1,220 research outputs found

    A Robust One-Sided Variability Control Chart

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    A new control charting technique to monitor the variability of any distribution is proposed. The simulation study shows that the new method outperforms all the existing methods in controlling the Type I error rates and it also has good power performance for all distributions considered in the study

    Tests for Correlation on Bivariate Non-Normal Data

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    Two statistics are considered to test the population correlation for non-normally distributed bivariate data. A simulation study shows that both statistics control type I error rates well for left-tailed tests and have reasonable power performance

    A Robust One-Sided Variability Control Chart

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    A new control charting technique to monitor the variability of any distribution is proposed. The simulation study shows that the new method outperforms all the existing methods in controlling the Type I error rates and it also has good power performance for all distributions considered in the study

    Right-tailed Testing of Variance for Non-Normal Distributions

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    A new test of variance for non-normal distribution with fewer restrictions than the current tests is proposed. Simulation study shows that the new test controls the Type I error rate well, and has power performance comparable to the competitors. In addition, it can be used without restrictions

    Improved Multiple Comparisons With The Best In Response Surface Methodology

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    A method to construct simultaneous confidence intervals about the difference in mean responses at the stationary point and at x for all x within a sphere with radius I R is proposed. Results of an efficiency study to compare the new method and the existing method by Moore and Sa (1999) are provided

    Relative significance of environmental factors affecting hydrogen production from landfilled refuse samples

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    The relative significance of 11 environmental factors on the apparent steady-state concentration of hydrogen (ASSCH2) achieved during anaerobic degradation of refuse collected from landfills was evaluated by using multiple regression analysis. Simple correlation analysis revealed a significant negative association of ASSCH2 with newsprint moisture content (NMO) and pH of the sample. Application of five different variable selection procedures, which are commonly used in multiple regression analyses, showed that NMO, amylase (AMY), esterase (EST), cellulose to lignin ratio (CLR), volatile solids (VS), and nitrogen content (NIT) were significantly associated with ASSCH2 simultaneously. The other five factors did not show any significant effect on ASSCH 2 in the presence of the six significant factors. Further analysis showed that the influence of AMY and EST on ASSCH2 was weak, hence they were not included in the regression model. CLR was also deleted from the final model because of the multicollinearity resulting from its high correlation with VS. The final model incorporated NMO, NMO2, VS2 and NIT2; it explained 95% of the total variability and predicted 98% of the observed ASSCH2. An assessment of the relative significance of the independent variables indicated that NMO contributed the most, followed by NMO2 and VS2, in that order, and the least by NIT2 towards ASSCH2. The NMO and NIT 2 showed an inhibitory effect on ASSCH2. The results indicated that maintaining optimum moisture, along with optimum organic loading, and nitrogen content in landfills is necessary to achieve and maintain a low ASSCH2 and maximize refuse methanogenesis.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

    A Review on Adverse Health Effects of Laboratory Volatile Solvents

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    The main objective of this review is to describe the health effects of commonly used laboratory volatile solvents in institutional laboratories. The most commonly used laboratory solvents such as petroleum ether, methanol, diethyl ether, benzene, acetone, mercury, etc. are having moderate to severe health effects on user. The mode of exposure and duration exposure of volatile solvents has greater effect on user. In a laboratory, when students/ researcher doing experiment unknowingly they are getting exposed with volatile solvents which has grater health (adverse) effect. The severity of the adverse effect varies based on type of exposure and duration exposure. The undesired effects of laboratory volatile solvents are sometime irreversible and may cause life-threatening problems

    Kinetic energy driven superconductivity in the electron doped cobaltate Nax_{x}CoO2y_{2}\cdot yH2_{2}O

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    Within the charge-spin separation fermion-spin theory, we have shown that the mechanism of superconductivity in the electron doped cobaltate Nax_{x}CoO2y_{2}\cdot yH2_{2}O is ascribed to its kinetic energy. The dressed fermions interact occurring directly through the kinetic energy by exchanging magnetic excitations. This interaction leads to a net attractive force between dressed fermions, then the electron Cooper pairs originating from the dressed fermion pairing state are due to the charge-spin recombination, and their condensation reveals the superconducting ground state. The superconducting transition temperature is identical to the dressed fermion pair transition temperature, and is suppressed to a lower temperature due to the strong magnetic frustration. The optimal superconducting transition temperature occurs in the electron doping concentration δ0.29\delta\approx 0.29, and then decreases for both underdoped and overdoped regimes, in qualitative agreement with the experimental results.Comment: 6 pages, 2 figs, corrected typos, accepted for publication in Commun. Theor. Phy
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