• Title/Summary/Keyword: Huber's function

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Empirical Choice of the Shape Parameter for Robust Support Vector Machines

  • Pak, Ro-Jin
    • Communications for Statistical Applications and Methods
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    • v.15 no.4
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    • pp.543-549
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    • 2008
  • Inspired by using a robust loss function in the support vector machine regression to control training error and the idea of robust template matching with M-estimator, Chen (2004) applies M-estimator techniques to gaussian radial basis functions and form a new class of robust kernels for the support vector machines. We are specially interested in the shape of the Huber's M-estimator in this context and propose a way to find the shape parameter of the Huber's M-estimating function. For simplicity, only the two-class classification problem is considered.

A Method of Choosing a Value of the Bending Constant in Huber's M-Estimation Function

  • Park, Ro-Jin
    • Journal of the Korean Data and Information Science Society
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    • v.11 no.2
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    • pp.181-188
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    • 2000
  • The shape of an M-estimation function is generally determined in the sense of either/both maximizing efficiency of an M-estimator at the model or/and bounding the influence function of an M-estimator. We propose an empirical method of choosing a value of the bending constant in Huber's ${\psi}-function$, which is the most widely used M-estimation function when estimating the location parameter.

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Some efficient ratio-type exponential estimators using the Robust regression's Huber M-estimation function

  • Vinay Kumar Yadav;Shakti Prasad
    • Communications for Statistical Applications and Methods
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    • v.31 no.3
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    • pp.291-308
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    • 2024
  • The current article discusses ratio type exponential estimators for estimating the mean of a finite population in sample surveys. The estimators uses robust regression's Huber M-estimation function, and their bias as well as mean squared error expressions are derived. It was campared with Kadilar, Candan, and Cingi (Hacet J Math Stat, 36, 181-188, 2007) estimators. The circumstances under which the suggested estimators perform better than competing estimators are discussed. Five different population datasets with a well recognized outlier have been widely used in numerical and simulation-based research. These thorough studies seek to provide strong proof to back up our claims by carefully assessing and validating the theoretical results reported in our study. The estimators that have been proposed are intended to significantly improve both the efficiency and accuracy of estimating the mean of a finite population. As a result, the results that are obtained from statistical analyses will be more reliable and precise.

The Bending Constant in Huber’s Function in Terms of a Bandwidth in Density Estimator (HUBER의 M-추정함수의 조율상수와 커널추정함수의 평활계수의 관계)

  • 박노진
    • The Korean Journal of Applied Statistics
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    • v.14 no.2
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    • pp.357-367
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    • 2001
  • Huber의 M-추정함수의 형태는 조율상수가 주어질 때 비로소 그 형태가 결정된다. 조율상수를 커널밀도함수추정량의 평활계수를 이용하여 구하여 보았고, 모의실험을 통해 기존에 상요되는 조율상수들과 그 성능을 비교하여 보았다. 그 결과 새로운 방법에 의해 구해진 조율상수가 기존의 조율상수를 사용하는 경우 보다 모의실험을 통해 얻은 추정치의 분산이 작게되는 경우가 있음을 알았다.

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The Weight Function in BIRQ Estimator for the AR(1) Model with Additive Outliers

  • Jung Byoung Cheol;Han Sang Moon
    • Proceedings of the Korean Statistical Society Conference
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    • 2004.11a
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    • pp.129-134
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    • 2004
  • In this study, we investigate the effects of the weight function in the bounded influence regression quantile (BIRQ) estimator for the AR(1) model with additive outliers. In order to down-weight the outliers of X-axis, the Mallows' (1973) weight function has been commonly used in the BIRQ estimator. However, in our Monte Carlo study, the BIRQ estimator using the Tukey's bisquare weight function shows less MSE and bias than that of using the Mallows' weight function or Huber's weight function.

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A DOUBLY ROBUSTIFIED ESTIMATING FUNCTION FOR ARCH TIME SERIES MODELS

  • Kim, Sahm;Hwang, S.Y.
    • Journal of the Korean Statistical Society
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    • v.36 no.3
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    • pp.387-395
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    • 2007
  • We propose a doubly robustified estimating function for the estimation of parameters in the context of ARCH models. We investigate asymptotic properties of estimators obtained as solutions of robust estimating equations. A simulation study shows that robust estimator from specified doubly robustified estimating equation provides better performance than conventional robust estimators especially under heavy-tailed distributions of innovation errors.

The Weight Function in the Bounded Influence Regression Quantile Estimator for the AR(1) Model with Additive Outliers

  • Jung Byoung Cheol;Han Sang Moon
    • Communications for Statistical Applications and Methods
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    • v.12 no.1
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    • pp.169-179
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    • 2005
  • In this study, we investigate the effects of the weight function in the bounded influence regression quantile (BIRQ) estimator for the AR(l) model with additive outliers. In order to down-weight the outliers of X -axis, the Mallows' (1973) weight function has been commonly used in the BIRQ estimator. However, in our Monte Carlo study, the BIRQ estimator using the Tukey's bisquare weight function shows less MSE and bias than that of using the Mallows' weight function or Huber's weight function. Thus, the use of the Tukey's weight function is recommended in the BIRQ estimator for our model.

A Robust Heteroscadastic Test for ARCH Models

  • Kim, Sahm-Yeong
    • Journal of the Korean Data and Information Science Society
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    • v.15 no.2
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    • pp.441-447
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    • 2004
  • Li and Mak (1994) developed a test statistic for detecting the non-linearity and the heteroscedasticity of the time series data. But it is well known that the test statistic may be very sensitive in case of heavy-tailed distributions of the errors. Jiang et al.(2001) suggested the robust method for ARCH models but the calculation procedures for the estimation are very complicated. We suggested the robust method based on Huber's function and our method works quite well rater than the Li and Mak(1994). Also our method is relatively easy to calculate the test statistic.

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Negative Exponential Disparity Based Robust Estimates of Ordered Means in Normal Models

  • Bhattacharya, Bhaskar;Sarkar, Sahadeb;Jeong, Dong-Bin
    • Communications for Statistical Applications and Methods
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    • v.7 no.2
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    • pp.371-383
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    • 2000
  • Lindsay (1994) and Basu et al (1997) show that another density-based distance called the negative exponential disparity (NED) is an excellent competitor to the Hellinger distance (HD) in generating an asymptotically fully efficient and robust estimator. Bhattacharya and Basu (1996) consider estimation of the locations of several normal populations when an order relation between them is known to be true. They empirically show that the robust HD based weighted likelihood estimators compare favorably with the M-estimators based on Huber's $\psi$ function, the Gastworth estimator, and the trimmed mean estimator. In this paper we investigate the performance of the weighted likelihood estimator based on the NED as a robust alternative relative to that based on the HD. The NED based estimator is found to be quite competitive in the settings considered by Bhattacharya and Basu.

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Robust spectral estimator from M-estimation point of view: application to the Korean housing price index (M-추정에 기반을 둔 로버스트 스펙트럴 추정량: 주택 가격 지수에 대한 응용)

  • Pak, Ro Jin
    • The Korean Journal of Applied Statistics
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    • v.29 no.3
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    • pp.463-470
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    • 2016
  • In analysing a time series on the frequency domain, the spectral estimator (or periodogram) is a very useful statistic to identify the periods of a time series. However, the spectral estimator is very sensitive in nature to outliers, so that the spectral estimator in terms of M-estimation has been studied by some researchers. Pak (2001) proposed an empirical method to choose a tuning parameter for the Huber's M-estimating function. In this article, we try to implement Pak's estimation proposal in the spectral estimator. We use the Korean housing price index as an example data set for comparing various M-estimating results.