81,561 research outputs found
Challenging Assumptions about IT skills in Higher Education
This paper challenges the idea of 'the digital native' and the subsequent assumption of digital literacy skills amongst higher education students. It offers clear evidence that current student populations come from a wider range of backgrounds than the theory allows for and that the younger student population is also more complex with varying levels of digital literacy experience. It argues that treating students as a homogenous mass is problematic and challenges the idea that generic technology skills are instantly transferable to academic study. The paper concludes with a warning that we are letting down some of our students by the âInformation Technology (IT) barrierâ within higher education and that we should be focusing on identification of Information Technology (IT) need and IT skills acquisition support rather than assuming it is something students can âpick up as they go alongâ. This will only happen once IT is given the status of a core academic skill along with maths, information literacy and academic communication
Precision Optical Measurements and Fundamental Physical Constants
A brief overview is given on precision determinations of values of the
fundamental physical constants and the search for their variation with time by
means of precision spectroscopy in the optical domain
ARES+MOOG - a practical overview of an EW method to derive stellar parameters
The goal of this document is to describe the important practical aspects in
the use of an Equivalent Width (EW) method for the derivation of spectroscopic
stellar parameters. A general description of the fundamental steps composing
any EW method is given, together with possible differences that may be found in
different methods used in the literature. Then ARES+MOOG is then used as an
example where each step of the method is described in detail. A special focus
is given for the specific steps of this method, namely the use of a
differential analysis to define the atomic data for the adopted line list, the
automatic EW determinations, and the way to find the best parameters at the end
of the procedure. Finally, a practical tutorial is given, where we focus on
simple exercises useful to illustrate and explain the dependence of the
abundances with the assumed stellar parameters. The interdependences are
described and a clear procedure is given to find the "final" stellar
parameters.Comment: 15 pages, 4 figures, accepted for publication as a chapter in
"Determination of Atmospheric Parameters of B, A, F and G Type Stars",
Springer (2014), eds. E. Niemczura, B. Smalley, W. Pyc
Implementation of Quantum Gates via Optimal Control
Starting with the basic control system model often employed in NMR pulse
design, we derive more realistic control system models taking into account
effects such as off-resonant excitation for systems with fixed inter-qubit
coupling controlled by globally applied electromagnetic fields, as well as for
systems controlled by a combination of a global fields and local control
electrodes. For both models optimal control is used to find controls that
implement a set of two- and three-qubit gates with fidelity greater than
99.99%. While in some cases the optimal pulses obtained appear to be
surprisingly simple and experimentally realistic, the results also show that
the "optimal" pulses obtained in other cases are experimentally infeasible, and
more sophisticated parametrization of the control fields and numerical
algorithms are needed.Comment: 10 pages, 4 figure
A comparison between tests for changes in the adjustment coefficients in cointegrated systems
In this paper we examine several approaches to detecting changes in the adjustment coefficients in cointegrated VARs. We adopt recursive and rolling techniques as mis-specification tests for the detection of non-constancy and the estimation of the breakpoints. We find that inspection of the recursive eigenvalues is not useful to detect a break in the adjustment coefficients, whilst recursive estimation of the coefficients can only indicate non-constancy, but not the exact breakpoint. Rolling estimation is found to perform better in detecting non-constancy in the parameters and their true value after the breakpoint. However, it only detects a region where the break is likely to occur. To overcome the drawbacks of these techniques, we use an OLS-based sequential test. To assess its performance, we derive its critical values for different sample sizes. Monte Carlo evidence shows that the test has reasonably good power even in moderately sized samples and that it can be used as a graphical device, as it shows a kink at the breakpoint. As a benchmark we use the Kalman filter, of which we analyse the performance on the same data generating processes (DGP)
NdYAG laser treatment of a glomus tympanicum tumour
Glomus tympanicum tumours are highly vascular tumours of the middle ear. Their removal by conventional surgical methods requires an extensive procedure in many cases, often with ossicular disarticulation to allow adequate exposure prior to the 'chaotic' and haemorrhagic event of tumour removal. This paper reports on the use of an NdYAG laser in a case of a large glomus tympanicum tumour. The laser facilitated a transcanal approach, avoided ossicular disarticulation and allowed accurate and almost bloodless ablation of the entire tumour.The NdYAG laser appears to be a very useful treatment modality in the management of these highly vascular tumours. Care should be taken to avoid accidental energy transmission to the cochlea
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