Network Usage Determination for Transmission Cost Allocation using a Transformer Analogy

This study presents a new method for determining the transmission network usage by loads and generators, which can then be used for transmission cost/loss allocation in an explainable and justifiable manner. The proposed method is based on solid physical grounds and circuit theory. It relies on dividing the currents through the network into two components; the first one is attributed to power flows from generators to loads, whereas the second one is because of the generators only. Unlike almost all the available methods, the proposed method is assumption free and hence it is more accurate than similar methods even those having some physical basis. The proposed method is validated through a transformer analogy, and theoretical derivations. The method is verified through application to the IEEE 30 bus system and the IEEE 118 test system. The results obtained verified many desirable features of the proposed method. Being more accurate in determining the network usage, in an explainable transparent manner, and in giving accurate cost signals, indicating the best locations to add loads and generation, are among the many desirable features.

Gabions: evaluation of potential as low-cost roadside barriers

This paper evaluates the potential of gabions as roadside safety barriers. Gabions have the capacity to blend into natural landscape, suggesting that they could be used as a safety barrier for low-volume road in scenic environments. In fact, gabions have already been used for this purpose in Nepal, but the impact response was not evaluated. This paper reports on numerical and experimental investigations performed on a new gabion barrier prototype. To assess the potential use as a roadside barrier, the optimal gabion unit size and mass were investigated using multibody analysis and four sets of 1:4 scaled crash tests were carried out to study the local vehicle-barrier interaction. The barrier prototype was then finalised and subjected to a TB31 crash test according to the European EN1317 standard for N1 safety barriers. The test resulted in a failure due to the rollover of the vehicle and tearing of the gabion mesh yielding a large working width. It was found that although the system potentially has the necessary mass to contain a vehicle, the barrier front face does not have the necessary stiffness and strength to contain the gabion stone filling and hence redirect the vehicle. In the EN1317 test, the gabion barrier acted as a ramp for the impacting vehicle, causing rollover. 

Cost-Directed Refactoring for Parallel Erlang Programs

This paper presents a new programming methodology for introducing and tuning parallelism in Erlang programs, using source-level code refactoring from sequential source programs to parallel programs written using our skeleton library, Skel. High-level cost models allow us to predict with reasonable accuracy the parallel performance of the refactored program, enabling programmers to make informed decisions about which refactorings to apply. Using our approach, we demonstrate easily obtainable, significant and scalable speedups of up to 21 on a 24-core machine over the sequential code.

Estimating the incidence, prevalence and true cost of asthma in the UK: Secondary analysis of national stand-alone and linked databases in England, Northern Ireland, Scotland and Wales-a study protocol

Introduction Asthma is now one of the most common long-term conditions in the UK. It is therefore important to develop a comprehensive appreciation of the healthcare and societal costs in order to inform decisions on care provision and planning. We plan to build on our earlier estimates of national prevalence and costs from asthma by filling the data gaps previously identified in relation to healthcare and broadening the field of enquiry to include societal costs. This work will provide the first UK-wide estimates of the costs of asthma. In the context of asthma for the UK and its member countries (ie, England, Northern Ireland, Scotland and Wales), we seek to: (1) produce a detailed overview of estimates of incidence, prevalence and healthcare utilisation; (2) estimate health and societal costs; (3) identify any remaining information gaps and explore the feasibility of filling these and (4) provide insights into future research that has the potential to inform changes in policy leading to the provision of more cost-effective care.

Methods and analysis Secondary analyses of data from national health surveys, primary care, prescribing, emergency care, hospital, mortality and administrative data sources will be undertaken to estimate prevalence, healthcare utilisation and outcomes from asthma. Data linkages and economic modelling will be undertaken in an attempt to populate data gaps and estimate costs. Separate prevalence and cost estimates will be calculated for each of the UK-member countries and these will then be aggregated to generate UK-wide estimates.

Ethics and dissemination Approvals have been obtained from the NHS Scotland Information Services Division's Privacy Advisory Committee, the Secure Anonymised Information Linkage Collaboration Review System, the NHS South-East Scotland Research Ethics Service and The University of Edinburgh's Centre for Population Health Sciences Research Ethics Committee. We will produce a report for Asthma-UK, submit papers to peer-reviewed journals and construct an interactive map.

Optical coherence tomography for the diagnosis, monitoring and guiding of treatment for neovascular age-related macular degeneration:a systematic review and economic evaluation

BACKGROUND: Age-related macular degeneration is the most common cause of sight impairment in the UK. In neovascular age-related macular degeneration (nAMD), vision worsens rapidly (over weeks) due to abnormal blood vessels developing that leak fluid and blood at the macula.

OBJECTIVES: To determine the optimal role of optical coherence tomography (OCT) in diagnosing people newly presenting with suspected nAMD and monitoring those previously diagnosed with the disease.

DATA SOURCES: Databases searched: MEDLINE (1946 to March 2013), MEDLINE In-Process & Other Non-Indexed Citations (March 2013), EMBASE (1988 to March 2013), Biosciences Information Service (1995 to March 2013), Science Citation Index (1995 to March 2013), The Cochrane Library (Issue 2 2013), Database of Abstracts of Reviews of Effects (inception to March 2013), Medion (inception to March 2013), Health Technology Assessment database (inception to March 2013).

REVIEW METHODS: Types of studies: direct/indirect studies reporting diagnostic outcomes.

INDEX TEST: time domain optical coherence tomography (TD-OCT) or spectral domain optical coherence tomography (SD-OCT).

COMPARATORS: clinical evaluation, visual acuity, Amsler grid, colour fundus photographs, infrared reflectance, red-free images/blue reflectance, fundus autofluorescence imaging, indocyanine green angiography, preferential hyperacuity perimetry, microperimetry. Reference standard: fundus fluorescein angiography (FFA). Risk of bias was assessed using quality assessment of diagnostic accuracy studies, version 2. Meta-analysis models were fitted using hierarchical summary receiver operating characteristic curves. A Markov model was developed (65-year-old cohort, nAMD prevalence 70%), with nine strategies for diagnosis and/or monitoring, and cost-utility analysis conducted. NHS and Personal Social Services perspective was adopted. Costs (2011/12 prices) and quality-adjusted life-years (QALYs) were discounted (3.5%). Deterministic and probabilistic sensitivity analyses were performed.

RESULTS: In pooled estimates of diagnostic studies (all TD-OCT), sensitivity and specificity [95% confidence interval (CI)] was 88% (46% to 98%) and 78% (64% to 88%) respectively. For monitoring, the pooled sensitivity and specificity (95% CI) was 85% (72% to 93%) and 48% (30% to 67%) respectively. The FFA for diagnosis and nurse-technician-led monitoring strategy had the lowest cost (£39,769; QALYs 10.473) and dominated all others except FFA for diagnosis and ophthalmologist-led monitoring (£44,649; QALYs 10.575; incremental cost-effectiveness ratio £47,768). The least costly strategy had a 46.4% probability of being cost-effective at £30,000 willingness-to-pay threshold.

LIMITATIONS: Very few studies provided sufficient information for inclusion in meta-analyses. Only a few studies reported other tests; for some tests no studies were identified. The modelling was hampered by a lack of data on the diagnostic accuracy of strategies involving several tests.

CONCLUSIONS: Based on a small body of evidence of variable quality, OCT had high sensitivity and moderate specificity for diagnosis, and relatively high sensitivity but low specificity for monitoring. Strategies involving OCT alone for diagnosis and/or monitoring were unlikely to be cost-effective. Further research is required on (i) the performance of SD-OCT compared with FFA, especially for monitoring but also for diagnosis; (ii) the performance of strategies involving combinations/sequences of tests, for diagnosis and monitoring; (iii) the likelihood of active and inactive nAMD becoming inactive or active respectively; and (iv) assessment of treatment-associated utility weights (e.g. decrements), through a preference-based study.

STUDY REGISTRATION: This study is registered as PROSPERO CRD42012001930.

FUNDING: The National Institute for Health Research Health Technology Assessment programme.

A simple and low-cost method for the preparation of self-supported TiO2-WO3 ceramic heterojunction wafers

Robust, bilayer heterojunction photodiodes of TiO₂-WO₃ were prepared successfully by a simple, low-cost powder pressing technique followed by heat-treatment. Exclusive photoirradiation of the TiO₂ side of the photodiode resulted in a rapid colour change (dark blue) on the WO₃ surface as a result of reduction of W⁶⁺ to W⁵⁺ (confirmed by X-ray photoelectron spectroscopy). This colour was long lived and shown to be stable in a dry environment in air for several hours. A similar photoirradiation experiment in the presence of a mask showed that charge transfer across the heterojunction occurred approximately normal to the TiO₂ surface, with little smearing out of the mask image. As a result of the highly efficient vectorial charge separation, the photodiodes showed a tremendous increase in photocatalytic activity for the degradation of stearic acid, compared to wafers of the respective individual materials when tested separately.

Cost-effectiveness of tooth replacement strategies for partially dentate elderly: a randomized controlled clinical trial

OBJECTIVE: To conduct a cost-effectiveness analysis comparing two different tooth replacement strategies for partially dentate older patients, namely partial removable dental prostheses (RDP) and functionally orientated treatment based on the shortened dental arch concept (SDA).

METHODS: Ninety-two partially dentate older patients completed a randomized controlled clinical trial. Patients were randomly allocated to two treatment groups: the RDP group and the SDA group. Treatment effect was measured using impact on oral health-related quality of life (OHrQOL), and the costs involved in providing and maintaining care were recorded for all patients. Patients were followed for 12 months after treatment intervention. All treatment was provided by a single operator.

RESULTS: The total cost of achieving the minimally important clinical difference (MID) in OHrQOL for an average patient in the RDP group was €464.64. For the SDA group, the cost of achieving the MID for an average patient was €252.00. The cost-effectiveness ratio was therefore 1:1.84 in favour of SDA treatment.

CONCLUSION: With an increasingly ageing population, many patients will continue to benefit from removable prostheses to replace their missing natural teeth. From a purely economic standpoint, the results from this analysis suggest that the treatment of partially dentate older adults should be focused on functionally orientated treatment because it is simply more cost-effective.

Cost-effectiveness of ART restorations in elderly adults: a randomized clinical trial

BACKGROUND: As the world population ages, the requirement for cost-effective methods of treating chronic disease conditions increases. In terms of oral health, there is a rapidly increasing number of dentate elderly with a high burden of maintenance. Population surveys indicate that older individuals are keeping their teeth for longer and are a higher caries risk group. Atraumatic Restorative Treatment (ART) could be suitable for patients in nursing homes or house-bound elderly, but very little research has been done on its use in adults.

OBJECTIVES: To compare the cost-effectiveness of ART and a conventional technique (CT) for restoring carious lesions as part of a preventive and restorative programme for older adults.

METHODS: In this randomized clinical trial, 82 patients with carious lesions were randomly allocated to receive either ART or conventional restorations. Treatment costs were measured based on treatment time, materials and labour. For the ART group, the cost of care provided by a dentist was also compared to the cost of having a hygienist to provide treatment. Effectiveness was measured using percentage of restorations that survived after a year.

RESULTS: Eighty-two patients received 260 restorations, that is, 128 ART and 132 conventional restorations. 91.1% of the restorations were on one surface only. After a year, 252 restorations were assessed in 80 patients. The average cost for ART and conventional restorations was €16.86 and €28.71 respectively; the restoration survival percentages were 91.1% and 97.7%, respectively. This resulted in a cost-effectiveness ratio of 0.18 (ART) and 0.29 (CT). When the cost of a hygienist to provide ART was inserted in the analysis, the resulting ratio was 0.14.

CONCLUSIONS: Atraumatic restorative treatment was found to be a more cost-effective alternative to treat older adults after 1 year, compared to conventional restorations, especially in out of surgery facilities and using alternative workforce such as hygienists. Atraumatic restorative treatment can be a useful tool to provide dental care for frail and fearful individuals who might not access dental treatment routinely.

A preliminary report of the cost-effectiveness of tooth replacement strategies for partially dentate elders

OBJECTIVE: To compare the cost-effectiveness of conventional treatment using partial dentures with functionally orientated treatment to replace missing teeth for partially dentate elders using a randomised controlled clinical trial.

BACKGROUND: In many countries, including the Republic of Ireland, the only publically funded treatment option offered to partially dentate older patients is a removable partial denture. However, evidence suggests that these removable prostheses are unpopular with patients and can potentially increase the risk of further dental disease and subsequent tooth loss.

MATERIALS AND METHODS: Fourty-four partially dentate patients aged 65 years and older were recruited. Patients were randomly assigned to the two treatment arms of the study. The conventional treatment group received removable partial dentures to replace all missing natural teeth. The functionally orientated group was restored to a Shortened Dental Arch (SDA) of 10 occluding contacts using resin-bonded bridgework (RBB). The costs associated with each treatment were recorded. Effectiveness was measured in terms of the impact on oral health-related quality of life (OHRQoL) using OHIP-14.

RESULTS: Both groups reported improvements in OHRQoL 1 month after completion of treatment. The conventional treatment group required 8.3 clinic visits as compared to 4.4 visits for the functionally orientated group. The mean total treatment time was 183 min 19 s for the conventional group vs. 124 min 8 s for the functionally orientated group. The average cost of treatment for the conventional group was 487.74 Euros compared to 356.20 Euros for the functional group.

CONCLUSIONS: Functionally orientated treatment was more cost-effective than conventional treatment in terms of treatment effect and opportunity costs to the patients' time.

A cluster randomised controlled trial evaluation and cost-effectiveness analysis of the Roots of Empathy schools-based programme for improving social and emotional wellbeing outcomes among 8-9 year olds in Northern Ireland

A substantial body of evidence suggest that well designed school based prevention programmes can be effective in improving a variety of social, health and academic outcomes for children and young people. This poster presents the methodology for evaluating the Roots of Empathy (ROE) programme. ROE is a universal programme delivered on a whole-class basis for one academic year. It consists of 27 lessons that run over a school year and is based around a monthly classroom visit by an infant and parent, typically recruited from the local community, whom the class 'adopts' at the start of the school year. The evaluation aims to evaluate the immediate and longer term impact of ROE on social and emotional wellbeing outcomes among 8-9 year old pupils, as well as evaluate the cost-effectiveness of the programme.