19,495 research outputs found
Plugging the âPhishingâ Hole: Legislation Versus Technology
This iBrief analyzes the Anti-Phishing Act of 2005, legislation aimed at curbing the problem of phishing. Phishing is the sending of fraudulent emails which appear to be from legitimate businesses and thereby fooling the recipients into divulging personal information such as credit card numbers. While this legislation may provide some assistance in the fight against phishing, it is limited by the global nature of the Internet and the ease with which phishers can hide and avoid judgments. This iBrief therefore concludes that although the Anti-Phishing Act can play a supporting role in the battle, technological solutions are the most effective means of reducing or eliminating phishing attacks
Study of noise reduction characteristics of composite fiber-reinforced panels, interior panel configurations, and the application of the tuned damper concept
The application of fiber reinforced composite materials, such as graphite epoxy and Kevlar, for secondary or primary structures developing in the commercial airplane industry was investigated. A composite panel program was initiated to study the effects of some of the parameters that affect noise reduction of these panels. The fiber materials and the ply orientation were chosen to be variables in the test program. It was found that increasing the damping characteristics of a structural panel will reduce the vibration amplitudes at resonant frequencies with attendant reductions in sound reduction. Test results for a dynamic absorber, a tuned damper, are presented and evaluated
An economics systems analysis of land mobile radio telephone services
The economic interaction of the terrestrial and satellite systems is considered. Parametric equations are formulated to allow examination of necessary user thresholds and growth rates as a function of system costs. Conversely, first order allowable systems costs are found as a function of user thresholds and growth rates. Transitions between satellite and terrestrial service systems are examined. User growth rate density (user/year/sq km) is shown to be a key parameter in the analysis of systems compatibility. The concept of system design matching the price/demand curves is introduced and examples are given. The role of satellite systems is critically examined and the economic conditions necessary for the introduction of satellite service are identified
Module categories for group algebras over commutative rings
We develop a suitable version of the stable module category of a finite group
G over an arbitrary commutative ring k. The purpose of the construction is to
produce a compactly generated triangulated category whose compact objects are
the finitely presented kG-modules. The main idea is to form a localisation of
the usual version of the stable module category with respect to the filtered
colimits of weakly injective modules. There is also an analogous version of the
homotopy category of weakly injective kG-modules and a recollement relating the
stable category, the homotopy category, and the derived category of kG-modules.Comment: Appendix by Greg Stevenso
Deciphering the Atmospheric Composition of WASP-12b: A Comprehensive Analysis of its Dayside Emission
WASP-12b was the first planet reported to have a carbon-to-oxygen ratio (C/O)
greater than one in its dayside atmosphere. However, recent work to further
characterize its atmosphere and confirm its composition has led to incompatible
measurements and divergent conclusions. Additionally, the recent discovery of
stellar binary companions ~1" from WASP-12 further complicates the analyses and
subsequent interpretations. We present a uniform analysis of all available
Hubble and Spitzer Space Telescope secondary-eclipse data, including
previously-unpublished Spitzer measurements at 3.6 and 4.5 microns. The primary
controversy in the literature has centered on the value and interpretation of
the eclipse depth at 4.5 microns. Our new measurements and analyses confirm the
shallow eclipse depth in this channel, as first reported by Campo and
collaborators and used by Madhusudhan and collaborators to infer a carbon-rich
composition. To explain WASP-12b's observed dayside emission spectrum, we
implemented several recent retrieval approaches. We find that when we exclude
absorption due to C2H2 and HCN, which are not universally considered in the
literature, our models require implausibly large atmospheric CO2 abundances,
regardless of the C/O. By including C2H2 and HCN in our models, we find that a
physically-plausible carbon-rich solution achieves the best fit to the
available photometric and spectroscopic data. In comparison, the best-fit
oxygen-rich models have abundances that are inconsistent with the chemical
equilibrium expectations for hydrogen-dominated atmospheres and are 670 times
less probable. Our best-fit solution is also 7.3*10^{6} times more probable
than an isothermal blackbody model.Comment: 8 pages, 7 figures, accepted for publication in Ap
Study of noise reduction characteristics of double-wall panels
The noise reduction characteristics of general aviation type, flat, double-wall structures were investigated. The experimental study was carried out on 20-by-20 inch panels with an exposed area of 18 by 18 inches. A frequency range from 20 to 5000 Hz was covered. The experimental results, in general, follow the expected trends. At low frequencies the double-wall structures are no better than the single-wall structures. However, for depths normally used in the general aviation industry, the double-wall panels are very attractive. The graphite-spoxy skin panels have higher noise reduction at very low frequencies ( 100 Hz) than the Kevlar skin panels. But the aluminum panels have higher noise reduction in the high frequency region, due to their greater mass. Use of fiberglass insulation is not effective in the low frequency region, and at times it is even negative. But the insulation is effective in the high-frequency region. The theoretical model for predicting the transmission loss of these multilayered panels is also discussed
Challenging the orthodoxy: union learning representatives as organic intellectuals
Teacher education and continuing professional development have become a key areas of controversy in England since the period of school sector restructuring following the 1988 Education Reform Act. More recently teacher training and professional development have often been used to promote and reinforce a narrow focus on the governmentâs âstandards agendaâ. However, the emerging discourse of ânew professionalismâ has raised the profile of professional development in schools, and together with union learning representatives, there are opportunities to secure real improvements in teachersâ access to continuing professional development. This paper argues however that union learning representatives must go beyond advocating for better access to professional development and should raise more fundamental questions about the nature of professional development and the education system it serves. Drawing on Gramsciâs notion of the âorganic intellectualâ, the paper argues that union learning representatives have a key role as organisers of ideas â creating spaces in which the ideological dominance of current policy orthodoxy might be challenged
Comparison of competency priorities between UK occupational physicians and occupational health nurses
Objectives: The competencies required of occupational physicians (OPs) and occupational health nurses (OHNs) separately have been studied in various countries but little research has made direct comparisons between these two key occupational health (OH) professional groups. The aim of this study was to compare current competency priorities between UK OPs and OHNs.
Methods: A modified Delphi study conducted among professional organisations and networks of UK OPs and OHNs. This formed part of a larger Delphi, including international OPs. It was undertaken in two rounds (round 1ââratingâ, round 2âârankingâ), using a questionnaire based on available OH competency guidance, the literature, expert panel reviews and conference discussions.
Results: In each round (rating/ranking), 57/49 and 48/54 responses were received for OPs and OHNs respectively. The principle domain (PD) competency ranks were very highly correlated (Spearmanâs r=0.972) with the same PDs featuring in the top four and bottom three positions. OPs and OHNs ranked identically for the top two PDs (good clinical care and general principles of assessment and management of occupational hazards to health). Research methods was ranked lowest by both groups.
Conclusions: This study has observed a high level of agreement among UK OPs and OHNs on current competency priorities. The âclinically focusedâ competency priorities likely reflect that although OH practice will broaden in response to various factors, traditional âcoreâ OH activities will still be required. These mutually identified priorities can serve to strengthen collaboration between these groups, develop joint education/training programmes and identify common professional development opportunities
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