• 제목/요약/키워드: Weighted Least Squares

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DETECTION OF OUTLIERS IN WEIGHTED LEAST SQUARES REGRESSION

  • Shon, Bang-Yong;Kim, Guk-Boh
    • Journal of applied mathematics & informatics
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    • 제4권2호
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    • pp.501-512
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    • 1997
  • In multiple linear regression model we have presupposed assumptions (independence normality variance homogeneity and so on) on error term. When case weights are given because of variance heterogeneity we can estimate efficiently regression parameter using weighted least squares estimator. Unfortunately this estimator is sen-sitive to outliers like ordinary least squares estimator. Thus in this paper we proposed some statistics for detection of outliers in weighted least squares regression.

Asymmetric least squares regression estimation using weighted least squares support vector machine

  • Hwan, Chang-Ha
    • Journal of the Korean Data and Information Science Society
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    • 제22권5호
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    • pp.999-1005
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    • 2011
  • This paper proposes a weighted least squares support vector machine for asymmetric least squares regression. This method achieves nonlinear prediction power, while making no assumption on the underlying probability distributions. The cross validation function is introduced to choose optimal hyperparameters in the procedure. Experimental results are then presented which indicate the performance of the proposed model.

Robust inference for linear regression model based on weighted least squares

  • 박진표
    • Journal of the Korean Data and Information Science Society
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    • 제13권2호
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    • pp.271-284
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    • 2002
  • In this paper we consider the robust inference for the parameter of linear regression model based on weighted least squares. First we consider the sequential test of multiple outliers. Next we suggest the way to assign a weight to each observation $(x_i,\;y_i)$ and recommend the robust inference for linear model. Finally, to check the performance of confidence interval for the slope using proposed method, we conducted a Monte Carlo simulation and presented some numerical results and examples.

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Weighted Least Absolute Error Estimation of Regression Parameters

  • Song, Moon-Sup
    • Journal of the Korean Statistical Society
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    • 제8권1호
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    • pp.23-36
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    • 1979
  • In the multiple linear regression model a class of weighted least absolute error estimaters, which minimize the sum of weighted absolute residuals, is proposed. It is shown that the weighted least absolute error estimators with Wilcoxon scores are equivalent to the Koul's Wilcoxon type estimator. Therefore, the asymptotic efficiency of the proposed estimator with Wilcoxon scores relative to the least squares estimator is the same as the Pitman efficiency of the Wilcoxon test relative to the Student's t-test. To find the estimates the iterative weighted least squares method suggested by Schlossmacher is applicable.

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Preference Map using Weighted Regression

  • S.Y. Hwang;Jung, Su-Jin;Kim, Young-Won
    • Communications for Statistical Applications and Methods
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    • 제8권3호
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    • pp.651-659
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    • 2001
  • Preference map is a widely used graphical method for the preference data set which is frequently encountered in the field of marketing research. This provides joint configuration usually in two dimensional space between "products" and their "attributes". Whereas the classical preference map adopts the ordinary least squares method in deriving map, the present article suggests the weighted least squares approach providing the better graphical display and interpretation compared to the classical one. Internet search engine data in Korea are analysed for illustration.

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FWLS 적응 알고리듬을 이용한 시변 볼테라 시스템 식별 (Adaptive Identification of a Time-varying Volterra system using the FWLS (filtered weighted least squares) Algorithm)

  • 안규영;정인석;남상원
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2004년도 심포지엄 논문집 정보 및 제어부문
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    • pp.3-6
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    • 2004
  • In this paper, the problem of identifying a time-varying nonlinear system in an adaptive way was considered, whereby the time-varying second-order Volterra series was employed to model the system and the filtered weighted least squares (FWLS) algorithm was utilized for the fast parameter tracking capability with low computational burden. Finally, the performance of the proposed approach was demonstrated by providing some computer simulation results.

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Geographically weighted least squares-support vector machine

  • Hwang, Changha;Shim, Jooyong
    • Journal of the Korean Data and Information Science Society
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    • 제28권1호
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    • pp.227-235
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    • 2017
  • When the spatial information of each location is given specifically as coordinates it is popular to use the geographically weighted regression to incorporate the spatial information by assuming that the regression parameters vary spatially across locations. In this paper, we relax the linearity assumption of geographically weighted regression and propose a geographically weighted least squares-support vector machine for estimating geographically weighted mean by using the basic concept of kernel machines. Generalized cross validation function is induced for the model selection. Numerical studies with real datasets have been conducted to compare the performance of proposed method with other methods for predicting geographically weighted mean.

CONDITION NUMBERS WITH THEIR CONDITION NUMBERS FOR THE WEIGHTED MOORE-PENROSE INVERSE AND THE WEIGHTED LEAST SQUARES SOLUTION

  • Kang Wenhua;Xiang Hua
    • Journal of applied mathematics & informatics
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    • 제22권1_2호
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    • pp.95-112
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    • 2006
  • In this paper, the authors investigate the condition number with their condition numbers for weighted Moore-Penrose inverse and weighted least squares solution of min /Ax - b/M, where A is a rank-deficient complex matrix in $C^{m{\times}n} $ and b a vector of length m in $C^m$, x a vector of length n in $C^n$. For the normwise condition number, the sensitivity of the relative condition number itself is studied, the componentwise perturbation is also investigated.

가중최소제곱법에 의한 제1종 사영제곱합 (Type I projection sum of squares by weighted least squares)

  • 최재성
    • Journal of the Korean Data and Information Science Society
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    • 제25권2호
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    • pp.423-429
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    • 2014
  • 본 논문은 이원고정효과모형의 분산분석에서 오차의 독립성과 등분산성이 만족되지 않는 경우를 가정하고 있다. 자료분석을 위한 모수추정방법으로 가중최소제곱법을 가정하고 있으며 모수를 추정하기 위한 방법으로 모형의 순차적 적합방식을 이용하고 있다. 또한, 모형의 행렬표현식으로부터 벡터공간에서의 사영을 이용하여 자료를 분석하는 방법을 제시하고 있다. 모형의 순차적 적합에 해당하는 제1종 제곱합을 구하기 위하여 모형행렬에 의한 부분공간으로의 사영을 다루고 있다. 이 경우에 사영에 의한 제곱합을 사영제곱합으로 취급한다.

Statistical Estimation and Algorithm in Nonlinear Functions

  • Jea-Young Lee
    • Communications for Statistical Applications and Methods
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    • 제2권2호
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    • pp.135-145
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    • 1995
  • A new algorithm was given to successively fit the multiexponential function/nonlinear function to data by a weighted least squares method, using Gauss-Newton, Marquardt, gradient and DUD methods for convergence. This study also considers the problem of linear-nonlimear weighted least squares estimation which is based upon the usual Taylor's formula process.

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