On hysteretic vector autoregressive model with applications

This paper proposes a new hysteretic vector autoregressive (HVAR) model in which the regime switching may be delayed when the hysteresis variable lies in a hysteresis zone. We integrate an adapted multivariate Student-t distribution from amending the scale mixtures of normal distributions. This HVAR model allows for a higher degree of flexibility in the degrees of freedom for each time series. We use the proposed model to test for a causal relationship between any two target time series. Using posterior odds ratios, we overcome the limitations of the classical approach to multiple testing. Both simulated and real examples herein help illustrate the suggested methods. We apply the proposed HVAR model to investigate the causal relationship between the quarterly growth rates of gross domestic product of United Kingdom and United States. Moreover, we check the pairwise lagged dependence of daily PM2.5 levels in three districts of Taipei.     

Graphical representation of survival curves in the presence of time-dependent categorical covariates with application to liver transplantation

Graphical representation of survival curves is often used to illustrate associations between exposures and time-to-event outcomes. However, when exposures are time-dependent, calculation of survival probabilities is not straightforward. Our aim was to develop a method to estimate time-dependent survival probabilities and represent them graphically. Cox models with time-dependent indicators to represent state changes were fitted, and survival probabilities were plotted using pre-specified times of state changes. Time-varying hazard ratios for the state change were also explored. The method was applied to data from the Adult-to-Adult Living Donor Liver Transplantation Cohort Study (A2ALL). Survival curves showing a ‘split’ at a pre-specified time t allow for the qualitative comparison of survival probabilities between patients with similar baseline covariates who do and do not experience a state change at time t. Time since state change interactions can be visually represented to reflect changing hazard ratios over time. A2ALL study results showed differences in survival probabilities among those who did not receive a transplant, received a living donor transplant, and received a deceased donor transplant. These graphical representations of survival curves with time-dependent indicators improve upon previous methods and allow for clinically meaningful interpretation.     

A new infinitely divisible discrete distribution with applications to count data modeling

A new discrete distribution involving geometric and discrete Pareto as special cases is introduced. The distribution possesses many interesting properties like decreasing hazard rate, zero vertex uni-modality, over-dispersion, infinite divisibility and compound Poisson representation, which makes the proposed distribution well suited for count data modeling. Other issues including closure property under minima, comparison of its distribution tail with other distributions via actuarial indices are discussed. The method of proportion and maximum likelihood method are presented for parameter estimation. Finally the performance of the proposed distribution over other classical and newly proposed infinitely divisible distributions are discussed.     

A new aging concept derived from the increasing convex ordering

In this paper, a comparison between the life distribution of a new unit with that of a used unit in the increasing convex order is made leading to a new class of life distributions which we call “new better than used in convex ordering of second order”. This class includes as subclasses the NBU and the NBUC and is a subclass of the NBUCA class. Preservation properties under convolution, random maxima, mixing and formation of coherent structures are established. Stochastic comparisons of the excess lifetime when the inter-arrival times belong to the NBUC(2) class are developed. Some applications of Poisson shock models and a test of exponentiality against NBUC(2) alternative are presented.     

On approximations via convolution-defined mixture models

An often-cited fact regarding mixing or mixture distributions is that their density functions are able to approximate the density function of any unknown distribution to arbitrary degrees of accuracy, provided that the mixing or mixture distribution is sufficiently complex. This fact is often not made concrete. We investigate and review theorems that provide approximation bounds for mixing distributions. Connections between the approximation bounds of mixing distributions and estimation bounds for the maximum likelihood estimator of finite mixtures of location-scale distributions are reviewed.     

在现实主义和现代主义的视野里寻求和谐生存之道——论D·H·劳伦斯的《儿子与情人》

D.H.劳伦斯在小说《儿子与情人》中,通过批判现实主义手法描述了主人公保罗的爱情悲剧和家庭悲剧,揭示了英国工业文明对自然环境及人类和谐生存状态的破坏。同时,作为一个现代主义作家,劳伦斯探索了人的潜意识及如何在现代文明中构建和谐生存之道。劳伦斯认为,人类只有与自然界保持和谐的关系、重建两性之间和谐、自然的关系,才能克服现代文明社会带来的弊端,实现生存状态的和谐。劳伦斯对人类生存困境的探索不仅为同时代人提供了获得救赎的全新思路,在当今呼唤和谐社会的时代,仍为我们提供了有益的借鉴。     

《无名的裘德》中的主题悖论

《无名的裘德》是一部杰出的现实主义作品,是哈代“性格与环境”小说中极为成功的一部。小说通过“主题对立”这一艺术手法深刻地揭示了人性,暴露了人类社会中许多错综复杂的关系,揭示了人类生存与存在中的一系列悖论,显示出极大的反讽效果。     

农村人口流迁动因研究评说

关于乡—城人口流迁的动因,历来为国内外学者所重视,研究成果颇多。那么迄今为止,都有哪些关于人口流迁动因的理论和观点?这些理论和观点能否完全解释20世纪80年代中后期中国的农村人口流迁现象?这些众多的理论和观点可以概括为三种:第一,宏观社会结构影响说;第二,生存与发展困境说;第三,劳动力剩余说。这三派观点各自都在自己所限定的范围内从一般意义上较为可信地解释了农村人口流迁的原因,但是由于方法论上的整体主义与个体主义的矛盾等原因,这些观点又有其局限性,因此,我们在借鉴这些观点解释20世纪80年代中后期以来中国农民的流迁动因的时候,应持审慎的态度。     

大学生网络化生存与理想信念教育

网络带来了传播方式和教育形式的革命性变化,大学生网络化生存挑战着高校理想信念教育,我国高校应该跟上时代步伐,充分利用互联网对大学生进行理想信念教育,要突出责任观,确立理论信念教育网络文化理念;创新方式方法,拓展理论信念网络文化教育平台;整合资源渠道,建立网络理想信念教育人才体系;注重传播艺术,提高网络理想信念教育的实效性和吸引力;制定网络规范,建立网络理想信念教育安全防犯体系。     

对《野性的呼唤》中巴克形象的再解读

《野性的呼唤》是美国著名作家杰克.伦敦的作品。小说描写一只名叫巴克的狗被骗卖到北方之后逐渐由狗变成狼的过程。该文通过对巴克形象的塑造,以狗喻人,来反映作者对现实“文明社会”的看法,阐述自己的人生哲学。