基因表达式程序设计方法在采煤工作面瓦斯涌出量预测中的应用

基因表达式程序设计是一种基于基因组和表现型组的新型遗传算法，该算法在运行时具有很高的效率，实验表明在求解很多问题的时候比遗传规划优越两个数量级以上．预测采煤工作面瓦斯涌出量是进行通风设计和制定矿井安全技术措施的重要依据，而影响采煤工作面瓦斯涌出量的各因素之间关系不明确．基因表达式程序设计比较适合于求解这一类复杂的非线性问题．本采用基因表达式程序设计，建立了采煤工作面瓦斯涌出量的预测模型．结果表明，预测结果比遗传规划得到的结果具有更高的预测精度和很好的稳定性．章最后指出了该方法具有广泛的应用前景．     

遗传规划在采煤工作面瓦斯涌出量预测中的应用

采煤工作面瓦斯涌出量的预测对于矿井设计和安全生产有着重要意义．由于影响采煤工作面瓦斯涌出量的各因素之间关系不明确,而遗传规划特别适用于各影响因素之间因果关系不明确的复杂非线性问题,因此,它为预测采煤工作面瓦斯涌出量提供了一条新的技术途径．应用遗传规划理论,建立了采煤工作面瓦斯涌出量的预测模型．结果显示,预测精度满足要求．表明该方法是可行的、合理的     

PCA-BP在回采工作面瓦斯涌出量预测中的应用

为对回采工作面瓦斯涌出量进行准确预测,运用主成分回归分析以及BP神经网络原理和方法,结合现场实测数据,采用多元统计分析软件SPSS处理相关数据,研究影响回采工作面瓦斯涌出量各因素间的相关关系并提取主成分,以确定BP神经网络中的输入参数,建立BP神经网络进行预测.利用PCA-BP神经网络方法建立瓦斯涌出量预测模型.研究结果表明:采用PCA-BP神经网络方法的预测值与实际值最大相对误差为2.820%,最小相对误差为2.036%,平均相对误差为2.357%,较其他预测模型有更高精度.对降低事故发生率和矿井延深水平的回采工作面瓦斯涌出量预测具有较好的指导作用.     

采煤工作面瓦斯涌出量预测逐步回归方法

在综合分析矿井瓦斯涌出量影响因素基础上,探讨了采煤工作面瓦斯涌出量与影响因素之间的关系,利用逐步回归分析方法建立了瓦斯涌出量预测数学模型,并将模型应用于平煤天安十矿己组煤层24110采面瓦斯涌出量预测. 结果证明,该数学模型对采煤工作面瓦斯涌出量预测比较准确.     

基于PCA-PSO-ELM的瓦斯涌出量预测

为了更加准确有效地预测瓦斯涌出量,提出采用主成分分析结合粒子群算法、极限学习机的瓦斯涌出量预测方法,其中极限学习机中隐含层节点数量及激活函数的类型由粒子群算法进行组合优化.实验综合考虑影响回采工作面瓦斯涌出量的13个因素对沈阳某煤矿历史数据进行分析,首先采用主成分分析对数据进行降维,消除指标数据之间的相关性,将降维后的数据划分为训练集和测试集2部分,设计了粒子群算法的惯性权重,并由粒子群算法结合十折交叉验证对极限学习机的2个参数进行优化,选择最优参数组合建立预测模型,通过对测试集瓦斯涌出量进行预测,其均方误差为0.108 3,优于采用极限学习机及随机森林的预测结果.     

PCA-BP神经网络在回采工作面瓦斯涌出量预测中的应用

为对回采工作面瓦斯涌出量进行准确的预测,运用主成分回归分析以及BP神经网络原理和方法,结合现场实测数据,采用多元统计分析软件SPSS(Statistical Product and Service Solutions)处理相关数据,研究了影响回采工作面瓦斯涌出量影响因素间的相关关系并提取主成分,以确定BP神经网络中的输入参数,从而建立BP神经网络进行预测.并利用PCA-BP神经网络的方法建立了瓦斯涌出量预测模型.研究结果表明:采用PCA-BP神经网络方法的预测值与实际值最大相对误差为2.820%,最小相对误差为2.036%,平均相对误差为2.357%,较其他预测模型有更高精度.对降低事故发生率和矿井延深水平的回采工作面瓦斯涌出量预测具有较好的指导作用.     

基于PCA-BO-XGBoost的矿井回采工作面瓦斯涌出量预测

针对矿井回采工作面瓦斯涌出量预测精度欠佳的问题,建立基于极端梯度提升(XGBoost)瓦斯涌出量预测模型。首先,为解决瓦斯涌出量影响因素维数高和信息冗余等问题,在预测模型中引入主成分分析法(PCA)对11种影响因素降维。其次,通过贝叶斯优化算法(BOA)对XGBoost中超参数进行优化以提高预测模型的精度。最后,将训练集数据作为预测模型的输入进行训练,利用训练好的模型对测试集数据进行验证,并与传统的BP神经网络和支持向量机进行对比。结果表明：PCA-BO-XGBoost模型的平均绝对误差为0.070 3,均方根误差为0.095 7,能够满足对瓦斯涌出量预测的精度要求。与其他机器学习算法相比,建立的模型预测精度更高、耗时更短、效率均更高,对煤矿井回采工作面瓦斯涌出量的预测精度和效率提升具有借鉴作用。     

综采工作面的瓦斯涌出规律及涌出量的预测

根据综合机械采煤的特点和瓦斯流动理论,将瓦斯涌出源划分为煤壁(围岩)瓦斯涌出、落煤瓦斯涌出、采空区(残煤)瓦斯涌出及上下邻近层(未采分层)瓦斯涌出4个部分。针对现有回采工作面瓦斯涌出量预测计算方法存在的问题,以煤层瓦斯流动理论和实测数据分析为基础,系统的研究了综采工作面涌出源瓦斯的涌出规律,结合综合机械化采煤具有采、装、运连续作业的特点,分别对各瓦斯涌出源的瓦斯涌出量进行预测,进而建立了一种适应性范围广且准确率高的综采工作面瓦斯涌出量预测模型,对制定瓦斯防治方案,进而根治矿井瓦斯具有重要的实际意义。并且运用该模型对潞安集团新建的屯留矿进行了瓦斯涌出量的预测。     

一种基于支持向量机和模型树的回归模型及其在采煤工作面瓦斯涌出量预测中的应用

矿井瓦斯是煤矿生产过程中的主要不安全因素,能否准确预测采煤工作面上的瓦斯涌出量将直接影响矿井开采的经济技术指标.从数据挖掘与机器学习的角度看,瓦斯涌出量的预测问题是回归分析的经典应用.支持向量机和模型树在回归分析方法中显示出了优越的性能,本文应用支持向量机和模型树方法建立采煤工作面瓦斯涌出量的预测模型.实验结果显示,预...     

基于主成分灰关联的瓦斯涌出量预测模型

为分析矿井瓦斯涌出的非线性关系、指标间复杂联系和准确预测瓦斯涌出量,基于主成分分析和灰色关联理论在克服指标的共线性、相关性对瓦斯涌出量影响,兼顾二者关联性之上,确定主要指标,建立瓦斯涌出量预测的距离模型和灰色模型,进而基于支持向量机非线性,构建非线性组合预测模型.利用训练样本学习和最小绝对百分比误差确定预测模型参数,并以沈阳某矿某工作面为例,运用已构建模型预测瓦斯涌出量.研究结果表明:日产量、采出率与其他指标的共线性相对较强,煤层间距、临近层厚度及层间岩性与其他指标的共线性相对最弱;该模型绝对百分比误差最大为5.83%,预测精度相对高于各个单项预测模型,大幅降低预测风险.     

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