The Experts below are selected from a list of 153525 Experts worldwide ranked by ideXlab platform

J. Farroni - One of the best experts on this subject based on the ideXlab platform.

Liu Chao - One of the best experts on this subject based on the ideXlab platform.

  • SDAC: Porting Scientific Data to Spark RDDs
    2017
    Co-Authors: Tian Yang, Kenjiro Taura, Liu Chao
    Abstract:

    Scientific data processing has exposed a range of technical problems in industrial exploration and specific-domain applications due to its huge input volume and data format diversity. While Big Data analytic frameworks such as Hadoop and Spark lack their native supports for processing increasing heterogeneous scientific data efficiently. In this paper, we introduce our work named SDAC (Scientific Data Auto Chunk) for porting various scientific data to RDDs to support parallel processing and analytics in Apache Spark framework. With the integration of auto-chunk task granularity-specify method, a better-planned theoretical pipeline can be derived to navigate data partitioning and parallel I/O. We showcase performance comparison with H5Spark within 6 benchmarks in both standalone and Distributed Mode. Experimental results showed SDAC module achieved an overall improvement of 2.1 times over H5Spark in standalone Mode, and 1.34 times in Distributed Mode.

  • NPC - SDAC: Porting Scientific Data to Spark RDDs
    Lecture Notes in Computer Science, 2017
    Co-Authors: Tian Yang, Kenjiro Taura, Liu Chao
    Abstract:

    Scientific data processing has exposed a range of technical problems in industrial exploration and specific-domain applications due to its huge input volume and data format diversity. While Big Data analytic frameworks such as Hadoop and Spark lack their native supports for processing increasing heterogeneous scientific data efficiently. In this paper, we introduce our work named SDAC (Scientific Data Auto Chunk) for porting various scientific data to RDDs to support parallel processing and analytics in Apache Spark framework. With the integration of auto-chunk task granularity-specify method, a better-planned theoretical pipeline can be derived to navigate data partitioning and parallel I/O. We showcase performance comparison with H5Spark within 6 benchmarks in both standalone and Distributed Mode. Experimental results showed SDAC module achieved an overall improvement of 2.1 times over H5Spark in standalone Mode, and 1.34 times in Distributed Mode.

Jesper Laegsgaard - One of the best experts on this subject based on the ideXlab platform.

  • Cross-correlated imaging of single-Mode photonic crystal rod fiber with Distributed Mode filtering.
    Optics Express, 2013
    Co-Authors: Marko Laurila, Thomas Tanggaard Alkeskjold, Jes Broeng, Jesper Laegsgaard, Roman Barankov, Mette Marie Jørgensen, Siddharth Ramachandran
    Abstract:

    Photonic crystal bandgap fibers employing Distributed Mode filtering design provide near diffraction-limited light outputs, a critical property of fiber-based high-power lasers. Microstructure of the fibers is tailored to achieve single-Mode operation at specific wavelength by resonant Mode coupling of higher-order Modes. We analyze the modal regimes of the fibers having a Mode field diameter of 60 µm by the cross-correlated (C2) imaging method in different wavelength ranges and evaluate the sensitivity of the modal content to various input-coupling conditions. As a result, we experimentally identify regimes of resonant coupling between higher-order core Modes and cladding band. We demonstrate a passive fiber design in which the higher-order modal content inside the single-Mode guiding regime is suppressed by at least 20 dB even for significantly misaligned input-coupling configurations.

  • Cross-correlated imaging of Distributed Mode filtering rod fiber
    Proceedings of SPIE, 2013
    Co-Authors: Marko Laurila, Thomas Tanggaard Alkeskjold, Jes Broeng, Jesper Laegsgaard, Roman Barankov, Mette Marie Jørgensen, Sidsel Rübner Petersen, Siddharth Ramachandran
    Abstract:

    We analyze the modal properties of an 85μm core Distributed Mode filtering rod fiber using cross-correlated (C 2 ) imaging. We evaluate suppression of higher-order Modes (HOMs) under severely misaligned Mode excitation and identify a single-Mode regime where HOMs are suppressed by more than 20dB.

  • Distributed Mode filtering rod fiber amplifier delivering 292W with improved Mode stability
    Optics Express, 2012
    Co-Authors: Marko Laurila, Thomas Tanggaard Alkeskjold, Jes Broeng, Mette Marie Jørgensen, Kristian Rymann Hansen, Jesper Laegsgaard
    Abstract:

    We demonstrate a high power fiber (85μm core) amplifier delivering up to 292Watts of average output power using a Mode-locked 30ps source at 1032nm. Utilizing a single Mode Distributed Mode filter bandgap rod fiber, we demonstrate 44% power improvement before the threshold-like onset of Mode instabilities by operating the rod fiber in a leaky waveguide regime. We investigate the guiding dynamics of the rod fiber and report a distinct bandgap blue-shifting as function of increased signal power level. Furthermore, we theoretically analyze the guiding dynamics of the DMF rod fiber and explain the bandgap blue-shifting with thermally induced refractive index change of the refractive index profile.

  • Highly efficient high power single-Mode fiber amplifier utilizing the Distributed Mode filtering bandgap rod fiber
    Proceedings of SPIE, 2012
    Co-Authors: Marko Laurila, Thomas Tanggaard Alkeskjold, Jes Broeng, Mette Marie Jørgensen, Sidsel Rübner Petersen, Jesper Laegsgaard
    Abstract:

    We report on an ytterbium doped single Mode Distributed Mode filtering rod fiber in an amplifier configuration delivering high average output power, up to 292 watts, using a Mode-locked 30ps source at 1032nm with good power conversion efficiency. We study the modal stability of the output beam at high average output power levels and demonstrate a 44% power improvement before the threshold-like onset of Mode instabilities by operating the rod fiber in a leaky waveguide regime. We investigate the guiding dynamics of the rod fiber and explain the improved performance by thermally induced refractive index profile change.

  • Distributed Mode Filtering Rod Fiber Amplifier With Improved Mode Stability
    Lasers Sources and Related Photonic Devices, 2012
    Co-Authors: Marko Laurila, Thomas Tanggaard Alkeskjold, Jes Broeng, Jesper Laegsgaard
    Abstract:

    We report 216W of average output power from a photonic crystal rod fiber amplifier. We demonstrate almost 50% power improvement of the Mode onset instability by operating the rod fiber in a leaky guiding regime.

S. Heinemann - One of the best experts on this subject based on the ideXlab platform.

A. Galvanauskas - One of the best experts on this subject based on the ideXlab platform.