Panel LM unit root tests with level and trend shifts

This paper considers a Lagrange multiplier (LM) based panel unit root test that allows for heterogeneous structural breaks in both the intercepts and slopes of a series. We note that many popular time series variables are likely to exhibit changing means and/or trends over time. Given that the usual tests will depend on the nuisance parameters indicating the locations of the trend breaks, we adopt a transformation procedure that makes our new panel unit root tests invariant to the nuisance parameters. To illustrate the importance of the power gain provided by our test, we examine the convergence hypothesis using relative ratios of per capita health care expenditures in 20 OECD countries. Our results provide evidence that the convergence hypothesis is supported.     

The Importance of Professional Training for Test Writers

The importance of language testing is noticed by more and more people.But the quality of testing,or say,the level of test writers,has been ignored for a long time.This article intends to talk about the importance of professional training for test writ- ers,in order to arouse people＇s attention to the quality of test designers.     

Predicting the geo-temporal variations of crime and disorder

Traditional police boundaries—precincts, patrol districts, etc.—often fail to reflect the true distribution of criminal activity and thus do little to assist in the optimal allocation of police resources. This paper introduces methods for crime incident forecasting by focusing upon geographical areas of concern that transcend traditional policing boundaries. The computerised procedure utilises a geographical crime incidence-scanning algorithm to identify clusters with relatively high levels of crime (hot spots). These clusters provide sufficient data for training artificial neural networks (ANNs) capable of modelling trends within them. The approach to ANN specification and estimation is enhanced by application of a novel and noteworthy approach, the Gamma test (GT).     

A comparison of several approximations to the power function of the likelihood ratio test in covariance structure analysis*

In this paper we compare alternative asymptotic approximations to the power of the likelihood ratio test used in covariance structure analysis for testing the fit of a model. Alternative expressions for the noncentrality parameter (ncp) lead to different approximations to the power function. It appears that for alternative covariance matrices close to the null hypothesis, the alternative ncp's lead to similar values, while for alternative covariance matrices far from H_o the different expressions for the ncp can conflict substantively. Monte Carlo evidence shows that the ncp proposed in Satorra and Saris (1985) gives the most accurate power approximations.     

Testing for abnormal security-price performance under conditions of event-period uncertainty

This paper examines an event study test procedure based on cumulative average residuals (CARs) and a boundary-crossing probability for Brownian motion. The boundary-crossing test procedure is designed to detect abnormal security-price performance under conditions of event-period uncertainty. Simulations with daily security-return data show that the boundary-crossing test is well specified under the null hypothesis and has good power properties under the alternative hypothesis of abnormal security-price performance distributed over an event period of uncertain length.     

More on the correct use of omnibus tests for normality

This Monte Carlo study compares the small sample properties of some commonly used omnibus and directional tests, based on the standardized third and fourth moments, for assessing the normality of random variables: the omnibus D'Agostino K² test and the directional components, and three versions of the Jarque–Bera test.     

中国和新加坡产业内贸易与规模经济关系的协整分析

中国和新加坡产业内贸易与规模经济存在着一种长期的均衡关系,新加坡生产企业的规模经济对产业内贸易的推动作用大于中国,中国和新加坡生产企业的规模经济与产业内贸易存在单向因果关系,即规模经济促进产业内贸易.     

通用ATS实现技术研究

我国武器装备通用ATS(自动测试系统)经历了从引进、仿制到自行研制的过程，但是目前通用ATS总的局面是通用ATS不通用，这种局面主要是由于国内对通用ATS实现技术缺乏统一认识造成的。基于此，本文研究了与开发通用ATS密切相关的标准／规范、硬件配置技术、接口技术、集成测试软件开发环境技术。本文的研究结果适用于所有开发通用ATS的项目。     

Distribution-free tests for comparing several treatments with a control

Abstract  In this paper we propose distribution-free treatments versus control tests for the one- and two-way classifications. The null distribution properties are shown to be equivalent to those of well-known statistics for which critical values have been extensively tabled. Asymptotic relative efficiencies with respect to corresponding normal theory competitors are derived and optimal designs for the allocation of experimental units to the treatments and control are obtained.     

电信业顾客满意度测评指标体系的建立与检验

本文结合CS理论模型和电信业的具体业务,提出了电信业顾客满意度测评指标体系,并在预调查阶段运用信度分析和因子分析,证明了该指标体系的有效性和实用性.