Publikationen:

Gehweiler, Joachim; Kling, Peter; Meyer auf der Heide, Friedhelm: An Experimental Comparison of Load Balancing Strategies in a Web Computing Environment. In: Wyrzykowski, Roman (Hrsg.) Proceedings of the 9th International Conference on Parallel Processing and Applied Mathematics, LNCS, 2011

Abshoff, Sebastian; Cord-Landwehr, Andreas; Degener, Bastian; Kempkes, Barbara; Pietrzyk, Peter: Local Approximation Algorithms for the Uncapacitated Metric Facility Location Problem in Power-Aware Sensor Networks. In: Proceedings of 7th International Symposium on Algorithms for Sensor Systems, Wireless Ad Hoc Networks and Autonomous Mobile Entities, LNCS, 2011

Cord-Landwehr, Andreas; Degener, Bastian; Fischer, Matthias; Hüllmann, Martina; Kempkes, Barbara; Klaas, Alexander; Kling, Peter; Kurras, Sven; Märtens, Marcus; Meyer auf der Heide, Friedhelm; Raupach, Christoph; Swierkot, Kamil; Warner, Daniel; Weddemann, Christoph; Wonisch, Daniel: A new Approach for Analyzing Convergence Algorithms for Mobile Robots. In: Proceedings of the 38th International Colloquium on Automata, Languages and Programming (ICALP 2011), LNCS, volume 6756, pp. 650--661, 2011

Kling, Peter; Meyer auf der Heide, Friedhelm: Convergence of Local Communication Chain Strategies via Linear Transformations. In: Proceedings of the 23rd ACM Symposium on Parallelism in Algorithms and Architectures (SPAA), pp. 159--166, 2011

Eikel, Benjamin; Jähn, Claudius; Petring, Ralf: PADrend: Platform for Algorithm Development and Rendering. In: Gausemeier, Jürgen; Grafe, Michael; Meyer auf der Heide, Friedhelm (Hrsg.) Augmented & Virtual Reality in der Produktentstehung, HNI-Verlagsschriftenreihe, Band 295, pp. 159--170, Heinz Nixdorf Institut, Universität Paderborn, 2011

Süß, Tim; Koch, Clemens; Jähn, Claudius; Fischer, Matthias: Approximative occlusion culling using the hull tree. In: Proceedings of Graphics Interface 2011, pp. 79--86, Canadian Human-Computer Communications Society, 2011

Süß, Tim; Jähn, Claudius; Fischer, Matthias; Meyer auf der Heide, Friedhelm; Koch, Clemens: Ein paralleles Out-of-Core Renderingsystem für Standard-Rechnernetze. In: Gausemeier, Jürgen; Grafe, Michael; Meyer auf der Heide, Friedhelm (Hrsg.) Augmented & Virtual Reality in der Produktentstehung, HNI-Verlagsschriftenreihe, Band 295, S. 185--197, Heinz Nixdorf Institut, Universität Paderborn, 2011

Degener, Bastian; Fekete, Sándor; Kempkes, Barbara; Meyer auf der Heide, Friedhelm: A survey on relay placement with runtime and approximation guarantees. Computer Science Review, 5(1): pp. 57-68, 2011

Cord-Landwehr, Andreas; Degener, Bastian; Fischer, Matthias; Hüllmann, Martina; Kempkes, Barbara; Klaas, Alexander; Kling, Peter; Kurras, Sven; Märtens, Marcus; Meyer auf der Heide, Friedhelm; Raupach, Christoph; Swierkot, Kamil; Warner, Daniel; Weddemann, Christoph; Wonisch, Daniel: Collisionless Gathering of Robots with an Extent. In: 37th International Conference on Current Trends in Theory and Practice of Computer Science (SOFSEM 2011), LNCS, volume 6543, pp. 178-189, 2011

Schumacher, Tobias; Süß, Tim; Plessl, Christian; Platzner, Marco: FPGA Acceleration of Communication-Bound Streaming Applications: Architecture Modeling and a 3D Image Compositing Case Study. International Journal of Reconfigurable Computing, pp. 1--11, 2011

Renken, Hendrik; Laroque, Christoph; Fischer, Matthias: An Easy Extendable Modeling Framework for Discrete Event Simulation Models and their Visualization. In: Proceedings of The 25th European Simulation and Modelling Conference - (ESM'11), 2011

Degener, Bastian; Kempkes, Barbara; Langner, Tobias; Meyer auf der Heide, Friedhelm; Wattenhofer, Roger: A tight runtime bound for synchronous gathering of autonomous robots with limited visibility. In: Proceedings of the 23rd annual ACM symposium on parallel algorithms and architectures (SPAA'11), pp. 139-147, 2011

Klaas, Alexander; Laroque, Christoph; Fischer, Matthias; Dangelmaier, Wilhelm: Simulation Aided, Knowledge Based Routing for AGVs in a Distribution Warehouse. In: Proceedings of the 2011 Winter Simulation Conference, 2011

Brandes, Philipp; Degener, Bastian; Kempkes, Barbara; Meyer auf der Heide, Friedhelm: Energy-efficient strategies for building short chains of mobile robots locally. In: Proceedings of the 18th International Colloquium on Structural Information and Communication Complexity (SIROCCO'11), pp. 138-149, 2011

Briest, Patrick; Raupach, Christoph: The Car Sharing Problem. In: Proceedings of the 23rd ACM Symposium on Parallelism in Algorithms and Architectures (SPAA'11), 2011

Briest, Patrick; Hoefer, Martin; Krysta, Piotr: Stackelberg Network Pricing Games. Algorithmica, 2011

Degener, Bastian; Kempkes, Barbara; Meyer auf der Heide, Friedhelm: Organic Computing — A Paradigm Shift for Complex Systems, Autonomic Systems, volume 1, chapter Energy-Awareness in Self-organising Robotic Exploration Teams, pp. 531-543, Springer Verlag, 2011

Briest, Patrick; Krysta, Piotr: Buying Cheap is Expensive: Approximability of Combinatorial Pricing Problems. SIAM Journal on Computing, 2011

Klaas, Alexander; Laroque, Christoph; Renken, Hendrik; Dangelmaier, Wilhelm: Goal-Based Agents in Material Flow Simulations - Integration of an Agent Programming Framework in the Discrete Event Simulator D3FACT. In: Proceedings of The 25th European Simulation and Modelling Conference (ESM'11), 2011

Briest, Patrick; Krysta, Piotr; Vöcking, Berthold: Approximation Techniques for Utilitarian Mechanism Design. SIAM Journal on Computing, 2011

Promotionen

Joachim Gehweiler:
Peer-to-Peer Based Parallel Web Computing
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. In this thesis we consider a web computing variant with two important properties: First, we support the execution of coupled, massively parallel algorithms (rather than distributed data processing). And second, we organize the system in peer-to-peer fashion.We present the Paderborn University BSP-based Web Computing (PUB-Web) library, which supports the execution of parallel programs in the bulk-synchronous style (BSP) in such a web computing setting. In this thesis, we focus on important technical and algorithmic aspects, in particular: In order to schedule processes with respect to the currently available computing power, which continually changes in an unpredictable fashion, we need intelligent load balancing algorithms and as a basic precondition the technical ability to migrate threads at runtime.To achieve the latter, we present the PadMig thread migration and checkpointing library. In order to tackle the distributed load balancing problem, we present an algorithm based on Distributed Heterogeneous Hash-Tables. In order to judge the quality of the schedules produced, we perform extensive experiments. Beside the available computing power, we finally also consider the network bandwidth as a secondary criterion for load balancing.

Sascha Effert:
Verfahren zur redundanten Datenplatzierung in skalierbaren Speichersystemen
Moderne Datenzentren sind mit einer rasant wachsenden Menge an Daten konfrontiert, welche sie mit immer höherer Geschwindigkeit hochverfügbar speichern müssen. Daher brauchen sie Speichersysteme, welche mit ihren Anforderungen wachsen. Zunehmend werden dazu Speichernetze eingesetzt, in welchen Datenserver einen virtuellen Speicher über Festplatten erzeugen. Dabei ist die Last des virtuellen Speichers so zu verteilen, dass die physikalischen Festplatten optimal genutzt werden. Um Ausfälle kompensieren zu können ist es nötig, Daten redundant zu speichern. Die Verfahren zur Datenverteilung müssen diesen Anforderungen gerecht werden. Einen wichtigen Beitrag liefern hier pseudorandomisierte Hashfunktionen. Innerhalb dieser Arbeit gehe ich auf verschiedene Speichersysteme ein. Speziell untersuche ich Speichernetze, welche aus Datenservern mit lokalen Festplatten bestehen. Für diese zeige ich, wie sie bei verschiedenen Arten der Datenverteilung skalieren. Leider wird keines der betrachteten Speichersysteme allen Anforderungen gerecht. Als Lösung stelle ich das Verfahren Redundant Share vor, welches alle Anforderungen erfüllt. Mittels Redundant Share kann eine beliebige Anzahl an Kopien der Daten des virtuellen Speichers wie gefordert verteilt werden. Gleichzeitig erfordert das Hinzufügen neuer Festplatten einen begrenzten Aufwand. Abschließend vermesse ich eine Implementierung von Redundant Share und vergleiche die Ergebnisse mit anderen Verteilern.

weitere Funktionen

Friedhelm Meyer auf der Heide:

Member of the “Hochschulrat“ of the University of Paderborn
Director of the Collaborative Research Center (SFB 901) “On-The-Fly Computing"
Member of the German Academy of Sciences “Leopoldina“
DFG Special Advisor (Vertrauensdozent) of the University of Paderborn
Member of the Board of External Scientific Advisers (Fachbeirat) of the Max-Planck-Institute for Computer Science at Saarbrücken
Direktor der NRW-Graduate School of Dynamic Intelligent Systems (one of three directors)
Assistant Chairman of the Paderborn Institute for Scientific Computation (PaSCo)
Managing Editor of “Journal of Interconnection Networks (JOIN)“, World Scientific Publishing
Member of the program committee of the workshop “Parallele Algorithmen, Rechnerstrukturen und Systemsoftware (PARS)“, 2011
Member of the Evaluation Committee of the Bundeswettbewerb “Jugend Forscht“, Coordinator of the section on Computer Science and Mathematics.
General Chair of the ACM-Symposium “Parallelism in Algorithms and Architectures (SPAA)“
Member of the Award Committee of the European Association for Theoretical Computer Science (EATCS)

Patrick Briest:

Member of the program committee of the "ACM Conference on Electronic Commerce (EC)", 2011.
Member of the program committee of the "International Symposium on Theoretical Aspects of Computer Science (STACS)", 2011.

Graduiertenprogramme:

International Graduate School: NRW Graduate School of Dynamic Intelligent Systems
GSANS - the Paderborn Graduate School on Applied Network Science
DFG Research Training Centre "Research Training Group Automatisms - Emerging structures in information technology, media, and culture"

Aktuelle Forschungsprojekte

DFG Collaborative Research Center 901:

„On-The-Fly Computing“ with the Subprojects A1 “Capabilities and limitations of local strategies in dynamic networks" (jointly with Prof. Dr. Christian Scheideler), C2 „On-The-Fly Compute Centers“ (jointly with Jun.-Prof. Dr.-Ing. André Brinkmann, Prof. Dr. Marco Platzner), and Z (Central Duties of the CRC)

FRONTS:

EU-Strep “Foundations of Adaptive Networked Societies of Tiny Artefacts“

DFG-SmartTeams:

DFG-Schwerpunktprogramm 1183 „Organic Computing“ mit dem Projekt: „Smart Teams“ (zusammen mit Prof. Dr. rer. nat. Christian Schindelhauer, Freiburg)

DFG-AVIPASIA:

DFG project “Interactive Model Modification, Synchronized Analysis and 3D Visualization of Parallel Discrete Event Simulation“ (with Prof. Dr.-Ing. habil. Wilhelm Dangelmaier and Dr. rer. nat. Matthias Fischer)