920 research outputs found
Estimation of Variance Using Known Coefficient of Variation and Median of an Auxiliary Variable
A modified ratio type variance estimator for estimating population variance of a study variable when the population median and coefficient of variation of an auxiliary variable are known is proposed. The bias and mean squared error of the proposed estimator are derived and conditions under which the proposed estimator performs better than the traditional ratio type variance estimators and modified ratio type variance estimators are obtained. Using a numerical study results show that the proposed estimator performs better than the traditional ratio type variance estimator and existing modified ratio type variance estimators
Controllable switching of vortex chirality in magnetic nanodisks by a field pulse
We propose a way of fast switching the chirality in a magnetic nanodisk by
applying a field pulse. To break the symmetry with respect to clockwise or
counterclockwise chirality a mask is added by which an inhomogeneous field
influences the vortex state of a nanodisk. Using numerical spin--lattice
simulations we demonstrate that chirality can be controllably switched by a
field pulse, whose intensity is above some critical value. A mathematical
definition for the chirality of an arbitrary shaped particle is proposed.Comment: REVTeX, 4 pages, 3 figure
Two Parameter Modified Ratio Estimators with Two Auxiliary Variables for Estimation of Finite Population Mean with Known Skewness, Kurtosis and Correlation Coefficient
Consider the two parameter modified ratio estimators for the estimation of finite population mean using the skewness, kurtosis and correlation coefficient of two auxiliary variables. The efficiencies of the proposed modified ratio estimators are assessed with that of the simple random sampling without replacement (SRSWOR) sample mean and some of the existing ratio estimators in terms of mean squared errors. The entire above is explained with the help of certain natural populations available in the literature
Median Based Modified Ratio Estimators with Known Quartiles of an Auxiliary Variable
New median based modified ratio estimators for estimating a finite population mean using quartiles and functions of an auxiliary variable are proposed. The bias and mean squared error of the proposed estimators are obtained and the mean squared error of the proposed estimators are compared with the usual simple random sampling without replacement (SRSWOR) sample mean, ratio estimator, a few existing modified ratio estimators, the linear regression estimator and median based ratio estimator for certain natural populations. A numerical study shows that the proposed estimators perform better than existing estimators; in addition, it is shown that the proposed median based modified ratio estimators outperform the ratio and modified ratio estimators as well as the linear regression estimator
A Mathematical model for the effect of Gastrin in humans using Fuzzy Rayleigh distribution
Gastrin is a potent stimulant of lower esophageal sphincter pressure in human. Several observations suggest that lower esophageal sphincter pressure is under the control of gastrin concentration. Injections of gastrin produce a marked increase in lower esophageal sphincter pressure. Various doses of synthetic gastrin-I significantly increased lower esophageal sphincter pressure. In this paper, we developed a mathematical model using the fuzzy Rayleigh distribution for the effects of gastrin on lower esophageal sphincter pressure in humans. Key Words: Cumulative damage model, Rayleigh distribution, Gastrin
Reduction of hexavalent chromium to trivalent chromium from tannery effluent using bacterial biomass
528-534Bioremediation is the most promising and cost-effective biological method widely used to clean up both contaminated soil and wastewater containing organic and inorganic pollutants. Ambur in Tamil Nadu is included in top ten Cr (VI) contaminated placeS in the world rated by Blacksmith Institute, U.S., in September 2006. Cr (VI) pollution in this area causes major health issues among the settled people, destruction of waterbodies, and pollutes the groundwater and agricultural lands. This work involves the biological treatment of Cr (VI) without producing any by-product. Bacterial culture tolerating high concentration isolated from the contaminated soil samples was collected from Cr (VI) contaminated sites of Ambur. The bacterial isolate was identified as 16s rRNA sequencing for Pseudomonasputida. Under the optimum parameter condition, reduction of Cr (VI) by isolated Pseudomonas putida was found to be 90% and Cr (VI) reduction by consortium of microbe to be 92%. Finally, reduced chromium was separated from the tannery effluent by chemical precipitation method
Worship Traditions in Pictorial Poetry
Praying to a deity for the sake of devotion is called worship. Tolkappiyam, the oldest book of Tamil, beautifully demonstrates that the deity has always been given priority in Tamil society. Even today, when we start an activity, it is customary for the Tamil community to start worshipping the deities of their clans and the deities of their choice. Worship arises from the lifestyle of the worshippers. Faith in God arises on the basis of the kind of social system a society has created and the system in which it receives its external necessities of life, such as food, clothing, and books. Just as the deities worshipped differed, so did the methods of worship in various ways. This can be understood from the literature created during the respective periods. That the worship of God was the first act of any action is evidenced by the fact that whatever kind of literature it may be, it began with the prayer to God. The pictorial poems, which are highlighted as one of the four poets sung together with the richness of literature combining painting, mathematics, and musical skills, are often sung in praise of God. Although there are many varieties of pictorial poems, among them, the types of pictorial poems that are in the form of bandham (a type) are the vehicles of God and are written in a form of worship associated with a God, which enriches the cult tradition of the Tamil community. In this way, the study identifies the pictorial poems arranged in the categories of Naga Bandham, Peacock Bandham, Anna Bandham, Vel Bandham, Ratha Bandham, Sivalinga Bandham, Malai Bandham, and Kamala Bandham
Intuitionistic Fuzzy Dot BCK/BCI - Algebras
In this paper we apply the concept of intuitionistic fuzzy set to dot BCK-sub algebra. The notion of an intuitionistic fuzzy dot BCK-sub algebra is introduced and some interesting properties are investigated. Then we study the homomorphism between intuitionistic fuzzy dot BCK- subalgebras
FUNGUS MEDIATED SYNTHESIS OF SILVER NANOPARTICLES USING ASPERGILLUS FLAVUS AND ITS ANTIBACTERIAL ACTIVITY AGAINST SELECTIVE FOOD BORNE PATHOGENS
In the present study, the aqueous extract of Aspergillus flavus was employed for the mycosynthesis of silver nanoparticles (AgNps). The fungal extract of A. flavus acts as a reducing agent for the synthesis of AgNps. The biologically synthesized AgNPs was well characterized using various techniques such as, UV–Visible spectrophotometer, TEM, EDX and XRD. The synthesized AgNPs was found to be spherical in shape with a size range between 10 to 40 nm, and presence of elemental silver was also confirmed by the EDX spectrum. The mycosynthesized AgNps showed great extent of antibacterial property against the selected food borne pathogenic strains. The results obtained revealed that the maximum antibacterial activity of AgNPs was found against B. subtilis followed by S. aureus. From the present study results, it is clear that the synthesized AgNPs possessing good antibacterial activity could be more effective in applications such as antibacterial food packaging materials. Keywords: Aspergillus flavus, AgNPs, Antibacterial activity, TE
Survival of tuberculosis patients treated under DOTS in a rural tuberculosis unit (TU), south India.
Objective: To estimate survival probabilities and identify risk factors for death of tuberculosis (TB) patients during
treatment period.
Methods: TB patients registered during May 1999 to December 2004 from a rural TB unit (TU) with a population of
580 000 in Tiruvallur district, South India, formed study population. Life table and Cox’s regression methods were used.
Results: Of the 3818 TB patients who were initiated on treatment, 96, 94 and 97% of category – I, II and III
respectively, were surviving after completion of treatment. Higher death rates were independently associated with
patient’s age (45 years), previous history of treatment, alcoholism and initial body weight (<35 kgs).
Conclusion: The survival probability was found to be similar in all patients irrespective of categorization. Necessary
actions need to be initiated in the programme to improve body weight and abstain from alcoholism
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