基于ICA_FNN的软传感器建模过程原始特征选择

针对软传感器建模过程中辅助变量通常是多因素的混杂信号,在原始特征空间很难进行原始特征约简的问题,提出一种结合独立成分分析(ICA)和虚假最近邻点法(FNN)的原始特征选择法.利用独立成分分析法(ICA)将原始特征空间的混杂信号映射到新的独立特征子空间；然后再利用FNN计算每个原始特征剔除前后在独立特征子空间里的相似性测度,进而判断它对主导变量的影响能力,由此选择出原始特征.仿真结果表明,该方法具有优秀的原始特征选择能力.因此,该研究为选择出软传感器模型的原始特征提供了新方法.     

基于KPCA子空间虚假邻点判别的非线性建模的变量选择

特征变量选择技术是非线性系统建模过程中降低信息冗余和提高精度的有效方法。提出一种结合核主成分分析法(Kernel principal components analysis,KPCA)与虚假最近邻点法(False nearest neighbor,FNN)的变量选择法。引入核方法,将非线性原始数据映射到线性空间,再采用主成分分析法有效合理地消除因子之间的多重共线性,受混沌相空间虚假最近邻点法的启示,通过计算原始数据在KPCA子空间中投影的距离,判断其对主导变量的解释能力,由此进行变量的选择该方法用氢氰酸生产工艺工程中的非线性模型验证,并与全参数模型进行比较,结果显示该方法有良好的变量选择能力。因此,该研究为非线性系统建模的变量选择方法提供一种新方法。     

基于特征子空间虚假邻点判别的软传感器模型变量选择

辅助变量选择技术是软传感器建模过程中降低信息冗余和提高效率的有效方法.提出一种结合偏最小二乘回归法与虚假最近邻法的变量选择法.采用偏最小二乘回归法有效合理地消除因子之间的多重共线性,在一个新的正交空间里,受混沌相空间虚假最近邻点法的启示,通过计算某变量选择前后在特征子空间里的相关性,判断其对主导变量的解释能力,由此进行变量的选择,利用偏最小二乘法得到软测量模型.该方法通过构造的试验和Jolliff变量选择试验作了验证,结果显示该方法有良好的辅助变量选择能力,为软传感器建模的辅助变量选择方法提供了一种新方法.     

基于KCCA虚假邻点判别的非线性变量选择

特征变量选择技术是非线性系统建模过程中降低信息冗余和提高精度的有效方法。提出一种结合核典型相关法(kernel canonical correlation analysis,KCCA)与虚假最近邻法的变量选择法。首先引入核方法,将非线性原始数据映射到线性空间,再采用典型相关法有效合理地消除因子之间的多重共线性,受混沌相空间虚假最近邻点法的启示,通过计算原始数据在KCCA子空间中投影的距离,判断其对主导变量的解释能力,由此进行变量的选择。该方法用氢氰酸生产工艺工程中的非线性模型验证,并与全参数模型进行比较,结果显示该方法有良好的变量选择能力。因此,该研究为非线性系统建模的变量选择方法提供了一种新方法。     

K-OPLS方法在化工软测量建模中的应用

针对强非线性复杂化工过程的软测量建模问题,提出了一种基于核隐变量正交投影(K-OPLS)的建模方法。隐变量正交投影(O-PLS)是一种通用的线性多变量数据建模方法,它可以消除与响应变量(输出)正交的描述变量(输入)的总体变化。在O-PLS模型框架下, K-OPLS方法利用"核技巧"将描述变量映射到高维特征空间,计算模型中的预测成分和响应-正交成分。因此, K-OPLS方法通过给出描述与响应变量之间的非线性关系,在一定程度上提高了模型的性能,增强了模型的可解释性。为了验证K-OPLS方法的有效性,将其分别应用于脱丁烷塔基丁烷(C4)组分含量估计、工业流化催化裂化装置(FCCU)关键产品产量预测、硫回收装置(SRU)中H_2S和SO_2浓度预测的软测量建模实例中。实验结果表明,在相同条件下,与支持向量机(SVM)、最小二乘支持向量机(LSSVM)、主元分析-支持向量机(PCA-SVM)、极限学习机(ELM)、核极限学习机(KELM)和PCA-KELM方法相比较, K-OPLS方法具有更好的建模精度和模型泛化能力。     

K-OPLS方法在化工软测量建模中的应用（英文）

针对强非线性复杂化工过程的软测量建模问题,提出了一种基于核隐变量正交投影(K-OPLS)的建模方法。隐变量正交投影(O-PLS)是一种通用的线性多变量数据建模方法,它可以消除与响应变量(输出)正交的描述变量(输入)的总体变化。在O-PLS模型框架下, K-OPLS方法利用"核技巧"将描述变量映射到高维特征空间,计算模型中的预测成分和响应-正交成分。因此, K-OPLS方法通过给出描述与响应变量之间的非线性关系,在一定程度上提高了模型的性能,增强了模型的可解释性。为了验证K-OPLS方法的有效性,将其分别应用于脱丁烷塔基丁烷(C4)组分含量估计、工业流化催化裂化装置(FCCU)关键产品产量预测、硫回收装置(SRU)中H_2S和SO_2浓度预测的软测量建模实例中。实验结果表明,在相同条件下,与支持向量机(SVM)、最小二乘支持向量机(LSSVM)、主元分析-支持向量机(PCA-SVM)、极限学习机(ELM)、核极限学习机(KELM)和PCA-KELM方法相比较, K-OPLS方法具有更好的建模精度和模型泛化能力。     

基于监督保局子空间虚假近邻准则的原始特征选择

提出一种基于监督保局投影(SLPP)与虚假最近邻(FNN)准则的原始特征选择方法。该方法首先将非线性原始数据映射到监督保局子空间,消除样本数据输入变量之间的相关性;然后,利用虚假近邻点方法计算剔除每个原始特征前后输入样本在监督保局子空间里的相似性测度,获得每个原始特征对类别变量不同程度的解释力;最后,从全特征开始逐步剔除解释能力弱的特征进而获得多组特征子集,并建立最近邻分类器,识别率最高且含特征数最少的特征子集即为最优特征子集。采用合成数据对该方法进行了仿真验证,结果表明,该方法可获得与数据集本质分类特征吻合的最佳特征子集。将该方法应用于选择真实的低阻油气层特征,获得的最佳特征子集比全特征集合的特征数量减少了50%以上,分类识别率高出8%。结果显示该方法具有优秀的原始特征选择能力,是一种有效的非线性特征选择方法。     

基于特征子空间虚假邻点判别的铝电解槽况诊断模型

造成铝电解异常槽况的因素较多,彼此相关性强,建立槽况诊断模型时计算量巨大。利用核主元分析法虽然可以对非线性数据进行降维,但得到的主元仍然是原始变量在特征空间的线性组合,既无明确的物理含义,又无法对原始特征进行约简达到减少传感器种类的目的。提出一种基于特征子空间虚假邻点判别的槽况诊断方法,首先考察各原始变量置零前后在核空间主元投影上的相似度,根据其对槽况的解释能力进行原始变量选择;再将约简后的原始变量输入概率神经网络,对各类异常槽况进行诊断。通过取自某厂170KA大型预焙槽的268组样本进行检验:在原始特征约简44.4%的情况下分类精度达到95%以上,表明该方法不但可对原始特征进行有效约简,而且槽况分类精度和训练时间均优于同类模型。     

一种新的基于MKPLS的间歇过程质量预测方法

传统MKPLS方法在进行核技巧计算时需要对全部的测量变量进行两两运算,造成了运算量过大、存储空间需求高的问题。针对间歇过程在在线质量预测方面的非线性问题以及计算量的问题,提出一种新的基于特征空间(FS)的核偏最小二乘算法,用于对间歇过程的质量数据进行在线软测量。首先,算法将间歇过程采集到的数据进行三维展开及标准化处理;之后,将这些数据进行特征向量提取以降低投影到核空间中的数据量以及计算量;最后,针对传统特征向量提取算法在向量选择顺序方面的盲目性,将质量数据纳入考量,构建一种新的特征向量提取方式,以解决在线软测量方面的非线性问题,进一步提高在线软测量精度。最后将提出的算法用于青霉素发酵仿真及实际过程的在线监测,验证了方法的有效性。     

基于核独立元分析的工业故障检测

独立元分析(ICA)是从多个源信号的线性混合中分离出源信号的技术,是一种基于信号高阶统计特性的算法。但对于处理非线性变化信号有一定的局限,核独立元分析(KICA)方法能够很好地解决这个问题,该方法主要结合了核主元分析(KPCA)和独立元分析(ICA)的优点,是在线故障检测的一种非线性算法。该算法利用工业过程中多仪表在正常工作下的历史数据建立故障检测模型,通过监控检测统计量是否超出阀值控制限来进行故障检测。使用TE(Tennessee Eastman)过程数据进行仿真来验证此算法的有效性。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

Fifth International Summer School on Screw-Theory Based Methods in Robotics

正3-11 September,2014University of Bologna,Bologna,Italy www.summerscrews.org summerscrews2014.ing.unibo.it SUMMER 20SCREWS 14In 2014,our screw-theory school comes to the world's oldest university.In early September,Summer Screws'14 will gather six experts in the application of screw theory in robotics and up to 40 participants at the University of Bologna,Bologna,Italy.The school will teach attendees how to apply existing methods and empower them to develop new ones in their own research.The basic theoretical notions will be introduced in a rigorous manner,emphasizing examples,applications,and exercises.Scholarships are available.     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

INDUSTRIAL ENGINEERING AND VISUALISATION-A PRODUCT DEVELOPMENT PERSPECTIVE

Taking the actual project of teaching and researching process for example, the relationship between the industrial engineering and product development is discussed. And use the novel visualization technology to support the industrial engineering and product development. How to use the new computer modeling and simulating technologies to support the product development and industrial engineering, is introduced especially. The support includes both domestic products and industrial systems. The visualization and computer technologies take a very important role in some system or multi-direction modeling, those technologies mentioned above can help the industrial engineers study the effect of design on the whole life circle, including the producing steps. So the engineers can avoid making the wrong decision which may cause bad effects on the whole industrial engineering.