• 제목/요약/키워드: change points

검색결과 1,791건 처리시간 0.029초

순열검정을 이용한 FLSA의 사후추론 (Permutation test for a post selection inference of the FLSA)

  • 최지은;손원
    • 응용통계연구
    • /
    • 제34권6호
    • /
    • pp.863-874
    • /
    • 2021
  • FLSA는 총변동벌점을 이용해 구간별상수인 평균 구조를 구현하는 벌점모형으로 다중변화점 탐색을 위해 활용되고 있다. 한편, FLSA는 변화점 탐색에 있어서 점근적 일치성이 만족되지 않으므로 잡음의 크기가 0에 가깝게 수렴하는 경우에도 다수의 거짓 변화점이 식별될 수 있다는 단점이 있다. 이 연구에서는 이러한 FLSA의 문제점을 해결하기 위한 사후추론 방법으로 순열검정 방법을 제안한다. 단일변화점 모형과 관련된 순열검정 방법은 Antoch와 Hušková (2001)에 의해 제안된 바 있다. 이 연구에서는 Antoch와 Hušková (2001)의 검정절차를 확장하여 다중변화점 식별에 사용되는 FLSA와 결합함으로써 다중변화점 모형에 적용할 수 있는 순열검정절차를 제안한다. 모의실험 결과, 제안된 방법은 z-검정과 CUSUM 통계량의 극한분포에 기반을 둔 검정방법에 비해 전반적으로 우수하였으며 거짓 변화점의 식별에 유용함을 확인할 수 있었다.

Change-Points with Jump in Nonparametric Regression Functions

  • Kim, Jong-Tae
    • 한국데이터정보과학회:학술대회논문집
    • /
    • 한국데이터정보과학회 2005년도 춘계학술대회
    • /
    • pp.193-199
    • /
    • 2005
  • A simple method is proposed to detect the number of change points with jump discontinuities in nonparamteric regression functions. The proposed estimators are based on a local linear regression fit by the comparison of left and right one-side kernel smoother. Also, the proposed methodology is suggested as the test statistic for detecting of change points and the direction of jump discontinuities.

  • PDF

Detection of Change-Points by Local Linear Regression Fit;

  • Kim, Jong Tae;Choi, Hyemi;Huh, Jib
    • Communications for Statistical Applications and Methods
    • /
    • 제10권1호
    • /
    • pp.31-38
    • /
    • 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.

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

  • Dong Hoon Lim;Dong Hee Kim
    • 응용통계연구
    • /
    • 제7권2호
    • /
    • pp.101-111
    • /
    • 1994
  • 본 논문은 소프트웨어 신뢰도 모형에서 다중 변화점을 고려함으로서 미래의 관찰치에 대한 예측 성능을 높일 수 있는 새로운 모형에서 프로그램 에러수의 최우추정량이 유한일 조건을 제시하고, 변화점 추정 방법에 대해 논의한다. 또한, 제안된 모형의 타당성을 조사하기 위해 실제 예제를 통하여 모형 성능을 평가한다.

  • PDF

Multiple Structural Change-Point Estimation in Linear Regression Models

  • Kim, Jae-Hee
    • Communications for Statistical Applications and Methods
    • /
    • 제19권3호
    • /
    • pp.423-432
    • /
    • 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.

CHANGE-POINT DETECTION WITH SPLIT LINEAR FITS

  • Kim, Jae-Hee
    • Journal of applied mathematics & informatics
    • /
    • 제8권2호
    • /
    • pp.641-649
    • /
    • 2001
  • A procedure of detecting change-points is considered with split linear fitting idea from Hall and Titterington(1992). At each given point, left, central and right linear fits are compared to detect the discontinuities or change-points. A simulation study is done with various types of change models and shows that the suggested technique can be a flexible data-analytic tool.

Two-Stage forecasting Using Change-Point Detection and Artificial Neural Networks for Stock Price Index

  • Oh, Kyong-Joo;Kim, Kyoung-Jae;Ingoo Han
    • 한국지능정보시스템학회:학술대회논문집
    • /
    • 한국지능정보시스템학회 2000년도 추계정기학술대회:지능형기술과 CRM
    • /
    • pp.427-436
    • /
    • 2000
  • The prediction of stock price index is a very difficult problem because of the complexity of the stock market data it data. It has been studied by a number of researchers since they strong1y affect other economic and financial parameters. The movement of stock price index has a series of change points due to the strategies of institutional investors. This study presents a two-stage forecasting model of stock price index using change-point detection and artificial neural networks. The basic concept of this proposed model is to obtain Intervals divided by change points, to identify them as change-point groups, and to use them in stock price index forecasting. First, the proposed model tries to detect successive change points in stock price index. Then, the model forecasts the change-point group with the backpropagation neural network (BPN). Fina1ly, the model forecasts the output with BPN. This study then examines the predictability of the integrated neural network model for stock price index forecasting using change-point detection.

  • PDF

실질금리 결정모형에서의 구조변화분석 (Structural Change Analysis in a Real Interest Rate Model)

  • 전덕빈;박대근
    • 경영과학
    • /
    • 제18권1호
    • /
    • pp.119-133
    • /
    • 2001
  • It is important to find the equilibrium level of real interest rate for it affects real and financial sector of economy. However, it is difficult to find the equilibrium level because like the most macroeconomic model the real interest model has parameter instability problem caused by structural change and it is supported by various theories and definitions. Hence, in order to cover these problems structural change detection model of real interest rate is developed to combine the real interest rate equilibrium model and the procedure to detect structural change points. 3 equations are established to find various effects of other interest-related macroeconomic variables and from each equation, structural changes are found. Those structural change points are consistent with common expectation. Oil Crisis (December, 1987), the starting point of Economic Stabilization Policy (January, 1982), the starting point of capital liberalization (January, 1988), the starting and finishing points of Interest deregulation (January, 1992 and December, 1994), Foreign Exchange Crisis (December, 1977) are detected as important points. From the equation of fisher and real effects, real interest rate level is estimated as 4.09% (October, 1988) and dependent on the underlying model, it is estimated as 0%∼13.56% (October, 1988), so it varies so much. It is expected that this result is connected to the large scale simultaneous equations to detect the parameter instability in real time, so induces the flexible economic policies.

  • PDF

안면도 바람아래 할미섬 주변의 시계열적 침식·퇴적환경 변화 분석 (A Time-Series Analysis of the Erosion and Deposition around Halmi-island, Baramarae)

  • 유재진;김장수;장동호
    • 한국지형학회지
    • /
    • 제23권1호
    • /
    • pp.47-60
    • /
    • 2016
  • In this study, datum points measurement have been collected and then weather data have been analyzed to figure out erosion and deposition environmental change around Halmi-island, Baramarae. First of all, it was difficult to analyze geomorphological change which is caused by climate change because of quite short term of collection period of data. However, differences in spatial distribution of erosion and deposition have locally been shown. In all season, the wind is blowing in north and north-west direction mostly except in summer which is shifted to south direction. However, since its ratio which are above 5m/s is much lower than the north and north-west wind, its effect on geomorphological process is very tiny. In order to look at a tendency of erosion and deposition environmental change around Baramarae Halmi-island, the periphery of Halmi-island was classified to east and west part, then accumulated erosion and deposition values have been calculated. As a result, generally, the datum points are located in the west part which are mostly depositional sites. On the other hand, the datum points are located in east part showed the dominant erosion patterns.

Neural Network Modeling supported by Change-Point Detection for the Prediction of the U.S. Treasury Securities

  • Oh, Kyong-Joo;Ingoo Han
    • 한국경영과학회:학술대회논문집
    • /
    • 한국경영과학회 2000년도 추계학술대회 및 정기총회
    • /
    • pp.37-39
    • /
    • 2000
  • The purpose of this paper is to present a neural network model based on change-point detection for the prediction of the U.S. Treasury Securities. Interest rates have been studied by a number of researchers since they strongly affect other economic and financial parameters. Contrary to other chaotic financial data, the movement of interest rates has a series of change points due to the monetary policy of the U.S. government. The basic concept of this proposed model is to obtain intervals divided by change points, to identify them as change-point groups, and to use them in interest rates forecasting. The proposed model consists of three stages. The first stage is to detect successive change points in the interest rates dataset. The second stage is to forecast the change-point group with the backpropagation neural network (BPN). The final stage is to forecast the output with BPN. This study then examines the predictability of the integrated neural network model for interest rates forecasting using change-point detection.

  • PDF