1,247 research outputs found
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
Determining the extent to which simulation can be used to train RAF pilots to fly and fight the Eurofighter Typhoon
This research examines the extent to which simulation can be used to train pilots of the Royal Air Force to fly and fight the Eurofighter Typhoon, and is the culmination of a series of trials over a period of 4 years. The approach was threefold, firstly examining the performance of students trained entirely on the Operational Conversion Unit’s full syllabus in the simulator and then tested against their peers on each of the four phases in live flight, secondly investigating the cultural acceptance levels of the present Typhoon pilots and lastly using lessons learnt to generate and test a syllabus to train Typhoon pilots to Mult Role Combat Ready in 40% of the present time. It was found that increasing the proportion of synthetics from the lowest Live Synthetic Balance (LSB) of 75:25 used on the front-line meets a cultural and resource barrier at 50:50. This did not represent the maximum LSB achievable however with the heavily synthetic Multi-Role Syllabus reaching an LSB of 21:79 with successful completion of the end of course test.
Cultural acceptance of the simulator had correlations with the squadron a pilot was assigned to, the manner in which the simulators were programmed for use and the experience level of the pilot. No evidence was found within the sample to suggest age had an effect. Recommendations on minimum proportions of live and synthetic training was mapped for each of the required tasks and comparisons of these were made across complexity levels.
Resource savings found by the generating and testing a Multi Role Combat Ready syllabus that recognised and incorporated all the strengths, weaknesses and lessons identified in the previous trials generated a saving of approximately 9 months and 100 Typhoon live flying hours per student, equivalent to approximately 1300 man maintenance hours that could be reinvested into personnel in the form of leave, adventurous training or development
Orphan Breakwaters - what protection is given when they collapse?
Around the UK, many coastal harbours have reduced in importance and/or lost the original sources of income against which to defray maintenance or refurbishment. Their breakwaters may however still protect harbour-side properties against wave overtopping, and thus flooding. This paper presents results from an exploratory study to identify how blockwork breakwaters common in many smaller UK coastal harbours may collapse due to storm action, and in this paper, how much wave protection is given by collapsed breakwaters. The companion paper by Pearson & Allsop (2017) describes initial work to estimate the failure of blockwork walls, and presents results of wall collapse tests
What determines duration of palliative care before death for patients with advanced disease? A retrospective cohort study of community and hospital palliative care provision in a large UK city
Objective For patients with advanced cancer, several randomised controlled trials have shown that access to palliative care at least 6 months before death can improve symptoms, reduce unplanned hospital admissions, minimize aggressive cancer treatments and enable patients to make choices about their end of life care, including exercising the choice to die at home. This study determines in a UK population the duration of palliative care before death and explores influencing factors. Design This retrospective cohort study analysed referrals to three specialist palliative care services; a hospital based inpatient palliative care team, and two community based services (hospices). For each patient referred to any of the above services we identified the date of first referral to that team and calculated the median interval between first referral and death. We also calculated how referral time varied by age, sex, diagnosis and type of palliative care service. Participants 4,650 patients referred to specialist palliative care services in Leeds UK between April 2012 and March 2014. Results Median age of the sample was 75 years. 3,903 (84.0%) patients had a diagnosis of cancer. Age, diagnosis and place of referral were significant predictors of duration of palliative care before death. Age was independently associated (J = 2672078, z = -392046.14, r = .01) with duration of palliative care regardless of diagnosis. Patients over 75 years have 29 fewer days of palliative care than patients under 50. Patients with non-cancer diagnoses have 13 fewer days of palliative care than patients with cancer. Additionally, patients referred to hospital palliative care receive 24.5 fewer days palliative care than those referred to community palliative care services. Conclusions The current timing of referral to palliative care may limit the benefits to patient in terms of improvements in end of life care, particularly for older patients and patients with conditions other than cancer
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
Research activities arising from the University of Kent
In this paper I describe research activities in the field of optical fiber sensing undertaken by me after leaving the Applied Optics Group at the University of Kent. The main topics covered are long period gratings, neural network based signal processing, plasmonic sensors, and polymer fiber gratings. I also give a summary of my two periods of research at the University of Kent, covering 1985–1988 and 1991–2001
How do Money, Sex, and Stress Influence Marital Instability?
This study explored how money and sex simultaneously predicted marital instability, and what financial therapists might focus on with clients to address problems in these areas. Specifically, this paper concurrently examined the relationship of marital instability to financial and family stressors (financial stressors, work-family conflict, and parenting stressors); financial and sexual resources (couple income and couple sexual frequency); and financial and sexual perceptions (financial dissatisfaction and sexual dissatisfaction). Couple financial communication and couple relational communication were explored as intervention points for financial therapists. Data came from Wave 2 of the Flourishing Families data set (N = 301). Data were organized using the ABC-X model of family stress (Hill, 1949) and integrated with Gottman\u27s research on the importance of relational communication (Navarra, Gottman, & Gottman, 2016). Path analysis revealed that family financial stressors were associated with greater financial dissatisfaction and sexual dissatisfaction. Work-family conflict was associated with greater couple income, and parenting stressors were positively associated with sexual dissatisfaction. Couple income was associated with lower financial dissatisfaction, and sexual frequency was associated with lower sexual dissatisfaction. Both financial dissatisfaction and sexual dissatisfaction predicted greater marital instability; however, healthy couple financial communication and healthy couple relationship communication fully mediated these two associations. This suggests that if financial therapists help clients to communicate more productively about money and sex, problems such as financial stress, work-family conflict, inadequate income, and conflicts about sexual frequency may be less likely to lead to divorce
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