Spatio-temporal modeling and prediction of CO concentrations in Tehran city

One of the most important agents responsible for high pollution in Tehran is carbon monoxide. Prediction of carbon monoxide is of immense help for sustaining the inhabitants’ health level. In this paper, motivated by the statistical analysis of carbon monoxide using the empirical Bayes approach, we deal with the issue of prior specification for the model parameters. In fact, the hyperparameters (the parameters of the prior law) are estimated based on a sampling-based method which depends only on the specification of the marginal spatial and temporal correlation structures. We compare the predictive performance of this approach with the type II maximum likelihood method. Results indicate that the proposed procedure performs better for this data set.     

Moments of sample moments

The problem offinding expressions for sampling moments of sample moments has been ahistorically old one. This problem is treated here, with the use of partitions and multi partitions , for the univariate as well as the multivariate case. The systematic combinatorial approach minimizes the chance of omitting any

contributions and making errors in their computation. Componentwise identification is made possible , soerrors can be located. From the complete set of general moment formulae, s pecial cases may be obtained by identifying identical variables.     

On the use and evaluation of prospective scan methods for health-related surveillance

Summary.  We review some prospective scan-based methods that are used in health-related applications to detect increased rates of mortality or morbidity and to detect bioterrorism or active clusters of disease. We relate these methods to the use of the moving average chart in industrial applications. Issues that are related to the performance evaluation of spatiotemporal scan-based methods are discussed. In particular we clarify the definition of a recurrence interval and demonstrate that this measure does not reflect some important aspects of the statistical performance of scan-based, and other, surveillance methods. Some research needs in this area are given.     

矩阵方幂之和

At，Bt为m阶矩阵，rt，dt，ft，vt等为正整数（t＝1，2，…，s）．给出下列矩阵方幂和计算公式。     

Least absolute values estimation: an introduction

A brief review and bibliography of least absolute values (LAV) estimation is given. This paper serves to introduce the other articles in this special issue on the computational aspects of LAV estimation.     

De Morgan in the prehistory of statistical hypothesis testing

Summary.  Whereas the research of the 19th-century mathematician Augustus De Morgan in formal logic is fairly familiar to historians of mathematics, his work in probability is largely unknown to the modern reader. For this reason, few would be aware that this work contains a self-admitted error in probabilistic reasoning. This mistake is intriguing not only because it features in the work of someone who was so expert in logic but also because it appears to be an early example of hypothesis testing, which was a topic of much controversy in the development of mathematical statistics in the 20th century. The paper examines the mathematical and historical details of De Morgan's error.     

Asymptotic efficiency of majority rule relative to rank-sum method for selecting the best population

The ranking and selection problem has been well-studied in the case of continuous responses. In this paper, we address the situation in which continuous responses are replaced by discrete orderings. When individuals in the population provide exhaustive rank-orderings of the alternatives, two common decision rules are the majority rule and the rank-sum method. In the former case, the alternative receiving the most first-place votes is declared superior, while in the latter, the alternative with the smallest rank-sum is deemed the best. Both the Pitman efficiencies and the lower bounds on Bahadur efficiencies of the majority rule relative to the rank-sum method are derived, assuming that the rank data are generated from either the Plackett–Luce or the translative strengths models. In addition, finite sample properties of the two methods are compared with the maximum likelihood approach through simulation studies. Our results suggest two things. First, when it is substantially more difficult to obtain a complete rank-ordering than simply the top choice, the majority rule performs adequately and efforts would be better spent asking many voters to provide top choice rather than fewer voters to provide complete orderings. Second, the rank-sum rule compares favorably to, and is substantially more robust than, the maximum likelihood approach.     

党的建设面临的新的历史性课题——搞好党的第三代领导集体理论贡献的概括和总结

以江泽民为核心的党的第三代领导集体无论是在高举邓小平理论伟大旗帜方面,还是在丰富和发展邓小平理论乃至毛泽东思想、马克思列宁主义方面,都做出了许多理论贡献.必须对党的第三代领导集体的这些理论贡献给予概括和总结,为此本文进行了探讨,并提出了一些具体的思路.     

Asymptotic separability in sensitivity analysis

In an observational study in which each treated subject is matched to several untreated controls by using observed pretreatment covariates, a sensitivity analysis asks how hidden biases due to unobserved covariates might alter the conclusions. The bounds required for a sensitivity analysis are the solution to an optimization problem. In general, this optimization problem is not separable, in the sense that one cannot find the needed optimum by performing a separate optimization in each matched set and combining the results. We show, however, that this optimization problem is asymptotically separable, so that when there are many matched sets a separate optimization may be performed in each matched set and the results combined to yield the correct optimum with negligible error. This is true when the Wilcoxon rank sum test or the Hodges-Lehmann aligned rank test is applied in matching with multiple controls. Numerical calculations show that the asymptotic approximation performs well with as few as 10 matched sets. In the case of the rank sum test, a table is given containing the separable solution. With this table, only simple arithmetic is required to conduct the sensitivity analysis. The method also supplies estimates, such as the Hodges-Lehmann estimate, and confidence intervals associated with rank tests. The method is illustrated in a study of dropping out of US high schools and the effects on cognitive test scores.     

矢量法判定分子极性在中学化学中的应用

给出了一种通过不同类型分子的空间结构求算分子中键长的矢量和进而得到一个判断分子极性新判据的方法