Optimal B-robust estimators for the parameters of the Burr XII distribution

The Burr XII distribution offers a flexible alternative to the distributions that play important role for modelling data in reliability, risk and process capability. However, estimating the shape parameters of the Burr XII distribution is a challenging problem. The classical estimation methods such as maximum likelihood and least squares are often used to estimate the parameters of the Burr XII distribution, but these methods are very sensitive to the outliers in the data. Thus, a robust estimation method alternative to the classical methods is needed to find robust estimators that are less sensitive to the outliers in the data. The purpose of this paper is to use the optimal B-robust estimation method [Hampel FR, Ronchetti EM, Rousseeuw PJ, Stahel WA. Robust statistics: the approach based on influence functions. New York: Wiley; 1986] to obtain robust estimators for the shape parameters of the Burr XII distribution. The simulation results show that the optimal B-robust estimators generally outperform the classical estimators in terms of the bias and root mean square errors when there are outliers in data.     

A new lifetime distribution

Many if not most lifetime distributions are motivated only by mathematical interest. Here, a new three-parameter distribution motivated mainly by lifetime issues is introduced. Some properties of the new distribution including estimation procedures, univariate generalizations and bivariate generalizations are derived. A real data application is described to show its superior performance versus at least that of 15 of the known lifetime models.     

A likelihood ratio test to discriminate exponential–Poisson and gamma distributions

The exponential–Poisson (EP) distribution with scale and shape parameters β>0 and λ∈?, respectively, is a lifetime distribution obtained by mixing exponential and zero-truncated Poisson models. The EP distribution has been a good alternative to the gamma distribution for modelling lifetime, reliability and time intervals of successive natural disasters. Both EP and gamma distributions have some similarities and properties in common, for example, their densities may be strictly decreasing or unimodal, and their hazard rate functions may be decreasing, increasing or constant depending on their shape parameters. On the other hand, the EP distribution has several interesting applications based on stochastic representations involving maximum and minimum of iid exponential variables (with random sample size) which make it of distinguishable scientific importance from the gamma distribution. Given the similarities and different scientific relevance between these models, one question of interest is how to discriminate them. With this in mind, we propose a likelihood ratio test based on Cox's statistic to discriminate the EP and gamma distributions. The asymptotic distribution of the normalized logarithm of the ratio of the maximized likelihoods under two null hypotheses – data come from EP or gamma distributions – is provided. With this, we obtain the probabilities of correct selection. Hence, we propose to choose the model that maximizes the probability of correct selection (PCS). We also determinate the minimum sample size required to discriminate the EP and gamma distributions when the PCS and a given tolerance level based on some distance are before stated. A simulation study to evaluate the accuracy of the asymptotic probabilities of correct selection is also presented. The paper is motivated by two applications to real data sets.     

论行政诉讼非法证据类型

非法证据排除规则最早在美国确立并得到发展,形成一套比较完整的体系。我国对非法证据排除规则的探讨很长时期仅停留在理论阶段,2012年《刑事诉讼法》修改中采纳并确立这一证据规则,使其从理论探讨变为实践,也为行政诉讼非法证据排除规则的探讨提供了很好的借鉴。目前,行政诉讼法正处于修改时期,以现有的法律规范为基础探讨行政诉讼非法证据的类型及其判断标准显得尤为必要。     

Reliability of stress–strength model for exponentiated Pareto distributions

In this paper, the reliability of a system is discussed when the strength of the system and the stress imposed on it are independent, non-identical exponentiated Pareto distributed random variables. Different point estimations and interval estimations are proposed. The point estimators obtained are maximum likelihood, uniformly minimum variance unbiased and Bayesian estimators. The interval estimations obtained are approximate, exact, bootstrap-p and bootstrap-t confidence intervals and Bayesian credible interval. Different methods and the corresponding confidence intervals are compared using Monte-carlo simulations.     

The labour market flexibility debate in India: Re‐examining the case for signing voluntary contracts

A major focus of India's ongoing policy debate over labour market flexibilization has been the statutory requirement that firms employing 100 or more workers cannot dismiss employees without prior government permission. The case for repealing that requirement (or greatly increasing the workforce threshold) is notably underpinned by Basu, Fields and Debgupta (2009). Here, the author challenges their particular theoretical argument for hiring and firing at will based on the voluntary signing of contracts, demonstrating that their general policy conclusion is logically unsustainable even within the framework of that model. The case for labour market flexibilization through voluntary contracting thus remains unfounded.     

Prediction intervals for future Weibull residual data

In reliability theory, risk analysis, renewal processes and actuarial studies, the residual lifetimes data play an important essential role in studying the conditional tail of the lifetime data. In this paper, based on some observed ordered residual Weibull data, we introduce different prediction methods for obtaining prediction intervals (PIs) of future residual lifetimes including likelihood, Wald, moments, parametric bootstrap, and highest conditional methods. Monte Carlo simulations are performed to compare the performances of the so obtained PIs and one data analysis is performed for illustration purposes.     

长期股权投资准则修订变化及对企业财务的影响研究

2014年7月1日,新修订的企业会计准则率先在所有执行企业会计准则的企业范围内施行,这意味着企业的财务核算、财务报表等面临新的问题和挑战.长期股权投资是企业会计核算中的重点和难点,其会计核算方法比较复杂,不同的会计核算会对企业的财务产生不同的影响.本次长期股权投资的修订,规范了长期股权投资的会计核算方法,使其持续趋同于国际会计准则,有利于我国对外经济合作,有利于适应社会经济的发展.本文主要剖析了长期股权投资准则修订前后的变化,对其主要会计核算进行举例分析,并分析其对企业财务的影响.     

A new generalization of alpha-skew-normal distribution

In this paper, a new generalization of alpha-skew-normal distribution is considered. Some properties of this distribution, which is denoted by GASN(α, λ), including moments, maximum likelihood estimation of parameters, and some other properties are studied. Finally, using a real data set, we show that our new distribution is the best-fitted distribution for the used data among normal, skew normal, alpha-skew-normal, and skew-bimodal-normal distributions.     

论老年人犯罪从宽暨免死的年龄标准与立法模式——以《刑法修正案(八)》为视角

老年人犯罪从宽的年龄标准应当有别于老年人免死的年龄标准。当前,中国对老年人犯罪从宽的年龄宜规定为"年满70周岁",而对老年人犯罪免死的年龄则宜规定为"年满75周岁"。对老年人犯罪从宽应当与对未成年人犯罪从宽相一致,统一规定为"应当从轻或者减轻处罚",而没有必要区分故意和过失犯罪分别规定。考虑到老年人犯罪免死的根据、刑罚目的和国际上的普遍做法,中国应当免除所有老年人犯罪的死刑,而不应有例外。