1,884 research outputs found

    Book Review

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    Review of: MARY R. ENGLISH, SITING LOW-LEVEL RADIOACTIVE WASTE DISPOSAL FACILITIES: THE PUBLIC POLICY DILEMMA. (Quorum Books 1992) [278 pp.], Appendices, index, introduction, references. LC-91-42774; ISBN 0-89930-560-1. [$49.95 cloth. One Madison Avenue, New York NY 10010.

    Large N lattice QCD and its extended strong-weak connection to the hypersphere

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    We calculate an effective Polyakov line action of QCD at large Nc and large Nf from a combined lattice strong coupling and hopping expansion working to second order in both, where the order is defined by the number of windings in the Polyakov line. We compare with the action, truncated at the same order, of continuum QCD on S^1 x S^d at weak coupling from one loop perturbation theory, and find that a large Nc correspondence of equations of motion found in \cite{Hollowood:2012nr} at leading order, can be extended to the next order. Throughout the paper, we review the background necessary for computing higher order corrections to the lattice effective action, in order to make higher order comparisons more straightforward.Comment: 33 pages, 7 figure

    Calculating the chiral condensate diagrammatically at strong coupling

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    We calculate the chiral condensate of QCD at infinite coupling as a function of the number of fundamental fermion flavours using a lattice diagrammatic approach inspired by recent work of Tomboulis, and other work from the 80's. We outline the approach where the diagrams are formed by combining a truncated number of sub-diagram types in all possible ways. Our results show evidence of convergence and agreement with simulation results at small Nf. However, contrary to recent simulation results, we do not observe a transition at a critical value of Nf. We further present preliminary results for the chiral condensate of QCD with symmetric or adjoint representation fermions at infinite coupling as a function of Nf for Nc = 3. In general, there are sources of error in this approach associated with miscounting of overlapping diagrams, and over-counting of diagrams due to symmetries. These are further elaborated upon in a longer paper.Comment: presented at the 32nd International Symposium on Lattice Field Theory (Lattice 2014), 23-28 June 2014, New York, NY, US

    Calculating the chiral condensate of QCD at infinite coupling using a generalised lattice diagrammatic approach

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    We develop a lattice diagrammatic technique for calculating the chiral condensate of QCD at infinite coupling inspired by recent work of Tomboulis and earlier work from the 80's. The technique involves calculating the contribution of gauge link diagrams formed from all possible combinations of a number of sub-diagram types. This is achieved by performing a resummation, using a truncated number of sub-diagram types. We show how to calculate the relevant sub-diagrams, including a new technique for evaluating group integrals with arbitrary number of gauge link elements, using Young Projectors. Including up to four different diagram types we calculate the chiral condensate as a function of Nf, and show that two real solutions result, which are non-zero for all integer Nf. We analyse these solutions and find signs of convergence of the expansion at small Nf. We discuss sources of error associated with this approach in detail and implement a technique to reduce over-counting of diagrams.Comment: 47 pages, including 2 appendices, 10 plot

    Ante-Autobiography and the Archive of Childhood

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    This essay examines the concept of children’s autobiography via several autobiographical extracts written by the author as a child. Although only a small proportion of people will compose and publish a full-length autobiography, almost everyone will, inadvertently, produce an archive of the self, made from public records and private documents. Here, such works are seen as providing access to writing both about and by children. The essay explores the ethics and poetics of children’s writing via the key debates in life writing; in particular, the dynamic relationship between adults and children, both as distinct stages of life and dual parts of one autobiographical identity. The term “ante-autobiography” is coined to refer to these texts which come before or instead of a full-length narrative. They are not read as less than or inadequate versions of autobiography, but rather as transgressive and challenging to chronological notions of the genre

    SpineData – A Danish clinical registry of people with chronic back pain

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    Background: Large-scale clinical registries are increasingly recognized as important resources for quality assurance and research to inform clinical decision-making and health policy. We established a clinical registry (SpineData) in a conservative care setting where more than 10,000 new cases of spinal pain are assessed each year. This paper describes the SpineData registry, summarizes the characteristics of its clinical population and data, and signals the availability of these data as a resource for collaborative research projects. Methods: The SpineData registry is an Internet-based system that captures patient data electronically at the point of clinical contact. The setting is the government-funded Medical Department of the Spine Centre of Southern Denmark, Hospital Lillebaelt, where patients receive a multidisciplinary assessment of their chronic spinal pain. Results: Started in 2011, the database by early 2015 contained information on more than 36,300 baseline episodes of patient care, plus the available 6-month and 12-month follow-up data for these episodes. The baseline questionnaire completion rate has been 93%; 79% of people were presenting with low back pain as their main complaint, 6% with mid-back pain, and 15% with neck pain. Collectively, across the body regions and measurement time points, there are approximately 1,980 patient-related variables in the database across a broad range of biopsychosocial factors. To date, 36 research projects have used data from the SpineData registry, including collaborations with researchers from Denmark, Australia, the United Kingdom, and Brazil. Conclusion: We described the aims, development, structure, and content of the SpineData registry, and what is known about any attrition bias and cluster effects in the data. For epidemiology research, these data can be linked, at an individual patient level, to the Danish population-based registries and the national spinal surgery registry. SpineData also has potential for the conduct of cohort multiple randomized controlled trials. Collaborations with other researchers are welcome

    Design of a soft gamma-ray focusing telescope for the study of nuclear lines

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    We have studied the design of astronomical multilayer telescopes optimized for performance from 5 to 200 keV. This region of the spectrum contains important nuclear lines that are observable in supernovae and their remnants. The study of these lines can help to differentiate currently competing theories of supernova explosion. Our telescope design will enable us to measure the spectral lines of isotopes such as Ni-56 in Type Ia supernovae and Ti-44 in core-collapse remnants, as well as to observe active galactic nuclei at gamma-ray energies. We considered the performances of multilayers of various material pairs, including W/Si, Pt/C and Ni93V7/Si, as employed in conical-approximation Wolter I optics. We experimented with dividing the energy band of interest into several sections, and optimizing different groups of mirror shells within a single telescope for each smaller energy band. Different material pairs are also used for different energy bands, in order to obtain a higher overall performance. We also consider the significance of the energy bandwidth on the effectiveness of Joensen's parametrization of the multilayer thickness profile, and on the mirror performance within the band

    Languages' impact on emotional classification methods

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    There is currently a lack of research concerning whether Emotional Classification (EC) research on a language is applicable to other languages. If this is the case then we can greatly reduce the amount of research needed for different languages. Therefore, we propose a framework to answer the following null hypothesis: The change in classification accuracy for Emotional Classification caused by changing a single preprocessor or classifier is independent of the target language within a significance level of p = 0.05. We test this hypothesis using an English and a Danish data set, and the classification algorithms: Support-Vector Machine, Naive Bayes, and Random Forest. From our statistical test, we got a p-value of 0.12852 and could therefore not reject our hypothesis. Thus, our hypothesis could still be true. More research is therefore needed within the field of cross-language EC in order to benefit EC for different languages
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