Statistical Research and Training Center - Statistical Centre of Iran
Journal of Statistical Research of Iran JSRI
1735-1294
11
1
2014
9
1
A Comparative Study of Performance of Adaptive Web Sampling and General Inverse Adaptive Sampling in Estimating Olive Production in Iran
1
23
EN
Ada
Afshar
adaaf@gmail.com
Hamidreza
Navvabpour
h.navvabpour@srtc.ac.ir
10.18869/acadpub.jsri.11.1.1
Nowadays, there is an increasing use of sampling methods in network and spatial populations. Although the most common link-tracing designs such as adaptive cluster sampling and snowball sampling have advantages over conventional sampling designs such as simple random sampling and cluster sampling, these designs still present many drawbacks. Adaptive web sampling is a new link-tracing design that overcomes some of the drawbacks. In this paper, after introducing adaptive web sampling design, an application of this method to estimate total production of olive in Iran using 1382 census data of agriculture is presented. Then by conducting a simulation study the performance of adaptive web sampling in estimating total olive production will be compared with that of general inverse adaptive sampling
Roa-Blackwell estimator, Markov chain Monte Carlo, link-tracing designs, adaptive web sampling, general inverse adaptive sampling
http://jsri.srtc.ac.ir/article-1-36-en.html
http://jsri.srtc.ac.ir/article-1-36-en.pdf
Statistical Research and Training Center - Statistical Centre of Iran
Journal of Statistical Research of Iran JSRI
1735-1294
11
1
2014
9
1
On the Reversed Average Intensity Order
25
39
EN
Majid
Rezaei
mjrezaei@birjand.ac.ir
Vahideh
Ahrari Khalaf
v_ahrary84@yahoo.com
10.18869/acadpub.jsri.11.1.25
Based on the increasing property of ratio of average reversed hazard rates of two non-negative random variables a new stochastic order for the sake of comparison of two lifetime distributions is proposed. This stochastic order admits some distinguishing properties. In order to illustrate the obtained results, a semi-parametric model which is called reverse hazard power and a mixture model of proportional reversed hazards are taken into account. Some examples are given to explain some facts.
Reversed hazard rate, stochastic order, mixture, reversed hazard power
http://jsri.srtc.ac.ir/article-1-37-en.html
http://jsri.srtc.ac.ir/article-1-37-en.pdf
Statistical Research and Training Center - Statistical Centre of Iran
Journal of Statistical Research of Iran JSRI
1735-1294
11
1
2014
9
1
Tsallis Maximum Entropy Lorenz Curves
41
56
EN
M.
Yaghoobi Avval Riabi
m_yagoobiawal@yahoo.com
G. H.
Mohtashami Borzadaran
gmb1334@yahoo.com
G. H.
Yari
yari@iust.ac.ir
10.18869/acadpub.jsri.11.1.41
In this paper, at first we derive a family of maximum Tsallis entropy distributions under optional side conditions on the mean income and the Gini index. Furthermore, corresponding with these distributions a family of Lorenz curves compatible with the optional side conditions is generated. Meanwhile, we show that our results reduce to Shannon entropy as $beta$ tends to one. Finally, by using actual data, we compare the maximum Tsallis entropy Lorenz curve with some parametric Lorenz curves.
entropy, Shannon entropy, maximum entropy principle, Lorenz Curve, Gini index, income distribution
http://jsri.srtc.ac.ir/article-1-38-en.html
http://jsri.srtc.ac.ir/article-1-38-en.pdf
Statistical Research and Training Center - Statistical Centre of Iran
Journal of Statistical Research of Iran JSRI
1735-1294
11
1
2014
9
1
The Ratio-type Estimators of Variance with Minimum Average Square Error
57
71
EN
MOhammadreza
Faghihi
m.faghihi@sbu.ac.ir
10.18869/acadpub.jsri.11.1.57
The ratio-type estimators have been introduced for estimating the mean and total population, but in recent years based on the ratio methods several estimators for population variance have been proposed. In this paper two families of estimators have been suggested and their approximation mean square error (MSE) have been developed. In addition, the efficiency of these variance estimators are compared. We also show that their performance is better than traditional ratio estimator. Finally, a computational approach to find the optimum values of parameters is introduced and by using rice fields data of Amol county of Iran, an empirical study is carried out to show that this approach is the best. In this manner, since the values of estimators MSE are approximated, to obtain the approximately unbiased estimator with minimum variance, average square error ASE is used.
Ratio estimator, ratio-type estimator, auxiliary information, variance estimation, mean square error, average square error
http://jsri.srtc.ac.ir/article-1-39-en.html
http://jsri.srtc.ac.ir/article-1-39-en.pdf
Statistical Research and Training Center - Statistical Centre of Iran
Journal of Statistical Research of Iran JSRI
1735-1294
11
1
2014
9
1
Pitman-Closeness of Preliminary Test and Some Classical Estimators Based on Records from Two-Parameter Exponential Distribution
73
96
EN
Elham
Mirfarah
mirfarah.elham@gmail.com
Jafar
Ahmadi
ahmadij@um.ac.ir
10.18869/acadpub.jsri.11.1.73
In this paper, we study the performance of estimators of parametersof two-parameter exponential distribution based on upper records.
The generalized likelihood ratio (GLR) test was used to generate preliminary test estimator (PTE) for both parameters. We have compared the proposed estimator with maximum likelihood (ML) and unbiased estimators (UE) under mean-squared error (MSE) and Pitman measure of closeness (PMC). Analytical as well as graphical methods are used to show the range of parameter in which PTE performs better than ML and UE. Results demonstrate that in the case of that prior information is not too far from its real value, the PTE is superior in compare with ML and UE based on both MSE and PMC criteria. The results of the paper will be useful in estimation with record data in life testing experiments.
Preliminary test estimator, maximum likelihood estimator, unbiased estimator, mean-squared error, Pitman measure of closeness, record data
http://jsri.srtc.ac.ir/article-1-40-en.html
http://jsri.srtc.ac.ir/article-1-40-en.pdf
Statistical Research and Training Center - Statistical Centre of Iran
Journal of Statistical Research of Iran JSRI
1735-1294
11
1
2014
9
1
A New Modified Weibull Distribution and Its Applications
97
118
EN
A.
Doostmoradi
ali.dostmoradii@gmail.com
M. R.
Zadkarami
zadkarami@yahoo.com
A.
Roshani Sheykhabad
amin.roshani@hotmail.com
10.18869/acadpub.jsri.11.1.97
In this paper we introduce a four-parameter generalized Weibull distribution. This new distribution has a more general form of failure rate function. It is more general for modeling than six ageing classes of life distributions with appropriate choices of parameter values, so it can display decreasing, increasing, bathtub shaped, unimodal, increasing-decreasing increasing and decreasing-increasing-decreasing failure rates. The new distribution has also a bimodal density function. The moments are obtained and the method of maximum likelihood is used to estimate the model parameters. Also, the observed information matrix is obtained. Two applications are presented to illustrate the advantage of the proposed distribution.
Beta distribution, exponentiated Weibull distribution, generalized exponentiated Weibull distribution, modified Weibull distribution, maximum likelihood estimation, observed information matrix.
http://jsri.srtc.ac.ir/article-1-44-en.html
http://jsri.srtc.ac.ir/article-1-44-en.pdf