股票价格的马氏链预测法

马氏链预测法是通过对事物不同状态的初始概率及状态之间的转移概率的研究,预测事物的未来状态。本文建立了股票价格预测的马尔可夫链数学模型,并举例说明了该模型在股票交易市场预测中的应用。     

股票的价格模型及其投资的最优停时

建立了一个弱型市场中股票价格的离散化模型，在贴现率为时间的函数和随机过程的两种情况下，求出了相应股票投资中的最佳买入卖出停时及最优报酬。     

基于时变状态转移隐半马尔科夫模型的寿命预测

隐半马尔科夫模型在进行系统状态估计及寿命预测时,其状态转移概率矩阵是固定值,得到的剩余寿命预测值呈阶梯状变化,与系统的实际剩余寿命值之间存在着较大的误差.针对上述问题,提出了具有时变状态转移概率矩阵的隐半马尔科夫模型,根据系统的3种典型退化状态分析,给出3种不同的状态转移系数.与初始状态转移矩阵相结合,得到随时间变化的状态转移矩阵.提高系统在当前健康状态下的剩余持续时间估计精度,最终得到更为准确的总体剩余寿命预测值.结果表明,基于时变状态转移概率矩阵的隐半马尔科夫模型相比传统的隐半马尔科夫模型,可显著提高剩余寿命预测的准确性.     

连续时间首达目标模型(Ⅱ)──L最优问题

研究了连续时间首达时间及首达目标总报酬（非折扣）的Ｌ最优模型。给出新的ｋ阶矩简洁表示式；证明Ｌ最优模型可化为离散时间拟折扣期望报酬优化模型；给出Ｌ最优与Ｍ最优之间的关系与若干性质。     

生产企业的材料替代策略

研究了生产企业年总需求量一定,库存占用资金在一定范围内变化,材料之间替代率一定的情况下,生产企业减少库存成本的一种策略材料替代策略·为了研究该策略的可行性,分别给出了不采用替代策略和采用替代策略两种情况下企业的订货量确定模型·模型中考虑了库存成本的资金约束范围·在借入资金和所有者投入资金的情况下,都考虑了资金的持有成本,分别以库存平均占用资金所支付的利息率和资金的平均收益率来衡量·在采用材料替代策略时还考虑了材料之间的其他替代比率关系·应用进化规划算法对模型做了仿真计算·分析指出,一定条件下,材料替代策略可以降低库存成本·     

具有阶段结构的单种群模型的脉冲控制

利用脉冲微分方程的比较原理,通过状态反馈及输出反馈对具有阶段结构的单种群模型变换后的系统进行了脉冲控制·对成、幼年种群同时捕获,首先通过状态反馈,得到了使系统在正平衡点渐近稳定的充分条件·然后通过输出反馈得到了相应的结论·最后,对所实施的使系统渐近稳定的脉冲控制,给出了脉冲控制时间间隔的上界估计值·文章的结论蕴含着系统的持续生存     

标的资产服从几何Levy过程的股票价格模型的期权定价

利用公平保费原则和价格过程的实际概率测度推广了Mogens Bladt和Hina HviidRydberg关于欧式期权定价的结果．在假定股票价格过程遵循几何Levy过程,并且股票预期收盖率、波动率和无风险利率均为时间函数的情况下,获得了欧式期权精确定价公式和买权与卖权之间的平价关系．     

基于Copula的海洋生态系统的稳态转换

基于藻类与食植鱼类的生态动力学模型,采用非线性动力学方法,确定了典型控制参数的分岔区域．运用Copula方法,通过历史数据得到控制参数的概率分布．以分岔区域作为不同状态,建立了系统状态转移的马尔科夫链模型运用蒙特卡罗方法计算转移概率矩阵,得到多稳态转换的平稳概率,并得到了使期望状态平稳概率最大化的控制参数值     

跳-扩散模型下复合期权的保险精算定价

假定股票价格过程遵循跳-扩散过程,并且股票预期收益率,波动率和无风险利率均为时间的函数的情况下,利用价格过程的实际概率测度和公平保费原理,获得复合期权价格表达式.     

随机观测下两面跳的对偶风险模型

主要研究随机观测下对偶风险模型的期望折现罚金函数.首先,利用过程的马尔可夫性得到了期望折现罚金函数所满足的积分微分方程.其次,当罚金函数取不同的值时,得到了破产时的Laplace变换、破产时赤字的期望折现函数以及破产概率所满足的积分微分方程.最后,给出了两面跳均服从指数分布情况下破产概率的显性表达式以及具体的数值例子.     

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.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

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