Kurtosis modelling by means of the J-transformation

Summary: The H–family of distributions or H–distributions, introduced by Tukey (1960; 1977), are generated by a single transformation of the standard normal distribution and allow for leptokurtosis represented by the parameter h. Alternatively, Haynes et al. (1997) generated leptokurtic distributions by applying the K–transformation to the normal distribution. In this study we propose a third transformation, the so–called J–transformation, and derive some properties of this transformation. Moreover, so-called elongation generating functions (EGFs) are introduced. By means of EGFs we are able to visualize the strength of tail elongation and to construct new transformations. Finally, we compare the three transformations towards their goodness–of–fit in the context of financial return data.     

Unequal at the Starting Line: Creating Participatory Inequalities across Generations and among Groups

We investigate how inequalities in political participation are shaped across generations by considering the influence of family background--in particular, parents' education and political involvement--on political participation. We pursue this issue, first, for individuals, investigating the effects of parental characteristics on the participatory profile of their offspring. Then, we use what we have learned to understand how group differences in political participation--between women and men and among Latinos, African Americans, and Anglo Whites--are rooted in the legacy of class and political background and in experiences throughout the life cycle.     

一种求解双目标线性规划的方法及其在上海市土地使用和交通方面的应用

本文介绍了一种求解双目标线性规划(SBLP)的方法.根据上海市土地使用与交通的现状建立了一个拟动态的模型(BOLT),并用该方法加以求解。根据得到的解对上海市土地使用与交通相互作用的情况进行了分析。     

普通野生稻和药用野生稻种子休眠性的研究

对普通野生稻和药用野生稻种子休眠的原因进行了探讨,表明野生稻种的遗传特性、形态性状、颖壳的透性和种子的生理特性与种子休眠有关。研究结果为打破野生稻种子休眠、提高其发茅力提供了依据和适宜的方法。     

网络教育的成本与效益分析

在分析网络教育的特点及发展趋势的基础上 ,对网络教育的成本与效益及相关性问题进行了探讨 ,并提出了网络教育成本分担 ,阐述了通过提高网络教育的利用效率与效益 ,降低网络教育直接成本 ,促进网络教育持续不断发展     

中美国家应急管理机制比较研究

针对学术界在国家应急管理机制研究方面缺乏全面比较分析的问题,文章运用比较分析方法研究了中美两国国家应急管理机制在组织机构、行动程序与法律保障三个方面的差异。通过研究提出,中国国家应急管理机制应在“设立应急管理协调机构”、“提高应急管理行动的计划性”、“制定应急管理纲领性法律”三个方面加以改进的建议。     

献给爷爷毛泽东主席的生日礼物-- 我心中的话

毛泽东思想,特别是毛泽东的军事思想是人类科学的思想体系,我在完成博士学业的过程中,十分认真和努力学习、研究这个体系,并以客观公正的态度来进行研究和评价.爷爷毛泽东,对国际风云有着深刻敏锐的洞察力,他创造的军事理论成果,对世界产生了重大影响.毛泽东的军事思想,是我国新时期制胜卫国之宝,也将永远是世界人民反对以强凌弱的锐利武器.     

德国应用技术大学的教学体系及其借鉴意义

德国应用技术大学(Fachhochscule)具有专业性、应用性、地域性等特征。文章研究了德国应用技术大学的学制、教学目标、课程体系及其实践教学的特点，并从教学安排、课程体系及实践教学三个方面与我国的情况进行了对比，在此基础上分析总结了其成功的经验及对我国普通高等工科院校教学改革的借鉴意义。     

HEAVY-TAILED-DISTRIBUTED THRESHOLD STOCHASTIC VOLATILITY MODELS IN FINANCIAL TIME SERIES

To capture mean and variance asymmetries and time‐varying volatility in financial time series, we generalize the threshold stochastic volatility (THSV) model and incorporate a heavy‐tailed error distribution. Unlike existing stochastic volatility models, this model simultaneously accounts for uncertainty in the unobserved threshold value and in the time‐delay parameter. Self‐exciting and exogenous threshold variables are considered to investigate the impact of a number of market news variables on volatility changes. Adopting a Bayesian approach, we use Markov chain Monte Carlo methods to estimate all unknown parameters and latent variables. A simulation experiment demonstrates good estimation performance for reasonable sample sizes. In a study of two international financial market indices, we consider two variants of the generalized THSV model, with US market news as the threshold variable. Finally, we compare models using Bayesian forecasting in a value‐at‐risk (VaR) study. The results show that our proposed model can generate more accurate VaR forecasts than can standard models.     

Test for homogeneity in Hardy–Weinberg normal mixture model

The phenotype of a quantitative trait locus (QTL) is often modeled by a finite mixture of normal distributions. If the QTL effect depends on the number of copies of a specific allele one carries, then the mixture model has three components. In this case, the mixing proportions have a binomial structure according to the Hardy–Weinberg equilibrium. In the search for QTL, a significance test of homogeneity against the Hardy–Weinberg normal mixture model alternative is an important first step. The LOD score method, a likelihood ratio test used in genetics, is a favored choice. However, there is not yet a general theory for the limiting distribution of the likelihood ratio statistic in the presence of unknown variance. This paper derives the limiting distribution of the likelihood ratio statistic, which can be described by the supremum of a quadratic form of a Gaussian process. Further, the result implies that the distribution of the modified likelihood ratio statistic is well approximated by a chi-squared distribution. Simulation results show that the approximation has satisfactory precision for the cases considered. We also give a real-data example.