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Auflistung nach Autor:in "Nagel, Wolfgang E."

1 - 10 von 21
  • Editiertes Buch
  • Konferenzbeitrag
    Adaptive Cache Infrastructure: Supporting dynamic Program Changes following dynamic Program Behavior
    (9th workshop on parallel systems and algorithms – workshop of the GI/ITG special interest groups PARS and PARVA, 2008) Nowak, Fabian; Buchty, Rainer; Karl, Wolfgang
    Recent examinations of program behavior at run-time revealed distinct phases. Thus, it is evident that a framework for supporting hardware adaptation to phase behavior is needed. With the memory access behavior being most important and cache accesses being a very big subset of them, we herein propose an infrastructure for fitting cache accesses to a program’s requirements for a distinct phase.
  • Journal
    Big Data Competence Center ScaDS Dresden/Leipzig: Overview and selected research activities
    (Datenbank-Spektrum: Vol. 19, No. 1, 2019) Rahm, Erhard; Nagel, Wolfgang E.; Peukert, Eric; Jäkel, René; Gärtner, Fabian; Stadler, Peter F.; Wiegreffe, Daniel; Zeckzer, Dirk; Lehner, Wolfgang
  • Textdokument
    Challenges in Creating a Sustainable Generic Research Data Infrastructure
    (Softwaretechnik-Trends: Vol. 37, No. 2, 2017) Grunzke, Richard; Müller-Pfefferkorn, Ralph; Nagel, Wolfgang E.; Adolph, Tobias; Biardzki, Christoph; Frank, Anton; Bode, Arndt; Kazakova, Anastasia; Limani, Fidan; Latif, Atif; Busch, Anja; Borst, Timo; Tochtermann, Klaus; Neumann, Mathis; Sousa, Nelson Tavares de; Thomsen, Ingo; Hasselbring, Wilhelm; Tendel, Jakob; Bungartz, Hans-Joachim; Grimm, Christian
    Research data management is of the utmost importance in a world where research data is created with an ever increasing amount and rate and with a high variety across all scientific disciplines. This paper especially discusses software engineering challenges stemming from creating a long-living software system. It aims at providing a reference implementation for a federated research data infrastructure including interconnected individual repositories for communities and an overarching search based on metadata. The challenges involve a high variety of evolving requirements, the management and development of the distributed and federated infrastructure that are based on exist- ing components, the piloting within the use cases, the efficient training of users, and how to enable the future sustainable operation.
  • Zeitschriftenartikel
    Data Analytics
    (Informatik Spektrum: Vol. 42, No. 6, 2019) Nagel, Wolfgang E.; Ludwig, Thomas
  • Konferenzbeitrag
    A Generic Tool Supporting Cache Design and Optimisation on Shared Memory Systems
    (9th workshop on parallel systems and algorithms – workshop of the GI/ITG special interest groups PARS and PARVA, 2008) Schindewolf, Martin; Tao, Jie; Karl, Wolfgang; Cintra, Marcelo
    For multi-core architectures, improving the cache performance is crucial for the overall system performance. In contrast to the common approach to design caches with the best trade-off between performance and costs, this work favours an application specific cache design. Therefore, an analysis tool capable of exhibiting the reason of cache misses has been developed. The results of the analysis can be used by system developers to improve cache architectures or can help programmers to improve the data locality behaviour of their programs. The SPLASH-2 benchmark suite is used to demonstrate the abilities of the analysis model.
  • Konferenzbeitrag
    Grid Virtualization Engine: Providing Virtual Resources for Grid Infrastructure
    (9th workshop on parallel systems and algorithms – workshop of the GI/ITG special interest groups PARS and PARVA, 2008) Kwemou, Emeric; Wang, Lizhe; Tao, Jie; Kunze, Marcel; Kramer, David; Karl, Wolfgang
    Virtual machines offer a lot of advantage such as easy configuration and management and can simplify the development and the deployment of Grid infrastructures. Various virtualization implementations despite have similar functions often provide different management and access interfaces. The heterogeneous virtualization technologies bring challenges for employing virtual machine as computing resources to build Grid infrastructures. The work proposed in this paper focus on a Web service based virtual machine provider for Grid infrastructures. The Grid Virtualization Engine (GVE) creates an abstraction layer between users and underlying virtualization technologies. The GVE implements a scalable distributed architecture, where an GVE Agent represents a computing center. The Agent talks with different virtualization product inside the computing center and provides virtual machine resources to GVE Site Service. Users could require computing resources through GVE Site Services. The system is designed and implemented in the state of the arts of distributed computing: Web service and Grid standards.
  • Zeitschriftenartikel
    Grid-Computing
    (Informatik-Spektrum: Vol. 27, No. 6, 2004) Bry, François; Nagel, Wolfgang E.; Schroeder, Michael
    „Grid-Computing“, ein Mitte der 90er-Jahre eingeführter Begriff [1,2], bezeichnet eine Architektur für verteilte Systeme, die auf dem World Wide Web aufbaut und die Web-Vision erweitert. Mit dem Grid-Computing werden die Ressourcen einer Gemeinschaft, einer so genannten „virtuellen Organisation“, integriert. Die Hoffnung ist, dass hierdurch rechen- und/oder datenintensiven Aufgaben, die eine einzelne Organisation nicht lösen kann, handhabbar werden. Ein „Grid“ bezeichnet eine nach dem Grid-Computing-Ansatz aufgebaute Rechner-, Netzwerk- und Software-Infrastruktur zur Teilung von Ressourcen mit dem Ziel, die Aufgaben einer virtuellen Organisation zu erledigen.
  • Konferenzbeitrag
    High Performance Multigrid on Current Large Scale Parallel Computers
    (9th workshop on parallel systems and algorithms – workshop of the GI/ITG special interest groups PARS and PARVA, 2008) Gradl, Tobias; Rüde, Ulrich
    Making multigrid algorithms run efficiently on large parallel computers is a challenge. Without clever data structures the communication overhead will lead to an unacceptable performance drop when using thousands of processors. We show that with a good implementation it is possible to solve a linear system with 1011 unknowns in about 1.5 minutes on almost 10,000 processors. The data structures also allow for efficient adaptive mesh refinement, opening a wide range of applications to our solver.
  • Konferenzbeitrag
    How efficient are creatures with time-shuffled behaviors?
    (9th workshop on parallel systems and algorithms – workshop of the GI/ITG special interest groups PARS and PARVA, 2008) Ediger, Patrick; Hoffmann, Rolf; Halbach, Mathias
    The task of the creatures in the “creatures’ exploration problem” is to visit all empty cells in an environment with a minimum number of steps. We have analyzed this multi agent problem with time-shuffled algorithms (behaviors) in the cellular automata model. Ten different “uniform” (non-time-shuffled) algorithms with good performance from former investigations were used alternating in time. We designed three time-shuffling types differing in the way how the algorithms are interweaved. New metrics were defined for such a multi agent system, like the absolute and relative efficiency. The efficiency relates the work of an agent system to the work of a reference system. A reference system is such a system that can solve the problem with the lowest number of creatures with uniform or time-shuffled algorithms. Some time-shuffled systems reached high efficiency rates, but the most efficient system was a uniform one with 32 creatures. Among the most efficient successful systems the uniform ones are dominant. Shuffling algorithms resulted in better success rates for one creature. But this is not always the case for more than one creature.