81,049 research outputs found

    Challenging Assumptions about IT skills in Higher Education

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    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 ‘Information Technology (IT) barrier’ 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 ‘pick up as they go along’. 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

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    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

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    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

    Efficiency of low power audio amplifiers and loudspeakers

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    Implementation of Quantum Gates via Optimal Control

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    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

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    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)

    Propagation measurements to support third generation mobile radio network planning

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    NdYAG laser treatment of a glomus tympanicum tumour

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    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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