• 제목/요약/키워드: Nonparametric Statistics

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Improving Sample Entropy Based on Nonparametric Quantile Estimation

  • Park, Sang-Un;Park, Dong-Ryeon
    • Communications for Statistical Applications and Methods
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    • 제18권4호
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    • pp.457-465
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    • 2011
  • Sample entropy (Vasicek, 1976) has poor performance, and several nonparametric entropy estimators have been proposed as alternatives. In this paper, we consider a piecewise uniform density function based on quantiles, which enables us to evaluate entropy in each interval, and study the poor performance of the sample entropy in terms of the poor estimation of lower and upper quantiles. Then we propose some improved entropy estimators by simply modifying the quantile estimators, and compare their performances with some existing estimators.

ROBUST REGRESSION SMOOTHING FOR DEPENDENT OBSERVATIONS

  • Kim, Tae-Yoon;Song, Gyu-Moon;Kim, Jang-Han
    • 대한수학회논문집
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    • 제19권2호
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    • pp.345-354
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    • 2004
  • Boente and Fraiman [2] studied robust nonparametric estimators for regression or autoregression problems when the observations exhibit serial dependence. They established strong consistency of two families of M-type robust equivariant estimators for $\phi$-mixing processes. In this paper we extend their results to weaker $\alpha$$alpha$-mixing processes.

Nonparametric Reliability Estimation in Strength-Stress Model: B-Spline Approach

  • Kim, Jae-Joo;Na, Myung-Hwan;Lee, Kang-Hyun
    • 품질경영학회지
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    • 제27권2호
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    • pp.152-162
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    • 1999
  • In this paper we develope a new nonparametric estimator of the reliability in strength-stress model. This estimator is constructed using the maximum likelihood estimate of cumulative failure rate in the class of distributions which have piecewise linear failure rate functions between each pair of observations. Large sample properties of our estimator are examined. The proposed estimator is compared with previously known estimator by Monte Carlo study.

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Nonparametric Selection Procedures and Their Efficiency Comparisons

  • Sohn, Joong-K.;Shanti S.Gupta;Kim, Heon-Joo
    • Communications for Statistical Applications and Methods
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    • 제1권1호
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    • pp.41-51
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    • 1994
  • We consider nonparametric procedures for the selection and ranking problems. Tukey's generalized lambda distribution is condidered as the distribution for the score function because the distribution can approximate many well-known contionuous distributions. Also we compare these procedures in terms of efficiency, defined by the ratio of a probability of a correct selection divided by the expected selected subset size.

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Smooth Nonparametric Estimation of Mean Residual Life

  • Na, Myung-Hwan;Kim, Jae-Joo;Park, Sung-Hyun
    • 품질경영학회지
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    • 제27권1호
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    • pp.91-100
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    • 1999
  • In this paper we propose a smooth nonparametric estimator of mean residual life based on a complete sample. This estimator is constructed using the maximum likelihood estimate of cumulative failure rate in the class of distributions which have piecewise linear failure rate functions between each pair of observations. We derive the asymptotic properties of our estimator. Examples using simulated data are used to illustrate the performance of this estimation.

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Stationary Bootstrapping for the Nonparametric AR-ARCH Model

  • Shin, Dong Wan;Hwang, Eunju
    • Communications for Statistical Applications and Methods
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    • 제22권5호
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    • pp.463-473
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    • 2015
  • We consider a nonparametric AR(1) model with nonparametric ARCH(1) errors. In order to estimate the unknown function of the ARCH part, we apply the stationary bootstrap procedure, which is characterized by geometrically distributed random length of bootstrap blocks and has the advantage of capturing the dependence structure of the original data. The proposed method is composed of four steps: the first step estimates the AR part by a typical kernel smoothing to calculate AR residuals, the second step estimates the ARCH part via the Nadaraya-Watson kernel from the AR residuals to compute ARCH residuals, the third step applies the stationary bootstrap procedure to the ARCH residuals, and the fourth step defines the stationary bootstrapped Nadaraya-Watson estimator for the ARCH function with the stationary bootstrapped residuals. We prove the asymptotic validity of the stationary bootstrap estimator for the unknown ARCH function by showing the same limiting distribution as the Nadaraya-Watson estimator in the second step.

Depth-Based rank test for multivariate two-sample scale problem

  • Digambar Tukaram Shirke;Swapnil Dattatray Khorate
    • Communications for Statistical Applications and Methods
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    • 제30권3호
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    • pp.227-244
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    • 2023
  • In this paper, a depth-based nonparametric test for a multivariate two-sample scale problem is proposed. The proposed test statistic is based on the depth-induced ranks and is thus distribution-free. In this article, the depth values of data points of one sample are calculated with respect to the other sample or distribution and vice versa. A comprehensive simulation study is used to examine the performance of the proposed test for symmetric as well as skewed distributions. Comparison of the proposed test with the existing depth-based nonparametric tests is accomplished through empirical powers over different depth functions. The simulation study admits that the proposed test outperforms existing nonparametric depth-based tests for symmetric and skewed distributions. Finally, an actual life data set is used to demonstrate the applicability of the proposed test.

A Nonparametric Bootstrap Test and Estimation for Change

  • Kim, Jae-Hee
    • Communications for Statistical Applications and Methods
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    • 제14권2호
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    • pp.443-457
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    • 2007
  • This paper deals with the problem of testing the existence of change in mean and estimating the change-point using nonparametric bootstrap technique. A test statistic using Gombay and Horvath (1990)'s functional form is applied to derive a test statistic and nonparametric change-point estimator with bootstrapping idea. Achieved significance level of the test is calculated for the proposed test to show the evidence against the null hypothesis. MSE and percentiles of the bootstrap change-point estimators are given to show the distribution of the proposed estimator in simulation.

A Nonparametric Additive Risk Model Based on Splines

  • Park, Cheol-Yong
    • Journal of the Korean Data and Information Science Society
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    • 제18권1호
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    • pp.97-105
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    • 2007
  • We consider a nonparametric additive risk model that is based on splines. This model consists of both purely and smoothly nonparametric components. As an estimation method of this model, we use the weighted least square estimation by Huller and Mckeague (1991). We provide an illustrative example as well as a simulation study that compares the performance of our method with the ordinary least square method.

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A Nonparametric Additive Risk Model Based On Splines

  • 박철용
    • 한국데이터정보과학회:학술대회논문집
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    • 한국데이터정보과학회 2006년도 추계 학술발표회 논문집
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    • pp.49-50
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    • 2006
  • We consider a nonparametric additive risk model that are based on splines. This model consists of both purely and smoothly nonparametric components. As an estimation method of this model, we use the weighted least square estimation by Huffer and McKeague (1991). We provide an illustrative example as well as a simulation study that compares the performance of our method with the ordinary least square method.

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