TEACHING THE PRODUCTION/OPERATIONS MANAGEMENT CORE COURSE: INTEGRATING LOGISTICS PLANNING ACTIVITIES

This paper discusses the benefits of restructuring the introductory undergraduate production and operations management (pom) course to improve its pedagogical effectiveness and to better convey the importance of integrating logistics planning activities. The introduction of a dynamic integrative semester-long case study which involves students in applying pom concepts and tools through a simulation game is reported.     

Factors Associated with Adjustment to Marital Separation

Abstract

The dramatic increase in divorce in the United States over the past two decades has resulted in a need for closer examination of the factors associated with the adjustment to marital separation. This article reports a multivariate examination of health and social factors associated with post-separation adjustment In depth interviews were completed with 205 individuals, separated no longer than 26 months, about their marriage, its failure, and its aftermath. The study examines the role of social contact, health, economic stability, and dating behavior in the adjustment to marital separation. Multiple regression analysis is used to examine the independent and collective influences on adjustment, measured both by the Bradburn Affect Balance Scale and the Cantril Ladder technique. The analysis consistently demonstrated that economic stability, health status, and frequency of dating are significant predictors of post-separation adjustment. The implications of these findings are considered with special attention to some variations between sub-groups of the sample.     

The dynamics of hapū research relationships

Abstract

The Whakaki Lake Trust has a long history of being an active kaitiaki of Whakaki Lake and has developed a hapū-based restoration and enhancement programme at the Lake property. Part of this programme has involved working with a range of external agencies and researchers. Research relationships have become an important part of the restoration process to build the capability and capacity of hapū to execute activities associated with restoration. In addition, relationships have provided an opportunity to strengthen and expand the knowledge base that hapū can draw upon to inform ecological restoration and resource management decisions. Some of these relationships have been adversarial and a source of much frustration. As a consequence the Trust has developed very clear expectations and policy around working with others. My experience of developing a doctoral research project with Whakaki Lake Trust is used here to discuss hapū expectations of research and resultant academic dilemmas.     

Penalized Maximum Likelihood Estimator for Normal Mixtures

The estimation of the parameters of a mixture of Gaussian densities is considered, within the framework of maximum likelihood. Due to unboundedness of the likelihood function, the maximum likelihood estimator fails to exist. We adopt a solution to likelihood function degeneracy which consists in penalizing the likelihood function. The resulting penalized likelihood function is then bounded over the parameter space and the existence of the penalized maximum likelihood estimator is granted. As original contribution we provide asymptotic properties, and in particular a consistency proof, for the penalized maximum likelihood estimator. Numerical examples are provided in the finite data case, showing the performances of the penalized estimator compared to the standard one.     

中国古代慈善事业的发展特点

中国古代慈善事业在漫长的历史发展过程中不但逐渐形成了庞杂而丰富的思想体系,而且其慈善主体也实现了从最初单纯的国家慈善到以国家慈善为主、宗族慈善和宗教慈善为重要补充的多元化发展过程。另外,中国古代慈善事业的发展轨迹还明显具备与整个中国古代社会兴衰相表里的重要特点。     

The effects of strength training on memory in older adults

The authors examined whether resistance training has an effect on working memory span. Participants included 210 community-residing older adults with at least one disability from the Strong for Life program, a randomized controlled trial that examined the effects of home-based resistance exercise. Memory was assessed with the WAIS backward digit span at baseline and 3 and 6 months into the intervention. Although there were no differences between the experimental treatment and control groups in average levels of memory change, within the treatment group change in resistance level during the intervention was a significant predictor of memory change, controlling for age, education, sex, and disability level. The results suggest that strength training can benefit memory among older adults, especially when using higher resistance levels.     

A Pilot Randomized Trial of an Intervention to Enhance the Health-Promoting Effects of Older Adults’ Activity Portfolios: The Engaged4Life Program

The purpose of this study was to evaluate the feasibility and outcomes of the Engaged4Life program, an intervention to encourage inactive community-dwelling older adults to embed physical activity, cognitive activity, and social interaction into their everyday lives in contexts that are personally meaningful and natural for them. Fifteen participants were randomized to the intervention group (technology-assisted self-monitoring of daily activity via pedometers and daily tablet-based surveys; psychoeducation + goal-setting via a 3-hour workshop; and peer mentoring via phone 2×/week for 2.5 weeks) and 15 to the control (technology-assisted self-monitoring only). Recruitment was shown to be feasible and efficient, but not able to reach the target for men. Retention rate was 83% and participants manifested high adherence and engagement with the intervention. Though this pilot trial was not powered to demonstrate significant differences between groups, daily steps increased by 431 (11% increase) from baseline to Week 4 for the intervention (p < .05), but decreased by 458 for the control, for a net difference of 889 steps (p < .05). Findings were sustained at Week 8 (p < .01). In a future trial, difficulties in recruiting men, barriers due to the technology-intensive design, and the optimization of secondary outcome measures should be addressed.     

Estimating the Effects of Residential Mobility: A Methodological Note

This article reviews the methodological challenges of estimating a causal association between mobility and children's cognitive, social, emotional, and physical development. Utilizing a comprehensive set of empirical articles published in the past 25 years that employ quantitative methods, it describes the limitations of previous studies and the innovative ways that researchers have attempted to deal with them. The concept of mobility is inconsistently operationalized along four dimensions: school versus residential, distance, timing, and frequency. Imprecise operationalization conflates different forms of mobility, which have differential effects on development. Attempts to estimate a causal association between mobility and development suffer from three sources of bias: selection, contextual shifts, and contemporaneous instigating events. (a) Methods that account for unobserved differences between mobile and nonmobile children have consistently shown smaller or even positive effects of mobility. (b) Moving can have a positive or negative effect on children's ecological contexts in ways that are systematically correlated with child development. (c) Moves are frequently catalyzed by changes in family structure and employment. The article concludes with recommendations for future research. Researchers should continue to engage fixed- and random-effect, matching, and instrumental variable techniques, each of which makes the question of causality explicit.     

Can Johnson's Typology of Adult Partner Violence Apply to Teen Dating Violence?

The authors examined the applicability of Johnson's typology of adult intimate partner violence to female and male youth's reports of teen dating violence. A total of 5,647 youth from 10 schools participated in the survey, 3,745 of whom reported currently being in a dating relationship or having been in one during the prior year (52% female, 74% White). Using hierarchical cluster analysis to classify youth into high‐control versus no‐/low‐control violent experiences, the authors found that Johnson's typology provides a workable framework for examining the violent experiences of dating teens. For the one third of youth in violent relationships, the most common type of violence perpetrated was situational couple violence (86% for females and 80% for males), followed by intimate terrorism (7% for females and 11% for males). Six percent of females and males reported using violent resistance in their relationships, and 1% of females and 4% of males reported mutual violent control     

Non-parametric Quantile Regression with Censored Data

Abstract.  Censored regression models have received a great deal of attention in both the theoretical and applied statistics literature. Here, we consider a model in which the response variable is censored but not the covariates. We propose a new estimator of the conditional quantiles based on the local linear method, and give an algorithm for its numerical implementation. We study its asymptotic properties and evaluate its performance on simulated data sets.