529 research outputs found

    LIKWID Monitoring Stack: A flexible framework enabling job specific performance monitoring for the masses

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    System monitoring is an established tool to measure the utilization and health of HPC systems. Usually system monitoring infrastructures make no connection to job information and do not utilize hardware performance monitoring (HPM) data. To increase the efficient use of HPC systems automatic and continuous performance monitoring of jobs is an essential component. It can help to identify pathological cases, provides instant performance feedback to the users, offers initial data to judge on the optimization potential of applications and helps to build a statistical foundation about application specific system usage. The LIKWID monitoring stack is a modular framework build on top of the LIKWID tools library. It aims on enabling job specific performance monitoring using HPM data, system metrics and application-level data for small to medium sized commodity clusters. Moreover, it is designed to integrate in existing monitoring infrastructures to speed up the change from pure system monitoring to job-aware monitoring.Comment: 4 pages, 4 figures. Accepted for HPCMASPA 2017, the Workshop on Monitoring and Analysis for High Performance Computing Systems Plus Applications, held in conjunction with IEEE Cluster 2017, Honolulu, HI, September 5, 201

    Validation of hardware events for successful performance pattern identification in High Performance Computing

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    Hardware performance monitoring (HPM) is a crucial ingredient of performance analysis tools. While there are interfaces like LIKWID, PAPI or the kernel interface perf\_event which provide HPM access with some additional features, many higher level tools combine event counts with results retrieved from other sources like function call traces to derive (semi-)automatic performance advice. However, although HPM is available for x86 systems since the early 90s, only a small subset of the HPM features is used in practice. Performance patterns provide a more comprehensive approach, enabling the identification of various performance-limiting effects. Patterns address issues like bandwidth saturation, load imbalance, non-local data access in ccNUMA systems, or false sharing of cache lines. This work defines HPM event sets that are best suited to identify a selection of performance patterns on the Intel Haswell processor. We validate the chosen event sets for accuracy in order to arrive at a reliable pattern detection mechanism and point out shortcomings that cannot be easily circumvented due to bugs or limitations in the hardware

    The outer envelope protein OEP24 from pea chloroplasts can functionally replace the mitochondrial VDAC in yeast

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    AbstractThe chloroplastic outer envelope protein OEP24 from pea forms a high-conductance low specificity solute channel as shown by in vitro studies. In order to establish its function also in an in vivo-like system, the gene encoding OEP24 was transformed into a yeast strain which lacks the general mitochondria solute channel porin, also known as voltage-dependent anion channel (VDAC). Transformation of the yeast VDAC(−) strain with the OEP24 gene resulted in the recovery of a phenotype indistinguishable from the wild-type. The OEP24 polypeptide is targeted to the mitochondrial outer membrane in this heterologous system. We conclude that OEP24 forms a solute channel in pea chloroplasts in planta

    Einfluss des EinfÀrbens auf die Materialeigenschaften von Zirkoniumdioxid

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    In heutiger Zeit verlangen zahnĂ€rztliche Therapien nach Rekonstruktionen von höchster Ă€sthetischer QualitĂ€t und BiokompatibilitĂ€t. Yttrium-stabilisiertes Zirkoniumdioxid (Y-TZP) spielt hierbei eine große Rolle. Es dient als GerĂŒstwerkstoff, welcher anschließend mit transluzenten Keramiken verblendet wird. EinfĂ€rben des ZrO2 erlaubt die Herstellung von hochĂ€sthetischen Restaurationen. Untersucht wurde der Einfluss des EinfĂ€rbens auf die Kristallstruktur und bestimmte Materialeigenschaften des ZrO2. Röntgendiffraktometrischen Untersuchungen zeigten keine Unterschiede der Kristallstruktur zwischen ungefĂ€rbtem und gefĂ€rbtem ZrO2. In allen untersuchten Proben war eine tetragonale Phase nachweisbar. Im REM zeigten alle untersuchten Proben eine homogene OberflĂ€che ohne offensichtliche Restporen oder Risse. Ein Einfluss der FarbintensitĂ€t auf GefĂŒgebild und KorngrĂ¶ĂŸe war nicht zu erkennen. Durch EDX-Analyse wurde festgestellt, dass in der FĂ€rbelösung Fe2O3 enthalten war. Biegebruchversuche zeigten, dass das EinfĂ€rben von ZrO2 keinen korrelierenden Einfluss auf dessen Biegefestigkeit hat. FĂ€rben von Y-TZP hatte keinen positiven oder negativen Effekt auf den Verbund zu den untersuchten Befestigungskompositen. Variolink II (+ Metalprimer II) wies in dieser Studie höhere Druck-Scher-Festigkeiten auf als RelyX Unicem. Nach kĂŒnstlicher Alterung im Thermocycler traten bei beiden Befestigungskompositen signifikante Druck-Scher-Festigkeitsverluste auf. Bei korrekter zahntechnischer Verarbeitung erreicht gefĂ€rbtes ZrO2 die gleichen mechanischen Eigenschaften wie ungefĂ€rbtes und kann klinisch verwendet werden. Das Eingliedern eingefĂ€rbter ZrO2-Restaurationen mit Befestigungskompositen ist zu empfehlen. Variolink II (+ Metalprimer II) hatte eine signifikant höhere Verbundfestigkeit zu Zirkoniumdioxid als RelyX Unicem und ist daher fĂŒr die Befestigung bestimmter Restaurationen zu bevorzugen

    An Ocean View of the Early Cenozoic Greenhouse World

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    Some comparison theorems for weak nonnegative splittings of bounded operators

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    AbstractThe comparison of the asymptotic rates of convergence of two iteration matrices induced by two splittings of the same matrix has arisen in the works of many authors. In this paper we derive new comparison theorems for weak nonnegative splittings and weak splittings of bounded operators in a general Banach space and rather general cones, and in a Hilbert space, which extend some of the results obtained by WoĆșnicki (Japan J. Indust. Appl. Math. 11(1994) 289–342) and Marek and Szyld (Numer. Math. 44(1984) 23–35). Furthermore, we present new theorems also for bounded operator which extend some results by Csordas and Varga (Numer. Math. 44. (1984) 23–35) for weak nonnegative splittings of matrices

    Astronomical calibration of the Ypresian timescale: implications for seafloor spreading rates and the chaotic behavior of the solar system?

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    Abstract. To fully understand the global climate dynamics of the warm early Eocene with its reoccurring hyperthermal events, an accurate high-fidelity age model is required. The Ypresian stage (56–47.8 Ma) covers a key interval within the Eocene as it ranges from the warmest marine temperatures in the early Eocene to the long-term cooling trends in the middle Eocene. Despite the recent development of detailed marine isotope records spanning portions of the Ypresian stage, key records to establish a complete astronomically calibrated age model for the Ypresian are still missing. Here we present new high-resolution X-ray fluorescence (XRF) core scanning iron intensity, bulk stable isotope, calcareous nannofossil, and magnetostratigraphic data generated on core material from ODP Sites 1258 (Leg 207, Demerara Rise), 1262, 1263, 1265, and 1267 (Leg 208, Walvis Ridge) recovered in the equatorial and South Atlantic Ocean. By combining new data with published records, a 405 kyr eccentricity cyclostratigraphic framework was established, revealing a 300–400 kyr long condensed interval for magnetochron C22n in the Leg 208 succession. Because the amplitudes are dominated by eccentricity, the XRF data help to identify the most suitable orbital solution for astronomical tuning of the Ypresian. Our new records fit best with the La2010b numerical solution for eccentricity, which was used as a target curve for compiling the Ypresian astronomical timescale (YATS). The consistent positions of the very long eccentricity minima in the geological data and the La2010b solution suggest that the macroscopic feature displaying the chaotic diffusion of the planetary orbits, the transition from libration to circulation in the combination of angles in the precession motion of the orbits of Earth and Mars, occurred â€‰âˆŒâ€‰â€Ż52 Ma. This adds to the geological evidence for the chaotic behavior of the solar system. Additionally, the new astrochronology and revised magnetostratigraphy provide robust ages and durations for Chrons C21n to C24n (47–54 Ma), revealing a major change in spreading rates in the interval from 51.0 to 52.5 Ma. This major change in spreading rates is synchronous with a global reorganization of the plate–mantle system and the chaotic diffusion of the planetary orbits. The newly provided YATS also includes new absolute ages for biostratigraphic events, magnetic polarity reversals, and early Eocene hyperthermal events. Our new bio- and magnetostratigraphically calibrated stable isotope compilation may act as a reference for further paleoclimate studies of the Ypresian, which is of special interest because of the outgoing warming and increasingly cooling phase. Finally, our approach of integrating the complex comprehensive data sets unearths some challenges and uncertainties but also validates the high potential of chemostratigraphy, magnetostratigraphy, and biostratigraphy in unprecedented detail being most significant for an accurate chronostratigraphy

    Semantics and technologies in modern design of interior stairs

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    Use of metal in the design of interior stairs presents new features for shaping, and can be implemented using different technologies. The article discusses the features of design and production technologies of forged metal spiral staircase considering the image semantics based on the historical and cultural heritage. To achieve the objective was applied structural-semantic method (to identify the organization of structure and semantic features of the artistic image), engineering methods (to justify the construction of the object), anthropometry method and ergonomics (to provide usability), methods of comparative analysis (to reveale the features of the way the ladder in different periods of culture). According to the research results are as follows. Was revealed the semantics influence on the design of interior staircase that is based on the World Tree image. Also was suggested rational calculation of steps to ensure the required strength. And finally was presented technology, providing the realization of the artistic image. In the practical part of the work is presented version of forged staircase

    On the duration of magnetochrons C24r and C25n and the timing of early Eocene global warming events: Implications from the Ocean Drilling Program Leg 208 Walvis Ridge depth transect

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    Five sections drilled in multiple holes over a depth transect of more than 2200 m at the Walvis Ridge (SE Atlantic) during Ocean Drilling Program (ODP) Leg 208 resulted in the first complete early Paleogene deep-sea record. Here we present high-resolution stratigraphic records spanning a ~4.3 million yearlong interval of the late Paleocene to early Eocene. This interval includes the Paleocene-Eocene thermal maximum (PETM) as well as the Eocene thermal maximum (ETM) 2 event. A detailed chronology was developed with nondestructive X-ray fluorescence (XRF) core scanning records and shipboard color data. These records were used to refine the shipboard-derived spliced composite depth for each site and with a record from ODP Site 1051 were then used to establish a continuous time series over this interval. Extensive spectral analysis reveals that the early Paleogene sedimentary cyclicity is dominated by precession modulated by the short (100 kyr) and long (405 kyr) eccentricity cycles. Counting of precession-related cycles at multiple sites results in revised estimates for the duration of magnetochrons C24r and C25n. Direct comparison between the amplitude modulation of the precession component derived from XRF data and recent models of Earth’s orbital eccentricity suggests that the onset of the PETM and ETM2 are related to a 100-kyr eccentricity maximum. Both events are approximately a quarter of a period offset from a maximum in the 405-kyr eccentricity cycle, with the major difference that the PETM is lagging and ETM2 is leading a 405-kyr eccentricity maximum. Absolute age estimates for the PETM, ETM2, and the magnetochron boundaries that are consistent with recalibrated radiometric ages and recent models of Earth’s orbital eccentricity cannot be precisely determined at present because of too large uncertainties in these methods. Nevertheless, we provide two possible tuning options, which demonstrate the potential for the development of a cyclostratigraphic framework based on the stable 405-kyr eccentricity cycle for the entire Paleogene
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