金融时间序列变点探测的小波模极大值线方法

研究小波变换方法在金融时序分析中模型变点探测的应用,对金融时间序列采用连续小波变换,通过分析小波变换模极大值线对应的时间序列样本点的小波系数特点,提出了金融时间序列变点探测的小波模极大值线方法,并对广义自回归条件异方差均值模型(GARCH-M模型)进行了仿真计算,其结果验证了此方法的实用性和有效性.该方法更能准确定位金融资产收益率波动所发生的具体时刻,有利于金融资产价格异常时点的正确识别与统计建模分析和资产收益率波动的预测.     

基于GARCH-VaR模型的石油价格风险研究

石油价格收益率一般不符合VaR模型的独立、对称的正态分布假设,表现出金融时间序列的非对称性、异方差、波动聚集等特征.文章提出利用GARCH模型估计石油价格收益率的时变条件方差,改进传统VaR对方差的估计,并通过实证分析,估计石油价格风险,即在一定的置信度水平下石油价格可能的最大日损失值,估计结果显示改进的GARCH-V...     

GARCH模型的实证研究

本文通过对上证综指收益率序列的实证分析,发现其具有明显的群集聚集性、波动性、尖峰厚尾的特征,并应用GARCH及其扩展模型对该序列进行建模分析,发现GARCH模型可以较好的消除金融时间序列的异方差性,同时发现,GARCH-t的拟合效果更好一些。     

ARCH模型在金融时间序列中的拟合应用

讨论了自回归条件异方差(Autoregressive Conditional Heteroskedastic,简称ARCH)模型在金融时间序列分析中的拟合应用,以一金融时间序列为例,通过SAS/ETS中的自回归(Autoreh)过程实现对该金融时间序列的自回归-广义自回归条件异方差(Autoregressive-generalzed ARCH,简称AR-GARCH)模型的拟合和分析,最终得到理想结果.     

CARCH模型在上证指数收益率分析中的应用

本文运用Engle的ARCH法对上证指数收益率的异方差性进行了详细的分析,得出涨跌幅制制度的实施对收益率的异方差性有明显的影响,序列异方差性与序列长度存在密切的关系.在运用CARCH模型对序列进行拟合时,发现拟合模型的阶数与序列长度也存在一定的关系.     

证券投资基金市场的ARMA-ARCH类模型分析

文章通过分析自回归条件异方差(ARCH)类模型的统计结构,讨论了ARCH模型族的拟合波动性的优缺点,建立了ARMA-ARCH类模型,并用平稳帕雷托分布代替标准正态分布;以中信基金管理有限公司的股票基金与债券基金指数的收盘价为样本,对我国基金市场收益率分布用ARMA-ARCH类模型进行实证分析,解决了方差时变条件下金融波动时间序列建模问题,描述了基金序列的特性。     

基于GED的混合ARCH模型

提出了基于广义误差分布的混合自回归条件异"方差"模型,将时间序列尾部的特征融入到混合条件异"方差"模型的参数估计之中,发现模型中的指标r和数据本身尾部厚薄的性质有关.给出了该模型参数估计的EM算法,并利用BIC准则对模型进行定阶.     

半参数方法对上证指数波动率的预测分析

根据金融时间序列一般都存在条件异方差性,本文研究了两种半参数时间序列模型的估计方法,通过实际算例对参数模型与半参数模型,以及不同的半参数模型在金融时间序列的拟合与波动率预测方面的表现作了比较。结果表明,半参数模型要优于参数模型,半参数可加模型要优于多项式样条估计模型。      

棉花期货价格波动率分析

针对棉花已成为制约“十四五”规划中纺织行业发展不可或缺的关键因素这一事实,提出通过研究棉花期货价格的波动来体现纺织业成本变化。 基于 2008 年 1 月 2 日到 2021 年 9 月 6 日棉花 CF999 期货价格数据时序图,得到原序列不平稳的结论,处理后得棉花期货价格收益率序列,由 J-B 统计量、ADF 检验 统计量,得到棉花期货价格收益率序列是平稳时间序列,但不服从正态分布,有尖峰厚尾和高阶异方差性的统计特征;然后考虑收益率序列服从 T 分布和广义误差(GED)分布,分别构建 GARCH 类模型,具体利用GARCH、GARCH-M、EGARCH 和 MS-GARCH 4 种模型对棉花价格波动特征进行研究,结果表明:基于 T 分布 的模型比 GED 分布更能描述棉花期货价格收益率序列的波动特征;棉花市场不是“高风险、高回报”产业;收益率序列存在反杠杆效应;MS(3)-GARCH(1,1)模型的拟合效果最优,收益率序列有体制变换现象,各种波动的持续期不同,高波动状态最短,为 2. 12 d;最后提出相关建议。     

EGARCH模型和分位数自回归类模型在风险预测中的比较

利用了三种时间序列模型对中美汇率的风险进行一步向前滚动预测。1)EGARCH模型,它可以刻画金融资产收益率的尖峰厚尾现象,异方差性,波动集聚性和杠杆效应。2)非常适合具有异方差性的QAR模型,该模型不需要假定误差项的分布,可以很好地刻画条件异质性,在模拟具有尖峰厚尾的金融数据时,得到了广泛的应用。3)T-QAR模型,该模型可以通过门限变量控制分段线性函数,进而刻画金融资产具有的非线性性和非对称性。最后,对三种模型的预测效果进行了VaR回溯检验,结论是T-QAR模型的预测效果最佳,而EGARCH模型的预测效果最差。     

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.     

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     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

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     

Journal of Donghua University ( English Edition) Contents of Volume 31

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