521 research outputs found

    Technological and Organisational Readiness in the Age of Data-Driven Decision Making : A Manufacturing Perspective

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    This paper is concerned with the changes brought about by digital transformation, which impact society and businesses as well as individuals. These changes also influence manufacturing organisations as decision-making processes are automated and increasingly driven by data analysis. The aim of this research paper is to discuss and analyse technological and organisational readiness in manufacturing. The main areas of focus are Big Data Analytics, Artificial Intelligence in collaboration processes, and the role of the human in future manufacturing organisations

    Markov Chain Monte Carlo joint analysis of Chandra X-ray imaging spectroscopy and Sunyaev-Zeldovich Effect data

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    X-ray and Sunyaev-Zeldovich Effect data can be combined to determine the distance to galaxy clusters. High-resolution X-ray data are now available from the Chandra Observatory, which provides both spatial and spectral information, and Sunyaev-Zeldovich Effect data were obtained from the BIMA and OVRO arrays. We introduce a Markov chain Monte Carlo procedure for the joint analysis of X-ray and Sunyaev-Zeldovich Effect data. The advantages of this method are the high computational efficiency and the ability to measure simultaneously the probability distribution of all parameters of interest, such as the spatial and spectral properties of the cluster gas and also for derivative quantities such as the distance to the cluster. We demonstrate this technique by applying it to the Chandra X-ray data and the OVRO radio data for the galaxy cluster Abell 611. Comparisons with traditional likelihood-ratio methods reveal the robustness of the method. This method will be used in follow-up papers to determine the distances to a large sample of galaxy clusters.Comment: ApJ accepted, scheduled for ApJ 10 October 2004, v614 issue. Title changed, added more convergence diagnostic tests, Figure 7 converted to lower resolution for easier download, other minor change

    X-ray and Sunyaev-Zel'dovich Effect Measurements of the Gas Mass Fraction in Galaxy Clusters

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    We present gas mass fractions of 38 massive galaxy clusters spanning redshifts from 0.14 to 0.89, derived from Chandra X-ray data and OVRO/BIMA interferometric Sunyaev-Zel'dovich Effect measurements. We use three models for the gas distribution: (1) an isothermal beta-model fit jointly to the X-ray data at radii beyond 100 kpc and to all of the SZE data,(2) a non-isothermal double beta-model fit jointly to all of the X-ray and SZE data, and (3) an isothermal beta-model fit only to the SZE spatial data. We show that the simple isothermal model well characterizes the intracluster medium (ICM) outside of the cluster core in clusters with a wide range of morphological properties. The X-ray and SZE determinations of mean gas mass fractions for the 100 kpc-cut isothermal beta-model are fgas(X-ray)=0.110 +0.003-0.003 +0.006-0.018 and fgas(SZE)=0.116 +0.005-0.005 +0.009-0.026, where uncertainties are statistical followed by systematic at 68% confidence. For the non-isothermal double beta-model, fgas(X-ray)=0.119 +0.003-0.003 +0.007-0.014 and fgas(SZE)=0.121 +0.005-0.005 +0.009-0.016. For the SZE-only model, fgas(SZE)=0.120 +0.009-0.009 +0.009-0.027. Our results indicate that the ratio of the gas mass fraction within r2500 to the cosmic baryon fraction is 0.68 +0.10-0.16 where the range includes statistical and systematic uncertainties. By assuming that cluster gas mass fractions are independent of redshift, we find that the results are in agreement with standard LambdaCDM cosmology and are inconsistent with a flat matter dominated universe.Comment: ApJ, submitted. 47 pages, 5 figures, 8 table

    Swift XRT Observations of the Possible Dark Galaxy VIRGOHI 21

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    \swift \xrt observations of the \hi line source \VV were performed on April 22 and April 26, 2008 for a total exposure time of 9.2ks. This is the first pointed X-ray observation of \VV, a putative dark galaxy in the Virgo cluster, and no photons were detected from this source. The non-detection of extended X-ray emission within the angular extent of the \hi source corresponds to a 99% confidence upper limit of 2.1×10142.1 \times 10^{-14}\ergcms in the 0.3--2.0 keV band. The equivalent upper limit to the amount of diffuse hot gas associated with \VV is in the range 4×1072×1084\times 10^{7} - 2 \times 10^8 \msun for a hot gas temperature between 0.1 and 1 keV. The non-detection also corresponds to a 99%-confidence upper limit on the flux from a point-like source of 8×10158\times 10^{-15}\ergcms in the 0.3--2.0 keV band. We discuss the constraints on the nature of \VV imposed by these observations and the theoretical implications of these results.Comment: ApJL in press, accepted versio

    Results from the Project 8 phase-1 cyclotron radiation emission spectroscopy detector

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    The Project 8 collaboration seeks to measure the absolute neutrino mass scale by means of precision spectroscopy of the beta decay of tritium. Our technique, cyclotron radiation emission spectroscopy, measures the frequency of the radiation emitted by electrons produced by decays in an ambient magnetic field. Because the cyclotron frequency is inversely proportional to the electron's Lorentz factor, this is also a measurement of the electron's energy. In order to demonstrate the viability of this technique, we have assembled and successfully operated a prototype system, which uses a rectangular waveguide to collect the cyclotron radiation from internal conversion electrons emitted from a gaseous 83m^{83m}Kr source. Here we present the main design aspects of the first phase prototype, which was operated during parts of 2014 and 2015. We will also discuss the procedures used to analyze these data, along with the features which have been observed and the performance achieved to date.Comment: 3 pages; 2 figures; Proceedings of Neutrino 2016, XXVII International Conference on Neutrino Physics and Astrophysics, 4-9 July 2016, London, U

    Project 8 Phase III Design Concept

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    We present a working concept for Phase III of the Project 8 experiment, aiming to achieve a neutrino mass sensitivity of 2 eV2~\mathrm{eV} (90 %90~\% C.L.) using a large volume of molecular tritium and a phased antenna array. The detection system is discussed in detail.Comment: 3 pages, 3 figures, Proceedings of Neutrino 2016, XXVII International Conference on Neutrino Physics and Astrophysics, 4-9 July 2016, London, U

    ADMX-Orpheus First Search for 70 μ\mueV Dark Photon Dark Matter: Detailed Design, Operations, and Analysis

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    Dark matter makes up 85% of the matter in the universe and 27% of its energy density, but we don't know what comprises dark matter. It is possible that dark matter may be composed of either axions or dark photons, both of which can be detected using an ultra-sensitive microwave cavity known as a haloscope. The haloscope employed by ADMX consists of a cylindrical cavity operating at the TM010_{010} mode and is sensitive to the QCD axion with masses of few μ\mueV. However, this haloscope design becomes challenging to implement for higher masses. This is because higher masses require smaller-diameter cavities, consequently reducing the detection volume which diminishes the detected signal power. ADMX-Orpheus mitigates this issue by operating a tunable, dielectrically-loaded cavity at a higher-order mode, allowing the detection volume to remain large. This paper describes the design, operation, analysis, and results of the inaugural ADMX-Orpheus dark photon search between 65.5 μ\mueV (15.8 GHz) and 69.3 μ\mueV (16.8 GHz), as well as future directions for axion searches and for exploring more parameter space.Comment: 21 pages, 29 figures. To be submitted to Physical Review D. arXiv admin note: substantial text overlap with arXiv:2112.0454
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