The application of ranked set sampling (RSS) techniques to data from a dichotomous population is currently an active research topic, and it has been shown that balanced RSS leads to improvement in precision over simple random sampling (SRS) for estimation of a population proportion. Balanced RSS, however, is not in general optimal in terms of variance reduction for this setting. The objective o...

An almost unbiased estimator using known value of some population parameter(s) is proposed. Under simple random sampling without replacement (SRSWOR) scheme the expressions for bias and mean square error (MSE) are derived. Numerical illustrations are given.

simple harmonizable processes (shp) introduced by soltani and parvardeh (2006) are a large class of nonstationary processes which includes stationary and periodically correlated (pc) processes. detection and estimation of shp structure are important problems when dealing with nonstationary data. in this paper, we study the spectral properties of simple processes and propose a method to detect a...

the purpose of this study was to compare symptoms of ptsd among war affected people and employees in the fire station. totally, 60 people affected by war and 60 fire workers were selected using simple random sampling. by completing pcl inventory, samples of ptsd were characterized. data was analysed through spss software by independent t-test. as the results showed, severity of ptsd symptoms am...

this paper aims to consider the relationship between social capital and social responsibility in islamic azad university – firouzkouh branch. the population of research all faculty members, managers and experts employed in islamic azad university - firouzkouh branch. the sample sizeincludes 157 peopledetermined by jeris-morgan formula using the stratified random sampling method. firstly, a ques...

Introduction: An evaluation of the curriculum elementscan be recognized as a necessity in curriculum dynamic andimprovement. This study aimed at evaluating five main elementsof a physiopathology curriculum in internal medicine (objectives,content, methods, evaluation, and management).Method: The present study is of a descriptive-analytical type, andthe study population consisted of a total of 4...

Because of high costs or complex logistics, scientific populations cannot be measured entirely and must be sampled. Accepted scientific practice holds that sample selection be based on statistical principles to assure objectivity when estimating totals and variances. Probability sampling--obtaining samples with known probabilities--is the only method that assures these results. However, probabi...