1,020 research outputs found
How much is too much? Lowering the legal drink-drive limit
The current legal limit on drivers’ blood alcohol content was set at 80mg/100ml nearly 40 years ago and
there are now only 3 other Member States of the European Union, all of them small countries, with limits
higher than 50mg/100ml. Deaths from drink driving in Great Britain stopped falling 10 years ago, and
show signs of rising. The reasons for the setting of the current limit in 1967 and changes since then are
discussed, and a fresh look is taken at the likely annual reduction in deaths on the road in Great Britain if
the limit here were lowered to 50mg/100ml. Lowering the limit is seen not as a measure to be taken in
isolation, but as part of a substantial initiative to resume and sustain a clear downward trend in death and
injury resulting from the avoidable excess risk of driving after drinking
Advancing safe system: The need for realistic goals
Safe System is an approach to road safety management that can be advocated as being the current state of the art; it draws comprehensively upon experience of recent decades in road safety management in many countries. Inspired by Vision Zero, the Safe System Sourcebook purports to eliminate death and life-changing injury from use of the roads. This paper questions whether the elimination of death and life changing injuries is at odds with reality. It calls for an adapted vision with realistically ambitious goals: one of zero preventable deaths and life-changing injuries.
Realistic goals are important for road safety in the realm of day-to-day political reality. Emphasis on realistic goals rather than remote prospects should not only help to advance Safe System but also help to align progress towards it with the promotion of active travel and the creation of places for living and walking in our cities
Video vehicle detection at signalised junctions: a simulation-based study
Many existing advanced methods of traffic signal control depend on information about
approaching traffic provided by inductive loop detectors at particular points in the road. But
analysis of images from CCTV cameras can in principle provide more comprehensive
information about traffic approaching and passing through junctions, and cameras may be
easier to install and maintain than loop detectors, and some systems based on video detection
have already been in use for some time.
Against this background, computer simulation has been used to explore the potential of
existing and immediately foreseeable capability in automatic on-line image analysis to extract
information relevant to signal control from images provided by cameras mounted in
acceptable positions at signal-controlled junctions. Some consequences of extracting relevant
information in different ways were investigated in the context of an existing detailed
simulation model of vehicular traffic moving through junctions under traffic-responsive signal
control, and the development of one basic and one advanced algorithm for traffic-responsive
control. The work was confined as a first step to operation of one very simple signalcontrolled
junction.
Two techniques for extraction of information from images were modelled - a more ambitious
technique based on distinguishing most of the individual vehicles visible to the camera, and a
more modest technique requiring only that the presence of vehicles in any part of the image
be distinguished from the background scene. In the latter case, statistical modelling was used
to estimate the number of vehicles corresponding to any single area of the image that
represents vehicles rather than background.
At the simple modelled junction, each technique of extraction enabled each of the algorithms
for traffic-responsive control of the signals to achieve average delays per vehicle appreciably
lower than those given by System D control, and possibly competitive with those that MOVA
would give, but comparison with MOVA was beyond the scope of the initial study.
These results of simulation indicate that image analysis of CCTV pictures should be able to
provide sufficient information in practice for traffic-responsive control that is competitive
with existing techniques. Ways in which the work could be taken further were discussed with
practitioners, but have not yet been progressed
A validated BEM model to analyse hydrodynamic loading on tidal stream turbines blades
This is the author accepted manuscript. The final version is available from the link in this record.AWTEC 2016: 3rd Asian Wave and Tidal Energy Conference, 24-28 October 2016, SingaporeThis paper details a Blade Element Momentum (BEM) model for a 3 bladed, horizontal axis Tidal Stream Turbine (TST). The code capabilities are tested and validated by applying a range of different turbine parameters and operating conditions, where results are compared to numerous datasets. The model shows excellent agreement to performance and thrust measurements for 3 of the 4 datasets. Compared to other BEM models improved correlations are seen at higher rotational speeds. The fourth case shows over predictions of up to 30% in power at peak operating speed. In this case, CFD studies show better correlation due to the ability to capture detailed flow features around the blade as well as free surface effects, however require 3 to 4 orders of magnitude greater computational cost. Steady, non-uniform inflow functionality is incorporated into the model, where distributions of thrust and torque along the blade as well as cyclic loads are determined. These show the potential of the model to be used in combination with tools such as stress and fatigue analyses to improve the blade design process.This research is carried out as part of the Industrial Doctoral Centre for Offshore Renewable Energy (IDCORE) programme, funded by the Energy Technology partnership and the RCUK Energy programme (Grant number EP/J500847/1), in collaboration with EDF R&D
Physical characteristics of localized surface plasmons resulting from nano-scale structured multi-layer thin films deposited on D-shaped optical fiber
Novel surface plasmonic optical fiber sensors have been fabricated using multiple coatings deposited on a lapped section of a single mode fiber. UV laser irradiation processing with a phase mask produces a nano-scaled surface relief grating structure resembling nano-wires. The resulting individual corrugations produced by material compaction are approximately 20 μm long with an average width at half maximum of 100 nm and generate localized surface plasmons. Experimental data are presented that show changes in the spectral characteristics after UV processing, coupled with an overall increase in the sensitivity of the devices to surrounding refractive index. Evidence is presented that there is an optimum UV dosage (48 joules) over which no significant additional optical change is observed. The devices are characterized with regards to change in refractive index, where significantly high spectral sensitivities in the aqueous index regime are found, ranging up to 4000 nm/RIU for wavelength and 800 dB/RIU for intensity
A high sensitivity refractometer based upon a long period grating Mach-Zehnder interferometer
A low cost interrogation scheme is demonstrated for a refractometer based on an in-line fiber long period grating (LPG) Mach–Zehnder interferometer. Using this interrogation scheme the minimum detectable change in refractive index of ?n ~ 1.8×10-6 is obtained, which is the highest resolution achieved using a fiber LPG device, and is comparable to precision techniques used in the industry including high performance liquid chromatography and ultraviolet spectroscopy
Potential and challenges in collecting social and behavioral data on adolescent alcohol norms: Comparing respondent-driven sampling and web-based respondent-driven sampling
Background: Respondent-driven sampling (RDS) is a method successfully used to research hard-to-access populations. Few studies have explored the use of the Internet and social media with RDS, known as Web-based RDS (WebRDS). This study explored the use of combining both "traditional" RDS and WebRDS to examine the influences on adolescent alcohol use. Objective: This paper reports on the recruitment processes and the challenges and enablers of both RDS and WebRDS. It details comparative recruitment data and provides a summary of the utility of both methods for recruiting adolescents to participate in an online survey investigating youth alcohol norms. Methods: Process evaluation data collected from research staff throughout the study were used to assess the challenges and solutions of RDS and WebRDS. Pearson chi-square test (Fisher's exact test if applicable) was used to compare the differences in sociodemographics and drinking behavior between data collected by RDS and WebRDS. Results: Of the total sample (N=1012), 232 adolescents were recruited by RDS and 780 by WebRDS. A significantly larger proportion of Aboriginal or Torres Strait Islander (P<.001) participants who spoke English as their main language at home (P=.03), and of middle and lower socioeconomic status (P<.001) was found in the RDS sample. The RDS sample was also found to have a higher occurrence of past 7-day drinking (P<.001) and past 7-day risky drinking (P=.004). No significant differences in gender, age, past month alcohol use, and lifetime alcohol use were observed between the RDS and WebRDS samples. This study revealed RDS and WebRDS used similar lengths of chains for recruiting participants; however, WebRDS conducted a faster rate of recruitment at a lower average cost per participant compared to RDS. Conclusions: Using WebRDS resulted in significant improvements in the recruitment rate and was a more effective and efficient use of resources than the traditional RDS method. However, WebRDS resulted in partially different sample characteristics to traditional RDS. This potential effect should be considered when selecting the most appropriate data collection method
Mobile devices in palliative care services: a methodological approach to identifying use and implementation
The use of mobile devices is developing in palliative care services, promising enhancements to patient care and service delivery. However, mobile device use is not well documented in the research literature even though it is necessary to understand how its use is developing in the medical field. Therefore, an online survey was developed in English, French and Arabic and distributed across palliative care providers in the 33 out of 54 countries in Africa where palliative care services are present. The survey gathered information about the service provided where a respondent was based, and a framework was presented to respondents documenting the different stages of palliative care delivery (ie, diagnosis, referral, up to bereavement care). For each stage of delivery, participants were asked to outline how they currently use mobile devices and to specify any perceived barriers and benefits to mobile device development at their site, alongside thoughts on priorities for future research development. The results of this survey, and the priorities it indicates, will be presented
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