75,835 research outputs found

    The Great Case of The Canal vs. The Railroad - 4 Gill & Johnson 1 (1832)

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    Annular wing

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    An annular wing particularly suited for use in supporting in flight an aircraft characterized by the absence of directional stabilizing surfaces is described. The wing comprises a rigid annular body of a substantially uniformly symmetrical configuration characterized by an annular positive lifting surface and cord line coincident with the segment of a line radiating along the surface of an inverted truncated cone. A decalage is established for the leading and trailing semicircular portions of the body, relative to instantaneous line of flight, and a dihedral for the laterally opposed semicircular portions of the body, relative to the line of flight. The direction of flight and climb angle or glide slope angle are established by selectively positioning the center of gravity of the wing ahead of the aerodynamic center along the radius coincident with an axis for a selected line of flight

    Mooring and ground handling rigid airships

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    The problems of mooring and ground handling rigid airships are discussed. A brief history of Mooring and Ground Handling Rigid Airships from July 2, 1900 through September 1, 1939 is included. Also a brief history of ground handling developments with large U. S. Navy nonrigid airships between September 1, 1939 and August 31, 1962 is included wherein developed equipment and techniques appear applicable to future large rigid airships. Finally recommendations are made pertaining to equipment and procedures which appear desirable and feasible for future rigid airship programs

    Global Continua of Positive Equilibria for some Quasilinear Parabolic Equation with a Nonlocal Initial Condition

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    This paper is concerned with a quaslinear parabolic equation including a nonlinear nonlocal initial condition. The problem arises as equilibrium equation in population dynamics with nonlinear diffusion. We make use of global bifurcation theory to prove existence of an unbounded continuum of positive solutions

    On the numerical evaluation of the maximum-likelihood estimate of mixture means

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    Starting with an n-dimensional variable whose density function is a convex combination of normal densities, the equations for a maximum-likelihood estimate are obtained. Iterative procedures for obtaining solutions to the likelihood equations are discussed along with conditions for local convergence

    Some qualitative remarks on the variation of the probability of error

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    The qualitative behavior of the probability of misclassifying observations from two normally distributed populations as the classification regions are varied in a prescribed way is described in order to provide a preliminary generalization of the results obtained by Walton for the case of normally distributed observations with varying a priori probabilities

    The mean-square error optimal linear discriminant function and its application to incomplete data vectors

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    In many pattern recognition problems, data vectors are classified although one or more of the data vector elements are missing. This problem occurs in remote sensing when the ground is obscured by clouds. Optimal linear discrimination procedures for classifying imcomplete data vectors are discussed

    Profile of allergy-related articles in the primary academic publication for UK General Practitioners

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    Background: Concern is often expressed about primary health care professionals’ lack of knowledge about allergies, particularly diagnostic testing and the management of atopic disorders. Limited training opportunities in allergy have been documented in both undergraduate and postgraduate education. The British Journal of General Practice is the leading UK-based Family Practice journal, it has a strong clinical focus. The BJGP was established in 1953. It is a high quality journal and is the world’s 2nd most highly cited journal of general practice and primary care. Methods: Keyword search of bjgp.org. Terms used were ‘allergy’, ‘allergies’, ‘allergic’, ‘rhinitis’, ‘urticaria’, ‘eczema’, ‘angioedema’. All titles and articles from 1953 to 2013 were searched. Full copies of relevant publications were downloaded and variables extracted, including title, year of publication, type of article, clinical focus. As a comparator a similar search was conducted for articles about asthma using the search term ‘asthma’. Results: 41 allergy-related articles were identified in the 60 years since the journal was launched. In the same time period there were 147 articles about asthma. In 31 of the 60 years reviewed there were no articles at all about any allergy-related topic. The focus of the articles published were eczema (6), food allergy (6), rhinoconjunctivitis (5), anaphylaxis (4), urticaria (1). There were no articles on angioedema. Some articles addressed multiple atopic disorders, eg ‘Allergic diseases in the elderly’ (1968), ‘Allergic disorders amongst horticultural, agricultural and forestry workers’ [letter] (1965). Conclusions: Allergy has a low profile in the British Journal of General Practice. This low profile persists despite the increasing prevalence of atopic disorders and major national reports highlighting the need for better care of the allergic patient in primary care. Our exploratory study highlights a missed opportunity to educate and inform General Practitioners about allergy through this widely circulated journal. Further work is needed to understand better why so few articles on allergy are published in the BJGP. If the paucity of publications reflects the number of articles submitted then BSACI members interested in informing and improving allergy management in General Practice should include the BJGP on their list of target journals. Where next: To share these observations with the Editor of the BJGP to understand whether they reflect editorial policy or lack of submissions from clinicians and researchers with expertise in allergy. To work with the BJGP to identify collaborative initiatives to address the serious mismatch between the prevalence of allergy in the clinical consultation and the number of allergy- related articles in the literature for GPs

    The numerical evaluation of maximum-likelihood estimates of the parameters for a mixture of normal distributions from partially identified samples

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    Likelihood equations determined by the two types of samples which are necessary conditions for a maximum-likelihood estimate are considered. These equations, suggest certain successive-approximations iterative procedures for obtaining maximum-likelihood estimates. These are generalized steepest ascent (deflected gradient) procedures. It is shown that, with probability 1 as N sub 0 approaches infinity (regardless of the relative sizes of N sub 0 and N sub 1, i=1,...,m), these procedures converge locally to the strongly consistent maximum-likelihood estimates whenever the step size is between 0 and 2. Furthermore, the value of the step size which yields optimal local convergence rates is bounded from below by a number which always lies between 1 and 2
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