• Title/Summary/Keyword: multiple change-points

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Bayesian Multiple Change-Point Estimation and Segmentation

  • Kim, Jaehee;Cheon, Sooyoung
    • Communications for Statistical Applications and Methods
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    • v.20 no.6
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    • pp.439-454
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    • 2013
  • This study presents a Bayesian multiple change-point detection approach to segment and classify the observations that no longer come from an initial population after a certain time. Inferences are based on the multiple change-points in a sequence of random variables where the probability distribution changes. Bayesian multiple change-point estimation is classifies each observation into a segment. We use a truncated Poisson distribution for the number of change-points and conjugate prior for the exponential family distributions. The Bayesian method can lead the unsupervised classification of discrete, continuous variables and multivariate vectors based on latent class models; therefore, the solution for change-points corresponds to the stochastic partitions of observed data. We demonstrate segmentation with real data.

A Bayesian time series model with multiple structural change-points for electricity data

  • Kim, Jaehee
    • Journal of the Korean Data and Information Science Society
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    • v.28 no.4
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    • pp.889-898
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    • 2017
  • In this research multiple change-points estimation for South Korean electricity generation data is considered. We analyze the South Korean electricity data via deterministically trending dynamic time series model with multiple structural changes in trends in a Bayesian approach. The number of change-points and the timing are unknown. The goal is to find the best model with the appropriate number of change-points and the length of the segments. A genetic algorithm is implemented to solve this optimization problem with a variable dimension of parameters. We estimate the structural change-points for South Korean electricity generation data and Nile River flow data additionally.

Comparison of multiscale multiple change-points estimators (SMUCE와 FDR segmentation 방법에 의한 다중변화점 추정법 비교)

  • Kim, Jaehee
    • The Korean Journal of Applied Statistics
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    • v.32 no.4
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    • pp.561-572
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    • 2019
  • We study false discovery rate segmentation (FDRSeg) and simultaneous multiscale change-point estimator (SMUCE) methods for multiscale multiple change-point estimation, and compare empirical behavior via simulation. FSRSeg is based on the control of a false discovery rate while SMUCE used for the multiscale local likelihood ratio tests. FDRSeg seems to work best if the number of change-points is large; however, FDRSeg and SMUCE methods can both provide similar estimation results when there are only a small number of change-points. As a real data application, multiple change-points estimation is done with the well-log data.

Software Reliability Model with Multiple Change-Points (소프트웨어 신뢰도 모형에서 다중 변화점 문제)

  • Dong Hoon Lim;Dong Hee Kim
    • The Korean Journal of Applied Statistics
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    • v.7 no.2
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    • pp.101-111
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    • 1994
  • In this paper, we can see that software reliability model has been improved by considering multiple change-points. The condition for the existence of maximum likelihood estimate of the initial error content of a program is given and the maximum likelihood estimations of multiple change-points are derived. We assess the performance of our multiple change-points model on numerical applicaiton.

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Multiple Structural Change-Point Estimation in Linear Regression Models

  • Kim, Jae-Hee
    • Communications for Statistical Applications and Methods
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    • v.19 no.3
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    • pp.423-432
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    • 2012
  • This paper is concerned with the detection of multiple change-points in linear regression models. The proposed procedure relies on the local estimation for global change-point estimation. We propose a multiple change-point estimator based on the local least squares estimators for the regression coefficients and the split measure when the number of change-points is unknown. Its statistical properties are shown and its performance is assessed by simulations and real data applications.

Multiple change-point estimation in spectral representation

  • Kim, Jaehee
    • Communications for Statistical Applications and Methods
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    • v.29 no.1
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    • pp.127-150
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    • 2022
  • We discuss multiple change-point estimation as edge detection in piecewise smooth functions with finitely many jump discontinuities. In this paper we propose change-point estimators using concentration kernels with Fourier coefficients. The change-points can be located via the signal based on Fourier transformation system. This method yields location and amplitude of the change-points with refinement via concentration kernels. We prove that, in an appropriate asymptotic framework, this method provides consistent estimators of change-points with an almost optimal rate. In a simulation study the proposed change-point estimators are compared and discussed. Applications of the proposed methods are provided with Nile flow data and daily won-dollar exchange rate data.

Bayesian Procedure for the Multiple Change Point Analysis of Fraction Nonconforming (부적합률의 다중변화점분석을 위한 베이지안절차)

  • Kim, Kyung-Sook;Kim, Hee-Jeong;Park, Jeong-Soo;Son, Young-Sook
    • Proceedings of the Korean Society for Quality Management Conference
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    • 2006.04a
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    • pp.319-324
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    • 2006
  • In this paper, we propose Bayesian procedure for the multiple change points analysis in a sequence of fractions nonconforming. We first compute the Bayes factor for detecting the existence of no change, a single change or multiple changes. The Gibbs sampler with the Metropolis-Hastings subchain is run to estimate parameters of the change point model, once the number of change points is identified. Finally, we apply the results developed in this paper to both a real and simulated data.

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Multiple Change-Point Estimation of Air Pollution Mean Vectors

  • Kim, Jae-Hee;Cheon, Sooy-Oung
    • The Korean Journal of Applied Statistics
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    • v.22 no.4
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    • pp.687-695
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    • 2009
  • The Bayesian multiple change-point estimation has been applied to the daily means of ozone and PM10 data in Seoul for the period 1999. We focus on the detection of multiple change-points in the ozone and PM10 bivariate vectors by evaluating the posterior probabilities and Bayesian information criterion(BIC) using the stochastic approximation Monte Carlo(SAMC) algorithm. The result gives 5 change-points of mean vectors of ozone and PM10, which are related with the seasonal characteristics.

Bayesian Multiple Change-Point Estimation for Single Quantum Dot Luminescence Intensity Data (단일 양자점으로부터 발생한 발광세기 변화에 대한 베이지안 다중 변화점 추정)

  • Kima, Jaehee;Kimb, Hahkjoon
    • The Korean Journal of Applied Statistics
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    • v.26 no.4
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    • pp.569-579
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    • 2013
  • In the field of single-molecule spectroscopy, it is essential to analyze luminescence Intensity changes that result from a single molecule. With the CdSe/ZnS core-shell structured quantum dot photon emission data Bayesian multiple change-point estimation is done with the gamma prior for Poisson parameters and truncated Poisson distribution for the number of change-points.

Detection of Change-Points by Local Linear Regression Fit;

  • Kim, Jong Tae;Choi, Hyemi;Huh, Jib
    • Communications for Statistical Applications and Methods
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    • v.10 no.1
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    • pp.31-38
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    • 2003
  • A simple method is proposed to detect the number of change points and test the location and size of multiple change points with jump discontinuities in an otherwise smooth regression model. The proposed estimators are based on a local linear regression fit by the comparison of left and right one-side kernel smoother. Our proposed methodology is explained and applied to real data and simulated data.