基于CoKriging模型的单室火灾温度预测（英文）

高保真数值模拟和单保真机器学习替代模型均需大量时间才能对火场温度做出准确预测,无法满足消防管理的应急需求.为解决上述问题,引入了CoKriging模型,并从建模时间成本、预测时间成本及预测结果准确性这3方面讨论了该模型在单室火灾温度预测中的适用性与特点.该模型利用CFAST和FDS模拟产生的154组混合数据进行训练.交叉验证的结果表明,当高、低保真度数据占比为10∶1时,该模型就能得到有效训练.进一步对不同方法、模型展开对比分析,结果表明,CoKriging模型的预测结果与高保真模拟FDS的计算结果十分接近,且模型一旦构建成功,其做出一次新的预测所需时间远少于FDS.除此之外,在将建模时间成本缩短至1/10的情况下,CoKriging模型仍能达到与单保真替代模型ANN、Kriging一致的预测准确度.实验还发现,高、低保真数据占比不会对CoKriging模型预测结果产生显著影响,即使只有少量FDS数据参与训练,仍能保证CoKriging模型的预测准确性.因此,CoKriging模型可作为一种快速而有效的回归分析方法,应用在单室火灾的温度预测中.     

基于Argo资料的三维盐度场网格化产品重构

针对标准化海洋盐度场产品较为匮乏的事实,利用Argo温盐观测剖面与卫星遥感海表温度资料,采用时空权重插值和多变量DINEOF方法,对太平洋区域2000年1月至2008年12月的三维逐周盐度场进行重构。提出的重构方法有2个明显特色,一是采用时空权重插值与多变量DINEOF相结合的方法,弥补了时空权重插值结果中包含缺失数据的不足;二是引入卫星遥感海表温度,弥补了Argo可靠海表数据的缺乏。重构再分析产品与其他观测和数据产品的对比结果表明,重构产品不但能够抓住盐度分布的主要模态特征,而且可表现盐度不同时间尺度的变化特征,为海洋和气候研究提供了一种有用的标准化数据新产品。     

时空域非参数和多元信息的地质统计学研究

讨论了非参数时空信息统计学(地质统计学)基本理论和方法,即指示函数及二阶矩,Ф(A;Zl)的最优估计以及待估域A平均值的指示Krig估计法和时空域多元信息地质统计学基本理论和方法,即互变异函数及互协方差函数,时空域协同区域化变量的最优估计方法.认为指示Krig法是一种精确和有效的估计地学数据非正态的分布特征方法;在对空间信息研究的过程或事件中,有些变量(经常为多变量)不仅具有空间特征,而且具有时间特征,这时要把所研究的变量看成是时空随机函数.     

流形拓展t-过程回归（英文）

本文提出了一种流形拓展t-过程回归模型,用来分析带有复杂协变量的函数型数据.该流形拓展t-过程回归模型可将协变量数据变换至特征空间,然后用拓展t-过程回归将特征空间数据转换到观测数据空间,从而对观测数据进行建模.我们建立了一个估计程序来估计模型中的参数.对真实数据和模拟数据进行了分析,结果说明所提流形拓展t-过程回归模型是可行的.     

喀斯特地区月均降水协克里金插值方法研究——以贵州省为例

喀斯特山区地形复杂,地势起伏大,降水量时空分布不均匀,尤其是丰水期降水量的分布直接影响当地经济作物的生长,也是地质灾害发生的诱因.以贵州省77个气象站点30 a(1981—2010年)丰水期月均降雨量为基础数据,分析了地形因素(海拔、坡度和坡向)和气象因素(站点压强及相对湿度)与贵州省降水的相关性,并对4种协克里金插值模型方法进行了对比研究.结果表明:采用Pearson相关性分析得出坡向与研究区降水相关性最强,相关系数为0.998.综合对比不同协克里金半变异函数模型(稳定模型、指数模型、球面模型和高斯模型)预测值和实测值的结果表明球面模型的偏差均值最小(MAE=-0.000 4),一致性系数最优(RMSE=0.864).采用球面模型的协克里金插值是进行贵州省降水插值的最好方法,这为更有效地识别出喀斯特地区丰水期降水空间分布提供基础.     

基于变异函数的距离加权反比法

通过插值建立研究变量的数学模型是数据场可视化中至关重要的一步.根据距离加权反比法原理并结合变异函数的优良特性,提出了基于变异函数的距离加权反比法,讨论了其插值特性,给出了近似最大似然法估计协方差参数的原理.通过应用实例比较可知,基于变异函数的距离加权反比法具有效率高、能抵御数据中的噪声、处理数据丛聚效应能力强的特性,其插值效果与克里金法基本相同.     

向量距离中角度信息对时空Kriging的影响

时空Kriging算法的核心,是将变差函数的概念扩展到时空域,变差函数的构建过程基础是计算时间切片和空间切片的向量距离。该文讨论了向量距离对构建时空变差函数的影响,提出了空间距离加角度差异的向量距离模型。以地磁场观测数据作为对象,分别用L1范数、L2范数和新距离模型对数据进行分析,比较3种距离定义下的时空Kriging插值性能。结果表明:加入了角度信息的向量距离,能够更有效地表征数据,提高时空Kriging的插值精度。     

基于CoKriging模型的单室火灾温度预测

高保真数值模拟和单保真机器学习替代模型均需大量时间才能对火场温度做出准确预测,无法满足消防管理的应急需求.为解决上述问题,引入了 CoKriging模型,并从建模时间成本、预测时间成本及预测结果准确性这3方面讨论了该模型在单室火灾温度预测中的适用性与特点.该模型利用CFAST和FDS模拟产生的154组混合数据进行训练....     

基于克里金法的极地海冰密集度空间插值方法

针对海冰密集度再分析产品低分辨率问题，使用普通克里金和改进协同克里金法获取更高分辨率数据。分别选取高斯模型和球形模型对海冰密集度进行空间精细化插值，并对北极可通航水域的插值结果进行精度检验分析。结果表明：变异函数、协变量和目标插值精度对普通克里金和协同克里金插值性能均有影响，并且球形模型在极端数据条件下仍然具有较高的插值精度。克里金法可针对不同实际需求使用不同模型用于极地海冰密集度插值预测，可为极地船舶提供更高分辨率的海冰密集度数据，服务极地船舶安全航行。     

基于Kriging方法的天然地基承载力三维模拟及分析

简要介绍了Kriging方法的基本原理及变异函数的模拟, 并从三维结构模型的体元离散、实验数据搜集与探究、空间变异结构分析以及插值方法应用等方面详细阐述承载力三维实体建模的基本思路。提出以三维地质实体建模技术同Kriging方法相结合的策略分析并模拟天然地基土承载力的空间分布规律, 并以三维可视化技术对其进行刻画和表达。以北京某区域为例, 利用该区887个实验样品数据, 采用Kriging插值与三维实体模型结合的方法, 构建了研究区承载力三维实体模型, 并将模拟结果与传统二维Kriging方法建模结果进行了对比分析。结果表明, Kriging插值与三维实体模型结合的方法不但精度高, 而且直观、准确的三维可视化表现方式为专家的决策提供了便利。     

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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