寻找儒学者姜沆的足迹

姜沆(1567-1618),朝鲜李朝时代的儒学者,出生于全罗道灵光郡流峰里,1597年9月23日被日军囚禁.他著有《看羊录》痛斥日本侵略者的罪恶,姜沆以虏囚之身,用他的学识和精神给日本留下了伟大的文化之光.     

A convenient formula for sample size calculations in clinical trials with multiple co-primary continuous endpoints

The clinical efficacy of a new treatment may often be better evaluated by two or more co-primary endpoints. Recently, in pharmaceutical drug development, there has been increasing discussion regarding establishing statistically significant favorable results on more than one endpoint in comparisons between treatments, which is referred to as a problem of multiple co-primary endpoints. Several methods have been proposed for calculating the sample size required to design a trial with multiple co-primary correlated endpoints. However, because these methods require users to have considerable mathematical sophistication and knowledge of programming techniques, their application and spread may be restricted in practice. To improve the convenience of these methods, in this paper, we provide a useful formula with accompanying numerical tables for sample size calculations to design clinical trials with two treatments, where the efficacy of a new treatment is demonstrated on continuous co-primary endpoints. In addition, we provide some examples to illustrate the sample size calculations made using the formula. Using the formula and the tables, which can be read according to the patterns of correlations and effect size ratios expected in multiple co-primary endpoints, makes it convenient to evaluate the required sample size promptly.     

The biology of the voleClethrionomys rufocanus: A review

The biology of the gray-sided voleClethrionomys rufocanus in Hokkaido, concerning taxonomy, morphology, phylogeny, distribution, and natural history, is reviewed. Applied issues in forest management (damage, control and census) are also mentioned. AlthoughClethrionomys rufocanus of Hokkaido was originally identified as a distinct species,Evotomys (=nowClethrionomys) bedfordiae Thomas, 1905, current literature generally refers to the gray-sided vole of Hokkaido asClethrionomys rufocanus or asC. rufocanus bedfordiae (vernacular name, the Bedford’s red-backed vole). The gray-sided vole is the most common small mammal in Hokkaido. It inhabits open areas as well as forests, and mainly feeds on green plants. The gray-sided vole has a high reproductive potential; litter size: 4–7; gestation period: 18–19 days; maturation age: 30–60 days old. Although spring-born individuals usually attain sexual maturity in their summer/fall of birth, their maturation is sometimes suppressed under high densities. The breeding season is generally from April to October, but with some regional variation.Clethrionomys rufocanus has a rather specialized diet (folivorous), particularly during winter when it feeds on bamboo grass. Many predators specialize on the grey-sided vole in Hokkaido; even the red fox, which is a typical generalist predator, selectively feeds on this vole. Damage by voles’ eating bark used to be sever on forest plantations in Hokkaido. Censuses of small rodents have been carried out for management purpose since 1954.     

Spontaneous Facial Expressions Reveal New Action Units for the Sad Experiences

Facial expressions related to sadness are a universal signal of nonverbal communication. Although results of many psychology studies have shown that drooping of the lip corners, raising of the chin, and oblique eyebrow movements (a combination of inner brow raising and brow lowering) express sadness, no report has described a study elucidating facial expression characteristics under well-controlled circumstances with people actually experiencing the emotion of sadness itself. Therefore, spontaneous facial expressions associated with sadness remain unclear. We conducted this study to accumulate important findings related to spontaneous facial expressions of sadness. We recorded the spontaneous facial expressions of a group of participants as they experienced sadness during an emotion-elicitation task. This task required a participant to recall neutral and sad memories while listening to music. We subsequently conducted a detailed analysis of their sad and neutral expressions using the Facial Action Coding System. The prototypical facial expressions of sadness in earlier studies were not observed when people experienced sadness as an internal state under non-social circumstances. By contrast, they expressed tension around the mouth, which might function as a form of suppression. Furthermore, results show that parts of these facial actions are not only related to sad experiences but also to other emotional experiences such as disgust, fear, anger, and happiness. This study revealed the possibility that new facial expressions contribute to the experience of sadness as an internal state.     

Necessity of Transversality Conditions for Infinite Horizon Problems

This paper studies necessity of transversality conditions for the continuous time, reduced form model. By generalizing Benveniste and Scheinkman's (1982) “envelope” condition and Michel's (1990) version of the squeezing argument, we show a generalization of Michel's (1990, Theorem 1) necessity result that does not assume concavity. The generalization enables us to generalize Ekeland and Scheinkman's (1986) result as well as to establish a new result that does not require the objective functional to be finite. The new result implies that homogeneity of the return function alone is sufficient for the necessity of the most standard transversality condition. Our results are also applied to a nonstationary version of the one‐sector growth model. It is shown that bubbles never arise in an equilibrium asset pricing model with a nonlinear constraint.     

Relative Income and Happiness in Asia: Evidence from Nationwide Surveys in China, Japan, and Korea

This study attempts to examine relative income effects on perceived happiness in three major Asian countries—China, Japan, and Korea—in comparison with the United Sates, on the basis of largely comparable nationwide surveys in these countries. Consistent with the results from previous studies in Western countries, comparisons with an individual’s own income and average income of the reference group are significantly associated with the individual’s perceived happiness in Asia. The associations between relative income and happiness are stronger for individual income than family income in China, while the opposite is true in Japan and Korea. Even after controlling for the subjective assessment of family income or personal class identification within the society as a whole, income comparisons within the reference group matter for assessing happiness, especially when using family income for comparisons. Moreover, relative deprivation within the reference group, which is measured by the Yitzhaki index, is negatively related to happiness, providing more evidence for the validity of the relative income hypothesis.     

Sample size determination for clinical trials with co‐primary outcomes: exponential event times

Clinical trials with event‐time outcomes as co‐primary contrasts are common in many areas such as infectious disease, oncology, and cardiovascular disease. We discuss methods for calculating the sample size for randomized superiority clinical trials with two correlated time‐to‐event outcomes as co‐primary contrasts when the time‐to‐event outcomes are exponentially distributed. The approach is simple and easily applied in practice. Copyright © 2012 John Wiley & Sons, Ltd.     

On Testing Sample Selection Bias Under the Multicollinearity Problem

ABSTRACT

This paper reviews and extends the literature on the finite sample behavior of tests for sample selection bias. Monte Carlo results show that, when the “multicollinearity problem” identified by Nawata (1993 Nawata , K. ( 1993 ). A note on the estimation of models with sample-selection biases . Economics Letters 42 : 15 – 24 . [CSA] [CROSSREF] [Crossref], [Web of Science ®] , [Google Scholar]) is severe, (i) the t-test based on the Heckman–Greene variance estimator can be unreliable, (ii) the Likelihood Ratio test remains powerful, and (iii) nonnormality can be interpreted as severe sample selection bias by Maximum Likelihood methods, leading to negative Wald statistics. We also confirm previous findings (Leung and Yu, 1996 Leung , S. F. , Yu , S. ( 1996 ). On the choice between sample selection and two-part models . Journal of Econometrics 72 : 197 – 229 . [CSA] [CROSSREF] [Crossref], [Web of Science ®] , [Google Scholar]) that the standard regression-based t-test (Heckman, 1979 Heckman , J. J. ( 1979 ). Sample selection bias as a specification error . Econometrica 47 : 153 – 161 . [CSA] [Crossref], [Web of Science ®] , [Google Scholar]) and the asymptotically efficient Lagrange Multiplier test (Melino, 1982 Melino , A. ( 1982 ). Testing for sample selection bias . Review of Economic Studies 49 : 151 – 153 . [CSA] [Crossref], [Web of Science ®] , [Google Scholar]), are robust to nonnormality but have very little power.