基于小波与DBN的负荷预测模型

针对原始数据存在干扰以及BP神经网络和深度置信网络(DBN)局限性的问题,提出了一种小波与DBN相结合的负荷预测模型.该方法主要是先将原始负荷数据进行小波降噪,将降噪后的数据用来训练DBN模型,最后用该模型进行负荷预测.分别对比BP、DBN以及小波与DBN组合模型对负荷的预测结果与真实值的差异,仿真结果表明小波与DBN组合预测模型预测曲线趋势和真实值的一致性最好,从数据中得出BP、DBN以及组合模型预测结果的均方根误差分别为23.862、13.656和10.477,说明小波与DBN组合模型对负荷预测的准确性最高.     

城市用水量非线性组合预测方法研究

利用小波网络构造模型的优化组合函数,建立了城市用水量非线性组合预测模型.将非线性组合函数的拟合转化为小波网络参数的估计,采用遗忘因子法训练网络的权值,利用递推预报误差算法训练尺度因子和平移因子.实例表明,该方法具有很强的泛化能力与自适应数据和函数变化的能力,能够有效提高预测精度,克服了线性组合预测方法适应性不强的问题.     

混沌时间序列的自适应正交小波神经网络预测

针对非线性混沌时间序列预测问题,提出一种基于正交小波神经网络的自适应预测算法.根据来自非线性序列模型的期望输入输出数据,利用小波框架理论建立初始的小波神经网络.采用正交化逐步选择方法对于初始小波神经网络进行结构优化,从而建立最精简的网络模型.同时引入在线学习算法在线修改网络权值和小波神经元的参数,从而提高模型的自适应能力和泛化能力.通过对时滞Mackey-Glass超时间序列和时变Lorenz混沌序列的预测,证明了算法的有效性.     

最小二乘支持向量机的短期负荷多尺度预测模型

提出了一种改进的电力负荷短期预测小波网络模型，该模型采用最小二乘支持向量机(LS-SVM)实现了小波分解系数的多尺度组合预测．首先使用多孔算法对短期负荷序列进行小波分解，得到指定尺度下的近似系数和相关尺度下的小波系数，然后利用LS-SVM对预测点的系数进行多尺度组合预测，通过小波重构可以求得相应的预测值．结合某地区短期负荷需求数据进行了仿真试验，研究了预测点与历史记录数据的相关关系．预测结果表明，使用本模型进行短期负荷预测同比传统小波神经网络方法可以获得更好的预测精度，同时LS-SVM的引入大大提高了模型的可计算性．     

基于小波神经网络的风速预测及置信区间估计

小波神经网络是在小波变换理论和人工神经网络的基础上建立的一种新型网络模型,综合了两者的优点,克服了BP神经网络易陷入局部极小点和训练速度慢的缺点.本文建立了小波神经网络模型,采用最陡梯度下降法训练网络,将该网络用于对风电场小时风速的预测,并对预测置信区间进行计算.预测结果表明小波神经网络在训练速度和预测精度方面均优于BP神经网络.     

小波优化多任务学习的综合能源负荷预测

为实现多元负荷快速、准确短期预测,提出一种小波优化多任务学习的综合能源负荷预测方法.采用多任务学习神经网络方法,设置参数的软共享机制,不仅可以提高模型泛化能力,而且可以提高综合能源系统负荷预测方法鲁棒性.通过设置特殊的隐藏层激活函数,使得预测负荷时,保证网络解唯一性,防止局部极小值点,提高收敛速度,保证其综合能源系统电...     

武器装备研制阶段费用预测方法及仿真

提出一种基于小波神经网络的武器装备研制阶段的费用预测方法.建立小波神经网络预测模型,并推导该模型的预测算法.应用一组美军反舰导弹数据进行仿真预测.结果表明,小波神经网络方法比传统BP网络方法平均预测误差减小了1%,收敛速度加快了3倍.     

基于K均值小波神经网络的二阶段空调负荷预测

结合聚类分析和小波神经网络模型,提出一种二阶段空调负荷建模方法,以提高空调负荷预测精度.首先利用K均值聚类算法将原始负荷样本数据依据其统计分布特性划分为若干簇类,以降低数据相关性对建模精度的影响;然后基于对每个划分簇类所属的样本数据建立相应小波神经网络空调负荷预测模型.最后基于De ST平台模拟数据,将构造的小波神经网络预测模型运用于福建某办公大楼的逐时空调负荷预测.通过对比均方根误差(RMSE)和平均绝对误差(MAPE),结果表明该模型的预测精度明显优于传统单一的小波神经网络和BP神经网络模型.     

短期电力负荷预测的小波支持向量机方法研究

在充分研究和比较多种负荷预测方法的基础上，提出一种称为小波支持向量机(Wavelet Support Vector Machines，WSVM)的负荷预测新算法．该方法是在研究支持向量机(SVM)核方法与小波框架理论的基础上，引入非线性小波基函数来构造SVM的核函数，从而得到新的SVM模型，并给出了此模型的结构设计与实现算法．通过实例验证，该方法能有效提高预测精度．     

基于DE-ELM算法的配电网电力系统负荷预测研究

针对目前方法对配电网电力系统进行负荷预测时,由于未能在电力负荷预测前对电力数据进行缺失值插补处理,导致该方法存在预测精度差、时间长以及性能差的问题,提出一种基于DE-ELM(Differential Evolution-Extreme Learning Machine)算法的配电网电力系统负荷预测研究方法。首先依据小波变换对电力数据进行去噪处理,根据去噪结果完成电力数据缺失值的插补,获取完整的电力数据集;再将数据集分成训练集与测试集两部分,将全局寻优引入极限学习机,采用DE-ELM算法对训练集进行计算,依据结果建立网络模型;最后将测试集放入构建的模型中进行训练,基于输出结果实现配电网电力系统的负荷预测。实验结果表明,运用该方法进行配电网电力系统负荷预测时,预测精度高、时长短、性能好。     

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     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

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