This study assesses the effect of population change on decade changes in the educational attainment level of ethnic (ancestry) populations in the United States. Our data derive from decennial censuses, NLMS, World Bank and INS. We find that changes in the share of ethnic populations with one or more years of post secondary schooling are associated with selected components of population change d...

In late 2003, nine populations of Sclerotinia homoeocarpa in Ontario Canada (seven of which had been previously sampled in early 1994, prior to the registration of sterol demethylation-inhibiting (DMI) fungicides for turf disease control in Canada) were sampled and tested for sensitivity to propiconazole. Four of the nine populations had not been treated with DMI fungicides during the interveni...

Many Operational Research (OR) techniques use historical data to populate model input parameters. Although the majority of these models take into account stochastic variation of the inputs, they do not necessarily take into account seasonal variations and other stochastic effects that might arise. One of the major applications of OR lies within healthcare, where ever increasing pressure on heal...

This paper analyzes the performances of the Spearman’s rho (SR) and Kendall’s tau (KT) with respect to samples drawn from bivariate normal and bivariate contaminated normal populations. The exact analytical formulae of the variance of SR and the covariance between SR and KT are obtained based on the Childs’s reduction formula for the quadrivariate normal positive orthant probabilities. Close fo...

One of the main consumers of energy in buildings are the HVAC systems intended to maintain the internal environment for the comfort and safety of the occupants. Occupant satisfaction, is influenced by many different factors, including air temperature, radiant temperature, humidity, the outdoor environment, activity levels and clothing. Occupant thermal comfort is traditionally measured by the P...

Estimated population is one of the most widely used products of demographic analyses. Population estimates are difficult to complete with accuracy for small areas because small areas can grow or decline rapidly, can change directions from growth to decline or from decline to growth, or undergo substantial changes in age, sex, race/ethnicity and other demographic characteristics. As a result, it...

In practice, the information regarding the population proportion possessing certain attribute is easily available see Jhajj et.al. (2006). For estimating the population mean Y of the study variable y, following Bahl and Tuteja (1991), a ratio-product type exponential estimator has been proposed by using the known information of population proportion possessing an attribute (highly correlated wi...

The growth of Aeromonas hydrophila and aerobic natural flora (APC) on gilthead seabream surfaces was evaluated during the refrigerated storage (21 days). The related growth curves were compared with those obtained by a conventional third order predictive model obtaining a low agreement between observed and predicted data (Root Mean Squared Error = 1.77 for Aeromonas hydrophila and 0.64 for APC)...

We propose an improved class of estimators in estimating the nite population variance, using the auxiliary information. The expressions for the bias and mean squared error of the proposed class of estimators are derived up to the rst order of approximation. Some estimators are also derived from a proposed class by allocating the suitable values of known parameters and identi ed as particular me...

In this paper we have proposed a class of ratio-cum-dual to ratio estimators for estimating population variance of the variable under study, using known values of some population parameters of auxiliary variable, which is available in the form of an attribute. The expressions for the bias and mean squared error of the proposed estimators have been derived upto the first order of approximation. ...