• Title/Summary/Keyword: Squared bias

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A Comparative Study on Bayes Estimators for the Multivariate Normal Mcan

  • Kim, Dal-Ho;Lee, In suk;Kim, Hyun-Sook
    • Communications for Statistical Applications and Methods
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    • v.6 no.2
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    • pp.501-510
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    • 1999
  • In this paper, we consider a comparable study on three Bayes procedures for the multivariate normal mean estimation problem. In specific we consider hierarchical Bayes empirical Bayes and robust Bayes estimators for the normal means. Then three procedures are compared in terms of the four comparison criteria(i.e. Average Relative Bias (ARB) Average Squared Relative Bias (ASRB) Average Absolute Bias(AAB) Average Squared Deviation (ASD) using the real data set.

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Detection of a bias level in prediction errors due to input accelerations (입력 가속에서 비롯된 innovation 바이어스 레벨의 검출)

  • 신해곤;홍순목
    • 제어로봇시스템학회:학술대회논문집
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    • 1992.10a
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    • pp.554-557
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    • 1992
  • In this paper the normalized innovations squared of a Kalman filter is used to detect a bias level in prediction errors due to target accelerations. The probability density function of the normalized innovation squared is obtained for a steady state Kalman filter, and it is used to calculate the detection probability of the bias level. A typical example is given to compute the detection probability.

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Effect of Bias on the Pearson Chi-squared Test for Two Population Homogeneity Test

  • Heo, Sunyeong
    • Journal of Integrative Natural Science
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    • v.5 no.4
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    • pp.241-245
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    • 2012
  • Categorical data collected based on complex sample design is not proper for the standard Pearson multinomial-based chi-squared test because the observations are not independent and identically distributed. This study investigates effects of bias of point estimator of population proportion and its variance estimator to the standard Pearson chi-squared test statistics when the sample is collected based on complex sampling scheme. This study examines the effect under two population homogeneity test. The standard Pearson test statistic can be partitioned into two parts; the first part is the weighted sum of ${\chi}^2_1$ with eigenvalues of design matrix as their weights, and the additional second part which is added due to the biases of the point estimator and its variance estimator. Our empirical analysis shows that even though the bias of point estimator is small, Pearson test statistic is very much inflated due to underestimate the variance of point estimator. In the connection of design-based variance estimator and its design matrix, the bigger the average of eigenvalues of design matrix is, the larger relative size of which the first component part to Pearson test statistic is taking.

Selection of Data-adaptive Polynomial Order in Local Polynomial Nonparametric Regression

  • Jo, Jae-Keun
    • Communications for Statistical Applications and Methods
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    • v.4 no.1
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    • pp.177-183
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    • 1997
  • A data-adaptive order selection procedure is proposed for local polynomial nonparametric regression. For each given polynomial order, bias and variance are estimated and the adaptive polynomial order that has the smallest estimated mean squared error is selected locally at each location point. To estimate mean squared error, empirical bias estimate of Ruppert (1995) and local polynomial variance estimate of Ruppert, Wand, Wand, Holst and Hossjer (1995) are used. Since the proposed method does not require fitting polynomial model of order higher than the model order, it is simpler than the order selection method proposed by Fan and Gijbels (1995b).

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Estimation for scale parameter of type-I extreme value distribution

  • Choi, Byungjin
    • Journal of the Korean Data and Information Science Society
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    • v.26 no.2
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    • pp.535-545
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    • 2015
  • In a various range of applications including hydrology, the type-I extreme value distribution has been extensively used as a probabilistic model for analyzing extreme events. In this paper, we introduce methods for estimating the scale parameter of the type-I extreme value distribution. A simulation study is performed to compare the estimators in terms of mean-squared error and bias, and the obtained results are provided.

A Weighted Mean Squared Error Approach to Multiple Response Surface Optimization (다중반응표면 최적화를 위한 가중평균제곱오차)

  • Jeong, In-Jun;Cho, Hyun-Woo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.2
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    • pp.625-633
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    • 2013
  • Multiple response surface optimization (MRSO) aims at finding a setting of input variables which simultaneously optimizes multiple responses. The minimization of mean squared error (MSE), which consists of the squared bias and variance terms, is an effective way to consider the location and dispersion effects of the responses in MRSO. This approach basically assumes that both the terms have an equal weight. However, they need to be weighted differently depending on a problem situation, for example, in case that they are not of the same importance. This paper proposes to use the weighted MSE (WMSE) criterion instead of the MSE criterion in MRSO to consider an unequal weight situation.

Detection of a Bias Level in Prediction Errors due to Input Acceleration (입력 가속에서 비롯된 예측오차 바이어스 레벨의 검출)

  • Shin, Hae-Gon;Hong, Sun-Mog
    • Journal of Sensor Science and Technology
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    • v.2 no.1
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    • pp.57-64
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    • 1993
  • In this paper the normalized innovations squared of a Kalman filter is used to detect a bias level in prediction errors due to target accelerations. The probability density function of the normalized innovation squared is obtained for a steady state Kalman filter, and it is used to calculate the detection probability of the bias level. A typical example is given to compute the detection probability and to plot the maneuver detector operating characteristic curves.

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Improvement of Boundary Bias in Nonparametric Regression via Twicing Technique

  • Jo, Jae-Keun
    • Communications for Statistical Applications and Methods
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    • v.4 no.2
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    • pp.445-452
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    • 1997
  • In this paper, twicing technique for the improvement of asymptotic boundary bias in nonparametric regression is considered. Asymptotic mean squared errors of the nonparametric regression estimators are derived at the boundary region by twicing the Nadaraya-Waston and local linear smoothing. Asymptotic biases of the resulting estimators are of order$h^2$and$h^4$ respectively.

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Error cause analysis of Pearson test statistics for k-population homogeneity test (k-모집단 동질성검정에서 피어슨검정의 오차성분 분석에 관한 연구)

  • Heo, Sunyeong
    • Journal of the Korean Data and Information Science Society
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    • v.24 no.4
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    • pp.815-824
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    • 2013
  • Traditional Pearson chi-squared test is not appropriate for the data collected by the complex sample design. When one uses the traditional Pearson chi-squared test to the complex sample categorical data, it may give wrong test results, and the error may occur not only due to the biased variance estimators but also due to the biased point estimators of cell proportions. In this study, the design based consistent Wald test statistics was derived for k-population homogeneity test, and the traditional Pearson chi-squared test statistics was partitioned into three parts according to the causes of error; the error due to the bias of variance estimator, the error due to the bias of cell proportion estimator, and the unseparated error due to the both bias of variance estimator and bias of cell proportion estimator. An analysis was conducted for empirical results of the relative size of each error component to the Pearson chi-squared test statistics. The second year data from the fourth Korean national health and nutrition examination survey (KNHANES, IV-2) was used for the analysis. The empirical results show that the relative size of error from the bias of variance estimator was relatively larger than the size of error from the bias of cell proportion estimator, but its degrees were different variable by variable.

New Calibration Methods with Asymmetric Data

  • Kim, Sung-Su
    • The Korean Journal of Applied Statistics
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    • v.23 no.4
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    • pp.759-765
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    • 2010
  • In this paper, two new inverse regression methods are introduced. One is a distance based method, and the other is a likelihood based method. While a model is fitted by minimizing the sum of squared prediction errors of y's and x's in the classical and inverse methods, respectively. In the new distance based method, we simultaneously minimize the sum of both squared prediction errors. In the likelihood based method, we propose an inverse regression with Arnold-Beaver Skew Normal(ABSN) error distribution. Using the cross validation method with an asymmetric real data set, two new and two existing methods are studied based on the relative prediction bias(RBP) criteria.