeR02.}}, author = {{Bienkowski, Marcin and Korzeniowski, Miroslaw and Räcke, Harald}}, booktitle = {{Proceedings of the fifteenth annual ACM symposium on Parallel algorithms and architectures - SPAA '03}}, isbn = {{1581136617}}, title = {{{A practical algorithm for constructing oblivious routing schemes}}}, doi = {{10.1145/777412.777418}}, year = {{2003}}, } @inproceedings{18947, abstract = {{In this paper, we define a Petri net model for the network or routing layer of a mobile ad hoc network. Such networks require routing strategies substantially different from those used in static communication networks. The model pre- sented consists of two layers, a location service and a po- sition based routing. Both are described in detail. Our ap- proach considers a very strong definition of fault tolerance thereby improving state-of-the-art ad hoc routing protocols in several respects. Modeling of the communication archi- tecture for mobile ad hoc networks is part of our overall effort towards a design methodology for distributed embed- ded real-time systems including dynamically evolving com- ponents.}}, author = {{Rust, Carsten and Stappert, Friedhelm and Lukovszki, Tamás}}, booktitle = {{7th World Multiconference on Systemics, Cybernetics and Informatics}}, title = {{{A Petri Net Model for the Network Layer of a Mobile Ad Hoc Network Architecture}}}, year = {{2003}}, } @inproceedings{18960, abstract = {{We investigate distributed algorithms for mobile ad hoc networks for moving radio stations with adjustable transmission power in a worst case scenario. We consider two models to find a reasonable restriction on the worst-case mobility. In the pedestrian model we assume a maximum speed $v_max$ of the radio stations, while in the vehicular model we assume a maximum acceleration $a_max$ of the points. Our goal is to maintain persistent routes with nice communication network properties like hop-distance, energy-consumption, congestion and number of interferences. A route is persistent, if we can guarantee that all edges of this route can be uphold for a given time span $Delta$, which is a parameter denoting the minimum time the mobile network needs to adopt changes, i.e. update routing tables, change directory entries, etc. This $Delta$ can be used as the length of an update interval for a proactive routing scheme. We extend some known notions such as transmission range, interferences, spanner, power spanner and congestion to both mobility models and introduce a new parameter called crowdedness that states a lower bound on the number of radio interferences. Then we prove that a mobile spanner hosts a path system that polylogarithmically approximates the optimal congestion. We present distributed algorithms based on a grid clustering technique and a high-dimensional representation of the dynamical start situation which construct mobile spanners with low congestion, low interference number, low energy-consumption, and low degree. We measure the optimality of the output of our algorithm by comparing it with the optimal choice of persistent routes under the same circumstances with respect to pedestrian or vehicular worst-case movements. Finally, we present solutions for dynamic position information management under our mobility models.}}, author = {{Schindelhauer, Christian and Lukovszki, Tamás and Rührup, Stefan and Volbert, Klaus}}, booktitle = {{Proc. of the 15th ACM Symposium on Parallel Algorithms and Architectures (SPAA03)}}, isbn = {{1581136617}}, title = {{{Worst case mobility in ad hoc networks}}}, doi = {{10.1145/777412.777448}}, year = {{2003}}, } @inproceedings{18966, abstract = {{A recent seminal result of Räcke is that for any undirected network there is an oblivious routing algorithm with a polylogarithmic competitive ratio with respect to congestion. Unfortunately, Räcke's construction is not polynomial time. We give a polynomial time construction that guarantees Räcke's bounds, and more generally gives the true optimal ratio for any (undirected or directed) network.}}, author = {{Azar, Yossi and Cohen, Edith and Fiat, Amos and Kaplan, Haim and Racke, Harald}}, booktitle = {{Proceedings of the thirty-fifth ACM symposium on Theory of computing - STOC '03}}, isbn = {{1581136749}}, title = {{{Optimal oblivious routing in polynomial time}}}, doi = {{10.1145/780542.780599}}, year = {{2003}}, }