Investigating a Longitudinal Trajectory of Child Obesity and Its Association with Child Maltreatment in South Korea

This study investigated the association between child maltreatment and body mass index (BMI) using data from four waves (wave 2 in 2011 through 5 in 2014) of the Korean Children & Youth Panel Survey collected by the South Korean National Youth Policy Institute. We employed a latent growth curve modeling approach to estimate an unobserved latent trajectory and to test the longitudinal effects of child abuse and neglect on BMI. Our results indicate that child abuse is significantly associated with BMI and children who report higher levels of abuse tend to have higher rates of increase in their BMI. This study addresses a gap in the literature by demonstrating that a parent's maltreatment of their child has a long‐term effect on the rate of change in their BMI over time.     

Analysis of inaccurate data with mixture measurement error models

Measurement error, the difference between a measured (observed) value of quantity and its true value, is perceived as a possible source of estimation bias in many surveys. To correct for such bias, a validation sample can be used in addition to the original sample for adjustment of measurement error. Depending on the type of validation sample, we can either use the internal calibration approach or the external calibration approach. Motivated by Korean Longitudinal Study of Aging (KLoSA), we propose a novel application of fractional imputation to correct for measurement error in the analysis of survey data. The proposed method is to create imputed values of the unobserved true variables, which are mis-measured in the main study, by using validation subsample. Furthermore, the proposed method can be directly applicable when the measurement error model is a mixture distribution. Variance estimation using Taylor linearization is developed. Results from a limited simulation study are also presented.     

Graphical evaluation of robust parameter designs based on extended scaled prediction variance and extended spherical average prediction variance

For any response surface design, there are locations in the design region where responses are estimated well and locations where estimation is relatively poor. Consequently, graphical evaluation—such as variance dispersion graphs and the fraction of design space—is used as an alternative to a single-valued criterion. Such plots are used to investigate and compare the prediction capabilities of certain response surface designs currently available to the researcher. In this article, we propose the extended scaled prediction variance and extended spherical average prediction variance as prediction methods. We also illustrate how graphical methods can be employed to evaluate robust parameter designs.     

Simple Transformation Techniques for Improved Non-parametric Regression

We propose and investigate two new methods for achieving less bias in non- parametric regression. We show that the new methods have bias of order h ⁴, where h is a smoothing parameter, in contrast to the basic kernel estimator's order h ². The methods are conceptually very simple. At the first stage, perform an ordinary non-parametric regression on { x_i , Y_i } to obtain m^ ( x_i ) (we use local linear fitting). In the first method, at the second stage, repeat the non-parametric regression but on the transformed dataset { m^ ( x_i , Y_i )}, taking the estimator at x to be this second stage estimator at m^ ( x ). In the second, and more appealing, method, again perform non-parametric regression on { m^ ( x_i , Y_i )}, but this time make the kernel weights depend on the original x scale rather than using the m^ ( x ) scale. We concentrate more of our effort in this paper on the latter because of its advantages over the former. Our emphasis is largely theoretical, but we also show that the latter method has practical potential through some simulated examples.     

Development of r,T hybrid sampling plans for exponential lifetime distributions

SUMMARY In the original hybrid reliability acceptance sampling plan RASP developed by Epstein for the exponential lifetime distribution, the sample size n and the number of failures r to be observed are determined given the truncation time T . However, these plans cannot be used when test items are expensive and or limited in number. Therefore, one wishes to have a plan in which n is given. In this paper, we develop hybrid RASPs in which r and T are determined, given n. These plans are tabulated for various combinations of parameter values, so that one may easily determine an appropriate plan.     

To market, to market: the changing face of grocery retailing

Over the past few years, grocery retailing has undergone a tremendous transformation which was driven mainly by changing consumer characteristics. In order to accommodate these changes, the industry has responded in three ways. The most important of these is the introduction of new technology, particularly efficient consumer response (ECR). The second change has to do with innovations in product and/or service offerings. The final transformation is the organisational restructuring and the increasing number of mergers and acquisitions in the industry at both the manufacturer and retailer levels. The implications of these transformations on the marketing mix, productivity and manufacturer-retailer relationships are discussed.     

BONDING AND BRIDGING ACTIVITIES OF U.S. PENTECOSTALS

A growing body of literature weighs the influence of religion on civic life. Largely missing from prior analysis is Pentecostals. With novel religious beliefs and practices, Pentecostals might be expected to focus more on in-group bonding activities than out-group bridging activities. We test this expectation using national data from the 2005 Baylor Religion Survey. We contrast three measures of Pentecostalism: denominational affiliation, speaking in tongues at a place of worship, and self-described Pentecostal/charismatic identity. Results affirm high rates of bonding activity (church attendance and other congregation activity) for contemporary Pentecostals. Results for Pentecostal bridging are more complicated. People in Pentecostal denominations and those who speak in tongues participate less in community organizations and politics. However, this is more a function of social class and general conservatism than religious culture or sense of identity. Comparable to other conservative Protestants, the vitality of Pentecostal groups seems no impediment to democratic society.     

Droit aux congés et conciliation entre travail et vie familiale dans les pays développés: pourquoi les travailleurs des Etats‐Unis sont perdants

A partir d'un indice synthétique des dispositions réglementaires sur les congés annuels et familiaux en Europe occidentale, aux Etats‐Unis, au Canada, en Australie, au Japon et en Corée, les auteurs classent ces pays quant au soutien à l'équilibre entre travail et famille. Les Etats‐Unis arrivent derniers: les employeurs ne sont pas tenus d'accorder des congés annuels, et les salariés ne peuvent prendre plus de douze semaines de congés par an pour raisons familiales. Ces normes comparativement basses s'expliqueraient par une conception fondée sur le libre marché et un postulat d'égalité de rapport de forces entre employeur et salarié. Vision qui n'est pleinement partagée par aucune des autres démocraties examinées.