Generalized Least Squares Estimation in Contingency Tables Analysis: Asymptotic Properties and Applications

Different sorts of bilinear models (models with bilinear interaction terms) are currently used when analyzing contingency tables: association models, correlation models... All these can be included in a general family of bilinear models: power models. In this framework, Maximum Likelihood (ML) estimation is not always possible, as explained in an introductory example. Thus, Generalized Least Squares (GLS) estimation is sometimes needed in order to estimate parameters. A subclass of power models is then considered in this paper: separable reduced-rank (SRR) models. They allow an optimal choice of weights for GLS estimation and simplifications in asymptotic studies concerning GLS estimators. Power 2 models belong to the subclass of SRR models and the asymptotic properties of GLS estimators are established. Similar results are also established for association models which are not SRR models. However, these results are more difficult to prove. Finally, 2 examples are considered to illustrate our results.     

灾后重建中社工组织多元角色的实践与实务模式选择

在灾后重建中,人们往往注重外界对灾民的各种帮助,却忽视促使灾民面对现实,比外界提供援助更为重要。因此,要通过充权等方法改变过去的“削权”而“增权”,减少灾民在社会结构中的弱势地位所造成的“习得的无助”,不仅促使灾民从“附属”到“自主”,更有利于整个灾区重建。在现代灾害越来越呈复合型特点的情况下,社工组织扮演的角色也越来越多元。社工组织在灾后重建中主要以直接或初级服务为主,面对案主在直接接触过程中达到服务目的,如团体工作、小区工作以及各种治疗、辅导、咨询等方法。     

Estimation and inference of combining quantile and least-square regressions with missing data

In this paper, we consider how to incorporate quantile information to improve estimator efficiency for regression model with missing covariates. We combine the quantile information with least-squares normal equations and construct an unbiased estimating equations (EEs). The lack of smoothness of the objective EEs is overcome by replacing them with smooth approximations. The maximum smoothed empirical likelihood (MSEL) estimators are established based on inverse probability weighted (IPW) smoothed EEs and their asymptotic properties are studied under some regular conditions. Moreover, we develop two novel testing procedures for the underlying model. The finite-sample performance of the proposed methodology is examined by simulation studies. A real example is used to illustrate our methods.     

Determinants of the demand for health screening in Malaysia: The case of the aged population

The increase in the prevalence of heart disease has become a serious public health issue. Hypercholesterolemia and hypertension are two main modifiable health risk factors for heart disease. In a fast ageing society, proper preventive measures should be adopted, particularly to achieve healthy aging. The objective of the present study is to examine the factors affecting the use of two health tests, namely blood cholesterol and blood pressure screenings among adults aged 60 years and above in Malaysia. Nationally representative data collected through the National Health and Morbidity Survey 2011 (NHMS, 2011) by the Ministry of Health, Malaysia were analysed. The survey used a two-stage stratified sampling method. Enumeration Blocks were selected in the first stage, while the second stage involved selection of Living Quarters. The proportions of those not using the blood cholesterol (45.4%) and blood pressure (30.8%) tests are alarmingly high. A bivariate probit model is applied to examine the determinants of the use of these two health screening tests. The results show that education, ethnicity, location of residence, employment status, health insurance and smoking significantly affect the decision of the aged population to undergo these tests. Key findings are, first, time is a more dominant factor than income in determining health screening behaviour among the aged population. Second, being covered by insurance increases the propensity to undergo health screening. Third, smokers have a lower likelihood of screening than non-smokers. The findings suggest that intervention programmes should be targeted at the less-educated, employed individuals, individuals not covered by health insurance and smokers.     

埃尔金建构主义的逻辑根基

埃尔金以"不当步骤"和"正确物"思想改造传统建构主义,并通过解释名称指称为之作出系统辩护。她强调诠释和理解在解释语言-世界之间关系中的作用,以此批判主流名称指称理论,并对指称概念进行扩充。埃尔金为其建构主义的辩护是不彻底的,但它道出了融合分析哲学和诠释学重构认识论的必要性。     

On multivariate nonlinear regression models with stationary correlated errors

In this paper we consider the statistical analysis of multivariate multiple nonlinear regression models with correlated errors, using Finite Fourier Transforms. Consistency and asymptotic normality of the weighted least squares estimates are established under various conditions on the regressor variables. These conditions involve different types of scalings, and the scaling factors are obtained explicitly for various types of nonlinear regression models including an interesting model which requires the estimation of unknown frequencies. The estimation of frequencies is a classical problem occurring in many areas like signal processing, environmental time series, astronomy and other areas of physical sciences. We illustrate our methodology using two real data sets taken from geophysics and environmental sciences. The data we consider from geophysics are polar motion (which is now widely known as “Chandlers Wobble”), where one has to estimate the drift parameters, the offset parameters and the two periodicities associated with elliptical motion. The data were first analyzed by Arato, Kolmogorov and Sinai who treat it as a bivariate time series satisfying a finite order time series model. They estimate the periodicities using the coefficients of the fitted models. Our analysis shows that the two dominant frequencies are 12 h and 410 days. The second example, we consider is the minimum/maximum monthly temperatures observed at the Antarctic Peninsula (Faraday/Vernadsky station). It is now widely believed that over the past 50 years there is a steady warming in this region, and if this is true, the warming has serious consequences on ecology, marine life, etc. as it can result in melting of ice shelves and glaciers. Our objective here is to estimate any existing temperature trend in the data, and we use the nonlinear regression methodology developed here to achieve that goal.     

Time series,point processes,and hybrids

Techniques developed for the study of time series, point processes, and marked point processes can suggest corresponding techniques for each other, and common techniques can be recognized. In this paper connections are drawn based on conceptual foundations, basic parameters, analyses, displays, algorithms, problems, models. The definitions and techniques are brought out by specific scientific problems. The emphasis is on the single-realization stationary case and on the use of second- and third-order moments to help understand the realization. The tool of stacking, at a particular period, is employed in several of the examples.     

西方管理理论中人性预设演变的逻辑进程——兼论企业文化管理产生的必然性

管理活动的展开以对人性的认识为前提,不同的管理理论及实践体现着不同的人性预设.文章分析了西方管理理论中的人性预设,阐明了几种主要的人性预设理论的逻辑关联及其演进的逻辑进程,并以此为出发点,探讨了企业文化理论产生的历史及其逻辑上的必然性.     

The Equivalence of Two Proportions Revisited

The classic conditional test for checking that the difference between two independent proportions is not null may not be appropriate in many circumstances. Dunnett & Gent (1977) showed that in clinical trials, in studies of drugs, etc, the aim is to prove the practical equality (equivalence) of both proportions. On other occasions the aim may be the opposite: i.e. to prove that the two proportions are substantially different (biologically significant). Both cases are usually solved by two one-sided tests (TOST test). In this article, this procedure is shown to be conservative and two true two-sided tests for each case are proposed.