Regularization through variable selection and conditional MLE with application to classification in high dimensions

It is often the case that high-dimensional data consist of only a few informative components. Standard statistical modeling and estimation in such a situation is prone to inaccuracies due to overfitting, unless regularization methods are practiced. In the context of classification, we propose a class of regularization methods through shrinkage estimators. The shrinkage is based on variable selection coupled with conditional maximum likelihood. Using Stein's unbiased estimator of the risk, we derive an estimator for the optimal shrinkage method within a certain class. A comparison of the optimal shrinkage methods in a classification context, with the optimal shrinkage method when estimating a mean vector under a squared loss, is given. The latter problem is extensively studied, but it seems that the results of those studies are not completely relevant for classification. We demonstrate and examine our method on simulated data and compare it to feature annealed independence rule and Fisher's rule.     

Impact of metabolic status on the association of serum vitamin D with hypogonadism and lower urinary tract symptoms/benign prostatic hyperplasia

Objective: The objective of this study is to investigate the impact of metabolic status on associations of serum vitamin D with hypogonadism and lower urinary tract symptoms (LUTS)/benign prostatic hyperplasia (BPH).

Patients and methods: A total of 612 men underwent physical examination, biochemical/hormonal blood testing, and transrectal prostate ultrasound. Moreover, the subjects filled out standard questionnaires for identification and grading of LUTS and hypogonadism symptoms. Parameters were statistically compared with independent t-tests and correlation analyses.

Results: Vitamin D levels positively correlated with total testosterone (TT) but not with prostate volume or International Prostate Symptom Score (IPSS). Patients with metabolic syndrome had significantly lower vitamin D levels, which were not correlated with TT, prostate volume, or IPSS. However, vitamin D was positively correlated with TT, and negatively correlated with prostate volume and quality-of-life IPSS in subjects without metabolic syndrome.

Conclusion: The clinical usefulness of vitamin D for treatment of hypogonadism or LUTS/BPH varies according to metabolic status.     

Extended scaled prediction variance optimality for modified central composite design

Robust parameter designs (RPDs) enable the experimenter to discover how to modify the design of the product to minimize the effect due to variation from noise sources. The aim of this article is to show how this amount of work can be reduced under modified central composite design (MCCD). We propose a measure of extended scaled prediction variance (ESPV) for evaluation of RPDs on MCCD. Using these measures, we show that we can check the error or bias associated with estimating the model parameters and suggest the values of α recommended for MCCS under minimum ESPV.     

Community-Based Services and Depression from Person-Environment Fit Perspective: Focusing on Functional Impairments and Living Alone

ABSTRACT

Guided by the Person-Environment Fit perspective, we investigated the extent to which personal and environmental factors influence depression among community-dwelling adults. The data came from the special section about community-based service utilization in the 2012 Health and Retirement Study (N=1,710). Although community-based service was not significantly associated with depression after controlling for covariates, respondents with functional limitations and living alone were less likely to be depressed when using community-based services. This study demonstrates the different associations between community-based services and depression depending on personal needs. It discusses the importance of community-based services for aging-in-place policy, particularly among vulnerable populations.     

The gendered contours of North Korean Migration: sexualized bodies and the violence of phenotypical normalization in South Korea

This article examines the gendered and sexualized contours of North Korean experiences in South Korea at a time when nearly 70% of the North Korean emigrants are women. South Korean television shows – e.g. reality programs – and marriage matchmaking organizations seek to portray North Korean women in a ‘positive’ way to the South Korean public, although, as this article will illustrate, these representations are of a very particular, sexualized kind. These representations are sometimes negative, and there is stigma attached to North Korean women, in which South Koreans assume, for example, that they are victims of human trafficking or that they have had relations with Chinese men during their migration. Furthermore, poor nutrition and other forms of structural violence in North Korea have molded North Korean bodies; there are often physical disparities between North and South Koreans. In South Korean society where short height is viewed as undesirable and where idealized, surgical notions of beauty dominate, the violence of gendered phenotypical normalization mark North Korean bodies as smaller, foreign, and strange. Based on ethnographic research in South Korea, this article argues that these gendered contours of North Korean migration amount to a different sort of structural violence in South Korea.     

Family Roles as Moderators of the Relationship Between Schedule Flexibility and Stress

Employer initiatives that address the spillover of work strain onto family life include flexible work schedules. This study explored the mediating role of negative work–family spillover in the relationship between schedule flexibility and employee stress and the moderating roles of gender, family workload, and single‐parent status. Data were drawn from the 2008 National Study of the Changing Workforce, a nationally representative sample of working adults (N = 2,769). The results indicated that schedule flexibility was associated with less employee stress and that these associations were mediated by perceptions of negative work–family spillover. This study found the moderating relationships of gender, family workload, and single parenting in the relationships between schedule flexibility and negative work–family spillover and stress. Schedule flexibility had stronger relationships in reducing negative work–family spillover and stress among women, single parents, and employees with heavier family workloads. The findings provide empirical support for intervention efforts involving schedule flexibility to reduce workplace stress among employees with family responsibilities.     

Influence of Temporal Distance on the Perceived Importance of Career‐Related Self‐Efficacy and Outcome Expectations

Because all career choices are about future actions, time is an important contextual variable in social cognitive career choice ( Hesketh, 2000 ). However, there is a dearth of research examining the effect of time. The authors examined how temporal distance to career entry influences the perceived importance of self‐efficacy and outcome expectations concerning a career pursuit. They also examined the moderating effects of perceived support and barriers, as well as country. The participants were college students in the United States (n= 180) and in South Korea (n= 215). The results of hierarchical regression analyses did not show main effects of time, but a 3‐way interaction indicated the complex interplay of time and other contextual variables. Implications for career counseling and future research are discussed.     

Using the Constructs Multifinality,Work Hope,and Possible Selves With Urban Minority Youth

This article describes and highlights the potential contributions that the constructs multifinality, work hope, and possible selves make for designing career counseling interventions and for better understanding possible career‐related factors associated with academic engagement and achievement among urban minority youth. Multifinality may serve as a superordinate orientation because it conceptualizes development as discontinuous and relatively plastic, allowing for youth deemed at risk to follow more hopeful pathways. Work hope and possible selves emphasize the utility of providing urban minority youth with space to answer questions related to what they might achieve and do in the future and who they might become. Together, multifinality, work hope, and possible selves provide a hopeful conceptual framework for career researchers and practitioners.     

“Who Are You?”: The Making of Korean “Illegal Entrants” in Occupied Japan 1945–1952

Recent progress in the study of migration history in Japan has cast new light on the influx of Koreans to Japan just after the end of the Second World War in August 1945. Both the Japanese Government and the Supreme Commander for the Allied Powers called this migration illegal entry or smuggling, and tried to suppress it., One important question remains to be solved about this migration; namely; how was it prohibited? Before the Immigration Control Act (1951) was enshrined, and at a time when Koreans in Japan still held Japanese citizenship, how were the authorities able to regard Korean migration to Japan illegal? How did this migration became a political and social problem? Focusing on the legislation process and performance of the law, this article attempts to answer these questions. Politics, legislation, and social interaction all contributed to making the ethnic and legal category of Korean in postwar Japan.