一种基于BP神经网络和小波变换的网络流量预测模型

结合小波变换和BP神经网络,建立一种网络流量预测模型.首先对流量时间序列进行小波分解,得到多个尺度的小波系数序列,以系数序列和原来的流量时间序列分别作为模型的输入和输出,构造人工神经网络并且加以训练.用实际网络流量对该模型进行验证,结果表明,该模型具有较高的预测效果.     

基于小波神经网络的实际业务流预测方法

针对无线传感器网络传输过程中容易受到噪音干扰的问题,提出了一种新的业务流预测算法AWNNP(Ant colony-based Wavelet Neural Network Prediction).该算法首先利用小波变换对业务流进行分解,并将其小波系数和尺度系数作为样本数据.其次,结合蚁群算法和神经网络来训练样本数据,采用小波模型重构进行重构,以此获得业务流的预测数据.同时,通过仿真实验对比,并分析了小波神经网络预测算法和BP神经网络预测算法,实验结果表明,AWNNP算法性能较优,其误差为16.21%.     

基于神经网络的VBR视频流量建模及预测

为解决视频流量预测问题,结合神经网络和小波技术建模IP(Internet Protocol)网络视频流,提出了利用神经网络预测尺度因子的预测算法.对可变比特率的压缩视频流完成小波分解,得出尺度因子.通过对尺度因子的预测和小波重建,完成视频流量预测.尺度因子的归一化特性简化了神经网络处理过程.对真实VBR(Variable Bit Rate)视频流的流量预测实验表明,模型对IP网络普遍应用的高压缩比视频流具有良好的预测能力.     

小波变换在径流序列中应用

小波变换被应用到径流分析中,以获得径流序列的组成,并预测未来的径流.用几个小波函数对观测的径流序列进行了分解和重构,并展示了其发展趋势;用BP神经网络、小波变换结合BP神经网络,对引用的径流序列进行了预测.最后,对影响计算结果的因素进行了分析,并对小波函数在径流分析中的应用提出了建议.     

小波神经网络的毫米波雷达目标一维距离像识别

将小波变换和反向传播神经网络理论结合，设计一种小波神经网络结构。由于小波变换在时间和频率空间所具有良好的定位特性，使小波神经网络可对输入输出数据进行多分辨的学习训练。介绍神经网络的数学框架和该网络的学习算法。根据毫米法频率步进雷达目标一维距离像所给出的信息，将所提出的小波神经网络用于3种实际雷达目标的识别。实验结果表明，小波神经网络收敛速度快、识别率高。     

用二元树复小波变换法实现离焦图像的半盲复原

提出了一种基于二元树复小波变换和神经网络的半盲离焦图像复原算法,首先利用二元树复小波变换和特征值分解提取图像的特征矢量,将该矢量用来训练小波神经网络,利用训练好的网络估计离焦模糊参数.由此获得点扩展函数,用Wiener滤波完成图像的复原.实验结果表明,该方法能有效地估计离焦模糊参数和复原模糊图像.     

一种基于小波变换和FARIMA模型的网络流量预测算法

提出了一种新的基于小波变换和FARIMA模型的流量预测方法,首先对原始流量进行小波分解,再进行mallat算法单支重构,接着用FARIMA模型分别对重构后的单支进行预测,最后整合流量.我们用真实网络流量进行了仿真实验,验证了提出算法的预测准确性,较之首先用FARIMA模型对小波系数进行预测再进行小波重构的方法减小了预测...     

一种改进的小波神经网络的网络流量预测算法

为了有效地对网络进行维护,提高网络性能,预知网络流量可以提前对网络出现的问题采取应对策略,从而对用户提供更好的服务。在神经网络预测模型中把隐含层的传递函数用小波函数替换,并采用共轭梯度下降算法,建立了一个小波神经网络的网络流量预测模型。通过实际流量数据对模型进行仿真,结果显示该模型与神经网络预测模型相比,该网络具有良好的预测效果,网络训练时间短,有效地提高了训练速度。     

模糊耦合神经网络的系统供热预测研究

热流量的准确预测,对于日益庞大的城镇供热系统能效提升起着至关重要的作用。首先对影响热流量的各因素应用数理统计的方法进行分析,然后采用模糊耦合神经网络算法对供热系统建立热流量预测模型,并通过某热源的历史运行数据进行分析,与小波神经网络算法比较,证实了该耦合算法的高准确性。这种将模糊理论与神经网络相结合的预测方法兼顾了二者的优点,使其既具有模糊逻辑的不确定信息处理能力,又可以有神经网络的自学习能力。该研究符合城镇供热系统非线性的特性,可以应用于智能热网的热流量预测。     

基于小波神经网络的化工安全评估

鉴于传统神经网络方法解决非线性问题收敛速度慢,易陷入局部最优解的缺陷,本文通过对小波神经网络的结构及学习算法的简要介绍,结合神经网络的自学习能力,提出一种充分利用小波变换时频局部化性质的小波神经网络安全评价方法,通过用小波神经网络评价方法与BP神经网络评价方法对某大型炼油化工厂相应原始数据进行分析、对比,表明该小波神经网络评价方法较BP神经网络评价方法收敛迅速,绝对误差小,预测精度高。     

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     

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