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Interval Estimation of a P(X1 < X2) Model for Variables having General Inverse Exponential Form Distributions with Unknown Parameters
N. A. Mokhlis,
E. J. Ibrahim,
D. M. Gharieb
Issue:
Volume 7, Issue 4, July 2018
Pages:
132-138
Received:
28 February 2018
Accepted:
26 March 2018
Published:
3 May 2018
Abstract: In this article the interval estimation of a P(X1 < X2) model is discussed when X1 and X2are non-negative independent random variables, having general inverse exponential form distributions with different unknown parameters. Different interval estimators are derived, by applying different approaches. A simulation study is performed to compare the estimators obtained. The comparison is carried out on basis of average length, average coverage, and tail errors. The results are illustrated, using inverse Weibull distribution as an example of the general inverse exponential form distribution.
Abstract: In this article the interval estimation of a P(X1 < X2) model is discussed when X1 and X2are non-negative independent random variables, having general inverse exponential form distributions with different unknown parameters. Different interval estimators are derived, by applying different approaches. A simulation study is performed to compare the esti...
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Statistical Assessment of Employee’s Turnover and Its Causes; In the Case of Moret and Jiru Wereda, North Shoa, Amhara, Ethiopia
Issue:
Volume 7, Issue 4, July 2018
Pages:
139-146
Received:
17 March 2018
Accepted:
30 March 2018
Published:
3 May 2018
Abstract: The purpose of this study is to assess the employee turnover rate and cause in the case of Moret and Jiru Wereda. In light of this objective the study adopted quantitative and qualitative method of research approaches to test a series research hypothesis and subjective analysis respectively. Specifically, the study used survey of questionnaire analysis of Moret and Jiru Wereda. 326 respondents were selected based on stratified random sampling method. Data was then analyzed on quantitative basis using binary logistic regression and descriptive statistics; however, qualitative basis was used to subjective data. The result of this paper indicates that among the respondents 39.9 % of them do not want to quit their current job but majority of them (60.1%) said they seriously consider quitting their job very often. And furthermore the logistic regression found that Age of respondent, income of the respondents, experience of the respondents, educational level, satisfaction and incentive to be significantly related with turnover intension of the respondents and other factors such as gender, working hour and stress are found to be insignificant predictors of the turnover intension of the employees.
Abstract: The purpose of this study is to assess the employee turnover rate and cause in the case of Moret and Jiru Wereda. In light of this objective the study adopted quantitative and qualitative method of research approaches to test a series research hypothesis and subjective analysis respectively. Specifically, the study used survey of questionnaire anal...
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Bootstrap Confidence Interval for Model Based Sampling
Thomas Mageto,
John Motubwa
Issue:
Volume 7, Issue 4, July 2018
Pages:
147-155
Received:
28 March 2018
Accepted:
15 April 2018
Published:
18 May 2018
Abstract: The bootstrap approach to statistical inference in sample surveys is an area which has seen considerable development in the recent past. In model based approach to sample survey theory the main interest has been to overcome the problem of robustness under misspecifications. The bootstrap method under restrictive model specifications has been suggested by some authors as a way of achieving this. In this study, bootstrap and conventional confidence intervals for the population total in model based surveys using the simple random sampling without replacement are constructed. This is to provide a better measure of uncertainty associated with estimates of population total as compared to the corresponding rival confidence intervals under restrictive model. In order to achieve this, generated bootstrap simulations for the population of interest in assumed general model are used. The bootstrap method is less cumbersome to apply and in terms of coverage performance in 95% confidence interval, the bootstrap method is better compared to corresponding one under conventional methods. In terms of length, the confidences generated by the bootstrap method are much smaller as compared to the conventional counterparts. It is noted that the best performing confidence interval is one whose coverage rate is close to the true population total and its length small. The study research results provides great insight in constructing better confidence interval for the finite population total estimators.
Abstract: The bootstrap approach to statistical inference in sample surveys is an area which has seen considerable development in the recent past. In model based approach to sample survey theory the main interest has been to overcome the problem of robustness under misspecifications. The bootstrap method under restrictive model specifications has been sugges...
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Regularized Nonlinear Least Trimmed Squares Estimator in the Presence of Multicollinearity and Outliers
George Kemboi Kirui Keitany,
Ananda Omutokoh Kube,
Joseph Mutua Mutisya,
Fundi Daniel Muriithi
Issue:
Volume 7, Issue 4, July 2018
Pages:
156-162
Received:
17 April 2018
Accepted:
29 May 2018
Published:
29 June 2018
Abstract: This study proposes a regularized robust Nonlinear Least Trimmed squares estimator that relies on an Elastic net penalty in nonlinear regression. Regularization parameter selection was done using a robust cross-validation criterion and estimation through Newton Raphson iteration algorthm for the oprimal model coefficients. Monte Carlo simulation was conducted to verify the theoretical properties outlined in the methodology both for scenarios of presence and absence of multicollinearity and existence of outliers. The proposed procedure performed well compared to the NLS and NLTS in a viewpoint of yielding relatively lower values of MSE and Bias. Furthermore, a real data analysis demonstrated satisfactory performance of the suggested technique.
Abstract: This study proposes a regularized robust Nonlinear Least Trimmed squares estimator that relies on an Elastic net penalty in nonlinear regression. Regularization parameter selection was done using a robust cross-validation criterion and estimation through Newton Raphson iteration algorthm for the oprimal model coefficients. Monte Carlo simulation wa...
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Risk Factors of Road Traffic Accidents and Its Severity in North Shewa Zone, Amhara Region, Ethiopia
Issue:
Volume 7, Issue 4, July 2018
Pages:
163-166
Received:
8 June 2018
Accepted:
1 July 2018
Published:
23 July 2018
Abstract: Ethiopia is a country with the largest number of road traffic accidents and fatality rate. Pedestrians and the disabled, children and the aged in particular, are the major victims of these accidents. The severity of road traffic crashes is also likely to be much greater in Africa than anywhere else. The major objective of this study was to identify the major factors determining road traffic accidents and its severity in North Shewa Zone. The study is based on secondary data obtained from the police records of the accident cases in North Shewa Zone Police station from February 2013 - September 2016 G. C. The ordinal logistic regression analysis is applied to examine the association between severity levels of road traffic accidentsand human related variables, environmental and road related variables and vehicle related variables. Ordinal logistic regression analysis revealed that age of driver, driver-vehicle relationship, speed, alcohol use, chewing khat, educational level, driving experience and vehicle service year were found to be significant predictors for severity levels of road traffic accident.
Abstract: Ethiopia is a country with the largest number of road traffic accidents and fatality rate. Pedestrians and the disabled, children and the aged in particular, are the major victims of these accidents. The severity of road traffic crashes is also likely to be much greater in Africa than anywhere else. The major objective of this study was to identify...
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