Model Assisted Statistics and Applications - Volume 12, issue 2

Authors: Prasad, Shakti

Article Type: Research Article

Abstract: Twenty exponential type estimators with imputation have been suggested to overcome the problem of missing data for a study variable in sample surveys. It has been shown that the suggested estimators are more efficient than the mean method of imputation, ratio method of imputation, regression method of imputation and the estimators are given by Singh and Horn (2000), Singh and Deo (2003), Singh (2009), Gira (2015) and Singh et al. (2016). The biases and their mean square errors of the suggested estimators are derived. Simulation studies are also demonstrated for comparing the performances of the suggested estimators.

Keywords: Imputation methods, missing data, bias, mean square error (MSE), percent relative efficiency2000 AMS Classification: 62D05

DOI: 10.3233/MAS-170386

Citation: Model Assisted Statistics and Applications, vol. 12, no. 2, pp. 95-106, 2017

Authors: Koshti, Rohan Dilip | Kamalja, Kirtee Kiran

Article Type: Research Article

Abstract: Concept of Ranked Set Sampling is applicable whenever ranking on a set of sampling units can be done easily by a judgment method or based on an auxiliary variable. In this work, we consider a study variable Y correlated with auxiliary variable X which is used to rank the sampling units. Further ( X , Y ) is assumed to have bivariate Lomax distribution. We obtain an unbiased estimator of scale parameter of study variable Y based on ranked set sample and censored ranked set sample. Efficiency …comparison of these estimators with usual SRS estimator is also performed. Show more

Keywords: Ranked set sampling, censored Ranked Set Sampling, bivariate Lomax distribution, concomitants of order statistics, Best linear unbiased estimator

DOI: 10.3233/MAS-170387

Citation: Model Assisted Statistics and Applications, vol. 12, no. 2, pp. 107-113, 2017

Authors: Cahoy, Dexter O. | Minkabo, Sharifa

Article Type: Research Article

Abstract: We propose point estimators for the three-parameter (location, scale, and the fractional parameter) variant distributions generated by a Wright function. We also provide uncertainty quantification procedures for the proposed point estimators under certain conditions. The class of densities includes the three-parameter one-sided and the three-parameter symmetric bimodal M -Wright family of distributions. The one-sided family naturally generalizes the Airy and half-normal models. The symmetric class includes the symmetric Airy and normal or Gaussian densities. The proposed interval estimator for the scale parameter outperformed the estimator derived in Cahoy (2012) when the location parameter is zero. We obtain the …asymptotic covariance structure for the scale and fractional parameter estimators, which allows estimation of the correlation. The coverage probabilities of the interval estimators slightly depend on the proposed location parameter estimators. For the symmetric case, the sample mean (or median) is favored than the median (or mean) when the fractional parameter is greater (or lesser) than 0.39106 in terms of their asymptotic relative efficiency. The estimation algorithms were tested using synthetic data and were compared with their bootstrap counterparts. The proposed inference procedures were demonstrated on age and height data. Show more

Keywords: Gaussian, skew-normal, M-Wright, Mittag-Leffler, skew-Laplace, Airy, skew-symmetric, Major Leaque Baseball, children heights

DOI: 10.3233/MAS-170388

Citation: Model Assisted Statistics and Applications, vol. 12, no. 2, pp. 115-125, 2017

Authors: Gupta, Omprakash K. | Arekar, Kirti | Desphande, Bharati | Sherin, Prem

Article Type: Research Article

Abstract: With the Indian economy growing rapidly, the rate of employment has seen a tremendous upward rise. The expansion of boundaries and the credible usage of internet have heightened the demands for highly skilled managers and professionals. An opinion poll of HR professionals from various countries reveals a unanimous view that rampant job hopping has become a culture across industries (Khatr, Chong & Budhwar, 2001: 54). A number of earlier studies suggest that the length of service in a job can be used to estimate the levels of worker job satisfaction. The assumption is that the less satisfied workers tend to …resign while the more satisfied workers tend to remain in a job. This situation should result in a higher average level of satisfaction reported by employees who have been in a given organization for a greater period of time. Kim, Price Mueller & Watson (1996) Price and Mueller’s Model is a comprehensive employee turnover model which captures a 360 degree view of the determinants of employee turnover. It comprises of Individual determinants, Structural determinants, Environmental determinants, Process variables and correlates. In this paper, we initially studied the impact of age, salary and marital status of the correlates on structural and process determinants, and we further consider studying the moderating effect of eight variables of structural and two variables of process determinants in the Indian context by using Structural equation modeling. Show more

Keywords: Structural determinants, process determinants, job satisfaction, organization commitment, autonomy, job stress

DOI: 10.3233/MAS-170389

Citation: Model Assisted Statistics and Applications, vol. 12, no. 2, pp. 127-136, 2017

Authors: Chandra, N. | Rathaur, V.K.

Article Type: Research Article

Abstract: In this article we consider the Bayesian and Maximum Likelihood (ML) estimation of augmented strength of a system for the generalized case of the proposed Augmentation Strategy Plan (ASP). ASP has interesting applications in stress strength reliability. The Bayes estimation is performed by assuming non-informative (uniform and Jeffreys) types of priors under two different loss functions i.e. squared error loss function (SELF) and LINEX loss function (LLF) for better comprehension purpose. It is assumed that the strength (X ) and the imposed stress (Y ) follow independent and non-identical two parameter gamma distributions. The MCMC simulation …techniques are employed to study the comparison between the ML and Bayes estimators of augmented strength reliability on the basis of their mean square errors (mse) and absolute biases. The proposed estimators are validated by Monte Carlo simulated as well as real data sets. Show more

Keywords: Augmented strength reliability, gamma distribution, Bayes estimator, non-informative prior, Metropolis-Hasting algorithm, Markov chain monte carlo simulation

DOI: 10.3233/MAS-170390

Citation: Model Assisted Statistics and Applications, vol. 12, no. 2, pp. 137-150, 2017

Authors: Kristiani, Farah | Samat, Nor Azah | bin Ab Ghani, Sazelli

Article Type: Research Article

Abstract: Dengue is one of the most dangerous vector-borne infectious diseases in the world which are fatal in many cases due to inefficient treatment. Although the relative risk estimations of dengue transmission are available for Bandung, one of the most populous cities in Indonesia, dengue cases especially among young people have increased rapidly. However, the age factor has not yet been included in these estimations. Because specific treatment and prevention depend on age, this factor must be considered in any dengue transmission model. In this article, the authors classify dengue cases in Bandung into juveniles and adults. Each group is analyzed …by SIR-SI model to estimate the relative risk of dengue transmission as an indirect transmission disease which takes into account the stochastic factor. This model also considers a spatial correlation which affects dengue distribution in a specific area for a particular age group. The results of the analysis show that some areas in Bandung have medium to very high dengue risk, especially for the juvenile group. It is expected that The Health Department of Bandung will focus dengue transmission prevention programs more intensively on this group. In further research, if the data needed are available, this model can be applied to other cities in Indonesia. Show more

Keywords: Age, Bandung, Bayesian, dengue, relative risk

DOI: 10.3233/MAS-170391

Citation: Model Assisted Statistics and Applications, vol. 12, no. 2, pp. 151-161, 2017

Authors: Singh, Housila P. | Gorey, Swarangi M.

Article Type: Research Article

Abstract: This paper considers the problem of estimating the population total of the sensitive variable under a unified approach. Odumade and Singh (2008) have suggested a forced quantitative randomized response model and then suggested an unbiased estimator of the population total Y of the sensitive variable y . It is observed that the optimum estimator of the population total Y due to Odumade and Singh (2008) depends on the unknown population parameter under investigation which lacks the practical utility. To overcome this drawback Odumade and Singh (2008) suggested another unbiased estimator of the …population total of the sensitive variable based on two independent samples which causes the increase in the cost. Keeping this in view we define an alternative randomized response procedure and hence the estimator of the population total of the sensitive variable based on one sample only which is free from such limitation and more efficient than the Odumade and Singh (2008) estimator. The relative efficiency of the proposed estimator with respect to Bar-Lev et al. (2004) and Odumade and Singh (2008) estimators are examined through numerical illustration. Show more

Keywords: Sensitive quantitative variable, randomized response technique, population total, varianceAMS Classification: 62D05

DOI: 10.3233/MAS-170392

Citation: Model Assisted Statistics and Applications, vol. 12, no. 2, pp. 163-177, 2017

Authors: Joshy, C.G. | Balakrishna, N.

Article Type: Research Article

Abstract: This paper deals with blocking of first order response surface model with interaction under equi- and auto-correlated error structure. The conditions for orthogonal blocking, orthogonal estimation of the parameters and constancy of the variance of the predicted response have been derived for the proposed model. D-optimality criterion for orthogonally blocked first order response surface designs with interaction has also been discussed. A method of construction of design satisfying the derived conditions is given under the proposed model along with an illustration.

Keywords: Blocking in response surface model, orthogonal estimation, equi-correlated errors, auto-correlated errors

DOI: 10.3233/MAS-170393

Citation: Model Assisted Statistics and Applications, vol. 12, no. 2, pp. 179-191, 2017