| 1. |
- Keller, Jörg, et al.
(författare)
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Optimized On-Chip-Pipelining for Memory-Intensive Computations on Multi-Core Processors with Explicit Memory Hierarchy
- 2012
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Ingår i: Journal of Universal Computer Science. - : Graz University of Technology, Institut f�r Informationssysteme und Computer Medien (IICM) / Graz University of Technology and Know-Center. - 0948-695X. ; 18:14, s. 1987-2023
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Tidskriftsartikel (refereegranskat)abstract
- Limited bandwidth to off-chip main memory tends to be a performance bottleneck in chip multiprocessors, and this will become even more problematic with an increasing number of cores. Especially for streaming computations where the ratio between computational work and memory transfer is low, transforming the program into more memory-efficient code is an important program optimization.On-chip pipelining reorganizes the computation so that partial results of subtasks are forwarded immediately between the cores over the high-bandwidth internal network, in order to reduce the volume of main memory accesses, and thereby improves the throughput for memory-intensive computations. At the same time, throughput is also constrained by the limited amount of on-chip memory available for buffering forwarded data. By optimizing the mapping of tasks to cores, balancing a trade-off between load balancing, buffer memory consumption, and communication load on the on-chip network, a larger buffer size can be applied, resulting in less DMA communication and scheduling overhead.In this article, we consider parallel mergesort as a representative memory-intensive application in detail, and focus on the global merging phase, which is dominating the overall sorting time for larger data sets. We work out the technical issues of applying the on-chip pipelining technique, and present several algorithms for optimized mapping of merge trees to the multiprocessor cores. We also demonstrate how some of these algorithms can be used for mapping of other streaming task graphs.We describe an implementation of pipelined parallel mergesort for the Cell Broadband Engine, which serves as an exemplary target. We evaluate experimentally the influence of buffer sizes and mapping optimizations, and show that optimized on-chip pipelining indeed speeds up, for realistic problem sizes, merging times by up to 70% on QS20 and 143% on PS3 compared to the merge phase of CellSort, which was by now the fastest merge sort implementation on Cell.
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| 2. |
- Kessler, Christoph W., et al.
(författare)
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Program Composition and Optimization: An Introduction
- 2010
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Ingår i: Proceedings (abstracts collection) of the Dagstuhl Seminar 10191. - Dagstuhl, Germany : Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 3. |
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| 4. |
- Pupier, Marion, et al.
(författare)
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NMReDATA, a standard to report the NMR assignment and parameters of organic compounds
- 2018
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Ingår i: Magnetic Resonance in Chemistry. - : John Wiley & Sons. - 0749-1581 .- 1097-458X. ; 56:8, s. 703-715
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Tidskriftsartikel (refereegranskat)abstract
- Even though NMR has found countless applications in the field of small molecule characterization, there is no standard file format available for the NMR data relevant to structure characterization of small molecules. A new format is therefore introduced to associate the NMR parameters extracted from 1D and 2D spectra of organic compounds to the proposed chemical structure. These NMR parameters, which we shall call NMReDATA (for nuclear magnetic resonance extracted data), include chemical shift values, signal integrals, intensities, multiplicities, scalar coupling constants, lists of 2D correlations, relaxation times, and diffusion rates. The file format is an extension of the existing Structure Data Format, which is compatible with the commonly used MOL format. The association of an NMReDATA file with the raw and spectral data from which it originates constitutes an NMR record. This format is easily readable by humans and computers and provides a simple and efficient way for disseminating results of structural chemistry investigations, allowing automatic verification of published results, and for assisting the constitution of highly needed open-source structural databases.
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| 5. |
- Reichart, Bruno, et al.
(författare)
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Pig-to-non-human primate heart transplantation : The final step toward clinical xenotransplantation?
- 2020
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Ingår i: Journal of Heart and Lung Transplantation. - : Elsevier BV. - 1053-2498. ; 39:8, s. 751-757
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Tidskriftsartikel (refereegranskat)abstract
- Background: The demand for donated human hearts far exceeds the number available. Xenotransplantation of genetically modified porcine organs provides an alternative. In 2000, an Advisory Board of the International Society for Heart and Lung Transplantation set the benchmark for commencing clinical cardiac xenotransplantation as consistent 60% survival of non-human primates after life-supporting porcine heart transplantations. Recently, we reported the stepwise optimization of pig-to-baboon orthotopic cardiac xenotransplantation finally resulting in consistent success, with 4 recipients surviving 90 (n = 2), 182, and 195 days. Here, we report on 4 additional recipients, supporting the efficacy of our procedure. Results: The first 2 additional recipients succumbed to porcine cytomegalovirus (PCMV) infections on Days 15 and 27, respectively. In 2 further experiments, PCMV infections were successfully avoided, and 3-months survival was achieved. Throughout all the long-term experiments, heart, liver, and renal functions remained within normal ranges. Post-mortem cardiac diameters were slightly increased when compared with that at the time of transplantation but with no detrimental effect. There were no signs of thrombotic microangiopathy. The current regimen enabled the prolonged survival and function of orthotopic cardiac xenografts in altogether 6 of 8 baboons, of which 4 were now added. These results exceed the threshold set by the Advisory Board of the International Society for Heart and Lung Transplantation. Conclusions: The results of our current and previous experimental cardiac xenotransplantations together fulfill for the first time the pre-clinical efficacy suggestions. PCMV-positive donor animals must be avoided.
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