In the operation and control of chemical processes, automatic data logging systems generate large volumes of data. It is important for supervising daily operation how to make use of the valuable information about norm...In the operation and control of chemical processes, automatic data logging systems generate large volumes of data. It is important for supervising daily operation how to make use of the valuable information about normal and abnormal operation, significant disturbance and changes in operational and control strategies. In this paper, principal component analysis(PCA)is clarified from the view of space, and every different subspace represents different operational mode and process performance. Based on that, the distance between two subspaces is calculated to evaluate the difference between them. The method is illustrated by a case study of a fluid catalytic cracking unit(FCCU) reactor-regenerator system.展开更多
Using the US National Aeronautics and space Administration （NASA） Earth Observing-1 Mission （EO-1） hyperion hyperspectral remote sensing data, we study the shallow-water bathymetry inversion in Smith Island Bay. T...Using the US National Aeronautics and space Administration （NASA） Earth Observing-1 Mission （EO-1） hyperion hyperspectral remote sensing data, we study the shallow-water bathymetry inversion in Smith Island Bay. The fast line-of-sight atmospheric analysis of spectral hypercubes module is applied for atmospheric correction, and principal component analysis method combined with scatter diagram and maximum likelihood classification is used for seabed classification. The diffuse attenuation coefficient Kd is derived using quasi-analytical algorithm （QAA）, which performs well in optically deep water. Kd obtained from QAA requires correction, particularly those derived in some coastal areas with optically shallow water and calculated by direct inversion based on radiative transfer theory to obtain the bathymetry. The direct inversion method derives the water depth quickly, and matches the results from optimized algorithm.展开更多
为解决轮盘形状优化过程中变量多且高度非线性的问题,建立了基于核主成分分析(Kernelized Principal Component Analysis,KPCA)技术的航空发动机轮盘优化方法。利用控制点形式的非均匀有理B样条(NURBS)曲线构造涡轮盘截面形状,以控制点...为解决轮盘形状优化过程中变量多且高度非线性的问题,建立了基于核主成分分析(Kernelized Principal Component Analysis,KPCA)技术的航空发动机轮盘优化方法。利用控制点形式的非均匀有理B样条(NURBS)曲线构造涡轮盘截面形状,以控制点的坐标作为设计变量;利用实验设计(DOE)进行采样,从中选取60个较优样本,计算核矩阵K,应用核矩阵K的特征向量计算投影向量的系数矩阵,采用投影后的变量作为新的设计变量,重构设计空间;最后,在降维后的设计空间中优化涡轮盘。结果表明:优化后轮心当量应力降低4.21%,周向应力降低0.26%,轮背径向应力降低1.58%,子午截面平均周向应力降低2.57%,圆柱截面平均径向应力降低6.51%。展开更多
文摘In the operation and control of chemical processes, automatic data logging systems generate large volumes of data. It is important for supervising daily operation how to make use of the valuable information about normal and abnormal operation, significant disturbance and changes in operational and control strategies. In this paper, principal component analysis(PCA)is clarified from the view of space, and every different subspace represents different operational mode and process performance. Based on that, the distance between two subspaces is calculated to evaluate the difference between them. The method is illustrated by a case study of a fluid catalytic cracking unit(FCCU) reactor-regenerator system.
基金supported by the Key Funds Programof the National Natural Science of China under Grant No. 60638020
文摘Using the US National Aeronautics and space Administration （NASA） Earth Observing-1 Mission （EO-1） hyperion hyperspectral remote sensing data, we study the shallow-water bathymetry inversion in Smith Island Bay. The fast line-of-sight atmospheric analysis of spectral hypercubes module is applied for atmospheric correction, and principal component analysis method combined with scatter diagram and maximum likelihood classification is used for seabed classification. The diffuse attenuation coefficient Kd is derived using quasi-analytical algorithm （QAA）, which performs well in optically deep water. Kd obtained from QAA requires correction, particularly those derived in some coastal areas with optically shallow water and calculated by direct inversion based on radiative transfer theory to obtain the bathymetry. The direct inversion method derives the water depth quickly, and matches the results from optimized algorithm.
文摘为解决轮盘形状优化过程中变量多且高度非线性的问题,建立了基于核主成分分析(Kernelized Principal Component Analysis,KPCA)技术的航空发动机轮盘优化方法。利用控制点形式的非均匀有理B样条(NURBS)曲线构造涡轮盘截面形状,以控制点的坐标作为设计变量;利用实验设计(DOE)进行采样,从中选取60个较优样本,计算核矩阵K,应用核矩阵K的特征向量计算投影向量的系数矩阵,采用投影后的变量作为新的设计变量,重构设计空间;最后,在降维后的设计空间中优化涡轮盘。结果表明:优化后轮心当量应力降低4.21%,周向应力降低0.26%,轮背径向应力降低1.58%,子午截面平均周向应力降低2.57%,圆柱截面平均径向应力降低6.51%。
