Independence and Dependence in Aging

No abstract available for this article.     

A discussion of the question: for what use are tests of hypotheses and tests of significance

The author believes that tests provide a poor model of most real problems, usually so poor that their objectivity is tangential and often too poor to be useful.     

Crossing probabilities for a square root boundary by a bessel process

Probabilities for Wiener and Bessel processes to cross a square root boundary are calculated and the Mellin transform of the distribution of the associated stopping time is given.The transform is inverted and a table of critical values for the crossing probability as a function of the observation time is included. Also an analytic expression for the crossing probability is computed for the case of constant drift.     

On optimal tests for general interval-hypotheses

Optimal statistical tests, using the normality assumptions for general interval hypotheses including equivalence testing and testing for nonzero difference (or for non-unit) are presented. These tests are based on the decision theory for Polya Type distributions and are compared with usual confidence tests and with ’two one-sided tests’- procedures. A formal relationship between some optimal tests and the Anderson and Hauck procedure as well as a procedure recommended by Patel and Gupta is given. A new procedure for a generalisation of Student's test as well as for equivalence testing for thet-statistics is shown.     

Optimal sampling op hierarchical screening with inspection errors

For the multi-stage hierarchical Dorfman group testing problem, where inspection errors exist, we provide a simple procedure to determine the number to stages, the number of subgroups of each stage and sample size of each subgroup simultaneously. The optimal group testing plan established by this procedure minimizes the expected number of tests per item. This result can be easily extended to more general applications.     

Bootstrap test of goodness of fit to a linear model when errors are correlated

Given the regression model Y_i = m(x_i) +ε_i (x_i ε C, i = l,…,n, C a compact set in R) where m is unknown and the random errors {ε_i} present an ARMA structure, we design a bootstrap method for testing the hypothesis that the regression function follows a general linear model: H_o : m ε {mθ(.) = A^t(.)θ : θ ε ? ? R^q} with A a functional from R to R^q. The criterion of the test derives from a Cramer-von-Mises type functional distance D = d²([mcirc]_n, A^t(.)θ_n), between [mcirc]_n, a Gasser-Miiller non-parametric estimator of m, and the member of the class defined in H_o that is closest to m_n in terms of this distance. The consistency of the bootstrap distribution of D and θ_n is obtained under general conditions. Finally, simulations show the good behavior of the bootstrap approximation with respect to the asymptotic distribution of D = d².     

Statistical Adequacy and the Testing of Trend Versus Difference Stationarity

Abstract

The debate on whether macroeconomic series are trend or difference stationary, initiated by Nelson and Plosser [Nelson, C. R.; Plosser, C. I. (1982). Trends and random walks in macroeconomic time series: some evidence and implications. Journal of Monetary Economics10:139–162] remains unresolved. The main objective of the paper is to contribute toward a resolution of this issue by bringing into the discussion the problem of statistical adequacy. The paper revisits the empirical results of Nelson and Plosser [Nelson, C. R.; Plosser, C. I. (1982). Trends and random walks in macroeconomic time series: some evidence and implications. Journal of Monetary Economics10:139–162] and Perron [Perron, P. (1989). The great crash, the oil price shock, and the unit root hypothesis. Econometrica57:1361–1401] and shows that several of their estimated models are misspecified. Respecification with a view to ensuring statistical adequacy gives rise to heteroskedastic AR(k) models for some of the price series. Based on estimated models which are statistically adequate, the main conclusion of the paper is that the majority of the data series are trend stationary.     

技能大赛助推教改落地——以报关技能大赛为例

指导学生备赛过程中，我们发现了教学中存在的诸多问题，比如学生普遍存在理论与实际脱轨现象、职业素养欠缺、学生自主学习能力差动力不足等。以参加报关技能大赛为契机，通过课程设置、教学方法、考核方法等方面的顶层设计并将其成功的应用于教学实践。在此总结我们的经验，供同行参考。     

East African Mothers with HIV: Testing,Talking, and Transmission to Children

ABSTRACT

Experiences of African mothers with HIV can inform the development of services to prevent HIV transmission to children. A small qualitative study was conducted in Tanzania with six openly HIV-positive women. They suggest that counseling and HIV testing additionally benefit the mother beyond reducing HIV transmission to her child. They recommend that testing of couples would allow them to make plans and informed choices together concerning sexual behavior, childbearing, and prevention of HIV transmission to children.     

The American Revolutionary Period

The United States is currently experiencing the largest wave of immigration in its history. This contemporary immigration is unprecedented in its diversity of ethnicity, class, and countries of origin, and large urban areas are no longer alone in absorbing arrivals. The author reviews children's picture books about dilemmas that immigrant children face, such as being different, coping with great and small changes, responding to one's name, learning a new language, relating to previous generations and traditions, maintaining ties with distant relatives, and visiting their homelands. Classroom materials relevant to the social and cultural experiences of children generate interest in and enthusiasm about learning. When teachers include books about the negotiation of another culture in the curriculum, children learn through reading that stories can be about people like them, that stories of their experiences are worthy of being in a book, and that other children have felt the way they do.