基于径向基神经网络的非线性自适应除噪

提出一种适用于非线性自适应除噪（ＡＮＣ）的神经网络方法．当参考通道中噪声是主通道噪声的非线性变换时,采用线性ＡＮＣ往往效果不好,此时应采用非线性ＡＮＣ．由于径向基函数网络有良好的非线性函数逼近性能,因而可采用基于径向基函数网络的非线性ＡＮＣ．模拟结果表明,该方法具有很强的噪声抑制能力．     

基于低松弛迭代格式的快速自适应滤波算法

利用Ｂ样条函数基底的光滑性及其局部支撑性质,以最小二乘（ＬＳ）为准则,构造了基于低松弛迭代格式的快速自适应滤波算法．对于一个Ｎ×Ｎ输入图像,由于Ｂ样条函数的局部支撑性质以及低松弛迭代算法的引入,使得在统计意义下最佳的最小二乘滤波算法的计算复杂度降为Ｏ（Ｎ２）,就ＬＳ算法的复杂性而言,优于不动点（ＦＰ）迭代算法的Ｏ（Ｎ３）及基于ＦＦＴ的预处理共轭梯度（ＰＣＧ）算法的Ｏ（Ｎ２·ｌｎＮ）．实验结果表明,该滤波器对Ｇａｕｓ白噪声及均匀分布的噪声图像具有良好的降噪特性．     

基于改进kmeans聚类方法的RBF神经网络设计

提出了一种利用改进的kmeans聚类算法确定径向基函数的数目、基函数中心及宽度,输出层权值由线性方程组确定的RBF网络设计方法．通过对函数逼近的仿真实验,表明该RBF网络比Kmeans聚类算法设计的RBF网络更加稳定高效．     

基于神经网络的非线性自适应除噪研究

提出一种适用于非线性自适应除噪（ANC）的神经网络方法。当参考通道中的噪声是主通道噪声的非线性变换时，采用线性ANC往往效果不好，此时应采用非线性ANC。由于径向基函数网络具有良好的非线性函数逼近性能，因而可采用基于径向基函数网络的非线性自适应除噪。模拟结果表明，这种方法具有明显的抑制噪声能力。     

紧支撑径向基函数网络在函数逼近中的应用研究

径向基函数网络能够以任意精度逼近任意连续函数。目前径向基函数神经网络中普遍使用高斯基函数作为激励函数,用它来训练网络时,首先需要确定径向基函数的扩展常数SPREAD.SPREAD设定过小,函数逼近时会出现过适性,SPREAD过大,函数逼近时会出现不适性。所以创建径向基函数网络时,需根据不同的训练集和精度要求,选择多个不同的SPREAD值来反复比较网络输出值和目标值,以确定相对较好的逼近情况,这给实际使用带来一定的困难和不便,且无法保证该选择是最佳值.本文研究使用紧支撑径向基函数作为激励函数来设计神经网络,并分析其在函数逼近中的实际应用。     

用于干涉型光纤陀螺温度漂移辨识的RBF神经网络改进算法

针对干涉型光纤陀螺(IFOG)温度漂移的辨识,推导了径向基神经网络(RBFNN)中隐含层神经元、网络的抗噪声性能和拟合精度三者之间的关系,并在此基础上提出了一种新的径向基函数神经网络辨识学习规则.该方法具有很强的抗噪声性能,网络输出不会被陀螺噪声所污染,同时能动态地确定神经元数,辨识精度高,有效地避免了传统RBF网络学习算法中事先固定网络结构可能存在的盲目性.实验结果表明,该方法能够快速、准确地辨识IFOG的温度漂移.     

基于Zernike矩特征的FCM-RBF神经网络图像分类器

针对交通监控图像识别精度较差的问题,设计一种基于径向基(radial-basis)函数神经网络的图像分类器.该分类器利用Zernike矩噪声敏感度较小、形状特征稳定性好的特点,构建四阶矩的特征向量,用于特征提取;利用自适应模糊聚类方法,解决径向基函数神经网络隐层节点数不确定的问题.仿真分析表明,该分类器与基于改进的快速模糊C均值聚类算法的Back Propagation网络分类器和径向基函数神经网络分类器相比具有更高的识别率,与改进的粒子群优化模糊C均值聚类算法的径向基函数神经网络分类器相比具有相近的识别率,但其计算复杂度较低.仿真实验结果表明,该方法具有较好的分类能力及较高的计算效率.     

基于余弦函数的神经网络硬件实现

研究了正交余弦基函数神经网络模型和学习算法, 给出了仿真实例, 并提出了余弦函数基神经网络模型电路实现方案.仿真结果表明,该网络学习收敛速度快,可任意逼近非线性映射等优异性能. 此外,网络结构简单,便于电路实现, 一个余弦波振荡源经倍频即可实现隐层神经元电路.     

基于RBF网络的ECT图像重建算法

介绍了一种基于RBF网络的电容层析成像图像重建算法,包括径向基函数的选取、RBF网络权值的训练方法.仿真实验显示该算法可用于两相流流型辨识.     

Poisson型密数在多项式加权空间的逼近特征

利用Ｐｏｌｙａ基函数构造一类Ｐｏｉｓｓｏｎ型密度函数，并研究Ｐｏｉｓｓｏｎ型密度函数在多项式加权空间的逼近特征．     

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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