Estimation using hybrid censored data from a generalized inverted exponential distribution

ABSTRACT

We consider point and interval estimation of the unknown parameters of a generalized inverted exponential distribution in the presence of hybrid censoring. The maximum likelihood estimates are obtained using EM algorithm. We then compute Fisher information matrix using the missing value principle. Bayes estimates are derived under squared error and general entropy loss functions. Furthermore, approximate Bayes estimates are obtained using Tierney and Kadane method as well as using importance sampling approach. Asymptotic and highest posterior density intervals are also constructed. Proposed estimates are compared numerically using Monte Carlo simulations and a real data set is analyzed for illustrative purposes.     

Estimating a positive normal mean

Let X ₁, X ₂, ..., X _n be a random sample from a normal population with mean μ and variance σ ². In many real life situations, specially in lifetime or reliability estimation, the parameter μ is known a priori to lie in an interval [a, ∞). This makes the usual maximum likelihood estimator (MLE) ̄ an inadmissible estimator of μ with respect to the squared error loss. This is due to the fact that it may take values outside the parameter space. Katz (1961) and Gupta and Rohatgi (1980) proposed estimators which lie completely in the given interval. In this paper we derive some new estimators for μ and present a comparative study of the risk performance of these estimators. Both the known and unknown variance cases have been explored. The new estimators are shown to have superior risk performance over the existing ones over large portions of the parameter space.     

Maternal input and infants’ response to infant‐directed speech

Caregivers typically use an exaggerated speech register known as infant‐directed speech (IDS) in communication with infants. Infants prefer IDS over adult‐directed speech (ADS) and IDS is functionally relevant in infant‐directed communication. We examined interactions among maternal IDS quality, infants’ preference for IDS over ADS, and the functional relevance of IDS at 6 and 13 months. While 6‐month‐olds showed a preference for IDS over ADS, 13‐month‐olds did not. Differences in gaze following behavior triggered by speech register (IDS vs. ADS) were found in both age groups. The degree of infants’ preference for IDS (relative to ADS) was linked to the quality of maternal IDS infants were exposed to. No such relationship was found between gaze following behavior and maternal IDS quality and infants’ IDS preference. The results speak to a dynamic interaction between infants’ preference for different kinds of social signals and the social cues available to them.     

The Human Capital Model or Location! Location! Location!? The Gender-Based Wage Gap in the Federal Civil Service

Gender Issues - Theoretically, the human capital variables, education and experience, and occupations for which women and men qualify explain the gender-based wage gap in the federal civil service....     

The Human Capital Model and Federal Employees’ Pay: Gender, Veteran Status, and Occupation

Do the human capital variables education and experience, and the chosen occupations for which male and female veterans and nonveterans qualify affect pay in the federal civil service? Are the strength and direction of relationships similar before and after the wars in Iraq and Afghanistan? When compared to federal employees in other agencies, are differences in pay based on gender and veteran status the same for those who work for the Department of Defense (DOD)? This is an ordinary least squares regression analysis of Office of Personnel Management records for a 1 % random sample of federal employees in 2000 and 2009. These regression models based on the Human Capital Model, data from years before and after the wars in Iraq and Afghanistan, and separate analyses for DOD and non-DOD agencies differ from earlier analyses. Whether or not an employee works for the DOD, years of education and experience are significantly related to pay. In addition, between 2000 and 2009 the gender-based wage gap for nonveterans decreased while the gap between the pay of the reference group and male and female veterans grew for federal employees who did not work for the DOD. In the same years, for DOD employees there are fewer differences in pay based on veteran status and gender and race. With some exceptions for the DOD, the significant positive relationships between pay and occupation became significant negative relationships when the pay of women in each occupation was analyzed.     

Estimation and prediction of Marshall–Olkin extended exponential distribution under progressively type-II censored data

In this paper, we consider Marshall–Olkin extended exponential (MOEE) distribution which is capable of modelling various shapes of failure rates and aging criteria. The purpose of this paper is three fold. First, we derive the maximum likelihood estimators of the unknown parameters and the observed the Fisher information matrix from progressively type-II censored data. Next, the Bayes estimates are evaluated by applying Lindley’s approximation method and Markov Chain Monte Carlo method under the squared error loss function. We have performed a simulation study in order to compare the proposed Bayes estimators with the maximum likelihood estimators. We also compute 95% asymptotic confidence interval and symmetric credible interval along with the coverage probability. Third, we consider one-sample and two-sample prediction problems based on the observed sample and provide appropriate predictive intervals under classical as well as Bayesian framework. Finally, we analyse a real data set to illustrate the results derived.     

Estimation of the shape parameter of a Pareto distribution

We consider the problem of estimating the shape parameter of a Pareto distribution with unknown scale under an arbitrary strictly bowl-shaped loss function. Classes of estimators improving upon minimum risk equivariant estimator are derived by adopting Stein, Brown, and Kubokawa techniques. The classes of estimators are shown to include some known procedures such as Stein-type and Brewster and Zidek-type estimators from literature. We also provide risk plots of proposed estimators for illustration purpose.     

Early Word Recognition in Sentence Context: French and English 24‐Month‐Olds' Sensitivity to Sentence‐Medial Mispronunciations and Assimilations

Recent work has shown that young children can use fine phonetic detail during the recognition of isolated and sentence‐final words from early in lexical development. The present study investigates 24‐month‐olds' word recognition in sentence‐medial position in two experiments using an Intermodal Preferential Looking paradigm. In Experiment 1, French toddlers detect word‐final voicing mispronunciations (e.g., bu z [by z ] for bu s [by s ] “bus”), and they compensate for native voicing assimilations (e.g., bu z d evant toi [bu zd ?vɑ?twa] “bus in front of you”) in the middle of sentences. Similarly, English toddlers detect word‐final voicing mispronunciations (e.g., shee b for shee p ) in Experiment 2, but they do not compensate for illicit voicing assimilations (e.g., shee b th ere). Thus, French and English 24‐month‐olds can take into account fine phonetic detail even if words are presented in the middle of sentences, and French toddlers show language‐specific compensation abilities for pronunciation variation caused by native voicing assimilation.     

Utilizing grassroots workers in family planning programs in India: prospects and problems

In order to rapidly expand the network of delivery systems and speed up the process of acceptance of family planning messages and methods, a shift took place in the Indian family planning program from the bureaucratic "clinical" approach to the people oriented "extension" approach. As a result, there is an increasing emphasis on moving the family planning efforts closer to the grassroots level. A key methodological issue centers on the proper selection, cultural acceptability, and the effectiveness of the grassroots workers who are to be trained and through whom family planning motivational messages and methods are to be introduced. The Indian government, from time to time, has trained and utilized different groups of grassroots workers in its family planning promotional efforts. Anthropological field studies were conducted in two different regions in India to examine the potential and actual roles of two groups of grassroots workers--opinion leaders and traditional birth attendants--in the delivery of family planning services in the rural areas. These studies revealed that while the traditional birth attendants can be trained and utilized to a limited extent in promoting family planning efforts, especially to the eligible female clients, the role of the opinion leaders in such efforts is at best questionable. Based on these field studies, cultural and technical (including bureaucratic) problems in training and utilizing opinion leaders and traditional birth attendants are explored in detail. Modifications in the training program strategies are suggested to improve and expand the family planning delivery system in rural India.