• Title/Summary/Keyword: randomly right censoring

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Two-step LS-SVR for censored regression

  • Bae, Jong-Sig;Hwang, Chang-Ha;Shim, Joo-Yong
    • Journal of the Korean Data and Information Science Society
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    • v.23 no.2
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    • pp.393-401
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    • 2012
  • This paper deals with the estimations of the least squares support vector regression when the responses are subject to randomly right censoring. The estimation is performed via two steps - the ordinary least squares support vector regression and the least squares support vector regression with censored data. We use the empirical fact that the estimated regression functions subject to randomly right censoring are close to the true regression functions than the observed failure times subject to randomly right censoring. The hyper-parameters of model which affect the performance of the proposed procedure are selected by a generalized cross validation function. Experimental results are then presented which indicate the performance of the proposed procedure.

Kernel Ridge Regression with Randomly Right Censored Data

  • Shim, Joo-Yong;Seok, Kyung-Ha
    • Communications for Statistical Applications and Methods
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    • v.15 no.2
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    • pp.205-211
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    • 2008
  • This paper deals with the estimations of kernel ridge regression when the responses are subject to randomly right censoring. The iterative reweighted least squares(IRWLS) procedure is employed to treat censored observations. The hyperparameters of model which affect the performance of the proposed procedure are selected by a generalized cross validation(GCV) function. Experimental results are then presented which indicate the performance of the proposed procedure.

Censored Kernel Ridge Regression

  • Shim, Joo-Yong
    • Journal of the Korean Data and Information Science Society
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    • v.16 no.4
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    • pp.1045-1052
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    • 2005
  • This paper deals with the estimations of kernel ridge regression when the responses are subject to randomly right censoring. The weighted data are formed by redistributing the weights of the censored data to the uncensored data. Then kernel ridge regression can be taken up with the weighted data. The hyperparameters of model which affect the performance of the proposed procedure are selected by a generalized approximate cross validation(GACV) function. Experimental results are then presented which indicate the performance of the proposed procedure.

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Weighted LS-SVM Regression for Right Censored Data

  • Kim, Dae-Hak;Jeong, Hyeong-Chul
    • Communications for Statistical Applications and Methods
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    • v.13 no.3
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    • pp.765-776
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    • 2006
  • In this paper we propose an estimation method on the regression model with randomly censored observations of the training data set. The weighted least squares support vector machine regression is applied for the regression function estimation by incorporating the weights assessed upon each observation in the optimization problem. Numerical examples are given to show the performance of the proposed estimation method.

Mixed effects least squares support vector machine for survival data analysis (생존자료분석을 위한 혼합효과 최소제곱 서포트벡터기계)

  • Hwang, Chang-Ha;Shim, Joo-Yong
    • Journal of the Korean Data and Information Science Society
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    • v.23 no.4
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    • pp.739-748
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    • 2012
  • In this paper we propose a mixed effects least squares support vector machine (LS-SVM) for the censored data which are observed from different groups. We use weights by which the randomly right censoring is taken into account in the nonlinear regression. The weights are formed with Kaplan-Meier estimates of censoring distribution. In the proposed model a random effects term representing inter-group variation is included. Furthermore generalized cross validation function is proposed for the selection of the optimal values of hyper-parameters. Experimental results are then presented which indicate the performance of the proposed LS-SVM by comparing with a standard LS-SVM for the censored data.

Iterative Support Vector Quantile Regression for Censored Data

  • Shim, Joo-Yong;Hong, Dug-Hun;Kim, Dal-Ho;Hwang, Chang-Ha
    • Communications for Statistical Applications and Methods
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    • v.14 no.1
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    • pp.195-203
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    • 2007
  • In this paper we propose support vector quantile regression (SVQR) for randomly right censored data. The proposed procedure basically utilizes iterative method based on the empirical distribution functions of the censored times and the sample quantiles of the observed variables, and applies support vector regression for the estimation of the quantile function. Experimental results we then presented to indicate the performance of the proposed procedure.