Inference for the Generalized Normal Laplace Distribution

The generalized normal Laplace distribution has been used in financial modeling because of its skewness and excess kurtosis. To estimate its parameters, we use a method based on minimizing the quadratic distance between the real and imaginary parts of the empirical and theoretical characteristic functions. The quadratic distance estimator (QDE) obtained is shown to be robust, consistent, and with an asymptotically normal distribution. The goodness-of-fit test statistics presented follow an asymptotic chi-square distribution. The performance of the QDE is illustrated by simulation results and an application to financial data.     

Testing for pairwise serial independence via the empirical distribution function

Built on Skaug and Tjøstheim's approach, this paper proposes a new test for serial independence by comparing the pairwise empirical distribution functions of a time series with the products of its marginals for various lags, where the number of lags increases with the sample size and different lags are assigned different weights. Typically, the more recent information receives a larger weight. The test has some appealing attributes. It is consistent against all pairwise dependences and is powerful against alternatives whose dependence decays to zero as the lag increases. Although the test statistic is a weighted sum of degenerate Cramér–von Mises statistics, it has a null asymptotic N (0, 1) distribution. The test statistic and its limit distribution are invariant to any order preserving transformation. The test applies to time series whose distributions can be discrete or continuous, with possibly infinite moments. Finally, the test statistic only involves ranking the observations and is computationally simple. It has the advantage of avoiding smoothed nonparametric estimation. A simulation experiment is conducted to study the finite sample performance of the proposed test in comparison with some related tests.     

Multivariate Linear Regression Model with Elliptically Contoured Distributed Errors and Monotone Missing Dependent Variables

In this article, the multivariate linear regression model is studied under the assumptions that the error term of this model is described by the elliptically contoured distribution and the observations on the response variables are of a monotone missing pattern. It is primarily concerned with estimation of the model parameters, as well as with the development of the likelihood ratio test in order to examine the existence of linear constraints on the regression coefficients. An illustrative example is presented for the explanation of the results.     

关键期假说与儿童第二语言学习

第二语言关键期是否绝对存在学界尚未形成定论，国内上有大量学者从不同角度研究证明或反证明了这一假说的存在，但是反对派的观点并未否认儿童学习第二语言的种种优势；同时，通过与成人的比较也可说明儿童学习第二语言的优势所在，从而得出儿童学习第二语言完全可行的结论。     

On hypothesis testing for Poisson processes. Singular cases

ABSTRACT

We consider the problem of hypothesis testing in the situation where the first hypothesis is simple and the second one is local one-sided composite. Wedescribe the choice of the thresholds and the power functions of different tests when the intensity function of the observed inhomogeneous Poisson process has two different types of singularity: cusp and discontinuity. The asymptotic results are illustrated by numerical simulations.     

输出假设理论对促进中介语发展的实践指导

在分析大学生英语课堂学习特点与大学生中介语发展障碍的成因的基础上,指出可理解语言输出在二语习得中扮演着重要角色,传统重输入轻输出的外语教学模式不利于中介语发展,缺乏语言输出成为中介语发展的瓶颈.将输出假设理论应用于课堂教学的实践表明,在抓住课堂教学关键期、增加输入有效性的前提下,减少学生对规避学习策略的依赖,创设元语言环境,鼓励有效的语言输出,以输出性活动提升学生对自身中介语系统的关注,有利于提高教学效果.     

Moving the Boundaries of Feminist Social Work Education with Disabled People in the Neoliberal Era

Until recently social work education in Australia has either marginalised or neglected disability by omission. Given the increasing number of disabled people in the community, the teaching of social work within a disability studies emancipatory paradigm as an essential part of the curriculum is long overdue. As many social work educators have suggested, we are at a critical moment in Australia, where the policy environment in which social work is embedded has largely been reframed in line with neoliberal trends. For disabled people, this has meant an ongoing state campaign to diminish disability entitlements, from decreasing disability social security regimes through to the rationalisation of adult disability support and care schemes. Social workers are negotiating the competing demands of these policy constraints alongside the needs of the disabled people they work with. New moral dilemmas have emerged where they are actively faced with the question of ‘who to serve?’.     

Pre-checking for non-monotonicity of the Wald statistic

The non-monotonic behaviour of the Wald test in some finite-sample applications leads to low power when the null hypothesis needs rejection most. This article proposes a simple check for discerning if the Wald statistic for testing significance of regression coefficients is non-monotonic in the neighbourhood of the parameter space from which the sample data are drawn. Monte Carlo simulations show that this method works rather well for detecting situations where the Wald test can be safely applied. An example is provided to illustrate the use of this check.     

重温"语言相对论"

"语言相对论"是关于语言、文化和思维三者关系的重要理论,即不同文化的语言具有结构、意义和使用等方面的差异,人类的思维行为与这些差异有关,程度不同地受其影响和制约.该理论最杰出代表是20世纪上半叶的"萨丕尔-沃尔夫假设".由于该"假设"局限于语法结构的差异,所以曾一度遭受到批判和冷遇.然而,随着语言使用研究的深入,它的理论基础及其活力得到加强,理论意义也得以进一步彰显.     

南方三岁以下幼儿汉语声调习得研究

基于一名长沙汉语幼儿的长期跟踪研究,旨在探讨南方三岁以下汉语幼儿何时掌握汉语四声调,其声调习得顺序以及声调发展的过程。结果表明：尽管该幼儿在两岁时区分汉语阳平和上声时存在部分困难,但她已经基本掌握了汉语四个声调,可较为准确地进行产出。随着年龄的增长,与母语接触相应增多,该幼儿产出的声调特征不断向母语靠近,体现了母语的影响。研究结果支持了早期交互假设,不支持独立假设。