LOG-PERIODOGRAM ESTIMATION OF LONG MEMORY VOLATILITY DEPENDENCIES WITH CONDITIONALLY HEAVY TAILED RETURNS

Many recent papers have used semiparametric methods, especially the log-periodogram regression, to detect and estimate long memory in the volatility of asset returns. In these papers, the volatility is proxied by measures such as squared, log-squared, and absolute returns. While the evidence for the existence of long memory is strong using any of these measures, the actual long memory parameter estimates can be sensitive to which measure is used. In Monte-Carlo simulations, I find that if the data is conditionally leptokurtic, the log-periodogram regression estimator using squared returns has a large downward bias, which is avoided by using other volatility measures. In United States stock return data, I find that squared returns give much lower estimates of the long memory parameter than the alternative volatility measures, which is consistent with the simulation results. I conclude that researchers should avoid using the squared returns in the semiparametric estimation of long memory volatility dependencies.     

刘熙载楚辞学的研究方法

刘熙载在研究楚辞时,运用了以意逆志法、多重比较法、举借概括法等方法,从而形成了一套颇具特色的文学批评法。     

Social identities and political cleavages: the role of political context

Summary. Using a novel method, the paper investigates the influence of social group identities on attitudes and on voting in a variety of political contexts. Examining the major regions of Britain, Canada and the USA, we find considerable national and regional diversity in the nature of social cleavages. For example, social class and race had widely different effects across societies, but within societies their effects on attitudes and on voting were very similar. However, despite that, age and religion had a similar effect on attitudes across societies; the effects on voting varied considerably. The significant within-country differences underline the importance of using region, rather than country, as the unit of analysis. More importantly, these results highlight the role of political context, especially competing cleavages and the structure of party competition, in the establishment of politically relevant social cleavages.     

Narrating Significant Experience: Reflective Accounts and the Production of (Self) Knowledge

Notwithstanding the rise of evidence-based practice, other tendencieswithin social work scholarship are also discernible. One ofthese is the study of the everyday, routine accomplishment ofpractice, drawing on microsociological methods and techniques.In this article, I apply techniques drawn from narrative anddiscourse analysis to the study of reflective practice accounts,which hold an important place in social work education. In particular,it is relevant to examine the form that reflective accountstake and the rhetorical and narrative devices deployed withinthem to accomplish a competent professional identity. My argumentis not that such accounts of practice are untruthful, ratherI propose that we would do well to move beyond taking texts(and talk) for granted and treating language as merely the mediumfor expressing inner thoughts and feelings. Social work shouldtake seriously the need to explore its modes of representationand to cultivate a more self-conscious approach to the way professionaland client identities are produced in practice.     

L'Intervention Sociologique After Twenty-Five Years: Can It Translate into English?

The sociological intervention is a research method developed in France by Alain Touraine in 1976 to explore social movement action. Since then it has undergone significant development, both in terms of the type of social experience explored and the broader research program framing it. Despite its importance, the intervention remains little known and virtually untested within English-language sociology. This article examines key dimensions of this research method through discussing several examples, and argues that the intervention has much to offer English-language sociologists concerned with questions of agency and reflexivity, relationship, narrative and experience.     

从韩国人学汉语看对零起点学生的对外汉语教学

在来华学习汉语的留学生中,有一部分是处于零起点阶段的韩国留学生。在教学过程中不仅要利用各种形象化的技巧跨越因语言不通而形成的学习障碍,还要注重基础内容的学习,要使其认识到汉韩文化和语言的相通及差异。     

构建服务型政府行政文化模式探索

阐明了服务型政府行政文化模式的内涵、特点，提出了构建服务型政府行政文化模式的途径。     

Sample selection in radiocarbon dating

Archaeologists working on the island of O'ahu, Hawai'i, use radiocarbon dating of samples of organic matter found trapped in fish-pond sediments to help them to learn about the chronology of the construction and use of the aquicultural systems created by the Polynesians. At one particular site, Loko Kuwili, 25 organic samples were obtained and funds were available to date an initial nine. However, on calibration to the calendar scale, the radiocarbon determinations provided date estimates that had very large variances. As a result, major issues of chronology remained unresolved and the archaeologists were faced with the prospect of another expensive programme of radiocarbon dating. This paper presents results of research that tackles the problems associated with selecting samples from those which are still available. Building on considerable recent research that utilizes Markov chain Monte Carlo methods to aid archaeologists in their radiocarbon calibration and interpretation, we adopt the standard Bayesian framework of risk functions, which allows us to assess the optimal samples to be sent for dating. Although rather computer intensive, our algorithms are simple to implement within the Bayesian radiocarbon framework that is already in place and produce results that are capable of direct interpretation by the archaeologists. By dating just three more samples from Loko Kuwili the expected variance on the date of greatest interest could be substantially reduced.     

The Assessment of Probability Distributions from Expert Opinions with an Application to Seismic Fragility Curves

A method is developed for estimating a probability distribution using estimates of its percentiles provided by experts. The analyst's judgment concerning the credibility of these expert opinions is quantified in the likelihood function of Bayes'Theorem. The model considers explicitly the random variability of each expert estimate, the dependencies among the estimates of each expert, the dependencies among experts, and potential systematic biases. The relation between the results of the formal methods of this paper and methods used in practice is explored. A series of sensitivity studies provides insights into the significance of the parameters of the model. The methodology is applied to the problem of estimation of seismic fragility curves (i.e., the conditional probability of equipment failure given a seismically induced stress).     

系统法在课程教学改革中的应用研究

本文以系统方法为指导,就日语专业《高级日语》课从明确教学目标和要求、做好授课前的准备工作、注重课堂教学方法的针对性使用、开展有效的课外活动等四个环节试作论述。