1,947 research outputs found

    Considerations for Estimating Remote Operator Dust Exposure Using Fixed-Point Samples on Continuous Mining Sections

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    Respirable dust studies were conducted at several underground coal mining operations to evaluate and compare the dust measurements of fixed-point machine-mounted samples on a continuous miner and personal samples of the remote miner operator. Fixed-point sampling was conducted at the right rear corner of the continuous miner which corresponded to the traditional location of the operator\u27s cab. Although it has been documented that higher concentrations of dust are present at the machine-mounted position, this work sought to determined whether a relationship exists between the concentrations at the fixed-point position and the dust levels experienced at the remote operator position and whether this relationship could be applied on a industry-wide basis. To achieve this objective, gravimetric samplers were used to collect respirable dust data on continuous miner sections. These samplers were placed at a fixed position at the cab location of the continuous mining machine and on or near the remote miner operator during the 1 shift/day sampling periods. Dust sampling took place at mines with a variety of geographic locations and in-mine conditions. The dust concentration data collected at each site and for each sampling period were reduced to ratios of fixed-point to operator concentration. The ratios were calculated to determine similarities, differences, and/or variability at the two positions. The data show that dust concentrations at the remote operator position were always lower than dust concentrations measured at the fixed-point continuous miner location. However, the ratios of fixed-point to remote operator dust levels showed little consistency from shift to shift or from operation to operation. The fact that these ratios are so variable may introduce some uncertainty into attempting to correlate dust exposures of the remote operator to dust levels measured on the continuous mining machine

    A generalization of Schur-Weyl duality with applications in quantum estimation

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    Schur-Weyl duality is a powerful tool in representation theory which has many applications to quantum information theory. We provide a generalization of this duality and demonstrate some of its applications. In particular, we use it to develop a general framework for the study of a family of quantum estimation problems wherein one is given n copies of an unknown quantum state according to some prior and the goal is to estimate certain parameters of the given state. In particular, we are interested to know whether collective measurements are useful and if so to find an upper bound on the amount of entanglement which is required to achieve the optimal estimation. In the case of pure states, we show that commutativity of the set of observables that define the estimation problem implies the sufficiency of unentangled measurements.Comment: The published version, Typos corrected, 40 pages, 2 figure

    Free Quantum Fields in 4D and Calabi-Yau Spaces

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    We develop general counting formulae for primary fields in free four dimensional (4D) scalar conformal field theory (CFT). Using a duality map between primary operators in scalar field theory and multi-variable polynomial functions subject to differential constraints, we identify a sector of holomorphic primary fields corresponding to polynomial functions on a class of permutation orbifolds. These orbifolds have palindromic Hilbert series, which indicates they are Calabi-Yau. We construct the top-dimensional holomorphic form expected from the Calabi-Yau property. This sector includes and extends previous constructions of infinite families of primary fields. We sketch the generalization of these results to free 4D vector and matrix CFTs.Comment: 6 page

    ANIMA OBSCURA

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    This technical paper presents the results of the past three years research and development work by an interdisciplinary team of artists, scholars, disability empowerment experts, engineers, computer scientists and medical doctors, working together to invent new cutting edge technologies for real people’s needs. The group has called itself SPIRITlevel (see www.smartlabcentre.com) and has aimed to harness and share the power of technology when invented by and for people with unlimited imaginations despite physical limitations. The project discussed is ‘ANIMA OBSCURA’: a showcase performance designed to demonstrate the empowering abilities of new technology in the performing arts, where bio-affective feedback systems and motion tracking technologies can be usefully (and invisibly) combined with live performance by disabled and able-bodied dancers, to allow every person to dance, move, and bring an augmented world to life. The showcase has broadcastable elements and scaleable format that makes it suitable for demonstration in hospital settings, rehabilitation units, art galleries, museums, and main stages. It can be utilised by individuals for personal therapy and healing, or used collaboratively in online game-playing between hospital beds or, in the ‘mainstream’, through webcast and broadcast formats

    COVID-19: Time for precision epidemiology

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    The global COVID-19 (SARS-CoV2, COVID-19) tsunami caused by SARSCoV2 is inundating and often-overwhelming health care systems in most countries and regions..

    Moving Towards the Post p < 0.05 Era via the Analysis of Credibility

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    It is now widely accepted that the techniques of null hypothesis significance testing (NHST) are routinely misused and misinterpreted by researchers seeking insight from data. There is, however, no consensus on acceptable alternatives, leaving researchers with little choice but to continue using NHST, regardless of its failings. I examine the potential for the Analysis of Credibility (AnCred) to resolve this impasse. Using real-life examples, I assess the ability of AnCred to provide researchers with a simple but robust framework for assessing study findings that goes beyond the standard dichotomy of statistical significance/nonsignificance. By extracting more insight from standard summary statistics while offering more protection against inferential fallacies, AnCred may encourage researchers to move toward the post p < 0.05 era
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