Support Vector Regression Based S-transform for Prediction of Single and Multiple Power Quality Disturbances

This paper presents a novel approach using Support Vector Regression (SVR) based S-transform to predict the classes of single and multiple power quality disturbances in a three-phase industrial power system. Most of the power quality disturbances recorded in an industrial power system are non-stationary and comprise of multiple power quality disturbances that coexist together for only a short duration in time due to the contribution of the network impedances and types of customers’ connected loads. The ability to detect and predict all the types of power quality disturbances encrypted in a voltage signal is vital in the analyses on the causes of the power quality disturbances and in the identification of incipient fault in the networks. In this paper, the performances of two types of SVR based S-transform, the non-linear radial basis function (RBF) SVR based S-transform and the multilayer perceptron (MLP) SVR based S-transform, were compared for their abilities in making prediction for the classes of single and multiple power quality disturbances. The results for the analyses of 651 numbers of single and multiple voltage disturbances gave prediction accuracies of 86.1% (MLP SVR) and 93.9% (RBF SVR) respectively. Keywords: Power Quality, Power Quality Prediction, S-transform, SVM, SV

A New Weighting Scheme in Weighted Markov Model for Predicting the Probability of Drought Episodes

Drought is a complex stochastic natural hazard caused by prolonged shortage of rainfall. Several environmental factors are involved in determining drought classes at the specific monitoring station. Therefore, efficient sequence processing techniques are required to explore and predict the periodic information about the various episodes of drought classes. In this study, we proposed a new weighting scheme to predict the probability of various drought classes under Weighted Markov Chain (WMC) model. We provide a standardized scheme of weights for ordinal sequences of drought classifications by normalizing squared weighted Cohen Kappa. Illustrations of the proposed scheme are given by including temporal ordinal data on drought classes determined by the standardized precipitation temperature index (SPTI). Experimental results show that the proposed weighting scheme for WMC model is sufficiently flexible to address actual changes in drought classifications by restructuring the transient behavior of a Markov chain. In summary, this paper proposes a new weighting scheme to improve the accuracy of the WMC, specifically in the field of hydrology

Studies on serum macro and micro minerals status in repeat breeder and normal cyclic Nili-Ravi buffaloes and their treatment strategies

The present study was carried out with the objective to know the calcium (Ca), inorganic phosphorus (P), magnesium (Mg), copper (Cu), iron (Fe) and zinc (Zn) concentrations in serum of repeat breeder and normal cyclic buffaloes during oestrus. On the day of estrus, blood samples were collected from 35 buffaloes with a history of repeat breeding (RB) and 35 normal cycling (NC) buffaloes for mineral estimation. In the second part of the study, 35 repeat breeder (RBS) buffaloes were treated with a mineral mixture given orally for 10 days at the dosage rate of 150 g per day whereas other 35 repeat breeder buffaloes were given no mineral mixture (RBC). The overall pregnancy rate as well as 1st, 2nd and 3rd service pregnancy rate was calculated. The serum calcium, inorganic phosphorus, magnesium, copper, iron and zinc concentrations were significantly lower (P < 0.01) in RB buffaloes as compared to NC buffaloes. Sodium concentrations differed non-significantly between repeat breeder and normal cyclic buffaloes. Repeat breeder buffaloes (RBS) when fed orally 150 g per day of the mineral mixture for 10 days, the 1st, 2nd and 3rd service pregnancy rates were 42, 25 and 20%, while, overall pregnancy rate in these animals was 87%; whereas in repeat breeder control buffaloes, the overall pregnancy rate was 21%. In conclusion, the concentrations of macro and micro minerals were significantly lower in repeat breeder buffaloes and mineral mixtures should be added in the food stuff to improve reproductive efficiency of repeat breeder buffaloes. Keywords: Buffalo, repeat breeder, minerals, pregnancy rateAfrican Journal of Biotechnology, Vol. 13(10), pp. 1143-1146, 5 March, 201

Drop size in a liquid pulsed sieve-plate extraction column

Peer reviewedPublisher PD

N′-[(E)-(1-Methyl-1H-pyrrol-2-yl)methyl­idene]pyridine-4-carbohydrazide. Corrigendum

Corrigendum to Acta Cryst. (2010), E66, o1881

Lumbar morphometry: A study of lumbar vertebrae from a Pakistani population using computed tomography scans

Study design: A cross-sectional study.Purpose: To describe the characteristics of lumbar vertebrae of Pakistani patients reporting at a tertiary care hospital and compare with studies from other populations.Overview of literature: Several studies have been conducted to determine morphometry of lumbar vertebrae. Most of the studies involve Caucasian populations, still data on other populations still sparse. This is the first study describing lumbar morphometry of a Pakistani population.Methods: An observational study was conducted based on a review of thin-cut (3 mm) computed topographic images of lumbar vertebrae. Two-hundred and twenty vertebrae from forty-nine patients were studied, and various dimensions were analyzed.Results: Generally, the size of the vertebrae, vertebral canals and recesses were found to be greater in male patients. The difference was statistically significant for transverse and anteroposterior diameters of the vertebral bodies and sagittal diameter of pedicles on the left side (p\u3c0.05). Comparison of populations revealed statistically significant differences in pedicle dimensions between Pakistani population and others.Conclusions: This study provides anatomical knowledge of the lumbar region in a sample population of Pakistan. There were significant differences in various dimensions of lumbar vertebrae between female and male patients. This would prove to be critical for performing a safe operation

Temperature Dependent Piezoelectric Properties of Lead-Free (1-x)K0.6Na0.4NbO3–xBiFeO3 Ceramics

(1-x)K0.4Na0.6NbO3–xBiFeO3 lead-free piezoelectric ceramics were successfully prepared in a single perovskite phase using the conventional solid-state synthesis. Relative permittivity (εr) as a function of temperature indicated that small additions of BiFeO3 not only broadened and lowered the cubic to tetragonal phase transition (TC) but also shifted the tetragonal to orthorhombic phase transition (TO–T) toward room temperature (RT). Ceramics with x = 1 mol.% showed optimum properties with small and large signal piezoelectric coefficient, d33 = 182 pC/N and d∗33 = 250 pm/V, respectively, electromechanical coupling coefficient, kp = 50%, and TC = 355°C. kp varied by ∼5% from RT to 90°C, while d∗33 showed a variation of ∼15% from RT to 75°C, indicating that piezoelectric properties were stable with temperature in the orthorhombic phase field. However, above the onset of TO–T, the properties monotonically degraded in the tetragonal phase field as TC was approached