1,884 research outputs found
Book Review
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
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
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
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
This essay examines the concept of childrenâs 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
childrenâs 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 âante-autobiographyâ 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 â A Danish clinical registry of people with chronic back pain
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
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
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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