90 research outputs found

    Identification of Substation Configurations in Modern Power Systems using Artificial Intelligence

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    Power system transmission network topology is utilized in energy management system applications. Substation configurations are fundamental to transmission network topology processing. Modern power systems consisting of renewable energy sources require reliable and fast network topology processing due to the variable nature of wind and solar power plants. Currently used transmission network topology processing, which is based on the relay signals communicated through SCADA is not highly reliable or highly accurate. Substation configuration identification (SCI) for different substation arrangements including main and transfer bus arrangement (MTBA), ring bus arrangement (RBA), and single bus arrangement (SBA) is investigated. Synchrophasor measurement based SCI for functional arrangements (FA) using artificial intelligence (AI) approaches is proposed in this paper. This method improves monitoring FA. Typical results for MTBA, RBA and SBA substation configuration identification is presented. A modified two-area four-machine power system model with two grid connected solar PV plants consisting of MTBA, RBA and SBA is simulated on real-time digital simulator. AI based SCI is shown to accurately identify all possible FAs for the three substation arrangements under any operating condition.Comment: In proceedings of the 11th Bulk Power Systems Dynamics and Control Symposium (IREP 2022), July 25-30, 2022, Banff, Canad

    An analytical study of corporate social responsibility and financial performance in banking sector of Sri Lanka

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    Corporate Social Responsibility (CSR) reporting has become an increasing trend in the corporate world. It is a relatively new concept but has become a major research topic in the accounting profession. In recent years, few notions have so fully captured the corporate imagination as that of corporate social responsibility (CSR), defined broadly as a company’s status and activities with respect to its perceived societal or, at least, stakeholder obligations. While CSR is by no means a new idea, more companies than ever before are backing CSR initiatives such as corporate philanthropy, cause-related marketing, minority support programs, and socially responsible employment and manufacturing practicesand they are doing so with real financial and marketing muscle.The motivations behind why companies make voluntary CSR disclosures are unclear. This paper aims to analytically explore the relationship between Corporate Social Responsibility and financial performance among the ten selected banks in Sri Lankan. CSR is measured by using of “Nila Unit” andfinancial performance is measured using two financial ratios namely; Return on Equity and Return on Assets. For the measurement of “Nila Unit” it was used 77 Key words with relates to corporate social Responsibility. This is carried out to see to what extent CSR activities are affected on each banks financial performance over seven years of time.The results indicates that there is a significant positive relationship between Corporate Social Responsibility and Financial Performance

    Maternal and fetal risk factors for stillbirth : population based study

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    Objective: To assess the main risk factors associated with stillbirth in a multiethnic English maternity population. Design: Cohort study. Setting: National Health Service region in England. Population: 92 218 normally formed singletons including 389 stillbirths from 24 weeks of gestation, delivered during 2009-11. Main outcome measure: Risk of stillbirth. Results: Multivariable analysis identified a significant risk of stillbirth for parity (para 0 and para ≥3), ethnicity (African, African-Caribbean, Indian, and Pakistani), maternal obesity (body mass index ≥30), smoking, pre-existing diabetes, and history of mental health problems, antepartum haemorrhage, and fetal growth restriction (birth weight below 10th customised birthweight centile). As potentially modifiable risk factors, maternal obesity, smoking in pregnancy, and fetal growth restriction together accounted for 56.1% of the stillbirths. Presence of fetal growth restriction constituted the highest risk, and this applied to pregnancies where mothers did not smoke (adjusted relative risk 7.8, 95% confidence interval 6.6 to 10.9), did smoke (5.7, 3.6 to 10.9), and were exposed to passive smoke only (10.0, 6.6 to 15.8). Fetal growth restriction also had the largest population attributable risk for stillbirth and was fivefold greater if it was not detected antenatally than when it was (32.0% v 6.2%). In total, 195 of the 389 stillbirths in this cohort had fetal growth restriction, but in 160 (82%) it had not been detected antenatally. Antenatal recognition of fetal growth restriction resulted in delivery 10 days earlier than when it was not detected: median 270 (interquartile range 261-279) days v 280 (interquartile range 273-287) days. The overall stillbirth rate (per 1000 births) was 4.2, but only 2.4 in pregnancies without fetal growth restriction, increasing to 9.7 with antenatally detected fetal growth restriction and 19.8 when it was not detected. Conclusion: Most normally formed singleton stillbirths are potentially avoidable. The single largest risk factor is unrecognised fetal growth restriction, and preventive strategies need to focus on improving antenatal detection

    Sequence balance minimisation: minimising with unequal treatment allocations

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    Background Minimisation ensures excellent balance between groups for several prognostic factors, even in small samples. However, its use with unequal allocation ratios has been problematic. This paper describes a new minimisation scheme named sequence balance minimisation for unequal treatment allocations. Methods Treatment- and factor-balancing properties were assessed in simulation studies for two- and three-arm trials with 1:2 and 1:2:3 allocation ratios. Sample sizes were set 30, 60 and 120. The number of prognostic factors on which to achieve balance was ranged from zero (treatment totals only) to ten with two levels occurring in equal probabilities. Random elements were set at 0.95, 0.9, 0.85, 0.80, 0.7, 0.6 and 0.5. Characteristics of the randomisation distributions and the impact of changing the block size while maintaining the allocation ratio were also examined. Results Sequence balance minimisation has good treatment- and factor-balancing capabilities, and the randomisation distribution was centred at zero for all scenarios. The mean and median number of allocations achieved were the same as the number expected in most scenarios, and including additional factors (up to ten) in the minimisation scheme had little impact on treatment balance. Treatment balance tended to depart from the target as the random element was lowered. The variability in allocations achieved increased slightly as the number of factors increased, as the random element was decreased and as the sample size increased. The mean and median factor imbalance remained tightly around zero even when the chosen factor was not included in the minimisation scheme, though the variability was greater. The variability in factor imbalance increased slightly as the random element decreased, as well as when the number of prognostic factors and sample size increased. Increasing block size while maintaining the allocation ratio improved treatment balance notably with little impact on factor imbalance. Conclusions Sequence balance minimisation has good treatment- and factor-balancing properties and is particularly useful for small trials seeking to achieve balance across several prognostic factors

    Protocol for a mixed methods process evaluation of the Smoking Treatment Optimisation in Pharmacies (STOP) trial

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    This article is a preprint from medRxiv and has not been peer-reviewe

    Steady free-surface flow at the stern of a ship

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    New solutions for steady two-dimensional free-surface flow past a curved plate are considered here. They can be interpreted as approximations to the flow locally at the stern of a ship. Weakly nonlinear solutions are derived analytically and nonlinear solutions are computed by boundary integral equation methods. Analysis in the phase plane provides a way to determine the geometries of hulls that give rise to wave-free stern flows. These waveless flows are desirable as they reduce ship-drag

    Community pharmacy interventions for health promotion: effects on professional practice and health outcomes (Protocol)

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    This is the protocol for a review and there is no abstract. The objectives are as follows: Primary objective To assess the effectiveness of health promotion interventions in community pharmacy practice settings on pharmacy workers and pharmacy clients (including diagnosed patients) when compared to i) No treatment controls ii) Usual treatment controls iii) Other active intervention Secondary objectives To assess whether there are differences in effectiveness of health promotion interventions in community pharmacy practice settings on i) Pharmacy worker ii) Client (patient) with regard to: i) Ethnicity of patients ii) Country income level (World Bank Group 2009) iii) Extent of adverse health behaviour (defined according to national guidelines where available) iv) Type of pharmacy worker delivering the intervention (e.g. pharmacist versus pharmacist technician) v) Theoretical constructs/components and behaviour change techniques employed in the intervention vi) Costs of health car

    Smoking treatment optimisation in pharmacies (STOP): a cluster randomised pilot trial of a training intervention.

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    BACKGROUND: UK government policy aims to strengthen the role of community pharmacies in health promotion. Thus, we conducted feasibility studies for an intervention to enhance delivery of the NHS Smoking Cessation Service. METHODS: The overall aims were to assess acceptability and feasibility of conducting the intervention in community pharmacies and piloting this with a cluster randomised trial. Specific objectives were (1) to estimate likely participation rates of pharmacies and stop smoking advisors, (2) to establish the potential impact of the training intervention on throughput and retention of smokers in smoking services, (3) to establish potential impact on smoking cessation outcomes, (4) to optimise logistics for conducting a cluster randomised trial in the next phase of the research programme and (5) to consider the feasibility of collecting pharmacy and service user data. In this cluster randomised parallel group pilot trial, 12 community pharmacies in East London were allocated to intervention or usual practice using simple randomisation (allocation ratio 2:1). Data were analysed descriptively. RESULTS: Twelve of 54 (22.2%, 95% CI 12.0% to 35.6%) pharmacies and 20 of 23 (87.0%, 95% CI 66.4% to 97.2%) advisors invited, agreed to participate. Over 5 months, 302 smokers in intervention pharmacies (mean per pharmacy 43.1, 95% CI: -4.3 to 90.5) and 319 in usual practice pharmacies (mean per pharmacy 79.8, 95% CI: 19.0 to 140.5) joined the service. 51 of 621 smokers (6.3% in intervention vs 10.0% in usual practice) consented to provide additional data on smoking cessation. 17 of 19 smokers that consented were retained at 4 weeks in intervention arm (89.5%, 95% CI: 66.9% to 98.7%) and 24 of 32 in usual practice (75.0%, 95% CI: 56.6% to 88.5%). 10 of 19 in the intervention arm (52.6%, 95% CI: 28.9% to 75.6%) stopped smoking compared to 7 of 32 in usual practice arm (21.9%, 95% CI: 9.3% to 40.0%). The pilot was useful in providing insights on how best to conduct the definitive trial and shortcomings of our present logistical arrangements, including feasibility of collecting pharmacy and service user data. CONCLUSIONS: Recruitment rates show that the main trial is feasible, and the results suggest that the intervention may improve retention and quit rates in smoking cessation services. We gained insights on how best to conduct the definitive trial which will proceed as planned
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