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1.
职业院校学生自我认知满意度评价模型研究   总被引:1,自引:0,他引:1  
本文从职业院校学生自我认知的满意度模型参数估计方法应用情况入手,结合实例,分析了常用的传统回归方法的应用与主成分回归方法的优势互补方案,同时,简单地介绍了目前技术已经比较成熟的结构方程模型和偏最小二乘法的基本原理及其应用,并通过对几种参数估计方法的对比研究。指出在满意度研究过程中,应将多种参数估计方法结合起来使用,才能收到更好的效果。  相似文献   

2.
文章介绍了处理多元线性回归模型中多重共线性问题的有偏回归方法——岭回归和偏最小二乘回归,并通过实例比较了两种方法建立的回归方程的拟合效果,而偏最小二乘回归方法相对岭回归方法要更优.  相似文献   

3.
生物量是森林生态系统生产力的最好的指针,是森林生态系统结构优劣和功能高低的最直接的表现,是森林生态系统环境质量的综合体现.基于森林经理调查和偏最小二乘理论,联系计算生物量的模型现状,尝试了在切比雪夫(chebyshev)多项式的基础上基于MATLAB7.1平台建立偏最小二乘生物量模型,并通过其与传统生物量模型按照东北地区常见树种进行比较,得出偏最小二乘方法生物量模型计算生物量的精度更高.  相似文献   

4.
将偏最小二乘法(PLS)与可见分光光度法相结合,对胭脂红、苋菜红、日落黄三种食用色素进行不经分离的同时定量分析。使用交叉验证法选择主成分数建立了校正模型,预测结果令人满意。采用随机抽样方法研究了校正模型中样品集和样本容量对预测能力的影响,结果表明,在文章所研究的体系中,偏最小二乘法的预测能力不因样品集和样本容量的不同而有明显差异,从而说明了文章所用方法具有较大的可靠性和适用性。  相似文献   

5.
在经济变量模型的参数估计中,最常见的一种拟合方法就是经典的最小二乘法估计量.在给定的假设条件下,最小二乘法得到的参数估计量具有非常好的统计性质,能够直观的分析因变量与自变量之间存在的关系.对最小二乘法估计值求解的数学原理及计量性质进行了阐述,并采用最小二乘估计法估计量解释了影响个人所得税税收收入的一些主要因素.  相似文献   

6.
在经济变量模型的参数估计中,最常见的一种拟合方法就是经典的最小二乘法估计量.在给定的假设条件下,最小二乘法得到的参数估计量具有非常好的统计性质,能够直观的分析因变量与自变量之间存在的关系.对最小二乘法估计值求解的数学原理及计量性质进行了阐述,并采用最小二乘估计法估计量解释了影响个人所得税税收收入的一些主要因素.  相似文献   

7.
指出了利用偏最小二乘法解决成分数据回归问题的不足之处,提出了小离差主成分回归新模型,并给出了一个具体应用小离差主成分解决成分数据回归的例子。  相似文献   

8.
《河西学院学报》2017,(2):54-57
针对一类非线性系统建立精确机理模型困难、仅用单一模型构建软传感器不甚可靠等问题,提出一种基于数据驱动的多模型传感器构建方法,该方法利用数据驱动技术建立一类非线性系统RBF神经网络、最小二乘支持向量机和核部分最小二乘3种预测模型,用系统多个预测模型的融合值代替传感器的输出构建软传感器;最后将所提出的方法应用于一阶水箱液位控制系统,实验结果表明多模型软传感器预测输出和实际系统响应基本重合,说明多模型软传感器能为非线性系统建立准确的模型,对复杂工业过程的建模有一定的普适性.  相似文献   

9.
实验尝试采用近红外光谱法结合涡旋辅助液液微萃取技术,快速测定水中邻苯二甲酸二(2-乙基己基)酯(DEHP)残留.为提高检测的信噪比,使用四氯化碳作为萃取剂,不使用分散剂.近红外光谱数据采用偏最小二乘法分析,利用auto-scale对光谱进行预处理.偏最小二乘分析模型的主因子数为4,建模波段为4246.7~4424.1 cm-1.模型中RMSECV为0.3759,R2为0.9607.本实验结果显示了近红外方法结合涡旋辅助液液微萃取在分析环境水中的DEHP方面具有潜力.  相似文献   

10.
针对变压器油击穿电压在线测量困难,提出核主元分析(KPCA)和模糊C均值聚类(FCM)的变压器油击穿电压预测模型。首先,通过KPCA提取输人数据的非线性主元;然后采用FCM将提取的主元集分成具有不同聚类中心的子集,同时,采用差分进化算法对KPCA核参数和FCM聚类数寻优,分别为每一子集建立最小二乘支持向量机(LSSVM)子模型;最后通过子模型切换策略得到模型的最终输出。实验结果表明,提出的预测模型具有较好的泛化能力和预测精度。  相似文献   

11.
本文主要采用两种降维的方法和k-近邻法(KNN)有监督分类的方法来对基因芯片(微阵列)数据进行分析。PCA,PLS是一种提取海量的数据有效特征的有效方法,可以获得与原来基因芯片数据更为接近的成分的提取特征的效果。比较PCA降维方法和PLS降维方法对KNN统计判别分类的效果。  相似文献   

12.
本文主要采用主分量分析方法和二次判别分析(QDA)有监督分类的方法来对基因芯片(微阵列)数据进行分析.PCA是一种提取海量的数据有效特征的有效方法.可以获得与原来基因芯片数据更为接近的成分的提取特征的效果.实验表明采用PCA方法事先对数据处理不可以提高基因芯片数据分析的准确性.得出结论可为工业应用提供科学依据.  相似文献   

13.
Traditional studies on integrated statistical process control and engineering process control (SPC-EPC) are based on linear autoregressive integrated moving average (ARIMA) time series models to describe the dynamic noise of the system.However,linear models sometimes are unable to model complex nonlinear autocorrelation.To solve this problem,this paper presents an integrated SPC-EPC method based on smooth transition autoregressive (STAR) time series model,and builds a minimum mean squared error (MMSE) controller as well as an integrated SPC-EPC control system.The performance of this method for checking the trend and sustained shift is analyzed.The simulation results indicate that this integrated SPC-EPC control method based on STAR model is effective in controlling complex nonlinear systems.  相似文献   

14.
综述了多工序制造过程质量偏差流的主要研究方法,即状态空间建模方法和统计过程控制方法,评述了两种研究方法的建模思想、在过程监测和故障诊断方面的应用以及局限性。  相似文献   

15.
基于支持向量机的语音情感识别   总被引:6,自引:0,他引:6  
针对语音情感识别特征识别问题,本利用支持向量机进行了研究.分析表明语音信号的情感特征参数在输入空间中不完全是一个线性分类的问题,使用非线性的核函数对输入空间进行映射可以有效地提高识别效率.与已有的多模式语音情感识别方式相比,利用高斯(径向基)核函数的支持向量机的识别效果优于其他已有的方法.  相似文献   

16.
Progress monitoring using curriculum-based measures administered to a student at multiple points in time is common in educational settings. Recent research has demonstrated that common approaches to identifying individuals in need of special services, such as the trend line or median techniques, can be negatively impacted by the nonlinear change in scores over time. The purpose of this study was to test and demonstrate a nonlinear regression model for adjusting the linear trend line for the presence of such nonlinearities, thereby improving the accuracy of common methods for identifying students in need of special services. Results demonstrated that use of this nonlinear model improved the accuracy of common methods for identifying students in need of special services.  相似文献   

17.
Methods of statistical process control were briefly investigated in the field of educational measurement as early as 1999. However, only the use of a cumulative sum chart was explored. In this article other methods of statistical quality control are introduced and explored. In particular, methods in the form of Shewhart mean and standard deviation charts are introduced as techniques for ensuring quality in a measurement process for rating performance items in operational assessments. Several strengths and weaknesses of the procedures are explored with illustrative real and simulated rating data. Further research directions are also suggested .  相似文献   

18.
A multi-loop adaptive internal model control (IMC) strategy based on a dynamic partial least squares (PLS) framework is proposed to account for plant model errors caused by slow aging, drift in operational conditions, or environmental changes. Since PLS decomposition structure enables multi-loop controller design within latent spaces, a multivariable adaptive control scheme can be converted easily into several independent univariable control loops in the PLS space. In each latent subspace, once the model error exceeds a specific threshold, online adaptation rules are implemented separately to correct the plant model mismatch via a recursive least squares (RLS) algorithm. Because the IMC extracts the inverse of the minimum part of the internal model as its structure, the IMC controller is self-tuned by explicitly updating the parameters, which are parts of the internal model. Both parameter convergence and system stability are briefly analyzed, and proved to be effective. Finally, the proposed control scheme is tested and evaluated using a widely-used benchmark of a multi-input multi-output (MIMO) system with pure delay.  相似文献   

19.
The water distribution system of one residential district in Tianjin is taken as an example to analyze the changes of water quality. Partial least squares (PLS) regression model, in which the turbidity and Fe are regarded as con-trol objectives, is used to establish the statistical model. The experimental results indicate that the PLS regression model has good predicted results of water quality compared with the monitored data. The percentages of absolute relative error (below 15%, 20%, 30%) are 44.4%, 66.7%, 100% (turbidity) and 33.3%, 44.4%, 77.8% (Fe) on the 4th sampling point; 77.8%, 88.9%, 88.9% (turbidity) and 44.4%, 55.6%, 66.7% (Fe) on the 5th sampling point.  相似文献   

20.
Common factor analysis (FA) and principal component analysis (PCA) are commonly used to obtain lower-dimensional representations of matrices of correlations among manifest variables. Whereas some experts argue that differences in results from use of FA and PCA are small and relatively unimportant in empirical studies, the fundamental rationales for the two methods are very different. Here, FA and PCA are contrasted on four key issues: the range of possible dimensional loadings, the range of potential correlations among dimensions, the structure of residual covariances and correlations, and the relation between population parameters and the correlational structures with which they are associated. For decades, experts have emphasized indeterminacies of the FA model, particularly indeterminacy of common factor scores. Determinate in most respects, a heretofore unacknowledged, pernicious indeterminacy of PCA is demonstrated: the indeterminacy between PCA structural representations and the correlational structures from which they are derived. Researchers are often advised to use either FA or PCA in exploratory rounds of data analysis to understand and refine the dimensional structure of a domain before moving to Structural Equation Modeling in later theory-testing, confirmatory, replication studies. Results from the current study suggest that PCA is an unreliable method to use for such purposes and may lead to serious misrepresentation of the structure of a domain. Hence, PCA should never be used if the goal is to understand and represent the latent structure of a domain; only FA techniques should be used for this purpose, as only FA provides reliable structural representations as the basis for confirmatory tests in future studies.  相似文献   

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