57,965 research outputs found

    Staggered Heavy Baryon Chiral Perturbation Theory

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    Although taste violations significantly affect the results of staggered calculations of pseudoscalar and heavy-light mesonic quantities, those entering staggered calculations of baryonic quantities have not been quantified. Here I develop staggered chiral perturbation theory in the light-quark baryon sector by mapping the Symanzik action into heavy baryon chiral perturbation theory. For 2+1 dynamical quark flavors, the masses of flavor-symmetric nucleons are calculated to third order in partially quenched and fully dynamical staggered chiral perturbation theory. To this order the expansion includes the leading chiral logarithms, which come from loops with virtual decuplet-like states, as well as terms the order of the cubed pion mass, which come from loops with virtual octet-like states. Taste violations enter through the meson propagators in loops and tree-level terms the order of the squared lattice spacing. The pattern of taste symmetry breaking and the resulting degeneracies and mixings are discussed in detail. The resulting chiral forms are appropriate to lattice results obtained with operators already in use and could be used to study the restoration of taste symmetry in the continuum limit. I assume that the fourth root of the fermion determinant can be incorporated in staggered chiral perturbation theory using the replica method.Comment: 54 pages; v2: corrected discussion in Sec. III.C, conclusions unchange

    Magnetic Matrix Memory System-Patent

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    Magnetic matrix memory system for nondestructive reading of information contained in matri

    A personal computer-based, multitasking data acquisition system

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    A multitasking, data acquisition system was written to simultaneously collect meteorological radar and telemetry data from two sources. This system is based on the personal computer architecture. Data is collected via two asynchronous serial ports and is deposited to disk. The system is written in both the C programming language and assembler. It consists of three parts: a multitasking kernel for data collection, a shell with pull down windows as user interface, and a graphics processor for editing data and creating coded messages. An explanation of both system principles and program structure is presented

    MAPPER: A personal computer map projection tool

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    MAPPER is a set of software tools designed to let users create and manipulate map projections on a personal computer (PC). The capability exists to generate five popular map projections. These include azimuthal, cylindrical, mercator, lambert, and sinusoidal projections. Data for projections are contained in five coordinate databases at various resolutions. MAPPER is managed by a system of pull-down windows. This interface allows the user to intuitively create, view and export maps to other platforms

    Transparency in environment impact assessment decision-making: Recent developments in Western Australia

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    Transparency in decision-making, involving the establishment of explicit goals and objectives combined with open, facilitative procedures, has recently been advocated as an important principle for effective environmental impact assessment (EIA). This paper examines recent changes to EIA practice in Western Australia that emphasise clear procedures for decision-making. Current practices focus on objectives established for relevant environmental factors identified during the screening and scoping stages of EIA. These objectives are then used as decision criteria for project decision-making following public review. An example from a recent assessment is provided. Some strengths and weaknesses of this approach to transparent EIA decision-making are also examined
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