Computing A-optimal and E-optimal designs for regression models via semidefinite programming

In semidefinite programming (SDP), we minimize a linear objective function subject to a linear matrix being positive semidefinite. A powerful program, SeDuMi, has been developed in MATLAB to solve SDP problems. In this article, we show in detail how to formulate A-optimal and E-optimal design problems as SDP problems and solve them by SeDuMi. This technique can be used to construct approximate A-optimal and E-optimal designs for all linear and nonlinear regression models with discrete design spaces. In addition, the results on discrete design spaces provide useful guidance for finding optimal designs on any continuous design space, and a convergence result is derived. Moreover, restrictions in the designs can be easily incorporated in the SDP problems and solved by SeDuMi. Several representative examples and one MATLAB program are given.     

A direct procedure for monitoring the coefficient of variation using a variable sample size scheme

A variable sample size (VSS) scheme directly monitoring the coefficient of variation (CV), instead of monitoring the transformed statistics, is proposed. Optimal chart parameters are computed based on two criteria: (i) minimizing the out-of-control ARL (ARL₁) and (ii) minimizing the out-of-control ASS (ASS₁). Then the performances are compared between these two criteria. The advantages of the proposed chart over the VSS chart based on the transformed statistics in the existing literature are: the former (i) provides an easier alternative as no transformation is involved and (ii) requires less number of observations to detect a shift when ASS₁ is minimized.     

Exponentially weighted moving average charts for correlated multivariate Poisson processes

In this article, we study exponentially weighted moving average (EWMA) control schemes to monitor the multivariate Poisson distribution with a general covariance structure, so that the practitioner can simultaneously monitor multiple correlated attribute processes more effectively. The statistical performance of the charts is assessed in terms of the run length properties and compared against other mainstream attribute control schemes. The application of the proposed methods to real-life and simulated datasets is demonstrated.     

Public Sociology on Twitter: a Space for Public Pedagogy?

Research has examined various elements of Twitter; however, no scholarship has explored how sociologists currently use the platform. This empirically driven paper explores how individuals that self-identify as sociologists on Twitter use the popular micro-blogging social media site. A total of 152,977 tweets from Twitter profiles of 130 sociologists were collected and examined using qualitative media analysis. The potential use of Twitter allows the sociologist to become both the generator and interlocutor of dialogue with publics. We frame our data analysis and discussion around the core theme of expertise - namely, the role that expertise plays in the use of Twitter by sociologists. Our findings indicate that when sociologists used Twitter as sociologists (i.e., drawing upon their stated research expertise) little direct engagement with publics occurred. Thus, while sociologists appear to be using Twitter as a space for public sociology, the use of this interactive platform is mostly limited to the generation of content, a finding consistent with Burawoy’s traditional form of public sociology. Suggestions for future research are noted.     

Fathers' Investments of Money and Time Across Residential Contexts

Fathers' roles in family life have changed dramatically over the past 50 years. In addition to ongoing breadwinning responsibilities, many fathers are now involved in direct caregiving and engagement with children. Yet there is considerable variation in what fathers do, especially depending on whether they live with or away from their child. In this article, the authors use data from the Fragile Families and Child Wellbeing Study (N = 3,869) to describe how fathers' economic capacities (money) and direct involvement with children (time) are associated over child ages 1 to 9 for resident versus nonresident fathers, net of confounding factors. They found suggestive evidence that money and time investments operate differently across residential contexts: Resident fathers experience a trade‐off between market work and time involved with children. In contrast, nonresident fathers' higher economic capacities are associated with more time involvement, underscoring the greater challenge for such fathers to remain actively involved.     

Grandparents' Education and Infant Health: Pathways Across Generations

Using data from the Fragile Families and Child Wellbeing survey linked to respondents' medical records (N = 2,870), this study examines the association between grandparents' education and birth outcomes and explores potential pathways underlying this relationship. Results show that having a grandfather with less than a high school education was associated with a 93 gram reduction in birth weight, a 59% increase in the odds of low birth weight, and a 136% increase in the odds of a neonatal health condition when compared with having a grandfather with a high school education or more. These associations were partially accounted for by mother's educational attainment and marital status as well as by prenatal history of depression, hypertension, and prenatal health behaviors, depending on the specific outcome. The findings from this study call for heightened attention to the multigenerational influences of educational attainment for infant health.     

“I Feel Like More of a Man”: A Mixed Methods Study of Masculinity,Sexual Performance,and Circumcision for HIV Prevention

Ethnographic studies from numerous societies have documented the central role of male circumcision in conferring masculinity and preparing boys for adult male sexuality. Despite this link between masculinity, sexuality, and circumcision, there has been little research on these dynamics among men who have been circumcised for HIV prevention. We employed a mixed methods approach with data collected from recently circumcised men in the Dominican Republic (DR) to explore this link. We analyzed survey data collected six to 12 months post-circumcision (N = 293) as well as in-depth interviews conducted with a subsample of those men (n = 30). We found that 42% of men felt more masculine post-circumcision. In multivariate analysis, feeling more masculine was associated with greater concern about being perceived as masculine (OR = 1.70, 95% CI: 1.25–2.32), feeling more potent erections post-circumcision (OR = 2.25, 95% CI: 1.26–4.03), and reporting increased ability to satisfy their partners post-circumcision (OR = 2.30, 95% CI: 1.11–4.77). In qualitative interviews, these factors were all related to masculine norms of sexually satisfying one’s partner, and men’s experiences of circumcision were shaped by social norms of masculinity. This study highlights that circumcision is not simply a biomedical intervention and that circumcision programs need to incorporate considerations of masculine norms and male sexuality into their programming.     

Discussing Global Issues Through Contemporary Art

Contemporary global issues can be examined through the lens of modern photographic art. In an effort to prepare global-ready graduates, this article explores the pressing problems of environmental degradation, urbanization, and homelessness through the work of three contemporary artists. Illustrative works, suggested approaches, and curriculum resources are provided.     

Sexually Experienced Adolescents’ Thoughts About Sexual Pleasure

Little research on adolescents has examined developmentally normative facets of sexuality that are not obviously linked to physical health. The purpose of this secondary data analysis was to qualitatively analyze adolescents’ thoughts about and experiences with sexual pleasure. The study sample consisted of 56 sexually experienced, ethnically diverse, predominantly female adolescents who were participating in a Web-based intervention to promote healthy sexual decision making. Comments on one message board, “Sexual Pleasure: Does It Matter to You?,” provided an opportunity to examine adolescents’ thoughts about and experiences with sexual pleasure, as well as their communication with partners about that topic. Adolescents’ comments demonstrated that they experience difficulties with pleasure in their sexual relationships. Adolescents generally believed that men are more likely than women to feel pleasure due to differences that include biology, understanding of one’s body, and control over partnered sexual behavior. Adolescents defined inequality of received pleasure differently and discussed contexts in which inequality may be acceptable. Adolescents expressed motivation to communicate with partners about sexual pleasure. However, their statements suggested they often lack the skills to do so. Future prevention and intervention programs should equip adolescents with skills to communicate with partners about sexual pleasure.     

“Men never cry”: Teaching Mormon Manhood in the Church of Jesus Christ of Latter-day Saints

We examine the ways Mormon leaders establish “what it means to be a man” for their followers. Based on content analysis of over 40 years of archival material, we analyze how Mormon leaders represent manhood as the ability to signify control over self and others as well as an inability to be controlled. Specifically, we demonstrate how these representations stress controlling the self, emotional and sexual expression, and others while emphasizing the development of self-reliance and independence from others’ control. We draw out implications for understanding (1) how religious leaders create ideal notions of manhood, (2) what the religious interpretations of secular constructions of manhood are, and (3) how these relate to the reproduction of gender inequalities.