1,483 research outputs found

    Techniques for containing error propagation in compression/decompression schemes

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    Data compression has the potential for increasing the risk of data loss. It can also cause bit error propagation, resulting in catastrophic failures. There are a number of approaches possible for containing error propagation due to data compression: (1) data retransmission; (2) data interpolation; (3) error containment; and (4) error correction. The most fruitful techniques will be ones where error containment and error correction are integrated with data compression to provide optimal performance for both. The error containment characteristics of existing compression schemes should be analyzed for their behavior under different data and error conditions. The error tolerance requirements of different data sets need to be understood, so guidelines can then be developed for matching error requirements to suitable compression algorithms

    Data compression opportunities in EOSDIS

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    The Earth Observing System Data and Information System (EOSDIS) is described in terms of its data volume, data rate, and data distribution requirements. Opportunities for data compression in EOSDIS are discussed

    EOSDIS/DADS requirements

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    A brief summary of the Earth Observing System Data and Information System (EOSDIS) Core System (ECS) Data Archive and Distribution System (DADS) requirements is given. Among the requirements are the following: the ECS relationship to EOSDIS Version-O; phased implementation of ECS; and data ingest, archive, and distribution daily data volumes anticipated at each of the 7 Distributed Active Archive Centers (DAAC's)

    Dynamical Properties of the Mukhanov-Sasaki Hamiltonian in the context of adiabatic vacua and the Lewis-Riesenfeld invariant

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    We use the method of the Lewis-Riesenfeld invariant to analyze the dynamical properties of the Mukhanov-Sasaki Hamiltonian and, following this approach, investigate whether we can obtain possible candidates for initial states in the context of inflation considering a quasi-de Sitter spacetime. Our main interest lies in the question to which extent these already well-established methods at the classical and quantum level for finitely many degrees of freedom can be generalized to field theory. As our results show, a straightforward generalization does in general not lead to a unitary operator on Fock space that implements the corresponding time-dependent canonical transformation associated with the Lewis-Riesenfeld invariant. The action of this operator can be rewritten as a time-dependent Bogoliubov transformation and we show that its generalization to Fock space has to be chosen appropriately in order that the Shale-Stinespring condition is not violated, where we also compare our results to already existing ones in the literature. Furthermore, our analysis relates the Ermakov differential equation that plays the role of an auxiliary equation, whose solution is necessary to construct the Lewis-Riesenfeld invariant, as well as the corresponding time-dependent canonical transformation to the defining differential equation for adiabatic vacua. Therefore, a given solution of the Ermakov equation directly yields a full solution to the differential equation for adiabatic vacua involving no truncation at some adiabatic order. As a consequence, we can interpret our result obtained here as a kind of non-squeezed Bunch-Davies mode, where the term non-squeezed refers to a possible residual squeezing that can be involved in the unitary operator for certain choices of the Bogoliubov map.Comment: 40 pages, 5 figures, minor changes: slightly rewrote the introduction, extended the discussion on the infrared modes, corrected typos and added reference

    Spatial model of forest fire danger

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    Neural mechanisms of pathogen-modulated feeding behaviour in Drosophila

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    NSSDC Conference on Mass Storage Systems and Technologies for Space and Earth Science Applications, volume 1

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    Papers and viewgraphs from the conference are presented. This conference served as a broad forum for the discussion of a number of important issues in the field of mass storage systems. Topics include magnetic disk and tape technologies, optical disks and tape, software storage and file management systems, and experiences with the use of a large, distributed storage system. The technical presentations describe, among other things, integrated mass storage systems that are expected to be available commercially. Also included is a series of presentations from Federal Government organizations and research institutions covering their mass storage requirements for the 1990's

    All-inorganic core-shell silica-titania mesoporous colloidal nanoparticles showing orthogonal functionality

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    Colloidal mesoporous silica (CMS) nanoparticles with a thin titania-enriched outer shell showing a spatially resolved functionality were synthesized by a delayed co-condensation approach. The titaniashell can serve as a selective nucleation site for the growth of nanocrystalline anatase clusters. These fully inorganic pure silica-core titania-enriched shell mesoporous nanoparticles show orthogonal functionality, demonstrated through the selective adsorption of a carboxylate-containing ruthenium N3-dye. UV-Vis and fluorescence spectroscopy indicate the strong interaction of the N3-dye with the titania-phase at the outer shell of the CMS nanoparticles. In particular, this interaction and thus the selective functionalization are greatly enhanced when anatase nanocrystallites are nucleated at the titania-enriched shell surface

    NSSDC Conference on Mass Storage Systems and Technologies for Space and Earth Science Applications, volume 2

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    This report contains copies of nearly all of the technical papers and viewgraphs presented at the NSSDC Conference on Mass Storage Systems and Technologies for Space and Earth Science Application. This conference served as a broad forum for the discussion of a number of important issues in the field of mass storage systems. Topics include the following: magnetic disk and tape technologies; optical disk and tape; software storage and file management systems; and experiences with the use of a large, distributed storage system. The technical presentations describe, among other things, integrated mass storage systems that are expected to be available commercially. Also included is a series of presentations from Federal Government organizations and research institutions covering their mass storage requirements for the 1990's

    First-Year College Seminar as a Tool for Nutrition Education and Food Preparation Skills

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    The obesity epidemic is steadily increasing and affecting all age groups. Obesity rates among young adults are scarcely reported but merit special attention as being overweight during young adulthood will likely result in being overweight or obese throughout adulthood. Because college students are still forming lifestyle patterns, the university setting is ideal for intervention and educating young adults on the importance of developing and maintaining healthy behaviors. This study evaluated whether participation in a 16-week first-year college seminar cooking course increased students’ self-efficacy in food preparation skills and dietary behaviors. Significant changes in food preparation skills were observed between before and after participation (p\u3c0.05) but self-efficacy, overall, did not increase significantly. Institutions of higher education should provide experiential learning opportunities to improve food preparation skills and hence dietary habits of young adults by developing and implementing programs such as first-year seminars focusing on hands-on food preparation basics and techniques
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