Bayesian palaeoclimate reconstruction

Summary.  We consider the problem of reconstructing prehistoric climates by using fossil data that have been extracted from lake sediment cores. Such reconstructions promise to provide one of the few ways to validate modern models of climate change. A hierarchical Bayesian modelling approach is presented and its use, inversely, is demonstrated in a relatively small but statistically challenging exercise: the reconstruction of prehistoric climate at Glendalough in Ireland from fossil pollen. This computationally intensive method extends current approaches by explicitly modelling uncertainty and reconstructing entire climate histories. The statistical issues that are raised relate to the use of compositional data (pollen) with covariates (climate) which are available at many modern sites but are missing for the fossil data. The compositional data arise as mixtures and the missing covariates have a temporal structure. Novel aspects of the analysis include a spatial process model for compositional data, local modelling of lattice data, the use, as a prior, of a random walk with long-tailed increments, a two-stage implementation of the Markov chain Monte Carlo approach and a fast approximate procedure for cross-validation in inverse problems. We present some details, contrasting its reconstructions with those which have been generated by a method in use in the palaeoclimatology literature. We suggest that the method provides a basis for resolving important challenging issues in palaeoclimate research. We draw attention to several challenging statistical issues that need to be overcome.     

A group sequential test for the inverse Gaussian mean

The present paper deals with the development of a group sequential test when response variable has an inverse Gaussian distribution with known scale parameter.     

快速傅里叶变换在导热逆问题中的应用

本文用通过快速傅里叶变换来进行逆拉氏变换的方法解决导热逆问题。众所周知,内点温度的测量误差往往导致导热逆问题计算的不稳定。作者用频谱分析的概念解决了这一困难。文中提出了测量温度时固体内点不同位置、内点温度的测量误差以及数值计算可采用的时间步长之间的关系。计算实例表明,本文所提供的方法对于瞬变现象的研究有很大的实用价值。     

再论耕地资源的保护

耕地是人类社会生产和生活的基础。我国耕地资源的保护对本民族生存和国民经济的发展以及我国农业可持续发展战略具有重要意义。目前，人们对耕地资源保护在认识、技术、投入等方面存在着不同程度的问题。针对这些问题应采取思想教育、法律、行政、技术等综合措施，以保护耕地资源的数量、质量和生态系统。     

和谐社会模式下的环境政策分析

环境是人类赖以生存的基本条件。在当今世界,新的环境危机使经济社会的可持续发展受到严重地制约。以我国建设和谐社会为契机,从环境问题与环境政策的关系入手,来分析我国环境政策的现状,提出,为实现人与自然之间的和谐发展人类所应该采取的3种正确态度。在综合分析的基础上, 提出了7条有助于在我国建设和谐社会的环境政策建议。     

现行生育保险制度亟待解决的问题及改进对策

目前我国的生育保险制度存在发展不平衡,覆盖面不广,基金筹集渠道窄,待遇标准不统一,管理手段落后等问题,对此,建议采取加大宣传力度,强化生育保险意识,实行社会统筹制度,加快法制建设等有效措施,完善我国的生育保险制度。     

高校青年教师入党问题分析

本文结合当前高校党的建设的实际 ,对高校青年教师入党积极性不高的现状进行了分析和思考 ,提出了进一步解放思想 ,突破“左”的思维习惯禁锢 ,加强思想政治工作 ,提高青年教师入党积极性 ,开创培养和发展青年教师入党工作新局面的工作对策。     

Robustness of the linear discriminant function to nonnormality: Johnson's system

The asymptotic distribution of the Errors of Misclassification in using the Linear Discriminant Function is investigated here. The purpose is to study the effects of nonnormality on these errors. The class of distributions considered is the Johnson's system. Each of the three random variables can be transformed to normality. In one particular case numerical evaluations are made, based on which it is possible to recommend whether or not it is necessary to make the transformation prior to classification. In a parallel study, we present similar results for the Edgeworth Series distribution, where the random variables cannot be transformed to normality.     

Characteristics of Older Adult Problem Gamblers Calling a Gambling Helpline

Background Few investigations have characterized groups of older adults with gambling problems, and published reports are currently limited by small samples of older adult problem gamblers. Gambling helplines represent a widespread mechanism for assisting problem gamblers to move into treatment settings. Given data from older adult problem gamblers in treatment, we hypothesized that older as compared with younger adult problem gamblers calling a gambling helpline would be less likely to report gambling-related problems.Design and methods Logistic regression analyses were performed on data obtained from January 1, 2000 to December 31, 2001, inclusive, from callers with gambling problems (N = 1,084) contacting the Connecticut Council on Problem Gambling Helpline.Results Of the 1,018 phone calls used in the logistic regression analyses, 168 (16.5%) were from older adults and 850 (83.5%) from younger adults. Age-related differences were observed in demographic features, types and patterns of gambling reported as problematic, gambling-related problems and psychiatric symptoms, substance use problems, patterns of indebtedness, and family histories of addictive disorders. Older as compared with younger adult problem gamblers were more likely to report having lower incomes, longer durations of gambling, fewer types of problematic gambling, and problems with casino slot machine gambling and less likely to report gambling-related anxiety, family problems, illegal behaviors and arrests, drug problems, indebtedness to bookies or acquaintances, family histories of drug abuse, and problems with casino table gambling.Conclusions Older as compared with younger adult problem gamblers calling a gambling helpline differ on many clinically relevant features. The findings suggest the need for improved and unique prevention and treatment strategies for older adults with gambling problems.     

It’s Not What You Know, but How You Use It: Statistical Knowledge and Adolescent Problem Gambling

This paper examined the nature of irrational gambling-related cognitions in a sample of 926 adolescents (mean age = 14.5 years) sampled from Australian schools. Students were differentiated according to gambling status and administered a series of items that assessed their understanding of objective odds, the nature of randomness, the role of skill in gambling, and the perceived profitability of gambling. The results confirmed previous findings that problem gamblers tend to be more irrational in their perceptions, as indicated by stronger beliefs in the role of skilful play in chance activities, and that gambling is a potentially profitable activity. However, counter intuitively, problem gamblers did not appear to have any poorer understanding of objective probabilities. These results are discussed in terms of Sevigny and Ladouceur’s (2004) concept of cognitive switching as well as psychological research concerning the role of emotional and motivational factors in the development of an illusion of control. The implications of these findings for gambling education programs are discussed.