• Title/Summary/Keyword: Autoregressive Model

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Real-Time Flood Forecasting System For the Keum River Estuary Dam(II) -System Application- (금강하구둑 홍수예경보시스템 개발(II) -시스템의 적용-)

  • 정하우;이남호;김현영;김성준
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.36 no.3
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    • pp.60-66
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    • 1994
  • This paper is to validate the proposed models for the real-time forecasting for the Keum river estuary dam such as tidal-level forecasting model, one-dimensional unsteady flood routing model, and Kalman filter models. The tidal-level forecasting model was based on semi-range and phase lag of four tidal constituents. The dynamic wave routing model was based on an implicit finite difference solution of the complete one-dimensional St. Venant equations of unsteady flow. The Kalman filter model was composed of a processing equation and adaptive filtering algorithm. The processng equations are second ordpr autoregressive model and autoregressive moving average model. Simulated results of the models were compared with field data and were reviewed.

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Development of the Automated Irrigation Management System for Paddy Fields (논 물 관리의 자동화시스템 개발)

  • 정하우;이남호;김성준;최진용;김대식
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.36 no.3
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    • pp.67-73
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    • 1994
  • This paper is to validate the proposed models for the real-time forecasting for the Keum river estuary dam such as tidal-level forecasting model, one-dimensional unsteady flood routing model, and Kalman filter models. The tidal-level forecasting model was based on semi-range and phase lag of four tidal constituents. The dynamic wave routing model was based on an implicit finite difference solution of the complete one-dimensional St. Venant equations of unsteady flow. The Kalman filter model was composed of a processing equation and adaptive filtering algorithm. The processng equations are second ordpr autoregressive model and autoregressive moving average model. Simulated results of the models were compared with field data and were reviewed.

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Analysis of PM10 Concentration using Auto-Regressive Error Model at Pyeongtaek City in Korea (자기회귀오차모형을 이용한 평택시 PM10 농도 분석)

  • Lee, Hoon-Ja
    • Journal of Korean Society for Atmospheric Environment
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    • v.27 no.3
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    • pp.358-366
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    • 2011
  • The purpose of this study was to analyze the monthly and seasonal PM10 data using the Autoregressive Error (ARE) model at the southern part of the Gyeonggi-Do, Pyeongtaek monitoring site in Korea. In the ARE model, six meteorological variables and four pollution variables are used as the explanatory variables. The six meteorological variables are daily maximum temperature, wind speed, amount of cloud, relative humidity, rainfall, and global radiation. The four air pollution variables are sulfur dioxide ($SO_2$), nitrogen dioxide ($NO_2$), carbon monoxide (CO), and ozone ($O_3$). The result shows that monthly ARE models explained about 17~49% of the PM10 concentration. However, the ARE model could be improved if we add the more explanatory variables in the model.

Wind velocity simulation of spatial three-dimensional fields based on autoregressive model

  • Gao, Wei-Cheng;Yu, Yan-Lei
    • Wind and Structures
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    • v.11 no.3
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    • pp.241-256
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    • 2008
  • This paper adopts autoregressive (AR) model to simulate the wind velocity of spatial three-dimensional fields in accordance with the time and space dependent characteristics of the 3-D fields. Based on the built MATLAB programming, this paper discusses in detail the issues of the AR model deduced by matrix form in the simulation and proposes the corresponding solving methods: the over-relaxation iteration to solve the large sparse matrix equations produced by large number of degrees of freedom of structures; the improved Gauss formula to calculate the numerical integral equations which integral functions contain oscillating functions; the mixed congruence and central limit theorem of Lindberg-Levy to generate random numbers. This paper also develops a method of ascertaining the rank of the AR model. The numerical examples show that all those methods are stable and reliable, which can be used to simulate the wind velocity of all large span structures in civil engineering.

An Experimental Study on Realtime Estimation of a Nominal Model for a Disturbance Observer: Recursive Least Squares Approach (실시간 공칭 모델 추정 외란관측기에 관한 실험 연구: 재귀최소자승법)

  • Lee, Sang-Deok;Jung, Seul
    • Journal of Institute of Control, Robotics and Systems
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    • v.22 no.8
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    • pp.650-655
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    • 2016
  • In this paper, a novel RLS-based DOB (Recursive Least Squares Disturbance Observer) scheme is proposed to improve the performance of DOB for nominal model identification. A nominal model can be generally assumed to be a second order system in the form of a proper transfer function of an ARMA (Autoregressive Moving Average) model. The RLS algorithm for the model identification is proposed in association with DOB. Experimental studies of the balancing control of a one-wheel robot are conducted to demonstrate the feasibility of the proposed method. The performances between the conventional DOB scheme and the proposed scheme are compared.

Weekly maximum power demand forecasting using model in consideration of temperature estimation (기온예상치를 고려한 모델에 의한 주간최대전력수요예측)

  • 고희석;이충식;김종달;최종규
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.45 no.4
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    • pp.511-516
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    • 1996
  • In this paper, weekly maximum power demand forecasting method in consideration of temperature estimation using a time series model was presented. The method removing weekly, seasonal variations on the load and irregularities variation due to unknown factor was presented. The forecasting model that represent the relations between load and temperature which get a numeral expected temperature based on the past 30 years(1961~1990) temperature was constructed. Effect of holiday was removed by using a weekday change ratio, and irregularities variation was removed by using an autoregressive model. The results of load forecasting show the ability of the method in forecasting with good accuracy without suffering from the effect of seasons and holidays. Percentage error load forecasting of all seasons except summer was obtained below 2 percentage. (author). refs., figs., tabs.

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Outlier Detection of Autoregressive Models Using Robust Regression Estimators (로버스트 추정법을 이용한 자기상관회귀모형에서의 특이치 검출)

  • Lee Dong-Hee;Park You-Sung;Kim Kee-Whan
    • The Korean Journal of Applied Statistics
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    • v.19 no.2
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    • pp.305-317
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    • 2006
  • Outliers adversely affect model identification, parameter estimation, and forecast in time series data. In particular, when outliers consist of a patch of additive outliers, the current outlier detection procedures suffer from the masking and swamping effects which make them inefficient. In this paper, we propose new outlier detection procedure based on high breakdown estimators, called as the dual robust filtering. Empirical and simulation studies in the autoregressive model with orders p show that the proposed procedure is effective.

Statistical Inference for Space Time Series Model with Application to Mumps Data

  • Jeong, Ae-Ran;Kim, Sun-Woo;Lee, Sung-Duck
    • Journal of the Korean Data and Information Science Society
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    • v.17 no.2
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    • pp.475-486
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    • 2006
  • Space time series data can be viewed either as a set of time series collected simultaneously at a number of spatial locations or as sets of spatial data collected at a number of time points. The major purpose of this article is to formulate a class of space time autoregressive moving average (STARMA) model, to discuss some of the their statistical properties such as model identification approaches, some procedure for estimation and the predictions. For illustration, we apply this STARMA model to the mumps data. The data set of mumps cases consists of the number of cases of mumps reported from twelve states monthly over the years 1969-1988.

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Models for forecasting food poisoning occurrences (식중독 발생 예측모형)

  • Yeo, In-Kwon
    • Journal of the Korean Data and Information Science Society
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    • v.23 no.6
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    • pp.1117-1125
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    • 2012
  • The occurrence of food poisoning is usually modeled by meteorological variables like the temperature and the humidity. In this paper, we investigate the relationship between food poisoning occurrence and climate variables in Korea and compare Poisson regression and autoregressive moving average model to select the forecast model. We confirm that lagged climate variables affect the food poisoning occurrences. However, it turns out that, from the viewpoint of the prediction, the number of previous occurrences is more influential to the current occurrence than meteorological variables and Poisson regression model is less reliable.

Small Area Estimation Using Bayesian Auto Poisson Model with Spatial Statistics (공간통계량을 활용한 베이지안 자기 포아송 모형을 이용한 소지역 통계)

  • Lee, Sang-Eun
    • The Korean Journal of Applied Statistics
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    • v.19 no.3
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    • pp.421-430
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    • 2006
  • In sample survey sample designs are performed by geographically-based domain such as countries, states and metropolitan areas. However mostly statistics of interests are smaller domain than sample designed domain. Then sample sizes are typically small or even zero within the domain of interest. Shin and Lee(2003) mentioned Spatial Autoregressive(SAR) model in small area estimation model-based method and show the effectiveness by MSE. In this study, Bayesian Auto-Poisson Model is applied in model-based small area estimation method and compare the results with SAR model using MSE ME and bias check diagnosis using regression line. In this paper Survey of Disability, Aging and Cares(SDAC) data are used for simulation studies.