27,648 research outputs found
Safety and the flying doctor
Interest, curiosity, or dismay—which feeling predominates when we learn from BBC Newsnight that our NHS employs doctors who commute from Poland to cover the out of hours duties that local GPs are unable to work because they are too tired at night? Is it interest in an innovative solution for modern pan-European healthcare provision, curiosity in discovering huge variations in the standard of living across the medical profession in an open Europe, or dismay that the government’s emphasis, that healthcare practice should be based on the best scientific evidence, is little more than lip service?
Working continuously for a long time, particularly at night, increases the risk of making errors and causing injury, which is why many professions limit the number of hours of continuous duty. These risks also apply to the medical profession: tired doctors make mistakes that harm patients (N Engl J Med 2004;351:1838-48) and themselve
Syllable classification using static matrices and prosodic features
In this paper we explore the usefulness of prosodic features for
syllable classification. In order to do this, we represent the
syllable as a static analysis unit such that its acoustic-temporal
dynamics could be merged into a set of features that the SVM
classifier will consider as a whole. In the first part of our
experiment we used MFCC as features for classification,
obtaining a maximum accuracy of 86.66%. The second part of
our study tests whether the prosodic information is
complementary to the cepstral information for syllable
classification. The results obtained show that combining the
two types of information does improve the classification, but
further analysis is necessary for a more successful
combination of the two types of features
On the spectral functions of scalar mesons
In this work we study the spectral functions of scalar mesons in one- and
two-channel cases. When the propagators satisfy the K\"allen-Lehman
representation a normalized spectral function is obtained, allowing to take
into account finite-width effects in the evaluation of decay rates. In the
one-channel case, suitable to the light sigma and k mesons, the spectral
function can deviate consistently from a Breit-Wigner shape. In the two-channel
case with one subthreshold channel the evaluated spectral function is well
approximated by a Flatte' distribution; when applying the study to the a_0(980)
and f_0(980) mesons the tree-level forbidden KK decay is analysed.Comment: 13 pages, 7 figure
Theory and computation of higher gradient elasticity theories based on action principles
In continuum mechanics, there exists a unique theory for elasticity, which includes the first gradient of displacement. The corresponding generalization of elasticity is referred to as strain gradient elasticity or higher gradient theories, where the second and higher gradients of displacement are involved. Unfortunately, there is a lack of consensus among scientists how to achieve the generalization. Various suggestions were made, in order to compare or even verify these, we need a generic computational tool. In this paper, we follow an unusual but quite convenient way of formulation based on action principles. First, in order to present its benefits, we start with the action principle leading to the well-known form of elasticity theory and present a variational formulation in order to obtain a weak form. Second, we generalize elasticity and point out, in which term the suggested formalism differs. By using the same approach, we obtain a weak form for strain gradient elasticity. The weak forms for elasticity and for strain gradient elasticity are solved numerically by using open-source packages—by using the finite element method in space and finite difference method in time. We present some applications from elasticity as well as strain gradient elasticity and simulate the so-called size effect
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