用ARCH模型研究中国股市的波动特征

中国股市的波动特征是学者们和投资者关注的一个重要领域,与国外成熟的证券市场相比,中国股票市场作为新兴市场,具有其特有的性质,如更高的不可预测性和复杂性,股票价格更大的波动幅度和频率.研究中国股市的波动特征就具有重要的理论价值和现实价值.投资者在选股过程中需要理解中国股市随时间变化的波动情形,而ARCH模型族正是研究股市波动随时间变化的工具.以上证综合指数为对象,采用GARCH类模型对中国股市波动情况进行实证研究,为股市收益的尖峰厚尾特点、波动的集簇性、时变性提供了实证证据,并对实证结果作了一些初步的探讨.     

基于GARCH模型的上证指数实证分析

在对GARCH模型进行探究的基础上,针对上证指数收益率的波动特征进行GARCH建模,最后通过对所得模型结果的分析得出了我国股市与其他发达国家的股市具有一些共同的地方,即我国的上证指数收益率序列具有显著的异方差特征,且收益率波动的大小与其自身过去的波动大小有非常明显的关系,因此说我国的大盘指数也可以采用GARCH模型来进行拟合和解释。     

沪深股市的波动性分析——基于t分布下GARCH和SV模型的比较

构建基于N分布和t分布下的GARCH(1,1)和SV模型,并通过实证分析探讨了上证指数和深证成指收益序列的波动性.分析结果表明,GARCH(1,1)类模型和SV类模型能较好地拟合沪深股市收益率的波动,并指出我国股市存在较强的波动持续性;而基于t分布的各模型能有效地刻画股市的厚尾性;此外,通过计算VaR值,说明深市比沪市的风险更大,且SV类模型能更准确地反映收益率的风险特性.     

MDH理论与日历效应下的中国股市量价关系

基于分布混合假说(MDH)理论的数学推导,以我国深沪股市的大盘指数为研究对象,检验原始交易量、包含自相关性的交易量对广义自回归条件异方差模型(GARCH)效应的解释效果,并分析日历效应对交易量与股价波动性关系的特殊影响.结果表明,GARCH模型可以很好地拟合中国股市的股价波动持续性问题;当引入原始交易量以后,股价波动性在一定程度上可以为原始交易量所解释,而包含自相关性的交易量对股市GARCH效应并无很好的解释力.经实证分析证实,股价的日历效应对于上海市场中交易量对股价波动性的解释有着推波助澜的作用.     

基于GARCH类模型的中国股市收益率分析

自二十世纪八十年代以来, 金融时间序列的波动群聚性,尖峰厚尾性和长记忆性特征的研究已经成为众多研究的论题, 是当今金融风险管理的核心. GARCH类模型是波动群聚性建模中常用的模型. 作者在简要介绍金融时间序列波动性的GARCH模型的基础上, 运用MATLAB软件包编程, 利用FIGARCH模型、NAGARCH模型和EGARCH模型对中国股市波动特征进行建模, 并比较了正态分布、Studentt分布、GED分布和偏t分布等四种不同分布特征的FIGARCH、NAGARCH和EGARCH模型对中国股市波动特征的拟合.实证结果表明, 偏t分布更适合我国股市波动特征的描述, FIGARCH模型在拟合效果方面要优于其他模型.     

中国股市收益波动的实证研究

采用GARCH类模型，利用上证综合指数对中国股市收益波动进行了实证研究。以前的研究显示中国股市波动存在反向的不对称性或不对称性不显著，并归因于中国股市的高投机性。而本研究的TARCH模型和EGARCH模型的实证结果首次提出了新的不同证据。说明中国股市存在显著的不对称性。对杠杆效应和波动反馈效应在中国股市的作用进行理论分析，认为波动反馈效应更能说明中国股市波动的不对称性。     

基于广义可加模型的波动率估计方法

放宽了传统GARCH模型参数形式的假定,将广义可加模型引入条件方差的估计,改进了[Bhlmann P,McNeil A J.An algorithm for nonparametric GARCH modelling.Computational Statisticsand Data Analysis,2002,40(4):665-683]提出的迭代算法并将其用于可加GARCH模型的估计.通过能够控制真实波动率的数学模拟实验,分别用样本内和样本外估计的方法说明了可加GARCH模型在估计现有参数模型无法刻画的复杂序列波动率时具有更好的估计效果,而与非参数模型相比,可加GARCH模型也有较好的估计效果.通过一个推断波动特征的算例,表明了可加GARCH模型对研究新兴市场股市或者处于金融危机中的股市等存在复杂波动特征的金融市场波动率有着非常现实的意义.     

后危机时代中国股市波动性解析:基于GARCH模型族研究

波动性是衡量股市风险和稳定的重要指标之一,对股市的健康发展具有重要影响。文章以上证指数为研究标的,利用GARCH族模型对股市的波动性进行了比较研究。结果表明,后危机时代,中国股市收益率波动确实存在非对称现象,EGARCH模型比TGARCH模型更能适合刻画中国股市的特征,但GARCH模型族存在伪持续,尚待改进。     

基于SSRM的上海证券市场波动性研究

分别对上海证券市场的商业、地产等4个行业板块进行建模,讨论了它们在简单体制转换模型下的波动特征,并计算了各个行业板块的VaR.研究表明:4个行业板块的波动率过程存在明显的体制转换特征,转换概率较高;不同行业板块间的风险有所差别,但简单体制转换模型明显低估了我国股市的风险水平.     

上证综指收益率波动性的非线性方法研究

以上证综指日收盘价为样本建立了对上证综指收益率波动性的非线性模型.实证结果表明我国上海股市的价格波动具有异方差性及显著的左尖峰厚尾的特征;收益率的波动不服从正态分布;具有集聚性和记忆性;波动持续时间较长.通过分析比较GARCH模型拟合效果较好,并预测结果有一定的稳定性.同时对收益率建立了EGARCH（1,1）和TARCH（1,1）模型,表明收益率波动存在一定的杠杆效应.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with