164 research outputs found
Dynamic Quality Metric Oriented Error-bounded Lossy Compression for Scientific Datasets
With the ever-increasing execution scale of high performance computing (HPC)
applications, vast amounts of data are being produced by scientific research
every day. Error-bounded lossy compression has been considered a very promising
solution to address the big-data issue for scientific applications because it
can significantly reduce the data volume with low time cost meanwhile allowing
users to control the compression errors with a specified error bound. The
existing error-bounded lossy compressors, however, are all developed based on
inflexible designs or compression pipelines, which cannot adapt to diverse
compression quality requirements/metrics favored by different application
users. In this paper, we propose a novel dynamic quality metric oriented
error-bounded lossy compression framework, namely QoZ. The detailed
contribution is three-fold. (1) We design a novel highly-parameterized
multi-level interpolation-based data predictor, which can significantly improve
the overall compression quality with the same compressed size. (2) We design
the error-bounded lossy compression framework QoZ based on the adaptive
predictor, which can auto-tune the critical parameters and optimize the
compression result according to user-specified quality metrics during online
compression. (3) We evaluate QoZ carefully by comparing its compression quality
with multiple state-of-the-arts on various real-world scientific application
datasets. Experiments show that, compared with the second-best lossy
compressor, QoZ can achieve up to 70% compression ratio improvement under the
same error bound, up to 150% compression ratio improvement under the same PSNR,
or up to 270% compression ratio improvement under the same SSIM
SRN-SZ: Deep Leaning-Based Scientific Error-bounded Lossy Compression with Super-resolution Neural Networks
The fast growth of computational power and scales of modern super-computing
systems have raised great challenges for the management of exascale scientific
data. To maintain the usability of scientific data, error-bound lossy
compression is proposed and developed as an essential technique for the size
reduction of scientific data with constrained data distortion. Among the
diverse datasets generated by various scientific simulations, certain datasets
cannot be effectively compressed by existing error-bounded lossy compressors
with traditional techniques. The recent success of Artificial Intelligence has
inspired several researchers to integrate neural networks into error-bounded
lossy compressors. However, those works still suffer from limited compression
ratios and/or extremely low efficiencies. To address those issues and improve
the compression on the hard-to-compress datasets, in this paper, we propose
SRN-SZ, which is a deep learning-based scientific error-bounded lossy
compressor leveraging the hierarchical data grid expansion paradigm implemented
by super-resolution neural networks. SRN-SZ applies the most advanced
super-resolution network HAT for its compression, which is free of time-costing
per-data training. In experiments compared with various state-of-the-art
compressors, SRN-SZ achieves up to 75% compression ratio improvements under the
same error bound and up to 80% compression ratio improvements under the same
PSNR than the second-best compressor
Long COVID and its association with neurodegenerative diseases: pathogenesis, neuroimaging, and treatment
Corona Virus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has presented unprecedented challenges to the world. Changes after acute COVID-19 have had a significant impact on patients with neurodegenerative diseases. This study aims to explore the mechanism of neurodegenerative diseases by examining the main pathways of central nervous system infection of SARS-CoV-2. Research has indicated that chronic inflammation and abnormal immune response are the primary factors leading to neuronal damage and long-term consequences of COVID-19. In some COVID-19 patients, the concurrent inflammatory response leads to increased release of pro-inflammatory cytokines, which may significantly impact the prognosis. Molecular imaging can accurately assess the severity of neurodegenerative diseases in patients with COVID-19 after the acute phase. Furthermore, the use of FDG-PET is advocated to quantify the relationship between neuroinflammation and psychiatric and cognitive symptoms in patients who have recovered from COVID-19. Future development should focus on aggressive post-infection control of inflammation and the development of targeted therapies that target ACE2 receptors, ERK1/2, and Ca2+
Effects of Chinese Medicine Tong xinluo on Diabetic Nephropathy via Inhibiting TGF- β
Diabetic nephropathy (DN) is a major cause of chronic kidney failure and characterized by interstitial and glomeruli fibrosis. Epithelial-to-mesenchymal transition (EMT) plays an important role in the pathogenesis of DN. Tong xinluo (TXL), a Chinese herbal compound, has been used in China with established therapeutic efficacy in patients with DN. To investigate the molecular mechanism of TXL improving DN, KK-Ay mice were selected as models for the evaluation of pathogenesis and treatment in DN. In vitro, TGF-β1 was used to induce EMT. Western blot (WB), immunofluorescence staining, and real-time polymerase chain reaction (RT-PCR) were applied to detect the changes of EMT markers in vivo and in vitro, respectively. Results showed the expressions of TGF-β1 and its downstream proteins smad3/p-smad3 were greatly reduced in TXL group; meantime, TXL restored the expression of smad7. As a result, the expressions of collagen IV (Col IV) and fibronectin (FN) were significantly decreased in TXL group. In vivo, 24 h-UAER (24-hour urine albumin excretion ratio) and BUN (blood urea nitrogen) were decreased and Ccr (creatinine clearance ratio) was increased in TXL group compared with DN group. In summary, the present study demonstrates that TXL successfully inhibits TGF-β1-induced epithelial-to-mesenchymal transition in DN, which may account for the therapeutic efficacy in TXL-mediated renoprotection
C-Coll: Introducing Error-bounded Lossy Compression into MPI Collectives
With the ever-increasing computing power of supercomputers and the growing
scale of scientific applications, the efficiency of MPI collective
communications turns out to be a critical bottleneck in large-scale distributed
and parallel processing. Large message size in MPI collectives is a
particularly big concern because it may significantly delay the overall
parallel performance. To address this issue, prior research simply applies the
off-the-shelf fix-rate lossy compressors in the MPI collectives, leading to
suboptimal performance, limited generalizability, and unbounded errors. In this
paper, we propose a novel solution, called C-Coll, which leverages
error-bounded lossy compression to significantly reduce the message size,
resulting in a substantial reduction in communication cost. The key
contributions are three-fold. (1) We develop two general, optimized
lossy-compression-based frameworks for both types of MPI collectives
(collective data movement as well as collective computation), based on their
particular characteristics. Our framework not only reduces communication cost
but also preserves data accuracy. (2) We customize an optimized version based
on SZx, an ultra-fast error-bounded lossy compressor, which can meet the
specific needs of collective communication. (3) We integrate C-Coll into
multiple collectives, such as MPI_Allreduce, MPI_Scatter, and MPI_Bcast, and
perform a comprehensive evaluation based on real-world scientific datasets.
Experiments show that our solution outperforms the original MPI collectives as
well as multiple baselines and related efforts by 3.5-9.7X.Comment: 12 pages, 15 figures, 5 tables, submitted to SC '2
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