181 research outputs found
Ginkgo: A Modern Linear Operator Algebra Framework for High Performance Computing
© ACM, YYYY. This is the author's version of the work "Anzt, H., Cojean, T., Flegar, G., Göbel, F., Grützmacher, T., Nayak, P., ... & Quintana-Ortí, E. S. (2022). Ginkgo: A modern linear operator algebra framework for high performance computing. ACM Transactions on Mathematical Software (TOMS), 48(1), 1-33". It is posted here by permission of ACM for your personal use. Not for redistribution. The definitive version was published in ACM Transactions on Mathematical Software, {VOL48, ISS 1, (MAR 2022)} http://doi.acm.org/10.1145/3480935"[EN] In this article, we present GINKGO, a modern C++ math library for scientific high performance computing. While classical linear algebra libraries act on matrix and vector objects, Gnswo's design principle abstracts all functionality as linear operators," motivating the notation of a "linear operator algebra library" GINKGO'S current focus is oriented toward providing sparse linear algebra functionality for high performance graphics processing unit (GPU) architectures, but given the library design, this focus can be easily extended to accommodate other algorithms and hardware architectures. We introduce this sophisticated software architecture that separates core algorithms from architecture-specific backends and provide details on extensibility and sustainability measures. We also demonstrate GINKGO'S usability by providing examples on how to use its functionality inside the MFEM and deal.ii finite element ecosystems. Finally, we offer a practical demonstration of GINKGO'S high performance on state-of-the-art GPU architectures.This work was supported by the "Impuls und Vernetzungsfond of the Helmholtz Association" under grant VH-NG-1241. G. Flegar and E. S. Quintana-Orti were supported by project TIN2017-82972-R of the MINECO and FEDER and the H2020 EU FETHPC Project 732631 "OPRECOMP". This researchwas also supported by the Exascale Computing Project (17-SC-20-SC), a collaborative effort of the U.S. Department of Energy Office of Science and the National Nuclear Security Administration. The experiments on the NVIDIA A100 GPU were performed on the HAICORE@KIT partition, funded by the "Impuls und Vernetzungsfond" of the Helmholtz Association. The experiments on the AMD MI100 GPU were performed on Tulip, an early-access platform hosted by HPE.Anzt, H.; Cojean, T.; Flegar, G.; Göbel, F.; Grützmacher, T.; Nayak, P.; Ribizel, T.... (2022). Ginkgo: A Modern Linear Operator Algebra Framework for High Performance Computing. ACM Transactions on Mathematical Software. 48(1):1-33. https://doi.org/10.1145/348093513348
Coexistence of Weak Localization and a Metallic Phase in Si/SiGe Quantum Wells
Magnetoresistivity measurements on p-type Si/SiGe quantum wells reveal the
coexistence of a metallic behavior and weak localization. Deep in the metallic
regime, pronounced weak localization reduces the metallic behavior around zero
magnetic field without destroying it. In the insulating phase, a positive
magnetoresistivity emerges close to B=0, possibly related to spin-orbit
interactions.Comment: 4 pages, 3 figure
GeSn/SiGeSn Heterostructure and Multi Quantum Well Lasers
GeSn and SiGeSn are promising materials for the fabrication of a group IV laser source offering a number of design options from bulk to heterostructures and quantum wells. Here, we investigate GeSn/SiGeSn multi quantum wells using the optically pumped laser effect. Three complex heterostructures were grown on top of 200 nm thick strain-relaxed Ge0.9Sn0.1 buffers. The lasing is investigated in terms of threshold and maximal lasing operation temperature by comparing multiple quantum well to double heterostructure samples. Pumping under two different wavelengths of 1064 and 1550 nm yields comparable lasing thresholds. The design with multi quantum wells reduces the lasing threshold to 40 ± 5 kW/cm2 at 20 K, almost 10 times lower than for bulk structures. Moreover, 20 K higher maximal lasing temperatures were found for lower energy pumping of 1550 nm
Formation of Polymethyl(methylene)aluminum
Sinn H, Hinck H, Bandermann F, Grützmacher H-F. Formation of Polymethyl(methylene)aluminum. Angewandte Chemie, International Edition in English. 1968;7(3):217
Die Aufklärung der Noludarzwischenfälle im Hamburger Hafenviertel (St. Pauli) mit Hilfe kombinierter Analysenmethoden
Arnold W, Grützmacher H-F. Die Aufklärung der Noludarzwischenfälle im Hamburger Hafenviertel (St. Pauli) mit Hilfe kombinierter Analysenmethoden. Deutsche Zeitschrift für die gesamte gerichtliche Medizin. 1969;65(1):44-60.In den Jahren 1965/66 kam es vermehrt zu Beraubungsdelikten im Hamburger Hafenviertel (St. Pauli). Nach den Tatumständen war anzunehmen, daß wahrscheinlich den meist mehr oder weniger alkoholisierten Opfern unbeobachtet ein schnell wirkendes Schlaf- oder Betäubungsmittel beigebracht wurde. Die chemische Untersuchung polizeilich sichergestellter Urinproben der Geschädigten führte zur Isolierung eines Fremdstoffes aus einzelnen dieser Harnasservate, der mit Hilfe kombinierter Analysenmethoden (präparative Dünnschichtchromatographie, IR- und Massenspektrographie) als ein neuer Noludar-Metabolit (2,4-Dioxo-3,3-diäthyl-5-methyl-6-hydroxypiperidin) identifiziert wurde
Constatação da diferença da razão sexual de Tibraca limbativentris (Hemiptera: Pentatomidae) amostrados em regiões orizícolas de Santa Catarina e do Rio Grande do Sul.
Esse trabalho teve por objetivo obter amostras de T. limbativentris das regiões de importância orizícola nos estados de Santa Catarina (SC) e Rio Grande do Sul (RS), para posterior caracterização molecular dos indivíduos coletados e relacionar esta caracterização com o local de origem
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