Results 21 to 30 of about 3,268,717 (248)
Time variability studies with ROSAT [PDF]
International Astronomical Union Colloquium, 1995 AbstractAn overview over the mission of the X-ray astronomy satellite ROSAT (Röntgensatellit) is given with an emphasis on the first soft X-ray all-sky survey carried out with an imaging telescope. Several examples of time variability studies made possible by the all-sky survey are shown for active late-type stars. Two exceptional long-duration stellar
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Dual Transformation of Auxiliary Variables by Using Outliers in Stratified Random Sampling
MathematicsTo estimate the finite population variance of the study variable, this paper proposes an improved class of efficient estimators using different transformations. When both the minimum and maximum values of the auxiliary variable are known and the ranks of
Mohammed Ahmed Alomair, Umer Daraz
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Estimation of population mean using ranked set sampling in the presence of measurement errors
Kuwait Journal of ScienceRanked set sampling is widely acknowledged for its superior efficiency compared with simple random sampling. Only a small amount of work has been conducted using ranked set sampling when measurement errors are present.
Ahmadini A.A.H., Singh R., Raghav Y.S.
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Kinetic study of the convective drying of spearmint
Journal of the Saudi Society of Agricultural Sciences, 2014 This work presents the kinetic study of the convective drying of Tunisian spearmint in two manners. The traditional protocol which consists in carrying out drying experimental tests at constant temperatures 40–45–50–55 °C and a new protocol which ...
Mourad Ayadi +3 more
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The effect of various conductivity and viscosity models considering Brownian motion on nanofluids mixed convection flow and heat transfer [PDF]
Transport Phenomena in Nano and Micro Scales, 2016 In this paper the effect of using various models for conductivity and viscosity considering Brownian motion of nanoparticles is investigated. This study is numerically conducted inside a cavity full of Water-Al2O3 nanofluid at the case of mixed ...
H. R. Ehteram +4 more
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MathematicsThis article presents an improved class of efficient estimators aimed at estimating the finite population variance of the study variable. These estimators are especially useful when we have information about the minimum/maximum values of the auxiliary ...
Umer Daraz, Jinbiao Wu, Olayan Albalawi
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Statistica, 2014 This paper suggested a generalized class of estimators using information on two auxiliary va-riables and sampling fraction in simple random sampling.
Housila P. Singh +2 more
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Optimizing Finite Population Mean Estimation Using Simulation and Empirical Data
MathematicsTwo-phase sampling is an effective sampling approach that is useful in sample surveys when prior auxiliary information is not available. When two variables have an association, the ranks of the auxiliary variable are proportional to the study variable ...
Abdulaziz S. Alghamdi +1 more
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Pediatric Blood &Cancer, EarlyView.ABSTRACT Background Children with sickle cell disease (SCD) face multiple acute and chronic medical complications that may impact their quality of life as reported by patients themselves. Health‐related social needs (HRSNs), such as food and housing insecurity, are common in people with SCD, but the association between HRSNs and patient‐reported ...
Sarah J. Marks +5 more
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Enhanced estimation of population mean via exponential-type estimator using dual auxiliary inputs
Applied Mathematics in Science and EngineeringWithout having to interview every person, we may draw conclusions about the whole population by estimating the population mean, a fundamental summary statistic that is obtained from a sample.
Poonam Singh +2 more
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