Relative Curvature Measure for Heteroscedastic or Non Normal Nonlinear Regression

The Bates–Watts relative curvature measure can assess the validity of the linearized approximation in nonlinear regression models. However, it is developed based on an ordinary nonlinear regression in which the observation is assumed to be homoscedastically and normally distributed. In this article, we extend the original Bates–Watts relative curvature measure to one that can be applicable to nonlinear regression with heteroscedastic or non normal data, based on the transformation-both-sides (TBS) approach. In pharmacokinetic models, a diagnostic use of their measures is illustrated. By means of a simulation experiment, the performance of the relative curvature measure for the TBS approach is evaluated.     

Estimation of the covariance matrix with two-step monotone missing data

Abstract

We suggest shrinkage based technique for estimating covariance matrix in the high-dimensional normal model with missing data. Our approach is based on the monotone missing scheme assumption, meaning that missing values patterns occur completely at random. Our asymptotic framework allows the dimensionality p grow to infinity together with the sample size, N, and extends the methodology of Ledoit and Wolf (2004) Ledoit, O., Wolf, M. (2004). A well-conditioned estimator for large dimensional covariance matrices. J. Multivariate Anal. 88:365–411.[Crossref], [Web of Science ®] , [Google Scholar] to the case of two-step monotone missing data. Two new shrinkage-type estimators are derived and their dominance properties over the Ledoit and Wolf (2004) Ledoit, O., Wolf, M. (2004). A well-conditioned estimator for large dimensional covariance matrices. J. Multivariate Anal. 88:365–411.[Crossref], [Web of Science ®] , [Google Scholar] estimator are shown under the expected quadratic loss. We perform a simulation study and conclude that the proposed estimators are successful for a range of missing data scenarios.     

Bayesian sample‐size determination methods considering both worthwhileness and unpromisingness for exploratory two‐arm randomized clinical trials with binary endpoints

A randomized exploratory clinical trial comparing an experimental treatment with a control treatment on a binary endpoint is often conducted to make a go or no‐go decision. Such an exploratory trial needs to have an adequate sample size such that it will provide convincing evidence that the experimental treatment is either worthwhile or unpromising relative to the control treatment. In this paper, we propose three new sample‐size determination methods for an exploratory trial, which utilize the posterior probabilities calculated from predefined efficacy and inefficacy criteria leading to a declaration of the worthwhileness or unpromisingness of the experimental treatment. Simulation studies, including numerical investigation, showed that all three methods could declare the experimental treatment as worthwhile or unpromising with a high probability when the true response probability of the experimental treatment group is higher or lower, respectively, than that of the control treatment group.     

Decision-making under uncertainty: using MLMC for efficient estimation of EVPPI

Statistics and Computing - In this paper, we develop a very efficient approach to the Monte Carlo estimation of the expected value of partial perfect information (EVPPI) that measures the average...     

Teaching Perspectives on Cross-Cultural Psychology and Japanese Society

This article discusses educational aspects of cross-cultural psychology in relationship to Japanese society. After exploring the present status of cross-cultural psychology in Japan, the paper delineates the factual, theoretical, and methodological implications of cross-cultural psychology for the teaching of psychology in Japanese universities. It is argued that an area approach incorporating comparative research on Japanese society can add context, detail, historical perspective, new methodology, and interdisciplinary richness to classes otherwise relying on traditional journal articles and textbooks of cross-cultural psychology. Such an approach is deemed useful for cross-cultural psychology classes taking place both inside and outside Japan. The article concludes with an annotated bibliography of research on Japanese society.     

Social Workers' Use of the Internet and E-Mail to Help Clients in Virginia

A survey of a random sample of licensed social workers in Virginia showed 98.8% had Internet access in either their home or workplace. A comparison of this study with a study conducted in the early 2000s indicated more than 20% difference regarding e-mail communication with clients and Internet use for work-related research. Social workers who actually used the Internet and e-mail tended to expect a future increase in their use, in contrast with nonusers. Stepwise multiple logistic regression analyses found age and type of agency (private/for-profit) as factors negatively related to having Internet access in the workplace, age, and the reason “E-mail is not secure enough” as factors negatively related in the future e-mail communication with clients among current nonusers.     

Fetal movement frequency and the effect of associated perinatal factors: Multicenter study

Background

Decreased fetal movements are associated with adverse perinatal outcomes, including stillbirth. Delayed maternal visits to a health care provider after perceiving decreased fetal movements are frequently observed in stillbirths. Informing pregnant women of the normal range of fetal movement frequency is essential in their earlier visits in order to prevent stillbirth.

The Quality of Life in Japan

This study is part of a collaborative project examining the quality of life in Confucian societies in Asia. Our major findings suggest that, when our sixteen specific life domains are grouped into three life spheres, namely, material, post-material, and public, the Japanese people tend to be most satisfied with the post-material sphere of life and least satisfied with the public sphere of life such as the condition of environment and welfare system. In searching the direct, independent effects of demographics, lifestyles, value priorities, and domain assessments on the quality of life, none of the public life domain assessments shows a significant impact on the quality of life, while friendships and spiritual life in the post-material sphere of life are an important determinant. Equally notable is the finding that neither educational attainment nor household income contributes significantly to the experience of subjective well-being. Leading a global lifestyle also affects positively the quality of life. Finally, being married and satisfaction with marital life appear to be powerful and prevalent influence on the quality of life in Japan.

A necessary and sufficient condition for stable matching rules to be strategy-proof

We study one-to-one matching problems and analyze conditions on preference domains that admit the existence of stable and strategy-proof rules. In this context, when a preference domain is unrestricted, it is known that no stable rule is strategy-proof. We introduce the notion of the no-detour condition, and show that under this condition, there is a stable and group strategy-proof rule. In addition, we show that when the men’s preference domain is unrestricted, the no-detour condition is also a necessary condition for the existence of stable and strategy-proof rules. As a result, under the assumption that the men’s preference domain is unrestricted, the following three statements are equivalent: (i) a preference domain satisfies the no-detour condition, (ii) there is a stable and group strategy-proof rule, (iii) there is a stable and strategy-proof rule.     

Excessively delayed maternal reaction after their perception of decreased fetal movements in stillbirths: Population-based study in Japan

Background

Fetal movement is the most common method to evaluate fetal well-being. Furthermore, maternal perception of decreased fetal movements is associated with perinatal demise. Previously, we showed that perception of decreased fetal movements was the most common reason for mothers visiting the outpatient department among those who had stillbirths in our region. Further investigation of stillbirths with decreased fetal movements is essential to find a possible way of preventing stillbirth.