一类新的损失函数下负二项分布模型的Bayes可靠性分析

在一类新的加权平方损失函数下,给出了负二项分布可靠度的Bayes和多层Bayes估计,并利用E Bayes方法给出了负二项分布可靠度的E Bayes估计.针对得到的3种估计,给出了数值模拟,结果表明:E Bayes估计比多层Bayes估计优良.     

INAR(1)模型参数的Bayes估计

利用Bayes方法研究INAR(1)模型的参数估计, 给出了模型参数的Bayes估计因子, 并通过数值模拟将Bayes估计与Yule Walker估计、 条件最小二乘估计、 条件极大似然估计进行比较. 结果表明, Bayes估计方法在一定情形下优于其他方法.     

熵损失下随机截尾情形指数分布参数的Bayes估计

为解决指数分布在熵损失函数和随机截尾数据下的参数估计问题,采用理论分析和随机模拟试验的方法,推导了参数在任意先验分布下的Bayes估计和伽玛共轭先验分布下具体的Bayes估计和多层Bayes估计,利用Monte Carlo方法对估计进行了计算,随机模拟试验对MLE、Bayes估计和多层Bayes估计进行了对比分析.研究结果表明,熵损失函数下的估计具有较高精度,多层Bayes估计稳健性较好.研究结论丰富了指数分布的Bayes统计分析,研究方法有助于熵损失函数下其它寿命分布的参数估计.     

熵损失下失效率的E-Bayes估计及其性质

失效率的多层Bayes估计需要用到复杂的积分,计算比较困难.本文提出了一种新的估计方法——E-Bayes估计法.它是在Bayes估计的基础上,先给出超参数的先验分布,进而对失效率进行估计.文章分别给出了在特定超参数先验分布的条件下,失效率的E-Bayes估计和多层Bayes估计的计算公式.结果表明,失效率的E-Bayes估计避免了多层Bayes估计复杂的积分计算,形式上更加简洁,便于计算.并通过实例证明,对于同一组实验数据,失效率的E-Bayes估计和多层Bayes估计的数值计算结果十分接近.这说明,失效率的E-Bayes估计不仅具有多层Bayes估计的稳健性,而且具有多层Bayes估计的精确性,从而表明本文提出的失效率的E-Bayes估计法是可行的,且相比于失效率的多层Bayes估计更加简洁,更便于应用.     

基于Bayes估计的有限元模型修正

讨论了基于Bayes方法来修正有限元动力模型问题 ,给出了利用Bayes方法估计参数的公式 .根据Bayes估计结果 ,应用矩阵逆特征值理论 ,提出了有限元模型修正方法 .最后用一个数值试验说明了该方法的有效性 .     

对称损失下二项分布参数的Bayes估计问题

在对称损失函数下,利用共轭先验分布讨论二项分布参数P的Bayes估计、多层Bayes估计及E-Bayes估计,并证明该参数的Bayes估计是可容许的.最后给出关于Bayes估计、多层Bayes估计及E-Bayes估计的数值模拟,并比较了三者之间的优良性.     

先验信息有偏时Bayes估计的PPC优良性条件

Bayes估计在对测量数据进行处理时,充分利用了参数的先验信息和适时的观测信息.在先验信息正确的前提下,Bayes估计相对于LS估计具有Posterior Pitman Closenes即PPC优良性.然而,在许多情况下,先验信息具有主观性,不可避免地存在偏差.利用有偏的先验信息得到的Bayes估计可能不具有这种优良性,为此,给出了这种情况下Bayes估计具有PPC优良性的一个充要条件.鉴于一般情况下先验的精确分布是未知的,用实例给出了一种选取先验方差的方法,用这种方法得到的Bayes估计具有PPC优良性.     

指数分布恒加试验定时截尾试验数据缺失时的Bayes分析

运用Gibbs抽样迭代方法,解决Bayes分析中的后验边际分布的计算问题,得到满足顺序约束的参数的Bayes估计.通过Monte-Carlo模拟表明,在各场合存在先验信息的情况下,Bayes估计的相对偏差和相对均方误差都小于极大似然估计;而对于没有先验信息的情况,Bayes估计跟极大似然估计的效果差不多.     

空间自回归模型中参数的Bayes估计

首先采用线性Bayes方法估计了空间自回归模型的参数,并在均方误差矩阵准则下研究了线性Bayes估计相对两步最小二乘估计的优良性.然后,使用Metropolis抽样算法实现了对空间自相关系数的估计.最后,通过模拟试验比较了线性Bayes估计与两步最小二乘估计的优缺点.     

两参数广义指数分布族形状参数的经验Bayes估计

利用经验Bayes方法研究了两参数广义指数分布未知形状参数的Bayes估计,并给出了数值模拟例子,说明此种方法估计的有效性.     

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     

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