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Auflistung nach Schlagwort "Experimental evaluation"

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  • Zeitschriftenartikel
    Evaluating the Vector Supercomputer SX-Aurora TSUBASA as a Co-Processor for In-Memory Database Systems
    (Datenbank-Spektrum: Vol. 19, No. 3, 2019) Pietrzyk, Johannes; Habich, Dirk; Damme, Patrick; Focht, Erich; Lehner, Wolfgang
    In-memory column-store database systems are state of the art for the efficient processing of analytical workloads. In these systems, data compression as well as vectorization play an important role. Currently, the vectorized processing is done using regular SIMD (Single Instruction Multiple Data) extensions of modern processors. For example, Intel’s latest SIMD extension supports 512-bit vector registers which allows the parallel processing of 8× 64-bit values. From a database system perspective, this vectorization technique is not only very interesting for compression and decompression to reduce the computational overhead, but also for all database operators like joins, scan, as well as groupings. In contrast to these SIMD extensions, NEC Corporation has recently introduced a novel pure vector engine (supercomputer) as a co-processor called SX-Aurora TSUBASA. This vector engine features a vector length of 16.384 bits with the world’s highest bandwidth of up to 1.2 TB/s, which perfectly fits to data-intensive applications like in-memory database systems. Therefore, we describe the unique architecture and properties of this novel vector engine in this paper. Moreover, we present selected in-memory column-store-specific evaluation results to show the benefits of this vector engine compared to regular SIMD extensions. Finally, we conclude the paper with an outlook on our ongoing research activities in this direction.
  • Zeitschriftenartikel
    The Development and Experimental Evaluation of a Focused Business Model Representation
    (Business & Information Systems Engineering: Vol. 57, No. 1, 2015) Roelens, Ben; Poels, Geert
    Business models (BM) are the central concept to understand the business logic of an organization. Enterprise modeling contributes to the conceptualization of BMs by providing explicit representations. A proper BM representation helps to increase the understanding and communication about the underlying knowledge for the stakeholders within a company. However, the existing enterprise modeling languages have a different and partial focus on the BM concept due to their various backgrounds. This prevents the large-scale adoption of these representations in practice. Therefore a focused BM viewpoint is developed, which explicitly facilitates the understanding about the underlying BM components. To this end, existing diagrams of the value delivery modeling language were adapted to prescriptions of the physics of notations, which is a normative theory for cognitive effectiveness of diagrammatic representations. The effect on the understanding was evaluated by an experiment with 93 master students. The results confirm the research hypothesis that the new BM viewpoint increases the understanding of the modeled BM components.