前馈网络灵敏度：分析及降低算法

在前馈网络中，不同的权值组合可逼近同一映射。网络的灵敏度取决于权值的变化。文中提出了计算网络灵敏度的方法和一种降低网络灵敏度的学习算法。网络的灵敏度分析包括单输出、多输出及输入变化、权值变化等情况。学习算法是在网络训练过程中加入随机噪声。次种学习算法与传统学习算法相比，可降低网络的灵敏度，但学习收敛速度基本相同。     

一种BP神经网络的改进方法及其应用

针对BP神经网络中学习因子取值小、收敛性好但训练时间长，学习因子取值大、权值变化剧烈但可能导致振荡的情况，提出了一种修正学习因子的方法，即给学习因子前加一比例因子，在网络权值调整过程中自动调整学习因子的大小，使网络训练时间短，而且收敛效果较好。仿真结果表明，在导弹指令跟踪中，改进算法比原来算法优越得多。     

前馈神经网络的逐层优化学习算法

提出了求解前馈神经网络的逐层优化学习算法，首先对输出层权值进行优化，然后再对隐层权值进行优化，如此交替迭代直至求出最优解。在分层优化过程中，对节点激池数进行了线性，同时为防止由于线性化造成较大的误差，在目标函数中加入惩罚项。     

基于遗传算法的人工神经网络优化设计

提出遗传算法新的编码方案，用于全局优化神经网络拓扑结构和权值参数，解决了神经网络拓扑结构的难确定性和权值训练的长时性问题，并且在遗传操作中采用自适应代沟的替代策略，改善其求解效率，获得了良好的优化结果。通过仿真实验显示了该算法的快速性和有效性。     

神经网络迭代学习控制快速算法的研究

研究了非线性系统的神经网络迭代学习控制问题，为了提高神经网络学习控制的收敛速度，改进了权值的迭代学习算法，提出了一种新的训练权值方法，它以递推的方法来计算网络权值，不仅能减少计算量且收敛速度快，最后，用仿真结果对该算法作了进一步的验证。     

基于进化规划的神经网络设计方法

利用进化规划同时进化神经网络的结构和权值。为了避免在网络中形成信号的冲突和竞争，用连续规则决定神经元之间的连接方式。在进化规划中，变异分为结构变异和权值变异两种。提出在静态网络中引入延时权概念来构成时序网络，从而将静态网络的设计方法推广到时序网络的设计，最后给出了仿真结果。     

利用修正的BP神经网络进行框架结构损伤诊断

提出了一种基于修正的BP神经网络方法的结构损伤诊断方法，该方法通过基于误差曲面调整权值以及引入动量因子算法来避免出现局部极小，并通过自适应调整学习速率来提高学习效率，从而解决了传统BP神经网络在实际应用中存在的收敛速度慢和存在局部极小的问题。算例表明，该方法能够不仅较为准确的检测出结构的不同程度损伤，而且提高了计算效率，同时具有较强的鲁棒性。     

用FPGA实现的复合神经网络自学习算法电路

介绍复合神经网络模型及特性，讨论了基于假逆矩阵的自学习算法，研究用现场可编程门电路（ＦＰＧＡ）实现复合神经网络的自学习过程，电路设计成半并行全数字式．实验结果表明其权值学习结果与计算机软件模拟结果一致，而其运算速度是软件模拟无法比拟的     

基于BP网络的非线性广义预测学习控制器

本文提出了一种基于ＢＰ神经网络的非线性义预测学习控制器，它由一个ＢＰ网络构成。在整个学习与控制过程中，首先根据被控对象的输出与ＢＰ的学习输出之间的误差来修改网络的权值，以逐步建立被控对象的合理的多步预报模型；然后，根据网络的多步预报输出序列与设定值序列的偏差修改控制律。     

基于关键原子动作的视频事件学习与识别方法

提出了一种基于关键原子动作的视频事件学习与识别方法. 通过与或图来表示事件、子事件、原子动作之间的层次结构,以及子事件和原子动作间的时序关系,通过最小描述长度准则从训练数据中学习事件的与或图结构. 在此基础上,提出了一种事件中关键原子动作的学习方法,根据原子动作的重要性赋予相应的权值,该权值可以用于事件的实时解析,提高事件的识别率. 基于原子动作的权值及漏检数目定义了事件的可识别度,用于减少待识别的事件数目,进而提高事件识别的算法效率. 多种场景实验结果表明所提出的方法可以有效地进行事件识别.      

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