最小均熵差准则与模式聚类

作为最小均方差准则的拓广,本文从数据熵、数据熵差引进最小均熵差准则,并应用于数据与模式聚类;给出基予最小均熵差准则的动态聚类算法与系统聚类算法,最后通过一个应用示例说明这一最小均熵差准则模式聚类的有效性与优越性。     

最小均熵差准则与模式聚类

作为最小均准则的拓广，本文从数据熵，数据熵差引进最小均熵差准则，并应用于数据与模式聚类；给出基予最小均熵差准则的动态聚类算法与系统聚类算法，最后通过一个应用示例说明这一最小均熵差准则模式聚类的有效性与优越性。     

基于中心误差熵准则的非高斯系统滤波器设计

针对现存的最小熵滤波理论由于熵具有平移不变性,基于最小熵准则的滤波方法只能保证估计误差的随机性尽可能小,而不能保证其收敛到零的问题,基于中心误差熵准则研究了一类线性非高斯系统的滤波器设计问题。首先在最小熵准则的框架下采用非参数估计理论和梯度下降法给出了滤波增益矩阵的设计方法,并对滤波误差系统的均方稳定性进行了分析。接着针对最小熵准则的不足,提出了新的中心误差熵准则,它是由信息势和互熵的加权求和构成的,最大化信息势以实现估计误差随机性的全局最小化,最大化互熵可以将误差概率密度函数的峰值固定到零,从而实现滤波误差尽可能小。最后采用数值算例分别针对最小熵滤波和最大中心误差熵滤波进行仿真,结果表明基于中心误差熵准则的滤波算法具有更好的性能。     

信息熵通过系统变化规律的研究

对孤立热力系统中的不可逆过程，热力系统熵自发不可逆地增加；而对自发进行的物理变化过程，物理场熵是减小的。迄今，信息系统中信息熵的变化规律尚不十分明确。对此进行研究，得出结论：带限平稳正态随机信号通过因果最小相位线性系统后，熵可增加或减小，可用线性逆系统使熵可逆变化；平稳非正态独立同分布随机信号通过因果非最小相位线性系统后，熵恒增加，并趋近平稳正态信号，使熵趋于最大。原线性系统不能使熵可逆变化，亦不     

非线性随机系统之熵分析

本文研究一类以It型微积分方程所描述的随机非线性动态系统,借助福克-普朗克方程导出了系统的状态转移概率密度函数之稳态解,并据此分析了系统的熵特性和最小熵参数优化问题。     

给定制冷率时不可逆卡诺制冷机的最小熵产率

导出牛顿定律系统不可逆卡诺制冷机在给定制冷率时的最小熵产率，基于最小熵产率对制冷机的工作性能作了讨论，得到了一些有益的结果。为实际制冷循环的工作参数合理选择提供新的理论依据。     

最小耗能原理再讨论

最小耗能原理不能由普利高津的最小熵产生定理拓展而得到,最小耗能原理只适用于非平衡系统的非平衡定态.     

自然地理区域研究若干问题初探

实际的地理区域的变化是一个非线性的过程,控制区域非线性演化过程的应当是平衡态的最大熵原理和非平衡态的最小熵增率原理. 可持续发展是一个和环境状态密切相关的概念,从系统控制的角度而言,它是一个在系统初始状态已知,系统输入、输出已知的情形下,求出系统终了状态为最优的问题,它的约束条件是不超过环境的最大许可容量. 区域的研究结果具有当地、当时的性质. 应当贯彻天人合一而非以人为中心的发展观.     

热力学非线性区最小熵产生原理和热力学稳定性

经典的非平衡态热力学只能在热力学线性区证明最小熵产生原理,无法在非线性区证明该定理.将热力学熵平衡方程同动力学方程组结合,使最小熵产生原理能够在热力学非线性区得以证明,使之成为非平衡态热力学线性区和非线性区都成立的普遍原理.经典的非平衡态热力学超熵未包括宏观动力过程.必须引入广义动能修正超熵才能作为系统的Lyapounov稳定性函数.但是考虑了动力过程的理想流体负超熵可以直接作为系统的Lyapounov稳定性函数,而且证明导致系统不稳定的原因是流体宏观参数扰动同宏观过程相互作用的结果.对于环境流体这个Lyapounov稳定性判据是目前得到的普遍的稳定性判据.     

流化床非平衡态热力学分析模型

用非平衡态热力学的分析方法分析了流化床系统的熵、熵产生、熵流,讨论了流化床系统的热力学分支和耗散结构分支,论证了流化床系统的能量最小原则,使热力学第二定律同流化床理论研究有机地相结合。建立了鼓泡流化床的数学模型和过渡态判据。热力学第二定律的引入,使热力学和流体动力学与流化床理论研究、耗散结构分支与系统运动形式的多样性、系统总体稳定与局部非稳定在理论描述上相统一。     

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     

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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Brief Introduction to “Journal of Jilin University( Science Edition) ”

<正>"Journal of Jilin University(Science Edition)"is a comprehensive academic journal in the fields of science sponsored by Jilin University and administrated by the Ministry of Education of the Peoples Republic of China.The journal started publication in 1955.The original name at starting publication was"Journal of Natural Science of Northeast People University",which was changed into"Acta Scientiarum Naturalium Universitatis Jilinensis"in 1958 owing to the name change of the university.The present journal name has