The laws of large numbers for Pareto-type random variables with infinite means

In this paper, we consider the laws of large numbers for NSD random variables satisfying Pareto-type distributions with infinite means. Based on the Pareto-Zipf distributions, some weak laws of large numbers for weighted sums of NSD random variables are obtained. Meanwhile, we show that a weak law for Pareto-Zipf distributions cannot be extended to a strong law. Furthermore, based on the two tailed Pareto distribution, a strong law of large numbers for weighed NSD random variables is presented. Our results extend the corresponding earlier ones.     

The covariance of the backward and forward recurrence times in a renewal process: the stationary case and asymptotics for the ordinary case

In a Poisson process, it is well-known that the forward and backward recurrence times at a given time point t are independent random variables. In a renewal process, although the joint distribution of these quantities is known (asymptotically), it seems that very few results regarding their covariance function exist. In the present paper, we study this covariance and, in particular, we state both necessary and sufficient conditions for it to be positive, zero or negative in terms of reliability classifications and the coefficient of variation of the underlying inter-renewal and the associated equilibrium distribution. Our results apply either for an ordinary renewal process in the steady state or for a stationary process.     

A volume based approach to establish B-spline based expressions for density functions and its application to progressive hybrid censoring

We propose an approach to determine the distribution of particular linear combinations of hybrid censored order statistics which is based on the calculation of volumes of polytopes. For this purpose, we establish efficient and compact volume formulas in terms of B-splines. Further, we illustrate our approach for ten different progressive hybrid censoring schemes under an exponential assumption.     

基于广义误差分布的股票收益率波动特征分析

假设股票收益率序列服从具有厚尾特征的GED分布,利用多种非对称性模型描述和检验了沪市股票日收益率序列的波动性特征,发现股票价格波动具有条件异方差性,并通过对股票市场信息影响曲线的分析,刻画了沪市股票价格波动中的显著非对称性。这说明股市波动对于不同的政策干预和信息冲击具有不同程度的反应,且非对称性的方向与以往结论有所不同,说明我国股市风险变异特征和收益状况在不断的发生变化,＂利好消息＂对股市的刺激作用需要其他市场干预的配合才能发挥出来。     

体制改革、消费主导与经济发展方式转变

无论是从马克思主义理论和科学发展观的要求来看,还是从我国现实经济的发展要求来看,着力推进消费主导的经济发展方式转变,都已经作为一个事关我国现代化建设全局的重大任务被提了出来。为此,我们应针对扩大居民消费的几种主要障碍,下决心推进我国政治体制和经济体制的改革,从制度上解决与社会主义本质完全背离的国民财富分配不公问题和灰色收入问题。     

Malaria in Pacific populations: seen but not heard?

Most Pacific Island countries are located in the tropics, where there is an abundance of mosquitoes with the potential to carry debilitating or life-threatening vector-borne diseases. This article examines three Melanesian countries in which malaria is endemic—Papua New Guinea, Solomon Islands and Vanuatu—but the threat posed by the spread of malaria gives the issues a broader significance to the Pacific region. After discussing the spatial distribution and prevalence of malaria in the Pacific, the article examines a number of health interventions through which people have sought to control malaria. Although the disease was nearly eradicated in the Pacific in the 1970s, it is no longer in retreat. The article concludes by examining why there are still grounds for cautious optimism, and the challenges that Pacific Island countries face in reducing the impact of malaria on their populations. There is a need for prompt and concerted action on malaria at the national, regional and international levels if the public health concerns arising from the disease are to be adequately addressed.     

泛渤海区域空间结构调整基本思路研究

划分区域的目的就是要政府协调解决其内部存在的主要矛盾和问题。立足于环渤海地区需要协调解决的突出问题,首先分析指出环渤海的范围主要应包括北京、天津、河北、山东、山西、内蒙中部4市,而不应包括辽宁。为与通常意义的环渤海有所区别,建议用“泛渤海”指代该区域。结合区域内现有的空间结构和发展趋势,提出了按照“四区五带”的总体空间架构调整目前的空间结构。随后的分析中重点阐释了城镇体系和产业布局的基本思路。     

Accelerated test system strength models based on Birnbaum–Saunders distribution: a complete Bayesian analysis and comparison

Several models for studies related to tensile strength of materials are proposed in the literature where the size or length component has been taken to be an important factor for studying the specimens’ failure behaviour. An important model, developed on the basis of cumulative damage approach, is the three-parameter extension of the Birnbaum–Saunders fatigue model that incorporates size of the specimen as an additional variable. This model is a strong competitor of the commonly used Weibull model and stands better than the traditional models, which do not incorporate the size effect. The paper considers two such cumulative damage models, checks their compatibility with a real dataset, compares them with some of the recent toolkits, and finally recommends a model, which appears an appropriate one. Throughout the study is Bayesian based on Markov chain Monte Carlo simulation.     

The generalized log-gamma mixture model with covariates: local influence and residual analysis

In a sample of censored survival times, the presence of an immune proportion of individuals who are not subject to death, failure or relapse, may be indicated by a relatively high number of individuals with large censored survival times. In this paper the generalized log-gamma model is modified for the possibility that long-term survivors may be present in the data. The model attempts to separately estimate the effects of covariates on the surviving fraction, that is, the proportion of the population for which the event never occurs. The logistic function is used for the regression model of the surviving fraction. Inference for the model parameters is considered via maximum likelihood. Some influence methods, such as the local influence and total local influence of an individual are derived, analyzed and discussed. Finally, a data set from the medical area is analyzed under the log-gamma generalized mixture model. A residual analysis is performed in order to select an appropriate model. The authors would like to thank the editor and referees for their helpful comments. This work was supported by CNPq, Brazil.     

分税制以后我国财权配置问题实证研究

1994年推行的分税制是不彻底的,财权配置缺乏协调性和统一性,致使各级政府在公共产品和服务提供中责权利不对称。因此,需要调整财权配置,以保证事权和财权的统一。