Reliability sampling plans for the Weibull distribution under Type II progressive censoring with binomial removals

This paper presents reliability sampling plans for the Weibull distribution under Type II progressive censoring with random removals (PCR), where the number of units removed at each failure time follows a binomial distribution. To construct the sampling plans, the sample size n and the acceptance constant k are determined based on asymptotic distribution theory. The resulting sampling plans are tabulated for selected specifications under the proposed censoring scheme. Furthermore, a Monte Carlo simulation is conducted to validate the true probability of acceptance for the designed sampling plans.     

Assessing Lund's critical values for testing for outliers in linear regression models

This note assesses Lund's critical bounds as approximations to the critical values of a size-a test for detecting single outlier in a multiple linear regression model. A Monte Carlo experiment shows that the empirical sizes are very close to the nominal sizes, and the regressors have little effect on the empirical sizes. Lund's tables are revised to higher accuracy.     

The research pendulum: multiple roles and responsibilities as a researcher

Qualitative research on sexual identities has highlighted the use of oral narratives to understand the lives of lesbians and gay men. Feminist ethnographers, sociologists and queer theorists have further posed methodological inquiries to the issues of insider/outsider, the possibilities of an erotic subject and the matter of representation. Using interview data with Hong Kong lesbians, this paper discusses a researcher's multiple positionalities and its effects on both the researched and the researcher. Being self-reflexive requires a researcher to test her or his own boundaries and to take up social responsibilities as the interpreter of texts. This paper calls for further dialogue between a researcher's subject positions, research processes and the final presentation of findings. doi:10.1300/J155v10n03_02.     

Deconvolution Estimation of Onset of Pregnancy with Replicate Observations

In general, the precise date of onset of pregnancy is unknown and may only be estimated from ultrasound biometric measurements of the embryo. We want to estimate the density of the random variables corresponding to the interval between last menstrual period and true onset of pregnancy. The observations correspond to the variables of interest up to an additive noise. We suggest an estimation procedure based on deconvolution. It requires the knowledge of the density of the noise which is not available. But we have at our disposal another specific sample with replicate observations for twin pregnancies. This allows both to estimate the noise density and to improve the deconvolution step. Convergence rates of the final estimator are studied and compared with other settings. Our estimator involves a cut‐off parameter for which we propose a cross‐validation type procedure. Lastly, we estimate the target density in spontaneous pregnancies with an estimation of the noise obtained from replicate observations in twin pregnancies.     

Impact of Community on Personal Well-Being in Urban China

ABSTRACT

As the work-unit system fell after economic reform in China, neighborhoods replaced work units as the primary provider of vital social services for the urban population and became a new social space for enhancing the quality of people's well-being. This study examined the neighborhood characteristics that influenced personal well-being of residents. Drawn by multistage sampling and administered by face-to-face interviews, the survey included a sample of 976 participants from 31 neighborhoods in urban Shanghai. Results indicate that neighboring behaviors enhanced subjective well-being of the young and middle-aged residents but had no impact on older people. Sense of community, on the other hand, was found to contribute to well-being of all age groups and was particularly strong among older people in more deprived neighborhoods. Findings inform development of community practice strategies for vitalizing community efficacy and fostering individual well-being in urban China. Recommendations for future research are made using the results of this study.     

Competitive Capabilities among Manufacturing Plants in Developing,Emerging, and Industrialized Countries: A Comparative Analysis

Competitive capabilities have been defined as a plant's actual performance relative to its competitors, with the most commonly investigated capabilities being quality, delivery, flexibility, and cost. However, most research in this realm has investigated capabilities within developed countries, and neglected the context of developing and emerging nations, which are increasingly becoming viable economic entities in global supply chains in their own right. The present study fills this gap and carries out a comparative analysis of competitive capabilities among plants in developing, emerging, and industrialized countries. Basing our arguments on the resource‐based view of the firm, we suggest that the influence of competitive capabilities on each other varies among plants in differentially industrialized regions. Specifically, we suggest that, on average, competitive capabilities tend to influence each other to a greater degree in plants in emerging and developing countries compared to industrialized countries. Along similar lines, we suggest that the influence of the four competitive capabilities on performance improvement is manifested more strongly among plants in emerging and developing countries than among plants in industrialized nations. We investigate these contentions with data from 1,211 plants in 21 countries. The results are particularly important for decision makers as they decide on the increasingly global location of their manufacturing operations or the configuration of their global supply chains.     

Income Inequality and Opioid Prescribing Rates: Exploring Rural/Urban Differences in Pathways via Residential Stability and Social Isolation

While opioid prescribing rates have drawn researchers' attention, little is known about the mechanisms through which income inequality affects opioid prescribing rates and even less focuses on whether there is a rural/urban difference in mediating pathways. Applying mediation analysis techniques to a unique ZIP code level dataset from several sources maintained by the Centers for Medicare and Medicaid Services, we explicitly examine two mechanisms through residential stability and social isolation by rural/urban status and find that (1) income inequality is not directly related to opioid prescribing rates, but it exerts its influence on opioid prescribing via poor residential stability and elevated social isolation; (2) social isolation accounts for two‐thirds of the mediating effect of income inequality on opioid prescribing rates among urban ZIP codes, but the proportion halves among rural ZIP codes; (3) residential stability plays a larger role in understanding how income inequality matters in rural than in urban ZIP codes; and (4) beneficiary characteristics only matter in urban ZIP codes. These findings offer nuanced insight into how income inequality affects opioid prescribing rates and suggests that the determinants of opioid prescribing rates vary by rural/urban status. Future research may benefit from identifying place‐specific factors for opioid prescribing rates.     

An Unfinished Reflexive Journey: Social Work Students' Reflection on their Placement Experiences

The fieldwork placement is recognized as one of the major componentsof social work education and a major determinant of its quality.A key aspect of the learning process in the fieldwork placementis the exposition of practice encounters to the students’critical reflection. Given the importance of the process of‘reflection’ or ‘reflective learning’,a qualitative study based on the reflective logs of social workstudents was conducted to explore the meaning of social workfield education and the learning experiences of social workstudents during their placement. The study findings revealedthat disturbing events experienced by students in their fieldworkwere a catalyst to their reflective process. Meanwhile, theirundue concern with knowledge and skills application within acircumscribed knowledge frame suggests the dominant influenceof scientism and competence-based practice in social work, inwhich learning outcomes and instrumental and technical reasoningare highly emphasized. Discovery of ‘self’ was alsothe major premise in the students’ reflection logs, inwhich a majority of them took their prevailing self-identityas a constant state to be verified in interaction with othersin the fieldwork placement. Reflexivity is manifested in askingfundamental questions about assumptions generated by formaland practice theories; it addresses the multiple interrelationsbetween power and knowledge, and acknowledges the inclusionof self in the process of knowledge creation in social workpractice. Its realization in social work education requiresthe social work educators’ reflexive examination of thedynamics that influence the construction of curriculum, whichin turn construct our prospective social workers.