• Title, Summary, Keyword: principal component analysis (PCA)

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Nonlinear Feature Extraction using Class-augmented Kernel PCA (클래스가 부가된 커널 주성분분석을 이용한 비선형 특징추출)

  • Park, Myoung-Soo;Oh, Sang-Rok
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.48 no.5
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    • pp.7-12
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    • 2011
  • In this papwer, we propose a new feature extraction method, named as Class-augmented Kernel Principal Component Analysis (CA-KPCA), which can extract nonlinear features for classification. Among the subspace method that was being widely used for feature extraction, Class-augmented Principal Component Analysis (CA-PCA) is a recently one that can extract features for a accurate classification without computational difficulties of other methods such as Linear Discriminant Analysis (LDA). However, the features extracted by CA-PCA is still restricted to be in a linear subspace of the original data space, which limites the use of this method for various problems requiring nonlinear features. To resolve this limitation, we apply a kernel trick to develop a new version of CA-PCA to extract nonlinear features, and evaluate its performance by experiments using data sets in the UCI Machine Learning Repository.

ECG based Personal Authentication using Principal Component Analysis (주성분 분석기법을 이용한 심전도 기반 개인인증)

  • Cho, Ju-Hee;Cho, Byeong-Jun;Lee, Dae-Jong;Chun, Myung-Geun
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.66 no.4
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    • pp.258-262
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    • 2017
  • The PCA(Principal Component Analysis) algorithm is widely used as a technique of expressing the eigenvectors of the covariance matrix that best represents the characteristics of the data and reducing the high dimensional vector to a low dimensional vector. In this paper, we have developed a personal authentication method based on ECG using principal component analysis. The proposed method showed excellent recognition performance of 98.2 [%] when it was experimented using electrocardiogram data obtained at weekly intervals. Therefore, it can be seen that it is useful for personal authentication by reducing the dimension without changing the information on the variability and the correlation set variable existing in the electrocardiogram data by using the principal component analysis technique.

LMS and LTS-type Alternatives to Classical Principal Component Analysis

  • Huh, Myung-Hoe;Lee, Yong-Goo
    • Communications for Statistical Applications and Methods
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    • v.13 no.2
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    • pp.233-241
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    • 2006
  • Classical principal component analysis (PCA) can be formulated as finding the linear subspace that best accommodates multidimensional data points in the sense that the sum of squared residual distances is minimized. As alternatives to such LS (least squares) fitting approach, we produce LMS (least median of squares) and LTS (least trimmed squares)-type PCA by minimizing the median of squared residual distances and the trimmed sum of squares, in a similar fashion to Rousseeuw (1984)'s alternative approaches to LS linear regression. Proposed methods adopt the data-driven optimization algorithm of Croux and Ruiz-Gazen (1996, 2005) that is conceptually simple and computationally practical. Numerical examples are given.

A study on the properties of sensitivity analysis in principal component regression and latent root regression (주성분회귀와 고유값회귀에 대한 감도분석의 성질에 대한 연구)

  • Shin, Jae-Kyoung;Chang, Duk-Joon
    • Journal of the Korean Data and Information Science Society
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    • v.20 no.2
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    • pp.321-328
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    • 2009
  • In regression analysis, the ordinary least squares estimates of regression coefficients become poor, when the correlations among predictor variables are high. This phenomenon, which is called multicollinearity, causes serious problems in actual data analysis. To overcome this multicollinearity, many methods have been proposed. Ridge regression, shrinkage estimators and methods based on principal component analysis (PCA) such as principal component regression (PCR) and latent root regression (LRR). In the last decade, many statisticians discussed sensitivity analysis (SA) in ordinary multiple regression and same topic in PCR, LRR and logistic principal component regression (LPCR). In those methods PCA plays important role. Many statisticians discussed SA in PCA and related multivariate methods. We introduce the method of PCR and LRR. We also introduce the methods of SA in PCR and LRR, and discuss the properties of SA in PCR and LRR.

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Real-Time Small Exposed Area $SiO_2$ Films Thickness Monitoring in Plasma Etching Using Plasma Impedance Monitoring with Modified Principal Component Analysis

  • Jang, Hae-Gyu;Nam, Jae-Uk;Chae, Hui-Yeop
    • Proceedings of the Korean Vacuum Society Conference
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    • pp.320-320
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    • 2013
  • Film thickness monitoring with plasma impedance monitoring (PIM) is demonstrated for small area $SiO_2$ RF plasma etching processes in this work. The chamber conditions were monitored by the impedance signal variation from the I-V monitoring system. Moreover, modified principal component analysis (mPCA) was applied to estimate the $SiO_2$ film thickness. For verification, the PIM was compared with optical emission spectroscopy (OES) signals which are widely used in the semiconductor industry. The results indicated that film thickness can be estimated by 1st principal component (PC) and 2nd PC. Film thickness monitoring of small area $SiO_2$ etching was successfully demonstrated with RF plasma harmonic impedance monitoring and mPCA. We believe that this technique can be potentially applied to plasma etching processes as a sensitive process monitoring tool.

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Principal component analysis in the frequency domain: a review and their application to climate data (주파수공간에서의 주성분분석: 리뷰와 기상자료에의 적용)

  • Jo, You-Jung;Oh, Hee-Seok;Lim, Yaeji
    • The Korean Journal of Applied Statistics
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    • v.30 no.3
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    • pp.441-451
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    • 2017
  • In this paper, we review principal component analysis (PCA) procedures in the frequency domain and apply them to analyze sea surface temperature data. The classical PCA defined in the time domain is a popular dimension reduction technique. Extending the conventional PCA to the frequency domain makes it possible to define PCA in the frequency domain, which is useful for dimension reduction as well as a feature extraction of multiple time series. We focus on two PCA methods in the frequency domain, Hilbert PCA (HPCA) and frequency domain PCA (FDPCA). We review these two PCAs in order for potential readers to easily understand insights as well as perform a numerical study for comparison with conventional PCA. Furthermore, we apply PCA methods in the frequency domain to sea surface temperature data on the tropical Pacific Ocean. Results from numerical experiments demonstrate that PCA in the frequency domain is effective for the analysis of time series data.

A Study on artifact extraction in magnetocardiography using multilayer neural network and principal component analysis (신경망과 주성분 분석을 이용한 심자도 신호에서 Artifact 추출)

  • Lee D. H.;Kim T. Y.;Lee D. J.
    • 한국컴퓨터산업교육학회:학술대회논문집
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    • pp.59-64
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    • 2003
  • Principal component analysis(PCA) and neural network(NN) are used in reducing external noise in magnetocadiography. The PCA technique turns out to be very effective in reducing pulse noise in some SQUID channels and the NN find noise component automatically. Some experimental results obtained from 61 channel MCG system are shown.

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Modified Recursive PC (수정된 반복 주성분 분석 기법에 대한 연구)

  • Kim, Dong-Gyu;Kim, Ah-Hyoun;Kim, Hyun-Joong
    • The Korean Journal of Applied Statistics
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    • v.24 no.5
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    • pp.963-977
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    • 2011
  • PCA(Principal Component Analysis) is a well-studied statistical technique and an important tool for handling multivariate data. Although many algorithms exist for PCA, most of them are unsuitable for real time applications or high dimensional problems. Since it is desirable to avoid extensive matrix operations in such cases, alternative solutions are required to calculate the eigenvalues and eigenvectors of the sample covariance matrix. Erdogmus et al. (2004) proposed Recursive PCA(RPCA), which is a fast adaptive on-line solution for PCA, based on the first order perturbation theory. It facilitates the real-time implementation of PCA by recursively approximating updated eigenvalues and eigenvectors. However, the performance of the RPCA method becomes questionable as the size of newly-added data increases. In this paper, we modified the RPCA method by taking advantage of the mathematical relation of eigenvalues and eigenvectors of sample covariance matrix. We compared the performance of the proposed algorithm with that of RPCA, and found that the accuracy of the proposed method remarkably improved.

An eigenspace projection clustering method for structural damage detection

  • Zhu, Jun-Hua;Yu, Ling;Yu, Li-Li
    • Structural Engineering and Mechanics
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    • v.44 no.2
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    • pp.179-196
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    • 2012
  • An eigenspace projection clustering method is proposed for structural damage detection by combining projection algorithm and fuzzy clustering technique. The integrated procedure includes data selection, data normalization, projection, damage feature extraction, and clustering algorithm to structural damage assessment. The frequency response functions (FRFs) of the healthy and the damaged structure are used as initial data, median values of the projections are considered as damage features, and the fuzzy c-means (FCM) algorithm are used to categorize these features. The performance of the proposed method has been validated using a three-story frame structure built and tested by Los Alamos National Laboratory, USA. Two projection algorithms, namely principal component analysis (PCA) and kernel principal component analysis (KPCA), are compared for better extraction of damage features, further six kinds of distances adopted in FCM process are studied and discussed. The illustrated results reveal that the distance selection depends on the distribution of features. For the optimal choice of projections, it is recommended that the Cosine distance is used for the PCA while the Seuclidean distance and the Cityblock distance suitably used for the KPCA. The PCA method is recommended when a large amount of data need to be processed due to its higher correct decisions and less computational costs.

Predicting concrete properties using neural networks (NN) with principal component analysis (PCA) technique

  • Boukhatem, B.;Kenai, S.;Hamou, A.T.;Ziou, Dj.;Ghrici, M.
    • Computers and Concrete
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    • v.10 no.6
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    • pp.557-573
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    • 2012
  • This paper discusses the combined application of two different techniques, Neural Networks (NN) and Principal Component Analysis (PCA), for improved prediction of concrete properties. The combination of these approaches allowed the development of six neural networks models for predicting slump and compressive strength of concrete with mineral additives such as blast furnace slag, fly ash and silica fume. The Back-Propagation Multi-Layer Perceptron (BPMLP) with Bayesian regularization was used in all these models. They are produced to implement the complex nonlinear relationship between the inputs and the output of the network. They are also established through the incorporation of a huge experimental database on concrete organized in the form Mix-Property. Thus, the data comprising the concrete mixtures are much correlated to each others. The PCA is proposed for the compression and the elimination of the correlation between these data. After applying the PCA, the uncorrelated data were used to train the six models. The predictive results of these models were compared with the actual experimental trials. The results showed that the elimination of the correlation between the input parameters using PCA improved the predictive generalisation performance models with smaller architectures and dimensionality reduction. This study showed also that using the developed models for numerical investigations on the parameters affecting the properties of concrete is promising.