144 research outputs found

    Technologies to Support Authentication in Higher Education:A Study for the UK Joint Information Systems Committee, August 21th, 1996

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    This report provides a short and limited study, commissioned by JISC, of the technologies available to support authentication, reviews the needs expressed by a set of people contacted for the study, and provides the beginnings of a road-map on how a National system might be established.First a brief overview of the fundamentals of Security technology is provided. As part of the study, we were asked to consult a number of people - particularly from the set of those supported under the JISC Electronic Library initiative. These were supplemented by some people at UKERNA and in Information Services departments in the universities. We present our impressions of the requirements envisioned by the people consulted, and their proposed solutions; with very few exceptions, the needs expressed were very limited, and the solutions limited to specific applications. This reflects, we believe, more the selection of the people consulted, than the true needs of the area. It was also coloured, in our view, by the fact that there was no indication that any finance for a wider initiative might be available.A more detailed review of the current methods of authentication, the needs and the status of different applications follows. This includes a brief discussion about the Standards being developed in the Internet Engineering Task Force in conjunction with the wider deployment of the Internet and the status of infrastructure standardisation and deployment. We consider also a number of applications: electronic mail, the World Wide Web, remote log-in, document security, multimedia conferencing, directories, general network facilities and electronic commerce. A brief discussion of a number of ancillary technical and legal issues follow: this includes smart-cards, directory systems and key escrow. The existence of legal considerations is indicated, but little argument is developed other than the appending of proposed Government legislation. As a final section, we start on a Road Map of how we might proceed to a National authentication infrastructure for Higher Education. We believe that such a system should be distributed in nature, and could well leverage on the investment already made in an X.500 distributed directory system. It is clear that the current technology would need considerable updating; much broader involvement must be achieved from other sectors of the universities for such an initiative to have broad impact. We mention some of the measures that should be undertaken to enable a successful broader applicability. Based on the existence of a National directory system, we then propose a National authentication infrastructure by proposing a system of Certification Authorities, distributed registration and update, and the retention of the certificates in the National directory system. We propose that existing projects in secure E-mail and electronic libraries be asked how they might be modified if such an infrastructure was developed.A substantial distributed infrastructure for authentication could have implication well beyond the university sector. For this reason, it may be possible to co-fund the development and many of the earlier trials from sources outside JISC. We propose that we explore avenues of co-funding both from the British Foresight Programme and from the European Union Telematics programme.<br/

    Charge control and mobility in AlGaN/GaN transistors: Experimental and theoretical studies

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    In this article we report on two dimensional sheet charge and mobility in GaN/AlGaN heterostructure field effect transistors. Both experimental and theoretical results are presented. Experimental results are reported on samples grown by metal organic chemical vapor deposition (MOCVD) and molecular beam epitaxy (MBE). Theoretical studies are done to examine how spontaneous polarization and piezoelectric effect control the sheet charge density. The studies also focus on how interface roughness, aluminum mole fraction in the barrier and phonon scattering influence mobility. We find that interface roughness is a dominant source of scattering in the samples reported. Due to the variation in growth techniques we find that the MBE samples have a smoother interface compared to the MOCVD samples. By carefully fitting the experimental data we present results on interface roughness parameters for MBE and MOCVD samples. © 2000 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70927/2/JAPIAU-87-11-7981-1.pd

    The impact of General Dental Council registration and continuing professional development on UK dental care professionals:(1) dental nurses.

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    Objective To investigate the impact of GDC registration and mandatory CPD on dental nurses’ views, job satisfaction and intention to leave. Design Postal/online survey, conducted in parallel with a survey of dental technicians. Setting UK private and NHS practices, community services, dental hospitals. Subjects and methods Representative sample of General Dental Council registrants. Main outcome measures Job satisfaction; intention to leave profession (dependent variable in regression analysis). Results Eleven were ineligible (left profession, moved abroad); 267 (44% of those eligible) responded, all female. Respondents’ mean age was 38.2 years (sd 10.74). The general principle of registration was endorsed by 67%, and compulsory registration by 51%, but the fee level by only 6%. Most nurses did not feel that registration had affected their view of dental nursing as a career (56%), their role (74%) or status (86%) within the dental team, or that CPD helped them to do their job better (76%). Fiftly-six percent were not satisfied with their job, and 22% intended to leave the profession. Intention to leave was predicted by younger age and greater dissatisfaction with physical working conditions and opportunities to progress. Conclusions Widely held criticisms regarding the costs and relevance of registration and CPD coupled with a potentially high level of attrition from the profession suggest a review of the fee and salary structure and greater financial support for CPD is warranted

    Normal modes and discovery of high-order cross-frequencies in the DBV white dwarf GD 358

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    We present a detailed mode identification performed on the 1994 Whole Earth Telescope (WET) run on GD 358. The results are compared with that obtained for the same star from the 1990 WET data. The two temporal spectra show very few qualitative differences, although amplitude changes are seen in most modes, including the disappearance of the mode identified as k=14 in the 1990 data. The excellent coverage and signal-to-noise ratio obtained during the 1994 run lead to the secure identification of combination frequencies up to fourth order, i.e. peaks that are sums or differences of up to four parent frequencies, including a virtually complete set of second-order frequencies, as expected from harmonic distortion. We show how the third-order frequencies are expected to affect the triplet structure of the normal modes by back-interacting with them. Finally, a search for â„“=2 modes was unsuccessful, not verifying the suspicion that such modes had been uncovered in the 1990 data set

    REFERQUAL: A pilot study of a new service quality assessment instrument in the GP Exercise Referral scheme setting

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    Background The development of an instrument accurately assessing service quality in the GP Exercise Referral Scheme (ERS) industry could potentially inform scheme organisers of the factors that affect adherence rates leading to the implementation of strategic interventions aimed at reducing client drop-out. Methods A modified version of the SERVQUAL instrument was designed for use in the ERS setting and subsequently piloted amongst 27 ERS clients. Results Test re-test correlations were calculated via Pearson's 'r' or Spearman's 'rho', depending on whether the variables were Normally Distributed, to show a significant (mean r = 0.957, SD = 0.02, p < 0.05; mean rho = 0.934, SD = 0.03, p < 0.05) relationship between all items within the questionnaire. In addition, satisfactory internal consistency was demonstrated via Cronbach's 'α'. Furthermore, clients responded favourably towards the usability, wording and applicability of the instrument's items. Conclusion REFERQUAL is considered to represent promise as a suitable tool for future evaluation of service quality within the ERS community. Future research should further assess the validity and reliability of this instrument through the use of a confirmatory factor analysis to scrutinise the proposed dimensional structure

    Whole Earth Telescope observations of the hot helium atmosphere pulsating white dwarf EC 20058-5234

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    We present the analysis of a total of 177h of high-quality optical time-series photometry of the helium atmosphere pulsating white dwarf (DBV) EC 20058-5234. The bulk of the observations (135h) were obtained during a WET campaign (XCOV15) in July 1997 that featured coordinated observing from 4 southern observatory sites over an 8-day period. The remaining data (42h) were obtained in June 2004 at Mt John Observatory in NZ over a one-week observing period. This work significantly extends the discovery observations of this low-amplitude (few percent) pulsator by increasing the number of detected frequencies from 8 to 18, and employs a simulation procedure to confirm the reality of these frequencies to a high level of significance (1 in 1000). The nature of the observed pulsation spectrum precludes identification of unique pulsation mode properties using any clearly discernable trends. However, we have used a global modelling procedure employing genetic algorithm techniques to identify the n, l values of 8 pulsation modes, and thereby obtain asteroseismic measurements of several model parameters, including the stellar mass (0.55 M_sun) and T_eff (~28200 K). These values are consistent with those derived from published spectral fitting: T_eff ~ 28400 K and log g ~ 7.86. We also present persuasive evidence from apparent rotational mode splitting for two of the modes that indicates this compact object is a relatively rapid rotator with a period of 2h. In direct analogy with the corresponding properties of the hydrogen (DAV) atmosphere pulsators, the stable low-amplitude pulsation behaviour of EC 20058 is entirely consistent with its inferred effective temperature, which indicates it is close to the blue edge of the DBV instability strip. (abridged)Comment: 19 pages, 8 figures, 5 tables, MNRAS accepte
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