An extensive power evaluation of some tests for the inverse Gaussian distribution

Many applications of the Inverse Gaussian distribution, including numerous reliability and life testing results are presented in statistical literature. The paper studies the problem of using entropy tests to examine the goodness of fit of an Inverse Gaussian distribution with unknown parameters. Some entropy tests based on different entropy estimates are proposed. Critical values of the test statistics for various sample sizes are obtained by Monte Carlo simulations. Type I error of the tests is investigated and then power values of the tests are compared with the competing tests against various alternatives. Finally, recommendations for the application of the tests in practice are presented.     

Variable screening for survival data in the presence of heterogeneous censoring

Variable screening for censored survival data is most challenging when both survival and censoring times are correlated with an ultrahigh-dimensional vector of covariates. Existing approaches to handling censoring often make use of inverse probability weighting by assuming independent censoring with both survival time and covariates. This is a convenient but rather restrictive assumption which may be unmet in real applications, especially when the censoring mechanism is complex and the number of covariates is large. To accommodate heterogeneous (covariate-dependent) censoring that is often present in high-dimensional survival data, we propose a Gehan-type rank screening method to select features that are relevant to the survival time. The method is invariant to monotone transformations of the response and of the predictors, and works robustly for a general class of survival models. We establish the sure screening property of the proposed methodology. Simulation studies and a lymphoma data analysis demonstrate its favorable performance and practical utility.     

Trade and poverty nexus: A case study of Sri Lanka

The link between trade liberalisation and poverty has become one of the most debated topics in recent years. There is a growing body of empirical literature on this topic and many studies provide mixed results. In this study, Sri Lanka is used as a detailed case study and a computable general equilibrium (CGE) approach is used as an analytical framework to examine the trade-poverty nexus. The results suggest that, liberalisation of the manufacturing industries is more pro-poor than that of the agricultural industries. Overall, this study suggests that trade reforms may widen the income gap between the rich and the poor creating uneven gains across different household groups in Sri Lanka. While short-term complementary policies are needed to compensate vulnerable income groups, long-term policies are needed to make gains from trade liberalisation more inclusive and equitable to maintain economic and political stability in Sri Lanka.     

彰显生命的本真——对庄子“吾丧我”生命哲学的解读

“吾”与“我”是先秦文献中重要的第一人称代词,但是二者在不同语境中却有着不同的含义。庄子“吾丧我”中的“吾”、“我”便具有各自的含义,“吾”为本真之我,“我”为遮蔽本真的现象之我。由于“我”存在有诸多的困境而导致“吾”不能获得自由和显现,因此,庄子通过“坐忘”、“心斋”的修行方法来彰显“吾”的存在,实现人的生命境界的提升。     

中国农业经济增长的空间分布及相关性——基于31个省区1985--2008年的面板数据分析

利用空间计量的方法,对中国1985--2008年31个省区农业经济发展的空间相关性、集聚特征及其空间动态演变趋势进行了分析和研究。研究结果表明,中国省际农业经济活动存在显著的非随机性空间集聚特征,存在小幅收敛趋势;东中部地区主要为高一高类型集聚区域,西部地区主要为低一低类型集聚区域,非典型省区较少;高一高集聚类型的集聚区域的空间联系带动力增强的趋势明显。     

身份认同与心理错位——基于高校"第二类贫困生"的实证研究

对长沙市高校贫困生群体进行抽样调查,结果发现高校“第二类贫困生”发生了自我认知偏差、态度偏激、行为偏执、人际关系偏离、排斥感趋强等表象特征的心理错位现象。身份认同是影响他们心理错位的一个重要因子。     

元代儒者价值观念中的"我"与"为我"——吴澄真儒观探析

在元代,儒者的价值观念发生了很大变化。这一变化可从其核心的主体意识和利益意识的变化中得到说明。元代著名理学家吴澄面对元代儒者所面临的价值危机,一方面以＂承继道统＂明确元代儒者的主体意识;另一方面以＂内圣外王＂规定元代儒者的利益意识,为元代儒者重新树立了＂真儒＂这一价值目标,肯定了元代儒者的人格自尊与价值自觉。     

新闻标题的内涵外延传承生成机制

本文根据新闻标题的类型,分析其生成机制,探讨为什么有些新闻标题按字面来看,说的似乎并不完全是稿件中提到的事,但事实上却跟稿件联系得非常紧密,而且准确地表达了新闻主题。本文运用＂内涵外延＂传承说对此做出详细的分析。本研究的目的是希望通过对新闻标题生成机制的分析,能成为从认知视角研究新闻标题的一种新思路。     

坝陵河大桥桥位风速观测及设计基准风速的计算

架设在峡谷上的大跨度桥梁,由于桥位处地形复杂,离谷底较高,设计基准风速一般无法通过抗风规范查得,需要进行专门的分析或测试。针对坝陵河大桥的设计基准风速问题,分别通过附近气象台站的数据和专门架设的观测塔的观测数据,通过分析得到了桥位处的设计基准风速。对类似地貌大桥建设设计基准风速的取得具有一定的参考意义。     

The use of spatial and randomisation-based methods for analysis of trials with treatments randomised into rows and columns

The effect of restricted randomisations on the validity and efficiency of using spatial model as well as more common analysis of variance methods for analysing field trials was examined by simulating yields in agricultural fields with known spatial variation and analysing those using eight different statistical models. Some of the models took into account the restrictions on the randomisation and some matched the true generated spatial variation. Two different types of spatial variations were generated. The results showed that the type I error was controlled if the correct spatial model was applied or if the model took into account the restrictions on the randomisation. If the model did not include the correct spatial model nor reflected the randomisation, the type I error could be much higher than the nominal value. The power of the tests could be increased if the model paid attention to the spatial variation. However, it may not always be possible to find the correct and true model. Therefore it is recommended that the random part of the model should reflect both the randomisation process and include terms that take into account spatial variation in the data in order to increase the power.