285 research outputs found
Investigation of a Compound Helicopter Flying the Depart and Abort Mission Task Element
The next generation of rotorcraft will have to satisfy the appropriate handling qualities requirements before
entering service. Many of these vehicles will operate at significantly greater speeds than the conventional
helicopter and will therefore have different capabilities than current helicopters. Due to the different capabilities
of the compound helicopter, it is possible that new Mission Task Elements (MTEs) need to be
developed to assess the handling qualities of this type of helicopter. It is also possible that existing MTEs
may be suitable without modification. Overall, it seems necessary to review the US Army’s current handling
qualities specification, ADS-33, and determine the suitability of the current MTEs for compound vehicles.
The broad aim of the paper is to assess the performance of compound helicopter during manoeuvring flight.
More specifically, a simulation study of a compound helicopter flying the Depart and Abort ADS-33 Mission
Task Element. There are two objectives: firstly the capabilities of the compound vehicle is compared
with those of a conventional helicopter, and secondly, the suitability of the current Depart and Abort MTE,
for compound vehicles, is assessed. The results of the research study highlight the capability of compound
helicopters in low speed acceleration manoeuvres. These results can be used to redefine low speed acceleration
manoeuvres in the new update to the ADS-33 specification. The results also indicate some information
about the potential design issues with the compound helicopter
Pulsars above 10 GeV: Fermi LAT Observations and Questions
The success of the Fermi Large Area Telescope in studying gamma-ray pulsars offers hints about future work above 10 GeV. The infrastructure for discovering pulsars will be similar between LAT and any future telescope. Some of the Fermi LAT results suggest intriguing questions about the future of high-energy pulsar studies
A review and evaluation of secondary school accountability in England:Statistical strengths, weaknesses, and challenges for 'Progress 8'
School performance measures are published annually in England to hold schools
to account and to support parental school choice. This article reviews and
evaluates the Progress 8 secondary school accountability system for
state-funded schools. We assess the statistical strengths and weaknesses of
Progress 8 relating to: choice of pupil outcome attainment measures; potential
adjustments for pupil input attainment and background characteristics;
decisions around which schools and pupils are excluded from the measure;
presentation of Progress 8 to users, choice of statistical model, and
calculation of statistical uncertainty; and issues related to the volatility of
school performance over time, including scope for reporting multi-year
averages. We then discuss challenges for Progress 8 raised by the COVID-19
pandemic. Six simple recommendations follow to improve Progress 8 and school
accountability in England.Comment: 67 pages, 8 figure
Creating transient gradients in supramolecular hydrogels
The self‐assembly of low molecular weight gelators in water usually produces homogeneous hydrogels. However, homogeneous gels are not always desired. Using a photoacid generator, it is shown how to form gels with a transient gradient in stiffness, proved using cavitation and bulk rheology. Small‐angle neutron scattering is used to show that the gels formed by photoacid are the result of the same structures as when using a conventional pH trigger. Patterned gels can also be formed, again with transient differences in stiffness
A review and evaluation of secondary school accountability in England: Statistical strengths, weaknesses, and challenges for 'Progress 8' raised by Covid-19
School performance measures are published annually in England to hold schools to account and to support parental school choice. This article reviews and evaluates the ‘Progress 8’ secondary school accountability system for state-funded schools. We assess the statistical strengths and weaknesses of Progress 8 relating to: choice of pupil outcome attainment measure; potential adjustments for pupil input attainment and background characteristics; decisions around which schools and pupils are excluded from the measure; presentation of Progress 8 to users, choice of statistical model, and calculation of statistical uncertainty; and issues related to the volatility of school performance over time, including scope for reporting multi-year averages. We then discuss challenges for Progress 8 raised by the COVID-19 pandemic. Six simple recommendations follow to improve Progress 8 and school accountability in England. Context and implication Rationale for this study This study fulfils a need for a comprehensive statistical evaluation of the Progress 8 school accountability system in England, which has been in place since 2016. Why the new findings matter A review of Progress 8 is an important contribution as decisions on its calculation and presentation have important consequences for schools and pupils. Implications for educational researchers and policy makers Our findings on the statistical strengths and weaknesses of Progress 8 and the resulting recommendations made for improvements to the measure and school accountability have clear implications for informing policy makers in the educational system. This includes wider lessons extending beyond Progress 8 to other performance metrics and to other school systems internationally where similar issues apply. Additionally, the review highlights key concerns that the public and school practitioners may like to consider when drawing upon Progress 8 to make decisions around school choice and in assessing how well a school is performing
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