On the distributions of multivariate sample skewness

In this paper, we consider the multivariate normality test based on measure of multivariate sample skewness defined by Srivastava (1984). Srivastava derived asymptotic expectation up to the order N⁻¹ for the multivariate sample skewness and approximate χ²${\chi }^2$ test statistic, where N   is sample size. Under normality, we derive another expectation and variance for Srivastava's multivariate sample skewness in order to obtain a better test statistic. From this result, improved approximate χ²${\chi }^2$ test statistic using the multivariate sample skewness is also given for assessing multivariate normality. Finally, the numerical result by Monte Carlo simulation is shown in order to evaluate accuracy of the obtained expectation, variance and improved approximate χ²${\chi }^2$ test statistic. Furthermore, upper and lower percentiles of χ²${\chi }^2$ test statistic derived in this paper are compared with those of χ²${\chi }^2$ test statistic derived by Mardia (1974) which is used multivariate sample skewness defined by Mardia (1970).     

A pragmatic dose‐finding approach using short‐term surrogate efficacy outcomes to evaluate binary efficacy and toxicity outcomes in phase I cancer clinical trials

There is a growing need for study designs that can evaluate efficacy and toxicity outcomes simultaneously in phase I or phase I/II cancer clinical trials. Many dose‐finding approaches have been proposed; however, most of these approaches assume binary efficacy and toxicity outcomes, such as dose‐limiting toxicity (DLT), and objective responses. DLTs are often defined for short time periods. In contrast, objective responses are often defined for longer periods because of practical limitations on confirmation and the criteria used to define ‘confirmation’. This means that studies have to be carried out for unacceptably long periods of time. Previous studies have not proposed a satisfactory solution to this specific problem. Furthermore, this problem may be a barrier for practitioners who want to implement notable previous dose‐finding approaches. To cope with this problem, we propose an approach using unconfirmed early responses as the surrogate efficacy outcome for the confirmed outcome. Because it is reasonable to expect moderate positive correlation between the two outcomes and the method replaces the surrogate outcome with the confirmed outcome once it becomes available, the proposed approach can reduce irrelevant dose selection and accumulation of bias. Moreover, it is also expected that it can significantly shorten study duration. Using simulation studies, we demonstrate the positive utility of the proposed approach and provide three variations of it, all of which can be easily implemented with modified likelihood functions and outcome variable definitions. Copyright © 2013 John Wiley & Sons, Ltd.     

Augmenting a Submodular and Posi-modular Set Function by a Multigraph

Given a finite set V and a set function , we consider the problem of constructing an undirected multigraph G = (V,E) such that the cut function together has value at least 2 for all non-empty and proper subsets of V. If f is intersecting submodular and posi-modular, and satisfies the tripartite inequality, then we show that such a multigraph G with the minimum number of edges can be found in time, where is the time to compute the value of f(X) for a subset .     

Estimating the Lyapunov exponent from chaotic time series with dynamic noise

In this paper, we propose an estimator of the Lyapunov exponent of the skeleton for chaotic time series with dynamic noise and prove the consistency of the estimator under some assumptions.     

Infants' preference for speech is stable across the first year of life: Meta-analytic evidence

Previous work suggested that humans' sophisticated speech perception abilities stem from an early capacity to pay attention to speech in the auditory environment. What are the roots of this early preference? We assess the extent to which it is due to it being a vocal sound, a natural sound, and a familiar sound through a meta-analytic approach, classifying experiments as a function of whether they used native or foreign speech and whether the competitor, against which preference is tested, was vocal or non-vocal, natural or artificial. We also tested for the effect of age. Synthesizing data from 791 infants across 39 experiments, we found a medium effect size, confirming at the scale of the literature that infants reliably prefer speech over other sounds. This preference was not significantly moderated by the language used, vocal quality, or naturalness of the competitor, nor by infant age. The current body of evidence appears most compatible with the hypothesis that speech is preferred consistently as such and not just due to its vocal, natural, or familiar nature. We discuss limitations of the extant body of work on speech preference, including evidence consistent with a publication bias and low representation of certain stimuli types and ages.     

Cross-Cultural Psychology in Japan

This article portrays the situation of cross-cultural psychology in Japan, including historical background, institutional aspects, and research findings by Japanese investigators. Reflecting the internationalization of Japanese society, cultural influences on human behavior have recently drawn the attention of Japanese psychologists, and the number of researchers engaged in cross-cultural investigations is steadily increasing. A review of articles in current Japanese journals suggests that most cross-cultural studies belong to the areas of social, educational, and developmental psychology where they increasingly focus on specific themes and hypotheses. Although cross-cultural psychologists interact in each research area, cross-cultural findings have only rarely been discussed or integrated on the common plane of cross-cultural psychology. In part, this is true because no association of cross-cultural psychology exists in Japan. The authors emphasize the importance of a systematic approach to response styles which influence research findings and the fruitfulness of comparing Japanese findings to those obtained in other non-Western societies.     

A study on the relationship between commitment of club activity and vocational readiness among university students

The purpose of this study was to clarify the relationship between commitment of club activities and the vocational readiness among juniors at university. In this study, organizational commitment questionnaire (Mowday, 1979) and vocational readiness scale (Wakabayashi, Goto, and Shinkai, 1983) were tested with 178 (120 men, 58 women) juniors at one physical education university in the metropolitan area. According to correlation analysis, the relation between commitment of club activities and the vocational readiness was positive significant correlation (r = .303, p < .01). Moreover, we executed t-test. As the combined results, this study provided the following three conclusions; 1) Vocational readiness score of students who belonged to the club were higher than that of other students. 2) Vocational readiness score of students who were committed to club activities were higher than that of students with low commitment to club activities. 3) Students who were committed to club activities tended to increase the score of vocational readiness. It was not able to be declared that there were positive influences of the club activities in university education from the viewpoint of vocational readiness acquisition. Therefore, it is necessary to consider what the club activities should be from the viewpoint of university student's career education.     

A study on the influence of headphones in auditory perceptual function

The focus of this study is a human's ability to make full use of listening and hearing. This ability consists of dividing auditory information into a signal and a noise. To evaluate the risk of using headphones, the study investigated the auditory perception when a warning sound is given in the presence of environmental noise.     

Avowed Happiness in Confucian Asia: Ascertaining its Distribution,Patterns, and Sources

This study reviewed three philosophical accounts of happiness, and then tested those accounts with the Asiabarometer surveys conducted in six Confucian societies during the summer of 2006. Statistical analyses of these surveys reveal that East Asians tend to experience happiness to a greater extent when they experience enjoyment together with achievement and/or satisfaction. The preponderance of such multi-dimensional conceptions in all those societies poses a direct challenge to a single dimensional account of happiness in the West. The analyses also reveal that positive assessments of interpersonal relationships matter more than the amount of knowledge or wealth in living a happy life in Confucian societies.

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A simple test for the treatment effect in clinical trials with a sequential parallel comparison design and negative binomial outcomes

In placebo‐controlled, double‐blinded, randomized clinical trials, the presence of placebo responders reduces the effect size for comparison of the active drug group with the placebo group. An attempt to resolve this problem is to use the sequential parallel comparison design (SPCD). Although there are SPCDs with dichotomous or continuous outcomes, an SPCD with negative binomial outcomes—with which investigators deal eg, in clinical trials involving multiple sclerosis, where the investigators are still concerned about the presence of placebo responders—has not yet been discussed. In this article, we propose a simple test for the treatment effect in clinical trials with an SPCD and negative binomial outcomes. Through simulations, we show that the analysis method achieves the nominal type I error rate and power, whereas the sample size calculation provides the sample size with adequate power accuracy.