考虑成分股联跳与宏观信息发布的沪深300指数已实现波动率模型研究

利用日内高频数据计算的已实现波动率较好度量了金融资产的风险,因此对其预测模型的研究具有重要意义。考虑到指数成分股的联跳可能蕴含指数跳跃所未能反映的信息,提出运用非参数方法识别指数成分股的联跳,采用自回归条件风险模型估计成分股联跳强度,并将其引入指数的已实现波动率异质自回归（HAR-RV-CJ）模型中,分析模型预测性能的改进。进一步的,考虑到宏观信息公告的发布可能对股市产生整体性影响,相应影响成分股联跳的几率;因此,在成分股联跳的自回归条件风险模型中引入居民消费价格指数、国内生产总值、贸易差额等宏观信息公告变量,并分析对联跳强度估计以及指数已实现波动率预测的影响。采用2011年1月4日至2013年7月11日沪深300指数及其成分股高频数据的实证表明,指数成分股联跳与指数跳跃具有不同的特征;用成分股联跳强度代替HAR-RV-CJ模型中的跳跃构建的HAR-RV-CI模型,较原始的HAR-RV-CJ模型,以及同时考虑指数跳跃与成分股联跳强度的HAR-RV-CJI模型,具有明显较优的样本内拟合与样本外预测性能。引入宏观信息公告变量可以改进联跳强度自回归条件风险模型的拟合效果,并提高指数已实现波动率模型的样本内拟合能力,但对于指数已实现波动率的样本外预测性能并无明显的帮助。     

Pair‐copula constructions for non‐Gaussian DAG models

We propose a new type of multivariate statistical model that permits non‐Gaussian distributions as well as the inclusion of conditional independence assumptions specified by a directed acyclic graph. These models feature a specific factorisation of the likelihood that is based on pair‐copula constructions and hence involves only univariate distributions and bivariate copulas, of which some may be conditional. We demonstrate maximum‐likelihood estimation of the parameters of such models and compare them to various competing models from the literature. A simulation study investigates the effects of model misspecification and highlights the need for non‐Gaussian conditional independence models. The proposed methods are finally applied to modeling financial return data. The Canadian Journal of Statistics 40: 86–109; 2012 © 2012 Statistical Society of Canada     

An Analysis of Verbal Stimulus Control in Intraverbal Behavior: Implications for Practice and Applied Research

A common characteristic of the language deficits experienced by children with autism (and other developmental disorders) is their failure to acquire a complex intraverbal repertoire. The difficulties with learning intraverbal behaviors may, in part, be related to the fact that the stimulus control for such behaviors usually involves highly complex verbal stimuli. The antecedent verbal control of intraverbal behavior may involve discriminative stimuli (i.e., discriminated operants), conditional stimulus control, and/or control by compound stimuli. Distinctions among these different types of antecedent control are presented, along with recommendations for intervention procedures that may facilitate the acquisition of intraverbal behavior.     

未成年人刑事案件附条件不起诉制度的理论和实践

附条件不起诉作为我国近年来积极推行的司法改革制度,体现了宽严相济刑事政策、起诉便宜主义、和谐社会理念,具有良好的法律效果和社会效果。修订后的刑事诉讼法对该制度进行明文规定,完善了我国的不起诉制度体系,也必将导致附条件不起诉的全面实施。     

上市公司现金流操控动机选择研究

对现金流管理的研究是继盈余管理后兴起的管理层舞弊行为研究。在已有关于现金流操控阈值点研究的基础上,以2004年至2009年有分析师预测值的中国上市公司为样本,运用条件分布法,采用统计变量τ和z计算分布频率,并以分布频率直方图直观显示,分析上市公司在现金流量阈值点操控行为的动机选择。从统计结果和分布频率图可知,公司管理层对3个现金流阈值点确实存在不同选择。操控现金流微正的动机最强,即公司管理层更注重报告微正现金流量,其次是超越往年现金流量动机,而迎合分析师预测的动机最弱。研究还发现,管理层存在多重操控动机,即在控制已达到某一个阈值点之后,公司管理层更倾向达到另一个阈值点,存在好上加好的心理。     

模糊概率决策系统的属性约简

基于模糊等价关系及论域上的概率分布建立模糊概率信息系统,并给出了模糊概率信息系统的熵与条件熵.最后基于模糊概率信息系统的条件熵提出模糊概率决策信息系统的属性约简并给出了算法.     

Conditional intensity: A powerful tool for modelling and analysing point process data

The conditional intensity function of a spatial point process describes how the probability that a point of the process occurs ‘at’ a particular point in its carrier space depends on the realisation of the process in the remainder of the carrier space. Provided that the point process is simple, the conditional intensity determines all of the properties of the process, in particular its likelihood function. In this paper, we review the use of the conditional intensity function in the formulation of point process models and in making inferences from point process data, giving separate consideration to temporal, spatial and spatiotemporal settings. We argue that the conditional intensity function should take centre-stage in spatiotemporal point process modelling and analysis.     

Conditionally Reducible Natural Exponential Families and Enriched Conjugate Priors

Consider a standard conjugate family of prior distributions for a vector-parameter indexing an exponential family. Two distinct model parameterizations may well lead to standard conjugate families which are not consistent, i.e. one family cannot be derived from the other by the usual change-of-variable technique. This raises the problem of finding suitable parameterizations that may lead to enriched conjugate families which are more flexible than the traditional ones. The previous remark motivates the definition of a new property for an exponential family, named conditional reducibility. Features of conditionally-reducible natural exponential families are investigated thoroughly. In particular, we relate this new property to the notion of cut, and show that conditionally-reducible families admit a reparameterization in terms of a vector having likelihood-independent components. A general methodology to obtain enriched conjugate distributions for conditionally-reducible families is described in detail, generalizing previous works and more recent contributions in the area. The theory is illustrated with reference to natural exponential families having simple quadratic variance function.     

股市预警系统与构成指标简述

中国股市是一个高风险的股市 ,因此有必要运用现代金融计算技术和计量金融理论建立一套股市预警系统。本文在讨论了建立股市预警系统的必要性、可行性的基础上 ,着重讨论了股市预警系统的指标构成原则和框架 ,将近年来在现代金融理论中发展很快的协整理论(CointegrationTheory)、条件异方差理论、市场有效性理论等引入到股市预警系统框架中来