SM Journal of Biometrics & Biostatistics

Archive Articles

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Characteristics of Photosynthetic Active Radiation (PAR) Through Statistical Analysis at Larnaca, Cyprus

Measurements of Photosynthetically Active Radiation (PAR) and global solar radiation at Larnaca (a coastal site in Cyprus) during the period 3013-2015 were used to investigate the seasonal characteristics of PAR and PAR/G ratio (PAR fraction or fFEC). PAR showed seasonal features with higher values in summer and lower values in winter. The annual mean values of PPFD and fFEC being 40.3 mol m-2 d-1 and 2.03 mol M J-1, respectively. Monthly average daily PAR increased from 19.1 mol m-2 d-1 (in December) to 59.6 mol m-2 d-1 (in June).The monthly daily average of fFEC remained almost constant throughout the year at Larnaca. The spatial variability of PAR was also investigated using measurements from other four sites with different climate characteristics. The annual mean daily PAR value ranged between 31.7 to 40.0mol m-2 d-1. The highest values are recorded in the coastal stations (Larnaca and Paralimni). The annual average value of fFEC at the five observation sites ranged from 1.82 mol MJ-1 to 2.03 mol MJ-1, in accordance to what is observed in most parts of the world. The highest appeared in the coastal sites of Larnaca and Paralimni due to the presence of high water vapour atmospheric concentrations. Elevation plays a significant role on the values of the above variables. As a general trend, fFEC followed the order Clear

Pashiardis S1, Kalogirou SA 1* and Pelengaris A2


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Stat LBP Feature Extraction and SIEDA Dimensionality Reduction and Classification for Face-Kin Verification

For man, several types of signals are available to recognize kinship, such as facial resemblance between families. Some studies show that we are able to recognize the kinship between a child's face and a face of a parent. The purpose of our work is to study the face-kin verification by using the Statistical Local Binary Patterns (Stat LBP) descriptor for the extraction of the local characteristics of facial images and the SIEDA (Side-Information based Exponential Discriminant Analysis) for the dimensionality reduction and classification of data. The extensive experimental evaluation carried out on Cornell kinshep database indicates that the proposed approach performs significantly better than state-of-the-art approaches.

Abdelmalik Ouamane


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A Didactic Investigation of Perfect Fit in Second-Order Confirmatory Factor Analysis: Exploratory Structural Equation Modeling and Bayesian Approaches

Confirmatory Factor Analysis (CFA) plays an integral role in establishing evidence for the validity of test scores. This study provides a didactic strategy on the systematic investigation of perfect model-data fit in CFA. Specific steps presented include (a) investigating the impact of sample size on model fit indices, power and Type II error, (b) demonstration of how Muthén and Asparouhov’s (2012) [1] ESEM approach is used to aid in evaluating the second-order factor model for simple structure, and (c) illustrating the tenability of Bayesian Structural Equation Modeling (BSEM) in resolving a non-positive definite matrix solution and in capturing the relationships between the measurement and latent variable parts of the second-order model in a way that provides an optimal tradeoff between simple structure and perfect model-data fit. The ESEM hierarchical approach identified loadings contradicting the original factor analytic results. Bayesian second-order CFA revealed that latent regressions were inflated in the original second-order CFA resulting in an in admissible solution due to a non-positive definite latent variable matrix. Respecification of the factor model using BSEM informed by the ESEM analysis eliminated the inadmissible solution and provided unbiased parameter estimates across sample sizes of N=100, 300, 600 and 1000.

Larry R Price


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Statistical Analysis and Inter Comparison of Solar UV and Global Radiation for Athalassa and Larnaca,Cyprus.

A statistical analysis and inter-comparison of the Ultraviolet Radiation (UVR) at two sites in Cyprus representing two different climate regimes of the island (Athalassa-inland plain vs Larnaca-coastal location) covering the period 2013-2015 is presented. Mean annual and mean monthly daily totals of the UV irradiation and their frequency distribution at both sites are computed and discussed. The total accumulated UV irradiation along an average year reaches 398 MJ m-2 at Athalassa and 494 MJ m-2 at Larnaca. During summer, the daily UV radiation exceeds the value of 1800 kJ m-2 at Athalassa and 2200 kJ m-2 at Larnaca. Linear relationships were established between UVR and global solar radiation, with the coefficient of determination close to 1. These hemispherical transmittance ( relationships indicate that UV irradiation corresponds to 5.9% and 6.8% of the horizontal global solar irradiation at the two sites, respectively. Four models were tested for the estimation of UVR and the best performed models were recalibrated according to the local conditions. Relationships between the clearness index (ktUV ) were also established. The annual ktUV is about 71% of kt Finally, the dependence of the UV/G ratio values to the solar elevation angle and clearness index was also examined. It can be concluded that the presence of clouds reduces less the UV component rather than the global solar radiation, due to the strong absorption of water in the near infrared spectrum.

Pashiardis S1, Kalogirou SA1 and Pelengaris A2


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Relationship between Fish Seed Production and Inland Fish Production of West Bengal, India

West Bengal is rich in Inland Fishery Resources. Ponds and tanks dominate with 90.62 percent water resources that are brought under culture. Overall 87.56% of total potential water resource is utilized for culture leaving another12.44% for yet to bring under culture. Fishermen constitute about 3.3 percent of total population of 91.3 million in West Bengal. Fisheries are next to agriculture in terms of providing employment and food supply. Fish is an important source of quality protein and cheaper in cost compared to other sources of animal protein. The government is continuously expanding areas under aquaculture. Therefore, there is a steady demand of fish seed for aquaculture. Fish seed is reported to be a constraint for expanding aquaculture in the state. In this communication, it is attempted to examine each of the trends of water area expansion for aquaculture, fish seed and inland fish production as well as demand and supply of fish based on secondary government statistics. The following trend lines were developed. (i) Prediction models on growth of pond f ishery(est)=1823.76X+1000,000; R2 = 0.97 (where Y is estimated pond fishery in ha and X is year. (ii)Demand of f ish: Y(est.) =15+0.2118X; R2 = 0.9967 (where Y is demand of fish in lakh ton and X is time in years). (iii) Supply of fish as Y(est.) =14.528+0.032X; R2=0.0606 (iv)Prediction Model for Fish Seed Production: Yest =8000+470.8X; R2=0. 864. v) Established relationship between inland fish production and fish seed production of the form Yest =1.9173+0.0007X; R2=0.6785, (where Y is Inland Fish Production and X is fish seed production). Finally, based on trend, appropriate strategy of water area expansion, fish seed production and supply & demand can be explored for sustainable aquaculture growth.

Ambalika Ghosh1, B K Mohapatra2 and Ajit Kumar Roy3*