Data Compression in the Petascale Astronomy Era: a GERLUMPH case study

As the volume of data grows, astronomers are increasingly faced with choices on what data to keep -- and what to throw away. Recent work evaluating the JPEG2000 (ISO/IEC 15444) standards as a future data format standard in astronomy has shown promising results on observational data. However, there is still a need to evaluate its potential on other type of astronomical data, such as from numerical simulations. GERLUMPH (the GPU-Enabled High Resolution cosmological MicroLensing parameter survey) represents an example of a data intensive project in theoretical astrophysics. In the next phase of processing, the ~27 terabyte GERLUMPH dataset is set to grow by a factor of 100 -- well beyond the current storage capabilities of the supercomputing facility on which it resides. In order to minimise bandwidth usage, file transfer time, and storage space, this work evaluates several data compression techniques. Specifically, we investigate off-the-shelf and custom lossless compression algorithms as well as the lossy JPEG2000 compression format. Results of lossless compression algorithms on GERLUMPH data products show small compression ratios (1.35:1 to 4.69:1 of input file size) varying with the nature of the input data. Our results suggest that JPEG2000 could be suitable for other numerical datasets stored as gridded data or volumetric data. When approaching lossy data compression, one should keep in mind the intended purposes of the data to be compressed, and evaluate the effect of the loss on future analysis. In our case study, lossy compression and a high compression ratio do not significantly compromise the intended use of the data for constraining quasar source profiles from cosmological microlensing.Comment: 15 pages, 9 figures, 5 tables. Published in the Special Issue of Astronomy & Computing on The future of astronomical data format

Paul Vohl to James H. Meredith (3 October 1962)

https://egrove.olemiss.edu/mercorr_pro/1903/thumbnail.jp

Unearthing Defendants in Toxic Waste Litigation: Problems of Liability and Identification

This Comment examines two significant barriers to obtaining compensation from waste generators posed by traditional proof requirements, and proposes possible approaches for alleviating them. The author evaluates the plausibility of integrating strict products liability and risk share liability, an adaptation of market share liability, into a unified approach that may provide tort victims with greater access to legal remedies. The author suggests that the court adopt a more progressive analytical framework that is analogous to the theory articulated in Sindell v. Abbott Laboratories, and argues for an allocation of liability based on the relative risk share of generators in a toxic waste disposal market, comprised of an aggregate threat of harm to a plaintiff created by a dumpsite

New approaches to Volume and Velocity challenges of Modern Astronomy

Fundamental problems facing modern astronomy relate to processing, visualization, analysis, and remote access to data. As the volume and velocity at which data is generated and stored increases, new approaches, methods and analytical tools are required to let us fully explore information hidden within our data. In this talk, I discuss ways to enhance and streamline analysis tasks in surveys by adopting a set of informatics tricks—including concepts like display ecology, visual and immersive analytics, `single instruction, multiple visualizations`, graphics shaders, and data compression—to alleviate a number of bottlenecks and offer a better experience for individuals and research teams

Thin film GaAs photovoltaic solar energy cells

Fabrication process for thin film gallium arsenide photovoltaic solar energy cell

Materials and methods for large-area solar cells Final report, 17 Dec. 1964 - 16 Dec. 1965

Growth and evaluation of gallium arsenide-indium arsenide-aluminum foil structures in construction of thin film large area solar cells for satellite

Interaction between diets, polymorphisms and plasma lipid levels

Cardiovascular disease (CVD) is responsible for significant morbidity and mortality. Dietary guidelines that aim to manage fat intake reduce CVD, but an important interindividual variability in plasma lipid responsiveness is observed in individuals following these diets. This interdividual variability in response to diets may be attributable to several single nucleotide polymorphisms (SNPs) in genes encoding key proteins involved in lipoprotein metabolism. In this article, we discuss the effect of different diets, classified by type of dietary fats, on plasma lipid levels in relationship to various polymorphisms in key genes that may affect lipid and lipoprotein metabolism. In summary, various polymorphisms may predispose an individual to be more or less responsive to a specific dietary intervention; however, future studies need to be conducted to confirm the effect of these various SNPs. In conclusion, this article reinforces the importance of taking account genetic variability into account in order to personalize potential future dietary recommendations for the prevention and management of hyperlipidemia