On the Power Efficiency of Artificial Neural Network (ANN) and the Classical Regression Model

This research work presents new development in the field of natural science, where comparison is made theoretically on the efficiency of both classical regression models and that of artificial neural network models, with various transfer functions without data consideration. The results obtained based on variance estimation indicates that ANN is better which coincides with the results of Authors in the past on the efficiency of ANN over the traditional regression models. The certain conditions required for ANN efficiency over the conventional regression models were noted only that the optimal number of hidden layers and neurons needed to achieve minimum error is still open to further investigation.Key words

On the Exponentiated Weibull Distribution for Modeling Wind Speed in South Western Nigeria

One of the bases for assessment of wind energy potential for a specified region is the probability distribution of wind speed. Thus, appropriate and adequate specification of the probability distribution of wind speed becomes increasingly important. Several distributions have been proposed for describing wind distribution. Among the most popular distributions is the Weibull whose choice is due to its flexibility. An exponentiated Weibull distribution is proposed as an alternative to model wind speed data with a view to comparing it with the existing Weibull distribution. Results indicate that the proposed distribution outperforms the existing Weibull distribution for modeling wind speed data in terms of minimum Akaike information criterion (AIC) and likelihood function. Thus, the exponentiated Weibull can be used as an alternative distribution that adequately describe the wind speed and thereby provide better representation of the potentials of wind energy

Maximum Likelihood Estimation of the Kumaraswamy Exponential Distribution with Applications

The Kumaraswamy exponential distribution, a generalization of the exponential, is developed as a model for problems in environmental studies, survival analysis and reliability. The estimation of parameters is approached by maximum likelihood and the observed information matrix is derived. The proposed models are applied to three real data sets

A Review of Optimization Approach to Power Flow Tracing in a Deregulated Power System

Power Flow Tracing (PFT) is known to be the best method in the allocation of charges to users of transmission systems, generators and loads, in a deregulated environment. The optimization approach to PFT produced better results than other methods because it considers the physical power flow results and electrical constraints of the system. A brief review of the optimal power flow concept, PFT techniques, and the deterministic and non-deterministic optimization methods applied to PFT are presented. The paper also highlighted the future trends of hybrid optimization approach to PFT. It is recommended that more research work should be directed on the hybrid optimization methods to solve PFT problems

Evaluation of the Community Cataract Surgical Services of a University Teaching Hospital Using Cataract Surgical Coverage in Nigeria

Background: Cataract is the leading cause of blindness in the world. An efficient and effective cataract surgical service is necessary to reduce the backlog of cataract blindness in the community. This study aims to determine the cataract surgical coverage among individuals aged 50 years and above residing in Esie and Arandun communities. This will serve as a measure of the impact of the cataract intervention programme provided by the University of Ilorin Teaching Hospital, Nigeria.Methods: The study was a population-based, cross sectional survey conducted from November to December, 2013. Cataract surgical services are provided by the University of Ilorin Teaching Hospital, Nigeria, at Esie and Arandun communities as out-reach centres. Seven hundred and fifty-five individuals aged 50 years and above residing in these communities had basic ocular examination done.Result: Out of the 765 subjects registered, 755(98.7%) were examined. Out of these, 38.4% were males and 61.6% were females. The prevalence of bilateral cataract blindness was 1.6%. The Cataract Surgical Coverage (eyes) at visual acuity < 3/60 for males and females were 52.3% and 51.2% respectively (X2=19.30, p=0.001), while the Cataract Surgical Coverage (person) at visual acuity less < 3/60 for males and females were 80.6% and 68.4% respectively (X2=2.10, p=0.147).Conclusion: The Cataract Surgical Coverage was high with a correspondingly low prevalence of cataract blindness in these communities. The availability of cataract surgical services via out-reach programmes bridges the gap between eye care-givers and the community.Keywords: Cataract Surgical Coverage, Cataract Surgical Services, Community, Evaluatio

Some Quality Indices of Gnetum Africanum (Afang) Leaves as Affected by Drying Methods

Gnetum africanum is a tropical plant with origin in the rain forest of Nigeria and contains valuable nutrients but susceptible to speedy spoilage due to its high moisture content. This necessitates its preservation, through drying, as it is not readily available for consumers in parts of Nigeria where it is not grown. This research, therefore, was carried out to evaluate the effect of three drying methods (solar drying, sun drying and oven drying) on some quality indices of Gnetum africanum leaves with a view to determine the most appropriate drying method for maximum nutrient retention. Fresh Gnetum africanum leaves were obtained from the local market, defoliated, washed, drained and sliced. The sliced vegetable was divided to four portions of 200g each. With the initial properties of the fresh vegetable (sample A) determined, samples B, C and, D were subjected to solar, sun and oven drying respectively. The properties evaluated were analyzed and the results showed that sun dried vegetable (sample C) had the least overall quality retention. Moreover, solar dried vegetable (sample B) had the highest quality retention in terms of protein (3.92%), fat content (6.67%) and carotene (6.10IU) while oven dried one (sample D) had the highest quality retention of crude fiber (0.63%), ash content (7.87%), carbohydrate (72.49%) and sensory properties (taste, colour, aroma and texture). These results indicated that drying, especially solar and oven drying can be used to preserve Gnetum africanum leaves with considerable retention in its nutritional and sensory properties

Household Welfare Effects of Stress-Tolerant Varieties in Northern Uganda

This study assessed the adoption of stress-tolerant varieties and their effect on household welfare, measured by net crop income per capita in Nwoya District, Uganda. The stress-tolerant varieties were considered to be climate-smart because they stabilise and increase crop income in the presence of climatic shocks. However, the uptake of the stress-tolerant varieties was still low in northern Uganda, due to bad past experience in terms of the performance of other improved varieties. Using data from a random sample of 585 households, a logistic model was estimated to assess the drivers for adoption of stress-tolerant varieties. In addition, a propensity score matching model was employed to assess causal effects. The second model was estimated because it controls for unobserved heterogeneity caused by self-selection bias. Results showed that adoption of stress-tolerant varieties was positively influenced by household size, access to information from non-governmental organizations (NGOs), the perception of future climate change, the number of years an individual had lived in the village, and the number and type of assets owned as an indicator of household well-being. Average treatment effect from results showed that stress-tolerant varieties can increase crop income within a range of United States Dollars (USD) 500–864 per hectare per year, representing an 18–32% increase in crop income. The findings offer justification for scaling up stress tolerant varieties among smallholder farmers in northern Uganda to improve their welfare

Refractive ocular conditions and reasons for spectacles renewal in a resource-limited economy

<p>Abstract</p> <p>Background</p> <p>Although a leading cause of visual impairment and a treatable cause of blindness globally, the pattern of refractive errors in many populations is unknown. This study determined the pattern of refractive ocular conditions, reasons for spectacles renewal and the effect of correction on refractive errors in a resource-limited community.</p> <p>Methods</p> <p>A retrospective review of case records of 1,413 consecutive patients seen in a private optometry practice, Nigeria between January 2006 and July 2007.</p> <p>Results</p> <p>A total number of 1,216 (86.1%) patients comprising of (486, 40%) males and (730, 60%) females with a mean age of 41.02 years SD 14.19 were analyzed. The age distribution peaked at peri-adolescent and the middle age years. The main ocular complaints were spectacles loss and discomfort (412, 33.9%), blurred near vision (399, 32.8%) and asthenopia (255, 20.9%). The mean duration of ocular symptoms before consultation was 2.05 years SD 1.92. The most common refractive errors include presbyopia (431, 35.3%), hyperopic astigmatism (240, 19.7%) and presbyopia with hyperopia (276, 22.7%). Only (59, 4.9%) had myopia. Following correction, there were reductions in magnitudes of the blind (VA<3/60) and visually impaired (VA<6/18-3/60) patients by (18, 58.1%) and (89, 81.7%) respectively. The main reasons for renewal of spectacles were broken lenses/frame/scratched lenses/lenses' falling off (47, 63.4%).</p> <p>Conclusions</p> <p>Adequate correction of refractive errors reduces visual impairment and avoidable blindness and to achieve optimal control of refractive errors in the community, services should be targeted at individuals in the peri-adolescent and the middle age years.</p