课堂语言输入量对英语语言焦虑的影响

以增加课堂语言输入量可以降低语言焦虑为理论依据,在已经对英语082四个学期语言焦虑变化研究的基础上,调查了国贸082四个学期的语言焦虑变化情况,并且将两个班四个学期语言焦虑的变化做了横向比较,研究结果进一步表明,增加课堂语言输入量可以有效地降低学生的语言焦虑,但是课堂语言输入量必须达到阈值,按照本研究的结果,其阈值大概达到600～800课时数时,即可有效降低学生的语言焦虑。     

On a perturbed MAP risk model under a threshold dividend strategy

In this paper, we consider a perturbed risk model where the claims arrive according to a Markovian arrival process (MAP) under a threshold dividend strategy. We derive the integro-differential equations for the Gerber–Shiu expected discounted penalty function and the moments of total dividend payments until ruin, obtain the analytical solutions to these equations, and give numerical examples to illustrate our main results. We also get a matrix renewal equation for the Gerber–Shiu function, and present some asymptotic formulas for the Gerber–Shiu function when the claim size distributions are heavy-tailed.     

The Social Model of Disability as a Threshold Concept: Troublesome Knowledge and Liminal Spaces in Social Work Education

This paper draws on the notion of threshold concepts to consider the way in which disability studies has the capacity to transform social work students' understandings of disability and therefore influence their practice. Most students enter social work programmes with the professed aim of ‘helping’ and so to be confronted by an approach (the social model of disability) and a body of research and theorising (disability studies) that challenges their taken-for-granted assumption that social work practice is ‘helpful’ is unsettling and can lead to resistance. The purpose of this article is to interrogate practice on a social work programme where a commitment to social model practice is explicated and embedded with the purpose of identifying what it is we want students to ‘get’, whether they find this troubling and how they can be effectively supported as they move through liminal spaces in social work education.     

Power periodic threshold GARCH model: Structure and estimation

Abstract

In this paper, we introduce and study the Power Periodic Threshold GARCH Model (PPTGARCH). We give the necessary and sufficient conditions for the existence of the unique strictly periodically stationary solution of the model and the necessary and sufficient conditions for the existence of moments. A sufficient condition for the periodic geometric ergodicity and β – mixing property using the uniform countable additivity condition is given. We prove the consistency and asymptotic normality of the Quasi-Maximum Likelihood estimator (QMLE) of the parameters. Simulation studies to illustrate consistency and asymptotic normality of the estimators for different underlying error distributions are presented.     

Parameter and quantile estimation for the three-parameter gamma distribution based on statistics invariant to unknown location

The three-parameter gamma distribution is widely used as a model for distributions of life spans, reaction times, and for other types of skewed data. In this paper, we propose an efficient method of estimation for the parameters and quantiles of the three-parameter gamma distribution, which avoids the problem of unbounded likelihood, based on statistics invariant to unknown location. Through a Monte Carlo simulation study, we then show that the proposed method performs well compared to other prominent methods in terms of bias and mean squared error. Finally, we present two illustrative examples.     

On a threshold representation for complex load-sharing systems

Complex load-sharing systems are studied to incorporate dependencies among components through a load-sharing rule. As the load on the system increases, a series of cycles of Phase I/II failures occur where Phase I failure is a single component failure, which then causes a cascade of component failures (Phase II) due to the load transfer as these components fail. A threshold representation for the process of system failure is given. This representation is a gamma-type mixture representation when the component strengths are independent exponentials. In this case, for a given breaking pattern the mixture is over the gamma scale parameter and is based on a convolution of uniforms defined by the load-sharing parameters. Such convolutions can be approximated by normal densities which reduces the dimension of the parameter space. This representation can be generalized to independent component strengths with arbitrary distributions by transforming the strength and load-sharing to pseudo-strength and pseudo-load-sharing rules.     

细胞兴奋在模拟电路中的应用探析

通过简述细胞兴奋的过程及现象，讨论细胞兴奋现象的几个主要特点：阈刺激、“全或无”现象及不应期与相关电路特点的相似性，设计了细胞兴奋的模拟原理电路     

试论儒家文化对我国人口与计划生育的影响

本文本着批判继承祖国文化遗产的宗旨 ,以《四书五经》及儒家其他书籍为研究对象 ,重点探讨和分析了儒家文化对我国人口与计划生育产生的正负面影响 ,并提出了消除其负面影响的相应对策     

产业结构升级对城乡收入差距的门槛效应分析

综合借鉴前人的研究成果,本文将产业结构升级、城镇化进程和城乡收入差距三者联系起来,初步判断产业结构升级对城乡收入差距的影响是非线性的;然后采用2005-2018年我国省级面板数据,以城镇化率为门槛变量,对此进行了实证检验。结果显示:产业结构升级与城乡收入差距之间存在明显的非线性关系,前者对后者的影响具有显著的双门槛效应,当城镇化水平处于初级阶段时,产业结构合理化和高级化扩大了城乡收入差距;当城镇化水平越过第一门槛值进入中级阶段后,产业结构合理化的影响减弱为不显著,而产业结构高级化仍在显著扩大城乡收入差距;当城镇化水平越过第二门槛值进入高级阶段后,产业结构合理化和高级化都表现为显著缩小城乡收入差距。通过剔除样本中的极端值、替换被解释变量和核心解释变量的代理变量,进行稳健性检验,上述结论依然成立。另外,分地区来看,东部、东北和西部地区的产业结构升级对城乡收入差距的影响同样存在显著的双门槛效应,但不同区域的表现不尽相同,东部和东北地区的门槛效应均表现为倒“U”型;西部地区则“慢半拍”,尚处于倒“U”型曲线的左侧;中部地区则仅存在以城镇化率为门槛变量的单门槛效应。文章分析了其中的原 因,并给出了政策含义。