this research aims at investigating the amount of the application of servant leadership component in the libraries of isfahan state universities. the research method is descriptive survey study and the study population consists of managers and librarians of isfahan state universities in 2009-2010.the sample was estimated 111 by using cochran's formula. the random stratified sampling method was ...

In this article, we propose an improved estimator for finite population variance based on stratified sampling by using the auxiliary variable as well rank of variable. Expressions bias and mean square error estimators are derived up to first order approximation. Four real data sets used measure performances estimators. Moreover, a simulation study is also conducted observe efficiency proposed e...

In this paper we investigate the problem of estimation finite population mean using auxiliary information. The aim is to modify a separate ratio estimator by calibration approach for stratified random sampling. We use improve precision estimate parameter incorporating chi-square distance function minimize between original design weight and new weight. two constraints called equations find weigh...

this inverstigation is a quasi-experimental study comparing the effects of two methods of health education on student's knowledge and attitudes about aids. the target population consisted of 218 male undergraduates studying in payame noor university in saghez, iran. a random sample of 106 students was selected using sample random sampling method. the students were randomly divided into two...