• Title/Summary/Keyword: Autoregressive (AR)

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Markov Chain Approach to Forecast in the Binomial Autoregressive Models

  • Kim, Hee-Young;Park, You-Sung
    • Communications for Statistical Applications and Methods
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    • v.17 no.3
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    • pp.441-450
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    • 2010
  • In this paper we consider the problem of forecasting binomial time series, modelled by the binomial autoregressive model. This paper considers proposed by McKenzie (1985) and is extended to a higher order by $Wei{\ss}$(2009). Since the binomial autoregressive model is a Markov chain, we can apply the earlier work of Bu and McCabe (2008) for integer valued autoregressive(INAR) model to the binomial autoregressive model. We will discuss how to compute the h-step-ahead forecast of the conditional probabilities of $X_{T+h}$ when T periods are used in fitting. Then we obtain the maximum likelihood estimator of binomial autoregressive model and use it to derive the maximum likelihood estimator of the h-step-ahead forecast of the conditional probabilities of $X_{T+h}$. The methodology is illustrated by applying it to a data set previously analyzed by $Wei{\ss}$(2009).

A Formula for Computing the Autocorrelations of the AR Process

  • Cho, Sung-Ho
    • The Journal of the Acoustical Society of Korea
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    • v.15 no.2E
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    • pp.4-7
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    • 1996
  • In this paper, we propose a formula to compute the exact autocorrelations of the autoregressive (AR) process. For an arbitrary value of N, we first review the Yule-Walker equation and some basic properties of the AR model. We then modify the Yule-Walker equation to construct a new system of N+1 linear equations that can be used to solve for the N+1 autocorrelation coefficients for lags 0, 1, …, N, provided that the AR parameters of order N and the power of the white noise of the AR process are given.

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A Study on the Pattern Recognition of EMG Signals for Head Motion Recognition (머리 움직임 인식을 위한 근전도 신호의 패턴 인식 기법에 관한 연구)

  • 이태우;전창익;이영석;유세근;김성환
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.53 no.2
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    • pp.103-110
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    • 2004
  • This paper proposes a new method on the EMG AR(autoregressive) modeling in pattern recognition for various head motions. The proper electrode placement in applying AR or cepstral coefficients for EMG signature discrimination is investigated. EMG signals are measured for different 10 motions with two electrode arrangements simultaneously. Electrode pairs are located separately on dominant muscles(S-type arrangement), because the bandwidth of signals obtained from S-type placement is wider than that from C-type(closely in the region between muscles). From the result of EMG pattern recognition test, the proposed mIAR(modified integrated mean autoregressive model) technique improves the recognitions rate around 17-21% compared with other the AR and cepstral methods.

Statistical Design of VSS $\overline{A}$ Charts for Monitoring an AR(1) Process (AR(l) 공정을 탐지하는 VSS $\overline{A}$ 관리도의 통계적 설계)

  • 이재헌
    • Journal of Korean Society for Quality Management
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    • v.31 no.3
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    • pp.126-135
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    • 2003
  • A basic assumption in standard applications of control charts is that the observations are statistically independent. However, this assumption is often violated from processes in many industries. The presence of autocorrelation has a serious impact on the performance of control charts, causing a dramatic increase in the frequency of false alarms. This paper considers a process in which the observations can be modeled as a first order autoregressive(AR(1)) process, and develops (equation omitted) charts with the variable sample size(VSS) scheme for monitoring the mean of this process.

Characterization of Surface Quality in Orthogonal Cutting of Glass Fiber Reinforced Plastics

  • Choi Gi Heung
    • International Journal of Safety
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    • v.3 no.1
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    • pp.1-5
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    • 2004
  • This study discusses frequency analysis based on autoregressive (AR) time series model, and the characterization of surface quality in orthogonal cutting of a fiber-matrix composite materials. A sparsely distributed idealized composite material, namely a glass reinforced polyester (GFRP) was used as workpiece. Analysis method employs a force sensor and the signals from the sensor are processed using AR time series model. The experimental correlations between the fiber pull-out and AR model coefficients are then established.

A Study on Analysis of Time Delay Model Using Autoregressive Method for Mobile Communication Channels (AR 모델을 이용한 이동 통신 채널의 시간 지연 해석기법에 관한 연구)

  • 이형권;류은숙;이종길
    • Proceedings of the IEEK Conference
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    • 1999.06a
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    • pp.29-32
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    • 1999
  • In this study, the time delay model were simulated using the well-known AR model. Frequency response of the time delay model can be obtained by mapping AR model to JTC model in the time domain. That is, from the few measurement data in JTC model, the channel frequency response can be obtained by the estimation of AR model parameters. From this channel frequency response, the time delay model can be obtained using Fourier transformation. To prove the validity of the suggested method, three models of JTC were shown and analyzed.

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Convergence Behavior Analysis of The Maximally Polyphase Decomposed SAP Adaptive Filter (최대 다위상 분해 부밴드 인접투사 적응필터의 수렴거동 해석)

  • Choi, Hun;Bae, Hyeon-Deok
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.46 no.6
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    • pp.163-174
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    • 2009
  • Applying the maximally polyphase decomposition and noble identity to the adaptive filter in subband structure, the conventional fullband affine projection algorithm is translated to the subband affine projection (SAP) algorithm. The Maximally polyphase decomposed SAP (MPDSAP) algorithm is a special version of the SAP algorithm, and its adaptive sub-filters have unity projection dimension. The weight updating formular of the MPDSAP is similar to that of the NLMS algorithm, so it may be more proper algorithm than other AP-type algorithms for many practical applications. This paper presents a new statistical analysis of the MPDSAP algorithm. The analytical model is derived for autoregressive (AR) inputs and the nonunity adaptive gain in the subband structure with the orthonormal analysis filters (OAF), The pre-whitening by the OAF allows the derivation of a simple-analytical model for the MPDSAP with the AR inputs and the nonunity adaptive gain.

A Study on the Analysis of Ciliary Beat Frequency in Human Respiratory Tract n Vivo (레이저 산란 기법을 이용한 인체 기도 내 섬모 운동 신호의 분석에 관한 연구)

  • 이원진;이재서;이재서;이철희;권태영
    • Journal of Biomedical Engineering Research
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    • v.21 no.4
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    • pp.339-344
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    • 2000
  • The mucociliary system is one of the most important airway defense mechanisms in human body and impairment of ciliary movement results in various diseases in respiratory tract. In this study, we have developed a system that can measure ciliary movement in vivo and quantified ciliary beat frequency (CBF) through autoregressive (AR) power spectrum. To measure the frequency in vivo, we applied a photoelectric method that was composed of a laser light and a fiber optic probe. Scattered signals are transferred to a PC in which they are displayed on the monitor and its CBF is determined by the AR method in were acquired. For 8 normal subjects, the analyzed CBFs ranged from 5 to 10Hz and its mean was 7.3${\pm}$1.1Hz. This result showed similar aspects to the reported results of CBFs to data. We expect that this result will be applied in various clinical studies such as analysis of CBF changes by drugs or by diseaes.

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Model selection for unstable AR process via the adaptive LASSO (비정상 자기회귀모형에서의 벌점화 추정 기법에 대한 연구)

  • Na, Okyoung
    • The Korean Journal of Applied Statistics
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    • v.32 no.6
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    • pp.909-922
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    • 2019
  • In this paper, we study the adaptive least absolute shrinkage and selection operator (LASSO) for the unstable autoregressive (AR) model. To identify the existence of the unit root, we apply the adaptive LASSO to the augmented Dickey-Fuller regression model, not the original AR model. We illustrate our method with simulations and a real data analysis. Simulation results show that the adaptive LASSO obtained by minimizing the Bayesian information criterion selects the order of the autoregressive model as well as the degree of differencing with high accuracy.