灰色关联分析和多元二次非线性回归分析模型研究及应用

基于大庆油田采油二厂压裂措施资料,运用灰色关联分析方法选取对裂缝导流能力影响较大的因素,然后运用多元二次回归分析做进一步的定量研究,并与DPS系统的分析结果进行对比。结果表明,灰色关联分析可以较好的得到与裂缝导流能力关系密切的因素,回归分析可以得出因素间的具体定量关系,且回归分析计算的精度较高,多元二次回归分析和DPS平均拟合误差分别为0.940%、0.916%,预测平均误差分别为1.850%、1.831%,研究为油田开发动态数据规律研究提供了有效的方法。     

回归方程在标准加入法测高岭土中铜的应用

用原子吸收光谱法测定高岭土中铜,分别用标准曲线法及标准加入法定量分析铜元素含量,比较了作图法和回归方程法处理标准加入法数据。结果表明,随铜元素变量,标准曲线法及标准加入法均有较好的线性关系,但测定的结果有差异。标准加入法因可消除基体干扰,测得铜结果准确度高。标准加入法适合基体复杂的试样的分析。作图法及回归方程均适用于标准加入法测铜的数据处理,作图法误差大,而回归方程法是快捷,误差小的简便方法。     

傅里叶变换近红外光谱法应用于聚乙烯树脂的正己烷提取物分析

采用偏最小二乘法(PLS),建立了傅里叶变换近红外漫反射光谱法检测聚乙烯树脂正己烷提取物的数学模型。分析过程选择了最佳光谱预处理方法、谱区范围及主因子数,并使用内部交叉验证对模型进行验证。实验结果表明,当选择最小-最大归一化的光谱预处理方法,谱区范围7 501.8～6 097.9 cm-1和5 025.6～4 597.5 cm-1,主因子数8时定量模型的准确度最好,决定系数(R2)和均方差(RMSECV)分别为0.988和0.416,近红外测定值与标准方法测定值基本一致。对297种牌号共1 251个进口聚乙烯树脂正己烷提取物项目的普查结果表明,聚乙烯树脂正己烷提取物项目的总体安全性较低,属于进口聚乙烯需重点关注的安全卫生项目。     

吴旗油田吴410井区长6油层组流动单元研究

本文以吴旗油田吴93井区油藏为例,在吴93井区沉积微相、储层综合分析评价的基础上,选取有效厚度、渗透率、孔隙度、含油饱和度、渗流系数、储能系数、流动层指数和油藏品质指数等八个参数进行流动单元的划分。将长6油藏划分为A,B,C和D四类流动单元。划分结果表明,吴93井区长611和612是该区长6油藏的主力油层,各类流动单元与储层岩性、物性和沉积微相具有很好的对应关系。本次流动单元划分的参数取值,综合评价函数与评价指标,可以客观地反映低渗、低孔、储层物性差、非均质性强等地质特征。     

Mapping of background air pollution at a fine spatial scale across the European Union

Background

There is a need to understand much more about the geographic variation of air pollutants. This requires the ability to extrapolate from monitoring stations to unsampled locations. The aim was to assess methods to develop accurate and high resolution maps of background air pollution across the EU.

Methods

We compared the validity of ordinary kriging, universal kriging and regression mapping in developing EU-wide maps of air pollution on a 1 × 1 km resolution. Predictions were made for the year 2001 for nitrogen dioxide (NO₂), fine particles < 10 µm (PM₁₀), ozone (O₃), sulphur dioxide (SO₂) and carbon monoxide (CO) using routine monitoring data in Airbase. Predictor variables from EU-wide databases were land use, road traffic, population density, meteorology, altitude, topography and distance to sea. Models were developed for the global, rural and urban scale separately. The best method to model concentrations was selected on the basis of predefined performance measures (R², Root Mean Square Error (RMSE)).

Results

For NO₂, PM₁₀ and O₃ universal kriging performed better than regression mapping and ordinary kriging. Validation of the final universal kriging estimates with results from all validation sites gave R²-values and RMSE-values of 0.61 and 6.73 µg/m³ for NO₂; 0.45 and 5.19 µg/m³ for PM₁₀; and 0.70 and 7.69 µg/m³ for O₃. For SO₂ and CO none of the three methods was able to provide a satisfactory prediction.

Conclusion

Reasonable prediction models were developed for NO₂, PM₁₀ and O₃ on an EU-wide scale. Our study illustrates that it is possible to develop detailed maps of background air pollution using EU-wide databases.     

高速铣削Mg-Al-Zn-Mn系镁合金时切削力影响因素析因偏回归研究

在切削速度471.24～942.48 m/min,每齿进给量0.05～0.2 mm,背吃刀量2～4 mm范围内,研究了高速端面铣削Mg-Al-Zn-Mn系镁合金过程中主切削力的变化规律,并从切削变形机理上进行了讨论与分析.通过L8(23)析因分析与偏回归分析,考察切削用量对铣削力的影响规律,使用残差分析与最小二乘法等统计方法,建立了主切削力与切削用量的经验公式.研究结果表明:高速铣削时,背吃刀量和每齿进给量是对主切削力有显著影响的效应因素;在试验速度范围内,随切削速度的增大,主切削力将成下降趋势;在选定的切削用量范围内,实际测量切削力与由经验公式计算结果较为吻合.     

A regression model for prediction of pipe conveyor belt contact forces on idler rolls

The paper presents design and verification of regression models for prediction of pipe conveyor belt contact forces on idler rolls. Their advantage is in the fact that they have been created according to the real experimental measurement. The obtained models correspond with real operational conditions. The concept of the experimental rig at the Technical University of Košice is designed so that it represents 8 m long section of pipe conveyor. The conveyor belt is an object with action of tension force and at the same time it takes the initiative in the contact force formation. Several criteria have been used to verify the presented regression models. The tensioning force 9000, 12,000 and 15,000 N have MPE of prediction error less than 5%. About 120,000 measured values have been processed during the evaluations which correspond to approximately 15,000 results from experimental measurements.     

基于支持向量回归的腔体滤波器机电耦合建模与优化

为了提高装配后的滤波器电性能和成品率,该文提出了一种基于支持向量回归的腔体滤波器机电耦合建模和优化方法。该方法根据工程中积累的经验数据,首先应用改进的多核线性规划支持向量回归算法建立了制造精度对滤波器电性能影响的机电耦合模型,然后应用此模型优化了滤波器的制造精度,从而获得了最优的机械结构尺寸。实际滤波器的实验结果验证了该方法的有效性。该方法可用于批量生产的腔体滤波器的计算机辅助制造系统中。     

基于自适应重要抽样的可靠性灵敏度分析方法

针对隐式极限状态方程的小失效概率问题,提出基于自适应重要抽样的可靠性灵敏度分析方法,给出该方法的具体实现步骤.所提方法从重要抽样抽取的所有样本点中选取合适的样本,利用回归分析和隐函数求导法则,求取失效概率对基本变量分布参数的灵敏度.所提算法的精度首先用有精确解的问题进行验证,然后在工程实例中进行应用.研究结果表明,与Monte Carlo可靠性灵敏度方法相比,所提方法具有计算精度相近但计算工作量小的优点,这种优点在失效概率小的情况下体现得更加充分.     

近红外光谱分析中建模样品优选方法的研究

结合牛奶成分近红外光谱测量系统的实例,在已定的浓度范围内针对牛奶中脂肪、蛋白质、乳糖三成分采用正交设计法优选参与建模的样品。研究中首次利用正交表的“正交性”原理优选建模样品,并针对牛奶中脂肪浓度的测量采用偏最小二乘(PLS)回归方法交互验证方式建立模型。在此基础上,将正交设计样品集与常规方法选择的样品集的脂肪PLS模型的预测结果进行了对比。实验结果表明：采用正交设计样品集与常规样品集分别建立的PLS模型的预测偏差之差低于0．02g／100g,上述两种方法PLS模型的实际预测浓度与参考浓度之差均集中在0.1g／100g,而后者样品数量约为前者的七倍。进一步的实验结果表明：从常规样品集的样品中随机抽取与正交设计样品集的样品数量相同的样品作为随机样品集并建模,其PLS模型的预测偏差高于常规方法的两倍、相关系数相对较低,并且其实际预测浓度与参考浓度之差集中在0．4g／100g。