基于核和精确度的三参数区间灰数预测模型

针对传统灰色预测模型只能解决实数序列和区间灰数序列预测的不足,提出了三参数区间灰数的预测模型.通过定义三参数区间灰数的核和精确度,进而得到三参数区间灰数的核序列、"重心"点序列和精确度序列,从而将三参数区间灰数序列预测转变成实数序列预测,分别对三组序列建立预测模型,在不破坏灰数整体性的前提下,推导还原得到三参数区间灰数的预测模型,并对其进行精度检验,最后用一个实例来验证所建模型的有效性和实用性.     

基于XGBoost的短时交通流预测模型

为提高路段短时交通流的预测精度,选取路段平均旅行时间作为预测指标,建立了一种基于极端样度上升(extrem gradient boosting,XGBoost)的短时交通流预测模型。首先通过对交通流数据的分析,在考虑交通流时空特性的基础上,分别构建目标路段时间序列训练集、测试集以及时空序列训练集、测试集,然后基于XGBoost模型以及构建的训练样本集建立时间序列预测模型以及时空序列预测模型,并利用训练好的模型进行预测,最后将模型预测结果与线性回归模型、神经网络模型预测结果进行比较。实验结果表明:基于XGBoost的短时交通流预测模型能够对路段未来时段平均旅行时间进行比较准确的预测,其中时间序列预测模型均方根误差为5. 32,时空序列预测模型均方根误差为4. 82,均低于线性回归模型和神经网络模型,且相比于仅考虑时间因素的短时交通流预测模型,同时考虑时空因素的预测模型得到的误差更低,预测效果更好。     

基于区间数距离和ICOWA算子的变权区间组合预测模型

针对预测值为区间数形式,将区间数距离和诱导连续有序加权平均算子ICOWA结合,以ICOWA算子下实际预测序列与组合预测序列的距离最小为准则,构建了变权组合预测模型,并证明了模型的非劣性.最后,通过实例说明了模型能够有效提高预测精度.     

基于人工神经网络与回归分析的水质预测

针对人工神经网络(Artificial Neural Networks,缩写ANN)在预测中出现的异常值现象,采用了回归分析模型得到的预测区间来控制异常值现象的方法.并且应用在黄河三门峡河段的水质预测中,氨氮通量预测的ANN模型控制前平均精度仅有50.05%,控制后该月的相对精度为90.08%,平均精度达到80.79%,整体预测精度明显提高.化学需氧量(COD)浓度的预测也有类似情况.实践表明该方法对于消除ANN模型预测中出现的异常值现象是较为有效的.     

一类区间灰数预测模型直接建模法

为利用直接建模思想,推导得出了一类新信息GM(1,1)直接模型形式.传统模型只能针对实数序列进行建立模型.以区间灰数的"核序列"为基础,并结合"信息域不减"原则,构建相应的GM(1,1)区间灰数预测模型;通过以"核序列"为中心,推导出所建模型区间灰数上下界的时间响应式.实例结果表明:该改进模型可以有效提高预测精度.     

基于区间数距离的区间组合预测模型

针对预测值为区间数形式,引入区间数距离,提出一种确定区间组合预测权系数的方法.给出两个区间序列的距离公式,以实际观测序列与组合预测序列的距离最小为准则,建立规划模型,求解得到权系数.最后,通过实例,证明模型能够有效提高预测的精度.     

基于核和认知程度的区间灰数Verhulst预测模型

针对传统的Verhulst模型只能用于对实数序列进行建模预测的问题,将其建模对象扩大到区间灰数序列,构建基于核和认知程度的区间灰数Verhulst预测模型.首先,将区间灰数序列转化为核序列和认知程度序列,实现区间灰数的白化;然后,分别构建核序列和认知程度序列Verhulst模型,并反推区间灰数上下界的表达式;最后,将模型应用于某高层住宅沉降量预测并与其他模型结果对比,实例表明,所建模型的精度较高,具有实用性.     

一类灰色Verhulst模型的优化

针对传统模型仅限对实数序列进行建模的缺陷,利用直接建模思想,得到一类Verhulst模型直接形式,并对区间灰数序列的下界序列进行预测;同时结合"信息域不减"原则,推导出上界序列的预测表达式,从而实现对区间灰数的模拟、预测.通过实例表明,该区间灰数预测模型具有很好的有效性和实用性,拓宽灰色预测模型的范围.     

基于IOWHA算子的区间预测模型及应用

针对实际值序列和预测值序列均为区间数的组合预测问题,把区间数的左右端点作为两个独立的时序数列,通过引入诱导有序加权调和平均(IOWHA)算子,分别建立以区间数左右端点的倒数离差相关系数最大化为准则的IOWHA算子的变权系数最优组合预测模型,再通过引入偏好系数把多目标最优化模型转化为单目标最优化模型,并尝试给出各模型最优解的性质.最后利用数据进行分析,并和其他单项预测方法或组合预测方法相比较,从而证明该方法确实能够提高区间预测的精度.     

一类日极端温度的变权系数区间型组合预测模型

为提高日极端温度的预测精确度,提出了一类基于区间数相关度与GIOWHA算子新型区间数组合预测模型。将区间数转化为等价信息的中心和半径,以相关度作为最优准则,构建基于区间数相关度的定权系数区间型组合预测模型。并引入GIOWHA算子,将区间数预测精度作为诱导因子,构建基于区间数相关度与GIOWHA算子的变权系数区间型组合预测模型。并将变权系数区间型组合预测模型应用于日极端温度区间数序列的预测中,实例证明该模型的有效性,并对模型的参数进行了灵敏度分析。     

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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