Walid Ahmad Abu-Dayyeh
Author's books
Maximum likelihood estimator of the shape parameter of the weibull distribution using ranked set sampling
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Article
| STATISTICA & APPLICAZIONI - 2013 - 2


Year:
2014
In this paper, we will consider the (maximum likelihood estimators) MLEs of the shape parameter p of the Weibull distribution...
Estimation of the variance for logistic distribution under ranked set sampling and simple random sampling: a comparative study
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digital
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Article
| STATISTICA & APPLICAZIONI - 2012 - 2


Year:
2012
SUMMARY
The logistic distribution is applicable in many area of research. In this study, several estimators of
the variance when the location parameter is known and unknown are considered when data are
gathered under simple random sampling (SRS) and ranked set sampling (RSS). For some estimators
considered, the bias and mean square error (MSE) are not gotten in closed form. Using Monte Carlo
simulations, comparison of these estimators is made based on biases, MSE and efficiency. When
the estimators are compared, it is found that estimators based on maximum likelihood method are
more efficient than other estimators considered, under both SRS and RSS. However, estimators
based on RSS have more advantages over those based on SRS.
Keywords: Logistic Distribution, Ranked set Sampling, Simple Random Sampling, Variance, Estimations.
Estimation of = P(X>Y) using ranked set sampling
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digital
format:
Article
| STATISTICA & APPLICAZIONI - 2010 - 2


Year:
2010
SUMMARY
Nonparametric-type estimation of ¼ PðX > YÞ, based on ranked set sampling (RSS) technique
with concomitant random variable, is considered. The maximum likelihood estimation (MLE) of is
also considered using RSS and median ranked set sampling (MRSS) techniques with concomitant
random variable. The estimators obtained are compared to their counterparts based on simple random
sampling (SRS) using bias and mean square error (MSE). It appears that the suggested nonparametric
estimator based on RSS is more efficient than that based on SRS and the MLE based on
MRSS is more efficient than the MLE based on RSS which is in turn more efficient than the MLE
based on SRS.
Keywords: Simple Random Sampling, Ranked Set Sampling, Median Ranked Set Sampling, Nonparametric
Estimation; Maximum Likelihood Estimation, Mean Square Error.
RIASSUNTO
La stima non parametrica di ¼ PðX > YÞ basata sulla tecnica del Ranked Set Sampling (RSS)
con variabile concomitante e` considerata preliminarmente. Successivamente viene trattata la Stima
di Massima Verosimiglianza (MLE) di nel caso Normale usando sia RSS sia il Median Ranked
Set Sampling (MRSS) con variabile concomitante. Gli stimatori ottenuti sono confrontati con quelli
basati sul Simple Random Sample (SRS) usando il bias e l’errore quadratico medio (MSE). Emerge
che lo stimatore non parametrico proposto basato su RSS e`piu` efficiente di quello basato su SRS e
lo stimatore MLE basato su MRSS e`piu` efficiente di quello MLE basato su RSS che a sua volta risulta
piu` efficiente di quello MLE basato su SRS.
Comparison of several confidence intervals for normal distribution with known coefficient of variation
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digital
format:
Article
| STATISTICA & APPLICAZIONI - 2010 - 1


Year:
2010
In this paper, we consider the problem of constructing confidence intervals for the normal population mean when the coefficient of variation is known. We obtain 13 confidence intervals using different pivots. Also we conduct a simulation study to compare the expectations as well as the standard deviations of the intervals lengths.
Keywords: Coefficient of Variation, Normal Distribution, Pivotal Method, Confidence Interval.