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51.
随着两岸关系和平发展的持续推进,这项战略已经产生了强大的溢出效应。影响所及,两岸关系结构、台湾民众对两岸关系的认知结构以及台湾岛内话语结构等都发生了根本性变化,这种局面对岛内政党政治的基本生态和未来发展趋势产生了较大影响,两个主要政党都针对环境的变化进行了一定的调整,以求适应台海局势的结构性变化,谋求未来更多的发展空间。  相似文献   
52.
A simulation study of the binomial-logit model with correlated random effects is carried out based on the generalized linear mixed model (GLMM) methodology. Simulated data with various numbers of regression parameters and different values of the variance component are considered. The performance of approximate maximum likelihood (ML) and residual maximum likelihood (REML) estimators is evaluated. For a range of true parameter values, we report the average biases of estimators, the standard error of the average bias and the standard error of estimates over the simulations. In general, in terms of bias, the two methods do not show significant differences in estimating regression parameters. The REML estimation method is slightly better in reducing the bias of variance component estimates.  相似文献   
53.
In this work, we discuss the class of bilinear GARCH (BL-GARCH) models that are capable of capturing simultaneously two key properties of non-linear time series: volatility clustering and leverage effects. It has often been observed that the marginal distributions of such time series have heavy tails; thus we examine the BL-GARCH model in a general setting under some non-normal distributions. We investigate some probabilistic properties of this model and we conduct a Monte Carlo experiment to evaluate the small-sample performance of the maximum likelihood estimation (MLE) methodology for various models. Finally, within-sample estimation properties were studied using S&P 500 daily returns, when the features of interest manifest as volatility clustering and leverage effects. The main results suggest that the Student-t BL-GARCH seems highly appropriate to describe the S&P 500 daily returns.  相似文献   
54.
In analyzing data from unreplicated factorial designs, the half-normal probability plot is commonly used to screen for the ‘vital few’ effects. Recently, many formal methods have been proposed to overcome the subjectivity of this plot. Lawson (1998) (hereafter denoted as LGB) suggested a hybrid method based on the half-normal probability plot, which is a blend of Lenth (1989) and Loh (1992) method. The method consists of fitting a simple least squares line to the inliers, which are determined by the Lenth method. The effects exceeding the prediction limits based on the fitted line are candidates for the vital few effects. To improve the accuracy of partitioning the effects into inliers and outliers, we propose a modified LGB method (hereafter denoted as the Mod_LGB method), in which more outliers can be classified by using both the Carling’s modification of the box plot (Carling, 2000) and Lenth method. If no outlier exists or there is a wide range in the inliers as determined by the Lenth method, more outliers can be found by the Carling method. A simulation study is conducted in unreplicated 24 designs with the number of active effects ranging from 1 to 6 to compare the efficiency of the Lenth method, original LGB methods, and the proposed modified version of the LGB method.  相似文献   
55.
Despite the renewed interest in youth volunteering in recent years, there remain major gaps in our knowledge of its consequences. Drawing data from the National Longitudinal Study of Adolescent to Adult Health, we examine the long-term effects of youth volunteering on the civic and personal aspects of volunteers’ lives. Our results suggest that youth volunteering has a positive return on adult volunteering only when it is voluntary, and that net of contextual factors neither voluntary nor involuntary youth service has a significant effect on adult voting. Regarding personal outcomes, our findings indicate that the psychological benefits of youth volunteering accrue only to voluntary participants, whereas both voluntary and involuntary youth service are positively associated with educational attainment and earnings in young adulthood. Taken together, these results lend support to the case for youth volunteer programs, though the civic benefits of these programs appear to be less dramatic than generally suggested.  相似文献   
56.
Higher educated people tend to be more accepting of homosexuality than lower educated people. This has inspired claims that education leads to a higher acceptance of homosexuality. Alternatively, the association between education and acceptance of homosexuality could be confounded by (un)observed family background and stable individual characteristics. This study investigated the association between education and acceptance of homosexuality and the role of potential confounders in a unique longitudinal sample of British siblings. Multilevel and fixed effects analyses show that both perspectives apply. A large part of the association between education and acceptance of homosexuality could be attributed to family background and observed individual characteristics (one third), as well as unobserved individual characteristics (an additional third), but the positive association remains. Findings are discussed in light of existing explanations regarding the effect of education on the acceptance of homosexuality.  相似文献   
57.
We investigate the asymptotic behaviour of binned kernel density estimators for dependent and locally non-stationary random fields converging to stationary random fields. We focus on the study of the bias and the asymptotic normality of the estimators. A simulation experiment conducted shows that both the kernel density estimator and the binned kernel density estimator have the same behavior and both estimate accurately the true density when the number of fields increases. We apply our results to the 2002 incidence rates of tuberculosis in the departments of France.  相似文献   
58.
Sample selection and attrition are inherent in a range of treatment evaluation problems such as the estimation of the returns to schooling or training. Conventional estimators tackling selection bias typically rely on restrictive functional form assumptions that are unlikely to hold in reality. This paper shows identification of average and quantile treatment effects in the presence of the double selection problem into (i) a selective subpopulation (e.g., working—selection on unobservables) and (ii) a binary treatment (e.g., training—selection on observables) based on weighting observations by the inverse of a nested propensity score that characterizes either selection probability. Weighting estimators based on parametric propensity score models are applied to female labor market data to estimate the returns to education.  相似文献   
59.
Assume that there are two types of insurance contracts in an insurance company, and the ith related claims are denoted by {Xij, j ? 1}, i = 1, 2. In this article, the asymptotic behaviors of precise large deviations for non random difference ∑n1(t)j = 1X1j ? ∑n2(t)j = 1X2j and random difference ∑N1(t)j = 1X1j ? ∑N2(t)j = 1X2j are investigated, and under several assumptions, some corresponding asymptotic formulas are obtained.  相似文献   
60.
The construction and enumeration of (0, 1)-matrices with given line-sums is described for the rectangular cases often encountered in applications. Improved approximations are provided for the number of such matrices. Some new enumeration results for semi-regular bipartite graphs are included, and the related category of the quasi-semiregular bipartite graphs is recognized. The range of certain elements of products of a (0, I)-matrix is considered as a function of the line-sums. This, in turn, is related to the range in the numbers of interchanges available. Improvements in statistical practice that come from these constructions and enumerations are described.  相似文献   
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