Estimation of the population mean and median using truncation-based ranked set samples

In this paper, a new sampling method is suggested, namely truncation-based ranked set samples (TBRSS) for estimating the population mean and median. The suggested method is compared with the simple random sampling (SRS), ranked set sampling (RSS), extreme ranked set sampling (ERSS) and median-ranked set sampling (MRSS) methods. It is shown that for estimating the population mean when the underlying distribution is symmetric, TBRSS estimator is unbiased and it is more efficient than the SRS estimator based on the same number of measured units. For asymmetric distributions considered in this study, TBRSS estimator is more efficient than the SRS for all considered distributions except for exponential distribution when the selection coefficient gets large. When compared with ERSS and MRSS methods, TBRSS performs well with respect to ERSS for all considered distributions except for U(0, 1) distribution, while TBRSS efficiency is higher than that of MRSS for U(0, 1) distribution. For estimating the population median, the TBRSS estimators have higher efficiencies when compared with SRS and ERSS. A real data set is used to illustrate the suggested method.     

Best linear unbiased and invariant estimation in location-scale families based on double-ranked set sampling

Abstract

In this article, we propose the best linear unbiased estimators (BLUEs) and best linear invariant estimators (BLIEs) for the unknown parameters of location-scale family of distributions based on double-ranked set sampling (DRSS) using perfect and imperfect rankings. These estimators are then compared with the BLUEs and BLIEs based on ranked set sampling (RSS). It is shown that under perfect ranking, the proposed estimators are uniformly better than the BLUEs and BLIEs obtained via RSS. We also propose the best linear unbiased quantile (BLUQ) and the best linear invariant quantile (BLIQ) estimators for normal distribution under DRSS. It is observed that the proposed quantile estimators are more efficient than the BLUQ and BLIQ estimators based on RSS for both perfect and imperfect orderings.     

On the estimation of the most probable number in a serial dilution experiment

The purpose of this paper is to present some alternative estimates for the 'most probable number' of bacteria in a serial dilution experiment. These estimates are directed to be less biased than the ordinary maximum likelihood estimate. A numerical example illustrates the extent to which the variance and the mean square error of these estimates are generally less than those corresponding to the maximum likelihood estimate.     

Humerical. Results concerning the mle of an exponential parameter used in life testing

It was previously shown that the maximum likelihood estimator 0 of the scale parameter of the exponential distribution is asymptotically normal for type-I censoring. Applicability of the asymptotic normality results for finite samples is studied here by computer simulation for several different normalizing factors and for various levels of censoring. The use of the asymptotic results in statistical problems is illustrated by an example     

Social work in a conflict context: Challenges facing social workers with indigenous inhabitants of unrecognised villages in Israel

This qualitative study presents the experiences of social workers whose clients are the inhabitants of unrecognised Bedouin Arab villages in Israel. It used in‐depth, semi‐structured interviews with 25 participants, recruited by the snowball method. These social workers reported that they are caught between their personal and professional values, on the one hand, and employer regulations, government policy and government law, on the other – which greatly limits their ability to fulfil their professional role. The social workers also comment that they are working in a ‘grey area’ in which the government’s policy is unclear. This adds another layer of complexity to their work and reveals the differential implementation of critical social work principles by social workers with different cultural identities.     

The home situation and the homosexual

This article is concerned with the home situation of the homosexual, as a part of the process which develops homosexuality. An exploratory study was conducted in San Francisco on a sample of the homosexual population. Three hypotheses were examined: there is a positive relationship between the incidence of homosexuality and the unhappy childhood of the homosexual at home; there is a positive relationship between the confusion in sexual role‐playing in early ages, and homosexual behavior; and there is a positive relationship between the presence of homosexual family members and the development of new homosexuals. The data were collected in recorded interviews. Fingings tended to suport the first hypothesis, but did not support the second and third hypothesis.     

Investigating the self-care practices of social work faculty: an exploratory study

Being a social work faculty member in academe can be challenging. Evidence suggests that faculty members, in general, experience high levels of stress and occupational burnout. Furthermore, harassment, bullying, and mobbing are commonplace. These problematic circumstances may be compounded for females, junior faculty, and under-represented (e.g. peoples of color) faculty groups. Engaging in adroit self-care practices is one way to assuage these problematic employment circumstances. Yet, there is a dearth in the literature that examines self-care practices among social work educators. This exploratory study examined the self-care practices of social work faculty (N = 124) at Council on Social Work Education accredited institutions in one southeastern state in the United States. Overall, data suggest that social work faculty do engage in adequate self-care practices, when compared to studies of general social work practitioners. Data also suggest differences in self-care by academic rank and professional licensing. After a brief review of literature, this paper will explicate results and identify salient discussion points and implications for social work education. This is the first paper known to the authors to explore self-care among social work faculty.     

Riotous Citizens: Ethnic Conflict in Multicultural Britain

Forest struggles and movements in India were a part of the rich tradition of anti-colonial struggle. In North Bengal, the recorded history of forest movements dates back to the 1960s and the movements themselves have been continuous ever since. However, despite the sincere efforts of those movements the livelihood opportunities of the forest dwellers worsened daily. The 1972 Wildlife Act together with the 1980 Forest Conservation Act strengthened further the oppressive structure of the forest bureaucracy. After the introduction of the Joint Forest Management Programme in the 1990s backed by the 1988 Forest Policy in India, it was expected that the forest dwellers would become more empowered economically and socially in lieu of their participation in the forest protection activities. But this failed miserably in the region and in 2000, against such a backdrop, a movement was started to demand land and livelihood rights for the forest dwellers. Following the Notification of the Forest Rights Act (2006) the movement has gained a new momentum while continuing its struggle against the biased implementation of the Act. This article presents a brief account of the movement in order to assess its significance and changing focuses over the years.     

A New Discordancy Test in Circular Data Using Spacings Theory

In this article, we propose a new test of discordancy based on spacing theory in circular data. The test should provide a good alternative to existing tests of discordancy for detecting single or well-separated multiple outliers. On top of that, the new method can be generalized to identify a patch of outliers in data. The percentage points are calculated and the performance is examined. We first investigate the performance of the test for detecting a single outlier and show that the new test performs well compared to other known tests. We then show that the generalized test works well in detecting a patch of outliers in the data. As an illustration, a practical example based on an eye dataset obtained from a glaucoma clinic at the University of Malaya Medical Center, Malaysia is presented.     

The Correlated Bivariate Noncentral F Distribution and Its Application

This article proposes the singly and doubly correlated bivariate noncentral F (BNCF) distributions. The probability density function (pdf) and the cumulative distribution function (cdf) of the distributions are derived for arbitrary values of the parameters. The pdf and cdf of the distributions for different arbitrary values of the parameters are computed, and their graphs are plotted by writing and implementing new R codes. An application of the correlated BNCF distribution is illustrated in the computations of the power function of the pre-test test for the multivariate simple regression model (MSRM).