63,007 research outputs found
The role of pecuniary and non-pecuniary factors in teacher turnover and mobility decisions
We investigate the determinants of teacher exits from and mobility within the Queensland state school system. In common with previous research we find that non-pecuniary factors, such as class size and location, affect movement decisions but our results suggest a significant role for pecuniary factors. In particular, higher wages reduce exits from the public sector, especially in the case of more experienced female teachers. Locality allowances paid to teachers in rural and remote schools, where non-pecuniary factors are less attractive, appear to have some success in attracting and retaining staff in these locations
Non-linear quantum critical transport and the Schwinger Mechanism
Scaling arguments imply that quantum critical points exhibit universal
non-linear responses to external probes. We investigate the origins of such
non-linearities in transport, which is especially problematic since the system
is necessarily driven far from equilibrium. We argue that for a wide class of
systems the new ingredient that enters is the Schwinger mechanism--the
production of carriers from the vacuum by the applied field-- which is then
balanced against a scattering rate which is itself set by the field. We show by
explicit computation how this works for the case of the symmetric
superfluid-Mott insulator transition of bosons
Worker absence and shirking: evidence from matched teacher-school data
We utilise a unique matched teacher-school data set of absenteeism records to quantify shirking behaviour in primary and secondary schools. Shirking behaviour is shown to vary systematically across schools, and hence schools are characterised as either healthy (low absenteeism) or sick (high absenteeism). Using count data techniques, and allowing for the problems of unobserved heterogeneity and partial observability in our data, we find that teachers in sick schools have higher absence rates. Our estimates suggest that shirking behaviour can account for 24 percent to 38 percent of recorded absenteeism. Furthermore, a teacher who moves from a healthy school to a sick school is likely to face an increased risk of absenteeism of up to 70 percent. As the factors a¤ecting involuntary absenteeism are unlikely to change in the short run, we argue that this increased incidence in absenteeism re?ects the impact of the change in school environment on shirking behaviour.
Dispersion of microbes from floors when walking in ventilated rooms
The redispersion factor of microbe-carrying particles, which is the ratio of the concentration of floor-derived microbes in room air to those on a floor surface, was determined, as was the percentage of floor-derived microbes in room air. These relationships were shown to vary according to conditions in the room. Equations were derived that allow these relationships to be calculated for a variety of room conditions, including air supply rates, levels of personnel activity, and the effect of gravitational deposition on microbe-carrying particles.<p></p>
The redispersion factor in ventilated rooms, such as cleanrooms and operating rooms, when the floor surface concentration was measured by nutrient agar contact dishes, was found to vary from about 1.5 x 10-4 to 7.4 x 10-6, and the percentage of floor-derived microbes in room air from about 0.004% to 10.5%. In a typical cleanroom, the redispersion factor is likely to be about 1.0 x 10-4, and the percentage of floor-derived microbes, 0.7. In a typical operating room, the redispersion factor is likely to be about 5.2 x 10-6 and the percentage of floor-derived microbes, 2.<p></p>
Assessment and learning outcomes: the evaluation of deep learning in an on-line course
Using an online learning environment, students from European countries collaborated and communicated to carry out problem based learning in occupational therapy. The effectiveness of this approach was evaluated by means of the final assessments and published learning outcomes. In particular, transcripts from peer-to-peer sessions of synchronous communication were analysed. The SOLO taxonomy was used and the development of deep learning was studied week by week. This allowed the quality of the course to be appraised and showed, to a certain extent, the impact of this online international course on the learning strategies of the students. Results indicate that deep learning can be supported by synchronous communication and online meetings between course participants.</p
Experimental and numerical investigation on micro deep drawing process of stainless steel 304 foil using flexible tools
Flexible forming technology provides significant application potential in various areas of manufacturing, particularly at a miniaturized level. Simplicity, versatility of process and feasibility of prototyping makes forming techniques by using flexible tools suitable for micro sheet metal forming. This paper reports the results of FE simulation and experimental research on micro deep drawing processes of stainless steel 304 sheets utilising a flexible die. The study presents a novel technique in which an initial gap (positive or negative) is adopted between an adjustment ring and a blank holder employed in the developed forming system. The blank holder is moveable part and supported by a particular spring that provides the required holding force. The forming parameters (anisotropy of SS 304 material, initial gap, friction conditions at various contact interfaces and initial sheet thickness) related with the forming process are in details investigated. The FE models are built using the commercial code Abaqus/Standard. The numerical predictions reveal the capability of the proposed technique on producing micro metallic cups with high quality and large aspect ratio. To verify these results, number of micro deep drawing experiments is conducted using a special set up developed for this purpose. As providing a fundamental understanding is required for the commercial development of this novel forming technique, hence the optimization of the initial gap in accordance with each sheet thickness, thickness distribution and punch force/stroke relationship are detected
The role of pecuniary and non-pecuniary factors in teacher turnover and mobility decisions
We investigate the determinants of teacher exits from and mobility within the Queensland state school system. In common with previous research we find that non-pecuniary factors, such as class size and location, affect movement decisions but our results suggest a significant role for pecuniary factors. In particular, higher wages reduce exits from the public sector, especially in the case of more experienced female teachers. Locality allowances paid to teachers in rural and remote schools, where non-pecuniary factors are less attractive, appear to have some success in attracting and retaining staff in these locations.
Newtonian limit of String-Dilaton Gravity
We study the weak-field limit of string-dilaton gravity and derive
corrections to the Newtonian potential which strength directly depends on the
self interaction potential and the nonminimal coupling of the dilaton scalar
field. We discuss also possible astrophysical applications of the results, in
particular the flat rotation curves of spiral galaxies.Comment: 11 pages, LATEX file, to appear in IJMP
A methodology for full-system power modeling in heterogeneous data centers
The need for energy-awareness in current data centers has encouraged the use of power modeling to estimate their power consumption. However, existing models present noticeable limitations, which make them application-dependent, platform-dependent, inaccurate, or computationally complex. In this paper, we propose a platform-and application-agnostic methodology for full-system power modeling in heterogeneous data centers that overcomes those limitations. It derives a single model per platform, which works with high accuracy for heterogeneous applications with different patterns of resource usage and energy consumption, by systematically selecting a minimum set of resource usage indicators and extracting complex relations among them that capture the impact on energy consumption of all the resources in the system. We demonstrate our methodology by generating power models for heterogeneous platforms with very different power consumption profiles. Our validation experiments with real Cloud applications show that such models provide high accuracy (around 5% of average estimation error).This work is supported by the Spanish Ministry of Economy and Competitiveness under contract TIN2015-65316-P, by the Gener-
alitat de Catalunya under contract 2014-SGR-1051, and by the European Commission under FP7-SMARTCITIES-2013 contract 608679 (RenewIT) and FP7-ICT-2013-10 contracts 610874 (AS- CETiC) and 610456 (EuroServer).Peer ReviewedPostprint (author's final draft
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