• Title/Summary/Keyword: prediction error method

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Air Flow Prediction and Experiment by T-Method According to Duct Layout on House Ventilation System (주택환기시스템의 덕트 Layout에 따른 T-Method의 풍량 예측 및 실험)

  • Joo, Sung-Yong;Yee, Jurng-Jae
    • Proceedings of the SAREK Conference
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    • 2008.06a
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    • pp.523-528
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    • 2008
  • The accurate distribution of flow rate has been a very important part to control the air change rate since introduction of house ventilation system. An inappropriate selection of fan due to incorrect prediction of pressure loss in duct brings energy loss. In the previous study the pressure loss of general spiral duct was measured and database was constructed for finding correct loss factors in fitting upper stream. The purpose of this study is to compare and investigate the error range of flow rate by applying T-Method to bilateral symmetry and asymmetry layout of duct. The results of this study are as following. It is demanded to decide accurate size under duct design for house ventilation system. Because the small amount of Flow rate was considered at that time. The error range was 3.17% on case1 and 3.52% on case2. The error range difference was 0.35%.

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A Simple Bias-Correction Rule for the Apparent Prediction Error

  • Beong-Soo So
    • Communications for Statistical Applications and Methods
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    • v.2 no.2
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    • pp.146-154
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    • 1995
  • By using simple Taylor expansion, we derive an easy bias-correction rule for the apparent prodiction error of the predictor defined by the general M-estimators with respect to an arbitrary measure of prediction error. Our method has a considerable computational advantage over the previous methods based on the resampling thchnique such as Cross-validaton and Boothtrap. Connections with AIC, Cross-Validation and Boothtrap are discussed too.

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A Study on the Parameter Estimation Algorithm for Nonlinear Systems (비선형 시스템의 계수추정 알고리즘 연구)

  • Lee, Dal-Ho;Seong, Sang-Man
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.48 no.7
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    • pp.898-902
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    • 1999
  • In this paper, we proposed an algorithm for estimating parameters of nonlinear continuous-discrete state-space system. This algorithm uses the conventional extended Kalman filter(EKF) for estimating state variables, and modifies the recursive prediction error method for parameter estimation of the nonlinear system. Simulation results for both linear and nonlinear measurements under the environment of process and measurement noises show a convincing performance of the proposed algorithm.

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IDENTIFICATION OF MODAL PARAMETERS BY SEQUENTIAL PREDICTION ERROR METHOD (순차적 예측오차 방법에 의한 구조물의 모우드 계수 추정)

  • Lee, Chang-Guen;Yun, Chung-Bang
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1990.10a
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    • pp.79-84
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    • 1990
  • The modal parameter estimations of linear multi-degree-of-freedom structural dynamic systems are carried out in time domain. For this purpose, the equation of motion is transformed into the autoregressive and moving average model with auxiliary stochastic input (ARMAX) model. The parameters of the ARMAX model are estimated by using the sequential prediction error method. Then, the modal parameters of the system are obtained thereafter. Experimental results are given for a 3-story building model subject to ground exitations.

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A New Approach for Autofocusing in Microscopy

  • Tsomko, Elena;Kim, Hyoung-Joong;Han, Hyoung-Seok
    • 한국정보통신설비학회:학술대회논문집
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    • 2008.08a
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    • pp.186-189
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    • 2008
  • In order to estimate cell images, high-performance electron microscopes are used nowadays. In this paper, we propose a new simple, fast and efficient method for real-time automatic focusing in electron microscopes. The proposed algorithm is based on the prediction-error variance, and demonstrates its feasibility by using extensive experiments. This method is fast, easy to implement, accurate, and not demanding on computation time.

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Optimal Cutting Condition in Side Wall Milling Considering Form Accuracy (측벽 엔드밀 가공에서 형상 정밀도를 고려한 최적 절삭 조건)

  • 류시형;최덕기;주종남
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.10
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    • pp.31-40
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    • 2003
  • In this paper, optimal cutting condition to minimize the form error in side wall machining with a flat end mill is studied. Cutting forces and tool deflection are calculated considering surface shape generated by the previous cutting such as roughing. Using the form error prediction method from tool deflection, optimal cutting condition considering form accuracy is investigated. Also, the effects of tool teeth number, tool geometry and cutting conditions on form error are analyzed. The characteristics and the difference of generated surface shape in up and down milling are discussed and over-cut free condition in up milling is presented. Form error reduction method through successive up and down milling is also suggested. The effectiveness and usefulness of the presented method are verified from a series of cutting experiments under various cutting conditions. It is confirmed that form error prediction from tool deflection in side wall machining can be used in optimal cutting condition selection and real time surface error simulation for CAD/CAM systems. This study also contributes to cutting process optimization for the improvement of form accuracy especially in precision die and mold manufacturing.

LM-BP algorithm application for odour classification and concentration prediction using MOS sensor array (MOS 센서어레이를 이용한 냄새 분류 및 농도추정을 위한 LM-BP 알고리즘 응용)

  • 최찬석;변형기;김정도
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.210-210
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    • 2000
  • In this paper, we have investigated the properties of multi-layer perceptron (MLP) for odour patterns classification and concentration estimation simultaneously. When the MLP may be has a fast convergence speed with small error and excellent mapping ability for classification, it can be possible to use for classification and concentration prediction of volatile chemicals simultaneously. However, the conventional MLP, which is back-Propagation of error based on the steepest descent method, was difficult to use for odour classification and concentration estimation simultaneously, because it is slow to converge and may fall into the local minimum. We adapted the Levenberg-Marquardt(LM) algorithm [4,5] having advantages both the steepest descent method and Gauss-Newton method instead of the conventional steepest descent method for the simultaneous classification and concentration estimation of odours. And, We designed the artificial odour sensing system(Electronic Nose) and applied LM-BP algorithm for classification and concentration prediction of VOC gases.

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A Study on the Virtual Machining CAM System : Prediction and Experimental Verification of Machined Surface (실 가공형 CAM 시스템 연구: 가공형상의 예측 및 실험 검증)

  • 김형우;서석환;신창호
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1995.10a
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    • pp.961-964
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    • 1995
  • For geometric accuracy in the net shape machining, the problem of tool deflection should be resolved in some fashion. In particular, this is crucial in finish cut operation where slim tools are used. The purpose of this paper is to verify the validity and effectiveness of the prediction model of the machined surface. Experimental results are presented for the cut of steel material with HSS endmill of diameter 6mm on machining center. The results shows that 1) the machining error due totool deflection is serious even in the low cutting load, 2) by using the mechanistic simulation model with experimental coefficients, the machining error was predicted with maximum prediction error of 10% which was significantly reduced to the desired level by the path modification method.

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Least Square Prediction Error Expansion Based Reversible Watermarking for DNA Sequence (최소자승 예측오차 확장 기반 가역성 DNA 워터마킹)

  • Lee, Suk-Hwan;Kwon, Seong-Geun;Kwon, Ki-Ryong
    • Journal of the Institute of Electronics and Information Engineers
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    • v.52 no.11
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    • pp.66-78
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    • 2015
  • With the development of bio computing technology, DNA watermarking to do as a medium of DNA information has been researched in the latest time. However, DNA information is very important in biologic function unlikely multimedia data. Therefore, the reversible DNA watermarking is required for the host DNA information to be perfectively recovered. This paper presents a reversible DNA watermarking using least square based prediction error expansion for noncodng DNA sequence. Our method has three features. The first thing is to encode the character string (A,T,C,G) of nucleotide bases in noncoding region to integer code values by grouping n nucleotide bases. The second thing is to expand the prediction error based on least square (LS) as much as the expandable bits. The last thing is to prevent the false start codon using the comparison searching of adjacent watermarked code values. Experimental results verified that our method has more high embedding capacity than conventional methods and mean prediction method and also makes the prevention of false start codon and the preservation of amino acids.

Advanced Pixel Value Prediction Algorithm using Edge Characteristics in Image

  • Jung, Soo-Mok
    • International Journal of Internet, Broadcasting and Communication
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    • v.12 no.1
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    • pp.111-115
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    • 2020
  • In this paper, I proposed an effective technique for accurately predicting pixel values using edge components. Adjacent pixel values are similar to each other. That is, generally, similarity exists between adjacent pixels in an image. In the proposed algorithm, edge components are detected using the surrounding pixels in the first step, and pixel values are estimated using the edge components in the second step. Therefore, the prediction accuracy of the pixel value is improved and the prediction error is reduced. Pixel value prediction is a necessary technique for various applications such as image magnification and confidential data concealment. Experimental results show that the proposed method has higher prediction accuracy and fewer prediction error. Therefore, the proposed technique can be effectively used for applications such as image magnification and confidential data concealment.